IR 05000458/2020002
| ML20212L420 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 07/30/2020 |
| From: | David Proulx NRC/RGN-IV/DRP/RPB-C |
| To: | Vercelli S Entergy Operations |
| References | |
| IR 2020002 | |
| Download: ML20212L420 (16) | |
Text
July 30, 2020
SUBJECT:
RIVER BEND STATION - INTEGRATED INSPECTION REPORT 05000458/2020002
Dear Mr. Vercelli:
On June 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at River Bend Station. On July 8, 2020, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding did not involve a violation of NRC requirements.
A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as a non-cited violation (NCV)
consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation 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 or a finding not associated with a regulatory requirement 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, David L. Proulx, Acting Chief Reactor Projects Branch C Division of Reactor Projects
Docket No. 05000458 License No. NPF-47
Enclosure:
As stated
Inspection Report
Docket Number:
05000458
License Number:
Report Number:
Enterprise Identifier: I-2020-002-0005
Licensee:
Entergy Operations, Inc.
Facility:
River Bend Station
Location:
St. Francisville, LA
Inspection Dates:
April 1, 2020 to June 30, 2020
Inspectors:
R. Kumana, Senior Resident Inspector
R. Alexander, Senior Emergency Preparedness Inspector
B. Parks, Resident Inspector
Approved By:
David L. Proulx, Acting Chief
Reactor Projects Branch C
Division of Reactor Projects
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. A licensee-identified non-cited violation is documented in report section 7115
List of Findings and Violations
Improper Maintenance Leads to Inoperability of Automatic Depressurization System Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green FIN 05000458/2020002-01 Open/Closed
[H.5] - Work Management 71153 The inspectors reviewed a self-revealed Green finding for the licensees failure to conduct maintenance in accordance with procedures. Specifically, during the rebuilding of safety vent valves SVV-AOV40B and SVV-AOV41D, the licensee failed to properly seat the O-rings in accordance with the work order instruction and vendor manual guidance. Excessive leakage from the valves created a condition in which the running safety vent valve air compressor tripped on thermal overload, causing pressure in the automatic depressurization system header to fall below the minimum value required by technical specifications.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000458/2019-004-00 Potential Loss of Safety Function for all ADS (Automatic Depressurization System) Valves 71153 Closed
PLANT STATUS
River Bend Station began the inspection period at rated thermal power. On April 7, 2020, the station conducted a downpower to approximately 68 percent power to conduct power suppression testing and a control rod sequence exchange. The unit was returned to rated thermal power on April 15, 2020. On June 26, 2020, the station reduced power to approximately 65 percent power to conduct a control rod sequence exchange. The unit was returned to rated thermal power on June 30, 2020. The unit remained at 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 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.
Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), resident inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time the resident inspectors performed periodic site visits each week and during that time conducted plant status activities as described in IMC 2515, Appendix D; observed risk significant activities; and completed on site portions of IPs. In addition, resident and regional baseline inspections were evaluated to determine if all or a portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors verified the adequacy of the overall preparations to protect risk-significant systems from impending severe weather due to Tropical Storm Cristobal on June 8, 2020.
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Division I standby switchgear on May 16, 2020
- (2) Backup DC battery charger on May 26, 2020
- (3) Division I remote shutdown panel on June 1, 2020
- (4) Division II standby service water on June 10, 2020
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the Division III emergency diesel generator on June 18, 2020.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 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) Standby switchgear 1A room, fire area C-15, on May 16, 2020
- (2) Cable chase I, fire area C-1, on May 28, 2020
- (3) Standby gas treatment system filter A room, fire area AB-14, on June 8, 2020
- (4) Standby cooling tower pump B room, fire area PH-2/Z-1, on June 10, 2020
- (5) E tunnel west, F tunnel, and G tunnel, fire area PT-1, on June 15, 2020
- (6) Diesel generator C room, fire area DG-5/Z-1, on June 18, 2020
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) Division III emergency diesel generator room on June 30, 2020
71111.07A - Heat Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) Spent fuel pool A heat exchanger on May 27, 2020
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 emergency core cooling system testing on June 23, 2020.
