2000 Fiscal Year Final Research Report Summary
Development of Simultaneous Removal System for Radioactively Gaseous and Particulate Matters generated by Dismantlement of Nuclear Power Plants
Project/Area Number |
11450289
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Research Category |
Grant-in-Aid for Scientific Research (B).
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
化学工学一般
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Research Institution | Kanazawa University |
Principal Investigator |
EMI Hitoshi Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (90025966)
|
Co-Investigator(Kenkyū-buntansha) |
SHIRAO Shuichi Hitachi, Ltd., Back-End Engineering Center, Senior Researcher, バックエンド設計センター, 主任技師(研究職)
NAMIKI Norikazu Kanazawa University, Faculty of Engineering, Professor, 工学部, 助手 (40262555)
OTANI Yoshio Kanazawa University, Faculty of Engineering, Professor, 工学部, 教授 (10152175)
|
Project Period (FY) |
1999 – 2000
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Keywords | Cobalt Calbonyl / Decomposition / Particle Formation / Simultaneous Removal / Radioactive Matter / Dismantlement / Thermal Cutting |
Research Abstract |
The present work is aimed at developing a simultaneous removal system for gaseous and particulate matters generated by thermal cutting of activated steel constructions during the dismantlement of aged nuclear power plants. In the present work, we focused on octacarbonyl di-cobalt(OCDC), which belongs to cobalt-compounds with high radioactivity during the thermal cutting of steel constructions, and investigated its behaviors in gas phase. OCDC vapor was generated by atomization of OCDC-solution prepared with hexane followed by filtration of the formed mists. Then, we measured its decomposition rates at various residence times, its vapor concentrations and temperatures based on the assumption that this reaction is consecutive first-order reactions via an intermediate. As a result, it was found that the former process of decomposition into the intermediate dominates these reactions. Also, we estimated the size of generated particles, considering the decomposition tube to adjust the residence time for reaction as a diffusion tube, and obtained that the size was estimated to be at least larger than 1 nm. These findings suggested that we need the residence time of formed OCDC vapor more than 20s and the surrounding temperature somewhat higher than room one in order to convert it into particles and subsequently remove them with HEPA filters.
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Research Products
(2 results)