Dismantling technology for large-scale sodium components used for a long time, 1; Behavior of impurity adhesion to sodium equipment

Shimoyama, Kazuhito ; Hayakawa, Masato; Suzuki, Shigeaki*; Miyakoshi, Hiroyuki; Ara, Kuniaki 

We are conducting dismantling inspection of large-scale sodium component that we have been using in sodium environment for a long time. It was found from the operation history etc. that the sodium compound adhesion behavior on the inner surface of each device exposed to the sodium environment for several decades from the start of use affects sodium purity. In dismantling large sodium equipment, it is important to reduce the residual sodium in the equipment as much as possible, and proposing to carry out high temperature refining operation effective for removal of these attached impurities at the end of plant operation.