ML19196A273

NEI Letter Providing Draft SE Comments to EPRI Topical Reports 3002010613 and 3002010614

ML19196A273
Person / Time
Site:	Nuclear Energy Institute, 99902028
Issue date:	01/31/2019
From:	Ashkeboussi N Nuclear Energy Institute
To:	Mirela Gavrilas Office of Nuclear Reactor Regulation
Shared Package
ML19168A097	List: ML19189A111 ML19189A112 ML19196A273 ML19196A274 ML19196A275 ML19196A276 ML19196A277 ML19196A302
References
3002010613, 3002010614
Download: ML19196A273 (2)

Text

NIMA ASHKEBOUSSI Director, Fuel Cycle Programs Fuel and Radiation Safety 1201 F Street, NW, Suite 1100 Washington, DC 20004 P: 202.739.8022 nxa@nei.org nei.org January 31, 2019 Dr. Mirela Gavrilas Director, Division of Reactor Safety Systems Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Submittal of Reactivity Decrement Bias and Uncertainty Values Using Linear versus Quadratic Weighted Least Squares Regression Models, Comments on Revised Draft Safety Evaluation Report for Electric Power Research Institute Reports Benchmarks for Qualifying Fuel Reactivity Depletion Uncertainty - Revision 1 and Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation - Revision 1, and Proposed Changes for the EPRI Utilization Report Project Number: 689

Dear Dr. Gavrilas:

On behalf of the Nuclear Energy Institutes (NEI) 1 members (hereinafter referred to as industry), please see the attached comments to the revision of the updated U.S. Nuclear Regulatory Commission (NRC) draft Safety Evaluation (SE) for the Electric Power Research Institute (EPRI) reports Benchmarks for Qualifying Fuel Reactivity Depletion Uncertainty - Revision 1 2, and Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation - Revision 13. NEI previously submitted comments 4 on the initial NRC draft SE5 on June 26, 2018. Additionally, in Attachment 1, we are submitting the uncertainty and bias values using linear versus quadratic weighted least squares regression models. We would specifically like to reiterate that the uncertainty values outlined in Attachment 1 did not change between the linear and quadratic regression approaches, but there was a change in the bias values, which is added as an additional NRC safety margin to the final analysis, per our discussion during the December 20, 2018 public meeting. In Attachment 3, we 1

The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.

2 EPRI report 3002010613, Benchmarks for Qualifying Fuel Reactivity Depletion Uncertainty, Revision 1 dated October 2017 (ML18088B397) 3 EPRI report 3002010614, Utilization of the EPRI Depletion Benchmarks for Burnup Credit Validation, Revision 1, dated January 2018 (ML18088B395) 4 Letter from B. Holtzman (NEI) to B. Benney (NRC), Submittal of Comments on Draft Safety Evaluation Report for Electric Power Research Institute Reports June 26, 2018.

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Dr. Mirela Gavrilas January 31, 2019 Page 2 are submitting the proposed changes to the EPRI Utilization report to reflect this position. The attachments to this letter contain industrys detailed comments and analysis.

We appreciated the opportunity afforded to industry during the December 20, 2018, public meeting to discuss the draft SER, understand NRC concerns, resolve misunderstandings, and identify a path forward for closing this issue. As you know, NEI and industry have been working with the NRC for over seven years to establish regulatory guidance that may be used by the industry to perform criticality analyses for the storage of spent fuel at light water power plants. Based on the public meeting, we believe that the attachments and industrys comment on the draft SER have sufficiently incorporated the NRC staffs feedback. Given the long history of this issue, we believe it would be beneficial to review a final draft prior to publication to ensure that all changes reflect our mutual understanding and goal to have an SER that is both clear and usable.

Finalization of the NRC SER in a timely manner is important to appropriately revise the EPRI reports that contain the important scientific and technical underpinnings that inform NEI 12-16, Guidance for Performing Criticality Analyses of Fuel Storage at Light Water Reactor Plants, Revision 3. 6 These EPRI reports are incorporated into NEI 12-16 by reference. The targeted NRC completion date of the third quarter of fiscal year 2019 would be helpful in achieving industrys objectives.

Thank you for your continued attention on this important matter. Please contact me if you have any questions or require additional information.

Sincerely, Nima Ashkeboussi : Evaluation of depletion reactivity decrement biases and uncertainty : Draft SER Comments : Proposed changes for the EPRI Utilization Report c: Ms. Louise Lund, NRC/NRR Mr. Dennis Morey, NRC/NRR Mr. Robert Lukes, NRC/NRR Mr. Jason Drake, NRC/NRR 6

NEI 12-16, Guidance for Performing Criticality Analyses of Fuel Storage at Light Water Reactor Plants, Revision 3 dated March 29, 2018 (ML18088B400)