福島第一原発炉内構造物解体に向けたAWJ切断工法の適用可能性検討; 溶融燃料デブリ模擬材の切断可能性および切断状況判定

Applicability of AWJ technique for dismantling reactor of the Fukushima Daiichi Nuclear Power Station; Cutting test of imitation of fuel debris and optimization of the cutting condition

丸山 信一郎*; 綿谷 聡*

Maruyama, Shinichiro*; Watatani, Satoshi*

福島第一原子力発電所(1F)の炉内構造物は、スリーマイル島原子力発電所2号機の知見から溶融燃料と混在した複雑狭隘な状態となっていると想定される。このような想定から、炉内構造物を安全かつ合理的に切断解体する方法として、アブレイシブウォータージェット(AWJ)切断工法を候補に適用可能性の検討を行った。検討にあたり、AWJ切断工法が保有している課題(溶融燃料デブリ模擬材切断、切断可否判定)について試験を実施した。結果、AWJ切断工法が1Fの炉内構造物の解体方法の候補と成り得ることを確認した。

Based on findings made during recovery works that followed the accident at Three Mile Island Station2, we assume that the reactor internals at the Fukushima Daiichi Nuclear Power Station (1F) have intermixed with melted fuel and confined in limited spaces, they are likely to have complex geometries. Accordingly, abrasive water jet (AWJ) cutting method is considered to be a candidate technique that can be safely and reasonably used for cutting and removing reactor internals. We conducted tests to examine the potential of this technique. We have test for solving the problems of this technique. They are using imitation of fuel debris and optimization of the cutting condition. Based on the results, we confirmed the plan for some of the associated issues, and that AWJ cutting method would be assumed as a candidate technique for removing reactor internals.