Moreover, HTGR can effectively solve the problem of radioactive waste due to the high thermal efficiency, high burn-up, and etc, by reducing volume of waste and footprint of repository, which is area needed to dispose waste package. Especially for High Level Waste (HLW), JAEA performed investigation on the package number of HLW and repository footprint. As a result, with representative disposal method, the number and footprint per electricity generation can be reduced by 60% for direct disposal and by 30% for disposal with reprocessing compared with the case of Light Water Reactor (LWR). Furthermore, the footprint can be reduced by improve the disposal method. For the disposal with reprocessing, with cooling time of 100 years, the footprint can be reduced by 80% compared with a representative case. With cooling time of 150 years and group partitioning technique, the footprint can be reduced by 90%. It is found that very compact waste disposal can be realized without nuclear transmutation.
Direct disposal of Spent HTGR Fuels
Temperature change of bentonite after disposal
- Reference
- Y. Fukaya, T. Nishihara, “Reduction on high level radioactive waste volume and geological repository footprint with high burn-up and high thermal efficiency of HTGR,” Nucl. Eng. Des., 307, pp.188-196, (2016).
- Y. Fukaya, M. Goto, H. Ohahsi, et al.,"Optimization of disposal method and scenario to reduce high level waste volume and repository footprint for HTGR," Ann. Nucl. Eng, 116, p.224-234, (2018).