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University of Ontario Institute of Technology
1.
Patel, Amin.
Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices.
Degree: 2010, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/87
► Calculation of the neutron flux in a nuclear reactor core is ideally performed by solving the neutron transport equation for a detailed-geometry model using several…
(more)
▼ Calculation of the neutron flux in a nuclear
reactor core is ideally performed by solving the neutron transport equation for a detailed-geometry model using several tens of energy groups. However, performing such detailed calculations for an entire core is prohibitively expensive from a computational perspective. Full-core neutronic calculations for CANDU reactors are therefore performed customarily using two-energy-group diffusion theory (no angular dependence) for a node-homogenized
reactor model. The work presented here is concerned with reducing the loss in accuracy entailed when going from Transport to Diffusion. To this end a new method of calculating the diffusion coefficient was developed, based on equating the neutron balance equation expressed by the transport equation with the neutron balance equation expressed by the diffusion equation. The technique is tested on a simple twelve-node model and is shown to produce transport-like accuracy without the associated computational effort.
Advisors/Committee Members: Nichita, Eleodor M..
Subjects/Keywords: Applied reactor physics; Transport theory; Diffusion theory; CANDU; Nuclear reactor
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APA (6th Edition):
Patel, A. (2010). Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/87
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Patel, Amin. “Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices.” 2010. Thesis, University of Ontario Institute of Technology. Accessed February 16, 2019.
http://hdl.handle.net/10155/87.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Patel, Amin. “Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices.” 2010. Web. 16 Feb 2019.
Vancouver:
Patel A. Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices. [Internet] [Thesis]. University of Ontario Institute of Technology; 2010. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/10155/87.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Patel A. Transport-theory-equivalent diffusion coefficients for node-homogenized neutron diffusion problems in CANDU lattices. [Thesis]. University of Ontario Institute of Technology; 2010. Available from: http://hdl.handle.net/10155/87
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

The Ohio State University
2.
Kennedy, Ryanne Ariel.
Quantifying Uncertainty in Reactor Flux/Power
Distributions.
Degree: PhD, Nuclear Engineering, 2011, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1306360901
► The design and development of a conceptual system for power measurements in a reactor core using in-core sensors has been an ongoing focus of research…
(more)
▼ The design and development of a conceptual system for
power measurements in a
reactor core using in-core sensors has been
an ongoing focus of research performed at The Ohio State
University. Previous work focused on the development of software
that constructs three-dimensional core power distribution using
signals from an array of Constant Temperature Power Sensors
distributed in the
reactor core. The monitoring system processes
the sensor signals from the
reactor core in such a manner that
probabilistic information, in the form of probability distribution
functions (pdfs), of
reactor power density is obtained at the
sensor locations. The desired pdfs of power density at sensor
locations were obtained through the implementation of the
estimation algorithm Dynamic System Doctor (DSD). Additional work
in this area proposed methods to interpolate the pdfs at the
measurement points for uniform core compositions. The interpolation
methods presented in this thesis extend estimation of the
uncertainty in power/flux distribution to heterogeneous cores by
combining the knowledge from in-core sensors and
reactor core
neutron transport calculations. Two significant benefits of such an
estimation process are the following:1. It allows quantification of
the uncertainty on peaking factors as well as global power/flux
distributions and hence evaluation of potential for power
upgrades2. It provides data for a best-estimate quantification of
design margins.The interpolation method is an adaptation of an
interpolation procedure presented by L. Read and utilizes the
flux/power distributions obtained from a realistic
reactor core
model as interpolating functions. The pdfs at the interpolated
power/flux values are calculated using a weighted linear
interpolation of the sensor pdfs. Four weighting schemes are
considered for the power/flux interpolation algorithm. The proposed
interpolation methods and each weighting scheme are tested using
flux data from models of the Ohio State University Research
Reactor
(OSURR). The objective of the testing of each scheme is to
determine its accuracy/conservatism, and to gauge whether the
interpolation is physically representative of the process under
consideration. Different methods are compared as to their ability
to accurately estimate the pdfs at different positions in the
reactor core. In view of the uncertainty in the current material
composition of OSURR due to burnup of fuel during the past two
decades, the Monte Carlo code MCNP5 is used to generate the
“experimental data”. This approach also allows control of the
uncertainty on the tally results by changing the number of neutron
simulations performed. For the test problems, the OSURR core model
flux distributions used as distribution interpolating functions
(DIF) were generated by PENTRAN (Parallel Environment Neutral
particle Transport) 3-D discrete ordinates code (version 9.36k).
Three example problems were used to test the linear interpolation
schemes. In these three examples the interpolating method is
applied to the flux distribution in…
Advisors/Committee Members: Aldemir, Tunc (Advisor).
Subjects/Keywords: Nuclear Engineering; nuclear reactor; flux; uncertainty quantification; reactor physics
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APA (6th Edition):
Kennedy, R. A. (2011). Quantifying Uncertainty in Reactor Flux/Power
Distributions. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1306360901
Chicago Manual of Style (16th Edition):
Kennedy, Ryanne Ariel. “Quantifying Uncertainty in Reactor Flux/Power
Distributions.” 2011. Doctoral Dissertation, The Ohio State University. Accessed February 16, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1306360901.
MLA Handbook (7th Edition):
Kennedy, Ryanne Ariel. “Quantifying Uncertainty in Reactor Flux/Power
Distributions.” 2011. Web. 16 Feb 2019.
Vancouver:
Kennedy RA. Quantifying Uncertainty in Reactor Flux/Power
Distributions. [Internet] [Doctoral dissertation]. The Ohio State University; 2011. [cited 2019 Feb 16].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1306360901.
Council of Science Editors:
Kennedy RA. Quantifying Uncertainty in Reactor Flux/Power
Distributions. [Doctoral Dissertation]. The Ohio State University; 2011. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1306360901

Georgia Tech
3.
Abou Jaoude, Abdalla.
Design of a mixed-spectrum long-lived reactor with improved proliferation resistance.
Degree: PhD, Mechanical Engineering, 2017, Georgia Tech
URL: http://hdl.handle.net/1853/59275
► Long-lived fast reactors have been suggested as an effective way of spreading nuclear energy to new countries. These small reactors can be produced at centralized…
(more)
▼ Long-lived fast reactors have been suggested as an effective way of spreading nuclear energy to new countries. These small reactors can be produced at centralized locations, shipped to area of need, then returned to the main hub at the end of their lifetime for decommissioning. Such ‘hub-spoke’ arrangements disincentivizes states front building sensitive front and back-end technology; however, critics argue they still pose a proliferation risk due to the large quantity of weapon-grade plutonium they produce during their operating lifetime. The dissertation attempts to address this issue by proposing a mixed-spectrum core configuration. A fast neutron zone can increase fissile material production, while a thermalized zone reduces plutonium quality. Moderating material (ZrH1.6) is inserted within peripheral assemblies, while the center of the core maintains a fast configuration. Assemblies are then shuffled to ensure all are exposed to the thermalized spectrum. This allows the new design to simultaneously improve proliferation resistance and reduce fast fluence damage, a limiting criteria for long-lived core designs. The objectives are achieved with minimal impact on overall performance. Core lifetime can be maintained at 25 years, without the need for any additional fuel. Inherent passive safety criteria can be met, and power peaking phenomena at the fast/thermal interface was deemed to be manageable. Different design variants that can alleviate power peaking or leverage the ability of thorium-cycle breeding in the epithermal regime, were also investigated. Mixed-spectrum cores pushes the boundaries of what deterministic codes are capable of modeling accuracy. The REBUS suite of codes is modified to provide a more accurate tool to explore the design space. MCNP6 is then used for detailed analysis and safety evaluation of optimal core configurations. The thesis demonstrates the viability of using a mixed-spectrum
reactor design to improve proliferation resistance of long-lived cores. The main identified tradeoff was an increase in overall resource consumption, a slightly larger core size, and the reliance on shuffling midway through the core lifetime.
Advisors/Committee Members: Erickson, Anna (advisor), Petrovic, Bojan (committee member), Hertel, Nolan (committee member), Stulberg, Adam (committee member), Stauff, Nicolas (committee member).
Subjects/Keywords: Reactor physics; Proliferation resistance; Mixed-spectrum reactors; Reactor design; Safety evaluation
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Abou Jaoude, A. (2017). Design of a mixed-spectrum long-lived reactor with improved proliferation resistance. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59275
Chicago Manual of Style (16th Edition):
Abou Jaoude, Abdalla. “Design of a mixed-spectrum long-lived reactor with improved proliferation resistance.” 2017. Doctoral Dissertation, Georgia Tech. Accessed February 16, 2019.
http://hdl.handle.net/1853/59275.
MLA Handbook (7th Edition):
Abou Jaoude, Abdalla. “Design of a mixed-spectrum long-lived reactor with improved proliferation resistance.” 2017. Web. 16 Feb 2019.
Vancouver:
Abou Jaoude A. Design of a mixed-spectrum long-lived reactor with improved proliferation resistance. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1853/59275.
Council of Science Editors:
Abou Jaoude A. Design of a mixed-spectrum long-lived reactor with improved proliferation resistance. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59275

McMaster University
4.
McDonald, Michael H.
Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor.
Degree: MASc, 2011, McMaster University
URL: http://hdl.handle.net/11375/11223
► The supercritical water cooled reactor (SCWR) is a Generation IV reactor concept that features light water coolant in a supercritical state. Canada is developing…
(more)
▼ The supercritical water cooled reactor (SCWR) is a Generation IV reactor concept that features light water coolant in a supercritical state. Canada is developing a pressure tube variant of the supercritical water reactor as an evolution of the CANDU reactor. The main advantages of the pressure tube SCWR are an improved thermal efficiency over current reactors, enhanced safety through passive safety features, and plant simplifications. The objective of this thesis was to investigate current fuel and core designs for the Canadian SCWR concept. Simulations of 2-D lattice cells for fuel assemblies containing 43 and 54 fuel elements were performed using the neutron transport code WIMS-AECL. Safety parameters and fuel burnup performance were investigated here. Three dimensional full core simulations were performed using the diffusion code RFSP. These studies examined batch fueling, cycle length, radial and axial power profiles, linear element ratings, and reduction of axial power peaking through graded enrichment along the fuel channel. Finally, a study of reactivity transients was performed using the FUELPIN heat transfer/point kinetics code. The main results of the studies show that the coolant density change that occurs as water passes through the pseudocritical point strongly affects fuel performance. It is concluded that the 54 element assembly design is acceptable in terms of coolant void reactivity performance with lattice pitch smaller than 26 cm. To meet the burnup target, a fuel enrichment of about 5% is required. From the RFSP studies, this level of fuel enrichment will provide an operating period of 370 days between refueling. Relatively high axial power peaking is observed at the beginning of cycle conditions. A main finding is that the proposed reactor power level of 2540 MWth produces unacceptably high linear element ratings. This is confirmed using the FUELPIN code. A reduction in linear element rating is suggested for consideration.
Master of Applied Science (MASc)
Advisors/Committee Members: Novog, D. R., Engineering Physics and Nuclear Engineering.
Subjects/Keywords: Reactor physics; supercritical water cooled reactor; fuel; Nuclear Engineering; Nuclear Engineering
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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to Zotero / EndNote / Reference
Manager
APA (6th Edition):
McDonald, M. H. (2011). Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/11223
Chicago Manual of Style (16th Edition):
McDonald, Michael H. “Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor.” 2011. Masters Thesis, McMaster University. Accessed February 16, 2019.
http://hdl.handle.net/11375/11223.
MLA Handbook (7th Edition):
McDonald, Michael H. “Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor.” 2011. Web. 16 Feb 2019.
Vancouver:
McDonald MH. Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor. [Internet] [Masters thesis]. McMaster University; 2011. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/11375/11223.
Council of Science Editors:
McDonald MH. Fuel and Core Physics Considerations for a Pressure Tube Supercritical Water Cooled Reactor. [Masters Thesis]. McMaster University; 2011. Available from: http://hdl.handle.net/11375/11223

