Chemical form analysis of reaction products in Cs-adsorption on stainless steel by means of HAXPES and SEM/EDX

Kobata, Masaaki; Okane, Tetsuo; Nakajima, Kunihisa; Suzuki, Eriko; Owada, Kenji; Kobayashi, Keisuke*; Yamagami, Hiroshi; Osaka, Masahiko

Journal of Nuclear Materials, 498, p.387 - 394, 2018/01

https://doi.org/10.1016/j.jnucmat.2017.10.035

In this study, for the understandings of Cesium (Cs) adsorption behavior on structure materials in severe accidents at a light water nuclear reactor, the chemical state of Cs and its distribution on the surface of SUS304 stainless steel (SS) with different Si concentration were investigated by hard X-ray photoelectron spectroscopy (HAXPES) and scanning electron microscope / energy dispersive X-ray spectroscopy (SEM/EDX). As a result, it was found that Cs is selectively adsorbed at the site where Si distributes with high concentration. CsFeSiO is a dominant Cs products in the case of low Si content, mainly formed, while CsSiO and CsSiO are formed in addition to CsFeSiO in the case of high Si content. The chemical forms of the Cs compounds produced in the adsorption process on the SS surface has a close correlation with the concentration and chemical states of Si originally included in SS.

Results and progress of fundamental research on fission product chemistry; Progress report in 2015

Osaka, Masahiko; Miwa, Shuhei; Nakajima, Kunihisa; Di Lemma, F. G.*; Suzuki, Chikashi; Miyahara, Naoya; Kobata, Masaaki; Okane, Tetsuo; Suzuki, Eriko

JAEA-Review 2016-026, 32 Pages, 2016/12

JAEA-Review-2016-026.pdf:6.18MB

A fundamental research program on fission product (FP) chemistry has started since 2012 for the purpose of establishment of a FP chemistry database in each region of LWR under severe accident and improvement of FP chemical models based on the database. Research outputs are reflected as fundamental knowledge to both the research and development of decommissioning of Fukushima Daiichi Nuclear Power Station (1F) and enhancement of LWR safety. Four research items have thus been established considering the specific issues of 1F and the priority in the source term research area, as follows: effects of boron (B) release kinetics and thermal-hydraulic conditions on FP behavior, cesium (Cs) chemisorption and reactions with structural materials, enlargement of a thermodynamic and thermophysical properties database for FP compounds and development of experimental and analytical techniques for the reproduction of FP behavior and for direct measurement methods of chemical form of FP compounds. In this report, the research results and progress for the year 2015 are described. The main accomplishment was the installation of a reproductive test facility for FP release and transport behavior. Moreover, basic knowledge about the Cs chemisorption behavior was also obtained. In addition to the four research items, a further research item is being considered for deeper interpretation of FP behavior by the analysis of samples outside of the 1F units.

Manufacturability and strength assessment of modified 9Cr-1Mo steel products for Japan sodium cooled fast reactor components, 2; Long thin-walled tubes with small diameter

Wakai, Takashi; Onizawa, Takashi; Obara, Satoshi; Nakashima, Takashi*; Yokoyama, Tetsuo*; Iseda, Atsuro*; Ogumo, Shinya*; Futagami, Satoshi*

Tainetsu Kinzoku Zairyo Dai-123-Iinkai Kenkyu Hokoku, 52(2), p.171 - 181, 2011/07

To enhance the economic competitiveness, high-Cr ferritic steels are adopted as the structural materials for JSFR, because the steels have both excellent high temperature strength and thermal properties. Among the high-Cr ferritic steels, modified 9Cr-1Mo steel (compatible to ASTM A213 T91) is a candidate of the structural material for the demonstration facility of JSFR, because the steel has superior microstructure stability at elevated temperature for long time. As for the steam generator tubes, to enhance the safety, straight double-walled tubes will be employed. In this study, the following technical issues were investigated; (1) Industrial manufacturability of thin-walled small bore tubes made of modified 9Cr-1Mo steel, (2) performance demonstration of the thin-walled small bore tubes, (3) industrial manufacturability of double-walled tubes using the thin-walled small bore tubes and (4) extraction of technical problems to manufacture the double-walled tubes for the JSFR steam generator. As a result, thin-walled small bore tubes made of modified 9Cr-1Mo steel were successfully manufactured by using the existing industrial facilities, up to 17m in length. The mechanical properties of the tubes satisfy the requirements from plant designing, as well as those from the material strength standards. Further, double walled tubes were also manufactured, up to 15m in length. The surface conditions of the tubes and the contact pressure between inner and outer tubes should be optimized.

Japanese evaluated nuclear data library version 3 revision-3; JENDL-3.3

Shibata, Keiichi; Kawano, Toshihiko*; Nakagawa, Tsuneo; Iwamoto, Osamu; Katakura, Junichi; Fukahori, Tokio; Chiba, Satoshi; Hasegawa, Akira; Murata, Toru*; Matsunobu, Hiroyuki*; et al.

