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JAEA Reports

Activity median aerodynamic diameter relating to contamination at Plutonium Fuel Research Facility in Oarai Research and Development Center; Particle size analysis for plutonium particles using imaging plate

Takasaki, Koji; Yasumune, Takashi; Hashimoto, Makoto; Maeda, Koji; Kato, Masato; Yoshizawa, Michio; Momose, Takumaro

JAEA-Review 2019-003, 48 Pages, 2019/03

JAEA-Review-2019-003.pdf:3.81MB

June 6, 2017, at Plutonium Fuel Research Facility in Oarai Research and Development Center of JAEA, when five workers were inspecting storage containers containing plutonium and uranium, resin bags in a storage container ruptured, and radioactive dust spread. Though they were wearing a half face mask respirator, they inhaled radioactive materials. In the evaluation of the internal exposure dose, the aerodynamic radioactive median diameter (AMAD) is an important parameter. We measured 14 smear samples and a dust filter paper with imaging plates, and estimated the AMAD by image analysis. As a result of estimating the AMAD, from the 14 smear samples, the AMADs are 4.3 to 11 $$mu$$m or more in the case of nitrate plutonium, and the AMADs are 5.6 to 14 $$mu$$m or more in the case of the oxidized plutonium. Also, from the dust filter paper, the AMAD is 3.0 $$mu$$m or more in the case of nitrate plutonium, and the AMAD is 3.9 $$mu$$m or more in the case of the oxidized plutonium.

Journal Articles

Development of ROV system to explore fuel debris in the Fukushima Daiichi Nuclear Power Plant

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

Progress in Nuclear Science and Technology (Internet), 6, p.199 - 202, 2019/01

As a technology development to investigate the distribution of submerged fuel debris in the primary containment vessel (PCV) of the Fukushima Daiichi Nuclear Power Station, we are conducting development experiments of sonar system to be mounted in a compact ROV. The experiments were conducted in two types of water tanks with different depths, simulating the PCV, using sonar with different sizes, ultrasonic frequencies, and beam scanning method, and simulated fuel debris. As a result, we characterized the shape discrimination performance of the simulated debris, and the noise due to multi-path in narrow closed space.

Journal Articles

Development of a radiological characterization submersible ROV for use at Fukushima Daiichi

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

IEEE Transactions on Nuclear Science, 65(9), p.2565 - 2572, 2018/09

 Percentile:100(Engineering, Electrical & Electronic)

In order to contribute to the development of technology to search fuel debris submerged in water inside the primary containment vessel of the Fukushima Daiichi Nuclear Power Station, we are developing a remotely operated vehicle (ROV) system equipped with a compact radiation detector and sonar. A cerium bromide (CeBr$$_{3}$$) scintillator detector for dose rate monitoring and $$gamma$$ ray spectroscopy was integrated into ROV and experimentally validated with a $$^{137}$$Cs source, both in the conditions of laboratory and submerged. In addition, the ROV combined with the IMAGENEX 831L sonar could characterize the shape and size of a simulated fuel debris at the bottom of the water pool facility.

Journal Articles

Effect of oxidizing metallic ions on corrosion of stainless steel during concentration process simulating High-level Activity Liquid Waste (HALW) concentrator

Irisawa, Eriko; Kato, Chiaki; Kamoshida, Michio*; Hakamatsuka, Yasuyuki*; Ueno, Fumiyoshi; Yamamoto, Masahiro

Proceedings of European Corrosion Congress 2017 (EUROCORR 2017) and 20th ICC & Process Safety Congress 2017 (USB Flash Drive), 9 Pages, 2017/09

Journal Articles

A Remote-operated system to map radiation dose in the Fukushima Daiichi primary containment vessel

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

Proceedings of 5th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA 2017) (USB Flash Drive), 6 Pages, 2017/06

We are developping a submersible ROV system, coupled with radiation detectors aimed at mapping the interior of the reactors at the Fukushima Daiichi Nuclear Power Station. To map the $$gamma$$-ray intensity environment a cerium bromide (CeBr$$_{3}$$) inorganic scintillator detector sensitive to $$gamma$$-rays has been incorporated into the ROV to measure $$gamma$$-ray intensity and identify radioactive isotopes. The ROV is a cylindrical shape with a diameter of about 150 mm, and it have two end caps of five pumps each allowing control of the ROV in 5 degree of freedom. It is possible to directly replace the CeBr$$_{3}$$ detector with a single crystal chemical vapour deposition (CVD) neutron detector with a $$^{6}$$Li convertor foil that is capable of mapping the thermal neutron flux.

