Illustrative Safety Case and Safety Assessment for the Retrieval of Waste from a Historical RADON-Type Facility in the Russian Federation. Annex II

This Annex presents an illustrative example of a safety case for radioactive waste (RW) retrieval operations from a typical historical RADON-type waste storage facility. Specifically, the safety case only considers retrieval of radioactive waste from Vault 1 of the RADON-type facility. This illustrative safety case follows the guidance provided in IAEA Safety Standards Series No. GSG-3, The Safety Case and Safety Assessment for the Predisposal Management of Radioactive Waste, and illustrates the assessment of normal operational and accident dose scenarios using the methodology developed in the framework of the IAEA International Project on Safety Assessment Driving Radioactive Waste Management Solutions (SADRWMS project). Doses arising from normal operation and accident conditions were determined using the Safety Assessment Framework (SAFRAN) software tool (version 2.3.2.7) to demonstrate application of the assessment methodology. The RADON-type facility comprises four concrete storage vaults filled with approximately 185 m³ of miscellaneous low and intermediate level solid wastes and two empty liquid waste storage tanks. The scope of the activities will result in retrieval of all wastes, repackaging and consignment of the items to another processing and storage facility elsewhere off site. This safety case considers a simple and flexible methodology for RW retrieval activities that has been developed using a combination of manual and semi-remote techniques. Retrieval activities are anticipated to take approximately 100 working days. The safety case demonstrates compliance with national and international dose limits and constraints. Results of the safety assessment indicate a maximum dose to the worker of 6.2 mSv under normal operation and 7.0 mSv under accident conditions. The maximum dose to a member of the public under accident conditions is 0.8 μSv, with negligible public dose under normal operation.