Occupational doses involved in a radioactive waste management laboratory

Abstract

The Radioactive Waste Laboratory (RWL) of IPEN-CNEN/SP receives, treats, packs, characterizes and stores institutional radioactive wastes, in their physical forms solid, liquid or gaseous and sealed radioactive sources, with the objective to assure an adequate level of protection to the population and to future generations and the preservation of environment. Since its creation, RWL has already received and treated about one thousand cubic meter of solid waste, eight thousand spent sealed radioactive sources from practices in industry, medicine and research, totaling more than 100 TBq. In addition, fifteen thousand radioactive lightning rods and twenty two thousand radioactive smoke detectors were received. The activities accomplished in RWL, as dismantling of lightning rods, compaction of solid wastes, decontamination of objects, waste characterization, treated waste packages rearrangement, among others, cause risks of intake and/or external exposure of workers. Requirements of radiological safety established in the regulations of the nuclear authority and international recommendations are consolidated in the RWL radioprotection plan in order to ensure the safety and protection of workers. In this paper, it was evaluated if the procedures adopted were in accordance with the requirements established in the radioprotection plan. It was also studied which activities in the waste management had substantial contribution to the occupational doses of the RWL workers in the period from 2001 up to 2006. For that, the radioprotection plan, the operational and safety procedures, the records of workplace monitoring and the individual dose reports were analyzed. It was observed that the highest individual doses resulted from operations of treated waste packages rearrangement in the facility, and none of the workers received doses above the annual limit.