Technology development to evaluate dose rate distribution and to search for fuel debris submerged in water for decommissioning of Fukushima Daiichi Nuclear Power Station, 9; Tank tests of ROVs to map the debris in the primary containment vessel

Kamada, So*; Kato, Michio*; Nishimura, Kazuya*; Nancekievill, M.*; Jones, A. R.*; Lennox, B.*; Joyce, M. J.*; Okumura, Keisuke ; Katakura, Junichi*

As a part of technology development related to fuel debris exploration technology in the reactor containment vessel, demonstration tests of an remotely operated vehicle (ROV) for investigating the distribution and surface condition of submerged fuel debris were carried out by using the test water tank of Naraha Remote Technology Development Center of Japan Atomic Energy Agency and using the TRIGA Mark II research reactor of Jozef Stefan Institute of Slovenia. In the demonstration test, we confirmed the cooperation with the acoustic exploration device, the performance of the ROV positioning system, the operation in the reactor pool, and showed that it is possible to display 3D image of the shape of simulated fuel debris.