Scientific approach of environmental impact of the criticality accident

由约60名成员组成的“环境放射性研究小组”和“人类效应研究小组”调查了JCO临界事故的环境影响。400多个环境样品(土壤、植物叶子、化学试剂、金属、硬币、食盐、糖、不锈钢、荧光灯、黄金制品等)都是在JCO校园内和周围收集的。测量了中子引起的放射性核素和裂变产物的浓度，作为离现场距离的函数。大多数结果发表在《环境放射性杂志》2000年第50卷上，作为东海村事故的特刊。对长寿命核素的测量仍在一些实验室继续进行。2000年6月举行的“第二届环境放射性与辐射暑期班”的讨论结果被公布为“核科学家在核事故情况下应该做些什么”。每个样本的实测值将作为“东海村事故数据库”开放，详细说明抽样图和调查人员等信息。两个研究小组的结果已在多个国内外研讨会上公布。

Environmental impact of the JCO criticality accident was investigated by "Environmental radioactivity research group" and "human effect research group" composed of about 60 members. More than 400 environmental samples (soil, plant leave, chemical reagent, metal, coin, table salt, sugar, stainless steel, fluorescent lamp, gold items etc.) were collected in and around the JCO campus. Concentrations of neutron-induced radionuclides and fission products were measured as a function of distance from the site. Most of the results were reported in "Journal of Environmental Radioactivity, Vol. 50, 2000" as the special issue on Tokai-mura accident. Measurements of long- lived nuclides are still continued in some laboratories. Result of discussion in "The 2_<nd> summer school on environmental radioactivity and radiation" held in June, 2000, was published as "What should be done by nuclear scientists in the case of nuclear accident". Measured values of each sample will be opened as "data base of Tokai- mura accident" with details on sampling map and investigator etc. Results of two research goups have been presented in number of domestic and international symposium.