b'2.6 LWR COMPUTATIONAL ANALYSISReactor Performance and Safety Impacts of Increased EnrichmentPrincipal Investigator: Nicholas R. BrownTeam Members/ Collaborators: Joseph R. Burns, Richard Hernandez, Kurt A. Terrani and Andrew T. NelsonThe research analysisA systems, mainly higher fuel utilization, dvanced Fuels Campaign (AFC) is developing Accident Tolerantwhile ensuring that HALEU fuel in indicated that increasingFuel (ATF) materials capableLWRs does not introduce added safety fuel enrichmentof increasing the safety margins ofand reliability concerns throughout had no detrimentallight water reactors (LWRs) undertheir operational lifetime.To achieve impacts on reactivitydesign basis and beyond basis accidentthis, several high-level performance coefficients, and theconditions [1]. These materials offerindicators used in the research and rim effect impacts onenhanced reactor performance underapplications of pin-level lattice evalu-the distributions of Punominal conditions due to reducedations assessed several performance content, EOL burnup andhydrogen pickup in the advancedmetrics. Adding to the AFC knowledge HBS, as well as fissioncladding, which leads to the potentialbase, discharge burnup was the main gas are enhanced withfor higher achievable burnup (withreactor performance metric used to increasing enrichment.concomitant enrichment increase),assess the economic advantages of longer fuel cycle length, and better fuelHALEU fuel, coupled with involving utilization. We aimed to quantify theseveral fuel cycle evaluation and reactor performance, safety impacts,screening (E&S) evaluation criteria and fuel cycle implications of increasing(natural resource utilization, spent fuel pressurized water reactor (PWR) 235Umetrics, environmental impacts) to fuel enrichment beyond 5%. characterized the economic impacts Project Description: of increasing PWR fuel enrichment The technical objective of this research[3]. To evaluate the safety performance was to quantify high-level observationsof HALEU fueled LWRs, reactivity on the reactor performance and safetycoefficients (fuel and moderator impacts, as well as several fuel cycletemperature coefficients, soluble metrics associated with implementingboron coefficient) were evaluated as PWR fuel enrichments between 5-7%a function of fuel enrichment. The 235U. This research is helping thebenefits of the research can also add to nuclear industry reduce costs for thethe state-of-knowledge by addressing nations current and next generationissues associated with boron control reactors by leveraging the economicmechanisms, the effects on formation advantages of High Assay Low-Enrichedof high burnup structures (HBS), as Uranium (HALEU) fueled LWRwell as radial fission gas and plutonium isotopes contents as a result of incorpo-rating HALEU fuel cycles in PWRs.116 2020|AFC ACCOMPLISHMENTS'