Lithium Oxide Transport and Lithium Ceramic Stability During Actual High Burnup Irradiation

摘要

Because of the high vapor pressure of LiOH and Li sub 2 O at elevated temperatures, it is possible to transport Li sub 2 O from high temperature regions to low temperature regions of a blanket. This phenomena can potentially establish an operating upper temperature limit for blanket design. Laboratory experiments have been conducted with moisture ladened purge gas flow, but in the FUBR-1A experiment transport was observed as the result of actual H sub 2 O and T sub 2 O releases from the Li sub 2 O at temperatures from 500 to 900 deg C. Quantitative measurements of the extent of transfer to colder metal surfaces reveal that it is limited to a few percent and that it is related to the burnup of the Li sub 2 O. Laboratory studies have also forcasted high corrosion rates between Li sub 2 O and structural metals, but postirradiation observations in this experiment revealed that the nickel liner provides excellent resistance to Li sub 2 O attack at high temperatures. The corrosion caused by LiAlO sub 2 , Li sub 2 ZrO sub 3 and Li sub 4 SiO sub 4 were also examined.