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Liang H, Erkan N, Wang K, Sharma AK, Suzuki S. Numerical simulation of aerosol generation by cutting fuel debris and aerosol removal by spray droplets during Fukushima decommissioning. PROGRESS IN NUCLEAR ENERGY 2023. [DOI: 10.1016/j.pnucene.2023.104667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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Morishita Y, Takasaki K, Kitayama Y, Tagawa A, Shibata T, Hoshi K, Kaneko J, Higuchi M, Oura M. A phoswich alpha/beta detector for monitoring in the site of Fukushima Daiichi Nuclear Power Station. RADIAT MEAS 2022. [DOI: 10.1016/j.radmeas.2022.106896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Makarov A, Momotov V, Lakeev P, Sivkova V, Nezgovorov N, Semin S, Istomin I, Solopenko M, Anufrieva A, Nesterov V, Stepanov S, Pashkovsky R, Bendasov D. Experimental cutting of SNF samples by mechanical and thermal methods to examine the efficiency of different air filtration techniques of generated dust. ANN NUCL ENERGY 2022. [DOI: 10.1016/j.anucene.2022.109103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Porcheron E, Leblois Y, Gelain T, Chagnot C, Journeau C, Roulet D. Assessment of Spray and Pool Scrubbing Efficiencies for Means of Mitigation Against Aerosol Dispersion in the Context of Fuel Debris Retrieval at Fukushima Daiichi: Part II. JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2022. [DOI: 10.1115/1.4051538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
The general context of this paper is an evaluation of strategies that can be used to mitigate aerosol dispersion during fuel debris or corium retrieval in damaged Fukushima Daiichi reactors. Knowledge of the aerosol source terms released during fuel debris retrieval operations is one of the key factors for assessing aerosol dispersion leading to the potential dissemination of radionuclides into the environment. Our approach is to couple experimental results from integral tests obtained during laser cutting experiments, well-controlled analytical tests with separated effects performed in a dedicated facility to reproduce two-phase flow such as flows representative of pool scrubbing and spray scrubbing conditions, and numerical simulations. Integral tests provide relevant information on the airborne particle release fraction during laser cutting for underwater conditions at different water depths, such as the particle concentration and particle size distribution. However, the detailed characterization of two-phase flows, such as the size and velocity of gas bubble and water droplets generated by spray systems, is not possible during laser cutting integral tests. Therefore, a more analytical approach is necessary to obtain detailed information on two-phase flow, composed of bubbles in water, inducing pool scrubbing phenomenon, and droplets in gas generated by spray scrubbing systems used for mitigating dust dispersion, which are essential to the physical mechanisms of both processes and enable their respective efficiencies to be evaluated. The main objectives of this work were to develop models and ensure their validation based on experimental approach for predicting the pool scrubbing and spray scrubbing efficiencies in the context of fuel debris removal at Fukushima Daiichi.
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Affiliation(s)
- Emmanuel Porcheron
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA , Gif-sur-Yvette 91192, France
| | - Yohan Leblois
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA , Gif-sur-Yvette 91192, France
| | - Thomas Gelain
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA , Gif-sur-Yvette 91192, France
| | - Christophe Chagnot
- French Alternative Energies and Atomic Energy Commission (CEA), DEN , Paris Saclay, DM2S/SEMT/LTA, Gif-sur-Yvette 91192, France
| | - Christophe Journeau
- French Alternative Energies and Atomic Energy Commission , DES, IRESNE, DTN, SMTA, LEAG, Cadarache, Saint-Paul-lez-Durance 13108, France
| | - Damien Roulet
- ONET Technologies , 36 Bd des océans, Marseille 13258, France
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Abstract
In conjunction with the increasing demand for material cutting, such as the decommissioning and dismantling of nuclear facilities, advanced cutting technologies need be developed to increase precision and cost-effectiveness. As compared with other cutting technologies, laser cutting offers advantages of greater cutting precision, accuracy, and customization. In this work, we investigated the constitution, classification, and current status of this technology. Pollutant emission during laser cutting, corresponding pollution control methods and apparatus were proposed as well. Laser cutting equipment mainly comprises an automated system integrating a fiber laser, industrial computer, servo motor control, electrical control, and detection technology. It mainly consists of mechanical and electrical control parts. Laser cutting equipment is distinguished by light source, power, and cutting dimensions. Known variants of laser cutting technology involve vaporization, fusion, reactive fusion, and controlled fracture cutting. During the cutting process, dust, smoke, and aerosols can be released, which is an environmental concern and poses a threat to public health. The selection of the dedusting method and design of apparatus should take into account the dust removal rate, initial capital cost, maintenance cost, etc. Multi-stage filtration such as bag filtration combined with activated carbon filtration or electrostatic filtration is accepted.
