Stochastic estimation of radionuclide composition in wastes generated at Fukushima Daiichi Nuclear Power Station using Bayesian inference

Sugiyama, Daisuke*; Nakabayashi, Ryo*; Tanaka, Shingo*; Koma, Yoshikazu; Takahatake, Yoko

Journal of Nuclear Science and Technology, 58(4), p.493 - 506, 2021/04

https://doi.org/10.1080/00223131.2021.1884137

Development of calculation methodology for estimation of radionuclide composition in wastes generated at Fukushima Daiichi Nuclear Power Station

Sugiyama, Daisuke*; Nakabayashi, Ryo*; Koma, Yoshikazu; Takahatake, Yoko; Tsukamoto, Masaki*

Journal of Nuclear Science and Technology, 56(9-10), p.881 - 890, 2019/09

https://doi.org/10.1080/00223131.2019.1595765

Corrosion behaviour of FeCrAl-ODS steels in nitric acid solutions with several temperatures

Takahatake, Yoko; Ambai, Hiromu; Sano, Yuichi; Takeuchi, Masayuki; Koizumi, Kenji; Sakamoto, Kan*; Yamashita, Shinichiro

Proceedings of Annual Topical Meeting on Reactor Fuel Performance (TopFuel 2018) (Internet), 9 Pages, 2018/10

https://euronuclear.org/events/topfuel/topfuel2018/fullpapers/TopFuel2018-A0080-fullpaper.pdf

The corrosion behaviour of FeCrAl-ODS steels for the accident tolerant fuel cladding of LWRs were investigated in nitric acid solutions for the reprocessing process of spent fuels. The corrosion tests were carried out at 60C, 80C and the boiling point of the solutions, and the specimens were then analysed by XPS. The corrosion remarkably progressed at the boiling point, and the highest corrosion rate was 0.22 mm/y. In the oxide film, the atomic concentration of Fe was lower, than that in the base material, and those of Cr and Al were higher. The results show that the corrosion of FeCrAl-ODS steels in hot nitric acid solution is not severe because of the high corrosion resistance of the oxide film formed on the material; hence, the corrosion resistance of the new cladding materials in the dissolution process of spent fuel is acceptable for reprocessing operations.

Effect of flowing water on Sr sorption changes of hydrous sodium titanate

Takahatake, Yoko; Shibata, Atsuhiro; Nomura, Kazunori; Sato, Tsutomu*

Minerals (Internet), 7(12), p.247_1 - 247_13, 2017/12

https://doi.org/10.3390/min7120247

Hydrous sodium titanate (SrTreat) is able to remove radioactive Sr from Radioactive contaminated water at Fukushima Daiichi Nuclear Power station (F1NPS). Knowing the amount of radioactive nuclides in the used SrTreat is important for an effective disposal and deposition of the F1NPS waste. This study investigated changes in the ability of SrTreat to sorb Sr during its use, and to understand the causes of changes in the sorbing. After exposure to a simulated treated water for 99 h, the surface structure of the SrTreat was changed, and the percentage of sorbed Sr and the buffer capacity for protons decreased. When the amount of radioactive nuclides contained in the used SrTreat is calculated from the sorption data of the as received SrTreat.

Analytical data on contaminated water, rubble and other collected at the Fukushima Daiichi Nuclear Power Station

Asami, Makoto*; Takahatake, Yoko; Myodo, Masato; Tobita, Takeshi; Kobayashi, Kiwami; Hayakawa, Misa; Usui, Yuka; Watahiki, Hiromi; Shibata, Atsuhiro; Nomura, Kazunori; et al.

JAEA-Data/Code 2017-001, 78 Pages, 2017/03

JAEA-Data-Code-2017-001.pdf:4.92MB
JAEA-Data-Code-2017-001-appendix(DVD-ROM).zip:818.06MB

At Fukushima Daiichi Nuclear Power Station owned by Tokyo Electric Power Company Holdings, Incorporated (TEPCO), contaminated water (accumulated, treated) secondary waste from water treatment, rubble and soil were collected and analyzed. The data already opened to public was collected as this report. The analytical data reported by TEPCO, Japan Atomic Energy Agency and International Research Institute for Nuclear Decommissioning until the end of March, 2016, was collected. Information on the samples and values of radioactive nuclide concentration and others were tabulated, besides figures, which show change in radioactive nuclide concentration for major nuclides, are contained. And, English translation and the collected data are provided as electric data.

Comparative study of Sr adsorbents for radioactive contaminated water on severe accident

Takahatake, Yoko; Shibata, Atsuhiro; Nomura, Kazunori

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.2099 - 2104, 2015/09

Decontamination of radioactive liquid waste with hexacyanoferrate(II)

Takahatake, Yoko; Watanabe, So; Shibata, Atsuhiro; Nomura, Kazunori; Koma, Yoshikazu

Procedia Chemistry, 7, p.610 - 615, 2012/00

https://doi.org/10.1016/j.proche.2012.10.093

Development of actinides co-extraction system with direct extraction process using supercritical fruid, 14; Direct extraction test of unirradiated MOX fuel

Kaji, Naoya; Kamiya, Masayoshi; Takahatake, Yoko; Oyama, Koichi; Miura, Sachiko; Koyama, Tomozo; Aoki, Kazuo*; Yamada, Seiya*

no journal, , 

A battery of tests using MOX fuel were performed for development of actinides co-extraction system with direct extraction process using supercritical fluid. The condition that was set up based on consideration of the results of the tests under ordinary pressure, and then was made fine adjusted based on the tests with supercritical fruid. As a result, U, Pu and Am were extracted simultaneously. Comparative test confirmed that U, Pu and Am could be also extracted simultaneously with dodecane as a diluent. While the extraction test of unirradiated MOX fuel with simulated FP, U, Pu was extracted with U and Am, and the Pu residue, that was found at the extraction test of irradiated fuel, was not found. As the result of scrubbing and stripping test, it was showed that traditional extraction process design method could be applied to design scrubbing and stripping process with supercritical fluid.

Strontium decontamination from the contaminated water containing seawater by titanium oxide adsorption

Takahatake, Yoko; Watanabe, So; Shibata, Atsuhiro; Nomura, Kazunori; Koma, Yoshikazu; Nakajima, Yasuo

no journal, , 

It was verified whether the adsorbent, which is using in JAEA for Sr decontamination from low level radioactive liquid waste, could apply for contaminated water containing seawater. In contaminated water containing seawater, the Sr adsorption rate of the adsorbent was speedy and Sr adsorption capacity was not influenced by composition of seawater, so the adsorbent can apply to Sr decontamination from contaminated water containing seawater. But it is necessary to increase selectivity of Sr and Ca, because the adsorbent also adsorbs Ca mostly contained in seawater.

-ray irradiation on nickel ferrocyanide bearing cesium

Arai, Yoichi; Watanabe, So; Takahatake, Yoko; Koma, Yoshikazu; Nomura, Kazunori; Nakajima, Yasuo

no journal, , 

no abstracts in English