LAICA - Linking Academia to Industry in Criticality safety Analysis

Project title: LAICA – Linking Academia to Industry in Criticality safety Analysis
Main applicant: Erik Andersson Sundén, Division of Applied Nuclear Physics
Co-applicants: Henrik Sjöstrand, Division of Applied Nuclear Physics
Grant amount: SEK 5 000 000 for the period 2024-2027

Criticality safety ensures no criticality events occur outside the nuclear reactor. There are many variables influencing criticality safety, and it is essential to fully understand their associated uncertainties. This understanding ensures that a reliable safety protocol can be followed without adding unnecessary conservative margins that come with cost and operational penalties.

The primary objective of this project is to develop a new methodology for criticality safety analysis throughout the operation of the nuclear fuel cycle. This initiative seeks to bolster the safety and reliability of nuclear power generation in Sweden by systematically examining the uncertainties related to criticality safety. This pertains to fuel operations at OKG, Ringhals, and Forsmark, as well as the Westinghouse nuclear fuel fabrication. This development also relates to a move from a conservative methodology to a best estimates plus uncertainty (BEPU) methodology.

Enhancing precision and reducing conservatism in criticality safety analyses are crucial in today’s nuclear fuel cycle, especially as we move towards higher enrichment levels. This transition is expected to reduce unnecessary conservative safety margins, making criticality safety assurance more challenging. This project is strategically positioned to address these challenges, laying the groundwork for the future safe implementation of higher enrichment fuels.

This project will investigate the propagation of uncertainties from nuclear data and other engineering parameters to criticality. This will be based on a BEPU methodology. Moreover, a novel method will be introduced to better utilize information from criticality benchmarks. This will assign more relevant margins in criticality safety and, by doing so, both increase safety and reduce operational penalties.

This project aims for rapid progress based on prior research from Uppsala University and Westinghouse. It will be executed as a PhD project at Uppsala University in partnership with Westinghouse.