聚变堆氚的环境安全评估

Assessments of Tritium Environmental Safety of Fusion Reactor

对国家863项目聚变实验增殖堆工程概要设计(FEB-E)进行了氚环境安全问题评估。FEB-E是采用液态锂作为包层氚增殖剂。每个包层模块各区之间用隔板隔开,中间通高压氦气冷却,包层第一壁和偏滤器也用氦气冷却。运用自行研制的SWITRIM程序和Sieverts' 定律研究了正常工作状态下和事故状态下可能造成氚的环境污染水平。研究表明,正常工作状态下包层液态锂中的氚分压在10-6～10-8Pa。造成氚环境污染的主要危险来自氚循环回路中的偏滤器子系统的抽出气体泄漏。因此,提高堆芯等离子体燃耗和真空系统设计性能是重要的。

The tritium environmental contamination issues are evaluated for the engineering outline design of the Fusion Experimental Breeder (FEB-E) which has been supported by the 863-high-tech- project in China. The liquid lithium is utilized for the tritium breeder in the blanket of FEB-E. Between two zones of each blanket module, the flowing high-pressure helium gas is used to remove the heat. In addition, the first wall, vacuum chamber and the divertor target are also cooled by the helium gas. Our computer code, SWITRIM, and the Sieverts' law have been applied in the investigation of the potential tritium contamination level under the normal operation circumstances. Results show that the gaseous tritium partial pressure in blanket is within 10-6～10-10 Pa under normal operation. Main hazard results from the tritium leakage of the subsystem of divertor plasma exhaust gas in the tritium cycle loop. Therefore, an elevated plasma burn-up fraction and the performance of the vacuum system design should be emphasized. (下转第585页)