IR 05000458/2022002
| ML22210A072 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/09/2022 |
| From: | Harry Freeman NRC/RGN-IV/DORS |
| To: | Karenina Scott Entergy Operations |
| Freeman H | |
| References | |
| IR 2022002 | |
| Download: ML22210A072 (23) | |
Text
August 9, 2022
SUBJECT:
RIVER BEND STATION - INTEGRATED INSPECTION REPORT 05000458/2022002
Dear Mr. Scott:
On June 30, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at River Bend Station. On July 7, 2022, the NRC inspectors discussed the results of this inspection with Mr. Robert Walpole, Director, Regulatory Assurance and Performance Improvement, and other members of your staff. The results of this inspection are documented in the enclosed report.
Five findings of very low safety significance (Green) are documented in this report. All 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 IV; the Director, Office of Enforcement; and the NRC Resident Inspector at River Bend 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 IV; and the NRC Resident Inspector at River Bend 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, Jeffrey E. Josey, Chief Projects Branch C Division of Operating Reactor Safety Docket No. 05000458 License No. NPF-47
Enclosure:
Inspection Report 05000458/2022002
Inspection Report
Docket Number:
05000458
License Number:
Report Number:
Enterprise Identifier:
I-2022-002-0011
Licensee:
Entergy Operations, Inc.
Facility:
River Bend Station
Location:
St. Francisville, Louisiana
Inspection Dates:
April 1, 2022, to June 30, 2022
Inspectors:
R. Kumana, Senior Resident Inspector
D. Nani, Project Engineer
C. Wynar, Resident Inspector
Approved By:
Jeffrey E. Josey, Chief
Projects Branch C
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at River Bend 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 Maintain Design Control for External Flood Protection of the Shield Building Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-01 Open/Closed None (NPP)71111.01 The inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, appendix B, criterion III, Design Control, for failure to ensure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to ensure that the shield building equipment hatch, a safety-related structure, was suitably designed to withstand the effects of natural phenomena in accordance with 10 CFR Part 50, appendix A, criterion 2.
The licensee failed to ensure that the equipment hatch maintained its watertight integrity as specified by the updated safety analysis report.
Failure to Maintain a Continuous Fire Watch when Required Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-02 Open/Closed
[H.8] -
Procedure Adherence 71111.05 The inspectors identified a Green finding and associated non-cited violation of River Bend Station, Unit 1, Renewed Facility Operating License, section C(10), for failure to implement the fire protection program by not maintaining a continuous fire watch when required.
Specifically, during a period when a continuous fire watch was required to compensate for an inoperable detection and suppression system, the licensee failed to ensure a required fire watch was always present.
Failure to Demonstrate Effective Control of Performance of a Maintenance Rule (a)(2) System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-03 Open/Closed None (NPP)71111.12 The inspectors identified a Green finding and associated non-cited violation of 10 CFR 50.65(a)(2) for failure to demonstrate the effective control of performance of a maintenance rule scoped system through appropriate preventive maintenance. Specifically, the licensee failed to adequately monitor performance of the standby cooling tower, a maintenance rule scoped structure, in accordance with their preventive maintenance program and also did not implement (a)(1) goals and corrective actions.
Failure to Conduct Adequate Operability Determinations Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-04 Open/Closed
[H.12] - Avoid Complacency 71111.15 The inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, appendix B, criterion V, Instructions, Procedures, and Drawings, with two examples, for failure to follow Procedure EN-OP-104, Operability Determination Process, revision 17, a quality related procedure. Specifically, the licensee failed to perform a detailed operability evaluation when required for a degraded condition on the reactor core isolation cooling pressure transmitter and for non-conforming door seals on the roof of the standby cooling tower.
Failure to Follow Breaker Maintenance Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000458/2022002-05 Open/Closed
[H.5] - Work Management 71153 A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a was identified when the licensee failed to implement written procedures covering activities recommended in Regulatory Guide 1.33, revision 2, appendix A.
