Calculation and measurement of helium generation and solid transmutants inCu-Zn-Ni alloys

A method recently proposed by Garner and Greenwood [1] would allow the sepa ration of the simultaneous and possibly synergistic effects of solid and ga seous transmutation in Cu-Zn-Ni alloys. Copper transmutes primarily to Ni a nd Zn, leading to an accelerated production of helium from the ingrowth of zinc in mixed-spectrum reactors. Adding Zn to Cu alloys eliminates the time required for this ingrowth and leads to accelerated helium rates which are comparable to the well-known effect in Ni. Using a suitable Cu-Zn-Ni alloy matrix in a comparative irradiation of thermal neutron shielded and unshie lded specimens, the separate influences of the solid and gaseous transmutan ts should be distinguishable. To assess the potential of this proposal, it is necessary to show that we can accurately predict the isotopic and elemen tal evolution of these alloys. In the current study, several different Cu-Z n-Ni alloys, irradiated in the HFIR JP-23 experiment, were characterized by measuring of the helium content as well as the solid transmutants. The mea sured values are in good agreement with calculations based on neutron dosim etry, therefore allowing the successful design of the transmutation experim ent proposed by Garner and Greenwood. (C) 1998 Published by Elsevier Scienc e B.V. All rights reserved.