IR 05000373/2022011
| ML22301A162 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/01/2022 |
| From: | Karla Stoedter NRC/RGN-III/DORS/EB1 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2022011 | |
| Download: ML22301A162 (23) | |
Text
October 31, 2022
SUBJECT:
LASALLE COUNTY STATION - DESIGN BASIS ASSURANCE INSPECTION (TEAMS) INSPECTION REPORT 05000373/2022011 AND 05000374/2022011
Dear David Rhoades:
On October 17, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at LaSalle County Station and discussed the results of this inspection with Phil Hansett, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Two findings of very low safety significance (Green) are documented in this report. Two of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at LaSalle County Station.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; and the NRC Resident Inspector at LaSalle County Station. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Signed by Stoedter, Karla on 10/31/22 Karla K. Stoedter, Chief Engineering Branch 1 Division of Operating Reactor Safety Docket Nos. 05000373 and 05000374 License Nos. NPF-11 and NPF-18
Enclosure:
As stated
Inspection Report
Docket Numbers: 05000373 and 05000374 License Numbers: NPF-11 and NPF-18 Report Numbers: 05000373/2022011 and 05000374/2022011 Enterprise Identifier: I-2022-011-0030 Licensee: Constellation Nuclear Facility: LaSalle County Station Location: Marseilles, IL Inspection Dates: September 19, 2022 to October 07, 2022 Inspectors: K. Fay, Reactor Inspector M. Gangewere, Reactor Inspector S. Kobylarz, Contractor D. Melendez-Colon, Reactor Inspector L. Rodriguez, Senior Reactor Inspector E. Sanchez Santiago, Senior Project Engineer M. Siddiqui, Reactor Inspector Approved By: Karla K. Stoedter, Chief Engineering Branch 1 Division of Operating Reactor Safety Enclosure
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a design basis assurance inspection (teams) inspection at LaSalle County Station, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
Failure to Incorporate Instrument Uncertainty Into Emergency Diesel Generator 7-Day Fuel Supply Surveillance Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.21M Systems NCV 05000373,05000374/2022011-01 Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50,
Appendix B, Criterion XI, "Test Control," when the licensee failed to incorporate the instrument uncertainty calculated in design document Engineering Change 364755, Revision 3 into the acceptance limits of procedure LOS-DG-M2, Revision 109. Additionally, the licensee failed to account for instrument uncertainty when evaluating test results to ensure the diesel fuel oil subsystem contained the 7-day supply of fuel required by technical specification (TS)surveillance requirement (SR) 3.8.3.1.
Failure to Determine Compliance with Technical Specification Surveillance Requirement 3.8.3.1 in Accordance With Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.1] - 71111.21M Systems NCV 05000373,05000374/2022011-02 Resources Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when the licensee failed to determine compliance with TS SR 3.8.3.1 in accordance with procedure LOS-DG-M2, Attachment 2A-IDLE, Step 4.19. Specifically, the licensee incorrectly used the total volume in the fuel oil storage and day tanks, instead of appropriately converting the recorded levels to usable volume, to demonstrate the 7-day supply of fuel oil requirement was met.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
===71111.21M - Design Bases Assurance (DBA) Inspection The inspectors evaluated the following components and listed applicable attributes, permanent modifications, and operating experience:
Design Review - Risk-Significant/Low Design Margin Components (IP Section 02.02)
=
For each component sample, the inspectors reviewed the licensing and design bases including:
- (1) the updated final safety analysis report (UFSAR),
- (2) the TS (where applicable), and
- (3) the technical requirements manual (where applicable). The inspectors also reviewed overall system and component health (including condition reports and operability evaluations, if any). The inspectors performed visual inspections of the accessible components to identify potential hazards or signs of degradation. Additional component specific design attributes reviewed by the inspectors are listed below:
- (1) 2A Diesel Generator (2DG01K)operating procedures (including normal, abnormal, and emergency procedures)maintenance effectiveness (e.g., maintenance rule [MR], procedures)modifications protection against external events o flooding o seismic o high energy line break o fire mechanical design calculations and considerations o fuel oil volume consumption o fuel oil available volume and level o fuel oil transfer design (e.g., flow capacity, net positive suction head)o combustion air supply design o exhaust system design o engine trip set points o room heat up calculations o room cooling test and inspection procedures, acceptance criteria, and recent results o engine o TS surveillances o fuel oil volume and quantity electrical design calculations and considerations o load voltage drop o surveillance tests (load, voltage, frequency)o output breaker control logic o relay coordination o protective relay and meter calibration o protective relay setpoint o capability to start under degraded voltage conditions
- (2) Division III 125VDC Battery (2DC018E)maintenance effectiveness (e.g., MR, procedures)modifications translation of vendor specifications protection against external events and mechanical design o flood protection o seismic o room ventilation test and inspection procedures, acceptance criteria, and recent results o TS surveillance o discharge testing o battery charger electrical design o battery sizing o duty cycle o minimum voltage o battery life o battery charger sizing
- (3) High Pressure Core Spray Pump Minimum Flow Isolation Valve (2E22-F012)operating procedures (including normal, abnormal, and emergency procedures)modifications environmental qualification mechanical design o weak link analysis o pressure locking and thermal binding o closure and opening time o maximum allowed leakage test and inspection procedures, acceptance criteria, and recent results o leakage o in-service testing (IST)o thermal overload bypass testing o preventive maintenance motor power requirements o voltage drop o control logic o required minimum voltage o degraded voltage effects o brake horsepower o motor thermal overload protection o cable ampacity o protective devices o emergency power
