Experience From Safety Assessment of the Existing Storage Facility for Solid Radwaste at Ignalina NPP

There is only one nuclear power plant in Lithuania — Ignalina NPP (INPP). The INPP operates two similar units with present power level of about 1250 MW(e) each. They were commissioned (first grid connection) in 1983 and 1987 respectively and provide approximately 70–80 per cent of the electricity produced in Lithuania. From the beginning of INPP operation all power plant generated solid radwaste is collected and stored in the solid radwaste facility that is located in INPP sanitary protected area. The storage facility for solid radwaste at INPP consists of four above ground buildings, namely buildings No. 155, No. 155/1, No. 157 and No. 157/1. This facility is Soviet type facility designed for the interim storage of low and intermediate level radwaste arising as a consequence of operation of NPP. The institutional waste from industry, hospitals etc., including sealed sources as well, has been stored in this facility from 1990. At present this radioactive waste storage facility is still not licensed but SAR is prepared and licensing process is going on. The paper provides information on INPP solid radwaste storage facility and discusses problems met during the safety assessment of this facility: lack of the information on the inventory data, lack of design data for the buildings etc. Modeling results of the structural analysis, radiological data, shielding analysis and proposals to improve the safety of the facility also are discussed.