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 remain capable of performing their intended function:
- (1) Functional failure review of the low pressure core spray system on May 12, 2020
- (2) Review of 10 CFR 50.65 (a)(1) corrective actions for the remote shutdown system on June 16, 2020
- (3) Review of periodic maintenance rule assessment on June 22, 2020
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (5 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) Green risk while FLEX emergency diesel generators non-functional on April 1, 2020
- (2) Yellow risk during Division I residual heat removal pump and diesel generator maintenance on April 6, 2020
- (3) Elevated risk with risk mitigating actions for feedwater pump B seal replacement on April 9, 2020
- (4) Risk mitigating actions for degraded fuel pool cooling heat exchanger on May 8, 2020
- (5) Yellow risk during Division II containment unit cooler and diesel generator maintenance on June 5, 2020
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Division I emergency diesel generator after generator field amps found high out of specification during testing on April 8, 2020 (CR-RBS-2020-01500)
- (2) Division II automatic depressurization system after failed surveillance testing on trip unit E12-N656C on April 30, 2020 (CR-RBS-2020-01855)
- (3) Control building chiller D with degraded insulation on May 19, 2020 (CR-RBS-2020-01851)
- (4) Standby service water with nonconforming flood protection barrier on June 17, 2020 (CR-RBS-2020-02385)
- (5) Preferred transformer RTX-XSR1D after receipt of a locked in open phase detection alarm on June 23, 2020 (CR-RBS-2020-02562)
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:
- (1) Work Order (WO) 46140801 following replacement of service water pump D discharge check valve on May 20, 2020
- (2) WO 50538523 following replacement of spent fuel pool cooling pump 1A bearing on May 20, 2020
- (3) WO 52829544 following residual heat removal C line fill pump oil replacement on June 4, 2020
- (4) WO 52928694 following unexpected trip of compressor LSV-C3A on June 5, 2020
- (5) WO 52853877 following Division I residual heat removal relay replacement on June 25, 2020
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) STP-257-3601, Inservice Testing of Division I Standby Gas Treatment Filtration System, Revision 13, on April 14, 2019
- (2) STP-209-3818, RCIC Penetration KJB-Z15 Valve Leak Rate Test, Revision 14, on May 1, 2020
- (3) STP-309-0206, Division I Diesel Generator 184 Day Operability Test, Revision 31, on May 4, 2020
RCS Leakage Detection Testing (IP Section 03.01) (1 Sample)
- (1) STP-207-4550, RCS-Leakage Detection System-Drywell and Pedestal Floor Drain Sump Monitoring Channel Functional Test (DFR-ESX105, DFR-LI105, DFR-ESX128, DFR-LI128, DER-KC174), Revision 11, on April 24, 2020
FLEX Testing (IP Section 03.02) (1 Sample)
- (1) Maintenance work order 519028-01, FLX P-1 Grease, Uncouple Motor Run, Revision 8/5/2019, on April 1, 2020
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.01-02.03) (1 Sample)
- (1) The inspectors evaluated the following Emergency Action Level procedure and Emergency Plan changes, all of which were submitted to the NRC within 30 days of implementation in accordance with 10 CFR 50.54(q)(5) and 10 CFR 50.4.
River Bend Emergency Plan, Revisions 43, 44, and 45
EIP-2-001, Classifications, Revision 28
This evaluation does not constitute NRC approval.
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)
- (1) Emergency preparedness training drill on March 10,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03)===
- (1) January 2019 through December 2019
MS06: Emergency AC Power Systems (IP Section 02.05) (1 Sample)
- (1) April 2019 through March 2020
MS07: High Pressure Injection Systems (IP Section 02.06) (1 Sample)
- (1) April 2019 through March 2020
MS08: Heat Removal Systems (IP Section 02.07) (1 Sample)
- (1) April 2019 through March 2020
71152 - Problem Identification and Resolution
Semiannual Trend Review (IP Section 02.02) (1 Sample)
- (1) The inspectors reviewed the licensees corrective action program for potential adverse trends in equipment reliability that might be indicative of a more significant safety issue.
Observation
In 2019, the station documented an ongoing trend of poor performance in the area of equipment reliability. Examples of equipment issues that affected the station included a leak in fifth point feedwater heater A, a malfunctioning of feedwater heater level control system A, a fault in recirculation pump transformer A, leakage in a condenser water box, increased drywell leakage due to leakage in a check valve in the residual heat removal system, a trip of feed pump B while at power, a trip of automatic depressurization system compressor B while compressor A was out of service, a small through-wall leak on standby liquid control piping discovered while the plant was offline for an outage, failures of nuclear instruments during startup, and an oil leak in recirculation pump A. Additionally, the station experienced multiple surveillance test failures on safety-related and risk-significant equipment, to include a failure of containment unit coolers and a control building chiller to automatically start during loss of offsite power and loss of coolant accident testing and failures of FLEX components to start properly during scheduled testing conducted by the equipment vendor. These issues have been documented in the corrective action program and the adverse trend remains open in the licensees trending and performance review process.
