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Nakagawa, Akinori; Oyokawa, Atsushi; Murakami, Masashi; Yoshida, Yukihiko; Sasaki, Toshiki; Okada, Shota; Nakata, Hisakazu; Sugaya, Toshikatsu; Sakai, Akihiro; Sakamoto, Yoshiaki
JAEA-Technology 2021-006, 186 Pages, 2021/06
JAEA-Technology-2021-006.pdf:54.45MB
Radioactive wastes generated from R&D activities have been stored in Japan Atomic Energy Agency. In order to reduce the risk of taking long time to process legacy wastes, countermeasures for acceleration of waste processing and disposal were studied. Work analysis of waste processing showed bottleneck processes, such as evaluation of radioactivity concentration, segregation of hazardous and combustibles materials. Concerning evaluation of radioactivity concentration, a radiological characterization method using a scaling factor and a nondestructive gamma-ray measurement should be developed. The number of radionuclides that are to be selected for the safety assessment of the trench type disposal facility can decrease using artificial barriers. Hazardous materials, will be identified using records and nondestructive inspection. The waste identified as hazardous will be unpacked and segregated. Preliminary calculations of waste acceptance criteria of hazardous material concentrations were conducted based on environmental standards in groundwater. The total volume of the combustibles will be evaluated using nondestructive inspection. The waste that does not comply with the waste acceptance criteria should be mixed with low combustible material waste such as dismantling concrete waste in order to satisfy the waste acceptance criteria on a disposal facility average. It was estimated that segregation throughput of compressed waste should be increased about 5 times more than conventional method by applying the countermeasures. Further study and technology development will be conducted to realize the plan.
Sugaya, Atsushi; Tanaka, Kenji; Akutsu, Shigeru
Proceedings of International Waste Management Symposia 2011 (WM2011) (CD-ROM), 11 Pages, 2011/02
The main component of the liquid wastes is sodium nitrate. Nitrate ion decomposition technology is under development to conserve a circumference environment of a disposal site. To investigate the methods for decomposing nitrate ion, several small-scale trials were performed using reductants and a catalyst in sodium nitrate solutions. It will be reported that the cement based encapsulation trials to immobilize the sodium carbonate based liquid waste, which was performed under non-radioactive condition at both small and full scale to investigate the optimum cement formulation.
Horiguchi, Kenichi; Sugaya, Atsushi; Saito, Yasuo; Tanaka, Kenji; Akutsu, Shigeru; Hirata, Toshiaki
Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9411_1 - 9411_9, 2009/05
The low-level radioactive Waste treatment Facility (LWTF) was constructed at the Tokai Reprocessing Plant (TRP) and cold test has been carried out since 2006. The waste which is treated in the LWTF is combustible/incombustible solid waste and liquid waste. In the LWTF, The combustible/incombustible solid waste will be incinerated. The liquid waste will be treated by the radio-nuclides removal process subsequently solidified by cement materials. This report describes the essential technologies of the LWTF and results of R&D work for the nitrate-ion decomposition technology for the liquid waste.
Yoshinaka, Kazuyuki; Takano, Yugo*; Kimura, Yukihiko*; Sugaya, Atsushi; Onizawa, Toshikazu
JAEA-Technology 2008-063, 135 Pages, 2008/10
JAEA-Technology-2008-063.pdf:5.88MB
This paper is reported that result of leaching tests for bituminized waste and Waste solidified by epoxy resin, done from 2003 to 2006. We've get precious knowledge and data, as follows. (1) In leaching tests for bituminized waste, it has detected iodine-129 peak, considered difficult too low energy 
to detect. We've get data and knowledge of iodine-129 behavior first. Leached radioactivity for 50 days calculated by peak area was equal for about 40% and 100% of including radioactivity in bituminized waste sample. And we've get data of behavior of nitric acid ion and so on, important to study for disposal, in various condition of sample shape or leaching liquid temperature. (2) In leaching test for waste solidified by epoxy resin, we've get data of behavior of TBP, radionuclides and so on.
spp.)Reyes-Borja, W. O.*; Sotomayor, I.*; Garz
n, I.*; Vera, D.*; Cede
o, M.*; Tanaka, Atsushi; Hase, Yoshihiro; Sekozawa, Yoshihiko*; Sugaya, Sumiko*; Gemma, Hiroshi*
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 89, 2008/03
Sugaya, Atsushi; Horiguchi, Kenichi; Tanaka, Kenji; Kobayashi, Kentaro
Materials Research Society Symposium Proceedings, Vol.1107, p.173 - 179, 2008/00
In Nuclear Fuel Reprocessing Plant, it is necessary to dispose of a large amount of low level radioactive effluent containing nitrate as a major ingredient, safely and economically. Therefore, engineering developments concerning a cement based encapsulation process have been carried out in JAEA. From the viewpoint of disposal cost decrease, a low level radioactive effluent is passed through the nuclide separation process before cementation to concentrate the radioactivity into the minimum volume for conditioning and disposal. Two kinds of effluents are generated as a result of the nuclide separation; Non-radioactive simulants were prepared for each of these waste streams, and used in encapsulation trials to investigate a special slag cement, on a beaker scale and at full scale (200-litres). The results have confirmed that the nitrate effluent, evaporated up to a predetermined density, can be successfully encapsulated at a salt filling rate of 50wt%, to produce a wasteform which satisfies the required conditions. In the slurry effluent, the strength of the product decreased when carbonate concentration was high. However, it was confirmed that the product made at salt filling rate 50wt% satisfied the required conditions, if the carbonate concentration in the effluent was decreased to 10 g/L or less.