Journal Articles

Performance of the H$$_{p}$$(10) and H$$_{p}$$(0.07) measurable electronic pocket dosimeter for $$gamma$$- and $$beta$$-rays

Takahashi, Masa; Sekiguchi, Masato; Miyauchi, Hideaki; Tachibana, Haruo; Yoshizawa, Michio; Kato, Toru*; Yamaguchi, Akihito*

Journal of Nuclear Science and Technology, 45(Suppl.5), p.225 - 228, 2008/06

 Times Cited Count:1 Percentile:87.16(Nuclear Science & Technology)

JAEA Reports

HTTR hydrogen production system structure and main specifications of mock-up test facility (Contract research)

Kato, Michio; Hayashi, Koji; Aita, Hideki; Ohashi, Hirofumi; Sato, Hiroyuki; Inaba, Yoshitomo; Iwatsuki, Jin; Takada, Shoji; Inagaki, Yoshiyuki

JAEA-Technology 2007-022, 209 Pages, 2007/03

JAEA-Technology-2007-022.pdf:14.46MB

The mock-up test facility was fabricated to investigate performance of the steam generator for mitigation of the temperature fluctuation of helium gas and transient behavior of the hydrogen production system for HTTR and to obtain experimental data for verification of a dynamic analysis code. The test facility has an approximate hydrogen production capacity of 120Nm$$^{3}$$/h and the steam reforming process of methane; CH$$_{4}$$+H$$_{2}$$O=3H$$_{2}$$+CO, was used for hydrogen production of the test facility. An electric heater was used as a heat source instead of the reactor in order to heat helium gas up to 880 $$^{circ}$$C (4MPa) at the chemical reactor inlet which is the same temperature as the HTTR hydrogen production system. Fabrication of the test facility was completed in February in 2002, and seven cycle operations were carried out from March in 2002 to December in 2004. This report describes the structure and main specifications of the test facility.

JAEA Reports

Annual report on experimental operations and maintenances of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system in 2004 fiscal year (Contract research)

Hayashi, Koji; Ohashi, Hirofumi; Morisaki, Norihiro; Kato, Michio; Aita, Hideki; Takeda, Tetsuaki; Nishihara, Tetsuo; Inaba, Yoshitomo; Takada, Shoji; Inagaki, Yoshiyuki

JAEA-Technology 2006-013, 73 Pages, 2006/03

JAEA-Technology-2006-013.pdf:6.27MB

This is annual report on the experimental test operations and maintenances of the mock-up test facility with a full-scale reaction tube for the HTTR hydrogen production system in 2004 fiscal year. The improvement work of catalyst dust filter in combustion system was performed in May 2004, and the performance was confirmed. The sixth experimental test operation was performed from June to July 2004. Periodic inspections on boiler equipment and high-pressure gas production facilities were performed from end of July to September 2004. The seventh experimental test operation was performed from October to December 2004 for chemical reaction shutdown test. From the results, a behavior of the helium-gas cooling system, consists of steam generator and radiator, during chemical reaction shutdown was confirmed. This report is summarized with the outline and the results of the test, maintenance works and inspections, and operation records in mentioned above.

JAEA Reports

Annual report on experimental operations and maintenances of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system in 2003 fiscal year (Contract research)

Hayashi, Koji; Morisaki, Norihiro; Ohashi, Hirofumi; Kato, Michio; Aita, Hideki; Takeda, Tetsuaki; Nishihara, Tetsuo; Inaba, Yoshitomo; Takada, Shoji; Inagaki, Yoshiyuki

JAEA-Technology 2006-012, 98 Pages, 2006/03

JAEA-Technology-2006-012.pdf:7.83MB

This is a report on the experimental operations and maintenances of the mock-up test facility with a full-scale reaction tube for the HTTR hydrogen production system in 2003 fiscal year. The fourth and fifth experimental test operations were performed, from May to July and from October to December in 2003, for the following tests; (a)start-up and shutdown operation test, (b)process change test, (c)continuous hydrogen-production test and (d)chemical reaction shutdown test. From the results, a long time-range stability of the hydrogen production system was confirmed, a behavior of the helium-gas cooling system, consists of steam generator and radiator, during chemical reaction shutdown, was understanded, and so on. Periodic inspections on boiler equipment and high-pressure gas production facilities were performed from end of July 2003. This report is summarized on outlines and results of the tests, outlines and results of the periodic inspections, and operation records of the mock-up test facility.

