IR 05000313/2021001: Difference between revisions

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{{#Wiki_filter:May 06, 2021
 
==SUBJECT:==
ARKANSAS NUCLEAR ONE - INTEGRATED INSPECTION REPORT 05000313/2021001 AND 05000368/2021001
 
==Dear Mr. Dinelli:==
On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Arkansas Nuclear One. On April 8, 2021, the NRC inspectors discussed the results of this inspection with Mr. J. Sullivan, General Manager Plant Operations, 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.
 
If you disagree with 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 Arkansas Nuclear One. 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, John L. Digitally signed by John L. Dixon Dixon Date: 2021.05.06 15:05:13 -05'00'
John L. Dixon, Jr., Chief Reactor Projects Branch D Division of Reactor Projects Docket Nos. 05000313 and 05000368 License Nos. DPR-51 and NPF-6
 
===Enclosure:===
As stated
 
==Inspection Report==
Docket Numbers: 05000313 and 05000368 License Numbers: DPR-51 and NPF-6 Report Numbers: 05000313/2021001 and 05000368/2021001 Enterprise Identifier: I-2021-001-0050 Licensee: Entergy Operations, Inc.
 
Facility: Arkansas Nuclear One Location: Russellville, AR Inspection Dates: January 1, 2021 to March 31, 2021 Inspectors: R. Alexander, Senior Emergency Preparedness Inspector N. Brown, Resident Inspector R. Bywater, Senior Resident Inspector T. DeBey, Resident Inspector H. Freeman, Senior Project Engineer S. Hedger, Emergency Preparedness Inspector Approved By: John L. Dixon, Jr., Chief Reactor Projects Branch D Division of Reactor Projects Enclosure
 
=SUMMARY=
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Arkansas Nuclear One, 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===
 
Unit 2 Trip Due to Failure to Evaluate/Classify a Feedwater Control System Power Supply Component as Critical Equipment Cornerstone          Significance                                Cross-Cutting      Report Aspect            Section Initiating Events    Green                                      None              71153 FIN 05000368/2021001-01 Open/Closed The inspectors identified a Green finding for the licensees failure to properly evaluate and classify the Unit 2 main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.
 
===Additional Tracking Items===
Type        Issue Number              Title                            Report Section    Status LER        05000368/2020-001-00      Loss of Feedwater Control        71153            Closed System Power for Train 'A'
Feedwater that Resulted in Plant Trip
 
=PLANT STATUS=
 
Unit 1 began the inspection period at full power. On February 15, 2021, Unit 1 operators reduced power to 32 percent power at request of the grid operator to reduce station output.
 
Operators returned the unit to full power on February 18, 2021.
 
On March 14, 2021, Unit 1 was manually tripped from 99 percent power after a loss of voltage on bus A2 resulting from a continuity failure in a related potential transformer drawer. After repairs, operators restarted the reactor on March 17, placed the unit online on March 18, and raised power to 95 percent on March 21, 2021.
 
Unit 1 began an end-of-operating cycle power coastdown on March 29, 2021 and ended the inspection period at approximately 90 percent power.
 
Unit 2 began the inspection period at full power and remained at full power until January 10, 2021, when operators reduced power to 77 percent power to address a main feedwater pump B speed oscillation issue. After repairs, operators returned the unit to 90 percent power on January 12, 2021.
 
On January 13, 2021, Unit 2 operators reduced power to 86 percent power to complete repairs to address elevated condenser air in-leakage. After repairs, operators returned the unit to full power on January 14, 2021.
 
On January 26, 2021, Unit 2 operators performed a planned power reduction to 81 percent power to replace a backup power supply for the core operating limits supervisory system and perform main turbine control valve testing. Operators returned the unit to full power the same day without replacing the power supply after determining the observed core power distribution did not support removing the core operating limits supervisory system from service at the planned reduced power level.
 
On February 15, 2021, Unit 2 operators reduced power to 88 percent power at the request of the grid operator to reduce station output. Operators returned the unit to full power on February 17, 2021.
 
On March 4, 2021, Unit 2 operators reduced power to 65 percent power to replace the core operating limits supervisory system backup power supply. After completion of repairs, operators returned to unit to full power later that day and the unit remained at full 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 Disease 2019 (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; conducted plant status activities as described in IMC 2515, Appendix D, Plant Status; 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 portions 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==
 
==71111.04 - 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) Unit 1 decay heat removal/low-pressure injection train B during maintenance on train A on January 7, 2021
: (2) Unit 2 FLEX reactor coolant/steam generator pump placement on March 23, 2021
: (3) Unit 2 containment spray train A during maintenance on loop 1 service water to containment cooler service water isolation valve maintenance on March 30, 2021
: (4) Unit 2 motor-driven emergency feedwater train during turbine-driven emergency feedwater train flow transmitter maintenance on March 11, 2021
 
==71111.05 - Fire Protection==
 
===Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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) Unit 1 steam pipe room, Fire Zone 170-Z, on January 6, 2021
: (2) Unit 2 upper north electrical penetration room, Fire Zone 2183-J, on January 20, 2021
: (3) Unit 1 common feedwater pump room, Fire Zone 75-AA, on January 21, 2021
: (4) Common unit diesel fuel vaults, Fire Zone 1(2)B-ADD-DFV, on March 3, 2021
 
===Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)===
: (1) The inspectors evaluated the onsite fire brigade training and performance during an            unannounced fire drill on March 24, 2021.
 
==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 a Unit 2 planned down power to 65 percent and a subsequent power increase on March 4, 2021.
 
===Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)===
: (1) The inspectors observed and evaluated Unit 1 just-in-time training that was done in            preparation for the unit operation at reduced Tavg on March 10, 2021.
 
==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) Unit 2 emergent work activities for the atmospheric dump valve isolation valve 2CV-1002 failure to stroke due to motor failure on January 22, 2021
: (2) Unit 1 emergent work activities for the emergency feedwater initiation and control Channel B failure due to freezing steam generator pressure sensing lines on February 15, 2021
: (3) Unit 1 emergent work activities for the emergency feedwater initiation and control Channel D failure due to power supply failure on February 19, 2021
: (4) Unit 1 common feedwater injection to steam generator B valve CV-2660B maintenance on March 23, 2021
 
==71111.15 - Operability Determinations and Functionality Assessments==
 
===Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)===
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
: (1) Unit 1 operability determination for reactor building spray system after seat leakage through recirculation and test header isolation valve BS-2B was discovered during surveillance testing on February 3, 2021
: (2) Unit 1 operability determination for reactor building spray pump B suction pressure transmitter PT-2428 on February 5, 2021
: (3) Unit 1 operability determination for high-pressure injection pump P-36B on February 10, 2021
: (4) Unit 1 operability determination for emergency feedwater initiation and control channel B on February 19-22, 2021
: (5) Unit 1 operability determination for Unit 1 personnel airlock inner door seal on March 11, 2021
: (6) Unit 1 operability determination for service water pipe leak upstream of valve CV-3850, service water loop 1 to emergency feedwater supply valve on March 17, 2021
 
==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) ANO-1 End of Cycle 29 Tavg Reduction Maneuver on March 11-17, 2021
 
==71111.19 - Post-Maintenance Testing==
 
===Post-Maintenance Test Sample (IP Section 03.01) (1 Sample)===
The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:
: (1) Common unit diesel-driven fire pump P-6B post-maintenance testing after engine failure and replacement of starter motor on February 27, 2021
==71111.22 - Surveillance Testing==
 
The inspectors evaluated the following surveillance tests:
 
===Surveillance Tests (other) (IP Section 03.01)===
{{IP sample|IP=IP 71111.22|count=4}}
: (1) Unit 2 valve stroke surveillance for atmospheric dump isolation valve 2CV-1002 on January 26, 2021
: (2) Unit 1 valve stroke surveillance for service water sluice gates on February 3, 2021
: (3) Unit 1 emergency diesel generator 1 monthly surveillance run on February 7, 2021
: (4) Alternate ac diesel generator quarterly run on February 9, 2021
 
==71114.01 - Exercise Evaluation==
 
===Inspection Review (IP Section 02.01-02.11) (1 Sample)===
: (1) The inspectors evaluated the biennial emergency plan exercise conducted on March 23, 2021. The exercise scenario simulated a reactor coolant pump malfunction causing fuel damage, a steam generator tube rupture associated with a stuck open safety-relief valve, and demonstrations of extensive damage mitigation strategies consistent with 10 CFR 50.155(b)(2).
 
