Properties of new-type liquid tritium breeders and advanced liquid blanket design

点击翻译按钮获取中文摘要

Establishment of fusion fuel cycle is essential in order to realize D-T fusion reactor system, in which more amount of tritium should be produced in the blanket than that of tritium consumed for D-T reaction. The research and development for liquid blanket is more delayed than that of solid blanket, though the former one has a potential of charming concept from the point of economic efficiency. In this study, essential data for liquid breeder properties were obtained and some advanced blanket concepts are reviewed by using them. In particular, liquid lithium-tin alloy, the reduction-oxidation control of fluoride molten salt and the property data of other liquid breeders were supplemented in order to compare all the liquid breeder candidates. New liquid blanket concepts were discussed with the data, and the feasibility and the critical issues were clarified.The following tasks were accomplished;(1) Basic properties such as thermal properties, density and phase diagram of lithium-tin liquid alloy were measured. The tritium release properties such as tritium diffusivity and tritium solubility of the alloy were obtained under neutron irradiation at high temperature by using a blanket-simulated system installed in the fast neutron source reactor "YAYOI".(2) Reduction experiments for HF in fluoride molten salt (LiF-BeF_2) were demonstrated using beryllium as a reducing agent dipped in the salt. Compatibility of structural materials with the reduced fluoride molten salt was investigated and the feasibility of this method was confirmed.(3) Development of Er_2O_3 insulating ceramic coating was done.(4) Evaluation of the data obtained in this study and the discussion on the application to the advanced blanket design were carried out.