ML26013A091
| ML26013A091 | |
| Person / Time | |
|---|---|
| Site: | Electric Power Research Institute |
| Issue date: | 01/13/2026 |
| From: | Licensing Processes Branch |
| To: | |
| References | |
| EPRI Report 3002032184, EPID L-2025-LRM-0030 pre-app, EPID L-2025-TOP-0024 pre-fee, EPID L-2025-NTR-0003 post-fee | |
| Download: ML26013A091 (4) | |
Text
Enclosure f
REGULATORY AUDIT PLAN BY THE OFFICE OF NUCLEAR REACTOR REGULATION IN SUPPORT OF THE REVIEW OF EPRI REPORT 3002032184, U.S. INDUSTRY PERFORMANCE MONITORING INSPECTION PLAN FOR SELECT ASME CODE EXAMINATION ITEMS OF PWR STEAM GENERATORS AND PRESSURIZERS DECEMBER 2025 - JANUARY 2026 ELECTRIC POWER RESEARCH DOCKET NO. 99902021
1.0 BACKGROUND
By letter dated June 19, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25171A128), Electric Power Research Institute (EPRI) submitted Non-Destructive Examination (NDE) Technical Report titled U.S. Industry Performance Monitoring [(PM)] Inspection Plan for Select ASME [American Society of Mechanical Engineers]
Code Examination Items of PWR [Pressurized Water Reactor] Steam Generators [SGs] and Pressurizers [PZRs] (TR or the NDE Optimization TR) to the U.S. Nuclear Regulatory Commission (NRC) for review and approval. The PM Inspection Plan presents a comprehensive U.S. PWR fleet-wide inspection plan for the SG and PZR components to address the NRCs requirement for PM. By email dated July18, 2025 (ML25174A097), the NRC staff accepted the NDE Optimization TR for review.
By email dated December8, 2025 (ML25211A269), the NRC staff issued a regulatory audit plan to conduct an audit associated with the review of EPRI NDE Optimization TR in accordance with the Office of Nuclear Regulatory Reactor Office Instruction (OI) LIC-111, Regulatory Audits, Revision 2, effective October 1, 2024 (ML24309A281). The purpose of the audit is for the staff to gain a better understanding of EPRIs U.S. PWR-fleet-wide inspection plan for SGs and PZRs components to address the NRCs requirement for PM during the extended relief period.
The NRC staff is updating its audit plan to include specific questions for discussion in an Appendix to the audit plan.
Appendix A List of Audit Questions for Discussion During Breakout Session
- 1. Request to review the data underlying Tables 2 and 3 of TR 3002032184. Cursory review shows some lines appear to be inconsistent with NRC understanding of the number of inspections per interval.
- a. Example 1 - Diablo Canyon Steam Generators are reported as 7 "components inspected per interval. Primary side should be 5 (1x B2.31, 1x B2.32, 1x B2.40, 2x B3.130) and secondary side should be 10 (2x C1.10, 1x C1.20, 1x C1.30, 3x (or more) C2.21, 3x (or more) C2.22. Total of 15?
- b. Example 2 - Surry Pressurizers are reported as 4 components inspected per interval. The Surry SE (ML23073A191) covered the B2.11 and B2.12 pressurizer shell to head welds and pressurizer shell longitudinal welds.
Discounting those welds from the count, we would expect the count to be 6-7, (1x B2.21, 1x B2.22, 5x(ish) B3.110 nozzles).
- 2. Section 5.2.1 Page 28 #3 - The TR states that approximately ten components are inspected every year. Confirm this is individual examinations, not ten steam generators?
- 3. Section 5.2.1 Page 28 #5 - The TR states that exams can be divided within the assigned interval but also seems to limit the ability to divide them entirely. For a unit with four or more exams, perform at least two exams within one period of the prescribed period. But the Figure 14 and 15 example using Surry 1 shows 4 assigned examinations in the first period of the grey interval and then redistributes 3 exams to the third period. Is this contradictory? If not, what is the limitation trying to say?
- 4. Section 5.3 - The TR states that for future SG/PZR replacements, inspections in the first interval after replacement are mandatory. At least 38% of the ASME Code, Section XI-required inspections shall be performed following replacement using the logic...
- a. Is it the understanding of EPRI that the first round of inspections after component replacement fall under the first inspection interval category or the successive inspection intervals category of the IWB and IWC tables?
- b. Is the TR proposing that the interval inspections following a component replacement may be reduced from 100% to 38% (regardless of whether its treated as a first inspection interval or successive inspection interval)?
- c. If yes to 4.b, what is the rationale for allowing reduced inspections of a new component in an existing plant but requiring new plants to complete one standard ASME Code,Section XI interval per section 6.3?
- 5. Section 5.4 and 7 - Letter addendums will be prepared when PWR units request and receive approval for alternative inspection schedules for the subject SG and PZR components. Clarify why NRC approval would require updates to the PM plan? If PWR units request and receive relief in accordance with this TR, no updates should be required. Is this suggesting updates will be required if a PWR unit requests relief outside the scope of the PM plan?