==71114.04 - Emergency Action Level and Emergency Plan Changes==
 
===Inspection Review (IP Section 02.01-02.03) (1 Sample)===
: (1) The licensee submitted a summary of emergency plan changes (Revision 46) to the NRC on December 2, 2020. The inspectors conducted a review of the changes from March 1 to March 31, 2021. 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) The inspectors evaluated an emergency planning drill involving a tornado event which damaged plant equipment on March 9, 2021.
 
==71114.08 - Exercise Evaluation Scenario Review==
 
===Inspection Review (IP Section 02.01 - 02.04) (1 Sample)===
: (1) The inspectors reviewed and evaluated the proposed scenario for the biennial          emergency plan exercise on March 23,
 
==OTHER ACTIVITIES - BASELINE==
 
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
EP01: Drill/Exercise Performance (IP Section 03.12) ===
{{IP sample|IP=IP 71151|count=1}}
: (1) Units 1 and 2 (July 1, 2020 through December 31, 2020)
 
===IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 03.01) (2 Samples)===
: (1) Unit 1 (January 1, 2020 through December 31, 2020)
: (2) Unit 2 (January 1, 2020 through December 31, 2020)
 
===EP02: ERO Drill Participation (IP Section 03.13) (1 Sample)===
: (1) Units 1 and 2 (July 1, 2020, through December 31, 2020)
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02)
(2 Samples)
: (1) Unit 1 (January 1, 2020 through December 31, 2020)
: (2) Unit 2 (January 1, 2020 through December 31, 2020)
 
===EP03: Alert & Notification System Reliability (IP Section 03.14) (1 Sample)===
: (1) Units 1 and 2 (July 1, 2020 through December 31, 2020)
 
===IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 03.03) (2 Samples)===
: (1) Unit 1 (January 1, 2020 through December 31, 2020)
: (2) Unit 2 (January 1, 2020 through December 31, 2020)
 
===71153 - Follow up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02) ===
{{IP sample|IP=IP 71153|count=1}}
The inspectors evaluated the following licensee event reports (LERs):
: (1) LER 05000368/2020-001-00, Loss of Feedwater Control System Power for Train A Feedwater that Resulted in Plant Trip (ADAMS Accession No. ML21039A557). The inspection conclusions associated with this LER are documented in this report as Finding 05000368/2021001-01.
 
==INSPECTION RESULTS==
Unit 2 Trip Due to Failure to Evaluate/Classify a Feedwater Control System Power Supply Component as Critical Equipment Cornerstone          Significance                              Cross-Cutting      Report Aspect            Section Initiating Events    Green                                      None              71153 FIN 05000368/2021001-01 Open/Closed The inspectors identified a Green finding for the licensees failure to properly evaluate and classify the Unit 2 main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.
 
=====Description:=====
On December 10, 2020, while operating at full power, the ANO Unit 2 reactor experienced a loss of main feedwater flow through the A main feedwater train due to a complete loss of A main feedwater control system electrical power. That power loss prevented the expected system response and associated alarms and indications for a loss of main feedwater train from occurring. The A main feedwater pump turbine went to minimum speed, the A main feedwater control valve shut, and manual control of the A main feedwater train was not possible. While the licensed operators recognized there was a problem with the main feedwater system, the reactor automatically tripped on A low steam generator water level before they could take any action. Post-trip investigation showed that the A main feedwater control system had experienced a complete loss of power even though it had redundant power supplies. The failure of one power supply should not cause complete loss of system power. Initial troubleshooting did not identify the cause of the event. After cycling the input power switches to the power supplies, both supplies came on and provided voltage outputs that were within specifications. Some components of the individual power supplies in the A main feedwater control system were replaced (although they were not failed) and the reactor was returned to power.
 
The inspectors independently reviewed the event and questioned the licensee whether there was a downstream electrolytic capacitor that could have caused the loss of power. The licensee evaluated that potential and concluded that a capacitor in a filter assembly downstream of the redundant power supplies was the likely cause of the event. Since a functional failure of a capacitor in the filter assembly would cause a complete loss of power to the main feedwater control system, it would cause a plant trip. That vulnerability should have led to the capacitor filter assembly having been classified as a critical component in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21, Section 5.2, Step 4. Components classified as critical shall be included in the PM [preventive maintenance] program and have a Maintenance Strategy developed in accordance with Procedure EN-DC-335. Since the downstream filter capacitors had not been classified, there was no preventive maintenance strategy for them. In fact, the licensee could not find any evidence that any maintenance had ever been performed. That resulted in electrolytic capacitors that were more than 25 years old being in the system. Per the sites Operational Decision Making document for this event, the electrolytic capacitors should have changed out per our SPV [single point vulnerability] PM fleet strategy on a 6 year interval.
 
The engineering review for the power supply installation in 1995 failed to identify the vulnerability.
 
Corrective Actions: The A train main feedwater control system power supplies for Unit 2 were reset and preventive maintenance activities were performed. A voltage monitor was set up to provide detailed data for future analysis of any similar future events. An apparent cause analysis was performed, and classification reviews of other redundant power supply systems are being performed. The site has classified the filter assemblies as single point vulnerabilities per Procedure EN-DC-175 but the critical equipment classification has not yet been completed. Future activities are being planned to redesign the main feedwater control system power supplies so that the common filter assembly is removed. The licensee submitted Licensee Event Report LER 05000368/2020-001-00.
 
Corrective Action References: Condition Report CR-ANO-2-2020-03843 and associated Apparent Causal Analysis CR-ANO-2-2020-03913
 
=====Performance Assessment:=====
Performance Deficiency: The licensees failure to properly evaluate and classify the main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21, was a performance deficiency. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.
 
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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 unrecognized single point vulnerability of the power supply filter assembly led to the vulnerability not being mitigated and caused a complete loss of electrical power to the A main feedwater control system that resulted in a plant trip.
 
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 had very low safety significance (Green) because the finding did not cause a reactor trip AND the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition.
 
Cross-Cutting Aspect: None. The original equipment classification error occurred when the power supplies were installed in 1995 and an additional missed opportunity to identify the issue occurred in 2015 when the system was reviewed during a site-wide Component Criticality Validation Sample Review was done as part of the ANO Comprehensive Recovery Plan. This missed opportunity was not considered to be reflective of present licensee performance.
 
=====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 February 18, 2021, the inspectors presented the emergency exercise preliminary scenario review inspection results to Mr. J. Toben, Manager, Emergency Preparedness, and other members of the licensee staff.
* On April 8, 2021, the inspectors presented the emergency preparedness exercise inspection results to Mr. J. Sullivan, General Manager Plant Operations, and other members of the licensee staff.
* On April 8, 2021, the inspectors presented the integrated inspection results to Mr. J. Sullivan, General Manager Plant Operations, and other members of the licensee staff.
 