- (4) Hardened Containment Vent System Inboard Primary Containment Isolation Valve (2PC009A)operating procedures (including normal, abnormal, and emergency procedures)maintenance effectiveness (e.g., MR, procedures)modifications translation of vendor specifications protection against external seismic event mechanical design calculations and considerations o weak link analysis o required thrust and torque o maximum allowed leakage o maximum differential pressure o air supply sizing (including minimum supply time and pressure)o air supply pressure control setpoint o pneumatic pressure requirements o closure and opening time leak rate testing, acceptance criteria, and recent results electrical design calculations and considerations o control logic o control circuit voltage o control logic protective device o emergency power
Design Review - Large Early Release Frequency (LERFs) (IP Section 02.02) (1 Sample)
- (1) Primary Containment Vacuum Breaker 2A (2PC001A)operating procedures (including normal, abnormal, and emergency procedures)protection against external seismic event mechanical design calculations and considerations o maximum allowed leakage o required pressure for actuation o sizing test and inspection procedures, acceptance criteria, and recent results o functional tests o leakage o IST o position indication
Modification Review - Permanent Mods (IP Section 02.03) (6 Samples)
- (1) Engineering Change (EC) 628849, "ARI & ATWS-RPT Setpoint Change"
- (3) EC 399393, "Replace U1 Leading Edge Flow Meter Electronics"
Review of Operating Experience Issues (IP Section 02.06) (2 Samples)
- (1) Information Notice (IN) 2021-03, Operating Experience Related to the Duane Arnold Energy Center Derecho
- (2) IN 2006-22, "New ULS Diesel Fuel Oil Could Adversely Impact Diesel Engine Performance"
INSPECTION RESULTS
Failure to Incorporate Instrument Uncertainty Into Emergency Diesel Generator 7-Day Fuel Supply Surveillance Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green None (NPP) 71111.21M Systems NCV 05000373,05000374/2022011-01 Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XI, "Test Control," when the licensee failed to incorporate the instrument uncertainty calculated in design document Engineering Change 364755, Revision 3 into the acceptance limits of procedure LOS-DG-M2, Revision 109. Additionally, the licensee failed to account for instrument uncertainty when evaluating test results to ensure the diesel fuel oil subsystem contained the 7-day supply of fuel required by technical specification (TS) surveillance requirement (SR) 3.8.3.1.
Description:
LaSalle Generating Station had a total of five emergency diesel generators (EDGs) as the onsite standby power sources in case offsite power were lost to the site. Each EDG was provided with a fuel storage tank and a day tank. TS 3.8.3, Diesel Fuel Oil and Starting Air, SR 3.8.3.1 required the licensee to maintain greater than or equal to a 7-day supply of fuel in the combined fuel oil storage tank and day tank for each of the EDGs.
For the S15 ultra low sulfur diesel (ULSD) fuel used at the site, the licensee determined 32,200 gallons was the required usable volume of diesel fuel to support continuous EDG operation for 7 days, which was incorporated into the TS 3.8.3 bases.
The inspectors reviewed EDG surveillance test procedure LOS-DG-M2, Revision 109, 1A(2A) Diesel Generator Operability Test, which ensured compliance with SR 3.8.3.1 for the 2A EDG combined fuel oil storage tank and day tank. The inspectors determined the procedure was not consistent with the requirements and acceptance limits established in design calculation L-003416, Revision 0, Emergency Diesel Generators Onsite Usable Fuel Volume Requirements and engineering change (EC) 364755, Revision 3, Impact of ULSD Fuel on the Emergency Diesel Generators and Fuel Oil Storage System. The design calculations determined a bounding pound-mass requirement for the 0, 1A, and 2A EDG (the Division 1 & 2 EDG) storage tanks to support 7 days of operation. This mass requirement was then used to determine a bounding storage tank level. A minimum storage tank level of 18.53 feet was selected to account for the instrument uncertainty (0.35 feet) of the Ashcroft Model 1188 level instrument. EC 364755 concluded If the level in the Division 1 & 2 Storage Tanks 0(1)(2)DO01T are maintained at a minimum indicated level of 18.53 feet there will be enough available fuel volume to support 7 days of EDG operation with ULSD fuel.
Surveillance procedure LOS-DG-M2, Attachment 2A-IDLE, 2A Diesel Generator Idle Start, Step 4.19 established the acceptance criteria for SR 3.8.3.1 as greater than 32,200 usable gallons of fuel in the combined fuel oil storage tank and day tank. The procedure step, among other things, required the fuel storage tank level to be recorded and then converted to usable volume using Figure 1, Diesel Fuel Storage Tank 0DO01T and 1(2)DO01T Level Correlation Table. Note 2 of Figure 1 stated, 18.18 feet (34,413 gallons) meets the TS minimum of 32,200 gallons plus 2,213 unusable gallons. Although EC 364755 attempted to account for the instrument uncertainty of the level indicator by establishing 18.53 feet as the level that corresponded to 32,200 usable gallons of fuel in the tank, procedure LOS-DG-M2 Figure 1 established 18.18 feet as the level which corresponded to 32,200 usable gallons of fuel in the tank. Therefore, procedure LOS-DG-M2 did not account for the 0.35 feet of instrument uncertainty associated with the level indicator. The inspectors reviewed the past three surveillances completed for the 2A EDG and did not find any instances where the test, nor the evaluation of the test results, had accounted for the instrument uncertainty of the tank level indicator. The inspectors determined the impact of the level indicators instrument uncertainty on the available supply of fuel in the storage tank could not be bounded by the margin in design calculations L-003416 and EC 364755.
