Decommissioning of the A-1 NPP Long-Term Storage Facility

The paper deals with experience, techniques and new applied equipment durig undergoing decommissioning process of the A-1 NPP long-term pool storage and the follow-up decommissioning plan. For rad-waste disposal of the long-term pool storage (where most of the contaminants had remained following the removal of spent fuel) special equipment has been developed, designed, constructed and installed. The purpose of this equipment is the restorage, drainage and fragmentation of cartridges (used as a spent fuel case), as well as treatment of sludge (located at the pool bottom) and of the remaining liquid radwaste. The drainage equipment for cartridges is designed for discharging KCr2 solution from cartridges with spent fuel rods into the handling storage tank in the short-term storage facility and adjustment of the cartridges for railway transport, prior to the liquidation of the spent fuel rod. The equipment ensures full remote visual control of the process and exact monitoring of its technical parameters, including that of the internal nitrogen atmosphere concentration value. Cartridges without fuel and liquid filling are transferred to the equipment for their processing which includes fragmentation into smaller parts, decontamination, filling into drums with their sealed closing and measurement of radioactive dose. For the fragmentation, special shearing equipment is used which leaves the pipe fragment open for the following decontamination. For cleaning the cartridge bottom from radioactive sludge water jet system is used combined with slow speed milling used for preparing the opening for water jet nozzle. The sludge from the cartridge bottom is fixed into ceramic matrix. Nuclear Power Plant JE A-1 (since 1980 in decommissioning) is situated in the locality of Jaslovske´ Bohunice. So far the decommissioning of the Long-term storage was carried out within Stage I of A-1NPP decommissioning. This year the Stage I of decommissioning finished, and the performance of Stage II of decommissioning was started. Decommissioning of the long-term storage facility continues within Stage II of the A-1 NPP decommissioning process.