ML23318A458
| ML23318A458 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 11/14/2023 |
| From: | Bradley Davis NRC/RGN-II/DCI |
| To: | Coleman J Southern Nuclear Operating Co |
| References | |
| IR 2023003 | |
| Download: ML23318A458 (1) | |
Text
Jamie Coleman Director, Fleet Regulatory Affairs Southern Nuclear Operating Company, Inc.
3535 Colonnade Parkway, BIN 63031 Birmingham, AL 35243
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNIT 3 - INTEGRATED INSPECTION REPORT 05200025/2023003
Dear Jamie Coleman:
On September 30, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Vogtle Electric Generating Plant (VEGP), Unit 3. On October 24, 2023, the NRC inspectors discussed the results of this inspection with Mr. Glen Chick, VEGP Units 3 & 4 Executive Vice President and other members of your staff. The results of this inspection are documented in the enclosed report.
Two findings of very low safety significance (Green) are documented in this report. None of these findings involved 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 II; the Director, Office of Enforcement; and the NRC Resident Inspector at Vogtle Electric Generating Plant, Unit 3.
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 II; and the NRC Resident Inspector at Vogtle Electric Generating Plant, Unit 3.
November 14, 2023
J. Coleman 2
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, Bradley J. Davis, Chief Construction Inspection Branch 2 Division of Construction Oversight Docket No. 05200025 License No. NPF-91
Enclosure:
As stated cc w/ encl: Distribution via LISTSERV Signed by Davis, Bradley on 11/14/23
SUNSI Review x
Non-Sensitive
Sensitive x
Publicly Available
Non-Publicly Available OFFICE RII: DCO RII: DCO RII: DCO NAME B. Kemker C. Even B. Davis DATE 11/14/2023 11/09/2023 11/14/2023
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Inspection Report Docket Number:
05200025 License Number:
NPF-91 Report Number:
05200025/2023003 Enterprise Identifier:
I-2023-003-0063 Licensee:
Southern Nuclear Operating Company, Inc.
Facility:
Vogtle Electric Generating Plant, Unit 3 Location:
Waynesboro, GA Inspection Dates:
July 01, 2023, to September 30, 2023 Inspectors:
B. Kemker, Senior Resident Inspector J. Eargle, Senior Resident Inspector B. Griman, Resident Inspector J. Parent, Resident Inspector J. England, Sr. Construction Inspector S. Egli, Sr. Construction Inspector J. Bell, Senior Health Physicist J. Diaz-Velez, Senior Health Physicist A. Nielsen, Senior Health Physicist J. Rivera, Health Physicist Approved By:
Bradley J. Davis, Chief Construction Inspection Branch 2 Division of Construction Oversight
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Vogtle Electric Generating Plant, Unit 3, 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: 71124.05.
List of Findings and Violations Failure to Adequately Implement Severe Weather Procedure NMP-OS-017 Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05200025/2023003-01 Open/Closed
[H.4] -
Teamwork 71111.01 The inspectors identified a Green finding of very low safety significance for the licensees failure to implement procedure NMP-OS-017, Severe Weather, Version 3.1, by failing to remove or secure equipment that could become a missile due to severe weather affecting the plant site.
Failure to Remove Manufacturer Shipping Flanges from the Main Condenser A and C Flashbox Nozzles Results in Turbine/Reactor Trips Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05200025/2023003-02 Open/Closed
[H.1] -
Resources 71153 A Green finding of very low safety significance was self-revealed from a manual turbine trip and manual reactor trip during plant startup testing. The licensee failed to remove manufacturer shipping flanges from the main condenser A and C flashbox nozzles, as specified on the installation drawing, which led to the event.
Additional Tracking Items Type Issue Number Title Report Section Status URI 05200025/2023002-01 Maintenance Rule Evaluations for Plant Level Events 71111.12 Closed LER 05200025/2023-004-00 LER 2023-004-00 for Vogtle Electric Generating Plant, Unit 3, Manual Reactor Protection System Actuation Due to Condenser Flanges Not Removed During Construction 71153 Closed
3 LER 05200025/2023-005-00 LER 2023-005-00 for Vogtle Electric Generating Plant (VEGP), Unit 3, Automatic Reactor Protection System Actuation During Startup Testing Due to Inadequate Turbine Trip Logic 71153 Closed NOV 05200025/2022-011-01 Failure to Follow Procedure for Unit 3 Hot Functional Testing 92702 Closed NOV 05200025/2022-011-02 Failure to Maintain Complete and Accurate Test Records for Unit 3 Hot Functional Testing 92702 Closed
4 PLANT STATUS At the start of this inspection period, Unit 3 was in Mode 4 (Safe Shutdown) and the licensee was performing a maintenance outage prior to resumption of plant startup testing activities. On July 5, Unit 3 entered Mode 3 (Hot Standby), the licensee completed its final maintenance outage activities and made preparations for plant startup.
