Analysis of Safety Aspects of Disused Sealed Radiation Source Disposal

Abstract

Sealed radiation sources (SRS) are extensively used worldwide in agriculture, industry, medicine and different research areas. If further use of SRS is not envisaged, and the decision is made on declaration of these disused SRSs (DSRS) as radioactive waste (RW), then legislative and regulatory requirements for RW management are fully applicable from that point. Since DSRSs have essential distinctions from other types of RW, in particular, high specific activity, it is critically important to ensure safe management of DSRS, declared as RW, at all stages of their management including disposal. DSRS disposal as RW is the final phase of SRS lifecycle and final stage of their safe and reliable management. In this paper, there are considered safety issues for management of DSRS, declared as RW. Approaches to DSRS disposal recommended by IAEA, advantages and drawbacks of different disposal options for DSRS are analyzed. DSRS disposal needs shall be considered taking into account safety requirements for RW disposal. First, DSRS shall be attributed to specific RW class to address respective disposal needs. This is a challenging issue because the approaches for categorization of SRS and classification of RW are essentially different. DSRS declared as RW may be disposed of either together with other RW in the existing or planned RW disposal facilities, or in the disposal facilities designed and constructed specially for DSRS. Current situation with DSRS management in Ukraine is analyzed. DSRS management strategy in Ukraine envisages their long-term storage in the centralized facility for 50 years with subsequent transfer for disposal. At that, there are neither specified disposal facilities where DSRS will be disposed of, nor established generic waste acceptance criteria for DSRS disposal. Recommendations on further steps for solving challenging issues related to safe disposal of DSRS in Ukraine are provided. Solution of a set of challenging issues related to DSRS management revealed in the paper will promote implementation of comprehensive approach to safe disposal of DSRS in Ukraine.