[2E08-10] Nuclear Data Evaluation, Uncertainty Evaluation

[2E10] Evaluation of Uncertainty of Radioactivity Caused by Important Nuclide in Short Cooling Term for Clearance Verification in Decommissioning

*Tatsuki Amitani¹, Tsunenori Inakura¹, Naoki Yamano¹, Ken-ichi Tanaka², Chikako Ishizuka¹, Masato Watanabe³, Ryoji Mizuno⁴, Satoshi Chiba¹ (1. Tokyo Tech, 2. IAE, 3. Chubu Electric Power, 4. Chuden CTI)

Keywords:Decommissioning, Clearance, Neutron cross section, Covariance, Uncertainty, Total Monte Carlo

To optimize disposal of low-level radioactive waste generated copiously in decommissioning of nuclear facilities, required are 1) reliable assessment of radioactive level by calculation and measurement and 2) a good estimate of the uncertainty of those result for the classification of radioactive waste. In order to improve the reliability of the calculations, we developed an estimation method of uncertainty of radioactivity caused by that of nuclear data based on nuclear data evaluation system T6 and Total Monte Carlo method using ORIGEN2. In this study, we used that method and calculated radioactivity uncertainty of ¹³⁴Cs, which is a dominant nucleus of ΣD/C (D: radioactivity concentration, C: clearance level) in short cooling term, due to uncertainty of nuclear data of parent nuclide.