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Industry Feedback on NRC Anlwr PRA Technical Acceptability White Paper
	ML21055A732
Person / Time
Site:	Nuclear Energy Institute
Issue date:	02/23/2021
From:	; Nuclear Energy Institute
To:	; Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation
	Williams D
References
	Download: ML21055A732 (14)
	v • d • e

©2021 Nuclear Energy Institute 3 Document provides a basic framework for endorsement of the ANLWR PRA Standard and NEI 20-09, providing potential users with a path to regulatory certainty Industry appreciates NRC staff effort to accelerate this process Appreciate endorsement of NEI 20-09 Stated document purpose should reflect that the existing commission policy and rules related to PRA are specific to power reactors and are not applicable to non-power reactors References to SAMDAs should be eliminated due to lack of applicability of SAMDAs for advanced technologies References to Level 3 PRA should be eliminated. This term is not appropriate for an ANLWR design Expectations for relative risk significance criteria should be removed General Observations

©2021 Nuclear Energy Institute 4 No clear basis for expectation of PRA at Construction Permit stage Detail is not available at this time No safety finding is made at this stage, PRA is not needed Screening criteria from the standard should be endorsed as well Comprehensive scope is sufficient to ensure relevant initiators are covered Screening assists in managing complexity of PRA Expectations for timing and scope of peer reviews Several listed stages will not have PRAs suitable for peer review Scope should be according to PRA availability and changes, not by design stage General Observations

©2021 Nuclear Energy Institute 5 Discussion of white paper revealed need for additional dialogue in several key areas outside the scope of the paper itself What PRA means for various technologies Use of a fully deterministic basis Use of PRA without use of the ANLWR PRA Standard Need for durable, visible guidance from NRC Common understanding critical to providing context of white paper Areas for Additional Dialogue

©2021 Nuclear Energy Institute 6 Page 7: For ANLWR applications that are based on the LMP guidance, the PRA is used to select licensing basis events, classify systems, structures and components (SSCs), and to inform the defense-in-depth evaluation.

is should be may be as this need not be required Page 8: Plant representation and PRA configuration control The listed definition doesnt address PRA configuration control.

Suggest eliminating.

Specific Comments

©2021 Nuclear Energy Institute 7 Page 8: The NRC staff expects that a PRA that supports implementation of the LMP guidance or other voluntary risk-informed applications (such as implementation of 10 CFR 50.69 for applicants that do not use the LMP guidance), will have an increased level of detail and plant representation.

Some ANLWRs will have a simplified safety case so additional detail (relative to LWRs) may not be necessary. This sentence should be eliminated.

Specific Comments

These references are not appropriate for this white paper/regulatory guidance.

The PRA owner may define and use core damage, but not all will.

Risk integration and risk significance criteria require quantification of event sequence consequences Page 10: Discussion on LRF LRF and LERF are intentionally not used in the standard and should not be used here.

Existing definitions of LRF and LERF are qualitative and difficult to apply to NLWRs Specific Comments

It is unclear what the purpose of this discussion is Page 12: Discussion on bounding site An application should only need to provide enough siting information to demonstrate that the site is bound by the bounding site analyses performed.

Specific Comments

SAMDAs are likely not in the scope for many ANLWRs and this is not an appropriate expectation Page 13: Commercial operations stage: The plant accrues operating experience; the PRA reflects the as-built, as-operated plant including plant-specific operating experience.

It is unclear what is meant by this. Is there an expectation that the PRA will be resubmitted?

Specific Comments

©2021 Nuclear Energy Institute 11 Page 13: OL application stage: The plant has been constructed and is ready to begin pre-operational testing; the PRA generally represents the as-built and as-to-be-operated plant but does not reflect plant-specific operating experience.

The plant has not necessarily been constructed at the OL stage.

The OL cannot be issued until the plant is largely constructed.

A defined time prior to fuel load could be a better expectation.

In this sentence, as-built should be as-to-be-built Specific Comments

©2021 Nuclear Energy Institute 12 Page 16: Type 5 SRs become applicable when plant-specific operating experience is first incorporated into the PRA; Type 4 SRs become not applicable Unclear on what the regulatory standing of this is Page 17: Discussion on use of relative and absolute criteria.

Standard gives flexibility for use of either criteria; requiring both types of criteria was never considered in the standards development or use Specific Comments

©2021 Nuclear Energy Institute 13 Page 18: Reference to Appendix B PRA is not subject to Appendix B Page 20: The industry-led technology-inclusive content of application project (TI-CAP) is developing proposed content for specific portions of the safety analysis report (SAR) that would be used to support an advanced reactor application. The TI-CAP portion of the SAR will be informed by the guidance found in the LMP guidance (NEI 18-04).

Change would to could - TI-CAP should not be required to be used by applicants for advanced reactor licenses Specific Comments

©2021 Nuclear Energy Institute 14 Appreciate opportunity to engage with NRC on draft white paper prior to development of regulatory guidance Several outstanding issues to be resolved in the coming months to support clear, durable regulatory guidance Conclusion

ML21055A732

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