ML21265A558

Attachment 5: Appendix C, NEI 12-16 Criticality Analysis Checklist

ML21265A558
Person / Time
Site:	LaSalle
Issue date:	06/30/2021
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
References
RS-21-064
Download: ML21265A558 (9)

Text

ATTACHMENT 5 NEI 12-16 Criticality Analysis Checklist

APPENDIX C: CRITICALITY ANALYSIS CHECKLIST The criticality analysis checklist is completed by the applicant prior to submittal to the NRC. It provides a useful guide to the applicant to ensure that all the applicable subject areas are addressed in the application, or to provide justification/identification of alternative approaches.

The checklist also assists the NRC reviewer in identifying areas of the analysis that conform or do not conform to the guidance in NEI 12-16. Subsequently, the NRC review can then be more efficiently focused on those areas that deviate from NEI 12-16 and the justification for those deviations.

Subject Included Notes / Explanation 1.0 Introduction and Overview Purpose of submittal YES Section 1.0 of NEDC-33931P and Section 1.0 of LAR RS-21-064 Changes requested YES Section 1.0 of NEDC-33931P and Sections 2.1, 2.2, 2.3, and 2.4 of LAR RS-21-064 Summary of physical changes YES Section 1.0 of NEDC-33931P and Sections 2.1, 2.2, 2.3, and 2.4 of LAR RS-21-064 Summary of Tech Spec changes YES Sections 2.3, 2.4 and Attachment 2 of LAR RS-21-064 Summary of analytical scope YES Sections 1.0 and 3.0 of NEDC-33931P and Sections 2.1 and 2.2 of LAR RS-21-064 2.0 Acceptance Criteria and Regulatory Guidance Summary of requirements and guidance YES Section 2.0 of NEDC-33931P and Sections 2.1 and 2.2 of LAR RS 064 Requirements documents referenced YES Section 2.0 of NEDC-33931P and Sections 2.1 and 2.2 of LAR RS 064 Guidance documents referenced YES Section 2.0 of NEDC-33931P and Sections 2.1 and 2.2 of LAR RS 064 Acceptance criteria described YES Section 2.0 of NEDC-33931P and Sections 2.1 and 2.2 of LAR RS 064 3.0 Reactor and Fuel Design Description Describe reactor operating parameters NO Not applicable for the NEDC-33931P analysis. See Sections 3.7 and 5.5 of C-1

NEDC-33931P for depletion parameters and assumptions.

Describe all fuel in pool YES Section 4.0 of NEDC-33931P Geometric dimensions (Nominal and YES Section 4.1 of NEDC-33931P Tolerances)

Schematic of guide tube patterns NO Not applicable for BWR fuel Material compositions YES Section 4.0 of NEDC-33931P Describe future fuel to be covered YES Section 4.0 of NEDC-33931P Geometric dimensions (Nominal and YES Section 4.1 of NEDC-33931P Tolerances)

Schematic of guide tube patterns NO Not applicable for BWR fuel Material compositions YES Section 4.0 of NEDC-33931P Describe all fuel inserts NO There are no fuel inserts in analysis Geometric Dimensions (Nominal and NEDC-33931P.

Tolerances)

Schematic (axial/cross-section)

Material compositions Describe non-standard fuel YES Section 4.0 of NEDC-33931P Geometric dimensions Describe non-fuel items in fuel cells YES Section 4.0 of NEDC-33931P Nominal and tolerance dimensions NO Not applicable; analysis NEDC-33931P covers peak reactivity in every rack cell location 4.0 Spent Fuel Pool/Storage Rack Description New fuel vault & Storage rack description YES The new fuel vault analysis will be Nominal and tolerance dimensions covered by the GESTAR II Schematic (axial/cross-section) methodology and is not addressed in Material compositions NEDC-33931P. See Section 2.2 of LAR RS-21-064 for details.

Spent fuel pool, Storage rack description YES Section 5.1 of NEDC-33931P and Nominal and tolerance dimensions Section 3.1 of LAR RS-21-064 Schematic (axial/cross-section)

Material compositions Other Reactivity Control Devices (Inserts) YES Sections 5.1-5.2 of NEDC-33931P and Nominal and tolerance dimensions Section 3.1 of LAR RS-21-064 Schematic (axial/cross-section)

Material compositions 5.0 Overview of the Method of Analysis New fuel rack analysis description YES The new fuel vault analysis will be Storage geometries covered by the GESTAR II Bounding assembly design(s) methodology and is not addressed in Integral absorber credit NEDC-33931P. See Section 2.2 of Accident analysis LAR RS-21-064 for details.

