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Journal Articles

Study on chemisorption model of cesium hydroxide onto stainless steel type 304

Nakajima, Kunihisa; Nishioka, Shunichiro; Suzuki, Eriko; Osaka, Masahiko

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 8 Pages, 2019/05

Cesium chemisorption models were developed for estimation of amount of cesium chemisorbed onto stainless steel type 304 (SS304) during light water reactor severe accident. However, existing chemisorption models cannot accurately reproduce experimental results. In this study, a modified cesium chemisorption model was constructed based on a penetration theory for gas-liquid mass transfer with chemical reaction and was able to adequately describe effects on concentration of cesium hydroxide in gaseous phase and silicon content in SS304. It was found that the modified model can more accurately reproduce the experimental data than the existing model.

Journal Articles

Experimental study on Cs chemisorption behaviour onto stainless steel at around 873 K

Suzuki, Eriko; Takase, Gaku; Nakajima, Kunihisa; Nishioka, Shunichiro; Hashimoto, Naoyuki*; Isobe, Shigehito*; Osaka, Masahiko

Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR 2019) (Internet), 4 Pages, 2019/05

In order to acquire the knowledge of the Cs chemisorption behaviour in the lower temperature region, the Cs chemisorbed compounds and the surface reaction rates were investigated by conducting the Cs chemisorption tests onto stainless steel at 873 and 973 K. As a result, The cesium ferrate compounds were revealed to be formed at this temperatures. It was seen that the dependences of surface reaction rate constant on this temperature were different from that at the higher temperature region. This behaviour leads to the conclusion that the Cs chemisorption model in the low temperature region should be newly constructed.

Journal Articles

Effect of atmosphere on the vaporization behavior of CsFeSiO$$_{4}$$

Suzuki, Eriko; Nakajima, Kunihisa; Osaka, Masahiko

Progress in Nuclear Science and Technology (Internet), 5, p.165 - 167, 2018/11

In severe accident condition, CsFeSiO$$_{4}$$ could be formed by Cesium (Cs) chemisorption onto reactor structural materials. For evaluation of re-vaporization behavior, effect of atmosphere on the vaporization behavior of CsFeSiO$$_{4}$$ at high temperature was investigated by thermal gravimetric-differential thermal analyzer (TG-DTA) experiments. As a result, it was found that vaporization of CsFeSiO$$_{4}$$ in reducing atmosphere (Ar-5%H$$_{2}$$) started at relatively low temperature, about 800$$^{circ}$$C, compared with in atmosphere containing H$$_{2}$$O (Ar-5%H$$_{2}$$-5%H$$_{2}$$O). It was inferred that a possible chemical reaction for the weight loss at around 800$$^{circ}$$C would occurred by the decomposition of CsFeSiO$$_{4}$$ into volatile Cs vapor species under H$$_{2}$$.

Journal Articles

Results and progress of fundamental research on FP chemistry

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

Proceedings of 8th European Review Meeting on Severe Accident Research (ERMSAR 2017) (Internet), 11 Pages, 2017/05

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.

Journal Articles

${it Real time}$ observation on oxygen chemisorption states on Si(001)-2$$times$$1 during supersonic oxygen molecular beam irradiation

Yoshigoe, Akitaka; Teraoka, Yuden

Applied Surface Science, 190(1-4), p.60 - 65, 2002/05

 Times Cited Count:10 Percentile:48.84

no abstracts in English

Journal Articles

Initial oxidation states on Si(001) surface induced by translational kinetic energy of O$$_{2}$$ at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiation

Yoshigoe, Akitaka; Teraoka, Yuden

Surface Science, 482-485(Part.1), p.189 - 195, 2001/06

no abstracts in English

Journal Articles

Design of beamline end-station at BL23SU in SPring-8 for surface reaction dynamics study