University of Ontario Institute of Technology
5.
Mohapatra, Subhramanyu.
Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors.
Degree: 2016, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/740
► To avoid the computational effort associated with full-core neutron transport calculations, full-core neutronics calculations for Pressurized Heavy-Water Reactors (PHWRs) are usually performed in diffusion theory…
(more)
▼ To avoid the computational effort associated with full-core neutron transport calculations, full-core neutronics calculations for Pressurized Heavy-Water Reactors (PHWRs) are usually performed in diffusion theory using an approximate core model, whereby only two energy groups are utilized and two-group neutronic properties (i.e. macroscopic cross sections and diffusion coefficients) are homogenized in two dimensions over large sub-domains, each corresponding to a 28.6 cm x 28.6 cm lattice cell. The lattice cell is the elementary geometrical unit describing the rectangular array of fuel channels comprising the PHWR core. The use of lattice-cell homogenization introduces some computational errors. One possible way to reduce such homogenization errors is to sub-divide the lattice cell into sub-cells and perform sub-cell-level homogenization. In this study, the PHWR lattice cell is divided into 3 x 3 sub-cells. Full-cell-averaged, as well as sub-cell-averaged two-group cross-sections, are generated for subsequent use in an equivalent two group two-dimensional diffusion model. Cross sections with Superhomogenization (SPH) [Hebert, 2009] factors are also utilised in an attempt to improve accuracy. The effect of using different homogenization models (full cell, partial cell, partial-cell with SPH-corrected cross sections) is tested on a two-dimensional partial-core model consisting of 3 x 3 lattice cells (bundles). Results from reference transport model with detailed geometry 69-group are compared with cell-homogenized two-group diffusion results obtained using full-cell homogenization and sub-cell homogenization with and without SPH correction factors. The application of sub-cell homogenization, as well as the use of SPH correction factors, is found to have only a minimal effect on computational accuracy.
Advisors/Committee Members: Nichita, Eleodor.
Subjects/Keywords: Applied reactor physics; Superhomogenization; PHWR; SPH factors
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mohapatra, S. (2016). Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/740
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mohapatra, Subhramanyu. “Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors.” 2016. Thesis, University of Ontario Institute of Technology. Accessed February 16, 2019.
http://hdl.handle.net/10155/740.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mohapatra, Subhramanyu. “Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors.” 2016. Web. 16 Feb 2019.
Vancouver:
Mohapatra S. Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors. [Internet] [Thesis]. University of Ontario Institute of Technology; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/10155/740.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mohapatra S. Investigation of sub-cell homogenization for PHWR lattice cells using superhomogenization factors. [Thesis]. University of Ontario Institute of Technology; 2016. Available from: http://hdl.handle.net/10155/740
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Texas A&M University
6.
Kitcher, Evans Damenortey.
Xenon Induced Power Oscillations in a Generic Small Modular Reactor.
Degree: 2016, Texas A&M University
URL: http://hdl.handle.net/1969.1/157767
► As world demand for energy continues to grow at unprecedented rates, the world energy portfolio of the future will inevitably include a nuclear energy contribution.…
(more)
▼ As world demand for energy continues to grow at unprecedented rates, the world energy portfolio of the future will inevitably include a nuclear energy contribution. It has been suggested that the Small Modular
Reactor (SMR) could play a significant role in the spread of civilian nuclear technology to nations previously without nuclear energy. As part of the design process, the SMR design must be assessed for the threat to operations posed by xenon-induced power oscillations.
In this research, a generic SMR design was analyzed with respect to just such a threat. In order to do so, a multi-
physics coupling routine was developed with MCNP/MCNPX as the neutronics solver. Thermal hydraulic assessments were performed using a single channel analysis tool developed in Python. Fuel and coolant temperature profiles were implemented in the form of temperature dependent fuel cross sections generated using the SIGACE code and
reactor core coolant densities.
The Power Axial Offset (PAO) and Xenon Axial Offset (XAO) parameters were chosen to quantify any oscillatory behavior observed. The methodology was benchmarked against results from literature of startup tests performed at a four-loop PWR in Korea. The developed benchmark model replicated the pertinent features of the
reactor within ten percent of the literature values. The results of the benchmark demonstrated that the developed methodology captured the desired phenomena accurately.
Subsequently, a high fidelity SMR core model was developed and assessed. Results of the analysis revealed an inherently stable SMR design at beginning of core life and end of core life under full-power and half-power conditions.
The effect of axial discretization, stochastic noise and convergence of the Monte Carlo tallies in the calculations of the PAO and XAO parameters was investigated. All were found to be quite small and the inherently stable nature of the core design with respect to xenon-induced power oscillations was confirmed.
Finally, a preliminary investigation into excess reactivity control options for the SMR design was conducted confirming the generally held notion that existing PWR control mechanisms can be used in iPWR SMRs with similar effectiveness. With the desire to operate the SMR under the boron free coolant condition, erbium oxide fuel integral burnable absorber rods were identified as a possible means to retain the dispersed absorber effect of soluble boron in the
reactor coolant in replacement.
Advisors/Committee Members: Chirayath, Sunil S (advisor), Charlton, William S (committee member), Poston, John W (committee member), Bangerth, Wolfgang (committee member).
Subjects/Keywords: Xenon Oscillations; Small Modular Reactor; Multi-physics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kitcher, E. D. (2016). Xenon Induced Power Oscillations in a Generic Small Modular Reactor. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157767
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kitcher, Evans Damenortey. “Xenon Induced Power Oscillations in a Generic Small Modular Reactor.” 2016. Thesis, Texas A&M University. Accessed February 16, 2019.
http://hdl.handle.net/1969.1/157767.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kitcher, Evans Damenortey. “Xenon Induced Power Oscillations in a Generic Small Modular Reactor.” 2016. Web. 16 Feb 2019.
Vancouver:
Kitcher ED. Xenon Induced Power Oscillations in a Generic Small Modular Reactor. [Internet] [Thesis]. Texas A&M University; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1969.1/157767.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kitcher ED. Xenon Induced Power Oscillations in a Generic Small Modular Reactor. [Thesis]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/157767
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Colorado
7.
Vasiliou, AnGayle Konstance.
Thermochemical Conversion of Biomass: A Molecular Viewpoint.
Degree: PhD, Chemistry & Biochemistry, 2011, University of Colorado
URL: http://scholar.colorado.edu/chem_gradetds/53
► This dissertation describes experiments performed to study the thermal decomposition of biomass from a molecular viewpoint. The structure of biomass consists of three major…
(more)
▼ This dissertation describes experiments performed to study the thermal decomposition of biomass from a molecular viewpoint. The structure of biomass consists of three major parts: cellulose, hemicellulose and lignin. Thermochemical conversion of biomass, specifically pyrolysis and gasification, yields a complex mixture of light gases, condensable vapors and aromatic tars. The goal for the gasification of biomass is to maximize the production of syngas (CO and H2 ) and minimize the production of aromatic tars. This thesis provides thermochemical information particularly related to cellulose decomposition.
The current technology for the conversion of biomass to biofuels is hindered by the lack of fundamental knowledge concerning detailed mechanisms and kinetic parameters that govern the process. In order to approach this problem, this work provides such information for furan, furfural, acetaldehyde and propionaldehyde, known intermediates in the pyrolysis of cellulose.
The thermal decomposition of the aforementioned biomass molecules was formed in a microtubular
reactor with pressures of 75-100 torr and up to temperatures of 1700 K corresponding to residence times of roughly 30-100 μs in the heated
reactor. The biomass molecules were entrained in the carrier gases He or Ar and passed through the
reactor. The thermal decomposition of the molecules occurs during transit through the heated
reactor and products are cooled upon expansion into a vacuum chamber. The pyrolysis product beam was interrogated by three unique schemes: Photoionization Time of Flight Mass Spectroscopy (PIMS) using 10.5 eV light, Matrix Isolation Infrared (IR) Spectroscopy and PIMS using tunable iv vacuum ultraviolet (VUV) radiation at the chemical dynamics beamline of the Advanced Light Source located at Lawrence Berkley National Laboratory in Berkley, CA. Unlike previous studies of biomass decomposition, these experiments were able to identify the initial pyrolysis products.
The first half of this thesis will deal with the thermal decomposition pathways and kinetics of furan and furfural. Earlier G2(MP2) electronic structure calculations predicted that furan will thermally decompose to acetylene, ketene, carbon monoxide, and propyne at lower temperatures. At higher temperatures, these calculations forecast that propargyl radical could result. We see all these products as well as the formation of aromatic hydrocarbons at higher concentrations. This is the first study to show radicals present in biomass decomposition. Thermal decomposition of furfural generates furan and thus follows the same mechanistic pathways as described above.
The second half of this manuscript details the thermal decomposition of acetaldehyde and three isotopologues CH3CDO, CD3CHO and CD3CDO as well as benzaldehyde. As thermal decomposition products of CH3CHO, we have identified CH3 (PIMS), CO (IR, PIMS), H (PIMS), H2 (PIMS), CH2CO (IR, PIMS), CH2=CHOH (IR, PIMS) and HCCH (IR, PIMS). The mechanism for decomposition of benzaldehyde is analogous to…
Advisors/Committee Members: Gayfree Barney Ellison, Veronica Bierbaum, John Daily.
Subjects/Keywords: biomass; decomposition; reactor; thermal; Physical Chemistry; Physics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
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Manager
APA (6th Edition):
Vasiliou, A. K. (2011). Thermochemical Conversion of Biomass: A Molecular Viewpoint. (Doctoral Dissertation). University of Colorado. Retrieved from http://scholar.colorado.edu/chem_gradetds/53
Chicago Manual of Style (16th Edition):
Vasiliou, AnGayle Konstance. “Thermochemical Conversion of Biomass: A Molecular Viewpoint.” 2011. Doctoral Dissertation, University of Colorado. Accessed February 16, 2019.
http://scholar.colorado.edu/chem_gradetds/53.
MLA Handbook (7th Edition):
Vasiliou, AnGayle Konstance. “Thermochemical Conversion of Biomass: A Molecular Viewpoint.” 2011. Web. 16 Feb 2019.
Vancouver:
Vasiliou AK. Thermochemical Conversion of Biomass: A Molecular Viewpoint. [Internet] [Doctoral dissertation]. University of Colorado; 2011. [cited 2019 Feb 16].
Available from: http://scholar.colorado.edu/chem_gradetds/53.
Council of Science Editors:
Vasiliou AK. Thermochemical Conversion of Biomass: A Molecular Viewpoint. [Doctoral Dissertation]. University of Colorado; 2011. Available from: http://scholar.colorado.edu/chem_gradetds/53