Spent fuel storage rack analysis description YES Sections 5.0, 3.5-3.7 of NEDC-33931P C-2

Storage geometries YES Sections 5.1-5.2 of NEDC-33931P Bounding assembly design(s) YES Section 5.3 of NEDC-33931P Soluble boron credit NO Not applicable - No soluble boron credit in this BWR criticality analysis Boron dilution analysis (NEDC-33931P)

Burnup credit NO No burnup credit in BWR peak reactivity analysis NEDC-33931P -

fuel is evaluated at peak reactivity Decay/Cooling time credit NO No decay/cooling time credit in analysis NEDC-33931P.

Integral absorber credit YES Sections 5.1-5.2 of NEDC-33931P Other credit NO No other credit in analysis NEDC-33931P.

Fixed neutron absorbers YES Boral panel (unit 1), insert (unit 2)

Aging management program NO Aging is not included in analysis NEDC-33931P; for Unit 2, no credit is taken for Boraflex. The potential for blistering on the Boral has been evaluated and the neutron absorber will continue to fulfill its function.

Accident analysis YES Section 5.5.3 of NEDC-33931P Temperature increase YES Sections 5.4-5.5 of NEDC-33931P Assembly drop YES Section 5.5.3 of NEDC-33931P Single assembly misload YES Section 5.5.3 of NEDC-33931P Multiple misload NO Uniform pool, no opportunity for multiple misload Boron dilution NO Not applicable - No soluble boron credit in this BWR criticality analysis (NEDC-33931P)

Other YES Section 5.6 of NEDC-33931P Fuel out of rack analysis YES Section 5.5 of NEDC-33931P considers Handling worst case abnormal positioning of a Movement fuel assembly outside the storage rack.

Inspection 6.0 Computer Codes, Cross Sections and Validation Overview Code/Modules Used for Calculation of keff YES Section 3.0 of NEDC-33931P Cross section library YES Section 3.1 of NEDC-33931P Description of nuclides used YES Section 4.2 of NEDC-33931P Convergence checks YES Section 3.3 of NEDC-33931P Code/Module Used for Depletion YES Section 3.0 of NEDC-33931P Calculation Cross section library YES Section 3.1 of NEDC-33931P Description of nuclides used YES Section 4.2 of NEDC-33931P Convergence checks YES Section 3.3 of NEDC-33931P C-3

Validation of Code and Library YES Section 3.4, Appendix A of NEDC-33931P Major Actinides and Structural YES Section 3.4 of NEDC-33931P Materials Minor Actinides and Fission Products YES Section 3.4 of NEDC-33931P Absorbers Credited YES Section 3.4 of NEDC-33931P 7.0 Criticality Safety Analysis of the New Fuel Rack Rack model YES The NFV rack CSA coverage for the Boundary conditions new GNF3 fuel will be the GESTAR II Source distribution analysis for GE designed low density Geometry restrictions NFV racks upon approval of this Limiting fuel design proposed license amendment. The Fuel density LSCS NFV racks are GE designed low Burnable Poisons density racks with an interrack spacing Fuel dimensions of 12.25 inches, which is 10.5 inches Axial blankets (the criteria listed in GESTAR II) and Limiting rack model thus the racks may be utilized to store Storage vault dimensions and materials new GNF fuel with in-rack SCCG kinf Temperature 1.31. See Section 2.3 of LAR RS 064 for details.

Multiple regions/configurations Flooded Low density moderator Eccentric fuel placement Tolerances Fuel geometry Fuel pin pitch Fuel pellet OD Fuel clad OD Fuel content Enrichment Density Integral absorber Rack geometry Rack pitch Cell wall thickness Storage vault dimensions/materials Code uncertainty Biases Temperature Code bias Moderator Conditions Fully flooded and optimum density moderator C-4

8.0 Depletion Analysis for Spent Fuel Depletion Model Considerations YES Sections 3.0, 3.3, 3.4, 3.7, and 4.2 of Time step verification NEDC-33931P Convergence verification Simplifications Non-uniform enrichments Post Depletion Nuclide Adjustment Cooling Time Depletion Parameters Burnable Absorbers Integral Absorbers Soluble Boron Fuel and Moderator Temperature Power Control rod insertion Atypical Cycle Operating History 9.0 Criticality Safety Analysis of Spent Fuel Pool Storage Racks Rack model YES Section 5.2 of NEDC-33931P Boundary conditions Source distribution Geometry restrictions Design Basis Fuel Description YES Section 5.3 of NEDC-33931P Fuel density YES Section 4.1 of NEDC-33931P Burnable Poisons YES Section 5.2 of NEDC-33931P Fuel assembly inserts NO No fuel assembly inserts in analysis NEDC-33931P Fuel dimensions YES Section 4.1 of NEDC-33931P Axial blankets NO Section 3.7 of NEDC-33931P Configurations considered YES Section 6.0 of NEDC-33931P Borated NO Not applicable for this BWR analysis (NEDC-33931P)

Unborated YES BWR analysis NEDC-33931P considers unborated SFP.

Multiple rack designs YES Section 5.1 for rack descriptions and Section 6.0 for rack interfaces.

