Licensing of new fuel products requires a rigorousand methodical approach to design, qualification, andlicensing to ensure high standards of fuel performanceare maintained. Duke Energy will complete irradiation ofa 3rd cycle of lead fuel assembly (LFA) operation forGAIA, Framatome’s latest PWR fuel assembly design, inthe fall of 2019. Completion of this program ensuresGAIA is ready for batch implementation in US W17x17PWRs.The GAIA fuel assembly is an evolutionary designimprovement that combines the thermal performance ofmixing grid designs with the exceptional robustness of theHTP product line. In addition to the physical assemblydesign, the GAIA project has developed the advancedcritical heat flux correlation ORFEO as well as a GAIAspecificmechanical analysis methodology.While Framatome developed the GAIA fuel assemblydesign, the qualification of the product was done with thesupport of a technical advisory board consisting ofseveral US utility representatives led by Duke Energy.The involvement of these representatives was critical todesign and licensing activities. In addition, DukeEnergy’s planning and executing the project to irradiateLFAs is an essential part of this successful program.Duke Energy’s approach to managing this programincluded review and acceptance of the Framatome designand compatibility analyses, adjustments to the coreloading pattern to support insertion, and intermediateexamination of the LFAs.As with any change in plant licensing basis, adoptionof a new fuel assembly design opens an array of relevantregulatory concerns that may need to be addressed moreexplicitly than in past submittals. For the GAIA design,this included development of improved seismic analysismethods to address irradiation impacts on grid strength.In addition, Framatome has also invested in codes andmethods such as AREA and ARITA to accurately modeladditional phenomena that can be combined with GAIA tosubstantially increase safety analysis margins.Framatome’s other developmental activities are able toleverage these combined improvements to confidentlypursue further areas to bring value to US nuclear utilitiesincluding extended burnups and PROtect AccidentTolerant fuel features.This paper will review the GAIA fuel assembly designand Duke Energy’s approach to management of the LFAprogram. In addition, further developments for the GAIAproduct and companion codes and methods will beexplored to provide an overview of the value utilities canexpect from implementation of GAIA along with otherFramatome technologies.
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