Searching for the viability of using thorium-based accident-tolerant fuel for VVER-1200

Abstract

This study explores the feasibility of employing (U, Th)-based accident tolerant fuels (ATFs), specifically (0.8UO2, 0.2ThO2), (0.8UN, 0.2ThN), and (0.8UC, 0.2ThC). The investigation assesses the overall performance of these proposed fuel materials in comparison to the conventional UO2, focusing on deep neutronic and thermal-hydraulic (Th) analyses. Neutronic analysis utilized the MCNPX code, while COMSOL Multiphysics was employed for thermal-hydraulic analysis. The primary objective of this research is to overcome the limitations associated with traditional UO2 fuel by exploring alternative fuel materials that offer advantages in terms of abundance and potential improvements in performance and safety. Given the limited abundance of UO2, long-term sustainable nuclear energy production faces challenges. From a neutronic standpoint, the U–Th based fuels demonstrated remarkable fuel cycle lengths, except (0.8UN, 0.2ThN), which exhibited the minimum fuel cycle length and, consequently, the lowest fuel burn-up. Regarding thermal-hydraulic performance, (0.8UN, 0.2ThN) exhibited outstanding performance with significant margins against fuel melting compared to the other materials. Overall, when considering the integrated performance, the most favourable results were obtained with the use of the (0.8UC, 0.2ThC) fuel configurations. This study contributes valuable insights into the potential benefits of (U, Th)-based ATFs as a promising avenue for enhanced nuclear fuel performance.

Keywords

• Accident-tolerant fuel
• Thorium-based fuel
• VVER-1200
• Carbide fuel
• Nitride fuel