The Development of non-destructive assay technology for the quantification of nuclear material in high active solid waste; The Simulation modeling of gamma-ray behavior from waste materials using PHITS code

Horiuchi, Masakazu; Sano, Kyohei; Shirafuji, Masaya; Kato, Akane; Watanabe, Kazuki; Tanigawa, Masafumi; Kitao, Takahiko; Maruyama, Hajime

Dai-46-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2025/12

no abstracts in English

Test using ROV and lifter for recovery waste of HASWS wet waste

Sano, Kyohei; Tameta, Yuito; Akuzawa, Tadashi; Kato, Soma; Takano, Yugo*; Akiyama, Kazuki

JAEA-Technology 2024-018, 68 Pages, 2025/02

JAEA-Technology-2024-018.pdf:4.73MB

High Active Solid Waste Storage Facility (HASWS) at the Tokai Reprocessing Plant (TRP) is a facility for storing highly radioactive solid waste generated from the reprocessing operation. Wet cells in HASWS store hull cans that contain fuel cladding tubes (hull) and fuel end pieces remained after the spent nuclear fuel shearing and dissolving, as well as used filters and contaminated equipment. Dry cells in HASWS store analytical waste containers that contain waste jugs and the other waste generated from analytical operation of samples in TRP. Since HASWS does not have waste recovery equipment from the cells, it is considered that recovery equipment to be installed. In the wet cells, methods of recovery wet-stored waste are being considered that utilize a ROV, which has been used in decommissioning in the UK, and a lifter, which is used in the marine industry to float and transport items sinking to the bottom of the sea. To confirm the feasibility of the recovery method that combines the functions of the ROV and the lifter, tests for removing waste were conducted in steps that came closer to the real environment: a "unit test" to confirm the functions required of each of the ROV and the lifter, a "combination test" to combine the ROV and the lifter to move waste underwater, and a "comprehensive test" to retrieve waste in an environment simulating the hull storage facility. Through this test, the ROV and the lifter were able to perform a series of tasks required to recovery waste - cutting the wires attached to the waste, attaching a lifter to the waste, moving the waste to under the opening, and attaching the recovery device to the moved waste - in series, confirming the feasibility of the method for recovery wet-stored waste using the ROV and the lifter.

Study of recovery waste from High Active Solid Waste Storage (HASWS) at Tokai Reprocessing Plant, 7; Improvements to the ROV's umbilical, waste-grasping device, and hook

Tameta, Yuito; Sano, Kyohei; Yamamoto, Masahiko; Akiyama, Kazuki

no journal, , 

For decommissioning of HASWS at TRP, use of a remotely operated vehicle (ROV) and two types of lifters (grab-type and hook-type) is considered for retrieval of waste stored in a wet cell. The previous study evaluated feasibility of the waste retrieval method, and identified need for improvements to components such as the ROV's umbilical. In this study, enhancements were made to the ROV's umbilical, waste-grasping device and hook. Data were also collected to assess improvements in operability. Results demonstrated that attaching a float to the rear section of the umbilical improved ROV's posture stability, while extending the grab tip enhanced grasping stability. Furthermore, modifying the hook ring size improved ring accessibility.

Study of recovery waste from the High Active Solid Waste Storage (HASWS) at Tokai Reprocessing Plant, 1; Outline of study on HASWS and retrieval equipment

Ito, Satoshi; Sano, Kyohei; Tameta, Yuito; Akiyama, Kazuki

no journal, , 

The High Active Solid Waste store HASWS of Tokai Reprocessing Plant. HASWS don't have a equipment to retrieve the High Active Solid Waste. Therefore, I examined the Using remotely machine at decommissioning of domestic and international. In the technical investigation, I investigated the machine and others which could perform work of (1)-(3). (1) Cutting work of the wire attached to Hull Can. (2) Moving work of Hull Can. (3) Attach the hoisting accessory work of Hull Can. I compared the extracting machine and others. As a result, I chosed the Remotely operated Vehicle And underwater buoyancy.

Development of titanate adsorbent with silica gel support, 1; Column property of adsorbent and Sr adsorption ability

Takahatake, Yoko; Shibata, Atsuhiro; Koma, Yoshikazu; Nakajima, Yasuo; Sano, Kyohei*; Arai, Tsuyoshi*; Hashimoto, Jun*; Kubo, Kaname*; Kaneko, Masashi*

no journal, , 

no abstracts in English

Study of recovery waste from High Active Solid Waste Storage (HASWS) at Tokai Reprocessing Plant, 4; Combination test of ROV and lifter (grab type) (Hull can)

Tameta, Yuito; Sano, Kyohei; Akuzawa, Tadashi; Akiyama, Kazuki

no journal, , 

For the decommissioning of HASWS at TRP, we are considering using a ROV and a lifter to retrieve waste stored in the wet cell. We are considering using a lifter (grab type) to retrieve hull cans that are difficult to move with the ROV and the lifter (hook type), and conducted a mock-up test to confirm the feasibility of moving hull cans by the ROV and the lifter (grab type). Through the test, we confirmed that the hull cans placed in various positions in the mock-up facility could be moved by the ROV and the lifter (grab type). We are also conducting further studies on grabs suitable for gripping hull cans for safer and more reliable retrieval of the hull cans.

Study of recovery waste from High Active Solid Waste Storage (HASWS) at Tokai Reprocessing Plant, 5; Combination test of underwater ROV and underwater lifter (grab type)

Akuzawa, Tadashi; Tameta, Yuito; Sano, Kyohei; Akiyama, Kazuki

no journal, , 

In preparation for the decommissioning of the HASWS, we are considering using an underwater ROV and a submersible lifter (grab type) to remove hull cans, stainless steel filters and stirrers. In this case, to confirm the feasibility of this method, we placed simulated filters and contaminated equipment in various positions in a mock-up facility simulating a wet cell and conducted a test to move them using an underwater ROV and a submersible lifter (grab type). As a result of the test, we confirmed that in all positions, the filters and contaminated equipment could be grasped and floated by the underwater lifter (grab type) and then moved by the underwater ROV.

Column separation experiments with TODGA/SiO-P adsorbent under irradiation condition

Watanabe, So; Ogawa, Tsuyoshi; Nomura, Kazunori; Koma, Yoshikazu; Arai, Tsuyoshi*; Sano, Kyohei*

no journal, , 

no abstracts in English

Study of recovery waste from High Active Solid Waste Storage (HASWS) at Tokai Reprocessing Plant, 2; Study of underwater ROV

Sano, Kyohei; Tameta, Yuito; Ito, Satoshi; Akiyama, Kazuki

no journal, , 

Toward the decommissioning of HASWS in Tokai Reprocessing Plant, we are developing equipment for recovery waste from wet storage. So far, after conducting surveys and operability confirmations of ROVs that have been used for decommissioning in the UK, we have conducted mock-up trials using an ROV tester. In the mock-up trial, simulated waste was placed in various postures and orientations in a mock-up facility simulating the HASWS. We confirmed that the ROV could cut the wires attached to the waste, that the waste could be moved using the underwater ROV and buoyancy, and that the ROV could attach hanging tools to the waste. A result was obtained regarding the removal of waste using an underwater ROV, etc., so I will report it.