IR 05000269/2025003
| ML25352A078 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/30/2025 |
| From: | Robert Williams NRC/RGN-II/DORS/PB1 |
| To: | Snider S Duke Energy Carolinas |
| References | |
| IR 2025003 | |
| Download: ML25352A078 (0) | |
Text
SUBJECT:
OCONEE NUCLEAR STATION - INTEGRATED INSPECTION REPORT 05000269/2025003 AND 05000270/2025003 AND 05000287/2025003
Dear Steven Snider:
On September 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Oconee Nuclear Station. On December 8, 2025, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
Due to the temporary cessation of government operations, which commenced on October 1, 2025, the NRC began operating under its Office of Management and Budget-approved plan for operations during a lapse in appropriations. Consistent with that plan, the NRC operated at reduced staffing levels throughout the duration of the shutdown. However, the NRC continued to perform critical health and safety functions and make progress on other high-priority activities associated with the ADVANCE Act and Executive Order 14300. On November 13, 2025, following the passage of a continuing resolution, the NRC resumed normal operations. However, due to the 43-day lapse in normal operations, the Office of Nuclear Reactor Regulation granted the Regional Offices an extension on the issuance of the calendar year 2025 inspection reports that should have been issued by November 13, 2025, to December 31, 2025. The NRC resumed the routine cycle of issuing inspection reports on November 13, 2025.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
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 violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional December 30, 2025 Administrator, Region II; the Director, Office of Enforcement; and the NRC Resident Inspector at Oconee Nuclear Station.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC Resident Inspector at Oconee Nuclear Station.
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Robert E. Williams, Jr., Chief Projects Branch 1 Division of Operating Reactor Safety Docket Nos. 05000269 and 05000270 and 05000287 License Nos. DPR-38 and DPR-47 and DPR-55
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000269, 05000270 and 05000287
License Numbers:
Report Numbers:
05000269/2025003, 05000270/2025003 and 05000287/2025003
Enterprise Identifier:
I-2025-003-0024
Licensee:
Duke Energy Carolinas, LLC
Facility:
Oconee Nuclear Station
Location:
Seneca, South Carolina
Inspection Dates:
July 1, 2025, to September 30, 2025
Inspectors:
N. Smalley, Senior Resident Inspector
D. Dang, Resident Inspector
E. Robinson, Resident Inspector
A. Craig, Project Engineer
Approved By:
Robert E. Williams, Jr., Chief
Projects Branch 1
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Oconee Nuclear Station, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. A licensee-identified non-cited violation is documented in report section: 71152
List of Findings and Violations
Improper Implementation of Letdown Filter Maintenance Resulting in Excessive RCS Leakage and a Notice of Unusual Event Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000269/2025003-01 Open/Closed
[H.12] - Avoid Complacency 71111.12 A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a, was identified for the licensees failure to implement the established procedure for replacement of the Unit 1 B train letdown filter, in accordance with Regulatory Guide 1.33,
Revision 2, Appendix A, February 1978. Specifically, the licensee failed to perform maintenance on the intended component and instead altered the in-service Unit 1 A train letdown filter, resulting in a leak of approximately 26 gallons per minute (gpm) and a corresponding declaration of a Notice of an Unusual Event (NOUE).
Additional Tracking Items
None.
PLANT STATUS
Unit 1 operated at or near 100 percent rated thermal power (RTP) for the entire inspection period.
Unit 2 operated at or near 100 percent RTP for the entire inspection period.
Unit 3 operated at or near 100 percent RTP at the beginning of the inspection period. On July 21, 2025, power was reduced to 51 percent to recover and relatch a dropped control rod.