Journal of Nuclear Science and Technology, 39(11), p.1125 - 1136, 2002/11

https://doi.org/10.3327/jnst.39.1125

Evaluation for JENDL-3.3 has been performed by considering the accumulated feedback information and various benchmark tests of the previous library JENDL-3.2. The major problems of the JENDL-3.2 data were solved by the new library: overestimation of criticality values for thermal fission reactors was improved by the modifications of fission cross sections and fission neutron spectra for U; incorrect energy distributions of secondary neutrons from important heavy nuclides were replaced with statistical model calculations; the inconsistency between elemental and isotopic evaluations was removed for medium-heavy nuclides. Moreover, covariance data were provided for 20 nuclides. The reliability of JENDL-3.3 was investigated by the benchmark analyses on reactor and shielding performances. The results of the analyses indicate that JENDL-3.3 predicts various reactor and shielding characteristics better than JENDL-3.2.

Detection of synchrotron radiation by Nb-based superconducting tunnel junctions

Maehata, Keisuke*; *; *; *; *; *; *; *; *; Katagiri, Masaki

Japanese Journal of Applied Physics, 35(2A), p.L178 - L181, 1996/00

https://doi.org/10.1143/JJAP.35.L178

no abstracts in English

Japanese evaluated nuclear data library, version-3; JENDL-3

Shibata, Keiichi; Nakagawa, Tsuneo; Asami, Tetsuo*; Fukahori, Tokio; ; Chiba, Satoshi; Mizumoto, Motoharu; ; ; Nakajima, Yutaka; et al.

JAERI 1319, 516 Pages, 1990/06

JAERI-1319.pdf:11.52MB

no abstracts in English

Proceedings of the 1983 Seminar on Nucloar Data

; ; Nakazawa, Masaharu*; *; *; ; ;

JAERI-M 84-010, 426 Pages, 1984/03

JAERI-M-84-010.pdf:11.04MB

no abstracts in English

Fundamental research on fission product chemistry under a severe accident

Miwa, Shuhei; Nakajima, Kunihisa; Di Lemma, F. G.; Suzuki, Chikashi; Yamashita, Shinichiro; Okane, Tetsuo; Takai, Toshihide; Takada, Juntaro; Furukawa, Tomohiro; Osaka, Masahiko

no journal, , 

JAEA conducts a fundamental research on fission product (FP) chemistry to construct the database of FP chemistry at each stage of nuclear power plants and improve FP chemistry models which will be reflected to the improvement of FP release and transport models. Main target of FP elements are Cs and I, and the evaluation of FP and B release kinetics, development of direct measurement technique of FP chemical form, the evaluation of Cs chemisorption behavior to SS, upgrading the thermodynamic database are carried out with focuses on Mo and BWR control material, boron carbide (BC).

Results and progress of fundamental research on FP chemistry

Osaka, Masahiko; Nakajima, Kunihisa; Miwa, Shuhei; Miyahara, Naoya; Suzuki, Eriko; Suzuki, Chikashi; Horiguchi, Naoki; Imoto, Jumpei; Liu, J.; Nishioka, Shunichiro; et al.

no journal, , 

Fundamental research on fission product (FP) chemistry is underway at Japan Atomic Energy Agency. The purpose is to establish a FP chemistry database in each region of a LWR under severe accident conditions. Improvement of FP chemical models based on this database is also an important task of the research. Research outputs are reflected to the research and development of decommissioning of Fukushima Daiichi Nuclear Power Station (1F) and the enhancement of LWR safety. Four research items have thus been established considering the specific issues of 1F and the priority in the source term research area, as follows: - Effects of boron (B) release kinetics and thermal-hydraulic conditions on FP behavior, - Cesium (Cs) chemisorption and reactions with structural materials, - Establishment of a thermodynamic and thermophysical properties database for FP compounds, - Development of experimental and analytical techniques for the reproduction of FP behavior. In this paper, results and progress of the research are presented.

Cs chemical reaction with stainless steel under a LWR severe accident, 2; Analysis of HAXPES measurements on Cs chemisorbed compounds adsorbed by a DFT calculation

Suzuki, Chikashi; Kobata, Masaaki; Nakajima, Kunihisa; Okane, Tetsuo; Osaka, Masahiko

no journal, , 

In order to evaluate the distribution and properties of Cs in reactors for the decommissioning of Fukushima Daiichi Nuclear Power Plant (1F), we study behaviors of Cs chemisorption to structural materials at high temperature. We are evaluating compounds formed by the chemisorption by hard X-ray photoemission spectroscopy (HAXPES). Cs-Si-O and Cs-Fe-Si-O compounds are formed by the Cs chemisorption, but these compounds are so hygroscopic that it is necessary to confirm validity of the measured HAXPES spectra. Therefore, we evaluated HAXPES of CsSiO, Cs SiO and CsFeSiO using first principles calculations. In the measurement results, the energy of CsSiO and CsSiO are almost the same, while that of CsFeSiO is lower. The calculated results showed the same tendency as the measured ones. This indicates that the HAXPES measurement results of CsSiO, CsSiO and CsFeSiO can be regarded as valid.