核电厂氚的产生和排放分析

研究核电厂中氚在堆芯和主冷却剂中的产生方式,以及进入环境的途径、形态和排放量,是核电厂辐射环境影响评价非常重要的内容之一。本文通过分析压水堆核电厂中的主冷却剂系统、辅助系统、三废系统和厂房通风系统的运行模式,结合国际上的运行经验参数,研究主冷却剂中的氚排放进入环境大气的途径和形态。研究结果表明:理论计算分析结果与电厂运行经验数据相吻合,氚主要通过燃料棒中的三元裂变,可燃毒物棒中硼的活化以及主冷却剂中硼、锂和氘流经堆芯时的活化产生,主要以液态氚水形式排放,影响气液两相分配份额的主要因素取决于主冷却剂向反应堆厂房和辅助厂房的泄漏率。

Analyses of Generation and Release of Tritium in Nuclear Power Plant

Tritium research including tritium generation in reactor core and in the primary coolant, release pathways, tritium chemical forms and release amount is a very important part of environment assessment of nuclear power plant. Based on the international operation practice, the primary coolant system, auxiliary systems, radwaste system and ventilation system were analysed, and the tritium release pathways and chemical forms were investigated. The results indicate that the theoretic calculation results agree with the nuclear power plant operation data very well. The tritium contained in the primary coolant is mainly produced from the three-fragment fission reaction, boron activation in the burnable poison rods and boron, lithium and deuterium activation when they pass through the core. The released tritium to the environment is mainly in the form of tritiated water and the percentage between the liquid and gaseous of release tritium mainly depends on the leakage rate from the primary coolant to the reactor building and auxiliary building.