Specifically, the licensee failed to follow procedures for reinstalling circuit breakers into switchgear, which resulted in the inoperability of safety-related equipment for longer than the allowed outage time.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000458/2021-003-00 Condition Prohibited by Technical Specifications due to Failure to Perform Breaker Functional Test 71153 Closed
PLANT STATUS
River Bend Station began the inspection period at rated thermal power. On May 15, 2022, power was reduced to approximately 61 percent for a rod pattern adjustment. The plant returned to rated thermal power on May 16, 2022, and remained at or near rated thermal power for the remainder of the inspection period.
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 performed activities described in IMC 2515, appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. 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
71111.01 - Adverse Weather Protection
External Flooding Sample (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated that flood protection barriers, mitigation plans, procedures, and equipment are consistent with the licensees design requirements and risk analysis assumptions for coping with external flooding on May 13, 2022.
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
(1)suppression pool cleanup on May 13, 2022 (2)division II emergency diesel generator on May 17, 2022 (3)primary containment isolation valves on June 16, 2022 (4)residual heat removal C on June 16, 2022 (5)division III emergency diesel generator on June 28, 2022
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
(1)high pressure core spray battery room/battery charger room, fire area C-21, on April 12, 2022 (2)cable chase IV, fire area C-10, on April 21, 2022 (3)cable room B, fire area C-6, on June 1, 2022 (4)standby gas treatment system filter A room, fire area AB-14, on June 15, 2022 (5)division III emergency diesel generator room, fire area DG-5/Z-1, on June 24, 2022
71111.06 - Flood Protection Measures
Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)
The inspectors evaluated internal flooding mitigation protections in the:
- (1) standby service water cooling tower
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) control building chiller C heat exchanger
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during downpower for rod pattern adjustment on May 15, 2022.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated as found operator evaluation in the simulator on May 10, 2022.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
(1)division III battery charger test failure on April 6, 2022 (2)division I emergency diesel generator failure on May 10, 2022 (3)shutdown cooling valve MOV-F063B maintenance preventable functional failure on June 17, 2022
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
(1)elevated risk during reactor core isolation cooling relay testing on April 4, 2022 (2)elevated risk during SWPA11-63XA relay work on April 8, 2022 (3)elevated risk during standby service water cooling tower work on May 5, 2022 (4)elevated risk during high pressure core spray outage on June 23, 2022
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (3 Samples)
The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:
(1)secondary containment equipment hatch on April 25, 2022 (CR-RBS-2022-00975)
(2)standby service water doors on May 18, 2022 (CR-RBS-2022-02367)
(3)reactor core isolation cooling steam flow equipment qualification on May 27, 2022 (CR-RBS-2022-02614)
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)
The inspectors evaluated the following temporary or permanent modifications:
(1)reactor recirculation pump single point vulnerability elimination (EC-88904)
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (6 Samples)
The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:
- (1) Work Order (WO) 52899433-01, division III battery charger, on April 6, 2022
- (2) WO 52955601, residual heat removal B pump sightglass oil leak, on April 13, 2022
- (3) WO 52989906, standby service water SWP-MOV96B repair, on April 29, 2022
- (4) WO 52962619, WO 00572206, WO 00422912, and WO 00543490, division II emergency diesel generator outage, on May 16, 2022
- (5) WO 00577612, instrument air system IAS-C6 battery replacement, on June 1, 2022
- (6) WO 00580444, division II nuclear steam supply system card replacement, on June 16, 2022
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance testing activities to verify system operability and/or functionality:
Surveillance Tests (other) (IP Section 03.01) (2 Samples)
- (1) STP-203-1302, revision 30, E220S001 Battery Quarterly Surveillance, on May 10, 2022
- (2) STP-051-4223, revision 27, ECCS RCIC Reactor Vessel Water Level Low Low Level 2 Channel Calibration, on May 20, 2022
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) STP-256-6302, revision 29, Div II Standby Service Water Quarterly Valve Operability Test, on June 27, 2022
RCS Leakage Detection Testing (IP Section 03.01) (1 Sample)
- (1) STP-000-0001, revision 93, Daily Operating Logs, on May 1, 2022
FLEX Testing (IP Section 03.02) (1 Sample)
- (1) WO 52973294, FLEX Standby PM - 1 Year Operational Test of HCS-ENG1, on May 31, 2022
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)
(1)emergency response drill on April 27,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS06: Emergency AC Power Systems (IP Section 02.05)===
- (1) April 1, 2021, through March 31, 2022
MS07: High Pressure Injection Systems (IP Section 02.06) (1 Sample)
- (1) April 1, 2021, through March 31, 2022
MS08: Heat Removal Systems (IP Section 02.07) (1 Sample)
- (1) April 1, 2021, through March 31, 2022
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)
- (1) The inspectors reviewed the licensees corrective action program for potential adverse trends in staffing issues that might be indicative of a more significant safety issue.
