University of Notre Dame
Kyle Stewart Haygarth.
Radiolysis Studies in Supercritical Water</h1>.
Degree: MS, Chemistry and Biochemistry, 2009, University of Notre Dame
This dissertation will consist of three
topics which fall under the general umbrella of studies of water
radiolysis at supercritical temperatures and pressures for nuclear
power applications. Introductory material common to all chapters in
this dissertation relating to water radiolysis in supercritical
water conditions is presented in the opening chapter. Chapter 2
explores “The Application of Hydrogen Water Chemistry to Suppress
Net Radiolysis in Supercritical Water.” One of the largest problems
in all nuclear reactors (including the proposed Supercritical Water
Reactor (SCWR) design) is stress corrosion cracking (SCC) of steel
pipes. This is controlled by the corrosion potential, on which the
O2 and H2O2 species formed in water radiolysis have a major
impact.1,2 Even at low concentrations they strongly influence
corrosion kinetics. In order to control the corrosion potential, a
successful strategy employing hydrogen water chemistry inhibits
radiolytic decomposition of the coolant by the minimum addition of
hydrogen (the critical hydrogen concentration) to the primary
cooling water.3 Experiments showing that this strategy can be
successfully applied in supercritical water reactors are discussed.
We have confirmed that suppression of O2 in the bulk water is
possible in the sub-and supercritical temperature regimes. However,
results indicate that substantial hydrogen (no O2) is still
generated by radiation-induced reactions on the walls of the metal
flow system, an effect absent at lower (sub 350ÌÄåâÌâå¡C)
temperatures. In fact, excess hydrogen seems to be generated at
supercritical temperatures. Chapter 3 explores “Solvated Electron
(e-aq) Yields in Supercritical Water.” In support of an ongoing
yield measurement program collaboration with the University of
Wisconsin, Madison, radiolysis yields of H, H2, and e-aq were
measured as a function of temperature and as a function of pressure
(or density) in the mixed neutron/gamma radiation field from a
nuclear reactor at the University of Wisconsin. Reactor data is
compared with nearly identical experiments run with a 3MeV van de
Graaff accelerator to measure the same yields in the absence of
neutron radiolysis. Radiolysis was carried out using a beam of 2-3
MeV electrons from a van de Graaff accelerator and SF6 was used as
a specific scavenger for the hydrated electron. Reduction of SF6 on
the walls of the irradiation zone was apparent and subsequently
investigated. Chapter 4 explores “Carbonate Radical Formation in
Radiolysis of Sodium Carbonate and Bicarbonate Solutions up to
250ÌÄåâÌâå¡C and the Mechanism of its Second Order Decay.” Pulse
radiolysis experiments published several years ago raised the
possibility that the carbonate radical formed from reaction of
ÌÄå¢Ì¢åâåÂÌâå¢OH radicals with either HCO3- or CO32- might actually
exist predominantly as a dimer form, e.g. ÌÄå¢Ì¢åâåÂÌâå¢(CO3)23-.
In this work we re-examine the data upon which this suggestion was
based, and find that the original data analysis is flawed. Upon
re-analysis of the published data for sodium…
Advisors/Committee Members: Ian Carmichael, Committee Member, David M. Bartels, Committee Member.
Subjects/Keywords: hydrogen water chemistry; stress corrosion cracking; corrosion
to Zotero / EndNote / Reference
APA (6th Edition):
Haygarth, K. S. (2009). Radiolysis Studies in Supercritical Water</h1>. (Masters Thesis). University of Notre Dame. Retrieved from https://curate.nd.edu/show/df65v69500q
Chicago Manual of Style (16th Edition):
Haygarth, Kyle Stewart. “Radiolysis Studies in Supercritical Water</h1>.” 2009. Masters Thesis, University of Notre Dame. Accessed June 25, 2019.
MLA Handbook (7th Edition):
Haygarth, Kyle Stewart. “Radiolysis Studies in Supercritical Water</h1>.” 2009. Web. 25 Jun 2019.
Haygarth KS. Radiolysis Studies in Supercritical Water</h1>. [Internet] [Masters thesis]. University of Notre Dame; 2009. [cited 2019 Jun 25].
Available from: https://curate.nd.edu/show/df65v69500q.
Council of Science Editors:
Haygarth KS. Radiolysis Studies in Supercritical Water</h1>. [Masters Thesis]. University of Notre Dame; 2009. Available from: https://curate.nd.edu/show/df65v69500q