In situ tritium from Li2O and Li2ZrO3 irradiated in a fast neutron flux: BEATRIX-II, Phase 1 and 2

BEATRIX-II was an in situ tritium recovery experiment. This in situ tritium recovery experiment provided data on the performance of Li2O and Li2ZrO3 under irradiation conditions covering a range of sweep gas compositions and temperatures. The experiment consisted of two separate irradiation cycles which in turn included two vented tritium recovery canisters each. Phase 1 operated for 300 Effective Full Power Days (EFPD) while Phase 2 operated for 203 EFPD of irradiation. The tritium recovery behavior of Li2O and Li2ZrO3 was characterized using temperature transients, sweep gas composition changes and reactor power changes to effect changes in the tritium inventory. The high neutron flux level in FFTF resulted in high tritium generation rates which combined with a responsive tritium measurement system allowed detailed observations on the tritium recovery behavior of Li2O and Li2ZrO3. During the course of the experiment a number of observations were made which did not appear consistent with a simplified view of the tritium recovery behavior of these materials. These observations included small negative tritium recovery peaks preceding the typical primary positive peaks; and, for specific temperature ranges, changes in tritium inventory which where opposite to the characteristic expected changes