Used nuclear fuel storage options including implications of small modular reactors

Abstract

This work addresses two aspects of the nuclear fuel cycle system with significant policy implications. The first is the preferred option for used fuel storage based on economics: local, regional or national storage. The second is the implications of small modular reactor (SMR) introduction for the nuclear fuel cycle, including demand for uranium, enrichment services and the amount of used nuclear fuel. The study considers the nuclear energy system evolution over a period of 100 years. Through a review of available literature, post-reactor fuel storage and handling options have been evaluated using the best economic parameters that can be found. A system dynamics module, known as the Used Nuclear Fuel Module (UNFM), was created to account for the costs of on-site or off-site storage, and the needed transportation to the storage location. It provides an easy to use interface for studies of economics of used fuel storage. This module was used to evaluate the local, regional, and national storage options of used nuclear fuel. The results indicate that local storage on reactor sites is the least cost option, and that the cost of the storage casks is the most sensitive parameter for the local option cost. Additionally, a module was created for the study of the impact of small modular reactors, known as the SMRM or Small Modular Reactor Module, to study the fuel cycle impacts. This module was then incorporated into the library of reactor types in CAFCA to enable its inclusion in nuclear fuel cycle studies. The assumption was made that about 80% of the new capacity of nuclear power plants would be of the SMR type for a high deployment and 20% of the new capacity of SMR type for a low deployment with the nuclear power growth rate is 2.5% for the period from 2014 to 2114. It is shown that the single-batch nuclear fuel cycle approach of SMRs will require higher enrichment, more uranium ore and enrichment services will be needed. Also, given the lower burnup of the discharged fuel, larger amount of stored fuel will materialize. Given that the SMRs are likely to be built on new sites, there will also be significantly more sites containing the used nuclear fuel.