71153 - Follow Up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors evaluated the following licensee event reports (LERs):
- (1) LER 05000458/2021-003-00, Condition Prohibited by Technical Specifications due to failure to perform Breaker Functional Test (ADAMS Accession No. ML21175A038)
The inspection conclusions associated with this LER and an associated non-cited violation are documented in this report under the Inspection Results section.
INSPECTION RESULTS
Failure to Maintain Design Control for External Flood Protection of the Shield Building Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-01 Open/Closed None (NPP)71111.01 The inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, appendix B, criterion III, Design Control, for failure to ensure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to ensure that the shield building equipment hatch, a safety-related structure, was suitably designed to withstand the effects of natural phenomena in accordance with 10 CFR Part 50, appendix A, criterion 2. The licensee failed to ensure that the equipment hatch maintained its watertight integrity as specified by the updated safety analysis report.
Description:
During a walkdown of the exterior of the shield building, the inspectors heard an inrush of air around the shield building equipment hatch. Upon further inspection the inspectors detected airflow along the bottom edge of the door seal and around the gaskets of the door handle. The shield building annulus is kept at a vacuum. The airflow could be heard and felt along the length of the door. Table 3.4-1 in the licensee updated safety analysis report (USAR) states this hatch is subject to flood potential and it is below the design basis flood (DBFL) level. The USAR also calls out in section 3.4.1.1.3 that this seismic category 1 structure meets the intent of 10 CFR 50, appendix A, criterion 2 as a means of providing flood protection by preventing water intrusion into the shield building. The inspectors questioned the ability of the door to function as a watertight barrier due to the airflow around the lower edge. The inspectors determined that the lower edge of the shield building door is at approximately 93-foot elevation and below the DBFL level of 96 feet.
The inspectors determined that the DBFL would result in water entry into the reactor shield building, a safety related structure that was not designed for external flooding. The licensee performed an evaluation to determine the effect on safety related equipment inside the shield building.
Corrective Actions: The licensee entered the condition into the corrective action program and evaluated the operability of the shield building.
Corrective Action References: CR-RBS-2022-00975 and CR-RBS-2022-02284
Performance Assessment:
Performance Deficiency: The failure to ensure a credited flood barrier was watertight is a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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 ensure the shield building hatch was watertight affected the design of the shield building to withstand the effects of a design basis flood event.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, appendix A, The Significance Determination Process for Findings At-Power.
Using exhibit 2, Mitigating System Screening Questions, the inspectors determined that the finding involved the loss or degradation of equipment or function specifically designed to mitigate a seismic, flooding, or severe weather initiating event for greater than 14 days. Using exhibit 4, External Events Screening Questions, the inspectors determined that the finding screened as very low safety significance (Green) because it did not degrade one or more trains of a system that supports a risk significant system or function and did not involve the total loss of any PRA function.
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.
Enforcement:
Violation: Title 10 of the Code of Federal Regulations (10 CFR) Part 50, appendix B, criterion III, Design Control, states, in part, measures shall be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. These measures shall include provisions to assure that appropriate quality standards are specified and included in design documents and that deviations from such standards are controlled.
Contrary to the above, from licensed operation until April 2022, for design of the shield building to protect containment from external flooding, to which 10 CFR Part 50, appendix B applies, the licensee failed to ensure the design as specified by the USAR was correctly translated into the specifications of the shield building hatch. Specifically, the licensee failed to ensure that the shield building hatch was adequately designed and constructed to protect the containment in a design basis flood event.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.