JAEA Reports

Annual report on experimental operations and maintenances of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system in 2002 fiscal year (Contract research)

Hayashi, Koji; Ohashi, Hirofumi; Inaba, Yoshitomo; Kato, Michio; Aita, Hideki; Morisaki, Norihiro; Takeda, Tetsuaki; Nishihara, Tetsuo; Takada, Shoji; Inagaki, Yoshiyuki

JAEA-Technology 2006-011, 132 Pages, 2006/03

JAEA-Technology-2006-011.pdf:9.47MB

This report describes 2002 fiscal-year experimental test operations of the mock-up test facility with a full-scale reaction tube for the HTTR hydrogen production system. The improvement works were performed in May 2002. The second experimental test operation was performed from June 2002 and the performances of the improved parts were confirmed. Periodic inspections on boiler equipment and high-pressure gas production facilities were performed from end of July 2002. The third experimental test operation was performed, from October 2002, for (a)start-up and shutdown test, (b)process change test, (c)chemical reaction shutdown test and (d)characteristics test on steam reformer. It was confirmed that the changes of helium gas temperature, caused at steam reformer, could be mitigated into the target range by the steam generator. Maintenance works of high-pressure gas production facilities were also performed in February 2003. This report is summarized with the outline and the results of the test, maintenance works and inspections, and operation records in mentioned above.

JAEA Reports

Annual report on experimental operation of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system in 2001 fiscal year (Contract research)

Hayashi, Koji; Inagaki, Yoshiyuki; Kato, Michio; Fujisaki, Katsuo*; Aita, Hideki; Takeda, Tetsuaki; Nishihara, Tetsuo; Inaba, Yoshitomo; Ohashi, Hirofumi; Katanishi, Shoji; et al.

JAERI-Tech 2005-032, 46 Pages, 2005/06

JAERI-Tech-2005-032.pdf:4.79MB

This is annual report on the experimental operation of the mock-up test facility with a full-scale reaction tube for the HTTR hydrogen production system in 2001 fiscal year. The first experimental operation was performed during two weeks from March 1, 2002 to March 13, 2002 to test on the thermal hydraulic performance of the steam reformer and also to train the operators. The thermal hydraulic performance test of the steam reformer was performed to evaluate the heat transfer characteristics between helium gas and process gas in the steam reformer. This report is summarized with an overview of the test, the results and its operation records.

JAEA Reports

Heat transfer characteristics evaluation of heat exchangers of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system (Contract research)

Shimizu, Akira; Ohashi, Hirofumi; Kato, Michio; Hayashi, Koji; Aita, Hideki; Nishihara, Tetsuo; Inaba, Yoshitomo; Takada, Shoji; Morisaki, Norihiro; Sakaki, Akihiro*; et al.

JAERI-Tech 2005-031, 174 Pages, 2005/06

JAERI-Tech-2005-031.pdf:20.71MB

Connection of hydrogen production system by steam reforming of methane to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) has been surveyed until now. Mock-up test facility of this steam reforming system with full-scale reaction tube was constructed in FY 2001, and a lot of operational test data on heat exchanges were obtained in these tests.In this report specifications, structures and heat transfer formulae of steam reformer, steam superheater, steam generator, condenser, helium gas cooler, feed gas heater and feed gas superheater were described. Evaluation codes were newly made to evaluate heat transfer characteristics from measured test data. Overall heat-transfer coefficient obtained from the experimental data were compared and evaluated with the prospective value calculated with heat transfer formulae. As a result, heat transfer performance and thermal efficiency of these heat exchangers were confirmed to be appropriate.

JAEA Reports

Improvement works report on mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system (Contract research)

Sakaki, Akihiro*; Kato, Michio; Hayashi, Koji; Fujisaki, Katsuo*; Aita, Hideki; Ohashi, Hirofumi; Takada, Shoji; Shimizu, Akira; Morisaki, Norihiro; Maeda, Yukimasa; et al.