On July 6, Unit 3 entered Mode 2 (Startup) and the licensee performed a reactor startup. The main generator was synchronized to the electrical grid on July 8. The unit entered island mode (i.e., with the main turbine disconnected from the switchyard and supplying house loads through the unit auxiliary transformers) from about 18% power for system tuning by opening switchyard breakers 161750 and 161850. Upon successful completion of island mode tuning, the main generator was once again synchronized to the electrical grid and the licensee continued power ascension. On July 9, the unit reached 100% power.
On July 9, during performance of the load rejection startup test from 100% power, the Unit 3 reactor automatically tripped from about 45% power due to low reactor coolant flow due to loss of power to the reactor coolant pumps. The trip was not complex, and all safety related systems responded normally post-trip. Plant operators stabilized the unit in Mode 3 on natural circulation flow. Unit 3 remained in Mode 3 while the licensee performed corrective maintenance activities and restored plant systems to operation.
On July 14, Unit 3 entered Mode 2 and the licensee performed a reactor startup. The main generator was synchronized to the electrical grid on July 15, and the licensee continued with plant startup testing activities.
On July 15, the licensee completed the loss of offsite power startup test procedure to demonstrate the plant response following a plant trip with no offsite power available. Operators manually tripped the main turbine (per the procedure) and the reactor automatically tripped as expected due to low reactor coolant flow due to loss of power to the reactor coolant pumps. The trip was not complex, and all safety related systems responded normally post-trip. Plant operators stabilized the unit in Mode 3 on natural circulation flow. Unit 3 remained in Mode 3 while the licensee performed corrective maintenance activities and restored plant systems to operation.
On July 18, Unit 3 entered Mode 2 and the licensee performed a reactor startup. The main generator was synchronized to the electrical grid on July 20, and the licensee continued with plant startup testing activities.
On July 21, during reperformance of the load rejection startup test from 100% power, the Unit 3 reactor automatically tripped from about 32% power due to low reactor coolant pump speed due to loss of power to the reactor coolant pumps. The trip was not complex, and all safety related systems responded normally post-trip. Plant operators stabilized the unit in Mode 3 on natural circulation flow. Unit 3 remained in Mode 3 while the licensee performed corrective maintenance activities and restored plant systems to operation.
On July 25, Unit 3 entered Mode 2 and the licensee performed a reactor startup. The main generator was synchronized to the electrical grid on July 26, and the licensee continued with plant startup testing activities.
On July 26, the licensee completed the load rejection startup test from 100% power to
5 demonstrate the capability of the plant to sustain a full load rejection. Upon successful completion of the test, the main generator was once again synchronized to the electrical grid and the licensee continued power ascension. On July 28, the unit reached 100% power.
On July 28, the licensee notified the NRC of the successful completion of Unit 3 power ascension tests as required by Condition 2.D.(5)(b) of the Vogtle Unit 3 Combined License (ML23209A830). Upon this notification, Vogtle Unit 3 is authorized to operate at steady state power levels up to 100% thermal power (3400 megawatts thermal).
At the end of this inspection period, the unit was operating at 100% power.
INSPECTION SCOPES Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY 71111.01 - Adverse Weather Protection Impending Severe Weather Sample (IP Section 03.02) (2 Samples)
(1)
The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending high winds and heavy rainfall due to hurricane Idalia on August 30.
(2)
The inspectors evaluated the adequacy of the overall preparations to protect risk significant systems from impending severe (hot) weather during the week of July 30.
71111.04 - Equipment Alignment Partial Walkdown Sample [AP1000] (IP Section 03.01) (1 Sample)
The inspectors evaluated system configurations during a partial walkdown of the following system:
(1)
Startup feedwater system train A on July 12.
6 71111.05 - Fire Protection Fire Area Walkdown and Inspection Sample [AP1000] (IP Section 03.01) (1 Sample)
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)
Spent fuel pool cooling pump and heat exchanger rooms on July 11.
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 performance of:
3-GEN-ITPS-633, "100% Load Rejection Startup Test Procedure," on July 9 and July 21; and 3-GEN-ITPS-638, "Loss of Offsite Power Startup Test Procedure," on July 15.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)
(1)
The inspectors observed and evaluated licensed operator requalification training in the plant simulator on July 17.
(2)
The inspectors observed and evaluated licensed operator requalification training in the plant simulator on July 31.
71111.12 - Maintenance Effectiveness Maintenance Effectiveness [AP1000] (IP Section 03.01) (1 Sample)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
(1)
Standby diesel generators during the weeks of August 27, September 3, and October 1.