Failure to Maintain a Continuous Fire Watch when Required Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-02 Open/Closed
[H.8] -
Procedure Adherence 71111.05 The inspectors identified a Green finding and associated non-cited violation of River Bend Station, Unit 1, Renewed Facility Operating License, section 2.C(10), for failure to implement the fire protection program by not maintaining a continuous fire watch when required.
Specifically, during a period when a continuous fire watch was required to compensate for an inoperable detection and suppression system, the licensee failed to ensure a required fire watch was always present.
Description:
The inspectors reviewed the licensees implementation of compensatory measures for inoperable fire detection and suppression equipment. On January 10, 2022, the licensee commenced work on fire protection panel 2 which disabled fixed suppression system WS-6C covering fire zone cable area B on the 70-foot elevation of the control building. The licensee established a continuous fire watch to compensate for the inoperable equipment.
The River Bend Station, Unit 1, Renewed Facility Operating License, section 2.C(10), and attachment 4, requires that the licensee implement and maintain in effect all provisions of the approved fire protection program. Procedure SEP-FPP-RBS-001, River Bend Station Fire Protection Program, revision 7, step 5.1.7 states, Whenever a fire protection component is removed from service or found deficient, the impairment shall be documented and appropriate compensatory actions initiated. These compensatory actions shall remain in place until the impairment is restored. The licensees Technical Requirements Manual 3.7.9.2 requires them to enter condition A when a required spray or sprinkler system is nonfunctional and Establish a continuous fire watch with backup fire suppression equipment for those areas in which redundant systems or components could be damaged within one hour. Procedure SEP-FPP-RBS-005, River Bend Station Duties of Fire Watch, revision 2, step 5.9.1 states, The Continuous Fire Watch remains at the work site until relieved or directed by the responsible Maintenance Supervisor or Operations to secure the continuous fire watch, or upon plant evacuation. Entergy Procedure EN-OP-139, Fire Watch Program, step 7.1.2.3 states A Continuous Administrative Fire Watch shall not leave the post unless relieved by another Fire Watch or as otherwise directed by the Shift Manager.
The inspectors reviewed fire watch logs and card reader records from portions of the time period during which the fire watch was required to be stationed. Based on this review and discussions with licensee personnel, the inspectors determined that the assigned fire watch left the control building at 06:14:15 and a qualified fire watch who could provide a relief entered the control building at 06:15:24. The inspectors determined that the location of the card reader used and the fire watch location were far enough away to assume approximately 30 seconds travel time, resulting in approximately 2 minutes between the assigned fire watch leaving and the relief arriving. The inspectors could not establish that any other qualified fire watch was present during that time. Based on this review, the NRC determined that the licensee failed to maintain a continuous fire watch when required.
Corrective Actions: The licensee interviewed the personnel involved and entered the issue into their corrective action program.
Corrective Action References: CR-RBS-2021-06648
Performance Assessment:
Performance Deficiency: The failure to maintain a continuous fire watch when required is a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors 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 finding represented a loss of compensatory measures needed for fixed fire suppression equipment.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, appendix F, Fire Protection Significance Determination Process. Using Inspection Manual Chapter 0609, attachment 04, Initial Characterization of Findings, the inspectors determined the finding was associated with the Mitigating Systems cornerstone.
Using Inspection Manual Chapter 0609, appendix F, Fire Protection Significance Determination Process, the inspectors determined the finding was associated with fire confinement and was assigned a high degradation rating. The inspectors used step 1.4.2 to determine that the finding required an evaluation by a senior reactor analyst to determine whether a Phase 2 evaluation was required.
The analyst determined that the only significant source of increase in core damage frequency would result from internal fire scenarios. After judging the licensee had a fire probabilistic risk assessment model capable of adequately evaluating the fire risk associated with the finding, the analyst requested the fire initiation frequency for all fire scenarios for fire zone C06, cable area B, from the licensee. The licensee provided the requested information which composed the total initiation frequency of 8.8E-5/year. The analyst assumed an exposure time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or 1.1E-4 years, and coupled it with the conservative assumption that any fire which started in fire zone C06 would lead to core damage. Combining these inputs yielded an estimate of the increase in core damage frequency of 1.0E-8/year or characterized with very low safety significance (Green).
