Residual neutron-induced radionuclides in a soil sample collected in the vicinity of the criticality accident site in Tokai-mura, Japan: A Progress Report

Residual neutron-induced radionuclides were measured in a soil sample collected in the vicinity of the location where a criticality accident occurred (in Tokai-mura, from 30 September to 1 October, 1999). Concentrations of 24Na, 140La, 122Sb, 59Fe, 124Sb, 46Sc, 65Zn, 134Cs and 60Co in the soil sample were determined by γ-ray spectrometry, and neutron activation analysis was carried out for selected target elements in the sample. Tentative estimates of the apparent thermal and epithermal neutron fluences which reached the sample were obtained through combined analyses of 59Fe/58Fe, 124Sb/123Sb, 46Sc/45Sc, 65Zn/64Zn, 134Cs/133Cs and 60Co/59Co.