Georgia Tech
8.
Remley, Kyle E.
Development of methods for high performance computing applications of the deterministic stage of comet calculations.
Degree: PhD, Mechanical Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/58610
► The Coarse Mesh Radiation Transport (COMET) method is a reactor physics method and code that has been used to solve whole core reactor eigenvalue and…
(more)
▼ The Coarse Mesh Radiation Transport (COMET) method is a
reactor physics method and code that has been used to solve whole core
reactor eigenvalue and flux distribution problems. A strength of the method is its formidable accuracy and computational efficiency. COMET solutions are computed to Monte Carlo accuracy on a single processor in a runtime that is several orders of magnitude faster than stochastic calculations. However, with the growing ubiquity of both shared and distributed memory parallel machines and the desire to extend the method to allow for coupling to multiphysics and on-the-fly response generation, serial implementations of COMET calculations will become less desirable. It is under this motivation that an implementation for a parallel execution of deterministic COMET calculations has been developed. COMET involves inner and outer iterations; inner iterations involve local calculations that can be carried out independently, making the algorithm amenable to parallelization. However, considerations for decomposing a problem and the distribution of data must be made. To allow for efficient parallel implementation of a distributed algorithm, changes to response data access and sweep order are made, along with considerations for communications between processors. The parallel code is implemented on several variants of the C5G7 benchmark problem to assess the scalability of the algorithm, and it is found that problems with larger numbers of coarse meshes increase the scalability of the code, which is an encouraging result. The code is further tested for full core
reactor problems, where extremely efficient wall clock times (on the order of minutes) for solutions are achieved. Finally, application of the parallel code to novel implementations of COMET (e.g., problems with high flux expansions) is discussed.
Advisors/Committee Members: Rahnema, Farzad (advisor), Petrovic, Bojan (committee member), Zhang, Dingkang (committee member), Morley, Tom (committee member), Haghighat, Alireza (committee member).
Subjects/Keywords: Coarse mesh transport; Parallel computing; Reactor physics
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APA (6th Edition):
Remley, K. E. (2016). Development of methods for high performance computing applications of the deterministic stage of comet calculations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58610
Chicago Manual of Style (16th Edition):
Remley, Kyle E. “Development of methods for high performance computing applications of the deterministic stage of comet calculations.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 16, 2019.
http://hdl.handle.net/1853/58610.
MLA Handbook (7th Edition):
Remley, Kyle E. “Development of methods for high performance computing applications of the deterministic stage of comet calculations.” 2016. Web. 16 Feb 2019.
Vancouver:
Remley KE. Development of methods for high performance computing applications of the deterministic stage of comet calculations. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1853/58610.
Council of Science Editors:
Remley KE. Development of methods for high performance computing applications of the deterministic stage of comet calculations. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58610

Oregon State University
9.
Peguero, Lara M.
Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor.
Degree: MS, Nuclear Engineering, 2016, Oregon State University
URL: http://hdl.handle.net/1957/59812
► Interest in increased fuel supply stability has driven an investigation into possible alternate fuel for use in the WWR-SM research reactor at the Institute of…
(more)
▼ Interest in increased fuel supply stability has driven an investigation into possible alternate fuel for use in the WWR-SM research
reactor at the Institute of Nuclear
Physics in Uzbekistan. The WWR-SM is a high-power, pool-type research
reactor currently utilizing IRT-4M fuel made by a single Russian supplier. A candidate for new fuel is the Korean-made High-flux Advanced Neutron Application
Reactor (HANARO) fuel rod, which maintains the low 19.75% enrichment of the current fuel but has a different configuration.
To examine the safety and operational parameters of the HANARO fuel rods in the WWR-SM core, the Monte Carlo N-Particle transport code is used to model the neutronics and the PLTEMP code from Argonne National Lab is used to compute thermal-hydraulic parameters. While the core structure will remain unchanged, the plate-type IRT-3M assembly models will be replaced with models of assemblies using HANARO fuel rods that preserve the outer dimensions and central flux trap for irradiation of samples.
Three candidate assemblies are assessed for neutronic viability. Two contain the standard HANARO fuel rods with different pitches between 16 fuel rods arranged within the space between basic structures of the IRT assemblies. The other assembly contains a modified HANARO fuel rod with a reduced fuel meat radius; this smaller rod allows for more fuel rods in the assembly, thus increasing the heat transfer area.
Neutronic results indicate viability of one of the standard HANARO fuel rod assemblies. The modified HANARO fuel rod assemblies do not maintain sufficient excess reactivity when placed in the core configuration to operate at a critical state, making standard WWR-SM operations impossible. Whearas the undermoderated standard HANARO fuel rod assemblies have a significantly positive temperature coefficient of reactivity making them unsafe in positive temperature transient conditions.
When 24 optimal pitch assemblies are in the WWR-SM core model, the core has sufficient excess reactivity to maintain a critical state and produces flux levels within the target range of 10¹² to 3 x 10¹⁴ n cm⁻² s⁻¹. Power distributions and depletion analysis suggest that the cycle length for this core would be at least comparable to the 24 day cycle for IRT-3M fuel assemblies, if not better. However, this core configuration has too much excess reactivity and does not meet the operational shutdown margin requirement. Minor modifications could be made to the core configuration to meet the shutdown margin but are not explored here.
Thermal-hydraulic analysis of the optimal pitch HANARO fuel rod shows that low flow rates and the existing pressure drop across the WWR-SM core would result in nucleate boiling along the length of the fuel rod, though flow remains stable. In addition, the maximum temperature in the fuel in some simulations reaches temperatures within 20% of the operational design maximum of 350 °C. Temperature results from the PLTEMP code agree well with hand calculations with an average relative difference of 7%.
Advisors/Committee Members: Palmer, Todd S. (advisor), Stetz, Albert (committee member).
Subjects/Keywords: Reactor physics; Light water reactors – Uzbekistan
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Peguero, L. M. (2016). Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/59812
Chicago Manual of Style (16th Edition):
Peguero, Lara M. “Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor.” 2016. Masters Thesis, Oregon State University. Accessed February 16, 2019.
http://hdl.handle.net/1957/59812.
MLA Handbook (7th Edition):
Peguero, Lara M. “Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor.” 2016. Web. 16 Feb 2019.
Vancouver:
Peguero LM. Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor. [Internet] [Masters thesis]. Oregon State University; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1957/59812.
Council of Science Editors:
Peguero LM. Feasibility Study of Using HANARO Fuel Rods in WWR-SM Reactor. [Masters Thesis]. Oregon State University; 2016. Available from: http://hdl.handle.net/1957/59812

University of Ontario Institute of Technology
10.
Ferguson, Thomas.
Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model.
Degree: 2018, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/940
► Superhomogenization (SPH) has gained interest in the industry as a possible method to overcome the inherent limitations of standard homogenization (SH) for full nuclearreactor-core neutronics…
(more)
▼ Superhomogenization (SPH) has gained interest in the industry as a possible method to overcome the inherent limitations of standard homogenization (SH) for full nuclearreactor-core neutronics calculations because its implementation does not require any changes to existing computer codes. Previous work found that single-cell SPH applied to Pressurized Heavy Water Reactors (PHWR) yields virtually no improvement compared to single-cell standard homogenization. This work attempts to improve those results by accounting for neutron leakage across cell boundaries by performing SPH-based homogenization using a 3??3 multi-cell model. The method is evaluated using a 5??5 lattice-cell model and comparing results for single-cell SH, multi-cell SH, single-cell SPH and multi-cell SPH. Results show that multi-cell SPH produces better results than single-cell SPH and multi-cell SH produces better results than single-cell SH. However, multi-cell SPH offers no improvement compared to multi-cell SH, just as single-cell SPH offers no improvement over single-cell SH.
Advisors/Committee Members: Nichita, Eleodor.
Subjects/Keywords: Applied reactor physics; Superhomogenization; SPH factors; PHWR
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ferguson, T. (2018). Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/940
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ferguson, Thomas. “Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model.” 2018. Thesis, University of Ontario Institute of Technology. Accessed February 16, 2019.
http://hdl.handle.net/10155/940.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ferguson, Thomas. “Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model.” 2018. Web. 16 Feb 2019.
Vancouver:
Ferguson T. Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model. [Internet] [Thesis]. University of Ontario Institute of Technology; 2018. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/10155/940.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ferguson T. Investigation of a SPH-based sub-cell homogenization for PHWR using a multi-cell model. [Thesis]. University of Ontario Institute of Technology; 2018. Available from: http://hdl.handle.net/10155/940
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Cambridge
11.
Lindley, Benjamin A.
The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel.
Degree: PhD, 2015, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/247162
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642470
► Light water reactors (LWRs) are the world’s dominant nuclear reactor system. Uranium (U)-fuelled LWRs produce long-lived transuranic (TRU) isotopes. TRUs can be recycled in LWRs…
(more)
▼ Light water reactors (LWRs) are the world’s dominant nuclear reactor system. Uranium (U)-fuelled LWRs produce long-lived transuranic (TRU) isotopes. TRUs can be recycled in LWRs or fast reactors. The thermal neutron spectrum in LWRs is less suitable for burning TRUs as this causes a build-up of TRU isotopes with low fission probability. This increases the fissile feed requirements, which tends to result in a positive void coefficient (VC) and hence the reactor is unsafe to operate. Use of reduced-moderation LWRs can improve TRU transmutation performance, but the VC is still severely limiting for these designs. Reduced-moderation pressurized water reactors (RMPWRs) and boiling water reactors (RBWRs) are considered in this study. Using thorium (Th) instead of U as the fertile fuel component can greatly improve the VC. However, Th-based transmutation is a much less developed technology than U-based transmutation. In this thesis, the feasibility and fuel cycle performance of full TRU recycle in Th-fuelled RMPWRs and RBWRs are evaluated. Neutronic performance is greatly improved by spatial separation of TRU and 233-6U, primarily implemented here using heterogeneous RMPWR and RBWR assembly designs. In a RMPWR, the water to fuel ratio must be reduced to around 50% of the normal value to allow full actinide recycle. If implemented by retrofitting an existing PWR, steady-state thermal-hydraulic constraints can still be satisfied. However, in a large break loss-of-coolant accident, the emergency core cooling system may not be able to provide water to the core quickly enough to prevent fuel cladding failure. A discharge burn-up of ~40 GWd/t is possible in RMPWRs. Reactivity control is a challenge due to the reduced worth of neutron absorbers in the hard neutron spectrum, and their detrimental effect on the VC, especially when diluted, as for soluble boron. Control rods are instead used to control the core. It appears possible to achieve adequate power peaking, shutdown margin and rod-ejection accident response. In RBWRs, it appears neutronically feasible to achieve very high burn-ups (~120 GWd/t) but the maximum achievable incineration rate is less than in RMPWRs. The reprocessing and fuel fabrication requirements of RBWRs are less than RMPWRs but more than fast reactors. A two-stage TRU burning cycle, where the first stage is Th-Pu MOX in a conventional PWR feeding a second stage continuous burn in a RBWR, is technically reasonable. It is possible to limit the core area to that of an ABWR with acceptable thermal-hydraulic performance. In this case, it appears that RBWRs are of similar cost to inert matrix incineration in LWRs, and lower cost than RMPWRs and Th- and U-based fast reactor recycle schemes.
Subjects/Keywords: 539.7; Thorium; Light Water Reactor; Plutonium; Transuranic; Reduced-moderation; Nuclear fuel cycle; Reactor physics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lindley, B. A. (2015). The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/247162 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642470
Chicago Manual of Style (16th Edition):
Lindley, Benjamin A. “The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel.” 2015. Doctoral Dissertation, University of Cambridge. Accessed February 16, 2019.
https://www.repository.cam.ac.uk/handle/1810/247162 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642470.
MLA Handbook (7th Edition):
Lindley, Benjamin A. “The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel.” 2015. Web. 16 Feb 2019.
Vancouver:
Lindley BA. The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel. [Internet] [Doctoral dissertation]. University of Cambridge; 2015. [cited 2019 Feb 16].
Available from: https://www.repository.cam.ac.uk/handle/1810/247162 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642470.
Council of Science Editors:
Lindley BA. The use of reduced-moderation light water reactors for transuranic isotope burning in thorium fuel. [Doctoral Dissertation]. University of Cambridge; 2015. Available from: https://www.repository.cam.ac.uk/handle/1810/247162 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642470
12.
Berggren, Alexander.
Development of a Mobile Reactor for Large Scale Water Treatment.
Degree: Physics, 2019, Umeå University
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155584
► Water pollution is one of many environmental problems that currently exists and inadequate treatment of industrial wastewater is contributing to further pollution. SpinChem AB's…
(more)
▼ Water pollution is one of many environmental problems that currently exists and inadequate treatment of industrial wastewater is contributing to further pollution. SpinChem AB's Rotating Bed Reactor (RBR) technology offers the possibility of water treatment by carrying out reactions between a solution and a solid phase. To move further in the field of large scale water treatment, SpinChem AB developed a prototype of a mobile reactor, i.e. a raft, carrying the RBR technology. The prototype proved that a mobile reactor can greatly reduce the process time for larger water volumes compared to a stationary RBR. The aim of this thesis is to develop the next version of the mobile reactor, with increased operational stability and autonomous driving (autopilot) as main goals. This work covers all parts in the development of the new mobile reactor which involves design, simulation, construction, electronics, software implementations and testing. The presented mobile reactor is a twin hull surface vehicle with the possibility of using two RBRs for water treatment. The steering is based on differential motor thrust and the autonomous driving was achieved using sensor data from a GPS, magnetometer and accelerometer, together with a proportional-integral-derivative (PID) type control system. The autopilot was put to the test on two different travel routes with a P and PI controller. The mobile reactor successfully followed the given routes, thus verifying that the developed mobile reactor can be used for future autonomous large scale water treatment.
Subjects/Keywords: Water treatment; Mobile reactor; Autopilot; Rotating Bed Reactor; Other Physics Topics; Annan fysik
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Berggren, A. (2019). Development of a Mobile Reactor for Large Scale Water Treatment. (Thesis). Umeå University. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155584
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Berggren, Alexander. “Development of a Mobile Reactor for Large Scale Water Treatment.” 2019. Thesis, Umeå University. Accessed February 16, 2019.
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Berggren, Alexander. “Development of a Mobile Reactor for Large Scale Water Treatment.” 2019. Web. 16 Feb 2019.
Vancouver:
Berggren A. Development of a Mobile Reactor for Large Scale Water Treatment. [Internet] [Thesis]. Umeå University; 2019. [cited 2019 Feb 16].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155584.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Berggren A. Development of a Mobile Reactor for Large Scale Water Treatment. [Thesis]. Umeå University; 2019. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-155584
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

