Development of fission product chemistry database ECUME for the LWR severe accident

Miwa, Shuhei; Nakajima, Kunihisa; Miyahara, Naoya; Nishioka, Shunichiro; Suzuki, Eriko; Horiguchi, Naoki; Liu, J.; Miradji, F.; Imoto, Jumpei; Afiqa, B. M.; et al.

Mechanical Engineering Journal (Internet), 7(3), p.19-00537_1 - 19-00537_11, 2020/06

https://doi.org/10.1299/mej.19-00537

We constructed the fission product (FP) chemistry database named ECUME for LWR severe accident. This version of ECUME is equipped with dataset of the chemical reactions and their kinetics constants for the reactions of cesium(Cs)-iodine(I)-boron(B)-molybdenum(Mo)-oxygen(O)-hydrogen(H) system in gas phase, the elemental model for the high temperature chemical reaction of Cs with stainless steel applied as the structural material in a reactor, and thermodynamic data for CsBO vapor species and solids of CsSiO and CsFeSiO for these chemical reactions. The ECUME will provide estimation of Cs distribution due to the evaluation of effects of interaction with BWR control material B and stainless steel on Cs behavior in the Fukushima Daiichi Nuclear Power Station.

Advances in fuel chemistry during a severe accident; Update after Fukushima Daiichi Nuclear Power Station (FDNPS) accident

Kurata, Masaki; Osaka, Masahiko; Jacquemain, D.*; Barrachin, M.*; Haste, T.*

Advances in Nuclear Fuel Chemistry, p.555 - 625, 2020/00

https://doi.org/10.1016/B978-0-08-102571-0.00015-X

The importance of fuel chemistry has been revivaled since Fukushima-Daiichi Nuclear Power Station (FDNPS) accident. The inspection and analysis of damaged three units, which had been operated in March 11, 2011, showed large differences in the accident progression sequence for these units, because operators attempted to prevent or mitigate the accident progression of each unit by all means possible. Characteristics of fuel debris are considered to be largely influenced by the difference in the sequence and, hence, deviated from those predicted from prototypic accident scenarios, which had been mainly identified from the analysis of Three Mile Island-2 (TMI-2) accident and the following sim-tests. For the proper improvement of our knowledge on severe accident (SA), including non-prototypic conditions, one has to start improving the phenomenology of fuel/core degradation and fission product (FP) behavior. Advances in the chemistry is the most essential approach. The present review attempts to focus on the recent updates and remaining concerns after the FDNPS accident.

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.

Radioactive Nuclides in Nuclear Reactors

JAERI-M 82-169, 137 Pages, 1982/12

JAERI-M-82-169.pdf:3.57MB

no abstracts in English

Fundamental study on fission product chemistry under LWR severe accident condition

Osaka, Masahiko

no journal, , 

Fundamental study on fission product chemistry under LWR severe accident condition has been conducted for the purpose of contributing to debris removal work towards the decommissioning of Fukushima Daiichi Nuclear Power Station. Recent results of the study are introduced in this conference.

Fundamental research on FP chemistry; Boron effects on cesium and iodine chemistry

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

no journal, , 

We have been conducting the fundamental study on fission product (FP) chemistry under severe accident (SA) conditions. The objective is to construct the FP chemistry database and to improve FP chemistry model for the improvement of source term evaluation technology. We have established the technical basis, such as experimental set-up and analysis tool, for the evaluation of FP chemistry in SA conditions. Fundamental knowledges on the effects of boron on the cesium and iodine chemistry were also obtained.