Estimation About Amounts of Radioactive Wastes From Fukushima Daiichi Nuclear Power Station

In this research, the amounts of the radioactive wastes generated by the secondary wastewater treatment was focused on. In this paper, at first, cooling water circulating in the plant and the facilities which are removing radionuclides were modeled and how the radionuclides migrate with elapsed time was formulated. Then, the analytic value was fitted to the measured value to compute undetermined coefficients of the formula by setting a migration rate of these nuclides leaching from fuel debris as the parameter for this calculation. Secondly, based on the above calculated inventory, the concentration of those nuclides per vessel was estimated and classified, supposing that the current standard of waste classification for disposal in the normal decommissioning can be applied even for this accident. In this case, the stabilization processing of wastes inside the vessels was not taken into consideration, and these were presumed to be restored directly. By this fitting, the results show that the migration rates of Cs-137 and Cs-134 are 24.4 TBq / day and 10.5 TBq / day. And the classification results indicate that the concentrations of almost all vessels are classified as the equivalent of pit disposal or trench disposal group.