Irradiation of lithium-based ceramics for fusion blanket application

Unvented CREATE tests have shown that, under reducing conditions, most of the tritium (greater than 70%) is released from LiA102 and Li20 as HT or T2; the balance as HTO or T20. Residual tritium is very small, less than 0.02%. Varying the sweep gas composition has a dramatic effect on the form of tritium released. With a quartz extraction tube during post-irradiation heating, a He sweep gas results in 10-30% release as HT or T2; with a He-1%H2 sweep gas, greater than 60% release as HT is achieved. The effect of extraction tube material is also significant. Using pure He sweep gas, a quartz extraction tube results in 10-30% release as HT or T2; stainless steel produces 80-95% as HT or T2. Chalk River and CEA (Saclay) - fabricated LiA102 behaved similarly to that from ANL in these tests. The first vented test at Chalk River, CRITIC-I, planned for 1986/87, will examine ANL-fabricated Li20, 0.3 wt% Li-6, 30 mm ID, 40 mm OD annular pellets, in a six-month irradiation at 670-1170 K, varying the sweep gas, with on-line HT-HTO measurement