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Yoshida, Hiroyuki; Horiguchi, Naoki; Ono, Ayako; Furuichi, Hajime*; Katono, Kenichi*
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 7 Pages, 2022/08
Horiguchi, Kenichi
Gijutsushi, 30(4), p.8 - 11, 2018/04
The verification activity and training of operation in the Fukushima-Daiichi Nuclear Power Station are more important than another Nuclear Power Station. At the JAEA Naraha Remote Technology Development Center, it has being carried out the development work to apply to the decommissioning work by using the full sized mock up and VR system which is built based on location surveying data of inside the reactor building. It is able to contribute to the decommissioning more reliably and efficiently.
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.
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.
Sugaya, Atsushi; Horiguchi, Kenichi; Tanaka, Kenji; Kobayashi, Kentaro
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 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; 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 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 10g/L or less.
Takano, Masato; Horiguchi, Kenichi; Tanaka, Kenji; Kobayashi, Kentaro
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.
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; Kobayashi, Kentaro
no journal, ,
Tokai Reprocessing Center is developing a cement based encapsulation method to immobilize low level radioactive effluent. Phosphate effluent arising from Solvent Waste Treatment Facility 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 pretreatment trials at small scale executed to ease adverse effect of phosphate.
Iwata, Masayuki*; Shimokawa, Kosuke*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
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.
Horiguchi, Kenichi; Sugaya, Atsushi; Tanaka, Kenji; Akutsu, Shigeru
no journal, ,
no abstracts in English
Iwata, Masayuki*; Shimokawa, Kosuke*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
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*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Okadome, Yoshihiro*; Kobayashi, Atsushi*; Arai, Tsuyoshi*; Iwata, Masayuki*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
Takano, Masato; Horiguchi, Kenichi
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
Okadome, Yoshihiro*; Iwata, Masayuki*; Arai, Tsuyoshi*; Nagayama, Katsuhisa*; Suzuki, Tatsuya*; Horiguchi, Kenichi; Sugaya, Atsushi
no journal, ,
no abstracts in English
