Radioactive noble gases in surface air monitored at MRI, Tsukuba, before and after the JCO accident

Monitoring results of radioactive noble gases after the JCO criticality acc ident, Tokai, Japan at the MRI, Tsukuba, about 60 km southwest of the accid ent site, are presented. Although the experiments to detect radioactive nob le gases from the JCO accident proved negative, the the possible transport of a radioactive plume from the accident site is described based on the win d data obtained at two meteorological observation towers in Tokai and Tsuku ba. Also, the maximum emissions of the noble gases from the accident are ev aluated on the basis of the observations. (C) 2000 Elsevier Science Ltd. Al l rights reserved.