Cross-Cutting Aspect: H.8 - Procedure Adherence: Individuals follow processes, procedures, and work instructions. The inspectors determined that the fire watch personnel did not follow procedures to maintain the fire watch unless directed to leave by the responsible supervisor.
Enforcement:
Violation: The River Bend Station, Unit 1, Renewed Facility Operating License, section 2.C(10) and attachment 4, requires that the licensee implement and maintain in effect all provisions of the approved fire protection program. The approved fire protection plan requires that a continuous fire watch be established with backup fire suppression equipment for those areas in which redundant systems or components could be damaged when the required spray or sprinkler system is nonfunctional. The approved fire protection plan also requires that the continuous fire watch remain at the work site until relieved or directed to secure the continuous fire watch.
Contrary to the above, on January 12, 2022, a continuous fire watch required to be in an area affected by nonfunctional spray or sprinkler systems left the assigned area without being relieved or directed to secure the continuous fire watch.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.
Failure to Demonstrate Effective Control of Performance of a Maintenance Rule (a)(2)
System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-03 Open/Closed None (NPP)71111.12 The inspectors identified a Green finding and associated non-cited violation of 10 CFR 50.65(a)(2) for failure to demonstrate the effective control of performance of a maintenance rule scoped system through appropriate preventive maintenance. Specifically, the licensee failed to adequately monitor performance of the standby cooling tower, a maintenance rule scoped structure, in accordance with their preventive maintenance program and also did not implement (a)(1) goals and corrective actions.
Description:
The licensee maintains a structural monitoring program for maintenance rule structures per fleet Procedure EN-DC-150, Condition Monitoring of Maintenance Rule Structures. In accordance with that procedure, the standby cooling tower (SBCT) is classified as a high-risk structure and therefore it needs to be monitored every 5 years to meet the performance monitoring criteria for (a)(2). Procedure EN-DC-150, section 7.1 states that you must classify a structure Maintenance Rule (a)(1) if you exceed the monitoring interval plus an allowed 120-day grace period. Section 7.1.5 describes attributes to be inspected, including the roof, roof lining, scuppers, barriers, etc. Section 7.1 gives an additional allowance to extend certain inaccessible areas to be given an extended 10-year interval, but those areas must be identified, documented, and inspected within the extended interval.
The licensee conducted the required structural monitoring inspections of the SBCT in 2009, 2013, 2014, and 2019. The inspections for 2013, 2014, and 2019 were documented in reports RBS-CS-13-00004,14-00005, and 19-00004. Condition report CR-RBS-2012-02804 documents the missing report for the 2009 inspection. Prior to these inspections the licensee had made the roof inaccessible due to a modification to the roof access doors. The licensee failed to record in any of these inspections that the roof was inaccessible and the required inspections were not completed. As a result, the licensee had not inspected the roof during any of these structural walkdowns, and therefore failed to demonstrate performance of the structure which required them to classify the structure as (a)(1) per Procedure EN-DC-150.
Corrective Actions: The licensee obtained drone footage of the SBCT roof to verify the scuppers and roof were functional, in good condition, and clear of debris. They performed an analysis to show that with functional scuppers, a failure of the doors would not challenge a safety function. They additionally wrote a condition report to document that they failed to place the SBCT in (a)(1) after missing the grace period.
Corrective Action References: CR-RBS-2022-02997
Performance Assessment:
Performance Deficiency: The failure to monitor the performance or demonstrate effective control of performance of systems covered by the maintenance rule is a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors 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, a failure to demonstrate adequate performance could result in loss of protection against a design basis flooding event.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, appendix A, The Significance Determination Process for Findings At-Power.
The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, attachment 04, Initial Characterization of Findings, dated October 7, 2016, and determined that the finding was associated with the Mitigating Systems cornerstone.
