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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.
Akuzawa, Tadashi*; Kim, S.-Y.*; Kubota, Masahiko*; Wu, H.*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki; Arai, Tsuyoshi*
Journal of Radioanalytical and Nuclear Chemistry, 331(12), p.5851 - 5858, 2022/12
Times Cited Count：5 Percentile：52.01(Chemistry, Analytical)Hiraiwa, Kenichi*; Hirai, Kazuhide*; Sano, Tadashi*; Osawa, Hideaki; Sato, Toshinori; Aoyagi, Yoshiaki; Fujita, Tomoo; Aoyagi, Kazuhei; Inagaki, Daisuke*
JAEA-Technology 2015-033, 50 Pages, 2015/11
JAEA-Technology-2015-033.pdf:12.6MB
Japan Atomic Energy Agency (hereinafter referred to as JAEA) has been conducted a geoscientific research and development project at the Mizunami Underground Research Laboratory and the Horonobe Underground Research Laboratory in order to construct scientific and technological basis for geological disposal. As a collaborative research between JAEA and Tokyo Sokki Kenkyujo Co., Ltd. (hereinafter referred to as TML), we focused on the fiber-optic crack detection sensor developed by TML as a method to detect cracks in the support system that may affect the stability of rock cavern during the operation. To verify long-term safety performance of the sensor for decades, "Evaluation test of long-term durability of fiber-optic crack detection sensor and the support system" at the Mizunami Underground Research Laboratory and "Performance evaluation test of fiber-optic crack detection sensor for in-situ crack detection" at the Horonobe Underground Laboratory Research Laboratory were conducted. As the result, we understand that fiber-optic crack detection sensor is applicable measurement method to promptly detect the cracks in the support system.
-ray analysisShozugawa, Katsumi*; Matsuo, Motoyuki*; Sano, Yuji*; Toh, Yosuke; Murakami, Yukihiro*; Furutaka, Kazuyoshi; Koizumi, Mitsuo; Kimura, Atsushi; Hara, Kaoru; Kin, Tadahiro; et al.
Journal of Radioanalytical and Nuclear Chemistry, 291(2), p.341 - 346, 2012/02
Times Cited Count：3 Percentile：22.93(Chemistry, Analytical)Multiple prompt -ray analysis (MPGA), a new quantification method with high energy resolution, was applied to sediments from a marine shallow-water hydrothermal mound. Surface sediments around mounds were collected from the Wakamiko submarine crater located in Kagoshima Bay, southwest Japan, where the hydrothermal system was different from those at other marine shallow-water hydrothermal mounds. All samples were desalted and MPGA measurements were performed for 4,500 s (real time). Event data were obtained using eight CLOVER Ge detectors. We could obtain concentrations of 
S, 
Mn, 
As, 
Gd, 
K, 
Sm, 
Fe, and 
Rb with high sensitivity by MPGA. Furthermore, S, Rb, and Mn have characteristic concentrations only at a mound, suggesting that sediments were sulfated by magmatic fluids at this mound.
Koike, Masato; Namioka, Takeshi*; Gullikson, E. M.*; Harada, Yoshihisa*; Ishikawa, Sadayuki*; Imazono, Takashi*; Mrowka, S.*; Miyata, Noboru; Yanagihara, Mihiro*; Underwood, J. H.*; et al.
Soft X-Ray and EUV Imaging Systems (Proceedings of SPIE Vol.4146), p.163 - 170, 2000/00
no abstracts in English
Masumura, Keisuke*; Akuzawa, Tadashi*; Kida, Fukuka*; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki
no journal, ,
no abstracts in English
Ishizawa, Kenta*; Akuzawa, Tadashi*; Kida, Fukuka*; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki
no journal, ,
no abstracts in English
Sato, Toshinori; Aoyagi, Yoshiaki; Hirai, Kazuhide*; Sato, Hiroshi*; Sano, Tadashi*
no journal, ,
As a part of validation of the technology to ensure safety on the basic development of the engineering technology for deep underground applications, applicability of the optical fiber sensor for crack detection, which developed by Tokyo Sokki Kenkyujo Co.Ltd., is being evaluated as a collaborative research between JAEA and Tokyo Sokki Kenkyujo Co.Ltd. In this study, evaluation of long-term stability of the optical fiber sensor installed in the -300m Stage at the Mizunami Underground Research Laboratory Constriction Site is being conducted.
Hashizume, Shigeru; Sato, Toshinori; Horiuchi, Yasuharu; Sueyoshi, Yoshitoshi*; Sano, Tadashi*; Hirai, Kazuhide*
no journal, ,
no abstracts in English
Horiuchi, Yasuharu; Sato, Toshinori; Sueyoshi, Yoshitoshi*; Sano, Tadashi*; Hirai, Kazuhide*
no journal, ,
no abstracts in English
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.
Sano, Kyohei; Tameta, Yuito; Akuzawa, Tadashi; Akiyama, Kazuki
no journal, ,
JAEA are considering using a ROV and lifters to recovery waste stored in the HASWS wet cell at the TRP. To confirm the feasibility of the recovery method using a ROV, we conducted tests in an environment simulating the storage state. The test results confirmed that tasks required for the waste recovery method using a ROV can be performed for waste in simulating the real environment. In addition, we confirmed that in a dark environment, it is difficult to grasp the position of the cables from the camera inside the cell, so it is necessary to improve the working environment, such as installing a new light source at the penetration.
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.
