Impact assessment for internal flooding in HTTR (High temperature engineering test reactor)

Tochio, Daisuke; Nagasumi, Satoru; Inoi, Hiroyuki; Hamamoto, Shimpei; Ono, Masato; Kobayashi, Shoichi; Uesaka, Takahiro; Watanabe, Shuji; Saito, Kenji

JAEA-Technology 2021-014, 80 Pages, 2021/09

JAEA-Technology-2021-014.pdf:5.87MB

In response to the new regulatory standards established in response to the accident at TEPCO's Fukushima Daiichi Nuclear Power Station in March 2011, measures and impact assessments related to internal flooding at HTTR were carried out. In assessing the impact, considering the characteristics of the high-temperature gas-cooled reactor, flooding due to assumed damage to piping and equipment, flooding due to water discharge from the system installed to prevent the spread of fire, and flooding due to damage to piping and equipment due to an earthquake. The effects of submersion, flooding, and flooding due to steam were evaluated for each of them. The impact of the overflow of liquids containing radioactive materials outside the radiation-controlled area was also evaluated. As a result, it was confirmed that flooding generated at HTTR does not affect the safety function of the reactor facility by taking measures.

Reactor physics experiment in graphite moderation system for HTGR, 1

Fukaya, Yuji; Nakagawa, Shigeaki; Goto, Minoru; Ishitsuka, Etsuo; Kawakami, Satoru; Uesaka, Takahiro; Morita, Keisuke; Sano, Tadafumi*

KURNS Progress Report 2018, P. 148, 2019/08

https://www.rri.kyoto-u.ac.jp/PUB/report/PR/ProgRep2018/ProgRep2018.html

The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment. To achieve the objectives, the reactor core of graphite moderation system named B7/4"G2/8"p8EUNU+3/8"p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In addition, training of operator of HTTR was also performed during the experiments.

Integrity evaluation of removable lid type shielded container

Uesaka, Takahiro; Kozawa, Masachiyo; Matsumoto, Junko; Endo, Masayuki; Kinoshita, Junichi; Suzuki, Takeshi; Suzuki, Hisao; Morishita, Satoru; Sakamoto, Yu

JAEA-Technology 2012-015, 29 Pages, 2012/06

JAEA-Technology-2012-015.pdf:3.22MB

In Japan Atomic Energy Agency Nuclear Science Research Institute waste treatment building No.2 treat intermediate-level solid waste. Solid wastes are reduced in volume by compaction. They are then canned in stainless can, which are subsequently put in 200-liter concrete-lined drums or 1-m concrete containers, filled with concrete. To prepare for disposal in future, be able to make fit with the technical standard of waste package, we were asked to change the lid type shielded container. Therefore due to the change of lid type shielded container, we confirmed integrity of it with evaluation of close volt by drop analysis, evaluation of shielding, and drop test with a prototype model.

JAEA's technical experiences and lessons learned for environmental remediation of Fukushima, 4; Technical supports for local governments

Sudo, Tomoyuki; Ishikawa, Hiroyasu; Uesaka, Takahiro*; Sonoda, Takashi; Ishikawa, Nobuyuki*; Niizato, Tadafumi; Mikake, Shinichiro; Aoki, Isao; Ishizaki, Nobuhiro; Imamura, Hiroaki; et al.

no journal, , 

JAEA is working the decontamination activity for the environmental remediation of Fukushima. In this activity, I support the decontamination activity for local governments to devise a decontamination plan and actually decontaminate. In this report, 1 introduce the technical knowhow for the decontamination activity of a house.