For the first half of 2020, inspectors observed an improvement in the previously observed trend. The station experienced a smaller number of equipment failures, which included a failure of a standby control building chiller to automatically start during a post-maintenance test in which the running chiller had failed, an inability to establish test reference conditions in a spent fuel pool heat exchanger due to debris build up that rendered the heat exchanger non-functional, a failure of a controller in a division of the main steam positive leakage control system, and issues associated with the operation of instrument air compressors. The quantity and severity of equipment reliability issues during the period was significantly less than in the first half and second half of 2019. The adverse trend remains open in the licensee's corrective action trending and performance review process.
Annual Follow-up of Selected Issues (IP Section 02.03) (1 Sample)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) Failure to perform fire extinguisher maintenance under Condition Report CR-RBS-2019-07137 on June 30, 2020
71153 - Follow-up of Events and Notices of Enforcement Discretion Event Follow-up (IP Section 03.01)
- (1) The inspectors evaluated repeat failures of FLEX equipment and licensee's response on April 30, 2020.
Event Report (IP Section 03.02) (1 Sample)
The inspectors evaluated the following licensee event report (LER):
- (1) LER 05000458/2019-004-00, Potential Loss of Safety Function for all ADS (Automatic Depressurization System) Valves (ADAMS Accession No.
The inspection conclusions associated with this LER and an associated finding are documented in the Inspection Results section of this report.
INSPECTION RESULTS
Licensee-Identified Non-Cited Violation 71152 This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Violation: River Bend Station is required to maintain the approved fire protection program by License Condition C(10), Fire Protection (Section 9.5.1,SER and SSER 3), and 4 of NFP-47, Fire Protection Program Requirements. Section 9.5.1.2.11, Portable Extinguishers, of the FSAR states that fire extinguishers are to be provided using the guidance of NFPA 10, Standard for Portable Fire Extinguishers. NFPA 10 specifies requirements for inspection, maintenance, recharging, and hydrostatic testing requirements of fire extinguishers. Contrary to the above, the licensee failed to assure that fire extinguishers required by the approved fire protection program were maintained in accordance with the requirements of NFPA 10.
Significance/Severity: Green. The inspectors assessed the significance of the finding using Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. Using IMC 0609, 4, Initial Characterization of Findings, dated December 13, 2019, the finding was determined to require additional evaluation under IMC 0609, Appendix F, Fire Protection Significance Determination Process, dated May 2, 2018. The finding was screened as a Green finding of very low safety significance in accordance with Task 1.4.5, Manual Fire Fighting, Question A.
Corrective Action References: CR-RBS-2019-07137 and CR-RBS-2019-01613
Improper Maintenance Leads to Inoperability of Automatic Depressurization System (ADS)
Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green FIN 05000458/2020002-01 Open/Closed
[H.5] - Work Management 71153 The inspectors reviewed a self-revealed Green finding for the licensees failure to conduct maintenance in accordance with procedures. Specifically, during the rebuilding of safety vent valves (SVVs) SVV-AOV40B and SVV-AOV41D, the licensee failed to properly seat the O-rings in accordance with the work order instruction and vendor manual guidance. Excessive leakage from the valves created a condition in which the running SVV air compressor tripped on thermal overload, causing pressure in the ADS header to fall below the minimum value required by technical specifications (TS).
Description:
On October 24, 2019, with the reactor operating at approximately 100 percent power, the station completed scheduled maintenance on non-safety related SVV compressor B. Approximately one hour after removing tags associated with the maintenance and lining up the system, the station received a main control room alarm indicating low pressure in the ADS supply header A. At the time, pressure in the header was at 151 psig and lowering.
In response to the lowering pressure, operators attempted to start SVV compressor A. The starting attempt was unsuccessful because the thermal overloads on the compressor had tripped. With no replenishment of air to the header, pressure continued to drop and eventually fell below 131 psig, the minimum pressure specified in the TS surveillance testing requirement for the ADS system. The station therefore declared all ADS valves inoperable.
Shortly after pressure fell below the 131 psig limit, operators started SVV compressor B, but its operation failed to restore pressure. The station was eventually able to restart SVV compressor A, which brought pressure back above the 131 psig surveillance testing requirement. Operators noted that the safety-related LSV compressor had also started and had successfully maintained pressure in the header above the minimum value necessary to maintain the safety function of ADS. The safety function was additionally maintained by check valves that prevent leakage out of the safety-related accumulators into the air header.