The inspectors concluded instrument uncertainty had not been accounted for in the surveillance procedure, nor in the evaluation of the test results, to ensure compliance with TS SR 3.8.3.1 for the 2A EDG. The same inconsistency was determined to impact all five EDGs.
Corrective Actions: The licensee entered this issue into their corrective action program and reviewed recent TS surveillance results for all EDGs to verify the fuel volumes recorded met the SR 3.8.3.1 requirements. They did not identify any instances where the levels were below the 7-day requirement. The licensee planned to revise affected procedures to incorporate the EC 364755 conclusions.
Corrective Action References: AR 0459376, NRC ID Question on Diesel Fuel Oil 7-Day Requirement
Performance Assessment:
Performance Deficiency: The licensees failure to account for instrument uncertainty was a performance deficiency and a violation of 10 CFR 50, Appendix B, Criterion XI, 'Test Control."
Specifically, the licensee failed to include the uncertainty calculated in design document EC 364755 into the acceptance limits of procedure LOS-DG-M2, Revision 109. Additionally, the licensee failed to account for instrument uncertainty when evaluating test results to ensure the diesel fuel oil subsystem contained the 7-day supply of fuel.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Procedure Quality attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to account for instrument uncertainty when demonstrating compliance with the 7-day supply of fuel required by TS SR 3.8.3.1 adversely affected the cornerstone objective of ensuring the capability of the EDG to respond to initiating events to prevent undesirable consequences. Similar to example 3.g of IMC 0612 Appendix E, there was reasonable doubt enough fuel was available for the EDG to operate for 7 days when considering the performance deficiency.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the finding was of very low safety significance (Green) because they answered No to all of the questions in Exhibit 2, Mitigating Systems Screening Questions.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. Specifically, EC 364755, Revision 3, which calculated the instrument uncertainty of the level indicators used to determine the quantity of diesel in the fuel tanks, was developed in 2008.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion XI, "Test Control," requires, in part, a test program be established to assure that all testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents. Additionally, it requires test results be documented and evaluated to assure that test requirements have been satisfied.
Contrary to the above, as of October 17, 2022, the licensee failed to assure testing required to demonstrate the diesel fuel oil subsystem would perform satisfactorily in service was identified and performed in accordance with written test procedures which incorporated the requirements and acceptance limits contained in applicable design documents. In addition, the licensee failed to evaluate test results to assure that test requirements had been satisfied.
Specifically, the licensee failed to incorporate the instrument uncertainty calculated in design document EC 364755, Revision 3 into the acceptance limits of procedure LOS-DG-M2, Revision 109. Additionally, the licensee failed to account for instrument uncertainty when evaluating test results to ensure the diesel fuel oil subsystem contained the 7-day supply of fuel required by TS SR 3.8.3.1.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Determine Compliance with Technical Specification Surveillance Requirement 3.8.3.1 in Accordance With Procedure Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.1] - 71111.21M Systems NCV 05000373,05000374/2022011-02 Resources Open/Closed The inspectors identified a finding of very low safety significance (Green) and an associated NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when the licensee failed to determine compliance with TS SR 3.8.3.1 in accordance with procedure LOS-DG-M2, Attachment 2A-IDLE, Step 4.19. Specifically, the licensee incorrectly used the total volume in the fuel oil storage and day tanks, instead of appropriately converting the recorded levels to usable volume, to demonstrate the 7-day supply of fuel oil requirement was met.
Description:
LaSalle Generating Station had a total of five EDGs as the onsite standby power sources in case offsite power were lost to the site. Each EDG was provided with a fuel storage tank and a day tank. TS 3.8.3, Diesel Fuel Oil and Starting Air, required the stored diesel fuel oil and starting air subsystem to be within limits for each required EDG. Specifically, TS SR 3.8.3.1 required the licensee to verify there was greater than or equal to a 7-day supply of fuel in the combined fuel oil storage tank and day tank for each of the EDGs.
Licensee surveillance procedure LOS-DG-M2, Revision 109, 1A(2A) Diesel Generator Operability Test, Attachment 2A-IDLE, 2A Diesel Generator Idle Start," was an implementing procedure used by the licensee to demonstrate compliance with TS SR 3.8.3.1 for the 2A EDG. Step 4.19 of Attachment 2A-IDLE established the acceptance criteria for SR 3.8.3.1 as greater than 32,200 usable gallons of fuel in the combined fuel oil storage tank and day tank. The procedure step required the fuel storage tank level to be recorded and then converted to usable volume using Figure 1, Diesel Fuel Storage Tanks 0DO01T and 1(2) DO01T Level Correlation Table of Procedure LOS-DG-M2. The licensee was expected to find the total volume of fuel in the storage tank for the recorded level and then subtract the unusable volume (2,213 gallons according to Note 1 of LOS-DG-M2 Figure 1) to determine the usable volume of fuel in the storage tank. Similarly, Step 4.19 required the day tank level to be recorded and then converted to usable volume using LOP-DO-02, Transferring Diesel Fuel From Storage Tanks to Day Tanks, Table 1, "(0DO02T), 1(2)DO05T Diesel Fuel Day Tank Level Correlation Table." The licensee was expected to find the total volume of fuel in the day tank for the recorded level and then subtract the unusable volume (35 gallons according to Note 2 of LOP-DO-02 Table 1) to determine the usable volume of fuel in the day tank.