Unit 3 returned to 100 percent RTP on July 22, 2025. Unit 3 operated at or near 100 percent RTP for the remainder of the inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (2 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
(1)2B motor-driven emergency feedwater train restoration following intrusive maintenance in motor cooling equipment on August 6, 2025
- (2) Keowee Hydro Unit (KHU) #1 and underground emergency power path with the 230kV yellow bus out of service on September 8, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
- (1) Fire zone 106: Unit 1 cable room on July 18, 2025
- (2) Fire zone 15: Unit 2 main feedpump area on July 21, 2025
- (3) Fire zone 29: Unit 3 4160V switchgear on July 23, 2025
- (4) Fire zone 17: Unit 2 turbine building basement and hotwork controls on August 4, 2025
- (5) Fire zone 110: Unit 1/2 control room on August 19, 2025
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) Unit 2 reactor building cooling units
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 Unit 3 runback due to dropped control rod on July 21, 2025.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated a simulator operator training exam in accordance with ASE-35 on July 29, 2025.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (2 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
- (1) NCR 2538150, Unit 1/2 A low pressure service water (LPSW) pump bearing failure
- (2) NCR 2567951, review of Unit 1 B letdown filter replacement and corresponding issues
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (2 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 3 green risk due to 3C low pressure injection pump and valve maintenance, on July 10, 2025
- (2) Unit 2 green risk due to 2B motor-driven emergency feedwater pump train maintenance and hotwork on low pressure service water piping, on August 4, 2025
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (7 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) NCRs 2563528 and 2563889, Keowee Hydro Unit 2 speed sensor and wicket gate position indication problems on governor control subsystem A
- (2) NCR 2562749, standby shutdown facility (SSF) auxiliary service water flow gauge indication
- (3) NCR 2558007, SSF diesel fuel oil tank level increase
- (4) NCR 2563525, pumps not running on alternate chilled water system chiller 2
- (5) NCRs 2463396 and 2566197, restoration of the Unit 1 anticipated transient without scram mitigation circuitry system (AMSAC) following spurious channel actuation and alarm
- (6) NCR 2546416, protected service water high pressure injection transfer switch environmental qualification
- (7) NCR 2567168, condenser circulating water valve CCW-487 seat leakage
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) Engineering change (EC) 420621, SSF emergency diesel generator automatic voltage regulator (AVR) replacement
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:
Post-Maintenance Testing (PMT) (IP Section 03.01) (5 Samples)
- (1) Low pressure service water valve, 2LPSW-252, diagnostic testing and stroke time test following disassembly, on August 4, 2025
- (2) PT/0/A/0620/009, Keowee Hydro Unit 2 operation, following governor control speed switch string check, semi-annual surveillance, and relay testing, on August 5, 2025
- (3) PT/0/A/0620/009, "Keowee Hydro Operation," following air circuit breaker ACB-4 maintenance, on August 21, 2025
- (4) PT/2/A/0203/006A, "Unit 2 A LPI Pump Test," following maintenance on low pressure injection (LPI) pump 2LP-11, on August 21, 2025
- (5) PT/3/A/0203/006A, "Unit 3B LPI Pump Test," following maintenance on LPI pump 3LP-33, on September 25, 2025
Surveillance Testing (IP Section 03.01) (3 Samples)
- (1) IP/3/A/0315/014 A, "TXS (Teleperm XS software) reactor protection system (RPS)
Interposing Relay Test and Control Rod Drive Breaker Trip Timing Test," on July 21 and 23, 2025
- (2) PT/0/A/0610/002, "External Grid Trouble Protective System Logic and Switchyard Isolation Logic Test," on September 5, 2025
- (3) PT/0/A/0500/020, "Protected Service Water (PSW) Power Path Test," on September 19, 2025
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
- (1) Training drill 2025-03 on August 20, 2025, which included operations shift B and emergency response organization team
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS06: Emergency AC Power Systems (IP Section 02.05)===
- (1) Unit 1 (July 1, 2024, through June 30, 2025)
- (2) Unit 2 (July 1, 2024, through June 30, 2025)
- (3) Unit 3 (July 1, 2024, through June 30, 2025)
MS09: Residual Heat Removal Systems (IP Section 02.08) (3 Samples)
- (1) Unit 1 (July 1, 2024, through June 30, 2025)
- (2) Unit 2 (July 1, 2024, through June 30, 2025)
- (3) Unit 3 (July 1, 2024, through June 30, 2025)
BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10) (3 Samples)
- (1) Unit 1 (July 1, 2024, through June 30, 2025)
- (2) Unit 2 (July 1, 2024, through June 30, 2025)
- (3) Unit 3 (July 1, 2024, through June 30, 2025)
71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (2) NCR 2563815 and NCR 2565805, discrepancy between emergency action level guidance and site technical specifications on the allowed concentration of Iodine-131
71153 - Follow-Up of Events and Notices of Enforcement Discretion Event Follow-up (IP Section 03.01)
- (1) The inspectors evaluated the excessive reactor coolant system leakage outside of containment on Unit 1 and the licensees response on September 10, 2025. Per IMC 0309, Reactive Inspection Decision Basis for Power Reactors, the NRC considered whether this inspection sample should be the subject of a reactive inspection and determined that a reactive inspection was not necessary, as documented in ML25258A143.
