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Yoshii T, Sakai H, Kawarabayashi J. Influence of conversion factors on the radioactivity evaluation of clearance objects consisting of several materials. Appl Radiat Isot 2023; 200:110984. [PMID: 37597271 DOI: 10.1016/j.apradiso.2023.110984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/18/2023] [Accepted: 08/14/2023] [Indexed: 08/21/2023]
Abstract
Control panel waste generated from nuclear power plants is a new candidate for clearance under Japan's amended regulations. In the radioactivity evaluation, a simplified conversion factor for density and source location conditions has been used, assuming that it applies to unmixed materials such as metals. To investigate its applicability to control panels consisting of metal and organic materials, we examined the application of the conventional conversion factor by simulations of radiation measurements for a point source in a control panel.
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Affiliation(s)
- Taiki Yoshii
- Nuclear Regulation Authority (NRA), 1-9-9, Roppongi, Minato-ku, Tokyo, 106-8450, Japan; Tokyo City University, 1-28-1, Tamazutsumi, Setagaya-ku, Tokyo, 158-8557, Japan.
| | - Hirotaka Sakai
- Nuclear Regulation Authority (NRA), 1-9-9, Roppongi, Minato-ku, Tokyo, 106-8450, Japan
| | - Jun Kawarabayashi
- Tokyo City University, 1-28-1, Tamazutsumi, Setagaya-ku, Tokyo, 158-8557, Japan
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Xue Y, Lv H, Gao J, Liang Y, Li T, Zheng Y, Wang G, Yan Y, Ma F. Decontamination of uranium-containing radioactive waste from stainless steel surfaces using NaOH-based molten salts. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:64771-64777. [PMID: 37099110 DOI: 10.1007/s11356-023-27210-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 04/20/2023] [Indexed: 05/11/2023]
Abstract
Herein, we report a new strategy for the rapid removal of uranium-containing contaminants from metal surfaces, and it relies on decontaminants made of NaOH-based molten salts. The addition of Na2CO3 and NaCl to NaOH exhibited superior decontamination performance, with a decontamination rate of 93.8% within 12 min, outdoing the performance of the single NaOH molten salt. The experimental results demonstrated that the synergistic effects between CO32- and Cl- promoted the corrosion efficiency of the molten salt on the substrate, which accelerated the decontamination rate. Additionally, benefiting from the optimization of the experimental conditions by the response surface method (RSM), the decontamination efficiency was improved to 94.9%. Notably, it also showed remarkable results in the decontamination of specimens containing different uranium oxides at low and high levels of radioactivity. This technology is promising for broadening the path in rapid decontamination of radioactive contaminants on metal surfaces.
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Affiliation(s)
- Yun Xue
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, People's Republic of China
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China
| | - Huitao Lv
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, People's Republic of China
| | - Jianzhang Gao
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, People's Republic of China
| | - Yi Liang
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China
| | - Tianyu Li
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, People's Republic of China
| | - Yanghai Zheng
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China
| | - Guixiang Wang
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China
| | - Yongde Yan
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China
| | - Fuqiu Ma
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin, 150001, People's Republic of China.
- Yantai Research Institute, Harbin Engineering University, Yantai, 264006, Shandong, People's Republic of China.
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Ohashi Y, Shimaike M, Matsumoto T, Takahashi N, Yokoyama K, Morimoto Y. Current Status of Decommissioning and Waste Management at the Ningyo-Toge Environmental Engineering Center. NUCL TECHNOL 2023. [DOI: 10.1080/00295450.2022.2145136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Yusuke Ohashi
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Masamitsu Shimaike
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Takashi Matsumoto
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Nobuo Takahashi
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Kaoru Yokoyama
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Yasuyuki Morimoto
- Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
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Yoshii T, Sakai H, Tagawa H, Kawarabayashi J. Study on the effects of heterogeneity of objects placed in storage containers on simple radioactivity evaluation. ANN NUCL ENERGY 2022. [DOI: 10.1016/j.anucene.2022.109313] [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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Yokoyama K, Ohashi Y. Clearance measurement for concrete waste generated by the decommissioning of uranium processing facilities. ANN NUCL ENERGY 2022. [DOI: 10.1016/j.anucene.2022.109240] [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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