Revolutionizing LWR SMR reactors: exploring the potential of (Th-²³³U-²³⁵U)O₂ fuel through a parametric study

ABSTRACT

Small modular reactors (SMRs) have garnered significant attention for their operational adaptability and ease of deployment. Thorium, with its well-documented advantages, shows promise as a viable fuel option for SMRs. However, the absence of intrinsic fissile components in thorium necessitates the exploration of different thorium-based fuel combinations. One such combination, (Th-²³³U)O₂ fuel, has limitations due to the presence of pure U-233. To overcome this challenge, a new fuel mixture, (Th-²³³U-²³⁵U)O₂, was investigated for SMRs. This study examined the reactor physics characteristics of the (Th-²³³U-²³⁵U)O₂ fuel, including fuel burnup, neutron flux spectra, power distribution, the evolution of actinides, and reactivity coefficients. Results indicate that the (Th-²³³U-²³⁵U)O₂ fuel allows for a longer criticality period compared to UO₂ fuel, with up to a 14% improvement, while accumulating fewer plutonium and transuranic elements. Notably, it demonstrates significantly improved negative reactivity coefficients, particularly for moderator temperature, with an average improvement of 45% over (Th-²³³U)O₂ fuel. The conceptual (Th-²³³U-²³⁵U)O₂ fuel, therefore, exhibits promising neutronic properties, presenting possibilities for future studies. These findings contribute to the understanding and advancement of advanced fuel designs for SMRs.

KEYWORDS:

• SMR
• Thorium
• Neutronic characteristics
• Criticality period
• Reactivity coefficients

Disclosure statement

The authors confirm that they have no known financial or personal conflicts of interest that could have influenced the integrity of the research presented in this paper.

Additional information

Notes on contributors

Mohamed Lkouz

Mohamed Lkouz is a doctoral student at Mohammed V University, Morocco. His current research focuses on exploring advancements in energy technologies and the field of nuclear engineering.

Ouadie Kabach

Ouadie Kabach is an active researcher who received his Ph.D. degree from Mohammed V University, Morocco. His research interests encompass simulations, nuclear reactor physics, neutron transport calculations, high-performance computing, and advanced nuclear system design. He also specializes in sensitivity and uncertainty analysis. Additionally, he demonstrates a keen interest in nuclear security and physical protection systems.

Abdelouahed Chetaine

Abdelouahed Chetaine is a full professor at Mohammed V University in Morocco, specializing in the field of nuclear physics. His research primarily focuses on nuclear simulations, verification, and validation. Additionally, he has a strong interest in nuclear security.

Abdelmajid Saidi

Abdelmajid Saidi is a full professor at Mohammed V University in Morocco, specializing in the field of nuclear physics. His research primarily focuses on nuclear simulations, verification, and validation.

Taoufiq Bouassa

Taoufiq Bouassa is a doctoral student at Mohammed V University, Morocco. His research is centered around exploring advancements in energy technologies, with a particular emphasis on nuclear engineering.