ML18122A150

Pre-Submittal Meeting for St. Lucie Nuclear Plant, Unit 2 - Spent Fuel Pool Criticality Analyses - April 30, 2018

ML18122A150
Person / Time
Site:	Saint Lucie
Issue date:	04/30/2018
From:	Nextera Energy
To:	Plant Licensing Branch II
Buckberg P H, NRR/DORL/LPL2-2, 415-1447
Shared Package
ML18122A240	List: ML18122A150 ML18122A195
References
EPID L-2018-LRM-0023
Download: ML18122A150 (25)

Text

Pre-Submittal Meeting for St. Lucie Unit 2Spent Fuel Pool Criticality AnalysesApril 30, 2018 2*Describe the planned scope and methodology for the proposed St. Lucie Unit 2 Spent Fuel Pool Criticality Analysis License Amendment Request-Partial criticality analysis for cask pit rack only*Seek feedback from NRC staffPurpose 3Agenda*Current Condition*New Criticality Analysis*Technical Specification Changes*Closing Summary 4*Safety Evaluation for St. Lucie Unit 2 Spent Fuel Pool Criticality Analysis LAR was issued in September 2012 (ML12263A224)oAnalysis was performed in support of Extended Power Uprate project*Analysis performed with CASMO-4 and MCNP5 *Analysis complies with DSS-ISG-2010-01Current Condition -SFP Criticality Analysis 5Current Condition -Spent Fuel Pool*Analysis covers three regions in the St. Lucie Unit 2Spent Fuel PooloRegion 1oRegion 2 oCask Pit Rack38373635343332313029282726252423APAPCask Area RackANANC15C14C13C12C11C10C9C8C7C6C5C4C3C2C1AMAMCRCRALALCPCPAKAKCNCNAJAJCMCMAHAHCLCLAGAGCKCKAFAFCJCJAEAECHCHADADCGCGACACCFCFABABCECEZZZZCDCDYYYYCCCCXXXXCBCBWWWWCACATTTTC15C14C13C12C11C10C9C8C7C6C5C4C3C2C1SSSSRRRRPPPPNNNNRegion 2Region 1MM22212019181716151413121110987654321LLLLLLKKKKKKJJJJJJHHHHHHGGGGGGFFFFFFEEEEEEDDDDDDCCCCCCBBBBBBAAAAAAZZZYYYXXXWWWTTTSSSRRRPPPNNNMMMLLLKKKJJJHHHGGGFFFEEEDDDCCCBBBAAA3837363534333231302928272625242322212019181716151413121110987654321 6Current Condition -Technical Specifications*Technical Specifications contains allowable storage patterns for each region 7*Storage patterns included in criticality analysis were developed based on estimates for future storage needs under EPU conditions*Current storage patterns are not optimaloReliance on empty cells limits capacityoNot aligned with fuel storage needs under EPU conditionsCurrent Condition -Fuel Storage Limitations 8*NextEra Energy considered various options to improve storage capacityonew cask pit rackoadditional dry storage casksofull criticality re-analysispartial criticality analysisCurrent Condition -Options 9Agenda*Current Condition*New Criticality Analysis*Technical Specification Changes*Closing Summary 10*Our plan is to perform a partial criticality analysis that will fully replace the parts of the current analysis addressing the cask pit rack onlyoFollows precedent from Duane Arnold criticality analysis*All other parts of current analysis remain the sameoNo changes to current Technical Specifications for Regions 1 and 2*Partial criticality analysis will be performed in-house New Criticality Analysis 11*Partial criticality analysis will followoNRC Guidance DSS-ISG-2010-01, "Staff Guidance Regarding the Nuclear Criticality Safety Analysis for Spent Fuel Pools"oNEI 12-16, "Guidance for Performing Criticality Analyses of Fuel Storage at Light-Water Reactor Power Plants"*Codes will be PARAGON 1.2.0b and MCNP6.1 with ENDF/B-VII.1 cross section library*As for current analysis, the partial analysis will with 95% confidence / 95% probabilityNew Criticality Analysis 12*No significant changes or factors to addressoNo change in fuel designoNo change in operating conditionsoNo change in rack designoNo Boraflex*Will revalidate all analysis parametersoReactor depletion parametersoBoral areal densityoAxial burnup shapeNew Criticality Analysis 13*Will re-perform all analyses for cask pit rackoDesign basis assemblyoTolerancesoUncertaintiesoAccidentsoCode validation*No interfaces with Region 1 nor Region 2 will need to be addressedNew Criticality Analysis 14*New storage patterns have been preliminarily developedo3 out of 4 fresh assemblies, crediting integral burnable absorbero4 out of 4 irradiated assemblies with one CEA, burnup credito3 out of 4 irradiated assemblies, burnup credito1 fresh and 2 irradiated assembliesTo address interface between first two patternsNew Criticality Analysis1111FBAFBAFBA1FBA1 15*For the fresh fuel category crediting integral burnable absorber, it would require n number of rods at a minimum concentrationoIf condition is not met, fresh assembly would then be stored in current 2 out of 4 configuration in Region 1New Criticality Analysis 16*As done today for all NextEra Energy PWRs, PISCES code will be used as supplementary verification tooloAfter move plans are prepared and reviewed*PISCES codeoDetermines fuel category for all fuel assemblies & non-fuel itemsoTracks all inserts and panels (credited and non-credited)oEvaluates configuration/proposed moves against Technical Specification requirementsoProvides summary & graphical output filesNew Criticality Analysis -Implementation 17Agenda*Current Condition*New Criticality Analysis*Technical Specification Changes*Closing Summary 18*Technical Specification Figures 5.6-4, "Allowable Cask Pit Storage Rack Patterns," will be replacedoNew storage patterns, definitions and notes will be added*Technical Specification Table 5.6-1, "Minimum Burnup Coefficients," will be modifiedoValues for fuel type 8 will be modifiedoNew fuel types will be addedoValues for fuel types 1-7 will NOT be modifiedTechnical Specification Changes 19Technical Specification Changes 20Technical Specification Changes 21Agenda*Current Condition*New Criticality Analysis*Technical Specification Changes*Closing Summary 22*Schedule of LAR submittaloPlan to submit in December 2018*Summary of path forward*Review action itemsClosing Summary 23Backup Slides 24Current Condition -Fuel Storage Needs*Fresh fuel stored in 2 out of 4 configuration in R1 or CPR*Once burnt fuel stored in 3 out of 4 configuration in CPR*Twice burnt fuel stored in 3out of 4 configuration in any of the three regions 25Current Condition -Cask Pit Rack