Development Group for LWR Advanced Technology
Location : JAEA > Nuclear Science & Engineering Center > LWR Key Technology Development Division > Development Group for LWR Advanced Technology

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Research Activities

Fundamental study on LWR advanced technology to contribute to improvement of scientific rationality for regulation standard, safety margin enlargement for design, and Fukushima NPS decommissioning research. Towards improvement of evaluation method for core and fuel/material behaviors under every conditions from normal operation to severe accident, based on mechanism evaluation. Goal is to contribute to improved/enhanced safety performance of LWR.
(1)Fundamental study on fission product behavior
(2)Simulation technology of core degradation behavior
(3)Prediction method of long-term material integrity and characteristics for support to safety and rational LWR decommissioning

MAリサイクルに関する主な研究項目
Main Research Items


Main Activities (click to expand)

Recent Topics

●Chemisorption behavior of Cesium onto stainless steel(Detail

Management of radiation dose control for the workers is of crucial importance in the decommissioning of Fukushima Daiichi Nuclear Power Station (1F). Radioactive cesium (Cs) deposited on the reactor structure is the main radiation source. A part of reactor structure could have reached a high temperature during severe accident, which causes a chemical reaction of Cs with silicon (Si) in stainless steel as a minor component (chemisorption). The critical issue is that the Cs chemisorption behavior is hardly known. Therefore, we have conducted a fundamental study on the Cs chemisorption in order to elucidate its mechanism. Cs chemisorption tests onto stainless steel have been carried out to investigate influencing chemical factors, such as temperature, atmosphere, related elements etc., on the Cs chemisorption behaviors. Hereafter, the influence of such factors on the Cs chemisorption velocity will be modelized so as to contribute to the Cs distribution analysis in 1F each unit.

●Technologies development for the reproductive experiments of fission products chemical behaviors in severe accident conditions(Detail

One of the most important issue for decommissioning work of Fukushima Daiichi Nuclear Power Station is to decide the method of fuel debris removal. In order to proceed the planning, assessing the distribution of cesium (Cs), which is main radiation source, around Primary Containment Vessel is necessary. In addition, knowing its characteristics, such as chemical form and properties, is also required for the evaluation of changes in the distribution over the years. However, the non-steady reactions of Cs with various materials such as other fission products (FPs) and structural material such as control rod material boron and silicon in stainless steel at high temperature region make the accurate evaluation of FP chemical behavior difficult.
    The TeRRa (Test bench for FP Release and tRansport) facility has been specifically designed and built to reproduce and evaluate FP chemical behaviors from the reactor core to the Primary Containment Vessel under a LWR severe accident; release from fuel, transport as vapor species, condensation of vapor, formation and growth of aerosol, and deposition. Continuous FP chemical behaviors during release and transport can be evaluated thanks to high temperature heating up to 2,500 K, which can reproduce the release and chemical reactions of FPs during fuel melting. This specificity of the TeRRa setup is an advantage compared with other setup. Up to now, we confirmed that the TeRRa facility can reproduce the formation and growth of aerosols and the distribution of deposits along the temperature gradient in a severe accident condition using non-radioactive Cs specimen. We will proceed the data acquisition on the FP chemical behaviors by the TeRRa test in various conditions.

●Vapor Pressure Measurement of Cesium Borates(Detail

Boron carbide is used as control material at Fukushima Daiichi Nuclear Power Plants. Cesium is expected to react with the boron and to be transferred to the reactor building in the form of cesium borates. However, there is little thermodynamic data available in estimation of their transfer behavior. Therefore, we have performed vapor pressure measurements of cesium borates to obtain their thermodynamic data.

●Development of Failure Evaluation Methods for the Pressure Vessel Lower Head(Detail

To gain better awareness of the situation within the reactor pressure vessel (RPV) of the Fukushima Daiichi Nuclear Power Station (1F) and improve the current severe accident (SA) analysis codes, e.g. THALES2 developed by JAEA, we are conducting research and development to assess the rupture behavior of the RPV lower head due to relocation of the molten core. In this study, we are developing a coupled analysis method of thermal-hydraulics (TH) and structural analyses, which are to be applied to the behavior of a molten core and to the thermal-elastic-plastic-creep behavior of the structures, respectively. We are also developing methods for evaluating the failure time and locations of the RPV lower head due to creep-deformation.