71111.13 - Maintenance Risk Assessments and Emergent Work Control Risk Assessment and Management Sample [AP1000] (IP Section 03.01) (1 Sample)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned work activity to ensure configuration changes and appropriate work controls were addressed:
(1)
Reactor coolant system (RCS) drain to reduced inventory to complete reactor assembly and RCS fill/vent following initial fuel load during the week of August 20.
7 71111.24 - Testing and Maintenance of Equipment Important to Risk The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:
Reactor Coolant System Leakage Detection Testing [AP1000] (IP Section 03.01) (1 Sample)
(1)
NMP-02-009, RCS Unidentified Leakage Monitoring Program, and 3-RCS-OTS 001, Reactor Coolant System and Main Steam Line Leak Determination RADIATION SAFETY 71124.01 - Radiological Hazard Assessment and Exposure Controls Radiological Hazard Assessment (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated how the licensee identifies the magnitude and extent of radiation levels and the concentrations and quantities of radioactive materials and how the licensee assesses radiological hazards.
Instructions to Workers (IP Section 03.02) (1 Sample)
(1)
The inspectors evaluated how the licensee instructs workers on plant-related radiological hazards and the radiation protection requirements intended to protect workers from those hazards.
Contamination and Radioactive Material Control (IP Section 03.03) (2 Samples)
The inspectors observed/evaluated the following licensee processes for monitoring and controlling contamination and radioactive material:
(1)
Contamination surveys on tools and equipment associated with work on Spent Fuel System.
(2)
Personnel exiting the Unit 3 Radiological Controlled Area (RCA)
Radiological Hazards Control and Work Coverage (IP Section 03.04) (2 Samples)
The inspectors evaluated the licensee's control of radiological hazards for the following radiological work:
(1)
Multiple Locked High Radiation Area (LHRA) entries by operations and RP in support of tagout for Spent Fuel System (SFS) maintenance.
(2)
Entry into WLS demineralizer vault Locked High Radiation Area (LHRA) by mechanical maintenance personnel.
8 High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (4 Samples)
The inspectors evaluated licensee controls of the following high radiation areas (HRAs) and very high radiation areas (VHRAs):
(1)
Unit 3 upper and lower containment airlock Locked High Radiation Area (LHRA) controls (2)
Unit 3 Effluent Holdup Tank (EHT) Locked High Radiation Area (LHRA)
(3) 66' elevation demineralizer vault Locked High Radiation Area (LHRA)
(4)
Spent Fuel System (SFS) mechanical penetration room Locked High Radiation Area (LHRA)
Radiation Worker Performance and Radiation Protection Technician Proficiency (IP Section 03.06) (1 Sample)
(1)
The inspectors evaluated radiation worker and radiation protection technician performance as it pertains to radiation protection requirements.
71124.05 - Radiation Monitoring Instrumentation Walkdowns and Observations (IP Section 03.01) (5 Samples)
The inspectors evaluated the following radiation detection instrumentation during plant walkdowns:
(1)
Area radiation monitors in the auxiliary and annex buildings (2)
Portable ion chamber survey instruments stored ready for use (3)
Portable telescoping survey instruments ready for use (4)
Portable friskers in the auxiliary building (5)
Continuous air monitors in the auxiliary building Calibration and Testing Program (IP Section 03.02) (11 Samples)
The inspectors evaluated the calibration and testing of the following radiation detection instruments:
(1) 3-PXS-RE160, Containment High Range Area Monitor, 11/23/22 (2) 3-PXS-RE161, Containment High Range Area Monitor, 11/23/22 (3) 3-VBS-RE002A, Main Control Room Air Intake, Iodine Channel, 11/14/22 (4)
VEGP-HP-1925, ARGOS, 10/12/22 (5)
VEGP-HP-3060, ARGOS, 12/13/22 (6)
VEGP-HP-3082, Tele-STTC, 7/18/23 (7)
VEGP-HP-3045, Ludlum 9-3, 10/14/22 (8)
VEGP-HP-1850, Neutron ball, 6/6/23 (9)
VEGP-RP-1895, Ludlum 177, 4/30/23 (10)
VEGP-HP-1927, GEM-5, 10/12/22 (11)
VNP-WBC2, Fastscan Whole Body Counter, 4/29/23
9 Effluent Monitoring Calibration and Testing Program Sample (IP Section 03.03) (3 Samples)
The inspectors evaluated the calibration and maintenance of the following radioactive effluent monitoring and measurement instrumentation:
(1) 3-VFS-RE101, 102, 103, 104A, 104B, Plant Vent Effluent Monitor, 2/21/23 (2) 3-WLS-RE229, Liquid Waste Discharge Monitor, 2/22/23 (3)
VFS-FT105, Plant Vent Flowmeter Functional Check, 8/3/23 OTHER ACTIVITIES - BASELINE 71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
OR01: Occupational Exposure Control Effectiveness Sample [AP1000] (IP Section 02.15) (1 Sample)
(1)
January 1, 2023, through August 24, 2023 PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences (RETS/ODCM) Radiological Effluent Occurrences Sample
[AP1000] (IP Section 02.16) (1 Sample)
(1)
October 14, 2022, through July 14, 2023 71153 - Follow Up of Events and Notices of Enforcement Discretion Event Follow up [AP1000] (IP Section 03.01) (2 Samples)
(1)
Reactor Trip Response On July 9, with Unit 3 in Mode 1 at approximately 45% power, the reactor automatically tripped due to low reactor coolant flow due to loss of power to the reactor coolant pumps (RCPs) during plant startup testing. The trip was not complex, and all safety related systems responded normally post-trip. Plant operators stabilized the plant on natural circulation flow with decay heat being removed by discharging steam via steam generator power operated relief valves to atmosphere.
