Severe Accidents

Accident Tolerant Fuels to Support Power Uprates in LWRs (2024-2027)

Power uprates in Light Water Reactors (LWRs) have been used by U.S. utilities to increase their cost effectiveness by producing more electricity with a nominal cost increase. With the approval of the Inflation Reduction Act in 2022, there is a real economic incentive to boost nuclear energy production through ample power uprates using low 5-10% enriched uranium plus (LEU+) fuel and higher burnups (up to 75 GWd/tU peak rod average burnup). The superior material behavior and corrosion-resistant properties of near-term (e.g., Doped UO2 and coated Zr-alloy) and long-term (e.g., SiC and FeCrAl cladding) accident tolerant fuels (ATFs), make it possible to allow power uprates in LWRs beyond the current levels; it requires, however, in-depth operational and safety analyses to evaluate potential impacts.

The proposed research will result in the expansion of the state of knowledge in the use of ATF materials to support power uprates in LWRs while coupled with fuel enriched up to 10% and qualified for use at higher burnup levels. This project concurs with the industry goals to deploy ATF materials with increased enrichment and higher burnup to i) enhance safety performance, ii) improve plant economics, iii) increase fuel efficiency, and iv) decrease waste production.

PI: Juliana Pacheco Duarte (UW-Madison)

Co-PIs: Ben Lindley and WooHyun Jung (UWMadison), Jason Hou (NCSU), Robert Armstrong and Svetlana Lawrence (INL), David Lyle Luxat (SNL), Kolton Urso and Dale Bradish (Constellation), Maupin Keith (Framatome), Russell Stachowski (GNF)

Funding source: U.S. DOE – NEUP

ATF Solutions to Light Water-Cooled SMRs (2022-2025)

Fuel is the heart of all the nuclear reactor systems where the defense-in-depth principles and safety systems are designed around it. While traditionally treated as a low-cost item as part of the nuclear power plant’s total cost, nuclear fuel dictates the reactor power density and the nuclear island construction requirements (e.g. containment size to prevent radioactivity release from fuel). The increasing of power density of SMRs could be critical to its economic viability to overcome the lack of economy of scale. Indeed, a logical area of economic opportunity for ATFs is increase in core power density (e.g. power uprates) given their high-temperature capability. The objective of the proposed work is to: (1) Investigate near-term opportunities of accident tolerant fuels for light water-cooled small modular reactors (LWR-SMR) design spaces with Holtec’s SMR-160 as the reference plant for the US university partners and Rolls-Royce’s UKSMR as the reference plant for UK university partners (2) Simulate the fuel and safety performance of Lightbridge concept for the NuScale SMR (3) Provide scoping analysis of promising longer term advanced fuel forms to improve the safety and economics of LWRSMRs. (4) If the first 3 objectives have been addressed ahead of schedule, we will extend the work to GEH’s BWRX-300.

PI: Prof. Koroush Shirvan (MIT)

Collaborators: Michael Corradini (UW-Madison), Prof. Juliana P. Duarte (UW-Madison), Guillaume Giudicelli (INL), Kenny Anderson (NuScale Power), Faisal Odeh (Holtec), Russ Fawcett (GNF), Aaron Totemeier (Lightbridge Corporation), Eugene Shwageraus (University of Cambridge, UK), Michael Bluck (Imperial College, UK), Oliver Max Hannant (Rolls-Royce, UK)

Funding source: U.S. DOE – NEUP