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20 - Industry - Industry Perspective on Performance Monitoring
	ML23160A142
Person / Time
Site:	Nuclear Energy Institute
Issue date:	06/15/2023
From:	; Nuclear Energy Institute
To:	; NRC/NRR/DNRL/NPHP
References
	Download: ML23160A142 (1)
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Industry Perspective on Application of Performance Monitoring in Optimizing Inservice Inspections June 15, 2023

Industry Perspective on Performance Monitoring Optimizing inspections has and can be justified using various analytical methods with significant margins and no adverse impact on performance.

Performance Monitoring (PM), where applicable, can be implemented either on a station specific or industry wide bases.

Industry wide approach is more efficient and likely more effective by covering more varied configurations and conditions.

Purpose of Performance Monitoring RG 1.174, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis

Monitoring and trending performance characteristics to verify aspects of the underlying analyses, research, or bases for a requirement (e.g.,

measuring battery voltage and specific gravity, inservice inspection of piping)

PM employs examination techniques that monitor for specific failure or degradation mechanisms

Existing Industrywide PM Programs Several industrywide PM programs already employed that effectively support strong performance:

Boric Acid Corrosion Control (BACC) Programs Routine Engineering and Operations Walkdowns Fatigue Monitoring Programs PWR RCS Leakage Monitoring Systems Most novel failure mechanisms have been found by these existing industrywide performance monitoring programs

Industrywide PM for Optimizing Inspections Inherent Cadence of PM across the US PWR Fleet Matrix for postulated timing of alternative request applications and current operating license

Considers each component individually (SG, Pressurizer)

Combines components, considering all are low allow steel The included matrix illustrates the cadence and number of PM for future submittals

International units would provide additional data

US PWR Fleet Performance Monitoring Start of Next Plant Name Inspection Year US PWR Fleet - SG & PZR Performance Monitoring Interval 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 Diablo Canyon 1 2025 Diablo Canyon 2 2026 Ginna 2030 Comanche Peak 1 2031 = Next Inspection Period Point Beach 1 2031 Robinson 2 2031 SER Issued (7)

Comanche Peak 2 2034 Relief Request in Progress (19)

Oconee 1 2034 Oconee 2 2034 Point Beach 2 2034 Prairie Island 1 2034 Calvert Cliffs 1 2035 Based on every unit receiving Arkansas Nuclear 1 2035 D.C. Cook 1 2035 Oconee 3 2035 approval of alternative out to Prairie Island 2 2035 Watts Bar 1 2036 Millstone 2 2036 Calvert Cliffs 2 Beaver Valley 1 Saint Lucie 1 2037 2037 2037 end of license life.

Salem 1 2037 D.C. Cook 2 2038 Davis-Besse 2038 Farley 1 2038 Arkansas Nuclear 2 2039 North Anna 1 2039 North Anna 2 2041 Salem 2 2041 Sequoyah 1 2041 Farley 2 2042 McGuire 1 2042 Sequoyah 2 2042 Summer 2043 Catawba 1 2044 Catawba 2 2044 McGuire 2 2044 Saint Lucie 2 2044 Byron 1 2045 Callaway 2045 Waterford 3 2045 Millstone 3 2046 Palo Verde 1 2046 Wolf Creek 1 2046 Byron 2 2047 Palo Verde 2 2047 Shearon Harris 1 2047 Braidwood 1 2047 Beaver Valley 2 2048 Palo Verde 3 2048 South Texas 1 2048 Braidwood 2 2048 Vogtle 1 2048 South Texas 2 2049 Vogtle 2 2050 Seabrook 1 2051 Surry 1 2053 Turkey Point 3 2053 Surry 2 2054 Turkey Point 4 2054 Watts Bar 2 2056

Required Pressurizer Inspections Based on Binomial Distribution (From Slide No. 20 of NRC Presentation on April 27, 2023 - ML23114A034)

Analysis Inputs

61 PWRs in the US fleet -one pressurizer (PZR) per PWR

All units have previously inspected PZRs

All welds under consideration have similar materials, similar stresses, similar environments (in part handled by analyzing an inspection as full set per PZR)

A 5% population incidence of novel degradation, with a 90% probability of detecting at least one occurrence in a PZR sampled

Three 10-year inspection intervals under consideration Across US Fleet that is 183 required PZR inspections Using the binomial distribution, 45 inspections are required (41 inspections when Monte Carlo is used) -yielding about 25% of the ASME required inspections over the 30-year inspection interval or 15 inspection per 10-year inspection interval

Industrywide PM Approach In any 10-year window starting in 2030, from the proposed sequencing of periods for extended operation (new licensing period), there are more than the requisite 15 inspections. (Conservatively this is based on EVERY unit receiving relief until end of license life, which will not be the case.)

From 2030 to 2040 the US fleet will be conducting 28 inspections

> 15 inspection per binomial applied to fleet

From 2035 to 2045 the US fleet will be conducting 32 inspections

> 15 inspection per binomial applied to fleet

From 2040 to 2050 the US fleet will be conducting 30 inspections

> 15 inspection per binomial applied to fleet Similarly, this industrywide PM approach can be extended to steam generators and yield the requisite 25% of ASME required inspections

Summary and Conclusion PM is effective for specific failure mechanisms Industrywide PM programs, including international operating experience, provide additional indications of potential issues Postulated timing of applications for extension of these specific component inspections results in inherent PM across the US PWR Fleet that satisfy the binomial distribution to yield more than 25% of the ASME required inspections over the 30-year inspection interval Industrywide PM approach is more effective and efficient than plant-specific approaches

QUESTIONS?

ML23160A142

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