The inspectors reviewed recently completed work orders implementing surveillance test procedure LOS-DG-M2 for the 2A EDG and noted the licensee consistently failed to subtract the unusable fuel volumes when converting recorded levels to usable volumes for the fuel storage tank and day tank. Therefore, the licensee incorrectly used total volume in the tanks, instead of usable volume, to demonstrate compliance with TS SR 3.8.3.1. The same inconsistency was determined to impact all five EDGs. This error could have caused the licensee to incorrectly declare TS SR 3.8.3.1 as being met with less than a 7-day supply of fuel oil being available for the respective EDGs.
Corrective Actions: The licensee entered this issue into their corrective action program and reviewed recent TS surveillance results for all EDGs to verify the fuel volumes recorded were within the 7-day usable fuel supply acceptance criteria. The licensee also planned to update the affected surveillance procedures to make them clearer.
Corrective Action References: AR 04527147, "NRC ID DBAI: Diesel Fuel Oil Level Calculation Errors"
Performance Assessment:
Performance Deficiency: The licensees failure to determine compliance with TS SR 3.8.3.1 in accordance with procedure LOS-DG-M2, Attachment 2A-IDLE, Step 4.19 was a performance deficiency and a violation of 10 CFR 50 Appendix B, Criterion V. Specifically, the licensee incorrectly used the total volume in the fuel oil storage and day tanks, instead of appropriately converting the recorded levels to usable volume, to demonstrate the 7-day supply of fuel oil requirement was met.
Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, the failure to appropriately convert the fuel oil storage and day tank recorded levels to usable volume could have caused the licensee to incorrectly declare TS SR 3.8.3.1 as being met with less than a 7-day supply of fuel oil being available. Similar to example 3.g of IMC 0612 Appendix E, "Examples of Minor Issues," when the non-conservative total volume of fuel in the tanks was used to demonstrate compliance with TS SR 3.8.3.1, there was reasonable doubt enough fuel was available for the EDG to operate for 7 days.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the finding was of very low safety significance (Green) because they answered No to all of the questions in Exhibit 2, Mitigating Systems Screening Questions.
Cross-Cutting Aspect: H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety.
Specifically, procedure LOS-DG-M2, Attachment 2A-IDLE, Step 4.19 required multiple actions which were not separated out to convert the recorded levels to usable volumes, creating an error trap for the procedure users.
Enforcement:
Violation: Title 10 CFR 50 Appendix B, Criterion V, Instructions, Procedures, and Drawings requires, in part, that activities affecting quality be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and be accomplished in accordance with those instructions, procedures, or drawings.
Licensee procedure LOS-DG-M2,1A(2A) Diesel Generator Operability Test, Revision 109, 2A-IDLE, 2A Diesel Generator Idle Start," Step 4.19 demonstrated compliance with TS SR 3.8.3.1 for having greater than or equal to a 7-day supply of fuel oil in the combined fuel oil storage tank and day tank for the 2A EDG. Specifically, Step 4.19 required the following, RECORD 2A Diesel Generator Fuel Storage Tank level and FO Day Tank Level (from Step 4.14.8) and CONVERT to useable volume. (Refer to Figure 1 and LOP-DO-02 Table 1)."
Contrary to the above, from at least September 2021 until October 2022, the licensee failed to accomplish an activity affecting quality in accordance with documented procedures.
Specifically, the licensee failed to determine compliance with TS SR 3.8.3.1 in accordance with procedure LOS-DG-M2, Attachment 2A-IDLE, Step 4.19. The licensee incorrectly used the total volume in the fuel oil storage and day tanks, instead of appropriately converting the recorded levels to usable volume, to demonstrate the 7-day supply of fuel oil requirement was met.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Very Low Safety Significance Issue Resolution Process: Suppression Chamber- 71111.21 to-Drywell Vacuum Breaker Isolation Valves PC002A/B/C/D and PC003A/B/C/D M Scoping in the In-Service Testing Program This issue is a current licensing basis question and inspection effort is being discontinued in accordance with the Very Low Safety Significance Issue Resolution (VLSSIR) process. No further evaluation is required.
Description:
There were four self-actuating vacuum breakers mounted in separate piping between the drywell and the suppression chamber. The vacuum breakers had a safety function to remain closed and to reclose after opening when drywell pressure exceeded suppression chamber pressure during an accident to prevent bypass leakage. Bypassing the pressure suppression pool during an event could have caused containment design pressures to be exceeded. The vacuum breakers also had a safety function to open during an event to relieve pressure from the suppression chamber back to the drywell. A higher pressure in the suppression chamber relative to the drywell would have challenged containment integrity.
Each vacuum breaker assembly contained two manual butterfly isolation valves (PC002A/B/C/D and PC003A/B/C/D), one on each side of the vacuum breaker. These valves could have been used to isolate a failed open vacuum breaker to prevent bypass leakage during an event.
The inspectors noted the manual isolation valves were not within the site's IST program and identified an issue of concern on whether they should have been included in the program and tested accordingly.