Alternate storage geometry NO Not applicable for analysis NEDC-33931P Reactivity Control Devices YES Sections 5.1- 5.2 Fuel Assembly Inserts NO No fuel assembly inserts in analysis NEDC-33931P Storage Cell Inserts YES Sections 5.1- 5.2 of NEDC-33931P Storage Cell Blocking Devices NO No blocking devices in analysis NEDC-33931P Axial burnup shapes NO Section 3.7 of NEDC-33931P C-5

Uniform/Distributed YES Section 3.7 of NEDC-33931P Nodalization NO Section 3.7 of NEDC-33931P Blankets modeled NO Section 3.7 of NEDC-33931P Tolerances/Uncertainties YES Sections 5.6 and 5.7 of NEDC-33931P Fuel geometry Fuel rod pin pitch Fuel pellet OD Cladding OD Axial fuel position NO Section 3.7 of NEDC-33931P Fuel content YES Section 5.6 of NEDC-33931P Enrichment Density Assembly insert dimensions and NO No fuel assembly inserts in analysis materials NEDC-33931P Rack geometry YES Section 5.6 of NEDC-33931P Flux-trap size (width) NO Not applicable to non-flux-trap racks Rack cell pitch YES Section 5.6 of NEDC-33931P Rack wall thickness YES Section 5.6 of NEDC-33931P Neutron Absorber Dimensions YES Section 5.6 of NEDC-33931P Rack insert dimensions and materials YES Section 5.6 of NEDC-33931P Code validation uncertainty YES Sections 3.4, 5.7, and Appendix A of NEDC-33931P Criticality case uncertainty YES Section 5.7 of NEDC-33931P Depletion Uncertainty YES Sections 3.4, 5.8 of NEDC-33931P Burnup Uncertainty NO Not applicable for BWR peak reactivity analysis NEDC-33931P Biases YES Section 5.0 of NEDC-33931P Design Basis Fuel design YES Section 5.3 of NEDC-33931P Code bias YES Sections 3.4, 5.5 of NEDC-33931P Temperature YES Section 5.4 of NEDC-33931P Eccentric fuel placement YES Sections 5.4-5.5 of NEDC-33931P Incore thimble depletion effect NO Not applicable for analysis NEDC-33931P NRC administrative margin NO Not applicable for analysis NEDC-33931P Modeling simplifications YES Sections 3.7, 4.2 of NEDC-33931P Identified and described 10.0 Interface Analysis Interface configurations analyzed YES Sections 5.5, 6.0 of NEDC-33931P Between dissimilar racks YES Section 6.0 of NEDC-33931P Between storage configurations within YES Section 5.5 of NEDC-33931P a rack Interface restrictions NO Section 6.0 of NEDC-33931P C-6

11.0 Normal Conditions Fuel handling equipment NO Not in the scope and does not impact results of criticality analysis NEDC-33931P.

Administrative controls YES Section 2.4 and Attachment 2 of LAR RS-21-064 Fuel inspection equipment or processes NO Not in the scope and does not impact results of criticality analysis NEDC-33931P.

Fuel reconstitution YES Section 4.0 of NEDC-33931P 12.0 Accident Analysis Boron dilution NO Not applicable - No soluble boron Normal conditions credit in this BWR criticality analysis Accident conditions (NEDC-33931P)

Single assembly misload YES Section 5.5 of NEDC-33931P Fuel assembly misplacement YES Section 5.5 of NEDC-33931P Neutron Absorber Insert Misload NO Not applicable to this BWR analysis; no fuel assembly inserts in analysis NEDC-33931P.

Multiple fuel misloads NO Uniform pool, single storage configuration, no opportunity for multiple misloads Dropped assembly YES Section 5.5 of NEDC-33931P Temperature YES Section 5.4 of NEDC-33931P Seismic event/other natural phenomena YES Section 5.5 of NEDC-33931P 13.0 Analysis Results and Conclusions Summary of results YES Section 7.0 of NEDC-33931P NO Not applicable for BWR peak reactivity Burnup curve(s) analyses, including NEDC-33931P NO Not applicable for BWR peak reactivity Intermediate Decay time treatment analyses, including NEDC-33931P YES Section 2.4 and Attachment 2 of LAR New administrative controls RS-21-064 YES Sections 2.3, 2.4 and Attachment 2 of Technical Specification markups LAR RS-21-064 14.0 References YES Section 8.0 of NEDC-33931P Appendix A: Computer Code Validation: Appendix A of NEDC-33931P Code validation methodology and bases YES Appendix A of NEDC-33931P New Fuel Depleted Fuel MOX HTC Convergence C-7

Trends Bias and uncertainty Range of applicability YES Described in Section 3.4 of NEDC-33931P Analysis of Area of Applicability YES Described in Section 3.4 of NEDC-coverage 33931P C-8