Teraoka, Yuden; Yoshigoe, Akitaka

Atomic Collision Research in Japan, No.25, p.97 - 98, 1999/00

no abstracts in English

JAEA Reports

None

Sugihara, Yoichiro*; Mukai, Katsuyuki*; Nunomiya, Ichiro*

PNC-TJ6357 97-001, 40 Pages, 1997/03

PNC-TJ6357-97-001.pdf:1.52MB

None

JAEA Reports

None

*; Nagasaki, Shinya*

PNC-TJ1602 96-003, 45 Pages, 1996/03

PNC-TJ1602-96-003.pdf:0.83MB

None

JAEA Reports

None

PNC-TJ1564 95-001, 171 Pages, 1995/03

PNC-TJ1564-95-001.pdf:5.35MB

None

JAEA Reports

None

PNC-TJ1281 95-009, 168 Pages, 1995/03

PNC-TJ1281-95-009.pdf:5.16MB

None

JAEA Reports

None

PNC-TJ1602 94-003, 53 Pages, 1994/03

PNC-TJ1602-94-003.pdf:0.94MB

None

Journal Articles

Water adsorption on lithium oxide pellets in helium sweep gas stream

; Konishi, Satoshi; ; Kurasawa, T.; ; Naruse, Yuji

J.Nucl.Mater., 122-123, P. 934, 1984/00

no abstracts in English

Journal Articles

Removal mechanism of tritium by variously pretreated silica gel

Nakashima, Mikio; Tachikawa, Enzo; Saeki, Masakatsu;

Journal of Inorganic and Nuclear Chemistry, 43(2), p.369 - 373, 1981/00

 Times Cited Count:8 Percentile:61.05

no abstracts in English

Journal Articles

JAEA Reports

Capture of Fission Iodine Released from UO$$_{2}$$・Graphite Mixture with Various Ceramic Materials

; Shiba, Koreyuki;

JAERI-M 5847, 13 Pages, 1974/09

JAERI-M-5847.pdf:0.6MB

no abstracts in English

Oral presentation

Chemical impacts of boron on the cesium release and transport behavior under severe accident conditions, 2; On the cesium chemisorption behavior onto the stainless steel surfaces

Yamashita, Shinichiro; Miwa, Shuhei; Osaka, Masahiko; Nagase, Fumihisa

no journal, , 

Research articles related to the cesium (Cs) chemisorption onto the stainless steel (SS) was reviewed and then the model of Cs chemisorption process was assumed. By using chemical equilibrium calculation method, the assumed model was validated and effect of boron on Cs chemisorption was also discussed. Because of the difference in surface condition of SS, two samples which were assumed to be SS used and unused in reactor were considered. As the results of chemical equilibrium calculation, it were deduced that Cs would not react with outer oxide layer of a used SS with duplex layer and that Cs react with silicon (Si) atom, leading to the formation of Cs$$_{2}$$Si$$_{4}$$O$$_{9}$$. Also, there was little influence of boron (B) including environment on the formation of Cs$$_{2}$$Si$$_{4}$$O$$_{9}$$. On the other hand, it was confirmed that Cs would react with Cr$$_{2}$$O$$_{3}$$ film layer of an unused SS and resultantly formed Cs-Cr-O phase. In addition, it found that the formation of Cs-Cr-O phase was highly possible to be suppressed under B including environment.

Oral presentation

Cesium chemisorption behavior onto structural material under severe accident conditions, 1; Leaching behavior of Cs from Cs-chemisorbed stainless steel

Yamashita, Shinichiro; Miwa, Shuhei; Osaka, Masahiko; Nagase, Fumihisa

no journal, , 

In order to elucidate chemisorption behavior of cesium onto the structural material during severe accident, leaching behavior of cesium from cesium-chemisorbed stainless steel into solutions of water or citric acid was evaluated. Results of leaching test indicated that leaching rate of Cs for citric acid was higher than that for water and that, in the case of high chemisorption rate, amount of elutions of both cesium and silicon increased.

38 (Records 1-20 displayed on this page)