At the time of the trip, the licensee was performing the load rejection startup test from 100% power. The expected plant response when opening breakers between the main turbine generator and the switchyard was a turbine generator runback with the plants electrical distribution system on island mode (i.e., with the generator disconnected from the switchyard and supplying house loads through the unit auxiliary transformers). After opening switchyard breakers 161750 and 161850, the rapid power reduction system brought reactor power down as expected; however, a turbine trip unexpectedly occurred due to a High-2 moisture separator shell level within approximately one minute of initiating the load rejection. Additionally, moisture separator reheater drain pump B tripped on Low-2 level in the drain tank. The generator tripped due to the turbine trip and power was lost to the unit auxiliary transformers. A residual transfer of electrical power to the reserve auxiliary
10 transformers resulted in a momentary loss of off-site power, which led to the loss of the RCPs and all secondary systems large pumps.
The inspectors observed operator actions post-trip, interviewed plant personnel, performed plant tours, and reviewed operator logs to evaluate operator actions during the event.
(2)
Reactor Trip Response On July 21, with Unit 3 at approximately 30% power, the reactor automatically tripped due to low RCP speed due to loss of power to the RCPs during plant startup testing.
The trip was not complex, and all safety related systems responded normally post-trip. Plant operators stabilized the plant on natural circulation flow with decay heat being removed by startup feedwater flow and steam generator power operated relief valves discharging to atmosphere.
At the time of the trip, the licensee was reperforming the load rejection startup test from 100% power. The expected plant response when opening breakers between the main turbine generator and the switchyard was a turbine generator runback with the plants electrical distribution system on island mode. After opening switchyard breakers 161750 and 161850, the rapid power reduction system brought reactor power down as expected; however, the generator tripped unexpectedly due to actuation of the MSU-A 86 lockout relay due to overcurrent (overexcitation) on the voltage regulator and power was lost to the unit auxiliary transformers. A residual transfer of electrical power to the reserve auxiliary transformers resulted in a momentary loss of off-site power, which led to the loss of the RCPs and all secondary systems large pumps.
The inspectors observed operator actions post-trip, interviewed plant personnel, performed plant tours, and reviewed operator logs to evaluate operator actions during the event.
Event Report [AP1000] (IP Section 03.02) (2 Samples)
The inspectors evaluated the following licensee event reports (LERs):
(1)
LER 05200025/2023-004-00, "Manual Reactor Protection System Actuation due to Condenser Flanges Not Removed during Construction." (ADAMS Accession No. ML23181A173)
(2)
LER 05200025/2023-005-00, "Automatic Reactor Protection System Actuation During Startup Testing Due to Inadequate Turbine Trip Logic." (ADAMS Accession No. ML23249A166)
OTHER ACTIVITIES - TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 92702 - Follow-Up on Traditional Enforcement Actions Including Violations, Deviations, Confirmatory Action Letters, and Orders (1)
The inspectors reviewed NOV 05200025/2022011-01 and NOV 0520002022011-02 and determined: (1) the reason for the violations; (2) the corrective actions that have been taken and the results achieved; and (3) the date when full compliance was
11 achieved is already adequately addressed on the docket in the licensee's written response letter dated April 26, 2023 (ADAMS Accession No. ML23116A248). These violations are closed.
INSPECTION RESULTS Failure to Adequately Implement Severe Weather Procedure NMP-OS-017 Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05200025/2023003-01 Open/Closed
[H.4] -
Teamwork 71111.01 The inspectors identified a Green finding of very low safety significance for the licensees failure to implement procedure NMP-OS-017, Severe Weather, Version 3.1, by failing to remove or secure equipment that could become a missile due to severe weather affecting the plant site.