THIRD PARTY REVIEWS The inspectors reviewed a World Association of Nuclear Operators report during the inspection period.
 
=DOCUMENTS REVIEWED=
 
Inspection Type              Designation      Description or Title                                    Revision or
Procedure                                                                                            Date
71111.04  Corrective Action CR-ANO-          1-2020-00824, 1-2020-01378, 1-2020-01509, 1-2020-01678,
Documents                          1-2020-01945, 2-2021-00464
71111.04  Drawings          M2210, Sheet 3  Service Water System                                    92
71111.04  Drawings          M2236, Sheet 1  Containment Spray System                                96
71111.04  Procedures        OP-1104.004      Decay Heat Removal Operating Procedure                  132
OP-2106.006      Emergency Feedwater System Operations                  104
71111.04  Work Orders      WO              52894842, 52911085
71111.05  Corrective Action CR-ANO-          1-2021-00031, 1-2021-00345, 2-2020-03887, 2-2021-00142,
Documents                          2-2021-00521, C-2020-02793, C-2021-00858
71111.05  Drawings          FP-109          Fire Zones Emergency Diesel Fuel Storage Vault          8
71111.05  Drawings          FP-2103          El 368-0 and 372-0                                  38
71111.05  Drawings          FP-2103, Sheet 1 El 368-0 and 372-0                                  38
71111.05  Drawings          FP-2111          Fire Zones Emergency Diesel Fuel Storage Vault          8
71111.05  Drawings          FZ-2027          Fire Zone Electrical Equipment Room                    4
71111.05  Fire Plans        U1 PreFire Plan  Fire Zone 1B-ADD-DFV, Fire Area L (Diesel Fuel Vault)  4
71111.05  Fire Plans        U2 PreFire Plan  Fire Zone 2B-ADD-DFV, Fire Area L (Diesel Fuel Vault)  4
71111.05  Fire Plans        U2 PreFire Plan  Fire Zone 2183-J, Fire Area B-3 (UNEPR)                17
71111.05  Fire Plans        U2 PreFire Plan  Fire Zone 75-AA, Fire Area B (CFW)                      17
71111.05  Fire Plans        U2 PreFire Plan  Fire Zone 2091-BB, Fire Area B-3 (North Electrical      17
Equipment Room)
71111.05  Miscellaneous                      Fire Hazards Analysis                                  19
71111.05  Miscellaneous    ASOTH-FP-        Pre-Drill Brief FBDRL 2021-05                          03/24/2021
FBDRLS, Att. 1
71111.05  Miscellaneous    ASOTH-FP-        Fire Brigade Drill Evaluation Worksheet                03/24/2021
FBDRLS, Att. 4
71111.05  Procedures        ASOTH-FP-        Instructors Guide for Fire Brigade Drills              9, 10
FBDRLS
71111.05  Procedures        EN-OP-125        Fire Brigade Drills                                    0
71111.05  Procedures        EN-TQ-125        Fire Brigade Drills                                    10
71111.05  Work Orders      WO              554636
71111.11Q  Corrective Action CR-ANO-          1-2011-01426, 1-2011-01439, 1-2011-01441, 2-2021-00149,
Documents
Inspection Type              Designation  Description or Title                                    Revision or
Procedure                                                                                          Date
71111.11Q  Miscellaneous    COLR-U2      Core Operating Limits Report for Cycle 28 (Unit 2)      28
71111.11Q  Procedures        OP-1102.004  Power Operation (Unit 1)                                76
71111.11Q  Procedures        OP-1102.016  Power Reduction and Plant Shutdown (Unit 1)              37
71111.11Q  Procedures        OP-1305.036  Unit 1 Power Range Linear Amp Calibration at Power      15
71111.11Q  Procedures        OP-2102.004  Power Operation (Unit 2)                                69
71111.13  Corrective Action CR-ANO-      1-2021-00263, 1-2021-00270, 1-2021-00300, 1-2021-00305,
Documents                      1-2021-00572
71111.13  Drawings          M204, Sheet 3 Emergency Feedwater                                      37
71111.13  Drawings          M204, Sheet 7 Common Feedwater System                                  3
71111.13  Miscellaneous                  Unit 1 Station Logs                                      02/14-
20/2021
71111.13  Miscellaneous                  Unit 2 Station Logs                                      01/22/2021
71111.13  Miscellaneous                  Unit 1 Station Logs                                      03/23/2021
71111.13  Procedures        1105.005      Emergency Feedwater Initiation and Control              48
71111.13  Procedures        1304.101      Unit 1 EFIC Channel D Calibration                        28
71111.13  Procedures        1304.208      Unit 1 EFIC Channel D Monthly Test                      28
71111.13  Procedures        EN-DC-151    PRA Maintenance and Update                              8
71111.13  Procedures        EN-OP-119    Protected Equipment Postings                            13
71111.13  Procedures        EN-WM-104    On Line Risk Assessment                                  22
71111.13  Work Orders      WO            557894-03
71111.15  Corrective Action CR-ANO-      1-2017-02434, 1-2020-02057, 1-2021-00201, 1-2021-00212,
Documents                      1-2021-00214, 1-2021-00290, 1-2021-00300, 1-2021-00308,
1-2021-00318, 1-2021-00319, 1-2021-00321, 1-2021-00442,
1-2021-00492, 1-2021-00562, C-2021-00539
71111.15  Drawings          M204, Sheet 3 Emergency Feedwater                                      37
71111.15  Drawings          M210, Sheet 1 Service Water                                            155
71111.15  Drawings          M236, Sheet 1 P&ID Reactor Building Spray and Core Flooding Systems    95
71111.15  Miscellaneous                  Unit 1 Station Logs                                      02/03/2021
71111.15  Miscellaneous    00-E-0023-01  Unit 1 Appendix J Containment Maximum Allowable          1
Leakage Rate (La)
71111.15  Procedures        1305.037      Unit 1 Reactor Building Access and Ventilation Leak Rate 12
Testing
71111.15  Procedures        EN-HU-106    Procedure and Work Instruction Use and Adherence        8
Inspection Type              Designation  Description or Title                                    Revision or
Procedure                                                                                          Date
71111.15  Procedures        OP-1104.002  Makeup and Purification System Operation                98
71111.15  Procedures        OP-1104.005  Reactor Building Spray System Operation                84
71111.15  Procedures        OP-1304.208  Unit 1 EFIC Channel D Monthly Test                    28
71111.15  Procedures        OP-3305.001  OPS System Alignment Tests                              2
71111.15  Work Orders      WO            557894, 5555551, 52918456-01,
71111.18  Corrective Action CR-ANO-      1-2011-01426, 1-2011-01439, 1-2011-01441
Documents
71111.18  Miscellaneous    95-R-105-08  Generic End-of-Cycle Full Power Life Extension Maneuver 09/13/2002
Report
71111.18  Miscellaneous    Cycle 29 COLR Unit One Core Operating Limits Report                  Cycle 29
71111.18  Miscellaneous    EC-78439      ANO-1 Cycle 29 Core Reload Evaluation                  10/17/2019
71111.18  Miscellaneous    EC-89320      ANO-1 End of Cycle 29 Tavg Reduction Maneuver          02/21/2021
71111.18  Miscellaneous    ER-ANO-2003-  ANO-1 End of Cycle Tavg Reduction Maneuver              06/30/2003
0488
71111.18  Procedures        OP-1102.004  Power Operations                                        76
71111.18  Work Orders      WO            52905418
71111.19  Corrective Action CR-ANO-      1-2021-00356, C-2021-00557
Documents
71111.19  Miscellaneous    EVAL 208820  Procurement Engineering Evaluation                      02/26/2021
71111.19  Procedures        OP-1104.032  Fire Protection Systems                                93
71111.19  Procedures        OP-1307.004  Diesel Fire Pump Engine (K-5) Biannual Surveillance    14
71111.19  Work Orders      WO            556999, 558192
71111.22  Calculations      CALC-V-2CV-  MOV Torque Switch Setpoints for 2CV-1002                10
1002
71111.22  Corrective Action CR-ANO-      1-2019-03844, 1-2019-00431, 1-2020-00962, 1-2020-01494,
Documents                      1-2020-01618, 1-2020-01687, 1-2020-01807, 1-2020-01971,
2-2021-00060, 2-2021-00074, 2-2021-00113, C-2021-