KTH
13.
Luszczek, Karol.
Validation and Benchmarking of Westinghouse BWR lattice physics methods.
Degree: Reactor Technology, 2015, KTH
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180563
► A lattice physics code is a vital tool, forming a base of reactor coreanalysis. It enables the neutronic properties of the fuel assembly to…
(more)
▼ A lattice physics code is a vital tool, forming a base of reactor coreanalysis. It enables the neutronic properties of the fuel assembly to becalculated and generates a proper set of data to be used by a 3-D full coresimulator. Due to advancement and complexity of modern Boiling WaterReactor assembly designs, a new deterministic lattice physics codeis being developed at Westinghouse Sweden AB, namely PHOENIX5.Each time a new code is written, its methodology of solving the neutrontransport equation, has to be validated to make sure it providesreliable output. In a wake of preparation for PHOENIX5 release andconsecutive validation efforts, a set of reference Monte Carlo calculationswas prepared, using the code Serpent. A depletion calculation with achosen type of branch cases was conducted. Methods implemented inPHOENIX5 are based on the Current Coupling Collision Probabilitymethod used in older versions of the code HELIOS. Therefore, a comparisonbetween reference Monte Carlo simulations and HELIOS 1.8.1is made, in order to discover problems inherent to the said method ofsolving the neutron transport equation. A special care should be givenduring PHOENIX5 validation, to issues highlighted in this work.Discrepancies in results of Serpent and HELIOS are attributed mostlyto disparities in the basic nuclear data used by the codes, as well as arange of approximations and corrections adopted by the deterministiccode.Serpent and HELIOS showed a good agreement in a typical voidrange (up to 90 % void) and ‘less’ challenging branches (coolant void,fuel temperature and spacer grid branches). More significant discrepanciesappeared for extreme cases with a very high void and control rodpresence (k1 differences as high as 1000 pcm) and rather pronouncedconcentrations of the natural boron dissolved in coolant (absolute differencesroughly at a level of 900 pcm). The issues do not seem to stemsolely from discrepancies in the nuclear data libraries used by Serpentand HELIOS.Moreover, a coolant void bias was consistently found in the resultsof branch calculation at changing coolant void. This confirms the analogousphenomenon found in previous studies of the CCCP based deterministiccodes. It most probably stems from the assumptions used bythe method while tackling the neutron transport equation, such as theflat source approximation, the isotropic scattering assumption and thetransport correction. An alternative transport correction approximationis proposed to alleviate this issue.
Subjects/Keywords: Serpent; HELIOS; lattice physics; benchmarking; Monte Carlo; neutronics; reactor physics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Luszczek, K. (2015). Validation and Benchmarking of Westinghouse BWR lattice physics methods. (Thesis). KTH. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180563
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Luszczek, Karol. “Validation and Benchmarking of Westinghouse BWR lattice physics methods.” 2015. Thesis, KTH. Accessed February 16, 2019.
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180563.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Luszczek, Karol. “Validation and Benchmarking of Westinghouse BWR lattice physics methods.” 2015. Web. 16 Feb 2019.
Vancouver:
Luszczek K. Validation and Benchmarking of Westinghouse BWR lattice physics methods. [Internet] [Thesis]. KTH; 2015. [cited 2019 Feb 16].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180563.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Luszczek K. Validation and Benchmarking of Westinghouse BWR lattice physics methods. [Thesis]. KTH; 2015. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180563
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Ontario Institute of Technology
14.
Carisse, Katarzyna.
Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR.
Degree: 2014, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/458
► The neutron flux throughout a reactor core should be calculated, ideally, by solving the neutron transport equation for a highly detailed geometric model of the…
(more)
▼ The neutron flux throughout a
reactor core should be calculated, ideally, by solving the neutron transport equation for a highly detailed geometric model of the core. Since this is computationally impractical, approximate node-homogenized models have historically been used whereby neutronic properties are averaged over cartesian parallelepipedic regions called nodes. This process is referred to as homogenization. The simplest homogenization procedure is known as standard homogenization. Standard homogenization calculates node-homogenized cross sections as flux-weighted averages over the volume of each node. It uses an approximate spatial flux distribution obtained from single-node detailed-geometry calculations that approximate the node-boundary conditions to be reflective. While standard homogenization has been successfully used for CANDU reactors, there exist more advanced homogenization methods such as Generalized Equivalence Theory (GET). GET improves accuracy by allowing the neutron flux in the node-homogenized model to be discontinuous at node boundaries through the use of discontinuity factors. Node-averaged cross sections and discontinuity factors can be obtained from single-node calculations using reflective boundary conditions. To further improve accuracy, non-reflective boundary conditions that approximate the real node-boundary conditions can be used; a process known as leakage correction.
This work explores the use of GET with leakage-corrected cross sections and discontinuity factors for the next-generation PT-SCWR flux calculations. Results show that using GET in conjunction with leakage corrections yields substantial improvements in accuracy over standard homogenization and should be given serious consideration as a method for performing neutronic calculations for PT-SCWR cores.
Advisors/Committee Members: Nichita, Eleodor.
Subjects/Keywords: Applied reactor physics; Advanced homogenization; CANDU; PT-SCWR
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Carisse, K. (2014). Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/458
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Carisse, Katarzyna. “Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR.” 2014. Thesis, University of Ontario Institute of Technology. Accessed February 16, 2019.
http://hdl.handle.net/10155/458.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Carisse, Katarzyna. “Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR.” 2014. Web. 16 Feb 2019.
Vancouver:
Carisse K. Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR. [Internet] [Thesis]. University of Ontario Institute of Technology; 2014. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/10155/458.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Carisse K. Leakage-corrected discontinuity factors for a second-generation Th-Pu pressure-tube SCWR. [Thesis]. University of Ontario Institute of Technology; 2014. Available from: http://hdl.handle.net/10155/458
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
15.
Domingos, Douglas Borges.
Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB.
Degree: PhD, Tecnologia Nuclear - Reatores, 2014, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-17122014-133601/
;
► Neste trabalho foi realizado uma comparação entre três tipos de alvos (UAl2-Al, U-Ni cilíndrico e U-Ni placa) para a produção de 99Mo por fissão do…
(more)
▼ Neste trabalho foi realizado uma comparação entre três tipos de alvos (UAl2-Al, U-Ni cilíndrico e U-Ni placa) para a produção de 99Mo por fissão do 235U. Para isso foram desenvolvidas análises neutrônicas e termo-hidráulicas. Também foram realizados experimentos para se validar as metodologias de cálculo termo-hidráulica e neutrônica utilizadas neste trabalho. Para os cálculos neutrônicos foram utilizados os programas NJOY99.0, AMPX-II e HAMMERTECHNION, para geração das seções de choque, e os programas SCALE 6.0 e CITATION para os cálculos tridimensionais dos núcleos, queima do combustível e produção de 99Mo. Para os cálculos termo-hidráulicos foram utilizados os programas MTRCRIEAR1 e ANSYS CFX para calcular as variáveis térmicas e hidráulicas dos dispositivos de irradiação e compará-las a limites e critérios de projeto estabelecidos. Primeiro foram realizadas análises neutrônicas e termo-hidráulicas para o reator IEA-R1 com os alvos de UAl2-Al (10 miniplacas). As análises demonstraram que a atividade total obtida para o 99Mo nas miniplacas não atende à demanda dos hospitais brasileiros (450 Ci/semana) e que nenhum limite de projeto termo-hidráulico é ultrapassado. Em seguida foram realizados os mesmos cálculos para os três tipos de alvo no Reator Multipropósito Brasileiro (RMB). As análises neutrônicas demonstraram que os três alvos podem atender à demanda dos hospitais brasileiros. As análises termo-hidráulicos demonstram que será necessário uma velocidade mínima no dispositivo de irradiação de 7 m/s para o UAl2, de 8 m/s para o alvo de U-Ni cilíndrico e de 9 m/s para o alvo de U-Ni placa para que nenhum limite de projeto seja ultrapassado. Foram realizados experimentos em uma bancada de aferição de vazão para se validar a metodologia de cálculo termo-hidráulico. Os experimentos realizados para se validar os cálculos neutrônicos foram feitos no reator IPEN/MB-01. Todos os experimentos foram simulados com as metodologias acima descritas e os resultados comparados entre si. Os resultados das simulações apresentaram boa concordância com os resultados experimentais.
In this work neutronic and thermal-hydraulic analyses were made to compare three types of targets (UAl2-Al, U-Ni cylindrical and U-Ni plate) used for the production of 99Mo by fission of 235U. Some experiments were conducted to validate the neutronic and thermal-hydraulics methodologies used in this work. For the neutronic calculations the computational programs NJOY99.0, AMPX-II and HAMMERTECHNION were used to generate the cross sections. SCALE 6.0 and CITATION computational programs were used for three-dimensional calculations of the reactor cores, fuel burning and the production of 99Mo. The computational programs MTRCR-IEAR1 and ANSYS CFX were used to calculate the thermal and hydraulic parameters of the irradiation devices and for comparing them to limits and design criteria. First were performed neutronic and thermal-hydraulic analyzes for the reactor IEA-R1 with the targets of UAl2-Al (10 miniplates). Analyses have shown that the total activity…
Advisors/Committee Members: Santos, Adimir dos, Silva, Antonio Teixeira e.
Subjects/Keywords: física de reatores; radiofármacos; radiopharmaceuticals; reactor physics; termo-hidráulica; thermo-hydraulic
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APA (6th Edition):
Domingos, D. B. (2014). Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/85/85133/tde-17122014-133601/ ;
Chicago Manual of Style (16th Edition):
Domingos, Douglas Borges. “Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB.” 2014. Doctoral Dissertation, University of São Paulo. Accessed February 16, 2019.
http://www.teses.usp.br/teses/disponiveis/85/85133/tde-17122014-133601/ ;.
MLA Handbook (7th Edition):
Domingos, Douglas Borges. “Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB.” 2014. Web. 16 Feb 2019.
Vancouver:
Domingos DB. Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB. [Internet] [Doctoral dissertation]. University of São Paulo; 2014. [cited 2019 Feb 16].
Available from: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-17122014-133601/ ;.
Council of Science Editors:
Domingos DB. Análises neutrônica e termo-hidráulica de dispositivos para irradiação de alvos tipo LEU de UAlx-Al e U-Ni para produção de Mo-99 nos reatores IEA-R1 e RMB. [Doctoral Dissertation]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-17122014-133601/ ;