Using Inspection Manual Chapter 0609, appendix A, The Significance Determination Process For Findings At-Power, exhibit 2, Mitigating Systems Screening Questions, section B, External Event Mitigating Systems (Seismic/Flood/Severe Weather Protection)screening questions, the inspectors determined the finding was of very low safety significance (Green) because the finding did not represent a loss or degradation of equipment or function designed to mitigate a flooding event for greater than 14 days.
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.
Enforcement:
Violation: As required by 10 CFR 50.65(a)(1), the holders of an operating license shall monitor the performance or condition of SSCs within the scope of the rule as defined by 10 CFR 50.65(b), against licensee-established goals, in a manner sufficient to provide reasonable assurance that such SSCs are capable of fulfilling their intended functions.
As required by 10 CFR 50.65(a)(2), that monitoring as specified in 10 CFR 50.65(a)(1) is not required where it has been demonstrated that the performance or condition of an SSC is being effectively controlled through the performance of appropriate preventive maintenance, such that the SSC remains capable of performing its intended function.
Contrary to the above, from 2009 to 2022, the licensee failed to demonstrate that the performance or condition of an SSC is being effectively controlled through the performance of appropriate preventive maintenance. Specifically, the licensee failed to monitor the SBCT roof in accordance with their prescribed monitoring interval and then failed to place the structure in (a)(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 Conduct Adequate Operability Determinations Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2022002-04 Open/Closed
[H.12] - Avoid Complacency 71111.15 The inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, appendix B, criterion V, Instructions, Procedures, and Drawings, with two examples, for failure to follow procedure EN-OP-104, Operability Determination Process, revision 17, a quality related procedure. Specifically, the licensee failed to perform a detailed operability evaluation when required for a degraded condition on the reactor core isolation cooling pressure transmitter and for non-conforming door seals on the roof of the standby cooling tower.
Description:
The first example is related to the reactor core isolation cooling (RCIC) steam line isolation transmitter, E31-PDTN084B. This pressure transmitter detects high steam flow indicative of a steam line break and provides an automatic isolation signal to the primary containment isolation valve (PCIV). While doing a routine procedure to calibrate the transmitter, the technicians noticed degraded wiring internal to the transmitter which made the transmitter inoperable. This was documented in condition report CR-RBS-2021-06467.
The licensee performed a causal analysis and concluded that moisture intrusion caused the insulation on the wiring to degrade and break away, leaving the wire exposed. The exposed wire was corrected, and the licensee determined the most likely source of the leak was from one of three sealed mechanical joints. During a walkdown, the licensee identified one of the seals on the conduit as potentially having inadequate thread engagement. This condition was documented in condition report CR-RBS-2021-07379. The licensee performed an immediate operability determination and concluded that the transmitter was operable because there was a possibility that the seal was adequate, and they had insufficient evidence that it was not.
They then decided to confirm the seals were adequately torqued at a future time.
Licensee Procedure EN-OP-104, step 8.2.9 states that if the immediate determination is based on engineering judgment or assumptions that have not been validated, then an operability evaluation should be considered. The operability evaluation is a more rigorous process that would include analysis and investigation to support its conclusions. The inspectors determined that the licensee failed to consider the environmental qualification (EQ)of the transmitter as a requirement for operability. The licensees causal analysis identified moisture intrusion as a cause of the degraded wire. The inspectors found that, based on the evidence of moisture intrusion and the appearance of inadequate thread engagement, the licensees assumption that the seal was adequate was not validated. The licensee should have performed a more detailed evaluation to confirm that the transmitter met its EQ requirements.
The second example is for the standby cooling tower (SBCT) roof doors SS-154-01 and SS-154-02. These doors are required to be watertight per their design specification. However, these doors are welded shut and therefore the licensee was unable to perform preventive maintenance (PM) monitoring of the watertight function of the doors. During intense precipitation, the roof of the SBCT is susceptible to a ponding level of two feet, 4 inches. The licensee has two 4-inch scuppers on the roof that could provide drainage from the roof area.
