Survey and proposal for Japanese-English bilingual translation of technical terms focusing on nuclear disaster prevention

Togawa, Orihiko; Okuno, Hiroshi

JAEA-Review 2023-043, 94 Pages, 2024/03

JAEA-Review-2023-043.pdf:1.53MB

In order to translate nuclear disaster prevention documents written in Japanese into English, the Basic Act on Disaster Management, the Act on Special Measures Concerning Nuclear Emergency Preparedness, and the Convention on Nuclear Safety were surveyed for corresponding terms in Japanese and English. The survey results were integrated and unified English translations were selected. As a result, a Japanese-English correspondence table of technical terms in the field of nuclear disaster prevention was prepared and proposed.

The Nuclear criticality accident in Japan, Revisited

Okuno, Hiroshi; Suyama, Kenya

Proceedings of 12th International Conference on Nuclear Criticality Safety (ICNC2023) (Internet), 8 Pages, 2023/10

The criticality accident that resulted in the evacuation of residents occurred on September 30, 1999, at JCO's nuclear fuel fabrication plant in Ibaraki prefecture, Japan. This paper presents the outline, technical issues and background of the accident and the situations that followed. The review of this accident was one of the hot issues in the last ICNC2003 organized in Tokai-mura. At the this turn of ICNC in Japan, we would like to revisit the accident to reaffirm and share the idea that the response and preparedness should be strengthened to protect people and the environment from nuclear disasters. The accident occurred in a factory of JCO during the informal and unusual process of preparing a uranium nitrate solution of medium-enriched (18.8 weight% U) uranium from UO using the precipitation tank of 45 cm in diameter, which exceeded the critical diameter (ca. 23 cm) of an infinite cylinder with a full thick water reflector. A 2.2-cm-thick water "jacket" surrounded and enclosed the tank, and the jacket was connected to the cooling tower beside the factory. The jacket not only functioned as the neutron reflector but also prevented the evaporation of the solution, and then the criticality continued for about 20 hours. Because JCO's plant had not anticipated the criticality accident, the response to the accident was confusing. During the accident, the JAERI and JNC, both the predecessors of the Japan Atomic Energy Agency (JAEA), acted to terminate the criticality and reduce the residents' exposure to radiation. After the accident, the JAERI and the National Institute of Radiological Sciences provided the telephone consultation at the village office of Tokai-mura. The JNC did the same things at the prefectural building of Ibaraki to advise the residents. The presentation may include issues of applying the Slide rule, identifying a nuclear criticality accident to occur, and responding to the emergency.

Early emergency responses of the Japan Atomic Energy Agency against the Fukushima Daiichi Nuclear Power Station Accident in 2011

Okuno, Hiroshi; Sato, Sohei; Kawakami, Takeshi; Yamamoto, Kazuya; Tanaka, Tadao

Journal of Radiation Protection and Research, 46(2), p.66 - 79, 2021/06

https://doi.org/10.14407/jrpr.2020.00185

The nuclear accident at the Fukushima Daiichi Nuclear Power Station (NPS) of Tokyo Electric Power Company (TEPCO) was a typical one of the disastrous damages that induced evacuation of the residents around the NPS, which was triggered by the hugest earthquake and associated tsunami. This paper summarized early responses of the Japan Atomic Energy Agency (JAEA), especially of its Nuclear Emergency Assistance and Training Center (NEAT) to the off-site emergencies associated with the TEPCO's Fukushima Daiichi NPS. The paper addressed activities of emergency preparedness of the NEAT before 2011 in relevant to the TEPCO's Fukushima Daiichi NPS, the situation of the NEAT on March 11, 2011, and its early responses to the related off-site emergencies including those caused by the accident at the TEPCO's Fukushima Daiichi NPS. The paper also discussed issues associated with complex disasters.

Outline of Regional Workshops held in 2006 - 2017 by the International Atomic Energy Agency in the proposal of Nuclear Emergency Preparedness Group of the Asian Nuclear Safety Network

Okuno, Hiroshi; Yamamoto, Kazuya

JAEA-Review 2020-066, 32 Pages, 2021/02

JAEA-Review-2020-066.pdf:3.01MB

The International Atomic Energy Agency (abbreviated as IAEA) has been implementing the Asian Nuclear Safety Network (abbreviated as ANSN) activities since 2002. As part of this effort, Topical Group on Emergency Preparedness and Response (abbreviated as EPRTG) for nuclear or radiation disasters was established in 2006 under the umbrella of the ANSN. Based on the EPRTG proposal, the IAEA conducted 23 Asian regional workshops in the 12 years from 2006 to 2017. Typical topical fields of the regional workshops were nuclear emergency drills, emergency medical care, long-term response after nuclear/radiological emergency, international cooperation, national nuclear disaster prevention system. The Japan Atomic Energy Agency has produced coordinators for EPRTG since its establishment and has led its activities since then. This report summarizes the Asian regional workshops conducted by the IAEA based on the recommendations of the EPRTG.

Preparedness and response for nuclear or radiological emergency as a designated public corporation

Okuno, Hiroshi; Okamoto, Akiko; Ebine, Noriya; Hayakawa, Tsuyoshi; Tanaka, Tadao

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 15 Pages, 2019/05

In the event of a nuclear or radiological emergency, the Japan Atomic Energy Agency (JAEA) as a designated public corporation assigned in the Disaster Countermeasures Basic Act of Japan undertakes a role to support the national government and local governments. This paper (1) illuminates the roles of the JAEA as a designated public corporation for preparedness and response to a nuclear or radiological emergency of nuclear facilities; (2) summarizes emergency response activities of the JAEA in accordance with its Disaster Management Operation Plan against the off-site radiological emergencies attributed to a loss of control of the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station that occurred in 2011; and (3) reports its activities in normal times especially participation in the drills organized by the national government and local governments in the light of the Basic Disaster Management Plan of Japan and Local Disaster Management Plans of prefectural governments, respectively.

