ML16104A382
| ML16104A382 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/26/2016 |
| From: | Dominion |
| To: | Office of Nuclear Reactor Regulation |
| Sreenivas V | |
| References | |
| Download: ML16104A382 (9) | |
Text
North Anna Power Station New Fuel Storage Rack and Spent Fuel Pool Criticality Analysis Proposed License Amendment Request NRC Pre-Submittal Meeting April 26, 2016
Agenda
- Proposed Changes
- Analysis Goals
- Criticality Analysis Checklist
- Conservatism
- Conclusion/Timeline 2
2
Current NAPS SFP Configuration
- One rack cell design, 4.6 w/o U-235 maximum enrichment, 1737 total cells
- Flux-trap with Boraflex, 10.56 inch pitch
- No credit for Boraflex
- Credit for soluble boron
- Region 1 (4 out of 4 storage, one burnup curve)
- Region 2 (5x5, one empty cell, one burnup curve)
- Cell blocker in center cell 3
3
Current NAPS SFP Configuration (contd.)
- Current Region 2 (5x5) 4 4
Proposed Changes
- Increase enrichment limit to 5.0 w/o U-235
- Enhance core design flexibility
- Simplify Region configuration
- Region 1
- 2 out of 4 storage, no burnup requirement
- Region 2
- 4 out of 4 storage
- One burnup curve for low decay time
- One burnup curve for 3 year decay time
- No installed neutron absorber credit 5
5
Analysis Goals
- Incorporate recent criticality issues and improvements
- Increase identified margin
- Consistent with the Criticality Analysis Checklist 6
6
Criticality Analysis Checklist*
- Follows expected criticality analysis report format
- Includes placeholders for analysis Scope, Methods, and Details
- Shaded bars indicate major Sections
- Indentation indicates a subtopic
- Element within a topic or group
- Indicates some elements NOT included or NOT applicable
- Justification or explanation provided 7
- Previously provided to NRC Staff; Available upon request
Conservatism
- NRC administrative margin of 0.01 K reserved to account for minor current and/or emergent methodology issues and uncertainties
- Identify Dominion retained margin to allow for future design changes and/or methodology issues 8
8
Conclusion / Timeline
- A North Anna SFP and new fuel rack criticality analysis License Amendment Request will seek to increase maximum fuel enrichment, simplify storage configurations, and increase identified margin to keff limits
- Major milestones:
- Submit LAR to NRC Sept 2016
- Receive SER Sept 2018
- Shuffle fuel 4 Q 2018
- Implement new TS 4 Q 2018 9
9
North Anna Power Station New Fuel Storage Rack and Spent Fuel Pool Criticality Analysis Proposed License Amendment Request NRC Pre-Submittal Meeting April 26, 2016
Agenda
- Proposed Changes
- Analysis Goals
- Criticality Analysis Checklist
- Conservatism
- Conclusion/Timeline 2
2
Current NAPS SFP Configuration
- One rack cell design, 4.6 w/o U-235 maximum enrichment, 1737 total cells
- Flux-trap with Boraflex, 10.56 inch pitch
- No credit for Boraflex
- Credit for soluble boron
- Region 1 (4 out of 4 storage, one burnup curve)
- Region 2 (5x5, one empty cell, one burnup curve)
- Cell blocker in center cell 3
3
Current NAPS SFP Configuration (contd.)
- Current Region 2 (5x5) 4 4
Proposed Changes
- Increase enrichment limit to 5.0 w/o U-235
- Enhance core design flexibility
- Simplify Region configuration
- Region 1
- 2 out of 4 storage, no burnup requirement
- Region 2
- 4 out of 4 storage
- One burnup curve for low decay time
- One burnup curve for 3 year decay time
- No installed neutron absorber credit 5
5
Analysis Goals
- Incorporate recent criticality issues and improvements
- Increase identified margin
- Consistent with the Criticality Analysis Checklist 6
6
Criticality Analysis Checklist*
- Follows expected criticality analysis report format
- Includes placeholders for analysis Scope, Methods, and Details
- Shaded bars indicate major Sections
- Indentation indicates a subtopic
- Element within a topic or group
- Indicates some elements NOT included or NOT applicable
- Justification or explanation provided 7
- Previously provided to NRC Staff; Available upon request
Conservatism
- NRC administrative margin of 0.01 K reserved to account for minor current and/or emergent methodology issues and uncertainties
- Identify Dominion retained margin to allow for future design changes and/or methodology issues 8
8
Conclusion / Timeline
- A North Anna SFP and new fuel rack criticality analysis License Amendment Request will seek to increase maximum fuel enrichment, simplify storage configurations, and increase identified margin to keff limits
- Major milestones:
- Submit LAR to NRC Sept 2016
- Receive SER Sept 2018
- Shuffle fuel 4 Q 2018
- Implement new TS 4 Q 2018 9
9