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irradiation using carbon ion-beamReyes-Borja, W. O.*; Sotomayor, I.*; Garzn, I.*; Vera, D.*; Cedeo, M.*; Castillo, B.*; Tanaka, Atsushi; Hase, Yoshihiro; Sekozawa, Yoshihiko*; Sugaya, Sumiko*; et al.
Plant Biotechnology, 24(3), p.349 - 353, 2007/06
Times Cited Count：13 Percentile：32.79(Biotechnology & Applied Microbiology)
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reactions for 
=1.5-2.4 GeVZegers, R. G. T.*; Sumihama, Mizuki*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Dat
, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; et al.
Physical Review Letters, 91(9), p.092001_1 - 092001_4, 2003/08
Times Cited Count：128 Percentile：94.67(Physics, Multidisciplinary)no abstracts in English
= +1 Baryon resonance in photoproduction from the neutronNakano, Takashi*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Date, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujiwara, Mamoru; et al.
Physical Review Letters, 91(1), p.012002_1 - 012002_4, 2003/07
Times Cited Count：1013 Percentile：99.84(Physics, Multidisciplinary)no abstracts in English
Iwata, Masayuki*; Shimokawa, Kosuke*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Akutsu, Shigeru
no journal, ,
no abstracts in English
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Kobayashi, Kentaro; Sasaki, Tadashi*
no journal, ,
In Nuclear Fuel Reprocessing Plant, it is necessary to dispose of a large amount of low level radioactive effluent safely and economically. In JAEA engineering developments concerning a cement solidification process have been carried out. The phosphate effluent occurring from solvent waste treatment facility is based on sodium dihydrogen phosphate. The acidity of this effluent (pH 4) requires a pre-treatment process before cement solidification. Phosphate effluent interfere with cementing reactions by retard of reaction rate and loss of strength, because it is combined with calcium that is element of cement material. It reports on the result of Non-radioactive simulant was prepared for the phosphate effluent, and used in cementation trials to investigate a special slag cement, on a beaker scale and at full scale (200-litres).
Sugaya, Atsushi; Horiguchi, Kenichi; Tanaka, Kenji; Akutsu, Shigeru; Yamaguchi, Takashi*
no journal, ,
The chemical species which may have an influence on cement based encapsulation is included in low-radioactive effluent occurring from the Tokai reprocessing plant as a major ingredient or minor spices. In this matter, the results of the encapsulation trials at the 200L size that were carried out to confirm influence of minor spices in the slurry effluent which includes nitric acid as a major ingredient and sodium dihydrogen phosphate in the phosphate effluent is reported.
Sugaya, Atsushi; Horiguchi, Kenichi; Saito, Yasuo; Tanaka, Kenji; Akutsu, Shigeru; Hirata, Toshiaki
no journal, ,
The Low-level radioactive Waste Treatment Facility (LWTF) was constructed at the Tokai Reprocessing Plant and cold testing has been performed since 2006. The aims of this facility are to provide safe, effective and economic treatment of the Waste. The wastes treated in the LWTF are combustible and incombustible solid waste and liquid waste. The problem of burning up incombustible waste is to generate chlorine gas which causes corrosion. The incinerator is made of corrosion resistant metal and uses cooling water to prevent corrosion. The radio-nuclides separation process is newly-introduced for low-level radioactive liquid waste to reduce the deep geological disposal cost. A large amount of nitrate in the liquid waste might cause the environmental pollution. Nitrate ion decomposition technology is under development. A cement based encapsulation method to immobilize those liquid wastes has been developed. The results of these R&D work will be adopted in the LWTF in the near future.
Iwata, Masayuki*; Shimokawa, Kosuke*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Kobayashi, Kentaro; Sasaki, Tadashi*
no journal, ,
no abstracts in English
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Kobayashi, Kentaro; Sasaki, Tadashi*
no journal, ,
In Nuclear Fuel Reprocessing Plant, it is necessary to dispose of a large amount of low level radioactive effluent containing nitrate as a major ingredient, safely and economically. Therefore, engineering developments concerning a cement based encapsulation process have been carried out in JAEA. From the view point of disposal cost decrease, a low level radioactive effluent is passed through the nuclide separation process before cementation to concentrate the radioactivity into the minimum volume for conditioning and disposal. Two kinds of effluents are generated as a result of the nuclide separation; A nitrate effluent of which the principal ingredient is nitrate with a comparatively low radiation level, and; A slurry effluent including several kinds of salts with a comparatively high radiation level. Non-radioactive stimulants were prepared for each of these waste streams, and used in encapsulation trials to investigate special slag cement, on a beaker scale and full scale(200-litres). Furthermore, JAEA has carried out hazardous material judgment for cement products and leaching test of the cement products which encapsulated actual effluent. I will report that result of there development trials.
Okadome, Yoshihiro*; Iwata, Masayuki*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Iwata, Masayuki*; Okadome, Yoshihiro*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Sugaya, Atsushi
no journal, ,
no abstracts in English