Calculations of safe distance from the point of a severe accident during transportation of a package containing spent nuclear fuels

Watanabe, Fumitaka; Okuno, Hiroshi

Proceedings of 18th International Symposium on the Packaging and Transport of Radioactive Materials (PATRAM 2016) (DVD-ROM), 9 Pages, 2016/09

This paper shows our calculations on the effects of a radiological release by assuming a severe accident in nuclear material transportation. Following recalculations of safe distance from the point of a severe accident during transportation of a transportation cask TN12 typically used in France containing spent nuclear fuel, and calculations to replicate the "Regulatory Guide: Emergency Preparedness for Nuclear Facilities", a similar calculation was made for a spent fuel transportation cask NFT-14P that was typically utilized in Japan instead of TN12. The safe distance was calculated to be about 30 m. The above calculations were made with the HotSpot codes which adopted the Gauss plume model and had been developed by the USA. Some additional calculations were made with EyesAct, which was developed and used in Japan, adopting also the Gauss plume model, to compare calculation results.

Non-destructive examination of jacket sections for ITER central solenoid conductors

Takahashi, Yoshikazu; Suwa, Tomone; Nabara, Yoshihiro; Ozeki, Hidemasa; Hemmi, Tsutomu; Nunoya, Yoshihiko; Isono, Takaaki; Matsui, Kunihiro; Kawano, Katsumi; Oshikiri, Masayuki; et al.

IEEE Transactions on Applied Superconductivity, 25(3), p.4200904_1 - 4200904_4, 2015/06

https://doi.org/10.1109/TASC.2014.2364632

The Japan Atomic Energy Agency (JAEA) is responsible for procuring all amounts of Central Solenoid (CS) Conductors for ITER, including CS jacket sections. The conductor is cable-in-conduit conductor (CICC) with a central spiral. A total of 576 NbSn strands and 288 copper strands are cabled around the central spiral. The maximum operating current is 40 kA at magnetic field of 13 T. CS jacket section is circular in square type tube made of JK2LB, which is high manganese stainless steel with boron added. Unit length of jacket sections is 7 m and 6,300 sections will be manufactured and inspected. Outer/inner dimension and weight are 51.3/35.3 mm and around 90 kg, respectively. Eddy Current Test (ECT) and Phased Array Ultrasonic Test (PAUT) were developed for non-destructive examination. The defects on inner and outer surfaces can be detected by ECT. The defects inside jacket section can be detected by PAUT. These technology and the inspected results are reported in this paper.

Fabrication process qualification of TF Insert Coil using real ITER TF conductor

Ozeki, Hidemasa; Isono, Takaaki; Kawano, Katsumi; Saito, Toru; Kawasaki, Tsutomu; Nishino, Katsumi; Okuno, Kiyoshi; Kido, Shuichi*; Semba, Tomoyuki*; Suzuki, Yozo*; et al.

IEEE Transactions on Applied Superconductivity, 25(3), p.4200804_1 - 4200804_4, 2015/06

https://doi.org/10.1109/TASC.2014.2364393

Annual report of Nuclear Emergency Assistance and Training Center (April 1, 2013 - March 31, 2014)

Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.

JAEA-Review 2014-048, 69 Pages, 2015/02

JAEA-Review-2014-048.pdf:13.91MB

JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations

Investigation of strand bending in the He-inlet during reaction heat treatment for ITER TF Coils

Hemmi, Tsutomu; Matsui, Kunihiro; Kajitani, Hideki; Okuno, Kiyoshi; Koizumi, Norikiyo; Ishimi, Akihiro; Katsuyama, Kozo

IEEE Transactions on Applied Superconductivity, 24(3), p.4802704_1 - 4802704_4, 2014/06

https://doi.org/10.1109/TASC.2013.2297685

Japan Atomic Energy Agency (JAEA), as Japan Domestic Agency, has responsibility to procure nine ITER Toroidal Field (TF) coils. The TF coil winding consists of a NbSn Cable-In-Conduit conductor, a pair of joints and a He-inlet. The current capacity of 68 kA is required at the magnetic field of 7 T around the He-inlet region in the TF coil winding. During reaction heat-treatment, the compressive residual strain in NbSn cable is induced by the difference in the thermal expansion coefficients between the NbSn cable and stainless steel jacket. The strands bending in the NbSn cable of the He-inlet is anticipated since there is the compressive residual strain and a gap between the NbSn cable and the He-inlet to introduce SHE flow. If the strand is bent, the variation of mechanical behaviors, such as the elongation of He-inlet during the reaction heat-treatment and the thermally induced residual strain on the jacket around the He-inlet, are expected. To investigate the strands bending in the NbSn cable of the He-inlet, the following items are performed; (1) elongation measurement during reaction heat-treatment, (2) residual longitudinal strain measurement using strain gauges by sample cuttings, (3) nondestructive inspection on the cable and strands using high resolution X-ray CT, Detail of test results and investigation of the strands bending in the NbSn cable of the He-inlet are reported and discussed.