Assessment of potential radiation exposures by uncontrolled recycle or reuse of radioactive scrap metals

With current waste monitoring technology it is reasonable to assume that much of the material designated as low level waste, generated within nuclear facilities, is in fact uncontaminated. A criterion for uncontrolled disposal of low-level radioactive contaminated waste is that the radiation exposure of the public and of each individual caused by this disposal is so low that radiation protection measures need not be taken. The International Atomic Energy Agency (IAEA) suggests an annual effective dose of 10 μSv as a limit for the individual radiation dose and derived the initial control levels of residual radioactivity based on the Publication 30 of the International Commission on Radiological Protection (ICRP). In 1990, new recommendations on radiation protection standards were developed by ICRP to take into account new biological information related to the detriment associated with radiation exposure. Adoption of these recommendations necessitated a revision of the Commissionʹs secondary limits contained in Publication 30. This study summarizes the potential radiation exposure from valuable scrap metal considered for uncontrolled recycle by new ICRP recommendations. Potential exposure pathways to people were analyzed and concentrations leading to an individual dose of 10 μSv/year were calculated for 14 key radionuclides. These potential radiation doses are compared with the results of previous study.