Accident tolerant fuel: Benefits analysis for AOOS and DBAS

Accident Tolerant Fuel (ATF) is defined as a fuel form with improved material response during severe accidents and design basis accidents while maintaining or exceeding normal reactor operational performance when compared to current fuel technologies, such as uranium dioxide fuel pellets enclosed by a zirconium-based alloy clad. Prior to deployment, it is critical to assess the economic viability of accident tolerant fuel by conducting a comprehensive safety benefits evaluation informed by research, development and demonstration studies. EPRI and NEI have been leading the industry to define safety benefits of Accident Tolerant Fuel concepts. This work resulted in a summary of findings by the NEI Economics and Safety Benefits Task Group. This work is being extended with a collaboration between EPRI and Framatome, Inc. to evaluate the effects of near term ATF concepts on selected Anticipated Operating Occurrences (AOOs) and Design Basis Accidents (DBAs). This work concludes that transient events, which are limited by the Minimum Departure from Nucleate Boling Ratio (MDNBR), the results for Cr-Cr2O3 and the Standard M5^®/UO2 Fuel Systems are effectively the same. However, these results also show that if the MDNBR acceptance criterion is replaced by a failure mechanism based on cladding strength, then opportunities exist to alter plant operations for economic gains with the implementation of coated cladding.