00103, C-2021-00110, C-2021-00176
71111.22  Engineering      EC-0088989    Replace Motor for MOV 2CV-1002                          0
Changes
71111.22  Procedures        EN-OP-104    Operability Determination Process                      16
71111.22  Procedures        OP-1104.029  Service Water and Auxiliary Cooling Water              121
71111.22  Procedures        OP-1104.036  Emergency Diesel Generator Operation                    85
Inspection Type              Designation Description or Title                                      Revision or
Procedure                                                                                          Date
71111.22  Procedures        OP-2104.037 Alternate AC Diesel Generator Operations                  35
71111.22  Procedures        OP-2105.008 Steam Dump Bypass Control System Operations                36
71111.22  Work Orders      WO          556225, 52915172, 52918456-01, 52923103
71114.01  Corrective Action CR-ANO-    1-2018-03990, 1-2018-04353, 1-2019-00231, 1-2019-04609,
Documents                    2-2018-01741, 2-2020-01204, 2-2020-02928, 2-2020-02972,
C-2018-02800, C-2018-02810, C-2020-02577, C-2020-
2641, C-2020-03417, C-2021-00101, C-2021-0833, C-
21-0835, C-2021-0836, C-2021-0837, C-2021-0841, C-
21-0843, C-2021-0844, C-2021-0845, C-2021-0846, C-
21-0847, C-2021-0848, C-2021-0849, C-2021-0850, C-
21-0852, C-2021-0854, C-2021-0855, C-2021-0873
71114.01  Corrective Action CR-ANO-    C-2021-00890, C-2021-00911
Documents
Resulting from
Inspection
71114.01  Miscellaneous                Arkansas Nuclear One, Yellow Team Site Drill Report,      09/19/2019
August 21, 2019
71114.01  Miscellaneous                Arkansas Nuclear One (ANO), ERO Team Yellow Site Drill    03/05/2020
Report, February 5, 2020
71114.01  Miscellaneous                ANO (Arkansas Nuclear One), ERO Green Team Site Drill      12/03/2020
Report, November 11, 2020
71114.01  Miscellaneous                Arkansas Nuclear One, Blue Team Site Drill Report, May 15, 06/12/2019
2019
71114.01  Miscellaneous                Arkansas Nuclear One, ERO Red Team Site Drill Report,      02/28/2019
February 6, 2019
71114.01  Procedures        1903.010    Emergency Action Level Classification                      57
71114.01  Procedures        1903.011    Emergency Response/Notifications                          57, 59
71114.01  Procedures        1903.069    Equipment Important to Emergency Response                  9, 10
71114.01  Procedures        1903.080    Emergency Operations Facility (EOF) Activation            4
71114.01  Procedures        1903.081    Technical Support Center (TSC) Activation                  0
71114.01  Procedures        1903.082    Operational Support Center (OSC) Activation                1
71114.01  Procedures        1905.001    Emergency Radiological Controls                            21
71114.01  Procedures        EN-EP-311  Emergency Response Data System (ERDS) Via the Virtual      4
Private Network (VPN)
Inspection Type              Designation Description or Title                                        Revision or
Procedure                                                                                            Date
71114.01  Procedures        EN-EP-609  Emergency Operations Facility (EOF) Operations              6
71114.01  Procedures        EN-EP-610  Technical Support Center (TSC) Operations                    5
71114.01  Procedures        EN-EP-611  Operations Support Center (OSC) Operations                  6
71114.04  Miscellaneous                Attachment 2, 10 CFR 50.54(q)(3) Screening,                  11/10/2020
Procedure/Document Number: ANO Emergency Plan,
Revision: 046
71114.04  Miscellaneous                Attachment 3, 10 CFR 50.54(q)(3) Evaluation;                11/20/2020
Procedure/Document Number: ANO Emergency Plan;
Revision: 046
71114.04  Miscellaneous    0CAN122002  Emergency Plan and Emergency Plan Implementing              12/02/2020
Procedure, Arkansas Nuclear One, Units 1 and 2; NRC
Docket Nos. 50-313, 50-368, and 72-13; Renewed Facility
Operating License Nos. DPR-51 and NPF-6
71114.06  Corrective Action CR-ANO-    C-2021-00670, C-2021-00686
Documents
71114.06  Miscellaneous                2021 Emergency Preparedness Scenario 21DR                    02/16/2021
71114.08  Miscellaneous    0CAN012102  Emergency Plan Full Participation - Exercise Drill Scenario; 01/20/2021
Arkansas Nuclear One, Units 1 and 2; NRC Docket Nos. 50-
313, 50-368, and 72-13; Renewed Facility Operating License
Nos. DPR-51 and NPF-6
71114.08  Procedures        1903.010    Emergency Action Level Classification                        59
71114.08  Procedures        1903.011    Emergency Response/Notifications                            57
71151      Corrective Action CR-ANO-    1-2020-00547, 2-2020-02252, 2-2020-02381, 2-2020-03840,
Documents                    2-2021-00243
71151      Miscellaneous                Unit 2 Plant Data Server Power Trend                        03/13/2020
71151      Miscellaneous                ANO-1 and ANO-2 NRC Performance Indicator                    Q1-2020
Technique/Data Sheets - Initiating Events
71151      Miscellaneous                ANO-1 and ANO-2 NRC Performance Indicator                    Q2-2020
Technique/Data Sheets - Initiating Events
71151      Miscellaneous                ANO-1 and ANO-2 NRC Performance Indicator                    Q3-2020
Technique/Data Sheets - Initiating Events
71151      Miscellaneous                ANO-1 and ANO-2 NRC Performance Indicator                    Q4-2020
Technique/Data Sheets - Initiating Events
71151      Miscellaneous                Unit 2 Station Log                                          11/01/2020
Inspection Type              Designation  Description or Title                                      Revision or
Procedure                                                                                            Date
71151      Miscellaneous                  Unit 2 Station Log                                        12/10/2020
71151      Miscellaneous                  Drill and Exercise Performance (DEP) Performance Indicator 07/2020 -
                                          (PI) Monthly Reports                                      12/2020
71151      Miscellaneous                  Select DEP PI Opportunity Assessment Packages (3Q/2020    07/2020 -
                                          - 4Q/2020)                                                12/2020
71151      Miscellaneous                  ANO Emergency Response Organization Rosters (3Q/2020      09/30/2020,
                                          - 4Q/2020)                                                12/31/2020
71151      Miscellaneous                  ANO ERO Qualification Records (3Q/2020 - 4Q/2020)          09/30/2020,
2/31/2020
71151      Miscellaneous                  ADH Siren Verification Checklists (3Q/2020 and 4Q/2020)    07/2020 -
2/2020
71151      Miscellaneous    KLD TR -1208  ANO Alert and Notification System (ANS) Design Report      09/25/2020
                                          (Rev. 4)
71151      Procedures        EN-FAP-EP-005 Emergency Preparedness Performance Indicators              14
71151      Procedures        EN-LI-114    Regulatory Performance Indicator Process                  17
71151      Procedures        OP-2203.053  Rapid Power Reduction                                      7
71153      Corrective Action CR-ANO-      1-2021-00457
Documents
71153      Drawings          E1, Sheet 1  Station Single Line Diagram                                63
71153      Drawings          M231, Sheet 2 Makeup & Purification System                              51
71153      Miscellaneous                  Unit 1 Station Logs                                        03/14/2021
71153      Miscellaneous                  Unit 1 Emergency Action Levels                            0
71153      Procedures        OP-1202.001  Reactor Trip                                              40
71153      Procedures        OP-1203.012I  Annunciator K10 Corrective Action                          62
71153      Procedures        OP-1203.019  High Activity in Reactor Coolant                          19
71153      Procedures        OP-1416.002  U1 A2 Bus Switchgear Inspection                            21
16
}}
}}