==
Description:==
On August 30, 2023, a tropical storm with predicted high winds was forecasted onsite. The licensee entered procedure 3-AOP-901, Acts of Nature, Version 1.0, and procedure 4-AOP-901, Acts of Nature, Version 1.0, which provided instructions to respond to a threat of plant damage or actual plant damage due to an act of nature such as severe weather (hurricane, high winds, winter storm, etc.). The procedures directed the licensee to walk down the site and remove or secure equipment that could become a missile or cause significant blockage of critical intake screens (air/water) in accordance with procedure NMP-OS-017, Sever Weather, Version 3.1.
The Severe Weather Preparation Checklists contained in the attachments of procedure NMP-OS-017 directed the licensee, in part, "to perform walkdowns of outside areas...and secure equipment that may damage other equipment if blown." After verifying the licensee completed its walkdowns to validate all equipment was secure that could be blown, the inspectors performed a walkdown of the site and identified items were left unsecured around the site that could be blown and damage other equipment. These unsecured items included sheets of plywood, dimensional lumber, trash cans, ladders, folding tables, chairs, tarps, scaffolding, picnic tables, and miscellaneous debris.
Corrective Actions: The licensee entered this finding into its corrective action program as condition report (CR) 11002200 and CR 11006034 and initiated actions to update the procedural guidance to clarify expectations and increase communications to improve future implementation of the severe weather procedures. Additionally, the licensee issued a crew learning memo to clearly document future expectations regarding severe weather preparations.
Corrective Action
References:
CR 11002200 and CR 11006034.
Performance Assessment:
Performance Deficiency: The inspectors determined the licensees failure to adequately implement procedure NMP-OS-017, Severe Weather, Version 3.1, to prepare for the effects of severe weather was a performance deficiency warranting a significance evaluation.
Screening: Consistent with the guidance in IMC 0612, Issue Screening, Appendix B, Issue Screening Directions, dated August 8, 2022, the inspectors determined the performance
12 deficiency was a finding of more than minor significance because it was associated with the protection against external factors attribute of the initiating events cornerstone and adversely affected the cornerstone objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. The failure to remove or secure items in accordance with severe weather procedures had the potential to result in the licensee damaging or losing the ability to utilize the preferred offsite power source via the switchyard as well as the standby diesel generators, which are a backup power source. The inspectors also reviewed the examples of minor issues in IMC 0612, Appendix E, "Examples of Minor Issues," dated January 1, 2021, and found no examples related to this issue.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. In accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, "Initial Characterization of Findings," dated December 20, 2019, Table 3, "SDP [Significance Determination Process] Appendix Router," the inspectors determined this finding would require review using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, dated January 1, 2021, since the reactor was at 100% power. The inspectors performed a Phase 1 SDP review of this finding using the guidance provided in IMC 0609, Appendix A, and determined this finding was of very low safety significance (Green) based on No answers to all of the Exhibit 2 - Mitigating Systems Screening Questions.
Cross-Cutting Aspect: H.4 - Teamwork: Individuals and work groups communicate and coordinate their activities within and across organizational boundaries to ensure nuclear safety is maintained. The licensee failed to establish clear communications between Unit 3 and Unit 4 shift personnel on roles and responsibilities during severe weather events. This led to numerous examples of equipment not being secured that were required to be.
Enforcement: Inspectors did not identify a violation of regulatory requirements associated with this finding.
Unresolved Item (Closed)
Maintenance Rule Evaluations for Plant Level Events URI 05200025/2023002-01 71111.12
==
Description:==
In the second quarter of 2023, the inspectors reviewed CAR 411146, Unit 3 Reactor and Turbine Tripped Multiple Times Resulting in Challenges to Startup, which collectively evaluated multiple main turbine and reactor trips during startup testing in March and April 2023. Four main turbine trips and one reactor trip occurred during plant startup testing in March 2023. A fifth main turbine trip and a second reactor trip occurred in April 2023. During the inspection, the inspectors requested to review the licensees maintenance rule evaluations associated with the above turbine and reactor trips. In response to the inspectors questions, the licensee found that only one of reactor trips and one of the turbine trips had been evaluated. No evaluations had been performed for system or component failures associated with any of the other four turbine trips or for the second reactor trip. This was contrary to the licensees procedure standard (NMP-ES-027, Maintenance Rule Program) for implementing its maintenance rule program, which required maintenance rule evaluations be performed within 30 days from the event date without an approved extension.
The inspectors opened this unresolved item pending review of the licensee's completed maintenance rule evaluations and condition report evaluations to determine whether a performance deficiency or violation of regulatory requirements existed.
13 During this quarter, the inspectors reviewed the completed maintenance rule evaluations and condition report evaluations and determined the licensees failure to complete maintenance rule evaluations in accordance with NMP-ES-027 for system or component failures associated with the four turbine trips and one reactor trip was a performance deficiency of minor safety significance. The mitigating systems cornerstone objectives were not adversely affected because, when the maintenance rule evaluations were subsequently performed, it was still demonstrated that performance of the affected systems or components were being effectively controlled through appropriate preventive maintenance such that the systems or components remained capable of performing their intended functions (i.e., the requirements of 10 CFR 50.65(a)(1)/(a)(2) were always met). Additionally, because the requirements of 10 CFR 50.65(a)(1)/(a)(2) were always met, no violation of regulatory requirements was identified.
