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Komuro, Michiyasu; Kanazawa, Hiroyuki; Kokusen, Junya; Shimizu, Osamu; Honda, Junichi; Harada, Katsuya; Otobe, Haruyoshi; Nakada, Masami; Inagawa, Jun
JAEA-Technology 2021-042, 197 Pages, 2022/03
JAEA-Technology-2021-042.pdf:16.87MB
Plutonium Research Building No.1 was constructed in 1960 for the purpose of establishing plutonium handling technology and studying its basic physical properties. Radiochemical research, physicochemical research and analytical chemistry regarding solutions and solid plutonium compounds had been doing for the research program in Japan Atomic Energy Agency (JAEA). In 1964, the laboratory building was expanded and started the researching plutonium-uranium mixed fuel and reprocessing of plutonium-based fuel, playing an advanced role in plutonium-related research in Japan. Since then, the research target has been expanded to include transplutonium elements, and it has functioned as a basic research facility for actinides. The laboratory is constructed by concrete structure and it has the second floor, equipped with 15 glove boxes and 4 chemical hoods. Plutonium Research Building No.1 was decided as one of the facilities to be decommissioned by Japan Atomic Energy Agency Reform Plan in September 2014. So far, the contamination survey of the radioactive materials in the controlled area, the decontamination of glove boxes, and the consideration of the equipment dismantling procedure have been performed as planned. The radioisotope and nuclear fuel materials used in the facility have been transfer to the other facilities in JAEA. The decommissioning of the facility is proceeding with the goal of completing by decommissioning the radiation controlled area in 2026. In this report, the details of the decommissioning plan and the past achievements are reported with the several data.
Kokusen, Junya; Akasaka, Shingo*; Shimizu, Osamu; Kanazawa, Hiroyuki; Honda, Junichi; Harada, Katsuya; Okamoto, Hisato
JAEA-Technology 2020-011, 70 Pages, 2020/10
JAEA-Technology-2020-011.pdf:3.37MB
The Uranium Enrichment Laboratory in the Japan Atomic Energy Agency (JAEA) was constructed in 1972 for the purpose of uranium enrichment research. The smoke emitting accident on 1989 and the fire accident on 1997 had been happened in this facility. The research on uranium enrichment was completed in JFY1998. The decommissioning work was started including the transfer of the nuclear fuel material to the other facility in JFY2012. The decommissioning work was completed in JFY2019 which are consisting of removing the hood, dismantlement of wall and ceiling with contamination caused by fire accident. The releasing the controlled area was performed after the confirmation of any contamination is not remained in the target area. The radioactive waste was generated while decommissioning, burnable and non-flammable are 1.7t and 69.5t respectively. The Laboratory will be used as a general facility for cold experiments.
Shiina, Hidenori; Ono, Katsuto; Nishi, Masahiro; Uno, Kiryu; Kanazawa, Hiroyuki; Oi, Ryuichi; Nihei, Yasuo
Dekomisshoningu Giho, (61), p.29 - 38, 2020/03
The Research Hot Laboratory (RHL) in Japan Atomic Energy Agency (JAEA) was constructed in 1961, as the first one in Japan, to perform the examinations of irradiated fuels and materials. RHL consists of 10 heavy concrete cells and 38 lead cells. RHL contributed to research and development program in or out of JAEA for the investigation of irradiation behavior for fuels and nuclear materials. However, RHL is the one of target as the rationalization program for decrepit facilities in former Tokai institute. Therefore the decommissioning works of RHL started on April 2003. The dismantling of 12 lead cells has been progressing since 2010. The dismantling procedure of lead cells was performed in the following order. The peripheral equipment in lead cells were removed and contamination survey of the inner surface of the cells. Then, the backside shield doors were extracted. The lifting frame for the isolation tent was set on the cells. After that, the ceiling plates, isolation walls and lead blocks were removed. The strippable paint was used to remove permeable contamination on the inner surface of structural steel of the cells. The dismantling work will be continued to mention the efficiency of decommissioning works and reduction of radioactive waste with ensuring safety.
Miyai, Hiromitsu; Suzuki, Miho; Kanazawa, Hiroyuki
JAEA-Technology 2016-041, 46 Pages, 2017/03
JAEA-Technology-2016-041.pdf:5.54MB
In the Reactor Fuel Examination Facility (RFEF) of Japan Atomic Energy Agency (JAEA), Post Irradiation Examinations (PIEs) have been carried out for a long time in order to verify the reliability and the safety of the nuclear fuels irradiated in nuclear power plants. Samples for the PIEs are small and have various shapes. In order to facilitate the handling of the samples using a manipulator, the several kinds of jigs have been used for PIEs at RFEF those jigs are usually manufactured by machining process. We tried to make the jigs, which is PLA resin, with 3D printer and instead of machining process for the reduction of the manufacturing time and the improvement of the dimensional accuracy of the jig this time. It became clear that the actual dimensions of the jigs manufactured with 3D printer were roughly smaller at the concave section and larger at the convex section compared with the dimensions of the plan. So it is necessary to make a plan for the jigs after consideration of the characteristic of the 3D printer. The jigs can be applied to SEM observation, because the deposition of carbon film onto the jigs was well. And the jigs can be used to for the metallography, because the jigs were applicable without any harmful effects on polishing and etching processes.
