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Latest revision as of 20:47, 20 January 2022
ML21032A255 | |
Person / Time | |
---|---|
Issue date: | 03/29/2021 |
From: | Eric Duncan NRC/NRR/DRO/IRIB |
To: | |
Duncan E | |
Shared Package | |
ML21035A135, ML21081A297 | List: |
References | |
CN 21-015, DC 21-003 | |
Download: ML21032A255 (8) | |
Text
NRC INSPECTION MANUAL IRIB INSPECTION PROCEDURE 71111 ATTACHMENT 04 EQUIPMENT ALIGNMENT Effective Date: July 1, 2021 PROGRAM APPLICABILITY: IMC 2515 A CORNERSTONES: Initiating Events Mitigating Systems Barrier Integrity INSPECTION BASES: See Inspection Manual Chapter (IMC) 0308, Reactor Oversight Process Basis Document, Attachment 2, Technical Basis for Inspection Program SAMPLE REQUIREMENTS:
Minimum Baseline Sample Requirements Completion Sample Budgeted Range Requirements Sample Type Section(s) Frequency Sample Size Samples Hours 12 per site 12-16 Partial Walkdown* 03.01 Annual 80 +/- 12 per 2 at Vogtle 2-4 at Vogtle site Units 3 & 4 Units 3 & 4 Annual 2 per site 2 8-40 at 0 at Vogtle Vogtle Units Complete Walkdown** 03.02 0-2 at Vogtle 3&4 Annual Units 3 &
Units 3 & 4***
4***
- Each partial walkdown sample is budgeted at 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
- Perform one complete walkdown sample approximately every 6 months. Each complete walkdown sample is budgeted at 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
- At least one complete Equipment Alignment inspection sample is required to be completed unless plant conditions or other circumstances impact sample performance.
71111.04-01 INSPECTION OBJECTIVES 01.01 To verify equipment alignment and identify any discrepancies that impact system safety function(s).
01.02 To verify that the licensee has properly identified and resolved equipment alignment problems that could cause initiating events or impact the availability and functional capability of mitigating systems or barriers.
Issue Date: 03/29/21 1 71111.04
71111.04-02 GENERAL GUIDANCE Select a reasonable distribution of partial walkdown samples each quarter and on each unit at multiple unit sites throughout the year.
With regard to sample selection, the most risk-significant system may not be the redundant or backup train (for example, the most risk-significant system could be the electrical bus that provides power to the redundant or backup train). If available, consider risk insights regarding significant initiating events for the given plant equipment configuration. Such insights should be used to assess the licensees awareness of the need for compensatory measures pursuant to Title 10 of the Code of Federal Regulations 50.65(a)(4). Refer to Inspection Procedure (IP) 71111.13, Maintenance Risk Assessments and Emergent Work Control, for more information.
The following tables provide general inspection guidance for sample selection.
Initiating Events Cornerstone Inspection Objective: Identify any equipment alignment discrepancies that could result in a risk-significant initiating event and impact the availability and functional capability of plant equipment.
Risk Priority Examples OperatingEquipment lineups affecting Maintenance which leaves only one operating initiating event frequencies or functional feed pump providing feed capabilities of plant equipment Instrument air lineup ShutdownEquipment lineups during System lineups during pressurized-water reactor special tests or evolutions (PWR) midloop operation or boiling-water reactor (BWR) vessel draindown Misalignment of electrical equipment during shutdown that could cause loss of offsite power and affect decay heat removal Mitigating Systems Cornerstone Inspection Objective: Identify any equipment alignment discrepancies that could impact the availability and functional capability of a risk-significant mitigating system.
Risk Priority Examples OperatingEquipment lineups following system Safety trains on the remaining restoration or equipment lineups that support another emergency bus when one emergency alternate system/train when a Maintenance Rule diesel generator (EDG) is out of system is out of service service or failed Issue Date: 03/29/21 2 71111.04
ShutdownEquipment lineups that affect shutdown Safety trains on the remaining risk or equipment lineups that support another emergency bus when one EDG is out alternate system/train when a Maintenance Rule of service or failed system is out of service Barrier Integrity Cornerstone Inspection Objective: Identify any equipment alignment discrepancies that could degrade the integrity of the fuel barrier, reactor coolant system, or containment.
Risk Priority Examples OperatingFuel cladding degradation can Reactivity control systems (e.g., BWR result from both inadequate human and recirculation pump controls, PWR loss-of-equipment performance. Reactivity control letdown response, rod drives, rod block systems must be properly configured to monitors, rod worth minimizers) prevent and/or mitigate adverse reactivity transients and neutron flux distributions. Containment isolation valves (e.g., containment purge valves)
ShutdownEquipment lineups that affect Containment configuration during risk-reactor coolant system inventory and significant evolutions (e.g., PWR midloop containment operation, BWR cavity draindown)
Spent fuel pool and alternate decay heat removal system (BWR only) operation Select systems or trains with a high risk significance for the current plant configuration (considering out-of-service, inoperable, or degraded condition); or a risk-significant system/train that was recently realigned following an extended system outage, maintenance, modification, or testing; or an out-of-service risk-significant system/train.