Corrective Action Reference(s): CRs 10975594, 10978631 and 10978278 Licensee-Identified Non-Cited Violation 71124.05 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: Licensee Technical Specification (TS) 5.4.1 requires that procedures be established for all programs listed in TS 5.5, which includes procedures for surveillance tests on liquid and gaseous effluent monitoring instrumentation, as specified in the Offsite Dose Calculation Manual (ODCM). Contrary to this, on October 14, 2022, when the ODCM became effective during initial fuel load, the procedures required to perform quarterly functional testing on liquid and gaseous effluent monitors had not yet been created. As a result, the initial surveillances required by ODCM Attachments 2 and 7 were not performed within 90 days plus grace period, which lead to multiple effluent monitoring instruments being declared out-of-service and required the implementation of compensatory sampling. The failure to establish procedures for effluent monitoring instrument testing was identified by licensee staff prior to exceeding the grace period and was documented in multiple CRs. All instruments have since been returned to service.
Significance/Severity: Green. Using Inspection Manual Chapter 0609, Appendix D, "Public Radiation Safety Significance Determination Process", inspectors determined the Finding was of very low safety significance. Specifically, the issue was a Finding in the effluent release program but did not represent a substantial failure to implement the effluent program and there were no releases from the site that exceeded the public dose limits of 10 CFR 50, Appendix I, or 10 CFR 20.1301(e).
Corrective Action
References:
CRs 10941821, 10936848, 10936851, 10936963, 10936969, 10936972, 10936977, 10936979.
Failure to Remove Manufacturer Shipping Flanges from the Main Condenser A and C Flashbox Nozzles Results in Turbine/Reactor Trips Cornerstone Significance Cross-Cutting Aspect Report Section
14 Initiating Events Green FIN 05200025/2023003-02 Open/Closed
[H.1] -
Resources 71153 A Green finding of very low safety significance was self-revealed from a manual turbine trip and manual reactor trip during plant startup testing. The licensee failed to remove manufacturer shipping flanges from the main condenser A and C flashbox nozzles, as specified on the installation drawing, which led to the event.
==
Description:==
On May 2, with Unit 3 in Mode 1 at approximately 77% reactor power, three feedwater heater strings sequentially isolated requiring a manual turbine trip. Operators manually tripped the turbine as directed by procedure based on the loss of two or more feedwater heater strings.
The rapid power reduction system actuated as designed to lower reactor power. The turbine trip caused a sudden change in steam flow to the main condenser and feedwater heaters (i.e., extraction steam). This caused corrosion products to become displaced, resulting in the clogging of all three main feedwater/booster pumps suction screens. With high differential pressures across the suction screens, operators had to trip the reactor as directed by procedure and secured the main feedwater/booster pumps.
Operators manually tripped the reactor from 14% power prior to an automatic reactor trip on low steam generator levels. All safety related systems responded normally post trip.
Operators stabilized the plant with decay heat being removed by discharging steam via the turbine bypass valves to the main condenser.
The licensees cause evaluation attributed the direct cause of the event to be inadequate work instructions and work practices during construction. In late 2013, the main condenser A and C flashboxes were installed with manufacturer shipping flanges in place that rendered ineffective the normal drain paths from the low pressure drain tanks to the main condenser.
This, in turn, resulted in overuse and excessive cycling of the feedwater heater drain cooler bypass air-operated valves (3-HDS-V021A/B/C). A failure of 3-HDS-V021B due to excessive cycling initiated the feedwater heater string isolations, which then led to the manual turbine and manual reactor trips. Excessive cycling of the valves was not adequately questioned, evaluated, and addressed prior to the valve's failure. The licensees review of legacy construction events and work packages identified the work orders that installed the flashboxes on main condensers A and C did not contain instructions to remove the shipping flanges (part FB-119) from flashbox nozzles S-47, S-48, and S-49, as directed by the construction drawing (SV3-ME01-V2-005).
The licensee completed a 4-hour notification call (Event Notification 56497) on May 2 to report the reactor protection system (RPS) actuation while critical as required by 10 CFR 50.72(b)(2)(iv)(B). The licensee submitted LER 05200025/2023-004-00 to report this event in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event or condition that resulted in manual actuation of the RPS.
Corrective Actions: The licensee entered this issue into its corrective action program as CR 10968544 to evaluate the causes and to identify appropriate corrective actions. The licensee removed the flanges from the drain lines to restore the normal heater drains flow path to the main condenser, repaired the feedwater heater drain cooler bypass valves, and cleaned/inspected the main feedwater pump suction strainers to restore feedwater flow to the steam generators.
