[1H10-13] Radionuclide Inventory

[1H10] Impact on geological disposal due to prolonged cooling period of spent fuel before reprocessing and study of mitigation measures

(1)The impact on characteristics of vitrified waste and temperature of engineered barrier

*Toyonobu Nabemoto¹, Takao Ikeda², Yasuhiro Suyama³, Kazuyoshi Takenobu⁴, Masakazu Chijimatsu⁵, Susumu Sakashita⁶, Satoshi Hirooka⁷, Arata Kurihara⁸, Masayoshi Kuji⁹, Hideki Takayama¹⁰ (1. IHI, 2. JGC JAPAN CORPORATION, 3. KAJIMA, 4. ATK-ENG, 5. HAZAMA ANDO, 6. OYO, 7. JX NIPPON EXPLORATION AND DEVELOPMENT, 8. DIA CONSULTANTS, 9. MAEDA, 10. ENAA)

Keywords:Geological disposal, Evaluation of engineered barrier temperature, Vitrified waste, Cooling period before reprocessing, Buffer material

To study the impact on geological disposal and its mitigation due to extending of precooling period prior to reprocessing of spent fuel, its vitrified waste inventory and temperature of engineered barrier are evaluated based on the NUMO pre-siting SDM-Based Safety Case. As a result, increase in peak temperature of buffer material, delay of appearance of the peak temperature, and slowdown in its temperature fall are identified and then mitigation for the impact on disposal system are reviewed.