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Sakatani, Keiichi*; Nakatani, Takayoshi; Funabashi, Hideyuki
Nihon Genshiryoku Gakkai Wabun Rombunshi, 18(1), P. 43, 2019/03
The article authored by Keiichi Sakatani et al. and titled "Estimation of corrosion rate of Zr-2.5wt%Nb alloy (Fugen pressure tube) under low-temperature, low-oxygen, and high-pH conditions", Journal of the Atomic Energy Society of Japan, Vol.14, No.4, p.261-267 (2015), has been found to have a problem about reliability of the corrosion data acquisition, and thus retracted by the authors.
Sakatani, Keiichi; Nakatani, Takayoshi; Funabashi, Hideyuki
Nihon Genshiryoku Gakkai Wabun Rombunshi, 14(4), p.261 - 267, 2015/12
The safety assessment of the sub-surface disposal system should ensure that calculated dose rate will be lower than the dose rate assigned to the scenario in question over the whole evaluation period. For activated metal wastes which are the reactor structural materials classified as one of the subject wastes, the rate of nuclide elution under the disposal environment is an important parameter in safety assessment. Some reports have shown that nuclides in a metal matrix are released with corrosion congruently. However, the corrosion rate under low temperature, low oxygen and high pH conditions assuming the disposal environment is not reported about Zr-2.5wt%Nb alloy, which is used in the pressure tube of Fugen (ATR). The gas-accumulating type corrosion test on Zr-2.5wt%Nb alloy was conducted in order to obtain corrosion rate. The corrosion rate after 1 month, 3 months, 6 months, 12 months and 24 months was obtained during the test period.
I in the Accumulated radioactive water and processing water of the Fukushima Daiichi Nuclear Power PlantShimada, Asako; Sakatani, Keiichi; Kameo, Yutaka; Takahashi, Kuniaki
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1137 - 1140, 2015/02
Times Cited Count：6 Percentile：45.92(Chemistry, Analytical)Accumulated radioactive water and processing water were sampled from back and forth of the Accumulated radioactive water processing facility (ARWPF) at Fukushima Daiichi Nuclear Power Plant (FDNPP) to estimate the radioactivity of the secondary waste such as zeolite and sludge adsorbed radioactive material. Separation method of I
from the radioactive materials using solid phase extractant, Anion-SR, was developed, and the concentration of I in the accumulated water and processing water was determined by Inductively Coupled Plasma Mass Spectrometry including dynamic reaction cell (DRC-ICP-MS).
Sakatani, Keiichi; Nakamura, Yasuo; Tsuji, Tomoyuki; Nakatani, Takayoshi
JAEA-Data/Code 2014-020, 38 Pages, 2014/11
JAEA-Data-Code-2014-020.pdf:30.04MB
The safety assessment for sub-surface disposal of radioactive wastes should ensure that calculated dose will be lower than the dose assigned to the scenario in question over the whole evaluation period of hundreds of thousands years. We have developed several assessment tools for the safe disposal of radioactive wastes on the GoldSim platform, and calculated doses since JFY 2008. These assessment tools have been improved reflecting the last view of assessment. In addition, we have developed an assessment tool for the gas migration scenario. This report describes concept of assessment model and structure of tool for the gas migration scenario.
Sakatani, Keiichi; Sugaya, Toshikatsu; Nakatani, Takayoshi; Funabashi, Hideyuki
JAEA-Data/Code 2014-008, 53 Pages, 2014/06
JAEA-Data-Code-2014-008.pdf:39.9MB
The safety assessment of the sub-surface disposal system should ensure that calculated dose will be lower than the dose assigned to the scenario in question during the period from now to future. In order to realize the safety disposal, we have developed several assessment tools on the GoldSim platform and calculated doses since 2008, and these assessment tools have been improved reflecting the last view of assessment. This report describes idea of assessment models and structure of assessment tools for land use scenarios.
Haraga, Tomoko; Tobita, Minoru*; Takahashi, Shigemi*; Sakatani, Keiichi; Ishimori, Kenichiro; Takahashi, Kuniaki
JAEA-Data/Code 2014-007, 52 Pages, 2014/06
JAEA-Data-Code-2014-007.pdf:28.47MB
Fugen Nuclear Power Station was shut down and now is under decommissioning. Many radioactivity concentration data of dismantled materials have to be accumulated to calculate the scaling factors of radioactive wastes and verify that the cleared dismantled materials conform to the clearance levels. A simple and rapid radioactivity determination method for radioactive waste samples was developed in Nuclear Cycle Backend Directorate. For the demonstration, the simple and rapid radioactivity determination method was applied to metal samples, which were taken from dismantled pipes of Fugen. This report summarizes the radioactivity data obtained from the analysis of those samples.
Sakatani, Keiichi; Sugaya, Toshikatsu; Nakatani, Takayoshi; Funabashi, Hideyuki
JAEA-Data/Code 2013-015, 63 Pages, 2013/11
JAEA-Data-Code-2013-015.pdf:8.75MB
The safety assessment of the sub-surface disposal system should ensure that calculated dose will be lower than the dose assigned to the scenario in question during the period from now to future. In order to realize the safety disposal, we have developed several assessment tools on the GoldSim platform and calculated doses since 2008, and these assessment tools have been improved reflecting the last view of assessment. This report describes safety functions of the disposal system, idea of nuclide migration, formulas for nuclides migration, formulas of exposure dose and structure of assessment tool for groundwater scenario.