The Ohio State University
16.
Abejon Orzaez, Jorge.
Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor.
Degree: MS, Nuclear Engineering, 2009, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1238045558
► The objective of this research is to, based on the original design for the Pebble Bed Advanced High Temperature Reactor (PB-AHTR), develop an MCNPX model…
(more)
▼ The objective of this research is to, based on the
original design for the Pebble Bed Advanced High Temperature
Reactor (PB-AHTR), develop an MCNPX model of the
reactor core with
the objective to attain criticality and to breed new fuel. A brief
but complete description of a first approach to the PB-AHTR will be
provided and a MCNPX model will be run in order to ascertain the
difficulties of that configuration. On the second part, a
modification of the original model will be evaluated and compared
in order to resolve the difficulties encountered in the original
design. Finally, in an effort to optimize the design, an
evolutionary approach will be analyzed, based on the previous
model, and conclusions will be attained
Advisors/Committee Members: Blue, Thomas (Committee Chair), Sun, Xiaodong (Committee Co-Chair).
Subjects/Keywords: Engineering; Nuclear Physics; Neutronics; advanced high temperature reactor; criticality
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APA (6th Edition):
Abejon Orzaez, J. (2009). Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor. (Masters Thesis). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1238045558
Chicago Manual of Style (16th Edition):
Abejon Orzaez, Jorge. “Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor.” 2009. Masters Thesis, The Ohio State University. Accessed February 16, 2019.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1238045558.
MLA Handbook (7th Edition):
Abejon Orzaez, Jorge. “Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor.” 2009. Web. 16 Feb 2019.
Vancouver:
Abejon Orzaez J. Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor. [Internet] [Masters thesis]. The Ohio State University; 2009. [cited 2019 Feb 16].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1238045558.
Council of Science Editors:
Abejon Orzaez J. Neutronics analysis of a modified Pebble Bed Advanced High
Temperature Reactor. [Masters Thesis]. The Ohio State University; 2009. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1238045558

Georgia Tech
17.
Keller, Steven Ede.
Flux-limited Diffusion Coefficient Applied to Reactor Analysis.
Degree: PhD, Nuclear Engineering, 2007, Georgia Tech
URL: http://hdl.handle.net/1853/16126
► A new definition of the diffusion coefficient for use in reactor physics calculations is evaluated in this thesis. It is based on naturally flux-limited diffusion…
(more)
▼ A new definition of the diffusion coefficient for use in
reactor physics calculations is evaluated in this thesis. It is based on naturally flux-limited diffusion theory (FDT), sometimes referred to as Levermore-Pomraning diffusion theory. Another diffusion coefficient more loosely based on FDT is also evaluated in this thesis. Flux-limited diffusion theory adheres to the physical principle of flux-limiting, which is that the magnitude of neutron current is not allowed to exceed the scalar flux. Because the diffusion coefficients currently used in the nuclear industry are not flux-limited they may violate this principle in regions of large spatial gradients, and because they encompass other assumptions, they are only accurate when used in the types of calculations for which they were intended.
The evaluations were performed using fine-mesh diffusion theory. They are in one spatial dimension and in 47, 4, and 2 energy groups, and were compared against a transport theory benchmark using equivalent energy structures and spatial discretization.
The results show that the flux-limited diffusion coefficient (FD) outperforms the standard diffusion coefficient in calculations of single assemblies with vacuum boundaries, according to flux- and eigenvalue-errors. In single assemblies with reflective boundary conditions, the FD yielded smaller improvements, and tended to improve only the fast-group results. The results also computationally confirm that the FD adheres to flux-limiting, while the standard diffusion coefficient does not.
Advisors/Committee Members: Dr. Farzad Rahnema (Committee Chair), Dr. Daniel W. Tedder (Committee Member), Dr. Nolan E. Hertel (Committee Member), Dr. Thomas D. Morley (Committee Member), Dr. Weston M. Stacey, Jr. (Committee Member).
Subjects/Keywords: Transport cross section; Reactor physics
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APA ·
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MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Keller, S. E. (2007). Flux-limited Diffusion Coefficient Applied to Reactor Analysis. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/16126
Chicago Manual of Style (16th Edition):
Keller, Steven Ede. “Flux-limited Diffusion Coefficient Applied to Reactor Analysis.” 2007. Doctoral Dissertation, Georgia Tech. Accessed February 16, 2019.
http://hdl.handle.net/1853/16126.
MLA Handbook (7th Edition):
Keller, Steven Ede. “Flux-limited Diffusion Coefficient Applied to Reactor Analysis.” 2007. Web. 16 Feb 2019.
Vancouver:
Keller SE. Flux-limited Diffusion Coefficient Applied to Reactor Analysis. [Internet] [Doctoral dissertation]. Georgia Tech; 2007. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1853/16126.
Council of Science Editors:
Keller SE. Flux-limited Diffusion Coefficient Applied to Reactor Analysis. [Doctoral Dissertation]. Georgia Tech; 2007. Available from: http://hdl.handle.net/1853/16126

University of Manchester
18.
Black, Greg.
Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal.
Degree: Thesis (Eng.D.), 2014, University of Manchester
URL: https://www.research.manchester.ac.uk/portal/en/theses/irradiated-graphite-waste-analysis-and-modelling-of-radionuclide-production-with-a-view-to-long-term-disposal(9993a76a-15c6-4cbe-a4a3-4c0bc88c3134).html
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664547
► The University of Manchester Greg BlackThesis submitted for the degree of Doctor of EngineeringIrradiated Graphite Waste: Analysis and Modelling of Radionuclide Production with a View…
(more)
▼ The University of Manchester Greg BlackThesis submitted for the degree of Doctor of EngineeringIrradiated Graphite Waste: Analysis and Modelling of Radionuclide Production with a View to Long Term Disposal23rd June 2014The UK has predominantly used graphite moderator reactor designs in both its research and civil nuclear programmes. This material will become activated during operation and, once all reactors are shutdown, will represent a waste legacy of 96,000 tonnes [1]. The safe and effective management of this material will require a full understanding of the final radiological inventory. The activity is known to arise from impurities present in the graphite at start of life as well as from contamination products transported from other components in the reactor circuit. The process is further complicated by radiolytic oxidation which leads to considerable weightloss of the graphite components. A comprehensive modelling methodology has been developed and validated to estimate the activity of the principle radionuclides of concern, 3H, 14C, 36Cl and 60Co. This methodology involves the simulation of neutron flux using the reactor physics code WIMS, and radiation transport code MCBEND. Activation calculations have been performed using the neutron activation software FISPACT. The final methodology developed allows full consideration of all processes which may contribute to the final radiological inventory of the material. The final activity and production pathway of each radionuclide has been researched in depth, as well as operational parameters such as the effect of changes in flux, fuel burnup, graphite weightloss and irradiation time. Methods to experimentally determine the activity, and distribution of key radionuclides within irradiated graphite samples have been developed in this research using a combination of both gamma spectroscopy and autoradiography. This work has been externally validated and provides confidence in the accuracy of the final modelling predictions. This work has been undertaken as part of the EU FP7 EURATOM Project: CARBOWASTE, and was funded by the Office for Nuclear Regulation.
Subjects/Keywords: 621.48; Nuclear Graphite; Radioactive Waste Management; Reactor Physics Modelling; Gamma Spectroscopy
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Black, G. (2014). Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/irradiated-graphite-waste-analysis-and-modelling-of-radionuclide-production-with-a-view-to-long-term-disposal(9993a76a-15c6-4cbe-a4a3-4c0bc88c3134).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664547
Chicago Manual of Style (16th Edition):
Black, Greg. “Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal.” 2014. Doctoral Dissertation, University of Manchester. Accessed February 16, 2019.
https://www.research.manchester.ac.uk/portal/en/theses/irradiated-graphite-waste-analysis-and-modelling-of-radionuclide-production-with-a-view-to-long-term-disposal(9993a76a-15c6-4cbe-a4a3-4c0bc88c3134).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664547.
MLA Handbook (7th Edition):
Black, Greg. “Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal.” 2014. Web. 16 Feb 2019.
Vancouver:
Black G. Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal. [Internet] [Doctoral dissertation]. University of Manchester; 2014. [cited 2019 Feb 16].
Available from: https://www.research.manchester.ac.uk/portal/en/theses/irradiated-graphite-waste-analysis-and-modelling-of-radionuclide-production-with-a-view-to-long-term-disposal(9993a76a-15c6-4cbe-a4a3-4c0bc88c3134).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664547.
Council of Science Editors:
Black G. Irradiated graphite waste : analysis and modelling of radionuclide production with a view to long term disposal. [Doctoral Dissertation]. University of Manchester; 2014. Available from: https://www.research.manchester.ac.uk/portal/en/theses/irradiated-graphite-waste-analysis-and-modelling-of-radionuclide-production-with-a-view-to-long-term-disposal(9993a76a-15c6-4cbe-a4a3-4c0bc88c3134).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664547

Georgia Tech
19.
Kooreman, Gabriel.
Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport.
Degree: PhD, Mechanical Engineering, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/59134
► The neutron transport equation often is homogenized in order to simplify its solution procedure in some manner or another. There exist many methods for homogenizing…
(more)
▼ The neutron transport equation often is homogenized in order to simplify its solution procedure in some manner or another. There exist many methods for homogenizing the neutron transport equation with different benefits and detriments. One promising method is the Consistent Spatial Homogenization (CSH) method developed and implemented in 1-D by Yasseri and Rahnema. The method, along with its successor, the Diffusion-Transport Homogenization (DTH) method are promising for their ability to reconstruct accurate fine-mesh angular flux profiles as well as
reactor eigenvalue after a re-homogenization procedure. This work will explore the extension of both the CSH and DTH methods to higher spatial dimensionality in order to solve large-scale
reactor eigenvalue problems. The CSH and DTH methods are based around iterated re-homogenization of the neutron transport equation with an auxiliary source term which is used to correct for heterogeneity effects of a given problem. The net effect of this is that the effects of heterogeneity are relegated to a source term, and the homogenized neutron transport equation is solved instead of the heterogeneous equation. This allows for implementation of simpler acceleration techniques to improve the speed and accuracy of the homogenized problem and in multiple dimensions helps to avoid the effects of complicated
reactor geometries. The re-homogenization procedure brings the flux solution back to the heterogeneous discretization in order to generate better approximations for the homogenized cross sections, a better approximation of the auxiliary source term, and most importantly to reconstruct the full heterogeneous angular flux profile. In this work, the CSH and DTH methods are modified for increased spatial dimensionality and implemented using a 2-D SN discrete ordinates transport solver. This implementation is tested using Cartesian-mesh variants of the 2D-C5G7 benchmark problem and a 2-D full-scale boiling water
reactor (BWR) benchmark problem.
Advisors/Committee Members: Rahnema, Farzad (advisor), Petrovic, Bojan (committee member), Zhang, Dingkang (committee member), Morley, Tom (committee member), Densmore, Jeffery (committee member).
Subjects/Keywords: Neutron transport; Homogenization; Diffusion; Eigenvalue calculation; Reactor physics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kooreman, G. (2016). Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59134
Chicago Manual of Style (16th Edition):
Kooreman, Gabriel. “Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport.” 2016. Doctoral Dissertation, Georgia Tech. Accessed February 16, 2019.
http://hdl.handle.net/1853/59134.
MLA Handbook (7th Edition):
Kooreman, Gabriel. “Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport.” 2016. Web. 16 Feb 2019.
Vancouver:
Kooreman G. Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1853/59134.
Council of Science Editors:
Kooreman G. Iterative homogenization method for improving computational efficiency in solving eigenvalue problems in neutron transport. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/59134

