Iwai Satoshi, Sasaki Michiya, Higaki Shogo, Yamanishi Hirokuni, Kai Michiaki
Japan Nuclear Safety Institute: 5-36-7 Shiba, Minato-ku, Tokyo 108-0014, Japan.
J Radiol Prot. 2019 Jun 4;39(4):1092-1104. doi: 10.1088/1361-6498/ab26e1.
This paper describes an overview of the radiation protection response to the Plutonium intake accident that occurred at the Plutonium Fuel Facility of the Oarai Research and Development Center of the Japan Atomic Energy Agency on 6 June 2017. In the hood of the analyzing room at the Plutonium Fuel Facility five workers were checking a storage container of fast reactor nuclear fuel material. Around 11:15 a.m., vinyl bags inside the fuel material container containing Plutonium and enriched uranium burst during the inspection work. All the workers heard the bang, which caused misty dust leakage from the container. This event caused significant both skin and nasal α-contamination for three workers and just skin α-contamination for one worker. Decontamination was conducted in the shower room. Then the five workers were transferred to the Nuclear Fuel Cycle Engineering Laboratory to evaluate inhalation intake of Plutonium etc in the lungs. The maximum values of 2.2 × 10 Bq for Pu and 2.2 × 10 Bq for Am were estimated by the lung monitor. Based on these results, injection of a chelate agent was conducted for prompt excretion of Plutonium etc. The next morning, the five workers were transferred to the National Institute of Radiological Sciences for treatment including decontamination of their skin and measurement by a lung monitor. At that time no obvious energy peak was confirmed for Plutonium. The Japan Health Physics Society launched an ad-hoc working group for Plutonium intake accident around the middle of June to survey issues and to extract lessons for radiological protection. The authors, who are the members of the ad-hoc working group, here report the activity of the working group.
本文概述了对2017年6月6日发生在日本原子能机构大洗研发中心钚燃料设施的钚摄入事故的辐射防护应对措施。在钚燃料设施分析室的通风橱内，五名工作人员正在检查快堆核燃料材料的储存容器。上午11点15分左右，装有钚和浓缩铀的燃料材料容器内的塑料袋在检查工作期间破裂。所有工作人员都听到了爆炸声，这导致容器有薄雾状粉尘泄漏。该事件导致三名工作人员皮肤和鼻腔受到严重α污染，一名工作人员仅皮肤受到α污染。在淋浴室进行了去污处理。然后，这五名工作人员被转移到核燃料循环工程实验室，以评估肺部钚等物质的吸入摄入量。肺部监测仪估计钚的最大值为2.2×10贝克勒尔，镅的最大值为2.2×10贝克勒尔。基于这些结果，注射了螯合剂以促进钚等物质的排泄。第二天早上，这五名工作人员被转移到国立放射科学研究所进行治疗，包括皮肤去污和肺部监测仪测量。当时未确认钚有明显的能量峰。日本健康物理学会在6月中旬左右成立了一个钚摄入事故特别工作组，以调查相关问题并吸取辐射防护方面的经验教训。作为特别工作组成员的作者在此报告工作组的活动情况。