15 Corrective Action
References:
CR 10968544
16 Performance Assessment:
Performance Deficiency: The inspectors determined the licensees failure to remove manufacturer shipping flanges from the main condenser A and C flashbox nozzles, as specified on the installation drawing, was a licensee performance deficiency warranting a significance evaluation.
Screening: Consistent with the guidance in IMC 0612, Issue Screening, Appendix B, Issue Screening Directions, dated August 8, 2022, the inspectors determined the performance deficiency was a finding of more than minor significance because it was associated with the Procedure Quality attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the failure to remove manufacturer shipping flanges from the main condenser A and C flashbox nozzles, as specified on the installation drawing, resulted in blockage of the normal heater drains flow path through the feedwater heater coolers and excessive cycling of the drain cooler bypass valves, which led to premature failure of the valve stem for 3-HDS-V021B, sequential isolation of feedwater heater strings, and a manual turbine trip. The inspectors also reviewed the examples of minor issues in IMC 0612, Appendix E, Examples of Minor Issues, dated January 1, 2021, and found no similar examples.
Significance: The inspectors assessed the significance of the finding using Detailed Risk Evaluation (blank significance section) In accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, "Initial Characterization of Findings," dated December 20, 2019, Table 3, "SDP [Significance Determination Process] Appendix Router,"
the inspectors determined this finding would require review using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, dated November 30, 2020, since it involved a transient initiator with the unit operating at power. The inspectors performed a Phase 1 SDP review of this finding using the guidance provided in IMC 0609, Appendix A, Exhibit 1, Initiating Events Screening Questions, and determined this finding would require a detailed risk evaluation because the finding caused 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 (e.g., loss of condenser, loss of feedwater).
The Region II Senior Risk Analyst (SRA) conducted an assessment of the risk significance of the finding using SAPHIRE 8, Version 8.2.6 and the Vogtle 3&4 SPAR Model, Version 8.81, dated August 14, 2022. The SRA set the exposure time to 57 days (from the date of initial criticality (March 6) until the event on May 2). The RPS actuation was valid since the plant response produce directs operators to manually trip the reactor due to a loss of main feedwater. The SRA modelled the condition as a plant transient with a loss of all main feedwater pumps. The dominant accident sequence was a Loss of Main Feedwater Initiator, with a failure the RPS to trip the reactor, and a failure of secondary relief valves to lift or to reseat. The change in core damage frequency was less than 1E-6.
Based on the results of the detailed risk evaluation, the inspectors determined the finding was of very low safety significance.
Cross-Cutting Aspect: H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety. The inspectors determined the finding had a cross-cutting aspect of Resources in the Human
17 Performance area because the proximate cause was attributed to be inadequate work instructions and work practices for installation of the flashboxes on the main condenser.
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 October 24, 2023, the inspectors presented the integrated inspection results to Mr. Glen Chick, VEGP Units 3 & 4 Executive Vice President and other members of the licensee staff.
On August 25, 2023, the inspectors presented the Radiation Protection Inspection Exit Meeting inspection results to P. Martino, Vogtle Unit 3 Site Vice President, and other members of the licensee staff.
18 DOCUMENTS REVIEWED Inspection Procedure Type Designation Description or Title Revision or Date CR 11002200 NRC Identified Gap Implementing NMP-OS-017 08/30/2023 Corrective Action Documents Resulting from Inspection CR 11006034 Procedure enhancements from storm prep lessons learned 09/12/2023 3-AOP-901 Acts of Nature Version 1 NMP-OS-017 Severe Weather Version 3.1 71111.01 Procedures NMP-OS-020 Station Response to Southern Company System Alert Conditions Version 2 CR 10987144 3-FWS-V015B missing stem protector Corrective Action Documents Resulting from Inspection CR 10987145 3-FWS-V112A Gag Device Drawings APP-FWS-M6-002 Piping and Instrumentation Diagram Main and Startup Feedwater System Revision 18 71111.04 Procedures 3-FWS-SOP-002 Startup Feedwater System Revision 4 Engineering Evaluations TE 45001409 As Built Pre-fire Plans based on Walkdowns 9/2/2022 71111.05 Fire Plans B-PFP-ENG-001-F3121 Pre-Fire Plan - Auxiliary Building RCA El 82'6" Revision 2 Engineering Evaluations SVP-SV0-230225 Westinghouse Letter