University of Illinois – Urbana-Champaign
20.
McKenzie, George.
Modern Rossi alpha measurements.
Degree: MS, 5183, 2015, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/72834
► The Rossi-α method determines the prompt neutron decay constant in a nuclear fissioning system at or near delayed critical. Knowledge of the prompt neutron decay…
(more)
▼ The Rossi-α method determines the prompt neutron decay constant in a nuclear fissioning system at or near delayed critical. Knowledge of the prompt neutron decay constant is important for a critical system as it is a major contributor to the dynamic system behavior. The classical method for the Rossi experiment used gated circuitry to track the time when a neutron was incident upon the detector. The downside of this method is that the circuitry was complex and only one single fission chain could be measured at a time. The modern method allows many chains to be measured simultaneously by a pulse time tagging system such as the LANL custom designed List-mode module.
This thesis examines the implementation of the modern Rossi-α method on the all highly enriched uranium, HEU, Zeus experiment. Measurements are taken at several subcritical configurations, at critical in the presence of a source, and at one supercritical point. During the experiment, the List-mode module generates time tags of incoming neutron pulses. After the experiment, this list of neutron pulses is complied using custom software into a histogram. This histogram is fit using off the shelf graphing software to determine the value of α.
The subcritical measurements of α are used to extrapolate α at delayed critical. The extrapolation determined the value of α at delayed critical to be α = 89910 s-1. This value is compared to the measured value of α at delayed critical which is determined to be α = 90408.4 s-1. These values differ by 0.55% which is remarkably good agreement. This thesis also examines the expected value of α using a Monte Carlo transport code, MCNP. MCNP determined the value of α at delayed critical to be 100048 ± 0.584 s-1. This result differs by 11.3% from the extrapolated value of α determined experimentally. When compared to systems with similar neutron spectra, the measured value of α fits well in comparison to historical measurements.
Advisors/Committee Members: Kozlowski, Tomasz (advisor).
Subjects/Keywords: Reactor Physics; Rossi Alpha; Zeus Experiment; Neutron Measurements
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
McKenzie, G. (2015). Modern Rossi alpha measurements. (Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/72834
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
McKenzie, George. “Modern Rossi alpha measurements.” 2015. Thesis, University of Illinois – Urbana-Champaign. Accessed February 16, 2019.
http://hdl.handle.net/2142/72834.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
McKenzie, George. “Modern Rossi alpha measurements.” 2015. Web. 16 Feb 2019.
Vancouver:
McKenzie G. Modern Rossi alpha measurements. [Internet] [Thesis]. University of Illinois – Urbana-Champaign; 2015. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/2142/72834.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
McKenzie G. Modern Rossi alpha measurements. [Thesis]. University of Illinois – Urbana-Champaign; 2015. Available from: http://hdl.handle.net/2142/72834
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

North Carolina State University
21.
Hiruta, Hikaru.
Advanced Computational Methodology for Full-Core Neutronics Calculations.
Degree: PhD, Nuclear Engineering, 2004, North Carolina State University
URL: http://www.lib.ncsu.edu/resolver/1840.16/5463
► The modern computational methodology for reactor physics calculations is based on single–assembly transport calculations with reflective boundary conditions that generate homogenized few–group data, and core–level…
(more)
▼ The modern computational methodology for
reactor physics calculations is based on single–assembly transport calculations with reflective boundary conditions that generate homogenized few–group data, and core–level coarse-mesh diffusion calculations that evaluate a large-scale behavior of the scalar flux. Recently, an alternative approach has been developed. It is based on the low-order equations of the quasidiffusion (QD) method in order to account accurately for complicated transport effects in full–core calculations. The LOQD equations can capture transport effects to an arbitrary degree of accuracy. This approach is combined with single–assembly transport calculations that use special albedo boundary conditions which enable one to simulate efficiently effects of an unlike neighboring assembly on assembly's group data.
In this dissertation, we develop homogenization methodology based on the LOQD equations and spatially consistent coarse–mesh finite element discretization methods for the 2D low–order quasidiffusion equations for the full–core calculations. The coarse–mesh solution generated by this method preserves a number of spatial polynomial moments of the fine–mesh transport solution over coarse cells. The proposed method reproduces accurately the complicated large–scale behavior of the transport solution within assemblies. To demonstrate accuracy of the developed method, we present numerical results of calculations of test problems that simulate interaction of MOX and uranium assemblies.
We also develop a splitting method that can efficiently solve coarse-mesh discretized low-order quasidiffusion (LOQD) equations. The presented method splits the LOQD problem into two parts: (i) the D-problem that captures a significant part of transport solution in the central parts of assemblies and can be reduced to a diffusion-type equation, and (ii) the Q-problem that accounts for the complicated behavior of the transport solution near assembly boundaries. Independent coarse-mesh discretizations are applied: the D-problem equations are approximated by means of a finite-element method, whereas the Q-problem equations are discretized using a finite-volume method. Numerical results demonstrate the efficiency of the presented methodology. This methodology can be used to modify existing diffusion codes for full-core calculations (which already solve a version of the D-problem) to account for transport effects.
Advisors/Committee Members: Dmitriy Y. Anistratov, Committee Chair (advisor), Paul J. Turinsky, Committee Member (advisor), Robin P. Gardner, Committee Member (advisor), Zhilin Li, Committee Member (advisor).
Subjects/Keywords: Reactor Physics; Neutron Transport
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hiruta, H. (2004). Advanced Computational Methodology for Full-Core Neutronics Calculations. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/5463
Chicago Manual of Style (16th Edition):
Hiruta, Hikaru. “Advanced Computational Methodology for Full-Core Neutronics Calculations.” 2004. Doctoral Dissertation, North Carolina State University. Accessed February 16, 2019.
http://www.lib.ncsu.edu/resolver/1840.16/5463.
MLA Handbook (7th Edition):
Hiruta, Hikaru. “Advanced Computational Methodology for Full-Core Neutronics Calculations.” 2004. Web. 16 Feb 2019.
Vancouver:
Hiruta H. Advanced Computational Methodology for Full-Core Neutronics Calculations. [Internet] [Doctoral dissertation]. North Carolina State University; 2004. [cited 2019 Feb 16].
Available from: http://www.lib.ncsu.edu/resolver/1840.16/5463.
Council of Science Editors:
Hiruta H. Advanced Computational Methodology for Full-Core Neutronics Calculations. [Doctoral Dissertation]. North Carolina State University; 2004. Available from: http://www.lib.ncsu.edu/resolver/1840.16/5463
22.
Talley, Kemper Dyar.
Beta-Delayed Neutron Data and Models for SCALE.
Degree: 2016, University of Tennessee – Knoxville
URL: https://trace.tennessee.edu/utk_graddiss/4170
► Recent advancements in experimental and theoretical nuclear physics have yielded new data and models that more accurately describe the decay of fission products compared to…
(more)
▼ Recent advancements in experimental and theoretical nuclear physics have yielded new data and models that more accurately describe the decay of fission products compared to historical data currently used for many applications. This work examines the effect of the adopting the Effective Density Model theory for beta-delayed neutron emission probability on calculations of delayed-neutron production and fission product nuclide concentrations after fission bursts as well as the total delayed neutron fraction in comparison with the Keepin 6-group model. We use ORIGEN within the SCALE code package for these calculations. We show quantitative changes to the isotopic concentrations for fallout nuclides and delayed neutron production after fission bursts on the order of a few percent. We also show that the changes are larger at small times for short lived fission products, and that corrections to the cumulative fission product yields has an impact upon the total delayed neutron fraction for 235U [Uranium 235]. The effect of modeling the β2n [beta delayed double neutron emission] decay mode is also studied but no significant changes from the single beta-delayed neutron emission is currently seen.
Subjects/Keywords: Neutron Emission; Beta Decay; Nuclear Physics; Reactor Physics; Nuclear Data; SCALE; Nuclear; Nuclear Engineering
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APA ·
Chicago ·
MLA ·
Vancouver ·
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APA (6th Edition):
Talley, K. D. (2016). Beta-Delayed Neutron Data and Models for SCALE. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/4170
Chicago Manual of Style (16th Edition):
Talley, Kemper Dyar. “Beta-Delayed Neutron Data and Models for SCALE.” 2016. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed February 16, 2019.
https://trace.tennessee.edu/utk_graddiss/4170.
MLA Handbook (7th Edition):
Talley, Kemper Dyar. “Beta-Delayed Neutron Data and Models for SCALE.” 2016. Web. 16 Feb 2019.
Vancouver:
Talley KD. Beta-Delayed Neutron Data and Models for SCALE. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2016. [cited 2019 Feb 16].
Available from: https://trace.tennessee.edu/utk_graddiss/4170.
Council of Science Editors:
Talley KD. Beta-Delayed Neutron Data and Models for SCALE. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2016. Available from: https://trace.tennessee.edu/utk_graddiss/4170
23.
Serra, André da Silva.
Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem.
Degree: PhD, Física, 2012, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-121339/
;
► O presente trabalho visa contribuir com o desenvolvimento sistemático de novas metodologias experimentais da medida da reatividade de arranjos físseis subcríticos, utilizando: estatísticas de alta…
(more)
▼ O presente trabalho visa contribuir com o desenvolvimento sistemático de novas metodologias experimentais da medida da reatividade de arranjos físseis subcríticos, utilizando: estatísticas de alta ordem das contagens de nêutrons com detectores no modo pulso, o recente conceito de reatividade generalizada, e as instalações do reator IPEN/MB-01. Este trabalho reuniu em um só texto diversos aspectos da implementação destes tipos de medidas. Diferentemente das demais técnicas utilizadas nas medidas da reatividade subcrítica, as metodologias apresentadas neste trabalho tem o potencial para permitir a medida experimental da reatividade subcrítica sem a necessidade da estimativa prévia de quaisquer outros parâmetros cinéticos, obtidos de forma teórica ou experimental, calibração de fontes externas ou detectores.A princípio, os métodos estatísticos de alta ordem das contagens de nêutrons permitem obter diretamente o valor da subcriticalidade (ou o fator de multiplicação) de um arranjo físsil, independentemente do modelo de física subcrítica utilizado, sem a utilização de infra-estrutura diferenciada (como uma fonte pulsada de nêutrons), sendo uma extensão natural das metodologias que utilizam estatísticas de ordens inferiores - por exemplo, Feymann-. E este conteúdo estatístico diferenciado dos momentos de altas ordens das contagens de nêutrons, o principal motivador da implementação deste trabalho. Apesar de suas potencialidades, a implementação experimental do método esbarra no tempo e taxa de aquisição de dados; ou seja, na quantidade de conteúdo estatístico necessária para a obtenção de medida útil. Exatamente esta dificuldade impediu a obtenção de uma medida útil/prática nas instalações do reator IPEN/MB-01. Existem, entretanto, outras formas de explorar estatísticas ordem superior. Por exemplo, uma extensão do método de Rossi- sugerida neste trabalho pode utilizar auto bi-correlações (coincidências triplas não acidentais de contagens). A despeito do alto valor das incertezas, os aspectos estatísticos fundamentais de uma medida foram preservados nos métodos empregados neste trabalho. O método das auto bicorrelações é conceitualmente mais robusto contra as influências do tempo morto do sistema de aquisição de dados. Ao longo de sua execução, o presente trabalho visou preencher algumas lacunas de procedimentos experimentais aparentemente pouco abordadas por outros autores, permitindo estabelecer métodos estatisticamente mais rigorosos. Entre as contribuições neste sentido destacam-se, entre outras, as correções por tempo morto ou as geradas pela correlação entre os parâmetros estatísticos em tela. Do ponto de vista teórico, este trabalho sugere duas maneiras originais de abordar o mesmo problema da utilização de estatísticas de altas ordens: (a) auto bicorrelações; e (2) os biespectros de densidade de espectral de potência própria, sendo o primeiro explorado experimentalmente/estatisticamente em detalhes.
The present work aims to contribute to the systematic development of new experimental methods of measuring the…
Advisors/Committee Members: Pascholati, Paulo Reginaldo, Santos, Adimir dos.
Subjects/Keywords: cinética de reatores; estatísticas; física de reatores; nuclear reactors; reactivity; reactor kinetics; reactor physics; reatividade; reatores nucleares; statistics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Serra, A. d. S. (2012). Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-121339/ ;
Chicago Manual of Style (16th Edition):
Serra, André da Silva. “Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem.” 2012. Doctoral Dissertation, University of São Paulo. Accessed February 16, 2019.
http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-121339/ ;.
MLA Handbook (7th Edition):
Serra, André da Silva. “Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem.” 2012. Web. 16 Feb 2019.
Vancouver:
Serra AdS. Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem. [Internet] [Doctoral dissertation]. University of São Paulo; 2012. [cited 2019 Feb 16].
Available from: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-121339/ ;.
Council of Science Editors:
Serra AdS. Determinação experimental da reatividade subcrítica utilizando correlação de terceira ordem. [Doctoral Dissertation]. University of São Paulo; 2012. Available from: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-26032013-121339/ ;

