船用压水堆核泄漏事故工作舱室辐射场绝对分布研究

Study on the absolute distribution of the radiation field in the work cabins in case of radioactive leakage involving the shipboard pressurized water reactor

目的 建立船用压水堆核泄漏事故工作舱室辐射场实时绝对分布的研究方法.方法 通过分析船用压水堆运行规律、辐射源项与释放机理,研究船用压水堆变工况运行条件下堆芯主要放射性核素积存量计算方法,进而利用核动力船舶内131I探测装置实时监测数据建立工作舱室辐射场实时绝对分布确定方法.结果 利用Matlab软件建立了船用压水堆变工况运行条件下堆芯主要放射性核素积存量以运行功率和运行时间为变量的最小二乘法拟合函数,初步确定了船用压水堆核泄漏事故工作舱室辐射场实时绝对分布确定流程,船用压水堆变工况运行条件下堆芯主要放射性核素积存量与运行功率、运行时间的函数拟合值与真实值的拟合度可达到95％以上.结论 所建立的船用压水堆核泄漏事故工作舱室辐射场实时绝对分布技术方法,可将船上相关装置设置输入接口,并可实现船用压水堆核泄漏事故工作舱室船员剂量即时快速估算,对船用压水堆核泄漏事故应急救援意义重大.

Objective To establish the method of real-time absolute distribution of the radiation field in the work cabins when radioactive leakage occurred involving the shipboard pressurized water reactor （PWR）.Methods By analyzing operating modes of the shipboard PWR,radioactive source items and release mechanism,the calculation method for the determination of cumulative amount of main radionuclides in the PWR-core under variable conditions was investigated.Then,by using the real time monitoring data of the iodine-131 detection devices onboard the nuclear-powered ship,the method of radiation field absolute distribution in the work cabins was established.Results By using Matlab software kit,the least square fitting to the function in the accumulation quantity of the main radionuclides in the reactor core and operating power and running time was thus established,and the procedures for the real-time absolute distribution of the radiation field in the work cabins when radioactive leakage occurred were initially identified.The goodness-of-fit between the fitting value of function for the accumulation quantity of the main radionuclides in the reactor core and operating power and running time,and true fitting value reached over 95％ under variable operating conditions of the shipboard pressurized reactor core.Conclusions The determining procedures for the real-time absolute distribution of the radiation field in the work cabins on shipboard the PWR will facilitate input interface with the related device of the ship,and can help to realize instant and fast dose-estimation of the crew in case of radioactive leak accident.It is of great significance for the emergency rescue of the radioactive leak accident that might occur in the PWR on board the ship.