蒸汽发生器传热管破损叠加全船断电事故放射性分析

以严重事故分析程序MELCOR为计算工具,研究了某型船用堆发生蒸汽发生器传热管破损叠加全船断电事故,针对传热管破损所导致的放射性物质向其他舱室的泄漏,着重分析了惰性气体和CsI的释放、迁移、滞留特点及其在舱室内的分布。计算结果表明:二回路蒸汽管道会发生超压失效,氢燃导致堆舱邻舱的超压失效。至计算结束,约占累积总量99.61%的Xe和49.96%的CsI从堆芯释放出来。舱室Ⅰ和Ⅱ内Xe的分布份额分别为38%和18%,CsI的分布份额分别为22.2%和2.7%,CsI主要存在于舱底水池中,且泄漏至舱室Ⅱ的份额微少。本文分析结果可为进一步的源项剂量分析及船内外应急提供依据。

Radioactive Analysis on Accident of SG-tube Rupture Coupled with Whole Ship Blackout

Based on MELCOR which is the severe accident analysis integration program, the accident of SG-tube rupture coupled with whole ship blackout was researched.Considering the release of radioactive material to other cabins in the case of SG-tube rupture, the release, migration, retention and distribution characteristics of the noble gas and CsI were analyzed. The result shows that steam pipe of the secondary loop would be overpressure failure and hydrogen combustion would result in overpressure failure of the adjacent ones of reactor cabin. At the end of the computation, about 99.61% of Xe and 49.96% of CsI in total cumulative amount were released from the reactor core. In cabin Ⅰ and Ⅱ, the distribution fraction of Xe was 38% and 18%, and it was 22.2% and 2.7% for CsI respectively. CsI was mainly resided in the bottom pool of the reactor cabin, and a small amount of the CsI was leaked to the cabinⅡ. The analysis results will provide help for further analysis on the source dose and for emergency inside and outside the ship.