Personnel Performance (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated licensee performance during a Unit 3 asymmetric rod runback involving a dropped control rod during control rod drive breaker testing on July 21,
INSPECTION RESULTS
Improper Implementation of Letdown Filter Maintenance Resulting in Excessive RCS Leakage and a Notice of Unusual Event Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000269/2025003-01 Open/Closed
[H.12] - Avoid Complacency 71111.12 A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a, was identified for the licensees failure to implement the established procedure for replacement of the Unit 1 B train letdown filter, in accordance with Regulatory Guide 1.33, Revision 2, Appendix A, February 1978. Specifically, the licensee failed to perform maintenance on the intended component and instead altered the in-service Unit 1 A train letdown filter, resulting in a leak of approximately 26 gallons per minute (gpm) and a corresponding declaration of a Notice of an Unusual Event (NOUE).
Description:
On September 10, 2025, at approximately 11:33 am, the licensee began work to perform a letdown filter removal and replacement activity on the isolated Unit 1 B letdown filter via work order 20747819. In accordance with procedure MP/0/A/1600/005 B, Revision 041, Filter-Letdown Storage - Drum Method Removal and Replacement, licensee personnel began to loosen the eyebolts for the vessel of the letdown filter housing but failed to ensure they were performing maintenance on the correct component. Instead, personnel loosened eyebolts for the Unit 1 A train letdown filter, which remained in-service at the time.
At approximately 11:35 am, operators in the Unit 1 control room identified a decreasing level of the letdown storage tank (LDST). At approximately 11:38 am, personnel in the auxiliary building reported leakage from the 1A letdown filter housing to the control room operators.
Operators initiated makeup to the Unit 1 LDST and entered the abnormal procedure for excessive reactor coolant system (RCS) leakage. At 11:52 am, control room operators quantified the leakage as approximately 26 gpm, which was in excess of their criteria for a declaration of a NOUE due to identified RCS leakage greater than 25 gpm if it persists for greater than 15 minutes. The licensee began actions to isolate the 1A letdown filter and return the 1B letdown filter to service. At 12:07 pm, the licensee declared a NOUE for excessive RCS leakage (Event Notification 57914). However, leakage remained well within the licensees normal makeup capacity of 160 gpm. At 12:34 pm, the licensee declared the leak isolated and terminated the NOUE at 1:53 pm.
Corrective Actions: The licensee initiated cause investigation and performance analysis checklists to determine the cause of the event. Subsequent repairs of the Unit 1 A letdown filter housing were documented in work order (WO) 20748172.
Corrective Action References: CR 2567951, WO 20758172
Performance Assessment:
Performance Deficiency: The inspectors determined that the licensees failure to replace the filter on the correct component during maintenance in accordance with procedure MP/0/A/1600/005 B, Revision 041, Filter-Letdown Storage - Drum Method Removal and Replacement was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the performance deficiency resulted in RCS leakage greater than 25 gpm, for greater than 15 minutes, which required a NOUE declaration.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using IMC 0609 Exhibit 1, Initiating Events Screening Questions, inspectors determined the finding was of very low safety significance (Green), because this leakage could not reasonably be assessed to exceed the normal makeup capacity of the plant to respond to a small loss of coolant accident (LOCA), nor could this leakage be reasonably assessed to have affected other systems used to mitigate a LOCA.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, licensee personnel failed to recognize the latent issue of work being imminent on an incorrect component due to the proximity of the intended component.
Enforcement:
Violation: Technical Specification (TS) 5.4.1.a requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978. Section 3.n of Regulatory Guide 1.33, Revision 2, requires procedures associated with Chemical and Volume Control System (including Letdown/Purification System). The licensee established procedure MP/0/A/1600/005 B Filter - Letdown Storage - Drum Method - Removal and Replacement, Revision 41, for the purpose of controlling required periodic maintenance on the letdown system.
