Tritium release from lithium silicate and lithium aluminate, in-reactor and out-of-reactor

摘要

Considerable technology has developed for production of tritium in metallic target systems. At normal N-Reactor temperatures ((approximately) 300(degrees)C), aluminum-lithium alloys appear to offer a satisfactory system for tritium production. However, reactor safety requirements have generated interest in a target system which will hold the lithium in place at temperatures to 1200(degrees)C. At the same time, gas retention at irradiation temperatures ((approximately)300(degrees)C) must be acceptable, and extraction of the product must be practical. To determine in-reactor gas release characteristics of the silicate and aluminate materials, targets were irradiated in quartz and aluminum capsules. Following irradiation, the gas (condensible and noncondensible fractions) released in-reactor was recovered by drilling the capsules. Subsequently, the targets were recovered and heated in a laboratory vacuum system to investigate characteristics of tritium and helium evolution as a function of temperature. The experimental procedures are discussed briefly, with details in the Appendix. The results of the study are discussed in terms of in-reactor release and later in terms of laboratory extractions.