Subject:
Evaluation of Retest Reqirements for 3-GEN-ITPS-633 (TE 1132118) 08/25/2023 Miscellaneous APP-GW-T1-696 AP1000 Startup Test Specification, Section 2.9, GEN-633A, 100 Percent Load Rejection Startup Test Specification Revision 2 3-GEN-ITPS-633 100% Load Rejection Startup Test Procedure Version 4.0 71111.11Q Procedures 3-GEN-ITPS-638 Loss of Offiste Power Startup Test Procedure Version 3.0 CAR 411146 Unit 3 Reactor and Turbine Tripped Multiple Times Resulting in Challenges to Startup CR 10960257 Main Turbine Trip on GCB [Generator Circuit Breaker] BU 86 Lockout CR 10961184 Main Turbine Trip on a GCB BU 86 Lockout Corrective Action Documents CR 10961224 Turbine Reference Load Anomalies During Turbine Trip 71111.12 Corrective Action CR 10975446 MRule (a)(1) Evaluation Required for PLE [Plant Level
19 Inspection Procedure Type Designation Description or Title Revision or Date Event] on 05/02/2023 CR 10975524 MRule (a)(1) for PLE on 05/02/2023 CR 10975594 NMP-ES-027 SV34 Procedural Violation Due to Lack of Location Codes CR 10978278 Need Additional Maintenance Rule Evaluation for Event Documented in CR 10956663 CR 10978631 Request for MREVAL for 04/10/2023 Turbine and Reactor Trip Events Documents Resulting from Inspection CR 10985562 Perform (a)(1) MRule Assessment of TOS EVAL-VEGP34-ECS-05850 (a)(1) Review for Unit 3 Reactor Trip on March 15, 2023 05/25/2023 EVAL-VEGP34-TOS-06070 Main Turbine Control and Diagnostics System Plant Level PC Exceedance 08/07/2023 TE 1125486 Perform Maintenance Rule Evaluation for CR 10956663 for Unit 3 Reactor Trip TE 1125964 Perform Maintenance Rule Evaluation for CR 10958946 -
ZAS TE 1130230 Perform (a)(1) Eval Against FWS for the Reactor Trip of CR 10975446 TE 1130272 Perform MREVAL for CR 10978278 (Rx Trip event documented in condition report 10956663 dated 3/16/2023)
TE 1130292 Perform MREVAL for CR 10978631 - the turbine trip TE 1130294 Perform MREVAL for CR 10978631 - the Reactor Trip Engineering Evaluations TE 1131983 Perform (a)(1) Assessment of 04/10/2023 Rx Trip Maintenance Rule Implementation Guidance for 103(g) 02/14/2022 NUMARC 93-01 Nuclear Energy Institute Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants Revision 4F Miscellaneous Regulatory Guide 1.160 Monitoring the Effectiveness of Maintenance at Nuclear Power Plants Revision 4 Procedures NMP-ES-027 Maintenance Rule Program Version 10.4 71111.13 Procedures NMP-OS-020 Station Response to Southern Company System Alert Conditions Revision 2 Miscellaneous NMP-02-009 RCS Unidentified Leakage Monitoring Program Version 5 71111.24 Procedures 3-RCS-OTS Reactor Coolants System and Main Steam Line Leak Version 1
20 Inspection Procedure Type Designation Description or Title Revision or Date 001 Determination Corrective Action Documents Resulting from Inspection 11000087 RCA scaffolds missing required labeling 08/24//2023 3-RMS-ITPS-601 Biological Shield Survey Startup Test Procedure Version 2.0 Procedures NMP-HP-300 Radiation and Contamination Surveys Version 5.8 Survey #4784 Unit 3 117' Power Ascension 05/01/2023 71124.01 Radiation Surveys Survey #5413 Unit 3 117' Power Ascension 05/27/2023 71124.05 Procedures NMP-HP-79 Operation and Calibration of the Mirion RDS-31iTx/RDS-32iTx Version 7 CAR 437717 Feedwater String Isolations Result in Manual Turbine Trip and Manual Reactor Trip Revision 0 CAR 474655 Turbine Trip and Reactor Trip during Performance of Load Reject Test 3-GEN-ITPS-633 Revision 0 CR 10968544 U3 Reactor Trip CR 10969579 Blind Flanges Installed on LP Drain Tank Inlets to Condenser CR 10989831 Electrical Maintenance to gather relay data.
07/21/2023 Corrective Action Documents TE 1133334 Submit Unit 3 LER 2023-006-00 07/26/2023 EN 56497 Manual Reactor Trip 05/02/2023 EN 56614 Automatic Reactor Trip 07/09/2023 LER 05200025/2023-004-00 Manual Reactor Protection System Actuation due to Condenser Flanges Not Removed during Construction 06/30/2023 LER 05200025/2023-005-00 Automatic Reactor Protection System Actuation During Startup Testing Due to Inadequate Turbine Trip Logic 09/06/2023 71153 Miscellaneous Reactor Trip Report No. 3 003 Reactor Trip Report 05/03/2023