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Kurata M, Okuzumi N, Nakayoshi A, Ikeuchi H, Koyama S. Step-by-step challenge of debris characterization for the decommissioning of Fukushima-Daiichi Nuclear Power Station (FDNPS). J NUCL SCI TECHNOL 2022. [DOI: 10.1080/00223131.2022.2040393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Masaki Kurata
- Japan Atomic Energy Agency (JAEA), Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Motooka-Otsuka, Tomioka-machi, Fukushima-ken, Japan
- International Research Institute for Nuclear Decommissioning (Irid), Nishi-Shinbashi, Minato-ku, Tokyo, Japan
| | - Naoaki Okuzumi
- International Research Institute for Nuclear Decommissioning (Irid), Nishi-Shinbashi, Minato-ku, Tokyo, Japan
| | - Akira Nakayoshi
- Japan Atomic Energy Agency (JAEA), Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Motooka-Otsuka, Tomioka-machi, Fukushima-ken, Japan
- International Research Institute for Nuclear Decommissioning (Irid), Nishi-Shinbashi, Minato-ku, Tokyo, Japan
| | - Hirotomo Ikeuchi
- Japan Atomic Energy Agency (JAEA), Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Motooka-Otsuka, Tomioka-machi, Fukushima-ken, Japan
- International Research Institute for Nuclear Decommissioning (Irid), Nishi-Shinbashi, Minato-ku, Tokyo, Japan
| | - Shinichi Koyama
- Japan Atomic Energy Agency (JAEA), Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Motooka-Otsuka, Tomioka-machi, Fukushima-ken, Japan
- International Research Institute for Nuclear Decommissioning (Irid), Nishi-Shinbashi, Minato-ku, Tokyo, Japan
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Porcheron E, LEBLOIS Y, Gélain T, CHAGNOT C, Journeau C, ROULET D. Assessment of Spray and Pool Scrubbing Efficiencies for Means of Mitigation Against Aerosol Dispersion in the Context of Fuel Debris Retrieval at Fukushima Daiichi: Part I. JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2021. [DOI: 10.1115/1.4051611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
The general context of this paper is an evaluation of strategies that can be used to mitigate aerosol dispersion during fuel debris or corium retrieval in damaged Fukushima Daiichi reactors. Knowledge of the aerosol source terms released during fuel debris retrieval operations is one of the key factors for assessing aerosol dispersion leading to the potential dissemination of radionuclides into the environment. Our approach is to couple experimental results from integral tests obtained during laser cutting experiments, analytical tests performed in a dedicated facility to reproduce two-phase flow such as flows representative of pool scrubbing and spray scrubbing conditions, and numerical simulations. Integral tests provide relevant information on the airborne particle release fraction during laser cutting for underwater conditions at different water depths, such as the particle concentration and particle size distribution. However, the detailed characterization of two-phase flows, such as the size and velocity of gas bubble and water droplets, is not possible during laser cutting integral tests. Therefore, a more analytical approach is necessary to obtain detailed information on two-phase flow, composed of bubbles in water, inducing pool scrubbing phenomenon, and droplets in gas generated by spray scrubbing systems, which are essential to the physical mechanisms of both processes and enable their respective efficiencies to be evaluated. The main objectives of this work were to develop models and ensure their validation based on experimental approach for predicting the pool scrubbing and spray scrubbing efficiencies in the context of fuel debris removal at Fukushima Daiichi.
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Affiliation(s)
- Emmanuel Porcheron
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, Gif-sur-Yvette, 91192, France
| | - Yohan LEBLOIS
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, Gif-sur-Yvette, 91192, France
| | - Thomas Gélain
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, Gif-sur-Yvette, 91192, France
| | - Christophe CHAGNOT
- Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, Paris Saclay, DM2S/SEMT/LTA, Gif-sur-Yvette, 91192, France
| | - Christophe Journeau
- Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DES, IRESNE, DTN, SMTA, LEAG, Cadarache, Saint-Paul-lez-Durance, 13108, France
| | - Damien ROULET
- ONET Technologies, 36 Bd des océans, 13258, Marseille, France
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