- 6. Section 5.4 and 7 - Letter addendums will be prepared when PWR units deviate from the original inspection schedule. Define which original inspection schedule? Does this mean an addendum will be prepared when PWR units deviate from the currently active PWR fleet PM plan?
- 7. Section 6.1 - Broadly discuss how the results of an evaluation of new unacceptable service-induced will be shared with the industry and/or NRC?
- a. Specifically, if the degradation mechanism appears related to a component design choice shared by reactors from the same manufacturers.
- b. Specifically, if the degradation mechanism is novel.
- 8. Section 6.1 First Bullet - The TR states that additional examinations will be in accordance with IWB-2430/IWC-2430. Regarding the number of exams, these sections of the code state:
IWB-2430 - The additional examinations shall include an additional number of welds, areas, or parts included in the inspection item equal to the number of welds, areas, or parts included in the inspection item that were scheduled to be performed during the present inspection period.
IWC 2430 - The additional examinations shall include an additional number of welds, areas, or parts included in the inspection item equal to 20% of the number of welds, areas, or parts included in the inspection item that are scheduled to be performed during the interval.
Specify how many additional examinations the TR envisions will be performed (maybe by example).
- 9. Section 6.1 - The TR states "all PWR units at the same plant site shall revert to ASME Code,Section XI examination requirements for the remainder of the interval during which the unacceptable indications are identified."
- a. Discuss the value of making all units at one site revert to the code requirements vice making units of the same design at other sites inspect the component where the indication was found. This seems to presuppose the defect is driven by site conditions (e.g. water chemistry) rather than design or fabrication conditions. If an indication is found in the surge nozzle of ANO-2, are we more concerned about the SG tubesheet to shell weld at ANO-1 or about the surge nozzles at other Combustion Engineering (CE) units?
- b. Using the remainder of the interval significantly changes this condition if indications are found in the first vice third period of the interval. IWB-2420 requires successive examinations in the next three periods and IWC-2420 requires successive examination in the next period, regardless of interval. Would changing the timing from interval to period in the TR make this condition more consistent?
- 10. Section 6.1 - The TR states ASME Code,Section XI examinations shall resume no later than the first or second refueling outage following discovery... Recommend whether one or two refueling outages be used. If the TR doesnt specify, the default will presumably be two refueling outages.
- 11. Section 6.1 - The TR states if the unacceptable indication is identified during the current inspection interval, and no further unacceptable indications are identified during the resumption of ASME Code,Section XI examinations, then the PM plan may continue to be applied for the subsequent inspection interval for all units at the plant site. As with 9.b above, this condition might be clearer with more detailed discussion of the timing.
E.g. If an indication is found in the first period, the plant reverts to the ASME Code Section XI requirements for two periods and then gets to return to the PM plan? If an indication is found in the third period, no additional inspections are required during that interval?
- 12. Section 6.2 - The TR states that...application of this PM plan shall be addressed in the plant-specific license renewal application... Mixing regulatory actions like a 10 CFR 54 license renewal and a 10 CFR 50.55a alternative request is generally not tenable.
Further, Sections 5.4 and 7 of the TR state that the PM plan will be updated a year prior to the license renewal or expiration of three plants in a calendar year. Since license renewals are generally submitted years in advance, and a license renewal may be one of only one or two in a given year, it seems likely some units will not have an updated fleet-wide PM plan to cite in their license renewal applications.
- 13. Section 6.3 - Plants with a shutdown period greater than three years must complete one ASME Code,Section XI interval inspection before incorporation into the fleet-wide PM program. Does the reason for shutdown matter? (i.e. recovering from an accident vs decommissioning and return to service?) One assumes system maintenance occurred, and the other does not.
- 14. Section 6.3 - If a plant submits an alternative request to use any of Reference 2, 3, 4, or 5 TRs outside of the fleet-wide PM, are they barred from participation in the fleet-wide PM until completion of one complete ASME Code,Section XI interval inspection?
- a. For new plants, would admission be limited to completion of inspections in the first inspection interval category of the IWB and IWC tables?
- 15. Section 6.4 - The TR notes that a standardized Request for Alternative submittal template will be prepared by EPRI. Although not required for a regulatory finding, can this form be shared during the audit? The use of a standard template like those found in Appendix A-1 and Appendix A-2 of WCAP-16168-NP-A Rev. 3 has been useful in increasing the efficiency of NRC review. The NRC may be able to offer informal comments to the template to increase the efficiency of future alternative requests.
- 16. Section 7 - The wording each PWR unit would perform 38% of the required ASME Code,Section XI examinations is a bit misleading even with the context of the next sentence. Would it be clearer to state that each Group 2 PWR unit participating in the fleet-wide PM plan would perform 38%...