Outline of decommissioning plan of Tokai Reprocessing Plant

Okano, Masanori; Akiyama, Kazuki; Taguchi, Katsuya; Nagasato, Yoshihiko; Omori, Eiichi

Dekomisshoningu Giho, (57), p.53 - 64, 2018/03

The construction of Tokai Reprocessing Plant (TRP) was initiated in June 1971, and its hot test using spent fuel started in September 1977. Thereafter TRP had been operated to reprocess 1,140 tons of spent fuel for approximately 30 years until May 2007, according to the reprocessing contract with domestic electric power companies. JAEA announced a policy of TRP in report of JAEA reform plan published in September 2014. The policy shows that TRP will shift to a decommissioning stage by economic reasons. Based on the policy, application of approval for TRP decommissioning plan was submitted to Nuclear Regulation Authority (NRA) in June 2017. This plan provides basic guidelines such as procedures for decommissioning and specific activities for risk reduction, and implementation divisions of decommissioning, management of spent fuels and radioactive wastes, decommissioning budget, and decommissioning schedule. The process of TRP decommissioning is planned to continue for approximately 70 years until the release of controlled areas of approximately 30 facilities.

Measurement of Sr and Sr in water accumulated in turbine building at Fukushima Daiichi

Asai, Shiho; Okano, Masanori; Kameo, Yutaka

Hosha Kagaku Nyusu, (25), p.25 - 28, 2012/03

http://www.radiochem.org/rad-nw/rad_nw25.pdf#page=28

no abstracts in English

Measurement of isotopic composition of lanthanides in reprocessing process solutions by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC/ICP-MS)

Okano, Masanori; Jitsukata, Shu*; Kuno, Takehiko; Yamada, Keiji

Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12

Evaluation technology for burnup and generated amount of plutonium by measurement of xenon isotopic ratio in dissolver off-gas at reprocessing facility (Joint research)

Okano, Masanori; Kuno, Takehiko; Takahashi, Ichiro*; Shirozu, Hidetomo; Charlton, W. S.*; Wells, C. A.*; Hemberger, P. H.*; Yamada, Keiji; Sakai, Toshio

JAEA-Technology 2006-055, 38 Pages, 2006/12

JAEA-Technology-2006-055.pdf:3.33MB

The amount of Pu in the spent fuel was evaluated from Xe isotopic ratio in off-gas in reprocessing facility, is related to burnup. Six batches of dissolver off-gas at spent fuel dissolution process were sampled from the main stack in Tokai Reprocessing Plant during BWR fuel reprocessing campaign. Xenon isotopic ratio was determined with GC/MS. Burnup and generated amount of Pu were evaluated with Noble Gas Environmental Monitoring Application code (NOVA), developed by Los Alamos National Laboratory. Inferred burnup evaluated by Xe isotopic measurements and NOVA were in good agreement with those of the declared burnup in the range from -3.8% to 7.1%. Also, the inferred amount of Pu in spent fuel was in good agreed with those of the declared amount of Pu calculated by ORIGEN code in the range from -0.9% to 4.7%. The evaluation technique is applicable for both burnup credit to achieve efficient criticality safety control and a new measurement method for safeguards inspection.

Development of Analysis Method for Plutonium Amount and Burn up by Measurement of Xenon Isotopic Ratio in Dissolver Off-Gas at Reprocessing Facility

Okano, Masanori; Kuno, Takehiko; Charlton, W. S.*; Wells, C. A.*; Hemberger, P. H.*

46th Annual Meeting of the INMM, Final Program, Abstract 352, 0 Pages, 2005/07

According to achieve the International Atomic Energy Agency's safeguards criteria, development of simple and rapid determination method of Pu amount in the spent fuel has been required. It is known that stable xenon isotopes produced with fission reflect spent fuel characteristics (fuel type, burn up, Pu amount). Since dissolver off-gas which is released with dissolution of spent fuel in reprocessing facility, contains most of gaseous fission products, xenon isotopic ratio in dissolver off-gas sampled from the stack would be expected to provide a new measurement method for application to safeguards inspection. We have studied a new technique to evaluate Pu isotopic ratio and its amount in the fuel from Xe isotopic ratio, which is related to burn up. The technique is also applicable for evaluating burn up credit to achieve efficient critical safety control. Six batches of off gas from dissolution process, DOG: Dissolver off gas, were obtained with press pump from the stack in Tokai Reprocessing Plant at BWR fuel (approx. 30GWD/MTU) reprocessing campaign. Xe isotopic ratio was determined with Gas Chromatography- Quadrupole Mass Spectrometer, GC-QMS. Xe concentrations in the DOGs sampled at the stack were 1,000 to 10,000 ppm, which were enough concentrations for determining minor Xe isotopes. We evaluate burn up and Pu amount with NOVA, Noble Gas Environmental Monitoring Application code, developed by Los Alamos National Laboratory. Inferred burn up was realized 94% of confidences level, which is the conventional definition based on the standard deviation of the results. We also calculated Pu amount in the spent fuel by ORIGEN code based on declared burn up. Based on the two different evaluations for Pu amount, we found that there is 7% difference between NOVA and ORIGEN code. It is summarized that there is possibility of developed method being used newly burn up monitoring and safeguards technique.

Determination of Uranium, Curium and Plutonium in the Hulls

Kuno, Takehiko; Okano, Masanori; Sato, Soichi; *; Jitsukata, Shu*

Final Program Abst. P.60, 60 Pages, 2003/00

Evaluation technology for burnup and generated amount of plutonium by measurement of xenon isotopic ratio in dissolver off-gas at reprocessing facility

Okano, Masanori; Kuno, Takehiko; Yamada, Keiji; Sakai, Toshio

no journal, , 

no abstracts in English

Determination of plutonium in insoluble residue at reprocessing facility

Igarashi, Kazuto*; Nemoto, Hirokazu*; Okano, Masanori; Yamada, Keiji; Sakai, Toshio

no journal, , 

no abstracts in English

Determination of plutonium and curium in insoluble residue of spent fuel dissolver solution by alpha spectrometry

Okano, Masanori; Kuno, Takehiko; Nemoto, Hirokazu*; Igarashi, Kazuto*; Yamada, Keiji; Watahiki, Masaru

no journal, , 

no abstracts in English

Dissolution test on the sludge of the dissolver

Sugai, Eiji; Terunuma, Hirotaka; Otani, Takehisa; Hikita, Keiichi; Hatanaka, Akira; Samoto, Hirotaka; Okano, Masanori; Hayashi, Shinichiro

no journal, , 

A dissolution test of the sludge gathered from the dissolver of Tokai Reprocessing Plant (TRP) was performed for the purpose of eliminating of the sludge, which deposited in the dissolver and clogged pipes equipped in the dissolver. In the result, the sludge consisted primarily of ZrMoO(OH)(HO) and was possible to eliminate at the rate of about 80% by using NaOH and HNO reagent which was commonly-used in the PUREX process. From this experimental result, it is thought that the method of using NaOH and HNO reagent is effective method for the elimination of the sludge which deposited in the dissolver.