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

Abstract

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. Conclusions 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. 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. Key words: Shipboard PWR; Radioactive leak accident; Work cabin; Radiation field; Absolute distribution