The licensee subsequently determined that the cause of the event was a failure to properly rebuild valves SVV-AOV40B and SVV-AOV41D during the maintenance window. Operators failed to correctly install O-rings on these valves in accordance with work order 52807862, step 4.1.8, and the vendor manual guidance on O-ring installation. As a result, they leaked excessively, impairing the ability of SVV compressor B to restore pressure and causing SVV compressor A to cycle excessively and eventually trip on thermal overload.
Corrective Actions: To correct the condition, the licensee rebuilt the leaking valves and conducted training and performance evaluations to evaluate whether gaps existed in O-ring installation.
Corrective Action References: CR-RBS-2019-06836
Performance Assessment:
Performance Deficiency: The failure to follow work order 52807862, step 4.1.8, and the guidance on O-ring installation in the vendor manual during maintenance on SVV valves was 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 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, by failing to properly install the O-rings in valves SVV-AOV40B and SVV-AOV41D, operators introduced a leak into the ADS supply header that caused pressure to fall below the minimum allowable surveillance value, rendering all ADS valves inoperable.
Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined that the finding was of very low safety significance (Green) because the event was not associated with a loss of the probabilistic risk assessment function of ADS. Even though pressure in the supply header fell below the minimum surveillance requirement for ADS to remain operable, the check valves in the ADS accumulators functioned as designed, preventing pressure inside the safety-related accumulators from falling below the level necessary to ensure operation of ADS valves in an event.
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 station failed to recognize that improperly rebuilding non-safety related valves SVV-AOV40B and SVV-AOV41D could cause leakage that could adversely impact safety-related equipment.
Enforcement:
Inspectors did not identify a violation of regulatory requirements associated with this finding.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On June 17, 2020, the inspectors presented the emergency plan/emergency action level changes in-office inspection results to J. Reynolds, Director, Regulatory Assurance and Performance Improvement, and other members of the licensee staff.
On July 8, 2020, the inspectors presented the integrated inspection results to S. Vercelli, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR-RBS-
20-02439
Corrective Action
Documents
CR-RBS-
20-02407, 2020-02540
Miscellaneous
Process Applicability Determination Form: Procedure
Revision/ EIP-2-001 Classification of Emergencies, Rev. 28
01/20/2020
Miscellaneous
Letter of Agreement between Entergy Operations, Inc. River
Bend Station and the Fire Protection District #1 of West
Feliciana Parish, Louisiana
2/12/2013
Miscellaneous
Letter from Fire Protection District No. 1 of West Feliciana
Parish to RBS, EP Manager; Subject: LOA
4/9/2018
Miscellaneous
50.54(Q) Screening & Evaluation Forms: River Bend Station
Emergency Plan, Rev. 44 (Revision 1)
06/08/2020
Miscellaneous
Process Applicability Determination Form: River Bend
Station Emergency Plan, Rev. 43 & On-Shift Staffing
Analysis, Rev. 1
10/23/2017
Miscellaneous
50.54(Q) Screening & Evaluation Forms: River Bend Station
Emergency Plan, Rev. 43 & On-Shift Staffing Analysis,
Rev. 1
10/23/2017
Miscellaneous
Process Applicability Determination Form: River Bend
Station Emergency Plan, Rev. 44
05/04/2019
Miscellaneous
Process Applicability Determination Form: River Bend
Station Emergency Plan, Rev. 45
11/11/2019
Miscellaneous
50.54(Q) Screening & Evaluation Forms: River Bend Station
Emergency Plan, Rev. 44
05/04/2019
Miscellaneous
50.54(Q) Screening & Evaluation Forms: River Bend Station
Emergency Plan, Rev. 45
11/19/2019
Miscellaneous
Letter of Agreement between Entergy Operations, Inc. River
Bend Station and St. Francisville Volunteer Fire Department
of West Feliciana Parish, Louisiana
2/12/2013
Miscellaneous
50.54(Q) Screening & Evaluation Forms: EIP-2-001, Rev. 28
01/20/2020
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
Emergency Planning 10CFR50.54(q) Review Program
& 8
Procedures
Process Applicability Determination
Miscellaneous
H&H Manufacturing Inc. Heatless Air Dryer Model HH-0030
S/N HH-5253-1 Instruction Manual
Work Orders