The LWR Sustainability (LWRS) Program activities must support the timeline dictated by utility life extension decisions to demonstrate a lead test rod in a commercial reactor within 10 years. In order to maintain the demanding development schedule that must accompany this aggressive timeline, the LWRS Program focuses on advanced fuel cladding systems that retain standard UO2 fuel pellets for deployment in currently operating LWR power plants. The LWRS work scope focuses on fuel system components outside of the fuel pellet, allowing for alteration of the existing zirconium-based clad system through coatings, addition of ceramic sleeves, or complete replacement (e.g. fully ceramic cladding).
Through extensive literature reviews and conversations with stakeholders, the LWRS Trade-off Study team has identified preliminary fuel cladding technology performance criteria and categorized these criteria into three groups: critical performance criteria, desired performance criteria, and licensing criteria. Weights will be assigned based on input from stakeholders, nuclear industry experts, and the nuclear material science community. Advanced cladding technology options will be evaluated against one another based on these weighted parameters. Technologies will be selected for further development and testing based on the results of the evaluation. A discussion on the nuclear design trade-offs, accident performance, storage, economics, safety, and licensing capabilities offered by each competing technology is included in this Trade-off Study report as a basis for the performance criteria and technology selections.
The leading candidate technologies identified in this Trade-off Study include coated Zircaloys, SiC/SiC, SiC ceramic matrix composite / Zr-based alloy hybrids, advanced Zr-based alloys, and engineered stainless steel alloys. Potential benefits and drawbacks have been identified in this study to aid in technology selection for further development and testing. The information provided in this Trade-off Study can be used in conjunction with continued input from industry stakeholders, national laboratories, and the U.S. Department of Energy-Nuclear Energy (DOE-NE) to identify technologies warranting further development and testing through the LWRS program.