ML23121A148
ML23121A148 | |
Person / Time | |
---|---|
Issue date: | 09/19/2023 |
From: | Aron Lewin NRC/NRR/DRO/IRIB |
To: | |
References | |
DC 23-008, CN 23-028 | |
Download: ML23121A148 (1) | |
Text
NRC INSPECTION MANUAL IRIB INSPECTION PROCEDURE 71111 ATTACHMENT 04 EQUIPMENT ALIGNMENT Effective Date: January 1, 2024 PROGRAM APPLICABILITY: IMC 2515 A CORNERSTONES: Initiating Events Mitigating Systems Barrier Integrity INSPECTION BASES: See IMC 0308, Attachment 2 SAMPLE REQUIREMENTS:
Minimum Baseline Sample Requirements Completion Sample Budgeted Range*
Requirements Sample Type Section(s) Frequency Sample Size Samples Hours 10 to 14 per 10 per site site 52 to 68 per Partial Walkdown 03.01 Annual site 2 to 4 at 2 at Vogtle Vogtle Units 3 & 4 20 to 28 at Units 3 & 4 Vogtle Units 3&4 Complete Walkdown 03.02 Annual 1 per site 1 per site
- 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 />. The 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 />.
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.
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.
Issue Date: 09/19/23 1 71111.04
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 Operating - Equipment lineups affecting Maintenance which leaves only one operating initiating event frequencies or functional feed pump providing feed capabilities of plant equipment Instrument air lineup Shutdown - Equipment 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 Operating - Equipment 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 Shutdown - Equipment 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 Issue Date: 09/19/23 2 71111.04
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 Operating - Fuel 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)
Shutdown - Equipment 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:
- a. risk-informed insights from site-specific risk studies
- b. operator actions and access during potential accident sequences
- c. operating experience
- d. performance history
- e. equipment configuration (e.g., out of service, inoperable, or degraded)
- f. past walkdown samples
- g. recently realigned equipment following an outage, maintenance, modification, or testing
- h. 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) should be inspected consistent with how other non-safety-related SSCs are inspected in currently operating plants. In currently operating plants, inspectors can select inspection activities involving non-safety-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 updated program guidance to clarify that RTNSS SSCs should be treated as any other non-safety-related SSCs. Consistent with risk-informed principles, inspectors are expected not to routinely focus inspection resources on RTNSS SSCs and other non-safety-related systems but rather examine these non-safety-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 Issue Date: 09/19/23 3 71111.04
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 Partially walkdown and verify that the portions of a selected system/train are correctly aligned.
Specific Guidance
- a. Inspectors have flexibility in determining the portions of the selected system/train to be sampled.
- b. Consider review of 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.
- c. For any discrepancies identified during the partial walkdown, verify whether systems/trains credited as being operable or functional were not rendered inoperable, nonfunctional, or degraded.
- d. As appropriate, consider items in section 03.02f.
03.02 Complete Walkdown Sample Completely walkdown accessible areas and verify that the selected system is correctly aligned and able to perform its intended safety function(s).
Specific Guidance
- a. Consider review of 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, switch, and breaker lineups; and plant tagout logs.
- b. Consider review of any outstanding maintenance work requests on the system and any deficiencies that could affect the systems ability to perform its function(s).
- c. Consider review of any outstanding design issues, including temporary modifications, operator workarounds, and items that are tracked by the engineering department.
- d. For the selected system, inspectors should walk down all normally accessible areas. For planning purposes, inspectors should coordinate with the licensee to allow for walkdowns of normally inaccessible areas should they become accessible. However, the inspection schedule is not required to be developed solely based on the availability of normally inaccessible areas. In addition, it is not the intent to force licensees to make a normally inaccessible area of the plant accessible or to place inspectors in harms way Issue Date: 09/19/23 4 71111.04
unnecessarily during performance of this inspection sample. Consider review of 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. IMC 2515, Appendix D, Plant Status, contains additional guidance on normally inaccessible areas.
- e. For any discrepancies identified during the complete walkdown, verify whether systems/trains credited as being operable or functional were not rendered inoperable, nonfunctional, or degraded.
- f. Consider 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, including degraded insulation which potentially can result in corrosion under insulation, 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.
- 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.
Issue Date: 09/19/23 5 71111.04
- 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 0308, Attachment 2, Technical Basis for Inspection Program IMC 2515, Appendix A, Risk-Informed Baseline Inspection Program IMC 2515, Appendix D, Plant Status IP 71111.13, Maintenance Risk Assessments and Emergent Work Control IP 71152, Problem Identification and Resolution END Issue Date: 09/19/23 6 71111.04
Attachment 1: Revision History for IP 71111.04 Commitment Accession Description of Change Description of Comment Resolution Tracking Number Issue Training Required and Closed Feedback Number Date and Completion Form Accession Change Notice Date 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 to None 10/28/11 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: 09/19/23 Att1-1 71111.04
Commitment Accession Description of Change Description of Comment Resolution Tracking Number Issue Training Required and Closed Feedback Number Date and Completion Form Accession Change Notice Date 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 N/A ML22123A169 Samples revised per NRR direction using None N/A Issued as final.
08/01/22 Enclosure 2 (ML19070A040) of SECY-19-0067 CN 22-015 (ML19070A050) as guidance.
N/A ML23121A148 Revised to 1) address OIG Case Number 20-025 as None ML23173A142 09/19/23 discussed in Enclosure 1 of the NRC staffs response CN 23-028 (ML22108A161), and 2) clarify requirements vs guidance per OIG-16-A-12 (ML16097A515).
Issue Date: 09/19/23 Att1-2 71111.04