The inspectors noted the manual isolation valves were cycled (i.e., full-stroke exercised)during the performance of procedures LTS-500-1, Drywell to Suppression Pool Vacuum Breaker Seat Leakage Test, and LTS-500-2, Drywell Suppression Chamber Vacuum Breaker Valve Force Check. In addition, procedure LTS-100-50, Drywell/Suppression Chamber PC Vacuum Breaker Manual Isolation Valves Outboard Flange Seal Leak Check 1(2)PC002A/B/C/D and 1(2)PC003A/B/C/D leak checked the outboard flanges of the valves by pressurizing each drywell to suppression chamber vacuum breaker line. Therefore, the inspectors concluded testing of the manual isolation valves, although not performed in accordance with the IST program, would provide some assurance the valves could be used to prevent bypass leakage if a vacuum breaker were to fail open during an event.
Licensing Basis: The licensee performed a review of the accident analysis and concluded the manual isolation valves (PC002A/B/C/D and PC003A/B/C/D) were not credited for isolation of the vacuum breaker lines under accident conditions and as such, did not meet the criteria for scoping them into the IST program.
The inspectors reviewed TS 3.6.1.6, Suppression Chamber-to-Drywell Vacuum Breakers, required action C.1, and noted it required both manual isolation valves be closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> if a suppression chamber-to-drywell vacuum breaker was not closed.
The inspectors also reviewed the UFSAR and noted Table 6.2-21, Summary of Lines Penetrating the Primary Containment, listed the vacuum breakers and their associated butterfly valves. Note 4 of the table which applied to these valves stated, in part, If a vacuum breaker valve is inoperable, the butterfly valve will be closed to prevent bypass leakage.
Lastly, the inspectors reviewed operating abnormal procedure LOA-PC-201, Primary/Secondary Containment Trouble, Revision 23, Section B.2, Stuck Open Suppression Pool to Drywell Vacuum Breaker, and noted it stated, If the vacuum breaker can NOT be closed, CLOSE the Primary Containment Vacuum Breakers isolation valves on B. Attachment B listed isolation valves PC002A/B/C/D and PC003A/B/C/D.
As mentioned above, there were statements in the TS, UFSAR, and abnormal operating procedure that directed the licensee to close the manual isolation valves if a vacuum breaker was inoperable and failed to close. That information led the inspectors to believe the valves had a licensing basis mitigating function during an event to prevent bypass leakage which would have required them to be scoped into the IST program. However, as of the conclusion of the inspection, the inspectors were not able to determine whether the issue of concern was a part of the plants current licensing basis. As a result, the inspectors determined this issue should be evaluated using the VLSSIR process since the resources required to resolve the current licensing basis question would not effectively and efficiently serve the agencys mission.
Significance: For the purpose of the VLSSIR process, the inspectors screened the issue of concern through IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the issue of concern would likely be of very low safety significance (Green) had a performance deficiency been identified because they answered No to all of the questions in Exhibit 3, Barrier Integrity Screening Questions, Section C, Reactor Containment.
Corrective Action Reference: AR 04526854, NRC ID: 1(2)PC002A-D and 1(2)PC003A-D Not In IST Program.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On October 17, 2022, the inspectors presented the design basis assurance inspection (teams) inspection results to Phil Hansett, Site Vice President, and other members of the licensee staff.
On October 7, 2022, the inspectors presented the interim design basis assurance inspection (team) inspection results to Phil Hansett, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection Type Designation Description or Title Revision or
Procedure Date
71111.21M Calculations 004-E-019-E22 LaSalle 2 - MOV Terminal Voltage Calculations - System 2A
E22
3C7-0277-003 Vacuum Breaker Sizing 8
AN-01 Diesel Generator Relay Settings 2A
DG-4 Diesel-Generator Intake Pressure Losses 0
DO-9 Diesel Fuel Transfer Pump NPSH 1
EMD-026641 Valve Qualification Covered by Report LA-241-026 0
