New interim spent fuel storage facility at Ignalina NPP

Full text: Lithuania has adopted a cautious to the management of spent fuel. Radwaste Management Strategy was issued and approved by the Lithuanian government in February 2002. The Strategy defines a long-term strategy for management of radwaste including spent nuclear fuel. It is intended to use storage facilities for spent nuclear fuel which dual purpose with would be suitable both for long-term storage and transportation. The Strategy says also that it is necessary to carry out the following: the long-term scientific research programme 'Feasibility study on disposal of spent nuclear fuel in Lithuania' shall be prepared and implemented; possibilities to create a deep geological repository in Lithuania for disposal of spent nuclear fuel shall be analyzed; possibilities to create a regional repository using joint efforts of several countries shall be analyzed; possibilities to dispose spent nuclear fuel in other countries shall be analyzed and economic justification of such disposal shall be specified; possibilities to prolong the storage period for spent nuclear fuel for up to 100 and more years shall be scrutinized. At the moment INPP does not have a disposal route for its spent nuclear fuel and used fuel assemblies are taken from the existing ponds after not less then 5-year cooling, loaded into storage casks by type CASTOR/CONSTOR RBMK-1500 and taken into interim storage at a site adjoining the power plant. The capacity of the existing store is for 72 casks. It is possible to extend this capacity to 80 casks. But his store has insufficient capacity to contain all of the fuel that will accumulate in the reactor core and storage ponds prior to and at shutdown of the plant and decommissioning of the reactors cannot start until the removal of fuel from the cores is completed. As no long term disposal or reprocessing route is yet available in Lithuania it is proposed to build an additional interim store. The new interim store will contain all of this remaining fuel for a period at least 50 years under adequate containment and biological shielding for fission product decay prior to final disposal. This store will have the capacity to store all of the spent fuel accumulated up to the closure of Unit 2. These aspects were studied and in accordance with their demands the above mentioned New Interim Spent Fuel Storage at Ignalina NPP shall include following technologies and equipment: to remove spent fuel half-assemblies stored in storage/transfer baskets from the cooling ponds; to remove damaged fuel assemblies including fuel debris from the full-assembly cooling ponds, arrange cutting of the damaged assemblies and insertion of the cut assemblies and debris into suitable storage/transfer baskets; to provide an interim storage facility compliant with specified requirements; to provide a safe means of transport of the spent fuel and fuel debris to the interim storage facility; to place the spent fuel and fuel debris into safe and secure interim storage for a period at least 50 years; to arrange for the safe decontamination and/or disposal of the empty storage/transfer baskets if the fuel is removed from these baskets prior to storage; to inspect and identify/record the assemblies prior to storage; to remove external contamination from the surface of the equipment prior to storage; to provide effluent treatment equipment and systems for the treatment of contaminated solid and liquid waste arising at the processing facility; to monitor the storage conditions (including temperature, radiation, gas leakage from the casks, drain water, environment conditions); to provide security arrangements at the fuel store and connections to the existing utilities, railways and roads including fences where necessary; to provide Interim storage facilities for (approximately) 19,000 spent fuel assemblies. A potential alternative to the interim storage of the spent fuel is reprocessing. At present there are no facilities for the reprocessing of RBMK spent fuel. The design of the interim storage will anyway permit the retrieval of the spent fuel so that reprocessing would remain an option in the future. (author)