Sakatani, Keiichi; Nakatani, Takayoshi; Funabashi, Hideyuki
JAEA-Technology 2012-034, 20 Pages, 2012/12
JAEA-Technology-2012-034.pdf:10.22MB
We planned the gas-accumulating type corrosion test on Zr-2.5wt%Nb alloy which is used in the pressure tube of Fugen (ATR) in order to obtain long-term corrosion rate data under the low oxygen and alkaline conditions assuming the disposal environment. Before starting the test, we examined the specimen machining method and confirmed the corrosion test conditions.
Inagaki, Yaohiro*; Sakatani, Keiichi*; Yamamura, Yuki*; Mitsui, Seiichiro; Noshita, Kenji*; Miura, Yoshiyuki*; Kanehira, Norio*; Ochi, Eiji*; Mukunoki, Atsushi*; Chiba, Tamotsu*
Dai-7-Kai Saishori, Risaikuru Bukai Semina Tekisuto, p.136 - 137, 2011/01
Conventional static test methods are not appropriate to evaluate glass dissolution behavior at an arbitrarily-fixed condition due to compositional change of the solution with glass dissolution. In this study, we applied a newly-devised micro-channel flow-through test method to measurement of the initial dissolution rates of Japanese simulated waste glasses, JAEA-P0798 and JNFL-KMOC, at arbitrarily-fixed conditions and we evaluated temperature and pH dependence of glass dissolution. The results showed that the initial dissolution rate increased with temperature and had "V-shaped" pH dependence at each temperature.
Sakatani, Keiichi*; Inagaki, Yaohiro*; Makigaki, Hikaru; Idemitsu, Kazuya*; Arima, Tatsumi*; Mitsui, Seiichiro; Noshita, Kenji*
no journal, ,
A new type of flow-through test method using micro-reactor was developed and applied to measurement of dissolution kinetics for a Japanese simulated HLW glass, P0798. By using this method we measured the initial dissolution rate as a function of pH and temperature. The results showed that the initial dissolution rate has "V-shaped" pH dependence at any temperature and Arrhenius-type temperature dependence. Furthermore, consistency of glass dissolution amount between solid and solution analyses demonstrates the reliability of this test method.
Inagaki, Yaohiro*; Sakatani, Keiichi*; Mitsui, Seiichiro; Idemitsu, Kazuya*; Arima, Tatsumi*; Noshita, Kenji*
no journal, ,
Modeling long-term dissolution of HLW glass in geological disposal needs a consistent evaluation of glass dissolution kinetics under conditions of near silica-saturation. The evaluation of the kinetics also needs reliable and precise data obtained under well-constrained experimental conditions for multiple parameters such as pH, solution concentrations of elements and reactive glass surface area. In the present study, therefore, aqueous dissolution tests were performed for a Japanese type of simulated HLW glass, P0798, by using "Micro-channel flow-through test method" as a function of dissolved silica concentration at several constant pHs. The test results showed that the glass matrix dissolution proceeds at certain rates even under conditions of near silica-saturation, and behavior of aluminum can play an important role in the glass dissolution as well as ion-exchange of alkaline elements.
Nakatani, Takayoshi; Sakatani, Keiichi; Funabashi, Hideyuki; Nishimura, Tsutomu*; Tateishi, Tsuyoshi*
no journal, ,
The corrosion test of the Zr-2.5wt%Nb alloy which is a material of the Fugen pressure tube has started for the setup of nuclide leaching rate from this tube which is activated metal waste in sub-surface disposal environment.
Sakatani, Keiichi; Nakatani, Takayoshi; Funabashi, Hideyuki; Nishimura, Tsutomu*; Tateishi, Tsuyoshi*
no journal, ,
We started the gas-accumulating type corrosion test on Zr-2.5wt%Nb alloy in order to obtain long-term corrosion rate data under the low oxygen and alkaline conditions assuming the disposal environment. And we obtained the corrosion rate data after 1 month, 3 months and 6 months during the test period.
Sakatani, Keiichi; Nakatani, Takayoshi; Funabashi, Hideyuki; Nishimura, Tsutomu*; Tateishi, Tsuyoshi*
no journal, ,
We planned the corrosion test on Zr-2.5wt%Nb alloy which is used in the pressure tube of Fugen (ATR) in order to obtain long-term corrosion rate data under the low oxygen and alkaline conditions assuming the disposal environment. We conducted the test and obtained the corrosion rate data after 1, 3, 6 and 12 months during the test period.
Sakatani, Keiichi; Nakatani, Takayoshi; Funabashi, Hideyuki
no journal, ,
We planned the corrosion test on Zr-2.5wt%Nb alloy which is used in the pressure tube of Fugen (ATR) in order to obtain long-term corrosion rate data under the low oxygen and alkaline conditions assuming the disposal environment. We conducted the test and obtained the corrosion rate data after 1, 3, 6, 12 and 24 months during the test period.
