Chemical reactions of fission product deposits and iodine transport in primary circuit conditions
Autor: | Riitta Zilliacus, Unto Tapper, Ari Auvinen, Jorma Jokiniemi, Teemu Kärkelä, Jarmo Kalilainen |
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Rok vydání: | 2014 |
Předmět: |
inorganic chemicals
Nuclear and High Energy Physics Nuclear fission product Hydrogen Mechanical Engineering Radiochemistry chemistry.chemical_element Molybdate Iodine complex mixtures Chemical reaction chemistry.chemical_compound Nuclear Energy and Engineering chemistry Molybdenum Caesium General Materials Science Safety Risk Reliability and Quality Boron Waste Management and Disposal |
Zdroj: | Kalilainen, J, Kärkelä, T, Zilliacus, R, Tapper, U, Auvinen, A & Jokiniemi, J 2014, ' Chemical reactions of fission product deposits and iodine transport in primary circuit conditions ', Nuclear Engineering and Design, vol. 267, pp. 140-147 . https://doi.org/10.1016/j.nucengdes.2013.11.078 |
ISSN: | 0029-5493 |
Popis: | The objective of this work was to examine the chemical reactions taking place on primary circuit surfaces and their effect on fission product transport in a severe nuclear reactor accident. Especially transport of gaseous and aerosol phase iodine was studied. Caesium iodide (CsI) was used as precursor material for iodine species. Also, effects of molybdenum and boron on transport of iodine were investigated. The experimental work showed that when CsI alone was used as a precursor, as much as 20% of the released iodine was in gaseous form and the rest as aerosol particles. Aerosol particles were most likely CsI. When the amount of hydrogen in the carrier gas was increased, the fraction of gaseous iodine decreased. When Boron was added to the precursor, a glassy caesium borate surface was formed on the crucible. Boron trapped most of the caesium and also a fraction of iodine, causing almost all released iodine to be in gaseous form. When Mo was introduced in the precursor, most of the iodine was again released in gaseous form. Oxidised Mo reacted with caesium releasing iodine from CsI. The effect of Mo on iodine transport depended much on H2 concentration and was observed to be substantially greater on stainless steel surface. When stainless steel crucible was used, Mo was found in small amounts from aerosol particles, indicating that it was probably released as caesium molybdate or as molybdenum oxide. |
Databáze: | OpenAIRE |
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