When selecting a system or train walkdown sample, consider the following:
- risk-informed insights from site-specific risk studies
- operator actions and access during potential accident sequences
- operating experience
- performance history
- equipment configuration (e.g., out of service, inoperable, or degraded)
- past walkdown samples
- recently realigned equipment following an outage, maintenance, modification, or testing Consider walking down a protected operable train when the other train is out of service.
For AP1000 designs, SSCs classified as regulatory treatment of non-safety systems (RTNSS) will be inspected consistent with how other nonsafety-related SSCs are inspected in currently operating plants. In currently operating plants, inspectors can select inspection activities involving nonsafety-related SSCs based on risk significance or on the potential for impact on steady-state plant operations in accordance with guidance contained in Inspection Procedure (IP) 71111, Reactor Safety-Initiating Events, Mitigating Systems, Barrier Integrity. Since licensing documents specifically discuss RTNSS SSCs for AP1000 plants, the staff has Issue Date: 03/29/21 3 71111.04
updated program guidance to clarify that RTNSS SSCs will be treated as any other nonsafety-related SSCs. Consistent with risk-informed principles, inspectors are expected not to routinely focus inspection resources on RTNSS SSCs and other nonsafety-related systems but rather examine these nonsafety-related systems when site activities make them samples of value consistent with the risk-informed sample selection guidance. As a practical example, the contribution to total plant risk for the RTNSS normal residual heat removal system is expected to be higher during outage periods. Using guidance from IP 71111 for risk-informed sample selection, it would be appropriate for inspectors to select the normal residual heat removal (RNS) system for sampling during periods of elevated RNS risk importance.
For each sample, routine review of problem identification and resolution activities should be conducted using IP 71152, Problem Identification and Resolution.
71111.04-03 INSPECTION SAMPLES 03.01 Partial Walkdown Sample Walkdown and verify that the critical portions of a selected system/train are correctly aligned.
Specific Guidance
- a. Review documents to determine the correct system/train lineup for the selected system/train. Consider plant procedures; abnormal and emergency operating procedures; the updated final safety analysis report; vendor technical manuals; piping and instrument drawings; valve, switch, and breaker lineups; and plant tagout logs.
- b. During the walkdown, identify any discrepancies. Verify that systems/trains credited as being operable or functional were not rendered inoperable, nonfunctional, or degraded by maintenance. As appropriate, consider items in Section 03.02e.
- c. For the offsite power system, verify the licensee has established and continues to implement periodic walkdown activities to detect visible open phase conditions for switchyard equipment such as insulators, disconnect switches, and transmission line and transformer connections, associated with the offsite power circuits. [C1]
03.02 Complete Walkdown Sample Walkdown and verify that the selected mitigating system is correctly aligned and able to perform its intended safety function(s).
Specific Guidance Mitigating systems should not be constrained to systems covered by the Mitigating Systems Performance Indicator or IMC 0609, Attachment 4, Initial Characterization of Findings.
- a. Review documents to determine the correct system lineup. Consider plant procedures; abnormal and emergency operating procedures; the updated final safety analysis report; vendor technical manuals; piping and instrument drawings; valve, Issue Date: 03/29/21 4 71111.04
switch, and breaker lineups; and plant tagout logs.
- b. Review any outstanding maintenance work requests on the system and any deficiencies that could affect the systems ability to perform its function(s).
- c. Review any outstanding design issues, including temporary modifications, operator workarounds, and items that are tracked by the engineering department.
- d. If appropriate, review available inspection records (e.g., written reports, photographs, or video) associated with normally inaccessible areas that cannot be walked down.
In the past, the licensees may have performed and documented inspections of normally inaccessible areas.
- e. Perform the walkdown inspection. Identify any discrepancies between the existing alignment of the system equipment and the correct alignment. Verify the following:
- 1. Systems, structures, and components (SSCs) do not exhibit defects, such as corrosion, cracks, missing fasteners, and degraded insulation that would impact function.
- 2. When applicable, degraded SSCs have been entered into the licensees corrective action program at the appropriate threshold, and, when applicable, degraded SSCs are being appropriately managed consistent with aging management programs and commitments (e.g., the External Surfaces Monitoring Program, Boric Acid Corrosion Program). Aging management program notebooks and scoping documents developed during the license renewal process are potential inspection resources.
- 3. Valves are correctly positioned and do not show leakage that would impact the function(s) of any given valve.
- 4. Valves are locked as required by the licensees locked valve program.
