RESEARCH AND DEVELOPMENT OF METAL HYDRIDES. Summary Report for October 1, 1958-September 30, 1960

Abstract

DISCLAIMER LAK-10NOTICES When Government drawings, specifications o r other data a r e e d f o r any purpose other than in connection with a definitely r e l a t e d government p r o c u r e m e n t operation, the United States Government thereby i n c u r s no responsibility nor any obligation whatsoever; and the f a c t that the government m a y have formulated, furnished, o r i n any way supplied the s a i d drawings , specifications, o r data, i s not to be r e g a r d e d by implication o r otherwise as i n any m a n n e r licensing the holder o r any other p e r s o n o r corporation, o r conveying any right o r p e r m i s s i o n to manufacture, u s e , o r s e l l any patented invention that m a y i n a n y way be r e l a t e d thereto.This document m a y not be reproduced o r published in any f o r m in whole o r i n p a r t without p r i o r approval of the government. this i s a p r o g r e s s r e p o r t , the information h e r e i n is tentative and subject to changes, c o r r e c t i o n s , modifications. A detailed study of the fundamental relations i n the zirconiumhydrogen s y s t e m was m a d e in o r d e r to c l a r i f y the m a n y points of dispute and to evolve a complete picture describing all p h a s e s of this s y stem. These data provided the n e c e s s a r y foundation f r o m which an intelligent evaluation of the engineering p r o p e r t i e s of p u r e and alloyed zirconium could be made.Another phase of this work was directed toward a n engineering evaluation of means f o r utilizing the various high c r o s s -s e c t i o n m e t a l hydrides in shielding o r control applications. These m a t e r i a l s would combine the p r o c e s s e s of thermalization and absorption, they a r e of considerable i n t e r e s t €or u s e i n shi.elding o r controlling e p i t h e r m a l r e a c t o r s L)Consequently,

Ab initio thermo-elasticity of δ-MHx (M=Zr, Ti)

“…To dissolve the other hydrides, high temperature measurements were required. Such measurements produced experimental values of ∼ 14 ⋅ 10 −6 K −1 at 𝑇 ∼ 800 K [50,54], which is slightly higher than our DFT data of 12 ⋅ 10 −6 K −1 at the same temperature. Overall, our results and the experimental data line up quite well, if the temperature range over which the thermal expansion coefficient was measured, i.e.…”

“…We note that there is a variation in the thermal expansion coefficient values reported by Beck [50] and Cinbiz et al [54], depending on the thermal range over which 𝛼 was averaged. Some of these differences were attributed to the presence of other hydride morphologies (mainly 𝛾-ZrH) than the 𝛿-phase, which impact the thermal expansion [50,54]. To dissolve the other hydrides, high temperature measurements were required.…”

“…Although there is plenty of results from measurements available in the literature, there is significant scatter among the reported data, which makes it highly uncertain. In fact, the reported data for 𝛿-ZrH 𝑥 lies in the range ∼ 3 ⋅ 10 −6 − 30 ⋅ 10 −6 K −1 [49][50][51][52][53][54], which differ by approximately one order of magnitude. Thus, a reliable account of the thermal expansion is necessary for an accurate description of the thermally-induced strain behaviour in hydrides.…”

MARVEL Reactor Fuel Performance Report

“…Microstructure α⸱10 6 [28] (Equation 11) δ-ZrH 1.6 26.54 [33] δ 14.1 [34] δ 2.9 [35] δ+α 9-11 [35] δ+γ 12.7 [35] δ (γ contribution excluded) 14.2 [27] δ (+γ) 6.6-10 [36] δ (at δ+ε) 12.17…”

Methods for accurate high-temperature Sieverts-type hydrogen measurements of metal hydrides

“…Silica or quartz sample cells are typically limited to a maximum hydrogen pressure of less than 3 bar and hydrogen diffusion through the reactor walls is still an issue. Heavy-walled steel SCRs have been used at a temperature of up to 707 °C and a maximum hydrogen pressure of ≃ 50 bar [27] while steel SCRs operating between 700 and 1000 °C were used up to a pressure of ≃ 1.2 bar [29]. A pressure equalising double-walled steel SCR capable of operating at 900 °C and hydrogen pressures of more than 650 bar, constructed by Klostermeier and Frank [28], eliminated the effect of hydrogen diffusion but came at the expense of increased experimental complexity and cost with the SCR still being affected by the hydrogen solubility of the steel.…”