Revision as of 09:49, 9 September 2021

Integrated Inspection Report 05000313/2021001 and 05000368/2021001
ML21126A170
Person / Time
Site: Arkansas Nuclear  Entergy icon.png
Issue date: 05/06/2021
From: John Dixon
NRC/RGN-IV/DRP/RPB-D
To: Dinelli J
Entergy Operations
References
IR 2021001
Download: ML21126A170 (19)


Text

May 06, 2021

SUBJECT:

ARKANSAS NUCLEAR ONE - INTEGRATED INSPECTION REPORT 05000313/2021001 AND 05000368/2021001

Dear Mr. Dinelli:

On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Arkansas Nuclear One. On April 8, 2021, the NRC inspectors discussed the results of this inspection with Mr. J. Sullivan, General Manager Plant Operations, 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.

If you disagree with 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 Arkansas Nuclear One. 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, John L. Digitally signed by John L. Dixon Dixon Date: 2021.05.06 15:05:13 -05'00'

John L. Dixon, Jr., Chief Reactor Projects Branch D Division of Reactor Projects Docket Nos. 05000313 and 05000368 License Nos. DPR-51 and NPF-6

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000313 and 05000368 License Numbers: DPR-51 and NPF-6 Report Numbers: 05000313/2021001 and 05000368/2021001 Enterprise Identifier: I-2021-001-0050 Licensee: Entergy Operations, Inc.

Facility: Arkansas Nuclear One Location: Russellville, AR Inspection Dates: January 1, 2021 to March 31, 2021 Inspectors: R. Alexander, Senior Emergency Preparedness Inspector N. Brown, Resident Inspector R. Bywater, Senior Resident Inspector T. DeBey, Resident Inspector H. Freeman, Senior Project Engineer S. Hedger, Emergency Preparedness Inspector Approved By: John L. Dixon, Jr., Chief Reactor Projects Branch D Division of Reactor Projects Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Arkansas Nuclear One, 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

Unit 2 Trip Due to Failure to Evaluate/Classify a Feedwater Control System Power Supply Component as Critical Equipment Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green None 71153 FIN 05000368/2021001-01 Open/Closed The inspectors identified a Green finding for the licensees failure to properly evaluate and classify the Unit 2 main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000368/2020-001-00 Loss of Feedwater Control 71153 Closed System Power for Train 'A'

Feedwater that Resulted in Plant Trip

PLANT STATUS

Unit 1 began the inspection period at full power. On February 15, 2021, Unit 1 operators reduced power to 32 percent power at request of the grid operator to reduce station output.

Operators returned the unit to full power on February 18, 2021.

On March 14, 2021, Unit 1 was manually tripped from 99 percent power after a loss of voltage on bus A2 resulting from a continuity failure in a related potential transformer drawer. After repairs, operators restarted the reactor on March 17, placed the unit online on March 18, and raised power to 95 percent on March 21, 2021.

Unit 1 began an end-of-operating cycle power coastdown on March 29, 2021 and ended the inspection period at approximately 90 percent power.

Unit 2 began the inspection period at full power and remained at full power until January 10, 2021, when operators reduced power to 77 percent power to address a main feedwater pump B speed oscillation issue. After repairs, operators returned the unit to 90 percent power on January 12, 2021.

On January 13, 2021, Unit 2 operators reduced power to 86 percent power to complete repairs to address elevated condenser air in-leakage. After repairs, operators returned the unit to full power on January 14, 2021.

On January 26, 2021, Unit 2 operators performed a planned power reduction to 81 percent power to replace a backup power supply for the core operating limits supervisory system and perform main turbine control valve testing. Operators returned the unit to full power the same day without replacing the power supply after determining the observed core power distribution did not support removing the core operating limits supervisory system from service at the planned reduced power level.

On February 15, 2021, Unit 2 operators reduced power to 88 percent power at the request of the grid operator to reduce station output. Operators returned the unit to full power on February 17, 2021.

On March 4, 2021, Unit 2 operators reduced power to 65 percent power to replace the core operating limits supervisory system backup power supply. After completion of repairs, operators returned to unit to full power later that day and the unit remained at full 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 Disease 2019 (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; conducted plant status activities as described in IMC 2515, Appendix D, Plant Status; 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 portions 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

71111.04 - 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) Unit 1 decay heat removal/low-pressure injection train B during maintenance on train A on January 7, 2021
(2) Unit 2 FLEX reactor coolant/steam generator pump placement on March 23, 2021
(3) Unit 2 containment spray train A during maintenance on loop 1 service water to containment cooler service water isolation valve maintenance on March 30, 2021
(4) Unit 2 motor-driven emergency feedwater train during turbine-driven emergency feedwater train flow transmitter maintenance on March 11, 2021

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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) Unit 1 steam pipe room, Fire Zone 170-Z, on January 6, 2021
(2) Unit 2 upper north electrical penetration room, Fire Zone 2183-J, on January 20, 2021
(3) Unit 1 common feedwater pump room, Fire Zone 75-AA, on January 21, 2021
(4) Common unit diesel fuel vaults, Fire Zone 1(2)B-ADD-DFV, on March 3, 2021

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the onsite fire brigade training and performance during an unannounced fire drill on March 24, 2021.

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 a Unit 2 planned down power to 65 percent and a subsequent power increase on March 4, 2021.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated Unit 1 just-in-time training that was done in preparation for the unit operation at reduced Tavg on March 10, 2021.