- 5. Electrical power is available as required. For the offsite power system, verify the licensee has established and continues to implement periodic walkdown activities to detect visible open phase conditions for switchyard equipment such as insulators, disconnect switches, and transmission line and transformer connections, associated with the offsite power circuits. [C1]
- 6. Major system components are correctly lubricated, cooled, and ventilated.
- 7. As-built configuration matches plant documentation. For example, isometric drawings reflect the same nomenclature as found in the actual plant labeling.
- 8. Hangers and supports are correctly installed as designed and are functional.
- 9. Essential support systems are operational.
Issue Date: 03/29/21 5 71111.04
- 10. Ancillary equipment, temporary services, blocked doors, disassembled components, or debris does not interfere with inservice system performance.
- 11. Boundaries or features intended to mitigate initiating events, such as high-energy line breaks, flooding, fire, and security incidents, remain operable or functional as required.
- 12. Tagging clearances or maintenance isolation boundaries do not disable required functions.
- 13. Components subject to harsh environments, including high-energy line breaks, have the appropriate environmental qualification.
- 14. Components potentially vulnerable to threats such as tornado-generated missiles (e.g., steam exhaust piping, emergency diesel generator exhaust piping) are appropriately protected.
71111.04-04 REFERENCES IMC 2515, Appendix A, Risk-Informed Baseline Inspection Program IMC 0308, Attachment 2, Technical Basis for Inspection Program IMC 0609, Attachment 4, Initial Characterization of Findings IP 71111.13, Maintenance Risk Assessments and Emergent Work Control IP 71152, Problem Identification and Resolution Cross Reference of Generic Communications to IP 71111.04 and Inspection Resources: http://drupal.nrc.gov/nrr/ope/33980 (nonpublic)
Operating Experience Gateway: http://drupal.nrc.gov/nrr/ope (nonpublic)
IHS Codes and Standards: http://www.internal.nrc.gov/TICS/library/standards/ihs.html (nonpublic)
U.S. Nuclear Regulatory Commission Technical Library:
http://www.internal.nrc.gov/TICS/library/index.html (nonpublic)
END Issue Date: 03/29/21 6 71111.04
Attachment 1 Revision History for IP 71111.04 Commitment Accession Description of Change Description of Comment Resolution Tracking Number Training and Closed Number Issue Date Required and Feedback Form Change Notice Completion Date Accession Number (Pre-Decisional, Non-Public Information)
N/A ML003729327 711111.01 has been issued to provide the minimum None 04/03/00 inspection oversight for determine the safety CN 00-003 performance of operating nuclear power reactors.
N/A ML020380500 IP 71111.04 has been revised to provide None 01/17/02 clarifications to the inspection requirements CN 02-001 concerning partial walkdowns and identification and resolution of problems. In addition, inspection resource estimates and level of effort are revised to provide a band for more inspection flexibility.
N/A ML070370430 IP 71111.04 has been revised to address feedback None 02/27/07 form 71111.04-721 to clarify the wording in the CN 07-007 Inspection Requirements section to address systems of high risk significance. Revision history reviewed for the last four years.
N/A ML11201A173 The sample size for IP 71111.04 has been revised None 10/28/11 to reflect the 2011 ROP Realignment.
CN 11-025 N/A ML13025A338 Revised to allow the flexibility to perform one of the None ML13060A500 04/24/13 two complete system walkdowns outside of the FF 71111.04-1856 CN 13-012 mitigating systems cornerstone.
Issue Date: 3/29/21 Att1-1 71111.04
Commitment Accession Description of Change Description of Comment Resolution Tracking Number Training and Closed Number Issue Date Required and Feedback Form Change Notice Completion Date Accession Number (Pre-Decisional, Non-Public Information)
N/A ML13338A243 Added additional guidance related to mitigating None ML14233A087 09/24/14 system sample selection, incorporated ROP 71111.04-1935 CN 14-022 Enhancement Initiative Improvements ML14266A021 (ML14017A340 & ML14017A381), incorporated 71111.04-1990 license renewal age management guidance, and ML14266A026 addressed a Fort Calhoun lesson learned 71111.04-2054 recommendation. ML14266A037 N/A ML18047A019 Reformatted inspection procedure. Restored None ML18047A017 12/20/18 requirement to complete two mitigating system 71111.04-2324 CN 18-044 walkdowns. ML18346A566 N/A ML19291A216 Added AP1000 inspection requirements. Added None ML20233A725 10/05/20 reference documents.
CN 20-049 C1 ML21032A255 Revised to incorporate Commission direction in None ML21035A181 SRM-SECY 03/29/21 SRM-SECY-16-0068 to update the ROP to provide 16-0068 CN 21-015 periodic oversight of the industrys Open Phase Condition initiative Issue Date: 3/29/21 Att1-2 71111.04