Radiochemical analysis of rubble collected from Fukushima Daiichi Nuclear Power Station

A large amount of contaminated nibbles were generated by the accident at the Fukushima Daiichi Nuclear Power Station (F1NPS). For safe decommissioning of F1NPS, it is important to evaluate the composition and concentration of radionuclides in the rubbles. In this paper, to characterize the rubbles collected at F1NPS, radiochemical analysis was operated. As a result of radiochemical analysis, gamma-ray-emitting nuclides ⁶⁰Co, ¹³⁷Cs and ¹⁵⁴Eu, beta-ray-emitting nuclides ³H, ¹⁴C, ⁹⁰Sr and ⁹⁹Tc, and alpha-particle-emitting nuclides ^{238, 239+240}Pu, ²⁴¹Am and ²⁴⁴Cm were detected. In contrast, ⁹⁴Nb and ¹⁵²Eu concentrations were below the detection limit. Measured radioactive concentrations implied that ⁶⁰Co and ⁹⁰Sr concentrations depended on ¹³⁷Cs concentration respectively. This analysis was characterized the radioactivity concentrations of the rubbles. (author)