Since the doors to the roof are welded shut, the licensee had not performed inspections to confirm that the scuppers were functional. The inspectors questions prompted the licensee to generate condition report CR-RBS-2022-02367. The licensee performed an immediate operability determination and concluded that the SBCT was operable because the doors were inspected under work orders 572714 and 572715 and the scuppers would be adequate to drain the roof. The inspectors observed that the work orders identified documented that the workers were unable to inspect the doors seals. They also noted that the licensee had not inspected the scuppers to ensure they were clear. The inspectors determined that the licensee had not validated the assumptions used in the immediate determination and needed to perform a more detailed operability evaluation.
Corrective Actions: The licensee performed additional verification to confirm the RCIC transmitter met its EQ requirements and performed remote visual inspections of the SBCT roof scuppers to confirm they were clear. They also performed calculations to show that the scuppers would maintain water level below the level of the doors.
Corrective Action References: CR-RBS-2022-03887
Performance Assessment:
Performance Deficiency: The failure to follow the operability determination process procedure EN-OP-104 is a performance deficiency.
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, if the licensee fails to validate assumptions used in operability determinations, they could incorrectly determine a system is operable when it does not meet its licensing basis requirements.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, appendix A, The Significance Determination Process for Findings At-Power.
The inspectors determined that the finding was of very low safety significance (Green)because, in each example, the degraded condition did not represent a loss of a probabilistic risk assessment function in any exhibit 2.A scenario.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. In each example, the licensee made assumptions without validating them.
Enforcement:
Violation: As required by 10 CFR Part 50, appendix B, criterion V, Instructions, Procedures, and Drawings, activities affecting quality should be accomplished in accordance with instructions and procedures of a type appropriate to the circumstances. The licensee-maintained Procedure EN-OP-104, Operability Determination Process, to perform operability determinations for conditions adverse to quality, an activity affecting quality.
Contrary to the above, on December 9, 2021, and April 21, 2022, the licensee failed to perform an activity affecting quality in accordance with the prescribed procedure. Specifically, the licensee failed to perform operability determinations in accordance with Procedure EN-OP-104, Operability Determination Process, to which 10 CFR Part 50, appendix B applies.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.
Failure to Follow Breaker Maintenance Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000458/2022002-05 Open/Closed
[H.5] - Work Management 71153 A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a was identified when the licensee failed to implement written procedures covering activities recommended in Regulatory Guide 1.33, revision 2, appendix A.
Specifically, the licensee failed to follow procedures for reinstalling circuit breakers into switchgear, which resulted in the inoperability of safety-related equipment for longer than the allowed outage time.
Description:
On April 8, 2021, the control building chiller HVK-CHL1D failed to start while River Bend Station was shifting the operating chiller division. The licensee declared the chiller inoperable and attempted to find the cause. The licensee determined that the chiller failed to start because the 52PS switch, which actuates when the breaker is properly racked in the switchgear, had failed to actuate. The licensee determined that this had occurred when they installed the breaker following maintenance on March 12, 2021.
The control building chilled water system at River Bend Station consists of two divisions of two chillers each. One chiller in each division must be aligned to automatically start on demand for the system to be considered operable. For division II, either chiller 1B or 1D must be operable. On March 30, 2021, HVK-CHL1D was placed in standby for division II. At the time, it was not able to perform its safety function due to the misaligned switch. It remained inoperable until the condition was revealed on April 8, resulting in division II of control building chilled water being inoperable for approximately nine days. The allowed outage time for one division is 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
The licensee determined that when reinstalling the breaker following maintenance, they had failed to perform a functional test of the breaker to verify it was properly reinstalled. Licensee Procedure OSP-0052, Breaker Racking And 13.8 KV To 480 VAC Transformer Disconnect Operations, has the following guidance:
Step 7.1.2.2.10.n: For safety-related equipment perform a breaker functional test of breaker when racking in operation is completed.
The licensee determined that the person approving the removal of the clearance associated with the maintenance assumed the breaker functional test had been performed as part of the clearance removal but did not verify this assumption. The workers removing the clearance tags assumed the breaker functional test would be performed by another group. The licensee found no evidence that any functional testing was performed on the HVK-CHL1D breaker following its reinstallation.