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) Unit 2 emergent work activities for the atmospheric dump valve isolation valve 2CV-1002 failure to stroke due to motor failure on January 22, 2021
(2) Unit 1 emergent work activities for the emergency feedwater initiation and control Channel B failure due to freezing steam generator pressure sensing lines on February 15, 2021
(3) Unit 1 emergent work activities for the emergency feedwater initiation and control Channel D failure due to power supply failure on February 19, 2021
(4) Unit 1 common feedwater injection to steam generator B valve CV-2660B maintenance on March 23, 2021

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) Unit 1 operability determination for reactor building spray system after seat leakage through recirculation and test header isolation valve BS-2B was discovered during surveillance testing on February 3, 2021
(2) Unit 1 operability determination for reactor building spray pump B suction pressure transmitter PT-2428 on February 5, 2021
(3) Unit 1 operability determination for high-pressure injection pump P-36B on February 10, 2021
(4) Unit 1 operability determination for emergency feedwater initiation and control channel B on February 19-22, 2021
(5) Unit 1 operability determination for Unit 1 personnel airlock inner door seal on March 11, 2021
(6) Unit 1 operability determination for service water pipe leak upstream of valve CV-3850, service water loop 1 to emergency feedwater supply valve on March 17, 2021

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) ANO-1 End of Cycle 29 Tavg Reduction Maneuver on March 11-17, 2021

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (1 Sample)

The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:

(1) Common unit diesel-driven fire pump P-6B post-maintenance testing after engine failure and replacement of starter motor on February 27, 2021

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

(1) Unit 2 valve stroke surveillance for atmospheric dump isolation valve 2CV-1002 on January 26, 2021
(2) Unit 1 valve stroke surveillance for service water sluice gates on February 3, 2021
(3) Unit 1 emergency diesel generator 1 monthly surveillance run on February 7, 2021
(4) Alternate ac diesel generator quarterly run on February 9, 2021

71114.01 - Exercise Evaluation

Inspection Review (IP Section 02.01-02.11) (1 Sample)

(1) The inspectors evaluated the biennial emergency plan exercise conducted on March 23, 2021. The exercise scenario simulated a reactor coolant pump malfunction causing fuel damage, a steam generator tube rupture associated with a stuck open safety-relief valve, and demonstrations of extensive damage mitigation strategies consistent with 10 CFR 50.155(b)(2).

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.01-02.03) (1 Sample)

(1) The licensee submitted a summary of emergency plan changes (Revision 46) to the NRC on December 2, 2020. The inspectors conducted a review of the changes from March 1 to March 31, 2021. 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) The inspectors evaluated an emergency planning drill involving a tornado event which damaged plant equipment on March 9, 2021.

71114.08 - Exercise Evaluation Scenario Review

Inspection Review (IP Section 02.01 - 02.04) (1 Sample)

(1) The inspectors reviewed and evaluated the proposed scenario for the biennial emergency plan exercise on March 23,

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

EP01: Drill/Exercise Performance (IP Section 03.12) ===

(1) Units 1 and 2 (July 1, 2020 through December 31, 2020)

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 03.01) (2 Samples)

(1) Unit 1 (January 1, 2020 through December 31, 2020)
(2) Unit 2 (January 1, 2020 through December 31, 2020)

EP02: ERO Drill Participation (IP Section 03.13) (1 Sample)

(1) Units 1 and 2 (July 1, 2020, through December 31, 2020)

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02)

(2 Samples)

(1) Unit 1 (January 1, 2020 through December 31, 2020)
(2) Unit 2 (January 1, 2020 through December 31, 2020)

EP03: Alert & Notification System Reliability (IP Section 03.14) (1 Sample)

(1) Units 1 and 2 (July 1, 2020 through December 31, 2020)

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 03.03) (2 Samples)

(1) Unit 1 (January 1, 2020 through December 31, 2020)
(2) Unit 2 (January 1, 2020 through December 31, 2020)

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 05000368/2020-001-00, Loss of Feedwater Control System Power for Train A Feedwater that Resulted in Plant Trip (ADAMS Accession No. ML21039A557). The inspection conclusions associated with this LER are documented in this report as Finding 05000368/2021001-01.

INSPECTION RESULTS

Unit 2 Trip Due to Failure to Evaluate/Classify a Feedwater Control System Power Supply Component as Critical Equipment Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green None 71153 FIN 05000368/2021001-01 Open/Closed The inspectors identified a Green finding for the licensees failure to properly evaluate and classify the Unit 2 main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.

Description:

On December 10, 2020, while operating at full power, the ANO Unit 2 reactor experienced a loss of main feedwater flow through the A main feedwater train due to a complete loss of A main feedwater control system electrical power. That power loss prevented the expected system response and associated alarms and indications for a loss of main feedwater train from occurring. The A main feedwater pump turbine went to minimum speed, the A main feedwater control valve shut, and manual control of the A main feedwater train was not possible. While the licensed operators recognized there was a problem with the main feedwater system, the reactor automatically tripped on A low steam generator water level before they could take any action. Post-trip investigation showed that the A main feedwater control system had experienced a complete loss of power even though it had redundant power supplies. The failure of one power supply should not cause complete loss of system power. Initial troubleshooting did not identify the cause of the event. After cycling the input power switches to the power supplies, both supplies came on and provided voltage outputs that were within specifications. Some components of the individual power supplies in the A main feedwater control system were replaced (although they were not failed) and the reactor was returned to power.

The inspectors independently reviewed the event and questioned the licensee whether there was a downstream electrolytic capacitor that could have caused the loss of power. The licensee evaluated that potential and concluded that a capacitor in a filter assembly downstream of the redundant power supplies was the likely cause of the event. Since a functional failure of a capacitor in the filter assembly would cause a complete loss of power to the main feedwater control system, it would cause a plant trip. That vulnerability should have led to the capacitor filter assembly having been classified as a critical component in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21, Section 5.2, Step 4. Components classified as critical shall be included in the PM [preventive maintenance] program and have a Maintenance Strategy developed in accordance with Procedure EN-DC-335. Since the downstream filter capacitors had not been classified, there was no preventive maintenance strategy for them. In fact, the licensee could not find any evidence that any maintenance had ever been performed. That resulted in electrolytic capacitors that were more than 25 years old being in the system. Per the sites Operational Decision Making document for this event, the electrolytic capacitors should have changed out per our SPV [single point vulnerability] PM fleet strategy on a 6 year interval.

The engineering review for the power supply installation in 1995 failed to identify the vulnerability.

Corrective Actions: The A train main feedwater control system power supplies for Unit 2 were reset and preventive maintenance activities were performed. A voltage monitor was set up to provide detailed data for future analysis of any similar future events. An apparent cause analysis was performed, and classification reviews of other redundant power supply systems are being performed. The site has classified the filter assemblies as single point vulnerabilities per Procedure EN-DC-175 but the critical equipment classification has not yet been completed. Future activities are being planned to redesign the main feedwater control system power supplies so that the common filter assembly is removed. The licensee submitted Licensee Event Report LER 05000368/2020-001-00.

Corrective Action References: Condition Report CR-ANO-2-2020-03843 and associated Apparent Causal Analysis CR-ANO-2-2020-03913

Performance Assessment:

Performance Deficiency: The licensees failure to properly evaluate and classify the main feedwater control system power supply common filter assembly as critical equipment in accordance with Procedure EN-DC-153, Preventive Maintenance Component Classification, Revision 21, was a performance deficiency. Specifically, the failure to identify the power supply common filter assembly as a critical component with a single point vulnerability led to the failure to perform preventive maintenance, mitigate, or remove the vulnerability, whose failure was the likely cause of the automatic reactor trip on December 10, 2020.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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 unrecognized single point vulnerability of the power supply filter assembly led to the vulnerability not being mitigated and caused a complete loss of electrical power to the A main feedwater control system that resulted in a plant trip.

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 had very low safety significance (Green) because the finding did not cause a reactor trip AND the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition.

Cross-Cutting Aspect: None. The original equipment classification error occurred when the power supplies were installed in 1995 and an additional missed opportunity to identify the issue occurred in 2015 when the system was reviewed during a site-wide Component Criticality Validation Sample Review was done as part of the ANO Comprehensive Recovery Plan. This missed opportunity was not considered to be reflective of present licensee performance.

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 February 18, 2021, the inspectors presented the emergency exercise preliminary scenario review inspection results to Mr. J. Toben, Manager, Emergency Preparedness, and other members of the licensee staff.
  • On April 8, 2021, the inspectors presented the emergency preparedness exercise inspection results to Mr. J. Sullivan, General Manager Plant Operations, and other members of the licensee staff.
  • On April 8, 2021, the inspectors presented the integrated inspection results to Mr. J. Sullivan, General Manager Plant Operations, and other members of the licensee staff.

