In-situ dismantling of the liquid waste storage tank in the decommissioning program of the JRTF

Mimura, Ryuji; Muraguchi, Yoshinori; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05

The JAERI's Reprocessing Test Facility (JRTF) was the first engineering-scale reprocessing facility constructed in Japan. The JRTF was operated from 1968 to 1969 to reprocess spent fuels from the Japan Research Reactor No.3 (JRR-3). As a result of the operation (total 3 runs) by PUREX process, 200 g of highly purified plutonium (Pu) were extracted. In this operation, about 70 m of liquid waste was generated and part of this waste, which including Pu, with relatively high radioactivity, was stored in six large tanks. After shutdown of the facility, the JRTF decommissioning program was started in 1990 to develop decommissioning technologies and to obtain experiences and data on dismantling of fuel cycle facilities. Liquid waste in the tanks was treated from 1982 to 1998. Dismantling of tanks started in 2002. The tanks were installed in narrow concrete cells and inside of the cell was high dose area. Dismantling method for the tank is important factor to decide manpower and time for dismantlement. In this paper, in-situ dismantling of the liquid waste storage tank and its preparation work are discussed.

Results of the environmental radiation monitoring following the accident at the Fukushima Daiichi Nuclear Power Plant; Interim report (Ambient radiation dose rate, radioactivity concentration in the air and radioactivity concentration in the fallout)

Furuta, Sadaaki; Sumiya, Shuichi; Watanabe, Hitoshi; Nakano, Masanao; Imaizumi, Kenji; Takeyasu, Masanori; Nakada, Akira; Fujita, Hiroki; Mizutani, Tomoko; Morisawa, Masato; et al.

JAEA-Review 2011-035, 89 Pages, 2011/08

JAEA-Review-2011-035.pdf:2.97MB

As a correspondence to the accident at the Fukushima Daiichi Nuclear Power Plant, the environmental radiation monitoring was performed at the Nuclear Fuel Cycle Engineering Laboratories, JAEA. This report presented the measurement results of ambient radiation dose rate, radioactivity concentration in the air and radioactivity concentration in fallout and meteorological observation result until May 31, 2011. The ambient radiation dose rate increased, with the peak dose rate of several thousand nGy/h at 7 o'clock in March 15, at 5 o'clock in March 16, and at 4 o'clock in March 21. The variation on the radioactivity concentration in the air and in fallout showed the almost same tendency as that of the dose rate. The concentration ratio of I-131/Cs-137 in the air increased to about 100. The dose was estimated resulting from internal exposure due to inhalation.

Removal of the liquid waste storage tank LV-2 in JRTF, 2; Removal works

Kanayama, Fumihiko; Hagiya, Kazuaki; Sunaoshi, Mizuho; Muraguchi, Yoshinori; Satomi, Shinichi; Nemoto, Koichi; Terunuma, Akihiro; Shiraishi, Kunio; Ito, Shinichi

JAEA-Technology 2011-011, 36 Pages, 2011/06

JAEA-Technology-2011-011.pdf:2.53MB

Dismantling activities of equipments in JAERI's Reprocessing Test Facility (JRTF) started from 1996 as a part of decommissioning of this facility. Removing out of the large liquid waste storage tank LV-2 as a whole tank without cutting in pieces from the annex building B to confirm safety and efficiency of this method started from 2006. After preparatory works, ceiling of LV-2 room was opened, and LV-2 was transferred. Useful data were collected on manpower, radiation control and waste amount through the preparatory works, and work efficiency was analyzed by use of these data.

Examination of fabric of protective clothing suitable for sweltering radiation work; Influence on survey of contamination (MOX) in wet condition with sweat

Horikoshi, Yoshinori; Nemoto, Norio; Kurosawa, Shigeyuki*; Takasaki, Koji; Mizuniwa, Harumi

JAEA-Testing 2008-003, 29 Pages, 2008/04

JAEA-Testing-2008-003.pdf:1.65MB

In the Plutonium Fuel Technical Development Center, protective clothing suitable for sweltering radiation work was examined. Since it worried about the influence of wet protective clothing with sweat on detection of MOX powder contamination, Detection situations, the diffusion of contamination, and the osmosis and penetrability to wet protective clothing were examined about the present fabric and other new fabrics. As a result of examination, it was confirmed that the influence of detection on alpha ray in the wet condition of new fabrics was smaller than the current fabric. This report compiled the result of examination and points in the fabric selection suitable for protective clothing.

Diagnostics system of JT-60U

Sugie, Tatsuo; Hatae, Takaki; Koide, Yoshihiko; Fujita, Takaaki; Kusama, Yoshinori; Nishitani, Takeo; Isayama, Akihiko; Sato, Masayasu; Shinohara, Koji; Asakura, Nobuyuki; et al.

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.482 - 511, 2002/09

https://doi.org/10.13182/FST02-A242

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas has been explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements respectively. In addition, the real-time control experiments of electron density, neutron yield, radiated power and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2 laser interferometer/polarimeter and a CO2 laser collective Thomson scattering system have been developed.

Heating and non-inductive current drive by negative ion based NBI in JT-60U

Oikawa, Toshihiro; Ushigusa, Kenkichi; Forest, C. B.*; Nemoto, Masahiro; Naito, Osamu; Kusama, Yoshinori; Kamada, Yutaka; Tobita, Kenji; Suzuki, Shingo*; Fujita, Takaaki; et al.

Nuclear Fusion, 40(3Y), p.435 - 443, 2000/03

https://doi.org/10.1088/0029-5515/40/3Y/301

no abstracts in English

Recent RF activities on JT-60U

Ikeda, Yoshitaka; Fujita, Takaaki; Hamamatsu, Kiyotaka; Ide, Shunsuke; Imai, Tsuyoshi; Isayama, Akihiko; Iwase, Makoto; Kasugai, Atsushi; Kondoh, Takashi; Kusama, Yoshinori; et al.

AIP Conference Proceedings 485, p.279 - 287, 1999/09

https://doi.org/10.1063/1.59748

no abstracts in English

Charge-exchange measurements of d-d triton distribution functions in high power neutral beam heating on JT-60U

Tchernychev, F. V.*; Kusama, Yoshinori; Nemoto, Masahiro; Morioka, Atsuhiko; Tobita, Kenji; Ishida, Shinichi

Plasma Physics and Controlled Fusion, 41(10), p.1291 - 1301, 1999/00

https://doi.org/10.1088/0741-3335/41/10/306

no abstracts in English

Destabilization of ellipticity-induced Alfven eigenmodes during ICRF heating and stabilization by negative-ion-based neutral beam injection in JT-60U

Kusama, Yoshinori; Fu, G. Y.*; Kramer, G. J.*; Saigusa, Mikio*; Oikawa, Toshihiro; Ozeki, Takahisa; Moriyama, Shinichi; Tchernychev, F. V.*; Nemoto, Masahiro; Kondoh, Takashi; et al.

Plasma Physics and Controlled Fusion, 41(9), p.1167 - 1177, 1999/00

https://doi.org/10.1088/0741-3335/41/9/308

no abstracts in English

Heating and non-inductive current drive by negative-ion based NBI in JT-60U

Oikawa, Toshihiro; Ushigusa, Kenkichi; Forest, C. B.*; Nemoto, Masahiro; Naito, Osamu; Kusama, Yoshinori; Kamada, Yutaka; Tobita, Kenji; Suzuki, Shingo*; Fujita, Takaaki; et al.

Fusion Energy 1998, Vol.2, p.551 - 558, 1998/10

no abstracts in English