Corrective Actions: The breaker was racked out, reinstalled, and tested.
Corrective Action References: CR-RBS-2021-03191
Performance Assessment:
Performance Deficiency: The failure to follow procedures for racking safety-related breakers is a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the failure to perform breaker functional checks resulted in control building chiller 1D being inoperable while relied upon for meeting a limiting condition of operation.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, appendix A, The Significance Determination Process for Findings At-Power.
Using exhibit 1, Mitigating Systems Screening Questions, the finding was screened as very low safety significance (Green) because although one train of a multi-train technical specification system was inoperable for greater than its allowed outage time, it did not represent a loss of the probability risk assessment function of one train of a multi-train technical specification system for greater than its technical specification allowed outage time.
Cross-Cutting Aspect: H.5 - Work Management: The organization implements a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority. The work process includes the identification and management of risk commensurate to the work and the need for coordination with different groups or job activities. Specifically, the work groups coordinating the restoration of the control building air conditioning system failed to ensure that the breaker test was performed.
Enforcement:
Violation: Technical Specification 5.4.1.a, requires, in part, that procedures shall be established, implemented, and maintained covering the activities recommended in appendix A of Regulatory Guide 1.33, revision 2. Section 4.s of appendix A to Regulatory Guide 1.33, revision 2, requires that instructions for energizing and startup should be prepared as appropriate for the control building heating and ventilation systems. The licensee established Procedure OSP-0052, Breaker Racking And 13.8 KV To 480 VAC Transformer Disconnect Operations, to cover those activities.
Contrary to the above, on March 12, 2021, the licensee failed to establish, implement, and maintain procedures recommended by appendix A of Regulatory Guide 1.33, revision 2.
Specifically, the licensee did not perform step 7.1.2.2.10.n of Procedure OSP-0052 when racking in the safety-related breaker for control building chiller 1D.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On July 7, 2022, the inspectors presented the integrated inspection results to Mr. Robert Walpole, Director, Regulatory Assurance and Performance Improvement, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR-RBS-
22-00975, 2022-02284
Miscellaneous
210.460
Specification for Missile Protected Doors
Work Orders
Corrective Action
Documents
CR-RBS-
22-02388
Engineering
Changes
Fire Detection System Upgrade - Phase I
Miscellaneous
SEP-FPP-RBS-
005
River Bend Station Duties of the Fire Watch
CB-070-103
Cable Area B, Fire Area C-6
Procedures
Fire Watch Program
Corrective Action
Documents
CR-RBS-
2012-02804, 2022-02074, 2022-02672, 2022-02997
EA-006AJ
Door Locations Standby Service Water Cooling Tower
Drawings
EA-059C
Partial Roof Plans & Dets Standby Service Water Cooling
Tower
MR 85-0445
Add Welded Bar to Secure Door
N/A
RBS-CS-05-
00001
2005 Maintenance Rule Structures Periodic Assessment
RBS-CS-13-
00004
RF-17 Maintenance Rule Structures Periodic Assessment of
Drywell, Standby Cooling Tower, and Heater Bay Area
RBS-CS-14-
00001
2014 Maintenance Rule Structures Periodic Assessment
Miscellaneous
RBS-CS-19-
00004
2019 Maintenance Rule Structures Periodic Assessment
Procedures
Condition Monitoring of Maintenance Rule Structures
Corrective Action
Documents
CR-RBS-
21-06467, 2021-06490, 2021-07379, 2022-00061, 2022-
2343, 2022-02367
Miscellaneous
24.150-000-
096A
EQR Pressure Transmitters 1152
10/07/1985
Procedures
Operability Determination Process
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Orders
WO 00572712, 00572715
Corrective Action
Documents
CR-RBS-
21-03191, 2021-03343, 2022-02591
Operations General Administrative Guidelines
116
Breaker Racking and 13.8 KV TO 480 VAC Transformer
Disconnect Operations
Procedures
Breaker Racking and 13.8 KV TO 480 VAC Transformer
Disconnect Operations
Work Orders
WO 00560583, 52896197, 52896349