JAERI-Tech 2005-023, 72 Pages, 2005/04

JAERI-Tech-2005-023.pdf:14.86MB

In order to establish the system integration technology to connect a hydrogen production system to a high temperature gas cooled reactor, the mock-up test facility with a full-scale reaction tube for the steam reforming HTTR hydrogen production system was constructed in fiscal year 2001 and its functional test operation was performed in the year. Seven experimental test operations were performed from fiscal year 2001 to 2004. On a period of each test operation, there happened some troubles. For each trouble, the cause was investigated and the countermeasures and the improvement works were performed to succeed the experiments. The tests were successfully achieved according to plan.This report describes the improvement works on the test facility performed from fiscal year 2001 to 2004.

JAEA Reports

Cause investigation and repair of breakage of catalyst dust filter on mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system (Contract research)

Morisaki, Norihiro; Hayashi, Koji; Inagaki, Yoshiyuki; Kato, Michio; Fujisaki, Katsuo*; Maeda, Yukimasa; Mizuno, Sadao*

JAERI-Tech 2005-009, 37 Pages, 2005/03

JAERI-Tech-2005-009.pdf:14.33MB

The breakage of the catalyst dust filter was found at the nozzle flange, which was welded onto the end plate of the filter, by the bubbling test using nitrogen gas of the mock-up model test facility. We investigated the cause of breakage and devised a repairing method. The cause of the breakage was the stress corrosion cracking (SCC) generated from the inside of the filter. The filter was repaired based on the following countermeasures such as reduction of condensed water in the filter, tensile stress and sensitization at welding joints. Furthermore, the inspection was carried out to investigate the structural integrity of the welding joints in the test facility of which structure, material and operating condition were similar to the filter. As the results, it was confirmed that the structural integrity was maintained.

JAEA Reports

Performance test results of mock-up model test facility with a full-scale reaction tube for HTTR hydrogen production system (Contract research)

Inagaki, Yoshiyuki; Hayashi, Koji; Kato, Michio; Fujisaki, Katsuo; Aita, Hideki; Takeda, Tetsuaki; Nishihara, Tetsuo; Inaba, Yoshitomo; Ohashi, Hirofumi; Katanishi, Shoji; et al.

JAERI-Tech 2003-034, 129 Pages, 2003/05

JAERI-Tech-2003-034.pdf:7.62MB

no abstracts in English

JAEA Reports

Performance test results of helium gas circulator of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system (Contract research)

Shimizu, Akira; Kato, Michio; Hayashi, Koji; Fujisaki, Katsuo; Aita, Hideki; Takeda, Tetsuaki; Nishihara, Tetsuo; Katanishi, Shoji; Takada, Shoji; Inaba, Yoshitomo; et al.

JAERI-Tech 2003-033, 105 Pages, 2003/03

JAERI-Tech-2003-033.pdf:8.35MB

no abstracts in English

JAEA Reports

Out-of-pile demonstration test of HTTR hydrogen production system; Structure and fabrication technology of steam reformer (Contract research)

Inagaki, Yoshiyuki; Ouchi, Yoshihiro; Fujisaki, Katsuo; Kato, Michio; ; Hayashi, Koji;

JAERI-Tech 99-074, p.63 - 0, 1999/10

JAERI-Tech-99-074.pdf:3.0MB

no abstracts in English

JAEA Reports

Cause finding experiments and environmental analysis on the accident of the fire and explosion in TRP bituminization facility

Fujine, Sachio; Murata, Mikio; Abe, Hitoshi; Takada, Junichi; Tsukamoto, Michio; Miyata, Teijiro*; Ida, Masaaki*; Watanabe, Makio; Uchiyama, Gunzo; Asakura, Toshihide; et al.

JAERI-Research 99-056, p.278 - 0, 1999/09

JAERI-Research-99-056.pdf:22.73MB

no abstracts in English

Oral presentation

Applicability of electronic pocket dosimeter in $$gamma$$-beta mixed fields

Takahashi, Masa; Sekiguchi, Masato; Tachibana, Haruo; Hoshi, Shintaro; Yoshizawa, Michio; Kato, Toru*; Yamaguchi, Akihito*

no journal, , 

no abstracts in English

Oral presentation

Contamination at Plutonium Fuel Research Facility of Oarai Research and Development Center, 3; Measurement and data aggregation of radiation contamination for workers' dose evaluation

Kato, Yoshinari; Hashimoto, Makoto; Miyauchi, Hideaki; Yasumune, Takashi; Maeda, Eita; Takasaki, Koji; Yoshizawa, Michio; Momose, Takumaro

no journal, , 

no abstracts in English

22 (Records 1-20 displayed on this page)