ML24318C512
| ML24318C512 | |
| Person / Time | |
|---|---|
| Issue date: | 11/13/2024 |
| From: | Michael Mahoney NRC/NRR/DORL/LPL4 |
| To: | |
| References | |
| Download: ML24318C512 (11) | |
Text
PowerUpratePublicMeeting November14,2024 NRCStaffGradedApproachforPower UprateReviews
WorkingGroupPreliminary Recommendations The working group is looking for ways to focus the uprate reviews on the most safety and risk significant portions of the application.
This graded approach will enable the staff to evaluate the extent to which the power uprate changes impact important to safety structures, systems, and components (SSCs) functions and requirements.
- Associated with the applicable sections of NUREG-0800,Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR [Light-Water Reactor] Edition, (or SRP) (ML070810350).
To do this, three categories of reviews will be used to grade the expected level of effort commensurate with its safety and risk significance and the degree to which the Power Uprate affects them.
BinningTechnicalReviewAreas
- AreasofReviewfromNRCReviewStandard(RS)001,Review StandardforExtendedPowerUprates
- PubliclyAvailable ML023610659.
- NoteRS001isusedforStretchPowerUpratereviews.
- WorkingGroupdevelopedthreebins.
- Workingtocontinuetorefinethebinningstrategy.
BinningConsiderations During the working group review, the PRA staff determined that there is small percentage (approximately 30%) of the Power Uprate-related SRP sections are risk amenable (i.e., those that impact core damage frequency or large early release frequency).
The working group is evaluating if binning may be further refined by consideration of identified risk insights provided by the PRA staff, principles of defense-in-depth and safety margins, and other relevant factors such as operational experience and knowledge of past reviews.
Designbasis(valuesor assumptions)changes ORChangeinhowNRC regulationsaremet RisksignificantOR Significantchangein marginORSignificant changeinDIDORNear regulatorylimits UsingNRCapproved methodologiesANDNo deviations BIN3 Y
Y N
N BIN1/2 N
BIN1 BIN2/3 Y
Bin1
- Definition-Reviewareaswhichareexpectedtorequireminimal staffreviewefforts.
- This category includes review areas (or systems) that are not subject to impact by a Power Uprate because the Power Uprate will not likely effect system design or operation.
Examples - hazards (flood protection, equipment and floor drainage systems, light and heavy load handling systems, internally generated missiles), compressed air systems, various non-safety-related plant heating, ventilation, air conditioning systems.
Bin2
- Definition-ReviewareasthatareaffectedbyaPowerUprate,need tobereviewedagainstNRCregulations,butunlikelytohavea significantimpactonnuclearsafety.
- This category includes review areas (systems) that may be impacted by a power uprate due to potential changes in system design or operating conditions but would have little to no impact on plant safety since conditions are not expected to exceed the design parameters (pressure, temperature, flow, etc.) for the SSCs.
Examples: Some safety-significant support systems, certain reactor and containment review areas, certain accident analyses.
Bin3
- Definition-Reviewareasthataredirectlyimpactedbyoperationat upratedpoweranexpectedtorequireadetailedreviewbythestaff.
- This category includes review areas (systems) that are impacted by the power uprate:
- Result in significant changes to the systems design and analyses or operation
- Risk significant
- Significant change in margin
- Significant change in defense-in-depth (DID)
- Near regulatory limits
- Deviation from NRC-approved methodologies Examples: Some safety-significant support systems, certain reactor and containment review areas, certain accident analyses.
NRCStaffReview Bin 1 If the NRC staff determines that are no impacts on the review area based on information provided by the licensee, the safety evaluation will confirm that the power uprate will have no impact on the review area, and the associated regulatory requirements will continue to be met.
- The safety evaluation for these sections could be potentially reduced to a single section listing the review areas covered by this category in a table, with a short writeup indicating the staffs finding that the systems included in the table were not impacted by the uprate and compliance with the regulations were not affected.
Bin 2 If the changes are bounded by the current analysis, the staff will review to verify and no further review would be required; however, if the review is not bounded by current operation or analysis, or if there are major system modifications or upgrades, the staff will review the system and/or analysis results for compliance to the applicable regulations.
Bin 3 Detailed review of these areas will be planned to be conducted in accordance with the guidance in RS-001.
KeyMessages Nochangeforstaffsreviewtoconclude that:
- Thereisreasonableassurancethatthehealthandsafetyofthepublicwillnotbe endangeredbyoperationintheproposedmanner.
- Thereisreasonable assurancethatsuchactivitieswillbeconductedincompliance withtheNRC'sregulations.
- Theissuanceoftheamendmentwillnotbe inimical tothecommondefenseand securityortothehealthandsafetyofthepublic.
WGcontinuestorefinethebinningstrategy.
BinningisatoolforthestafftoprovideamoreefficientreviewofPower Uprateapplications.
Licenseesaretoprovidesufficientinformationforstafftodetermine whichbinandlevelofeffortofreview.
Areviewareasbinmaychangebasedonstaffreview.
WGEffortstoDate/NextSteps
- WGEffortstoDate
- PreliminaryRecommendationsMemo
- EPUSignatureDelegationMemo
- InitialstagesofAdvisoryCommitteeonReactorSafeguards(ACRS) engagementonfuturepowerupratereviews.
- PublicWebsiteupdates
- PastrequestsforadditionalinformationupdatedforallavailableSPUsandEPUs.
- New public pageforrecentpublicmeetings onpowerupratesandkeyWGdocuments.
- FuturePublicEngagements
- DataValidationandReconciliation(DVR)Methodology
- OtherTopicalReportsusedforfutureuprateapplications.
- Bundlinglicensingactions
Questions/Comments