Miyai, Hiromitsu; Suzuki, Miho; Kanazawa, Hiroyuki
Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 4 Pages, 2017/00
In the Reactor Fuel Examination Facility (RFEF) of Japan Atomic Energy Agency (JAEA), Post Irradiation Examinations (PIEs) have been carried out for a long time in order to verify the reliability and the safety of the nuclear fuels irradiated in nuclear power plants. Samples for the PIEs are small and have various shapes. In order to facilitate the handling of the samples using a manipulator, the several kinds of jigs have been used for PIEs at RFEF. Those jigs are usually manufactured by machining process. We tried to make the jigs, which is PLA resin, with 3D printer and instead of machining process for the reduction of the manufacturing time and the improvement of the dimensional accuracy of the jig this time. It became clear that the actual dimensions of the jigs manufactured with 3D printer were roughly smaller at the concave section and larger at the convex section compared with the dimensions of the plan. So it is necessary to make a plan for the jigs after consideration of the characteristic of the 3D printer. The jigs can be applied to SEM observation, because the deposition of carbon film onto the jigs was well. And the jigs can be used to for the metallography, because the jigs were applicable without any harmful effects on polishing and etching processes.
Matsui, Hiroki; Suzuki, Miho; Obata, Hiroki; Kanazawa, Hiroyuki
JAEA-Technology 2014-017, 57 Pages, 2014/06
JAEA-Technology-2014-017.pdf:20.43MB
The Reactor Fuel Examination Facility in JAEA has been used for Post Irradiation Examinations to verify the reliability and safety of the nuclear fuels irradiated in commercial reactors. EPMA (Electron Probe Micro Analyzer) has been utilized for the qualitative analysis of the fission product in the fuel pellet and the detailed observation of the oxide layers formed at the inner and outer surfaces of fuel cladding. Commercial EPMAs were remodeled so that the EPMAs can be applied for radioactive samples. Several shields was set in the EPMA to avoid the 
-rays which radiate from a radioactive sample to the proportional counter in the EPMA. It is important to calculate this shielding performance adequately to maintain the precision of analysis. This report describes the results of re-evaluation of the performance of the shields in the EPMAs in the RFEF by using the Particle and Heavy Ion Transport Code System and the examination results of -ray effect to the X-ray spectrum data by using a radioactive sample.
Koya, Toshio; Nozawa, Yukio; Hanada, Yasushi; Ono, Katsuto; Kanazawa, Hiroyuki; Nihei, Yasuo; Owada, Isao
Dekomisshoningu Giho, (42), p.41 - 48, 2010/09
The Research Hot Laboratory (RHL) in Japan Atomic Energy Agency (JAEA) had been contributed to R&D program for fuels and nuclear materials in or out of JAEA. However, the decommissioning work of RHL has been started on April 2003 as the rationalization program for decrepit facilities in former Tokai institute. This work will be progressing, dismantling the lead cells and decontamination of concrete caves then release in the regulation of controlled area. The partial area of RHL will be used for the central storage of un- irradiated fuel and for temporary storage of radioactive device generated by J-PARC. The 18 lead cells had been dismantled and the preparing work for remained 20 lead cells has been finished including the removal of the applause from the cells, survey of the contamination revel in the lead cells and prediction of radio active waste. The future plan of decommissioning work has been prepared to incarnate the basic vision and dismantling procedure.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Nakata, Masahito; Kanazawa, Hiroyuki; Sagawa, Tamio
JAEA-Conf 2008-010, p.325 - 332, 2008/12
The measurement technique for hydrogen concentration using Backscattered Electron Image analysis (BEI method) had been developed by Studsvik Nuclear AB. The hydride in claddings is identified using BEIs with SEM and the hydrogen concentration is calculated from the area fractions of the hydride in those BEIs. In the RFEF, the sample polishing techniques and image processing procedure for BEI method were improved to measure the hydrogen concentration in the irradiated fuel claddings more precisely. In the previous tests using the un-irradiated fuel claddings, it is confirmed improved BEI method has high reliability. The radial and axial hydrogen concentration profiles of the irradiated fuel claddings were measured with improved BEI method. As the results of these measurements, the local hydrogen concentration could be indicated more precisely with the improved BEI method compared to the other methods for the hydrogen concentration measurement and observation.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
JAEA-Conf 2006-003, p.212 - 221, 2006/05
In the Reactor Fuel Examination Facility (RFEF), a measuring method of hydrogen concentration by backscattered electron image analysis was improved to obtain more local hydrogen concentration data in fuel claddings. The sample preparation and image analysis procedures of this were able to measure hydrogen concentration efficiently and precisely.
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
JAEA-Technology 2006-010, 19 Pages, 2006/03
JAEA-Technology-2006-010.pdf:2.3MB
A measurement technique for hydrogen concentration using Backscattered Electron Image analysis (BEI method) had been developed by Studsvik Nuclear AB, Sweden. The hydrides in claddings are identified using BEIs which are imaged with Scanning Electron Microscope, and the hydrogen concentrations are calculated from the area fractions of the hydrides in the matrix. The BEI method is very useful for the measurement in local hydrogen concentrations of fuel claddings. In the Reactor Fuel Examination Facility, a sample preparation, imaging conditions of SEM and image analysis procedures for the BEI method were improved. In addition, the hydrogen concentrations obtained by the improved BEI method and Hot Vacuum Extraction (HVE) method were compared to confirm the reliability of the improved BEI method. The results showed, the improved BEI method has the same reliability as that of HVE method and can be applied for the Post-Irradiation Examination.
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Journal of Nuclear Materials, 149(1), p.113 - 116, 1987/01
Times Cited Count：6 Percentile：82.02(Materials Science, Multidisciplinary)no abstracts in English
Onozawa, Atsushi; Harada, Akio; Honda, Junichi; Yasuda, Ryo; Nakata, Masahito; Kanazawa, Hiroyuki; Nishino, Yasuharu
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