St 737 for Tritium Service: An Experimental Evaluation

Aging Effects in Zr(Fe0.5V0.5)2 Tritides

“…To our knowledge, the alloy most similar to Zr(Fe 0.5 V 0.5 ) 2 that has been investigated by neutron diffraction is ZrMn 2 D 3 deuteride [20], which belongs to the same space group P6 3 /mmc and has lattice parameters a = 5.035 Å and c = 8.276 Å, close to those of Zr(Fe 0.5 V 0.5 ) 2 . Moreover, the stoichiometric value of deuteration was found to be 3 ± 0.1 (the value of x s = 6 must not be confused with the correspondent stoichiometric value determined experimentally), which is very close to the value ~3.2 found for Zr(Fe 0.5 V 0.5 ) 2 [1,16]. Evidence was also achieved that on the 17 sites available, only 6 had a finite probability of being occupied.…”

“…The hydrogen data taken from ref. [1] are also plotted for comparison. For both isotopes, no appreciable differences were observed in the equilibrium pressures during the adsorption and desorption cycles.…”

“…where Q = H or T, x Q is the concentration of solute atom in the alloy, as defined in ref. [1], P Q 2 is the equilibrium pressure in Pa and (Ks) Q is the temperature-dependent Sieverts' constant, is illustrated in Figures 7 and 8 for hydrogen and tritium, respectively. Figures 5-8 show a linear relationship for the solubility up to a H/A value of 0.5 and a T/A value of 0.9 at room temperature.…”

“…The intermetallic compound Zr(Fe 0.5 V 0.5 ) 2 (Getter Alloy St 737 by SAES Getters SpA) has long been investigated as a reversible metal hydride for tritium storage in fusion facilities, as well as a chemical converter to reduce HTO and successively recover tritium [1][2][3]. The importance of both aspects, i.e., tritiated water reduction and the tritiding capabilities of the alloy over a long period of time, has been stressed.…”

Purification of hydrogen isotopes using palladium molecular sieve

“…The device developed by this technology was compact and the cost was low. The working temperature was lower (the maximal working temperature is about 473 K), and so the environmental pollution by diffused tritium is lower too [5][6][7][8]. The basic principle of purification is as follows: hydrogen isotopes are absorbed in palladium at a lower temperature (such as 223 K), and impurities such as He, O 2 , N 2 and CO 2 cannot be absorbed.…”