Technical, regulatory, and policy feasibility assessments of rod consolidation in spent nuclear fuel disposal

Abstract

Various approaches have been proposed to address the challenges associated with storage and disposal of spent nuclear fuel. Rod consolidation, which involves extracting only the fuel rods from fuel assemblies and combining them for storage with reduced spacing, gained attention until the 1990s for its benefits in storage efficiency. In this case study, experts from diverse backgrounds evaluate the technical and political feasibility of rod consolidation for enhancing disposal practices. This study conducts a technical and regulatory analysis of rod consolidation under disposal conditions and evaluates its feasibility from a disposal perspective. From a technical viewpoint of 2:1 and 1.5:1 rod consolidations, the rod consolidation methods demonstrate positive effects on nuclear criticality compared to the reference, non-rod consolidation case. For the advanced repository design with elevated temperature conditions of 150 °C or higher, the applicability of rod consolidation becomes more convincing, thereby achieving a reduction in the number of required disposal canisters. In addition, regulatory considerations primarily focus on the requirements for applying rod consolidation technology under the Korea Nuclear Act. Moreover, this research conducts environmental, economic, and acceptance analyses to ascertain the viability of rod consolidation. The findings provide compelling evidence supporting the feasibility of rod consolidation technology for disposal purposes, highlighting its technical, regulatory, economic, environmental, and societal acceptance advantages. However, challenges remain, particularly concerning its applicability to high-burnup nuclear fuel and unresolved regulatory and technical issues.