Short review of sodium removal experience in PNC

Since the establishment of the Power Reactor and Nuclear Fuel Development Corporation (PNC), various research work and development have been carried out for the development of sodium cooled fast breeder reactors. Most of the works, especially those related to large scale facilities are done at the O-arai Engineering Center (OEC) of the PNC. 'Sodium Removal' from components or assemblies has been an area with much concern from the beginning of these works. Among the conventional methods, removal by steam, water, alcohol and vacuumization at high temperatures have been done. In 'Joyo', the experimental fast breeder reactor which reached initial criticality in April 1977, sodium removal from the grapples of the fuel handling facility and the fuel assemblies which come out of the reactor are done as routine work during refueling. Furthermore, when maintenance works for components, such as mechanical sodium pumps for the core cooling system, are done, sodium removal will be done in an exclusive maintenance building