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Sano, Naruto; Yamashita, Naoki; Hoshino, Kazutoyo*; Tsukada, Manabu*; Sawauchi, Fumiya*; Otake, Yoshinori; Ichise, Kenichi; Tagami, Susumu
JAEA-Technology 2022-034, 47 Pages, 2023/03
JAEA-Technology-2022-034.pdf:2.81MB
The Waste Safety Testing Facility (WASTEF) was established in 1982 as an experimental facility for long-term storage of solidified high-level radioactive waste generated in the reprocessing of spent light water reactor fuel and the subsequent safety assessment of geological disposal. It is a historic facility that started operation in 1982. This facility consists of 5 concrete cells, 1 lead cell, 6 glove boxes, and 7 hoods, and is a large-scale facility that can use nuclear fuel materials including uranium and plutonium and radioactive isotopes including TRU. In this facility, research and development requested by the research department is carried out in the Hot Material Examination Section. In addition, patrol inspections, self-inspections, etc. are also carried out as maintenance management based on safety regulations. This report summarizes the overview of WASTEF facilities, the results of operation, maintenance and management work in FY2021, and the future outlook.
Otake, Yoshinori; Tambo, Masaki; Kabir, M.*; Inada, Arisa; Fukaya, Hiroyuki; Kida, Takashi
no journal, ,
In March 2011, a large amount of radioactive cesium (hereinafter referred to as Cs) was dispersed over a wide area as a result of Fukushima Daiichi Nuclear Power Station accident after the devastating earthquake that occurred in Japan. The incinerated ash containing Cs generated by environmental decontamination has become a problem due to lack of storage space. The purpose of this study is to reduce the volume of designated waste that needs to be preserved by removing Cs from incinerator ash using Electrokinetic (EK) method. Two electrodes are placed in the polluted materials (i.e. incinerator ash for this study) with electrolyte solution and a DC voltage is applied in between the electrodes. It can be understood that the Cs ions will move to the cathode side and thus it will be removed from the incinerator ash. At first, a preliminary experiment was conducted with commercially available ash polluted with stable Cs with the concentration ratio 50 mg/kg. We found that more than 80% of stable Cs was separated from the ash with the EK treatment. Then we performed the EK treatment with two types of radioactive contaminated ashes (i.e. fly ash and bottom ash). The radioactive concentration of Cs was about 3,000 Bq/kg to 5,000 Bq/kg for the ashes. We succeeded in the separation of Cs from the ashes. Further works will be carried out with various test conditions, such as, the type of electrolyte and the structure of the test apparatus etc.
Kitatsuji, Yoshihiro; Fukaya, Hiroyuki; Haraga, Tomoko; Oka, Toshitaka; Otake, Yoshinori; Tambo, Masaki; Inada, Arisa; Aono, Ryuji; Kinase, Akari; Ikarugi, Riko; et al.
no journal, ,
To proceed with the decommissioning of Fukushima Daiichi Nuclear Power Station Accident (1F), it is necessary to secure human resources for radionuclide analysis, which is a prerequisite for the safe treatment and disposal of treated water and waste containing radionuclides generated as a result of the decommissioning. The Nuclear Science Research Institute of JAEA, together with the Fukushima Research and Engineering Institute, has started a project to train analytical personnel who will be responsible for decommissioning in the future. In this presentation, we will introduce the training of analytical operators, managers, and engineers for young staff members and our efforts using the summer intern program.
Yanagisawa, Kayo; Ikarugi, Riko; Morii, Shiori; Oka, Toshitaka; Kitatsuji, Yoshihiro; Fukaya, Hiroyuki; Haraga, Tomoko; Otake, Yoshinori; Tambo, Masaki; Inada, Arisa; et al.
no journal, ,
no abstracts in English
Otake, Yoshinori; Kabir, M.*; Fukaya, Hiroyuki; Tambo, Masaki; Inada, Arisa
no journal, ,
The widespread distribution of radioactive cesium resulting from the Fukushima Daiichi Nuclear Power Station accident poses a serious challenge in decontamination and waste management. Recognizing the critical importance of addressing this issue, JAEA recently launched a project to develop human resources and improve or validate existing technologies related to elemental and radionuclide analysis. Among these challenges, the safe and efficient disposal of incineration ash generated by burning cesium-contaminated combustible waste has become particularly urgent. Ash with activity levels exceeding 8,000 Bq/kg is temporarily stored as controlled waste, and there is an immediate need to establish an effective treatment method. Conventional chemical and physical techniques for radioactive substance separation involve system complexity and high operational costs, underscoring the demand for simpler and more energy-efficient alternatives. In this study, we evaluated the applicability of an electrokinetic technique - the Flat Electrode Method-ElectroKinetic (FEM-EK) process- which has been proven effective in removing cesium from soil and separating radioactive cesium from incineration ash generated during decontamination. Cesium distribution in the samples was characterized using a germanium semiconductor detector, which provided insights into cesium migration behavior before and after treatment. This presentation reports the results of electrokinetic experiments performed with both simulated and actual incineration ash, together with evaluations of cesium migration within the samples after treatment.
Otake, Yoshinori; Miyai, Hiromitsu; Kanazawa, Sota; Baba, Yosuke*
no journal, ,
The Japan Atomic Energy Agency (JAEA) is currently conducting a project aimed at human resource development and the advancement and validation of existing technologies for elemental and radionuclide analyses. This study forms a part of this project and targets the development of technologies to reduce the volume of generated nuclear radioactive waste. To this end, incineration ash derived from combustible waste contaminated with radioactive Cs was analyzed, and test equipment for Cs separation was subsequently developed. Its effectiveness was evaluated with the aim of reducing the storage facilities required for ash management. This report outlines the fabrication of the test equipment, which features a monovalent cation permselective ion-exchange membrane, and summarizes the results obtained from processing actual samples.
Tambo, Masaki; Fukaya, Hiroyuki; Kobayashi, Fuyumi; Otake, Yoshinori; Inada, Arisa; Mizokami, Masato*; Mizokami, Shinya*; Nakamura, Satoshi; Kitagaki, Toru; Takano, Masahide
no journal, ,
no abstracts in English