●The lucture in the internatinal forum commemorating the 30th anniversary of Chernobyl accident(Detail

We participated "Chornobyl's Legacy for the Nuclear Safety of the World" sponsored by National Academy of Sciences of Ukraine. We have made the technical support to the invited lecture "International Community in Search for International Guarantees of the World Nuclear Safety" by the Special Advisor to the JAEA President Sakata. The need for global cooperation for the enhanced nuclear safety was adopted as the official declaration of the forum.
(Forum URL http://icd.kpi.ua/)

Publication List

Journals, Proceedings, Technical Reports

-2018-
M.Kobata, T.Okane, K.Nakajima, E.Suzuki, K.Owada, K.Kobayashi, H.Yamagami, M.Osaka
S.Miwa, G.Ducros, E.Hanus, P.Bottomley, S.Van Winckel, M.Osaka
S.Uesawa, N.Horiguchi, M.Shibata, H.Yoshida
-2017-
F.Di Lemma, K.Nakajima, S.Yamashita, M.Osaka
F.Di Lemma, S.Yamashita, S.Miwa, K.Nakajima, M.Osaka
International Youth Nuclear Congress 2016 (IYNC 2016)
J.Katsuyama, Y.Yamaguchi, Y.Nemoto, Y.Kaji, M.Osaka
24th International Conference on Structural Mechanics in Reactor Technology (SMiRT-24)
Transactions of 24th International Conference on Structural Mechanics in Reactor Technology (SMiRT-24) (USB Flash Drive)
J.Pospisil, Y.Haga, K.Nakajima, N.Ishikawa, I.C\'isa\v{r}ov\'a, N.Tateiwa, E.Yamamoto, T.Yamamura
K.Nakajima, T.Takai, T.Furukawa, M.Osaka
N.Horiguchi, H.Yoshida, S.Uesawa, Y.Abe
日本機械学会第22回動力・エネルギー技術シンポジウム
Dai-22-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (USB Flash Drive)
N.Miyahara, S.Miwa, K.Nakajima, M.Osaka
2017 Water Reactor Fuel Performance Meeting (WRFPM 2017)
Proceedings of 2017 Water Reactor Fuel Performance Meeting (WRFPM 2017) (USB Flash Drive)
S.Miwa, M.Osaka
S.Uesawa, N.Horiguchi, M.Shibata, H.Yoshida
日本機械学会第22回動力・エネルギー技術シンポジウム
Dai-22-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu (USB Flash Drive)
Y.Kaji, J.Katsuyama, Y.Yamaguchi, Y.Nemoto, M.Osaka
2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017)
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM)
-2016-
.Research Team for Fission Product Behavior
A.Yagmur, K.Uchida, K.Ihara, I.Ioka, T.Kikkawa, M.Ono, J.Endo, K.Kashiwagi, T.Nakashima, A.Kirihara, M.Ishida, E.Saito
F.Di Lemma, K.Nakajima, S.Yamashita, M.Osaka
F.Di Lemma, S.Miwa, M.Osaka
I.Ioka, Y.Kuriki, J.Iwatsuki, S.Kubo, J.Katsuyama, Y.Inagaki
K.Nakajima
M.Osaka, S.Miwa, K.Nakajima, F.Di Lemma, C.Suzuki, N.Miyahara, M.Kobata, T.Okane, E.Suzuki
M.Yamamoto, A.Komatsu, T.Sato, J.Nakano, F.Ueno
17th Asian Pacific Corrosion Control Conference (APCCC-17)
Proceeding of 17th Asian Pacific Corrosion Control Conference (APCCC-17) (USB Flash Drive)
N.Horiguchi, H.Yoshida, Y.Abe
N.Horiguchi, H.Yoshida, Y.Nakao, A.Kaneko, Y.Abe
10th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-10)
Proceedings of 10th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-10) (USB Flash Drive)
S.Miwa, F.Di Lemma, K.Nakajima, M.Osaka
Annual Topical Meeting on LWR Fuels with Enhanced Safety and Performance (TopFuel 2016)
Proceedings of Annual Topical Meeting on LWR Fuels with Enhanced Safety and Performance (TopFuel 2016) (USB Flash Drive)
S.Miwa, S.Yamashita, M.Osaka
S.Miwa, S.Yamashita, M.Osaka
T.Okane, M.Kobata, I.Sato, K.Kobayashi, M.Osaka, H.Yamagami
-2015-
C.Kato, T.Sato, J.Nakano, F.Ueno, I.Yamagishi, M.Yamamoto
C.Suzuki, H.Yoshida, D.Shuh, S.Suzuki, T.Yaita
23rd International Conference on Nuclear Engineering (ICONE-23)
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM)
I.Ioka, Y.Kuriki, J.Iwatsuki, S.Kubo, Y.Inagaki
23rd International Conference on Nuclear Engineering (ICONE-23)
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM)
I.Sato, K.Maeda, M.Suto, M.Osaka, T.Usuki, S.Koyama
M.Yamamoto, T.Sato, A.Komatsu, J.Nakano, F.Ueno
European Corrosion Congress 2015 (EUROCORR 2015)
Proceedings of European Corrosion Congress 2015 (EUROCORR 2015) (USB Flash Drive)
N.Horiguchi, H.Yoshida, T.Kanagawa, A.Kaneko, Y.Abe
23rd International Conference on Nuclear Engineering (ICONE-23)
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM)
S.Miwa
S.Miwa, G.Ducros, E.Hanus, P.Bottomley, S.Van Winckel
7th European Review Meeting on Severe Accident Research (ERMSAR 2015)
Proceedings of 7th European Review Meeting on Severe Accident Research (ERMSAR 2015) (Internet)
S.Miwa, M.Osaka, T.Nozaki, T.Arima, K.Idemitsu
Nuclear Materials Conference 2014 (NuMat 2014)
S.Miwa, S.Yamashita, A.Ishimi, M.Osaka, M.Amaya, K.Tanaka, F.Nagase
4th International Symposium on Innovative Nuclear Energy Systems (INES-4)
T.Nishi, K.Nakajima, M.Takano, M.Kurata, Y.Arita
Nuclear Materials Conference 2014 (NuMat 2014)
T.Taguchi, N.Igawa, A.Birumachi, H.Asaoka, S.Miwa, M.Osaka
7th International Symposium on Surface Science (ISSS-7)
T.Takai, K.Nakajima, T.Furukawa
Y.Akutsu, K.Tanaka, M.Osaka
-2014-
O.Fukushima Project Team, O.Fukushima Fuels and Materials Department, T.Oarai Research and Development Center

