Effect of reactor irradiation on the dissociation pressure of zirconium hydride

Abstract

An earlier study of the temperature dependence of the dissociation pressure of zirconium hydride and its dependence on hydrogen content showed that during irradiation with a neutron flux of intensity ~ 1014 neutrons/cm z .sec (E _> 0.1 MeV) the equilibrium pressure was greater than under the same conditions without irradiation [1 ]. These and other data presented in the present paper were obtained when studying samples of zirconium hydride irradiated in hermetic ampoules furnished with a system of pressure measurement and a controllable rate of hydrogen extraction, enabling the hydrogen content of the samples to be varied.

Hydrogen isotope population near dislocations in zirconium from molecular dynamics

“…This suggests that irradiated dislocations do not necessarily increase the overall solubility of materials. Although the phenomenon has not been reported previously, it aligns with the experimental observation that hydrogen equilibrium pressure increases during irradiation [ 35 ], which is difficult to understand if all defects attract hydrogen. Note that our results are obtained from a specific dislocation dipole configuration.…”

“…The discoveries that non-glide dislocations have higher isotope peaks at core and dislocations not necessarily increase the total isotope content in samples are important because they provide a mechanism to explain the counterintuitive experimental observation that hydrogen equilibrium pressure increases during irradiation [ 35 ]. These understandings can help improve applications were hydrogen isotope population and diffusion are used as design criteria.…”

Recommendations for Tritium Science and Technology Research and Development in Support of the Tritium Readiness Campaign, TTP-7-084

“…Revision 0 Page 21 of 54 equilibrium pressure of hydrogen over Zr can be enhanced by radiation (Karasev et al 1974). If true for TPBAR getters at prototypic operating conditions, this could explain much of the remaining discrepancy between predicted and observed tritium release from the TPBAR.…”