Release behavior of radionuclides from MOX fuels irradiated in a fast reactor during heating tests

Tanaka, Kosuke; Sato, Isamu*; Onishi, Takashi; Ishikawa, Takashi; Hirosawa, Takashi; Katsuyama, Kozo; Seino, Hiroshi; Ohno, Shuji; Hamada, Hirotsugu; Tokoro, Daishiro*; et al.

Journal of Nuclear Materials, 536, p.152119_1 - 152119_8, 2020/08

https://doi.org/10.1016/j.jnucmat.2020.152199

In order to obtain the release rate coefficients from fuels for fast reactors (FRs), heating tests and the subsequent analyses of the fission products (FPs) and actinides that are released were carried out using samples of uranium-plutonium mixed oxide (MOX) fuel pellets irradiated at the experimental fast reactor Joyo. Three heating tests targeting temperatures of 2773, 2973 and 3173 K were conducted using an FP release behavior test apparatus equipped with a high-frequency induction furnace and solid FP sampling systems consisting of a thermal gradient tube (TGT) and filters. Irradiated fuel pellets were placed into a tungsten crucible, then loaded into the induction furnace. The temperature was raised continuously at a heating rate of 10 K/s to the targeted temperature and maintained for 500 s in a flowing argon gas atmosphere. The FPs and actinides released from the MOX fuels and deposited in the TGT and filters were quantified by gamma-ray spectrometry and inductively coupled plasma mass spectrometry (ICP-MS) analysis. Based on the analysis, the release rates of radionuclides from MOX fuels for FR were obtained and compared with literature data for light water reactor (LWR) fuels. The release rate coefficients of FPs obtained in this study were found to be similar to or lower than the literature values for LWR fuels. It was also found that the release rate coefficient data for actinides were within the range of variation of literature values for LWR fuels.

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.

DNA gyrase of is characterized as Type II bacterial topoisomerase and its activity is differentially regulated by PprA in vitro

Kota, S.*; Rajpurohit, Y. S.*; Charaka, V. K.*; Sato, Katsuya; Narumi, Issey*; Misra, H, S.*

Extremophiles, 20(2), p.195 - 205, 2016/03

https://doi.org/10.1007/s00792-016-0814-1

Breeding of high ethanol producing yeast by screening from mutant library

Ogino, Chiaki*; Kahar, P.*; Lee, J. M.*; Sato, Katsuya; Ono, Yutaka; Kondo, Akihiko*

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 105, 2016/02

https://doi.org/10.11484/jaea-review-2015-022

Screening of cesium-accumulating mutant of radioresistant bacterium by ion beam breeding technology

Sato, Katsuya; Ueda, Ryoshiro*; Hase, Yoshihiro; Narumi, Issey*; Ono, Yutaka

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 100, 2016/02

https://doi.org/10.11484/jaea-review-2015-022

Draft genome sequence of the radioresistant bacterium , isolated from freshwater fish in Japan

Sato, Katsuya; Onodera, Takefumi*; Omoso, Kota*; Takeda-Yano, Kiyoko*; Katayama, Takeshi*; Ono, Yutaka; Narumi, Issey*

Genome Announcements (Internet), 4(1), p.e01631-15_1 - e01631-15_2, 2016/01

https://doi.org/10.1128/genomeA.01631-15

Radiation monitoring using manned helicopter around the Fukushima Daiichi Nuclear Power Station in the fiscal year 2014 (Contract research)

Sanada, Yukihisa; Mori, Airi; Ishizaki, Azusa; Munakata, Masahiro; Nakayama, Shinichi; Nishizawa, Yukiyasu; Urabe, Yoshimi; Nakanishi, Chika; Yamada, Tsutomu; Ishida, Mutsushi; et al.

JAEA-Research 2015-006, 81 Pages, 2015/07

JAEA-Research-2015-006.pdf:22.96MB

By the nuclear disaster of Fukushima Daiichi Nuclear Power Station (NPS), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPP. These results of the aerial radiation monitoring using the manned helicopter in the fiscal 2014 were summarized in the report.

Development of cesium-accumulating bacteria by ion beam breeding technology

Sato, Katsuya; Ueda, Ryoshiro; Hase, Yoshihiro; Narumi, Issey*; Ono, Yutaka

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 117, 2015/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2014-050.pdf#page=149

Genome analysis of high ethyl caproate producing sake yeasts generated by ion beam breeding

Masubuchi, Takashi*; Hyuga, Hirokazu*; Ueda, Ryoshiro; Hayashi, Hidenori*; Ikenaga, Hiroshi*; Sato, Katsuya; Ono, Yutaka

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 123, 2015/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2014-050.pdf#page=155

Genome analysis of the high temperature tolerant mutant of USDA110 generated by ion-beam irradiation

Takeda, Kiyoko*; Sato, Katsuya; Narumi, Issey*; Ono, Yutaka; Otsu, Naoko*; Yokoyama, Tadashi*

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 120, 2015/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2014-050.pdf#page=152