※You can search and browse research results of our group by JAEA Orignated Papers Searching System(JOPSS)

Member

Group Leader

逢坂 正彦
OSAKA Masahiko

Group Members

中島 邦久
NAKAJIMA Kunihisa
鈴木 知史
SUZUKI Chikashi
三輪 周平
MIWA Shuhei
鈴木 恵理子
SUZUKI Eriko
堀口 直樹
HORIGUCHI Naoki
井岡 郁夫
IOKA Ikuo
宮原 直哉
MIYAHARA Naokya
西岡 俊一郎
NISHIOKA Shunichiro
劉 家占
LIU Jiazhan
ミラジ ファウラ
MIRADJI Faoulat
高田 準太郎
TAKADA Juntaro
江幡 功栄
EBATA Koei
萩谷 幸宏
HAGIYA Yukihiro
寺門 宙
TERAKADO Hiroshi
佐藤 賢太
SATO Kenta
藤本 美知代
FUJIMOTO Michiyo
唐澤 英年
KARASAWA Hidetoshi
モハマド ビンティ アフィカ
MOHAMADO Binti Afiqa

Collaborators

住谷 邦博
SUMIYA Kunihiro
井元 純平
IMOTO Junpei
日高 昭秀
HIDAKA Akihide
山下 真一郎
YAMASHITA Shinichiro
倉田 正輝
KURATA Masaki
加治 芳行
KAJI Yoshiyuki
根本 義之
NEMOTO Yoshiyuki
勝山 仁哉
KATSUYAMA Jinya
岡根 哲夫
OKANE Tetsuo
高瀬 学
TAKASE Gaku
小畠 雅明
KOBATA Masaaki

Contact Infomation

Development Group for LWR Advanced technology
LWR Key Technology Development Division
Nuclear Science & Engineering Center
Nuclear Science Research Institute
Japan Atomic Energy Agency

3st Laboratory building 213-219, Nuclear Science and Engineering Institute

2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan

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