Cement based encapsulation experiments for low-radioactive liquid waste at Tokai Reprocessing Plant

Sugaya, Atsushi; Tanaka, Kenji; Akutsu, Shigeru

Proceedings of International Waste Management Symposia 2011 (WM2011) (CD-ROM), 11 Pages, 2011/02

https://www.wmsym.org/archives/2011/papers/11078.pdf

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.

Leaching test of bituminized waste and waste solidified by epoxy resin

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.

Cement based encapsulation trials for low-level radioactive effluent containing nitrate salts

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.

Beam-palarization asymmetries for the (,) and (,) reactions for =1.5-2.4 GeV

Zegers, 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

https://doi.org/10.1103/PhysRevLett.91.092001

no abstracts in English

Cement based encapsulation experiment for low radioactive effluent that contains nitrate

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.

Development of treatment for low radioactive effluent in Tokai Reprocessing Plant, 1; Cement solidification process

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.

Development of treatment for low radioactive effluent in Tokai Reprocessing Plant, 4; Calcium hydroxide based pretreatment experiment for phosphate effluent

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.

Development of treatment for low radioactive effluent in Tokai Reprocessing Plant, 6; Cement based encapsulation experiments for low-radioactive phosphate effluent

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.

Development of treatment for low radioactive effluent in Tokai Reprocessing Plant, 8; Applicability of the catalyst for practical use in sodium nitrate decomposition

Takano, Masato; Sugaya, Atsushi; Tanaka, Kenji; Akutsu, Shigeru; Egami, Hikari*

no journal, , 

no abstracts in English

Development of new treatment process for low level radioactive waste at Tokai Reprocessing Plant

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.