L-000978 Reactor Vessel Water Level 2 Alternate Rod Insertion (ARI) 1
and Anticipated Transient Without SCRAM Recirculation
Pump Trip (ATWS - RPT) Setpoint Error Analysis
L-000979 Reactor High Pressure Alternate Rod Insertion (ARI) & 1
Anticipated Transient Without Scram Recirculation Pump
Trip (ATWS-RPT) Setpoint Error Analysis
L-001221 HPCS Pump Cubicle Cooler Ventilation System 2
L-001893 Loop Accuracy for the CSCS Area Coolers SE and SW 0B
Cooling Water Discharge Flow
L-002276 Calculation of the HPCS, LPCS and LPCI Minimum 0A
Required Pump Head to Meet the LOCA Analysis
Assumptions
L-002404 CSCS Cooling Water System "Road Map" Calculation 5
L-002901 Verification of the Division 1 and 2 Diesel Oil Storage and 1A
Day Tank Volumes
L-003288 Drywell to Suppression Pool Vacuum Breaker Seat Leakage 0
Allowable Values
L-003364 Auxiliary Power Analysis 4
L-003416 Emergency Diesel Generators Onsite Usable Fuel Volume 0
Requirements
L-003418 Emergency Diesel Generator Fuel Oil Setpoints 0
L-003447 125VDC System Analysis 3
L-004114 125VDC Battery Sizing Calculation for Hardened 0
Containment Vent System for 24 Hour Duty Cycle
L-004134 Structural Qualification of the HCVS ROS Instrument Rack 0
Inspection Type Designation Description or Title Revision or
Procedure Date
L-004143 Seismic Qualification of Various Components for the 0
Hardened Containment Vent System Modifications
L-004182 2PC009A HCVS PCIV Torque 0
Requirements 330-10001434-50
L-004282 VY02A Cooler Thermal Performance Model 1
LAS-2E22-F012 Rising Stem Motor Operated Valve Data Sheet 11
S30 HPCS Switchgear Room Flooding due to Postulated Crack 0
in 36" CW Manway
VD-1A Standby Diesel Gen. Room Ventilation System 1A
VD-1B Diesel Fuel St Tank RM & Diesel Oil Day Tank Room 1A
Ventilation System
Calibration 04583739-01 DG-2A Relay and Meter Calibrations 12/15/2020
Records
Corrective Action 00534749 Assignments 11, 22, 32, 38, 68 10/20/2006
Documents 01480079 2PC001A Outboard Flange Seal LLRT Above Warning Limit 02/26/2013
L2R14
2735689 Unit 2 Div 3 125V Battery Cell 54 had Low Cell Voltage 11/01/2016
03997641 Work Request for Gate Valve - Part 21 04/13/2017
04025405 Extent of Condition Testing for ADDDGVS 06/25/2017
04040286 HCVS Argon Bottle Pressure Low 08/09/2017
04041440 HCVS Argon Bottle Pressure Still Low with New Bottles 08/12/2017
04046514 2E22-F012 Baseline Reference Stem Rotation Value 08/28/2017
Established
04049170 U2 HCVS Argon Pressure Low 09/05/2017
04138026 U2 HCVS Argon Bottles Recharged 05/15/2018
04147397 U2 HCVS Argon Pressure Low 06/15/2018
04151839 Trend IR: Small Argon Leak on U2 HCVS Bottle Banks 06/29/2018
205948 Spurious U-2 DG Penthouse Fire Alarm During 2B Run 12/27/2018
215364 U2 Div 3 Battery Charger Amp Indication Hard Downscale 01/30/2019
223295 2E22-F012 Legacy Casting Defect 02/25/2019
04324097 U1 LEFM Panel Message Minor Alarm from Source PLC2 03/05/2020
04332774 U1 LEFM Panel Message Minor Alarm from Source PLC2 04/04/2020
04341060 U1 LEFM Panel Shows Alarm 05/05/2020
Inspection Type Designation Description or Title Revision or
Procedure Date
04357317 Unexpected MCR Alarm, U2 DG Penthouse Fire Alarm 07/17/2020
04368958 U1 Fire Alarm - DG Penthouse Zone 1-29 09/12/2020
04391905 U2 Div 3 Battery Vents Broken 12/23/2020
04398104 2DC18E Div 3 125VDC Battery, with Broken Hydrogen 01/26/2021
Diffusers
04409079 DG Penthouse Fire Alarm During DG Run 03/15/2021
04423475 Ground Strap Near U-2 HPCS Min Flow Vlv Disconnected 05/13/2021
04424053 Multiple Fire Alarms Received During 2A DG Run 05/17/2021
04431472 Unexpected MCR Alarm 1PM10J-B303 Window 601 06/25/2021
04431877 Unexpected MCR Fire Alarm, FZ 2-29 06/28/2021
04434463 Unexpected MCR Alarm on F/Z 2-29 Detector OXY-2-29-7 07/11/2021
Failed
04437000 End Ldrs Not Holding mgrs/engs Accountable to Follow 07/26/2021
Procs
04456704 Fire Alarm Unit 1 DG Penthouse - 1B DG 10/28/2021
04465253 Unit 2, Div 3 Battery Cell 2 Cell Voltage Trend 12/07/2021
04513463 2DC18E Cell #2 Voltage Low 07/28/2022
04517999 U2 LEFM Panel Shows a Yellow Wrench with Alarm 05/04/2022
Message- Minor
04519674 PCR for LOS-DC-Q2 Att B 08/30/2022
Corrective Action 04523547 NRC ID DBAI - Design Analysis 026641 (EMD) Discrepancy 09/20/2022
Documents 04523754 NRC ID'd Small Leak on U2 RHR SVC WTR 09/21/2022
Resulting from Strainer 2E12-D300B
Inspection 04524086 NRC ID'd DBAI - U2 HCVS Nitrogen and Argon Header 09/22/2022