THIRD PARTY REVIEWS The inspectors reviewed a World Association of Nuclear Operators report during the inspection period.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.04 Corrective Action CR-ANO- 1-2020-00824, 1-2020-01378, 1-2020-01509, 1-2020-01678,

Documents 1-2020-01945, 2-2021-00464

71111.04 Drawings M2210, Sheet 3 Service Water System 92

71111.04 Drawings M2236, Sheet 1 Containment Spray System 96

71111.04 Procedures OP-1104.004 Decay Heat Removal Operating Procedure 132

OP-2106.006 Emergency Feedwater System Operations 104

71111.04 Work Orders WO 52894842, 52911085

71111.05 Corrective Action CR-ANO- 1-2021-00031, 1-2021-00345, 2-2020-03887, 2-2021-00142,

Documents 2-2021-00521, C-2020-02793, C-2021-00858

71111.05 Drawings FP-109 Fire Zones Emergency Diesel Fuel Storage Vault 8

71111.05 Drawings FP-2103 El 368-0 and 372-0 38

71111.05 Drawings FP-2103, Sheet 1 El 368-0 and 372-0 38

71111.05 Drawings FP-2111 Fire Zones Emergency Diesel Fuel Storage Vault 8

71111.05 Drawings FZ-2027 Fire Zone Electrical Equipment Room 4

71111.05 Fire Plans U1 PreFire Plan Fire Zone 1B-ADD-DFV, Fire Area L (Diesel Fuel Vault) 4

71111.05 Fire Plans U2 PreFire Plan Fire Zone 2B-ADD-DFV, Fire Area L (Diesel Fuel Vault) 4

71111.05 Fire Plans U2 PreFire Plan Fire Zone 2183-J, Fire Area B-3 (UNEPR) 17

71111.05 Fire Plans U2 PreFire Plan Fire Zone 75-AA, Fire Area B (CFW) 17

71111.05 Fire Plans U2 PreFire Plan Fire Zone 2091-BB, Fire Area B-3 (North Electrical 17

Equipment Room)

71111.05 Miscellaneous Fire Hazards Analysis 19

71111.05 Miscellaneous ASOTH-FP- Pre-Drill Brief FBDRL 2021-05 03/24/2021

FBDRLS, Att. 1

71111.05 Miscellaneous ASOTH-FP- Fire Brigade Drill Evaluation Worksheet 03/24/2021

FBDRLS, Att. 4

71111.05 Procedures ASOTH-FP- Instructors Guide for Fire Brigade Drills 9, 10

FBDRLS

71111.05 Procedures EN-OP-125 Fire Brigade Drills 0

71111.05 Procedures EN-TQ-125 Fire Brigade Drills 10

71111.05 Work Orders WO 554636

71111.11Q Corrective Action CR-ANO- 1-2011-01426, 1-2011-01439, 1-2011-01441, 2-2021-00149,

Documents

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.11Q Miscellaneous COLR-U2 Core Operating Limits Report for Cycle 28 (Unit 2) 28

71111.11Q Procedures OP-1102.004 Power Operation (Unit 1) 76

71111.11Q Procedures OP-1102.016 Power Reduction and Plant Shutdown (Unit 1) 37

71111.11Q Procedures OP-1305.036 Unit 1 Power Range Linear Amp Calibration at Power 15

71111.11Q Procedures OP-2102.004 Power Operation (Unit 2) 69

71111.13 Corrective Action CR-ANO- 1-2021-00263, 1-2021-00270, 1-2021-00300, 1-2021-00305,

Documents 1-2021-00572

71111.13 Drawings M204, Sheet 3 Emergency Feedwater 37

71111.13 Drawings M204, Sheet 7 Common Feedwater System 3

71111.13 Miscellaneous Unit 1 Station Logs 02/14-

20/2021

71111.13 Miscellaneous Unit 2 Station Logs 01/22/2021

71111.13 Miscellaneous Unit 1 Station Logs 03/23/2021

71111.13 Procedures 1105.005 Emergency Feedwater Initiation and Control 48

71111.13 Procedures 1304.101 Unit 1 EFIC Channel D Calibration 28

71111.13 Procedures 1304.208 Unit 1 EFIC Channel D Monthly Test 28

71111.13 Procedures EN-DC-151 PRA Maintenance and Update 8

71111.13 Procedures EN-OP-119 Protected Equipment Postings 13

71111.13 Procedures EN-WM-104 On Line Risk Assessment 22

71111.13 Work Orders WO 557894-03

71111.15 Corrective Action CR-ANO- 1-2017-02434, 1-2020-02057, 1-2021-00201, 1-2021-00212,

Documents 1-2021-00214, 1-2021-00290, 1-2021-00300, 1-2021-00308,

1-2021-00318, 1-2021-00319, 1-2021-00321, 1-2021-00442,

1-2021-00492, 1-2021-00562, C-2021-00539

71111.15 Drawings M204, Sheet 3 Emergency Feedwater 37

71111.15 Drawings M210, Sheet 1 Service Water 155

71111.15 Drawings M236, Sheet 1 P&ID Reactor Building Spray and Core Flooding Systems 95

71111.15 Miscellaneous Unit 1 Station Logs 02/03/2021

71111.15 Miscellaneous 00-E-0023-01 Unit 1 Appendix J Containment Maximum Allowable 1

Leakage Rate (La)

71111.15 Procedures 1305.037 Unit 1 Reactor Building Access and Ventilation Leak Rate 12

Testing

71111.15 Procedures EN-HU-106 Procedure and Work Instruction Use and Adherence 8

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.15 Procedures OP-1104.002 Makeup and Purification System Operation 98

71111.15 Procedures OP-1104.005 Reactor Building Spray System Operation 84

71111.15 Procedures OP-1304.208 Unit 1 EFIC Channel D Monthly Test 28

71111.15 Procedures OP-3305.001 OPS System Alignment Tests 2

71111.15 Work Orders WO 557894, 5555551, 52918456-01,

71111.18 Corrective Action CR-ANO- 1-2011-01426, 1-2011-01439, 1-2011-01441

Documents

71111.18 Miscellaneous 95-R-105-08 Generic End-of-Cycle Full Power Life Extension Maneuver 09/13/2002

Report

71111.18 Miscellaneous Cycle 29 COLR Unit One Core Operating Limits Report Cycle 29

71111.18 Miscellaneous EC-78439 ANO-1 Cycle 29 Core Reload Evaluation 10/17/2019

71111.18 Miscellaneous EC-89320 ANO-1 End of Cycle 29 Tavg Reduction Maneuver 02/21/2021

71111.18 Miscellaneous ER-ANO-2003- ANO-1 End of Cycle Tavg Reduction Maneuver 06/30/2003

0488

71111.18 Procedures OP-1102.004 Power Operations 76

71111.18 Work Orders WO 52905418

71111.19 Corrective Action CR-ANO- 1-2021-00356, C-2021-00557

Documents

71111.19 Miscellaneous EVAL 208820 Procurement Engineering Evaluation 02/26/2021

71111.19 Procedures OP-1104.032 Fire Protection Systems 93

71111.19 Procedures OP-1307.004 Diesel Fire Pump Engine (K-5) Biannual Surveillance 14

71111.19 Work Orders WO 556999, 558192

71111.22 Calculations CALC-V-2CV- MOV Torque Switch Setpoints for 2CV-1002 10

1002

71111.22 Corrective Action CR-ANO- 1-2019-03844, 1-2019-00431, 1-2020-00962, 1-2020-01494,

Documents 1-2020-01618, 1-2020-01687, 1-2020-01807, 1-2020-01971,

2-2021-00060, 2-2021-00074, 2-2021-00113, C-2021-

00103, C-2021-00110, C-2021-00176

71111.22 Engineering EC-0088989 Replace Motor for MOV 2CV-1002 0

Changes

71111.22 Procedures EN-OP-104 Operability Determination Process 16

71111.22 Procedures OP-1104.029 Service Water and Auxiliary Cooling Water 121

71111.22 Procedures OP-1104.036 Emergency Diesel Generator Operation 85

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.22 Procedures OP-2104.037 Alternate AC Diesel Generator Operations 35