Texas A&M University
24.
Sternat, Matthew Ryan 1982-.
Development of Technical Nuclear Forensics for Spent Research Reactor Fuel.
Degree: 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/148202
► Pre-detonation technical nuclear forensics techniques for research reactor spent fuel were developed in a collaborative project with Savannah River National Lab ratory. An inverse analysis…
(more)
▼ Pre-detonation technical nuclear forensics techniques for research
reactor spent fuel were developed in a collaborative project with Savannah River National Lab ratory. An inverse analysis method was employed to reconstruct
reactor parameters from a spent fuel sample using results from a radiochemical analysis. In the inverse analysis, a
reactor physics code is used as a forward model. Verification and validation of different
reactor physics codes was performed for usage in the inverse analysis.
The verification and validation process consisted of two parts. The first is a variance analysis of Monte Carlo
reactor physics burnup simulation results. The codes used in this work are MONTEBURNS and MCNPX/CINDER. Both utilize Monte Carlo transport calculations for reaction rate and flux results. Neither code has a variance analysis that will propagate through depletion steps, so a method to quantify and understand the variance propagation through these depletion calculations was developed.
The second verification and validation process consisted of comparing
reactor physics code output isotopic compositions to radiochemical analysis results. A sample from an Oak Ridge Research
Reactor spent fuel assembly was acquired through a drilling process. This sample was then dissolved in nitric acid and diluted in three different quantities, creating three separate samples. A radiochemical analysis was completed and the results were compared to simulation outputs at different levels ofdetail.
After establishing a forward model, an inverse analysis was developed to re-construct the burnup, initial uranium isotopic compositions, and cooling time of a research
reactor spent fuel sample. A convergence acceleration technique was used that consisted of an analytical calculation to predict burnup, initial 235U, and 236U enrichments. The analytic calculation results may also be used stand alone or in a database search algorithm. In this work, a
reactor physics code is used as a for- ward model with the analytic results as initial conditions in a numerical optimization algorithm. In the numerical analysis, the burnup and initial uranium isotopic com- positions are reconstructed until the iterative spent fuel characteristics converge with the measured data.
Upon convergence of the sample?s burnup and initial uranium isotopic composition, the cooling time can be reconstructed. To reconstruct cooling time, the standard decay equation is inverted and solved for time. Two methods were developed. One method uses the converged burnup and initial uranium isotopic compositions along in a
reactor depletion simulation. The second method uses an isotopic signature that does not decay out of its mass bin and has a simple production chain. An example would be 137Cs which decays into the stable 137Ba. Similar results are achieved with both methods, but extended shutdown time or time away from power results in over prediction of the cooling time.
The over prediction of cooling time and comparison of different burnup reconstruction isotope…
Advisors/Committee Members: Charlton, William S (advisor), Boyle, David R (committee member), Adams, Marvin L (committee member), Folden, Charles M (committee member).
Subjects/Keywords: Attribution; Spent Fuel; Research Reactor; Savannah River National Laboratory; Radiochemical Analysis; Inverse Reactor Physics; Inverse Problems; Nuclear Forensics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Sternat, M. R. 1. (2012). Development of Technical Nuclear Forensics for Spent Research Reactor Fuel. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148202
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sternat, Matthew Ryan 1982-. “Development of Technical Nuclear Forensics for Spent Research Reactor Fuel.” 2012. Thesis, Texas A&M University. Accessed February 16, 2019.
http://hdl.handle.net/1969.1/148202.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sternat, Matthew Ryan 1982-. “Development of Technical Nuclear Forensics for Spent Research Reactor Fuel.” 2012. Web. 16 Feb 2019.
Vancouver:
Sternat MR1. Development of Technical Nuclear Forensics for Spent Research Reactor Fuel. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/1969.1/148202.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sternat MR1. Development of Technical Nuclear Forensics for Spent Research Reactor Fuel. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148202
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

KTH
25.
Kotchoubey, Jurij.
POLCA-T Neutron Kinetics Model Benchmarking.
Degree: Reactor Technology, 2015, KTH
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176096
► The demand for computational tools that are capable to reliably predict the behavior of a nuclear reactor core in a variety of static and…
(more)
▼ The demand for computational tools that are capable to reliably predict the behavior of a nuclear reactor core in a variety of static and dynamic conditions does inevitably require a proper qualification of these tools for the intended purposes. One of the qualification methods is the verification of the code in question. Hereby, the correct implementation of the applied model as well as its flawless implementation in the code are scrutinized. The present work concerns with benchmarking as a substantial part of the verification of the three-dimensional, multigroup neutron kinetics model employed in the transient code POLCA-T. The benchmarking is done by solving some specified and widely used space-time kinetics benchmark problems and comparing the results to those of other, established and well-proven spatial kinetics codes. It is shown that the obtained results are accurate and consistent with corresponding solutions of other codes. In addition, a sensitivity analysis is carried out with the objective to study the sensitivity of the POLCA-T neutronics to variations in different numerical options. It is demonstrated that the model is numerically stable and provide reproducible results for a wide range of various numerical settings. Thus, the model is shown to be rather insensitive to significant variations in input, for example. The other consequence of this analysis is that, depending on the treated transient, the computing costs can be reduced by, for instance, employing larger time-steps during the time-integration process or using a reduced number of iterations. Based on the outcome of this study, one can finally conclude that the POLCA-T neutron kinetics is modeled and implemented correctly and thus, the model is fully capable to perform the assigned tasks.
Subjects/Keywords: POLCA-T; Neutronics; Neutron Kinetics; Benchmarking; Reactor Kinetics; Space-Time Kinetics; Reactor Physics; POLCA-T; Kinetik; Neutronkinetik; Benchmarking; Reaktorfysik
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kotchoubey, J. (2015). POLCA-T Neutron Kinetics Model Benchmarking. (Thesis). KTH. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176096
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kotchoubey, Jurij. “POLCA-T Neutron Kinetics Model Benchmarking.” 2015. Thesis, KTH. Accessed February 16, 2019.
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176096.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kotchoubey, Jurij. “POLCA-T Neutron Kinetics Model Benchmarking.” 2015. Web. 16 Feb 2019.
Vancouver:
Kotchoubey J. POLCA-T Neutron Kinetics Model Benchmarking. [Internet] [Thesis]. KTH; 2015. [cited 2019 Feb 16].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176096.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kotchoubey J. POLCA-T Neutron Kinetics Model Benchmarking. [Thesis]. KTH; 2015. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176096
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Missouri University of Science and Technology
26.
Compton, William Kirby.
Impact of configuration variations on small modular reactor core performance.
Degree: M.S. in Nuclear Engineering, Nuclear Engineering, Missouri University of Science and Technology
URL: http://scholarsmine.mst.edu/masters_theses/7391
► "One of the most promising new reactor designs is the Small Modular Reactor (SMR). These reactors, which operate under 300 MWe, will help bring…
(more)
▼ "One of the most promising new reactor designs is the Small Modular Reactor (SMR). These reactors, which operate under 300 MWe, will help bring cheap and safe nuclear energy to remote and centralized locations alike. Their ease of construction, advanced passive safety features, and cost effectiveness make these reactors an intriguing option for the near future.
In the work presented here, a neutronics analysis of the Westinghouse SMR was performed. Westinghouse's SMR design is a scaled down version of their AP1000 plant and will produce about 225 MWe of power. Though the parameters of the reactor core will be modeled after the AP1000, the exact layout of the core has not been released. For this research project, six initial core configurations have been proposed. The Monte Carlo method was used to calculate several reactor parameters by means of the MCNP6 code. Beginning of life calculations such as effective multiplication factor, delayed neutron fraction, temperature coefficients of reactivity, and neutron flux profile have been performed. Three refueling cycles have then been completed to observe how the six cores perform within the cycle up to the point when an equilibrium fuel cycle has been reached, while extracting data pertaining to multiplication factor, burnup, composition of spent fuel, and flux profile. These calculations will help to determine the feasibility and the effectiveness of the six potential core configurations." – Abstract, page iii.
Subjects/Keywords: MCNP; Reactor Physics; Small Modular Reactor; Nuclear Engineering
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Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Compton, W. K. (n.d.). Impact of configuration variations on small modular reactor core performance. (Masters Thesis). Missouri University of Science and Technology. Retrieved from http://scholarsmine.mst.edu/masters_theses/7391
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Chicago Manual of Style (16th Edition):
Compton, William Kirby. “Impact of configuration variations on small modular reactor core performance.” Masters Thesis, Missouri University of Science and Technology. Accessed February 16, 2019.
http://scholarsmine.mst.edu/masters_theses/7391.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
MLA Handbook (7th Edition):
Compton, William Kirby. “Impact of configuration variations on small modular reactor core performance.” Web. 16 Feb 2019.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Vancouver:
Compton WK. Impact of configuration variations on small modular reactor core performance. [Internet] [Masters thesis]. Missouri University of Science and Technology; [cited 2019 Feb 16].
Available from: http://scholarsmine.mst.edu/masters_theses/7391.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Council of Science Editors:
Compton WK. Impact of configuration variations on small modular reactor core performance. [Masters Thesis]. Missouri University of Science and Technology; Available from: http://scholarsmine.mst.edu/masters_theses/7391
Note: this citation may be lacking information needed for this citation format:
No year of publication.