Leakage
04524109 NRC ID Padlocks Installed on 2PC431/520/516 09/22/2022
04524813 White Rectangular Blocks Observed Behind 2VD02YA/B 09/27/2022
04525406 NRC ID Debris Found on Floor Behind 2VD10YA(B) 09/29/2022
04525625 NRC ID DBAI 1(2)PC001A/B/C/D Size Discrepancy 09/29/2022
04526798 NRC Identified: 111X Door Latch no Longer Works 10/04/2022
04526854 NRC ID: 1(2)PC002A-D and 1(2)PC003A-D Not in IST 10/04/2022
Program
Inspection Type Designation Description or Title Revision or
Procedure Date
04527059 NRC ID DBAI: UFSAR Incorrect Statement 10/05/2022
04527084 NRC ID DBAI: PCRA LOP-PC-04E 10/05/2022
04527147 NRC ID DBAI: Diesel Fuel Oil Level Calculation Errors 10/05/2022
04527365 Unit 2 Div 3 Flame Arrestors 10/06/2022
04527593 NRC Observation, Potential Enhancement to LOS-DC-Q2 10/07/2022
04527597 NRC Observation on Engineering Walkdowns 10/07/2022
04529376 NRC ID Question on Diesel Fuel Oil 7-Day Requirement 10/14/2022
Drawings 1E-0-4000FA Key Diagram Hardened Containment Vent System (HCVS) A
25VDC Distribution Panel 0DC52E
1E-2-4000DA Key Diagram 480V AC MCC 243-1 (2AP79E) U
1E-2-4000FD 125V DC Distribution Ess. Div 3 N
1E-2-4009AA Schematic Diagram 4160V Switchgear 242(Y) (2AP06E) Y
Diesel Generator 2A Feed ACB 2423 System DG Part 1
1E-2-4081ZF Schematic Diagram Valve 2PC009A Hardened Containment A
Vent System (HCVS) Part 1
1E-2-4081ZG Schematic Diagram Valve 2PC009A Hardened Containment A
Vent System (HCVS) Part 2
1E-2-4222AE Schematic Diagram High Pressure Core Spray System HP N
(E22A) Part 5
1E-2-4223AS HPCS 125V DC Battery Charger 2C G
LF240-369 In-Line Vacuum Breaker 24" Wafer Design D
M-132 P&ID Diesel Oil System AC
M-138 Sht. 3 P&ID Primary Containment Vent and Purge B
M-141 P&1D High Pressure Core Spray (HPCS) AS
M-1438 High Pressure Core Spray Switchgear Room and High J
Radiation Sampling Ventilation System Elevation 687'-0"
M-1446 P&ID HPCS Diesel Generator Room, Switchgear Room & L
Pump Room Ventilation Systems
M-1447 P&ID Diesel Generator Room Ventilation System J
M-1538 Sht. 105 Ventilation Duct Seismic Hanger Details E
M-1538 Sht. 107 Ventilation Duct Seismic Hanger Details D
M-2057 P&I/C&I Details Geedwater System-FW B
M-3447 Sht. 1 HVAC C&I Details Diesel Generator Vent System Supply E
Inspection Type Designation Description or Title Revision or
Procedure Date
Fan Start/Stop and Damper Interlock TIC Detail-A
Engineering 056706 2E22-F012 Drill Hole in Upstream Disc to Prevent Press 1
Changes Lock
265044 CGD - Fuel Diesel Grade No. 1 Ultra Low Sulfur - 0
Equivalence
364755 Impact of ULSD Fuel on the Emergency Diesel Generators 3
and Fuel Oil Storage System
396444 Emergency Diesel Generator 0, 1A, 2A Div. 1 & 2 Speed 0
Switch Upgrade
396561 Stagger Low Feedwater Pump Suction Pressure Trips (U2) 0
399393 Replace U1 Leading Edge Flowmeter (LEFM) Electronics 1
2652 1VY02A Replacement - HPCS Area Cooler 0, 1, and 2
28849 EOC - ARI & ATWS-RPT Setpoint Change 0
Miscellaneous C&D 125VDC Standby Battery Vented Cell Installation & Operating 0
Battery Vendor Instructions
Manual
Doc Number 00096111-02 TS, (1130), LOS-DO-SR2 ATT B Rec/Verify 06/23/2022
0009611102 New Diesel Fuel Analysis
IB1606 LEFM Check Plus M3P User Manual 3
Lab No. LOAMS Sample Analysis Report 11/11/2021
2111090207
Lab Number 0054 Cab 261 Truck Sample Diesel Fuel 06/20/2022
Lab Number 0505 Cab 29 Truck Sample Diesel Fuel 10/19/2021
NES-EIC-20.04 Analysis of Instrument Channel Setpoint Error and 6
Instrument Loop Accuracy
Operations Logs Operations Logs for 03/07/2020 03/07/2020
Rosemount Model 1153 Series B Alphaline Pressure Transmitters for E
Instruction Nuclear Services
Manual 4302
Operability 17-002 Extent of Condition Review Performed for the Failure of Unit 0
Evaluations 2 HPCS Injection Valve 2E22-F004
Procedures ER-AA-2030 Conduct of Equipment Reliability Manual 27
LA-PBD-AMP- Program Basis Document LA-PBD-AMP-XI.M30 Fuel Oil 2
XI.M30 Chemistry
Inspection Type Designation Description or Title Revision or
Procedure Date
LGA-VQ-202 Unit 2 Emergency Containment Vent 8
LMS-FP-22 Fire Damper Visual Inspection 16
LOA-FLD-001 Flooding 23
LOA-PC-201 Primary/Secondary Containment Trouble 23
LOP-DG-01 Preparation for Standby Operation of Diesel Generators 41
LOP-DO-01 Receiving and Sampling New Diesel Fuel Oil 42
LOP-DO-02 Transferring Diesel Fuel Oil from Storage Tanks to Day 18