71111.22 Procedures OP-2105.008 Steam Dump Bypass Control System Operations 36

71111.22 Work Orders WO 556225, 52915172, 52918456-01, 52923103

71114.01 Corrective Action CR-ANO- 1-2018-03990, 1-2018-04353, 1-2019-00231, 1-2019-04609,

Documents 2-2018-01741, 2-2020-01204, 2-2020-02928, 2-2020-02972,

C-2018-02800, C-2018-02810, C-2020-02577, C-2020-

2641, C-2020-03417, C-2021-00101, C-2021-0833, C-

21-0835, C-2021-0836, C-2021-0837, C-2021-0841, C-

21-0843, C-2021-0844, C-2021-0845, C-2021-0846, C-

21-0847, C-2021-0848, C-2021-0849, C-2021-0850, C-

21-0852, C-2021-0854, C-2021-0855, C-2021-0873

71114.01 Corrective Action CR-ANO- C-2021-00890, C-2021-00911

Documents

Resulting from

Inspection

71114.01 Miscellaneous Arkansas Nuclear One, Yellow Team Site Drill Report, 09/19/2019

August 21, 2019

71114.01 Miscellaneous Arkansas Nuclear One (ANO), ERO Team Yellow Site Drill 03/05/2020

Report, February 5, 2020

71114.01 Miscellaneous ANO (Arkansas Nuclear One), ERO Green Team Site Drill 12/03/2020

Report, November 11, 2020

71114.01 Miscellaneous Arkansas Nuclear One, Blue Team Site Drill Report, May 15, 06/12/2019

2019

71114.01 Miscellaneous Arkansas Nuclear One, ERO Red Team Site Drill Report, 02/28/2019

February 6, 2019

71114.01 Procedures 1903.010 Emergency Action Level Classification 57

71114.01 Procedures 1903.011 Emergency Response/Notifications 57, 59

71114.01 Procedures 1903.069 Equipment Important to Emergency Response 9, 10

71114.01 Procedures 1903.080 Emergency Operations Facility (EOF) Activation 4

71114.01 Procedures 1903.081 Technical Support Center (TSC) Activation 0

71114.01 Procedures 1903.082 Operational Support Center (OSC) Activation 1

71114.01 Procedures 1905.001 Emergency Radiological Controls 21

71114.01 Procedures EN-EP-311 Emergency Response Data System (ERDS) Via the Virtual 4

Private Network (VPN)

Inspection Type Designation Description or Title Revision or

Procedure Date

71114.01 Procedures EN-EP-609 Emergency Operations Facility (EOF) Operations 6

71114.01 Procedures EN-EP-610 Technical Support Center (TSC) Operations 5

71114.01 Procedures EN-EP-611 Operations Support Center (OSC) Operations 6

71114.04 Miscellaneous Attachment 2, 10 CFR 50.54(q)(3) Screening, 11/10/2020

Procedure/Document Number: ANO Emergency Plan,

Revision: 046

71114.04 Miscellaneous Attachment 3, 10 CFR 50.54(q)(3) Evaluation; 11/20/2020

Procedure/Document Number: ANO Emergency Plan;

Revision: 046

71114.04 Miscellaneous 0CAN122002 Emergency Plan and Emergency Plan Implementing 12/02/2020

Procedure, Arkansas Nuclear One, Units 1 and 2; NRC

Docket Nos. 50-313, 50-368, and 72-13; Renewed Facility

Operating License Nos. DPR-51 and NPF-6

71114.06 Corrective Action CR-ANO- C-2021-00670, C-2021-00686

Documents

71114.06 Miscellaneous 2021 Emergency Preparedness Scenario 21DR 02/16/2021

71114.08 Miscellaneous 0CAN012102 Emergency Plan Full Participation - Exercise Drill Scenario; 01/20/2021

Arkansas Nuclear One, Units 1 and 2; NRC Docket Nos. 50-

313, 50-368, and 72-13; Renewed Facility Operating License

Nos. DPR-51 and NPF-6

71114.08 Procedures 1903.010 Emergency Action Level Classification 59

71114.08 Procedures 1903.011 Emergency Response/Notifications 57

71151 Corrective Action CR-ANO- 1-2020-00547, 2-2020-02252, 2-2020-02381, 2-2020-03840,

Documents 2-2021-00243

71151 Miscellaneous Unit 2 Plant Data Server Power Trend 03/13/2020

71151 Miscellaneous ANO-1 and ANO-2 NRC Performance Indicator Q1-2020

Technique/Data Sheets - Initiating Events

71151 Miscellaneous ANO-1 and ANO-2 NRC Performance Indicator Q2-2020

Technique/Data Sheets - Initiating Events

71151 Miscellaneous ANO-1 and ANO-2 NRC Performance Indicator Q3-2020

Technique/Data Sheets - Initiating Events

71151 Miscellaneous ANO-1 and ANO-2 NRC Performance Indicator Q4-2020

Technique/Data Sheets - Initiating Events

71151 Miscellaneous Unit 2 Station Log 11/01/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

71151 Miscellaneous Unit 2 Station Log 12/10/2020

71151 Miscellaneous Drill and Exercise Performance (DEP) Performance Indicator 07/2020 -

(PI) Monthly Reports 12/2020

71151 Miscellaneous Select DEP PI Opportunity Assessment Packages (3Q/2020 07/2020 -

- 4Q/2020) 12/2020

71151 Miscellaneous ANO Emergency Response Organization Rosters (3Q/2020 09/30/2020,

- 4Q/2020) 12/31/2020

71151 Miscellaneous ANO ERO Qualification Records (3Q/2020 - 4Q/2020) 09/30/2020,

2/31/2020

71151 Miscellaneous ADH Siren Verification Checklists (3Q/2020 and 4Q/2020) 07/2020 -

2/2020

71151 Miscellaneous KLD TR -1208 ANO Alert and Notification System (ANS) Design Report 09/25/2020

(Rev. 4)

71151 Procedures EN-FAP-EP-005 Emergency Preparedness Performance Indicators 14

71151 Procedures EN-LI-114 Regulatory Performance Indicator Process 17

71151 Procedures OP-2203.053 Rapid Power Reduction 7

71153 Corrective Action CR-ANO- 1-2021-00457

Documents

71153 Drawings E1, Sheet 1 Station Single Line Diagram 63

71153 Drawings M231, Sheet 2 Makeup & Purification System 51

71153 Miscellaneous Unit 1 Station Logs 03/14/2021

71153 Miscellaneous Unit 1 Emergency Action Levels 0

71153 Procedures OP-1202.001 Reactor Trip 40

71153 Procedures OP-1203.012I Annunciator K10 Corrective Action 62

71153 Procedures OP-1203.019 High Activity in Reactor Coolant 19

71153 Procedures OP-1416.002 U1 A2 Bus Switchgear Inspection 21

16