McMaster University
27.
Tan, Andrew.
Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code.
Degree: MASc, 2015, McMaster University
URL: http://hdl.handle.net/11375/18666
► The goal of this thesis is to study the transient behaviour of the SLOWPOKE-2 reactor using Monte-Carlo simulations with the G4-STORK code. G4-STORK is a…
(more)
▼ The goal of this thesis is to study the transient behaviour of the SLOWPOKE-2 reactor using Monte-Carlo simulations with the G4-STORK code. G4-STORK is a 3-dimensional Monte-Carlo code derived from the GEANT4 physics simulation toolkit. Methods were developed for the proper treatment of delayed neutrons and a lumped capacitance model was used to track the time-dependent fuel properties (temperature, density) based on the fission power. By validating the methods in G4-STORK with experimental measurements we hope to extend our understanding of reactor transients as well as further develop our methods to model the transients of the next generation reactor designs. A SLOWPOKE-2 reactor such as the one at RMC was chosen for simulation due to its compact size, and well-known transient response of control rod removal and measured temperature feedback. Static simulations in G4-STORK find a neutron flux of order 1012 cm−2 s−1 which agrees with experiment and a control rod worth of (4.9 ± 2.0) mk compared to the experimentally measured worth of 5.45 mk. Transient simulations from rod pluck-out find similar trends to the experimental findings as our results suggest a negative temperature feedback due to the doppler broadening of the U-238 absorption spectrum which contributes to the overall safety mechanism seen in the SLOWPOKE reactor. It is determined that the methods in G4-STORK provide a reasonable ability to simulate reactor transients and it is recommended that a full-core thermal-hydraulics model be coupled to G4-STORK to achieve a higher level of accuracy.
Thesis
Master of Applied Science (MASc)
Advisors/Committee Members: Buijs, Adriaan, Engineering Physics and Nuclear Engineering.
Subjects/Keywords: Nuclear Physics; Reactor Physics; Nuclear Engineering; Simulations; Transient; Transient Simulations; GEANT4; G4-STORK; Computational Physics; SLOWPOKE-2
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Tan, A. (2015). Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/18666
Chicago Manual of Style (16th Edition):
Tan, Andrew. “Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code.” 2015. Masters Thesis, McMaster University. Accessed February 16, 2019.
http://hdl.handle.net/11375/18666.
MLA Handbook (7th Edition):
Tan, Andrew. “Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code.” 2015. Web. 16 Feb 2019.
Vancouver:
Tan A. Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code. [Internet] [Masters thesis]. McMaster University; 2015. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/11375/18666.
Council of Science Editors:
Tan A. Transient Simulations of the SLOWPOKE-2 Reactor Using the G4-STORK Code. [Masters Thesis]. McMaster University; 2015. Available from: http://hdl.handle.net/11375/18666

McMaster University
28.
Russell, Liam F.
Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit.
Degree: MASc, 2012, McMaster University
URL: http://hdl.handle.net/11375/12657
► When the material or geometry of a reactor varies with time, the neutron flux will respond in the form of a reactor transient. These…
(more)
▼ When the material or geometry of a reactor varies with time, the neutron flux will respond in the form of a reactor transient. These transients can occur during normal operations when control rods are moved or the reactor is refuelled (CANDU). During a reactor accident, the transient response is especially important because the reactor properties vary quickly with large amplitudes. Therefore, better understanding these conditions allows for improved identification, prevention and mitigation of reactor transients. However, current nuclear simulation codes are generally limited in their ability to model transient behaviour. The NStable code was created to model time-dependent neutron populations in multiplying mediums using the Geant4 Monte Carlo toolkit. The neutron population is allowed to evolve in time, but is periodically renormalized so that the total number of neutrons is constrained within a manageable range. This ensures that the simulation is viable even in highly sub- or supercritical environments. Since Geant4 was not intrinsically designed to track a neutron population over "long" time periods (up to 10 s), the population renormalization mechanisms needed to be created and integrated with Geant4. Additionally, nuclear reactor analysis functionality was added to calculate important quantities such as keff. The NStable code was validated using three established nuclear simulation codes: MCNP 5, DRAGON 3.06J, and TART 2005. The validation cases compared spatial distributions and criticality estimates for either homogeneous spheres (uranium-235 or a uranium-heavy water mixture) or the standard CANDU 6 lattice cell. For all three systems, the criticality estimates in NStable agreed with the appropriate validation code within 10 mk (TART for the spheres and DRAGON for the CANDU 6 lattice). Finally, the NStable code was also used to simulate a temperature transient in a UHW sphere where the temperature linear increased by 700 K over 50 ms. In response to the increasing temperature, keff decreased by 100 mk over the same period. In the future, transient modelling in NStable should be investigated further to reproduce actual experimental results, and to couple NStable with a thermohydraulics code to simulate a full transient response.
Master of Applied Science (MASc)
Advisors/Committee Members: Buijs, Adriaan, Jonkmans, Guy, Engineering Physics and Nuclear Engineering.
Subjects/Keywords: Monte Carlo; reactor physics; nuclear engineering; stochastic; time-dependent; Geant4; Engineering Physics; Nuclear; Nuclear Engineering; Engineering Physics
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Russell, L. F. (2012). Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/12657
Chicago Manual of Style (16th Edition):
Russell, Liam F. “Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit.” 2012. Masters Thesis, McMaster University. Accessed February 16, 2019.
http://hdl.handle.net/11375/12657.
MLA Handbook (7th Edition):
Russell, Liam F. “Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit.” 2012. Web. 16 Feb 2019.
Vancouver:
Russell LF. Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit. [Internet] [Masters thesis]. McMaster University; 2012. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/11375/12657.
Council of Science Editors:
Russell LF. Simulation of Time-Dependent Neutron Populations for Reactor Physics Applications Using the Geant4 Monte Carlo Toolkit. [Masters Thesis]. McMaster University; 2012. Available from: http://hdl.handle.net/11375/12657

University of Ontario Institute of Technology
29.
Colton, Ashlea V. K.
Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients.
Degree: 2016, University of Ontario Institute of Technology
URL: http://hdl.handle.net/10155/755
► To model the neutronic physics behavior of the core in CANDU pressure tube type heavy water reactors with natural-uranium fuel, two levels of calculations are…
(more)
▼ To model the neutronic
physics behavior of the core in CANDU pressure tube type heavy water reactors with natural-uranium fuel, two levels of calculations are required. Initially, lattice-level transport calculations are carried out to obtain, with high detail and accuracy, the flux distribution inside the lattice cell and composition of the nuclear fuel. Lattice calculations use many (30- 180) energy groups and detailed geometric information to model the fuel channel and the fuel contained within.
Once the lattice calculations are complete, the fuel compositions obtained can be used to generate cell-homogenized macroscopic cross-sections condensed to two energy groups, for use in full-core diffusion calculations. Two-group cell-homogenized cross-sections work to acceptable levels of accuracy in most full-core configurations. However, challenges appear when modelling the neutron flux at the fuel-reflector interface (at the boundary of the
reactor).
This work aims to improve the neutron flux estimates obtained in three-dimensional diffusion calculations by using diffusion coefficients fitted to transport results. It will be shown that significant improvements (>10%) can be made for modeling the neutron
physics at the core-reflector interface.
Advisors/Committee Members: Nichita, Eleodore.
Subjects/Keywords: Reactor physics; Diffusion theory; Heavy water reactors; Natural uranium; Core reflector interface
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APA (6th Edition):
Colton, A. V. K. (2016). Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients. (Thesis). University of Ontario Institute of Technology. Retrieved from http://hdl.handle.net/10155/755
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Colton, Ashlea V K. “Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients.” 2016. Thesis, University of Ontario Institute of Technology. Accessed February 16, 2019.
http://hdl.handle.net/10155/755.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Colton, Ashlea V K. “Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients.” 2016. Web. 16 Feb 2019.
Vancouver:
Colton AVK. Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients. [Internet] [Thesis]. University of Ontario Institute of Technology; 2016. [cited 2019 Feb 16].
Available from: http://hdl.handle.net/10155/755.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Colton AVK. Improved 3D modelling of CANDU reactors using transport-fitted diffusion coefficients. [Thesis]. University of Ontario Institute of Technology; 2016. Available from: http://hdl.handle.net/10155/755
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
30.
Rossi, Lubianka Ferrari Russo.
Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear.
Degree: PhD, Tecnologia Nuclear - Reatores, 2014, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12022015-154545/
;
► Este trabalho apresenta um novo método para o cálculo dos coecientes de sensibilidade, através da união do metodo diferencial e da teoria da perturbação generalizada,…
(more)
▼ Este trabalho apresenta um novo método para o cálculo dos coecientes de sensibilidade, através da união do metodo diferencial e da teoria da perturbação generalizada, que são os dois métodos tradicionalmente utilizados em física de reatores para a obtenção de tais grandezas. Esses dois métodos apresentam algumas deciências tornando os cálculos dos coeficientes de sensibilidade lentos ou computacionalmente exaustivos, mas unindo-os e possível eliminar as deciências apresentadas por ambos e obter uma nova equação para o coe- ciente de sensibilidade. O método proposto neste trabalho foi aplicado em um reator do tipo PWR , onde foi feita análise de sensibilidade da produção e da razão de conversão do 239Pu, para um ciclo de 120 dias de queima. O código utilizado para a análise de queima e análise de sensibilidade, o CINEW, foi desenvolvido durante este trabalho e os resultados obtidos foram comparados com os códigos amplamente utilizados em física de reatores, como o CINDER e o SERPENT. As conclusões obtidas foram que o novo método matemático para a obtenção dos coeficientes de sensibilidade e o CINEW, além de fornecer agilidade numérica também presentam eciência e segurança. Pois o novo método matemático para a obtenção dos coeficientes quando comparados com os métodos tradicionais utilizados para a análise de sensibilidade, mostram resultados satisfatórios, mesmo quando o método utiliza aproximações matemáticas que diferem do método proposto, e com a vantagem de não apresentar as deciências apresentadas pelos métodos diferencial e da teoria da perturbação generalizada. As análises de queima obtidas pelo CINEW foram comparadas com o CINDER, que mostraram uma diferença aceitável, apesar do CINDER apresentar alguns problemas computacionais que advém da época em que foi feito. A originalidade deste trabalho e a aplicação do método proposto em problemas que envolvem dependência temporal e a elaboração do primerio código nacional que faz análise de queima e análise de sensibilidade.
The main target of this study is to introduce a new method for calculating the coefficients of sensibility through the union of differential method and generalized perturbation theory, which are the two methods generally used in reactor physics to obtain such variables. These two methods, separated, have some issues turning the sensibility coefficients calculation slower or computationally exhaustive. However, putting them together, it\'s possible to repair these issues and build a new equation for the coecient of sensibility. The method introduced in this study was applied in a PWR reactor, where it was performed the sensibility analysis for the production and 239Pu conversion rate during 120 days (1 cycle) of burnup. The computational code used for both burnup and sensibility analysis, the CINEW, was developed in this study and all the results were compared with codes widely used in reactor physics, such as CINDER and SERPENT. The new mathematical method for calculating the sensibility coefficients and the code CINEW provide good numerical…
Advisors/Committee Members: Santos, Adimir dos.
Subjects/Keywords: analise de sensibilidade; coeficientes de sensibilidade; física de reatores; reactor physics; sensibility analysis; sensitivity coecients
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APA (6th Edition):
Rossi, L. F. R. (2014). Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12022015-154545/ ;
Chicago Manual of Style (16th Edition):
Rossi, Lubianka Ferrari Russo. “Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear.” 2014. Doctoral Dissertation, University of São Paulo. Accessed February 16, 2019.
http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12022015-154545/ ;.
MLA Handbook (7th Edition):
Rossi, Lubianka Ferrari Russo. “Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear.” 2014. Web. 16 Feb 2019.
Vancouver:
Rossi LFR. Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear. [Internet] [Doctoral dissertation]. University of São Paulo; 2014. [cited 2019 Feb 16].
Available from: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12022015-154545/ ;.
Council of Science Editors:
Rossi LFR. Acoplamento entre os métodos diferencial e da teoria da perturbação para o cálculo dos coeficientes de sensibilidade em problemas de transmutação nuclear. [Doctoral Dissertation]. University of São Paulo; 2014. Available from: http://www.teses.usp.br/teses/disponiveis/85/85133/tde-12022015-154545/ ;
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