Tanks
LOP-PC-08 Standby Operation of Hardened Containment Vent System 4
(HCVS)
LOR-1H13-P602- Div I Reactor Recirculation Pumps Trip-Anticipated 5
A302 Transient Without Scram Initiated
LOR-1H13-P603- Div I Alternate Rod Insertion Logic Initiated 5
A312
LOS-DC-M5 Monthly Surveillance for Safety Related 250VDC and 16
25VDC Batteries
LOS-DC-Q2 Battery Readings for Safety-Related 250VDC and Div 1,2,3 39
25VDC Batteries
LOS-DG-M2 1A(2A) Diesel Generator Operability Test 109
LOS-DO-SR2 Diesel Fuel Oil Analysis Verification (New Fuel Oil) 20
LOS-PC-SA1 HCVS Bottle Bank Pressure Checks 0
LOS-VY-SR1 ECCS Cubicle Area Cooler Air Flowrate Test 21
LTS-100-50 Drywell/Suppression Chamber PC Vacuum Breaker Manual 13
Isolation Valves Outboard Flange Seal Leak Check
1(2)PC002A/B/C/D and 1(2)PC003A/B/C/D
PES-P-006 Diesel Fuel Oil 13
SEAG 18-000094 Prerequisite of Commissioning Procedure for LEFM 0
Appendix J
Work Orders 00857520 Unit 2 DG 2A Fuel Oil Day Tank Level 06/16/2009
01399105 Unit 2 DG 2A Fuel Oil Day Tank Level 06/11/2014
01526387 Check Grease in Valve Operator Gearbox 04/01/2014
01550419 LLRT, 2PC002A OTBD Flange Seal 02/16/2015
01550420 LLRT, 2PC003A OTBD Flange Seal 02/16/2015
Inspection Type Designation Description or Title Revision or
Procedure Date
01716166 Perform EQ Inspection and Votes Test 2E22-F012 02/05/2015
01810246-01 Integrated Division II ECCS Response Time 03/03/2019
01887924-01 Unit 2 DG 2A Fuel Oil Day Tank Level 12/20/2018
01929364 LLRT, 2PC002A Packing 02/13/2019
01929365 LLRT, 2PC003A Packing 02/13/2019
01951579-01 EWP-EM Perform Breaker Insp 2AP79E-3B Feed to 06/22/2020
04580458 Check Grease in Valve Operator Gearbox 09/26/2019
04602781-01 Performance of LES-DC-708 Rev 7 02/19/2019
04607835-01 2A DG Start and Load Acceptance 03/02/2019
04611076 Perform EQ Inspection and VOTES Test 2E22-F012 02/28/2019
04627475 Work Request for Gate Valve - Part 21 03/01/2019
04660634 Stem Rotation Check on 2E22-F012 08/28/2017
04677534-23 OP PMT - Division 3 Cooling Wtr. Test Per LOS-DG-SR7 06/19/2019
04749053 IST Comprehensive Pump Test for 2E22-C001 11/27/2019
04767004 LOS-HP-Q2 U2 HPCS Valves Att 2A 03/26/2019
04826840 U2 LEFM Obsolescence Panel Upgrade (Online) 12/28/2018
04826844 U1 LEFM Obsolescence Panel Upgrade 01/07/2020
04836772 Diesel Generator "2A" 24-Hour Run Surveillance 11/11/2020
04872997 Perform 2A Diesel Generator Inspection per LMS-DG-01 10/09/2020
04881186 HCVS Walk Down Inspection 10/19/2020
04895519-01 EP LTS-500-2 2PC001A DW to Supp Chamber Vac Bkr 03/01/2021
Force Check
04895520-01 EP LTS-500-1 2PC001A DW to Supp Pool Vac Bkr Seat 03/01/2021
Leakage TS
04895944 U-2 DW to Supp Pool Vac Bkr Seat Leakage Test 2PC001D 03/03/2021
04897147-01 U-2 HPCS System Relay Logic Test & O/L Bypass Test 03/01/2021
04902078 HCVS 2PC009A and 2PC010A LLRT 01/09/2021
04902079 HCVS PCIV Operability and Inservice Inspection 02/28/2021
04904308 LOS-HP-Q2 U2 HPCS Valves Att 2A 11/24/2020
04956433 LOS-HP-Q1 U2 HPCS Att 2A 11/27/2019
05110378 LOS-HP-Q1 U2 HPCS Att 2A 03/18/2021
05195785 LOS-DG-Q2 Att B1, 2A DG Fuel Oil Transfer Pump Test 01/10/2022
Inspection Type Designation Description or Title Revision or
Procedure Date
205732 LRA LOS-DG-Q2 2A D/G Fuel Oil QTR Sample Att B2 02/07/2022
215735-01 EWP MM 2A DG Room Vent Supply Prefilter Replacement 06/10/2022
219128 HCVS Bottle Bank Pressure Verification 01/28/2022
222416 LOS-DG-Q2 Att B1, 2A DG Fuel Oil Transfer Pump Test 04/12/2022
228545 HCVS Bottle Bank Pressure Verification 07/28/2022
228566-01 LOS-DC-W1-D3 02/15/2022
231677 LRA LOS-DG-Q2 2A D/G Fuel Oil QTR Sample Att B2 05/11/2022
240743 (LR) 2DO05T Diesel Fuel Oil Sample Analysis 06/12/2022
241360 LOS-PC-Q3 U2 D/W to S/P Vacuum Brks Att 2A 05/27/2022
250812 LOS-DG-Q2 Att B1, 2A DG Fuel Oil Transfer Pump Test 07/11/2022
251859-01 Performance of LOS-DC-M5-DC 05/24/2022
260073 LRA LOS-DG-Q2 2A D/G Fuel Oil QTR Sample Att B2 08/11/2022
264373-01 Performance of LOS-DC-Q2 Att B 08/30/2022
268769 LRA LOS-DG-M2 2A Diesel Generator Att 2A-Idle 07/06/2022
269444 LRA LOS-DO-M1 Att 2A Verify and Record Fuel Analysis 07/11/2022
Data
269707-01 Performance of LOS-DC-Q2 Att B 09/14/2022
276097 LRA LOS-DG-M2 2A Diesel Generator Att 2A-Idle 08/11/2022
277204 LRA LOS-DO-M1 Att 2A Verify and Record Fuel Analysis 08/16/2022
Data
285519 LRA LOS-DG-M2 2A Diesel Generator Att 2A-Idle 09/08/2022
20