Radiation protection during the safely shutdown of a nuclear facility

Objective: To reach the goal of the safe shutdown of a certain nuclear facility by scientific and reasonable and radiation protection measurements. Methods: Before carrying out the safe shutdown work, the radioactive source term was investigated, radiation risk during the implement was analyzed according to the investigation result, the process of safe shutdown was designed, and proper radiation protection plan was formalized and implemented. Results: According to the radiation survey of this facility, it was revealed that the major contaminated nuclides were ¹³⁷Cs, ⁹⁰Sr and ²⁴¹Am. The radioactive contamination area was relatively large and the contamination degree was severe. Besides, the gamma radiation and radioactive aerosol were relatively high in working area. The radiation risk of this program was analyzed according to the survey result. Proper work process was followed and good radiation protection was undertaken to ensure the radiation safety of this work. Conclusion: The radiation protection work met the demand of this program, and provided reference for scientific researchers and management departments engaged in nuclear facility decommission work. (authors)