Contrary to the above, on September 10, 2025, the licensee failed to implement MP/0/A/1600/005 B Filter - Letdown Storage - Drum Method - Removal and Replacement, during planned maintenance to replace the Unit 1 B letdown filter. Specifically, the licensee mistakenly began maintenance activities on the in-service 1A letdown filter instead. This resulted in a leak from the Unit 1 A letdown filter housing, and a corresponding NOUE declaration.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Licensee-Identified Non-Cited Violation 71152A 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: 10 CFR 50.54(q)(2)(i) states, in part, that a holder of a nuclear power reactor license under this part shall follow and maintain the effectiveness of an emergency plan that meets the planning standards of 10 CFR 50.47(b). Planning Standard 10 CFR 50.47(b)(4)requires, in part, A standard emergency classification and action level scheme, the bases of which include facility system and effluent parameters, is in use by the nuclear facility licensee, and State and local response plans call for reliance on information provided by facility licensees for determinations of minimum initial offsite response measures.
Contrary to the above, since early 2017, the licensee failed to follow and maintain the effectiveness of an emergency plan that meets the planning standard 10 CFR 50.47(b)(4).
Specifically, both Revision 5 of wall chart CSD-EP-ONS-0101-02, Oconee Nuclear Station Classification of Emergency and Revision 7 of CSD-EP-NS-0101-01, EAL Technical Basis Document, which form the licensees emergency action level (EAL) scheme, contained incorrect directions that could lead to a failure to declare a Notice of Unusual Event (NOUE)when required. Detailed within CSD-EP-NS-0101-01 is SU4.1, the EAL for a NOUE initiated by reactor coolant activity greater than TS allowable limits. SU4.1 states, in part, that NOUE entry is required when activity is greater than TS allowable limits, specifically referencing Condition C of LCO 3.4.11, RCS Specific Activity. The EAL guidance directs the licensee to declare a NOUE when the concentration of Dose Equivalent Iodine-131 (DEI) is greater than 50 µCi/gm for a continuous period of over 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. However, this is less restrictive than Technical Specification (TS) allowable limits. TS 3.4.11 prohibits the concentration of DEI in the RCS from rising above 50 micro-curies per gram (µCi/gm) at any time or from being above 1.0 µCi/gm for a continuous period of over 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
Significance/Severity: Green. Using Inspection Manual Chapter (IMC) 0609 Attachment 4, Initial Characterization of Findings, this issue adversely affects the Emergency Preparedness cornerstone since it is a failure to comply with a planning standard. Per Table 3, the inspector is directed to IMC 0609, Appendix B, Emergency Preparedness Significance Determination Process. Section 5.4, 10 CFR 50.47(b)(4), Emergency Classification System, directs that procedure issues that render EALs ineffective such that a NOUE would not be declared, or declared in a degraded manner for a particular off-normal event, are of very low safety significance, or Green.
Corrective Action References: NCR 2565805, NCR 2558345; The licensee has revised the applicable procedures and corresponding wall chart.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 8, 2025, the inspectors presented the integrated inspection results to Steven Snider and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
2563889
KEE-111
Elementary Diagram Turbine and Governor Systems Startup
Control
Drawings
KEE-113
Elementary Diagram Master Control System Startup
Controls
Clearance PRT-0-25-230 YEL BUS-0171
Clearance PRT-K1-25-K2OHOOS-0172
Miscellaneous
OSS-0254.00-00-
2005
(ELECT) Keowee Emergency Power Design Basis
Document
037
Work Orders
20708694
OSC-9314
NFPA 805 Transition Risk-Informed Performance-Based
Fire Risk Evaluation
006
OSC-9375
ONS Fire PRA - Fire Scenario Report
2
Calculations
OSC-9659
Oconee Nuclear Safety Capability Assessment for Units 1,
2, and 3
011
Corrective Action
Documents
23274, 2281612, 2330914, 2274272
CSD-ONS-PFP-
Pre-Fire Plan for U1 Auxiliary Building Elevation 809
CSD-ONS-PFP-
Pre-Fire Plan for U1 Auxiliary Building Elevation 822
000
CSD-ONS-PFP-
Pre-Fire Plan for U2 Turbine Building Elevation 775
001
Fire Plans
CSD-ONS-PFP-
Pre-Fire Plan for U3 Turbine Building Elevation 796
000
CSD-ONS-FS-
20
SOG Fire Strategy Guideline 20 Key Equipment List By Fire
Zone
000
O-0310-FZ-012
Auxiliary Building - Unit 1 Fire Protection Plan Fire Area &
Fire Zone Boundaries Plan at EL 809+3
Miscellaneous
O-0310-FZ-015
Auxiliary & Reactor Building - Units 1 Fire Protection Plan
Fire Area & Fire Zone Boundaries Plan at EL 822+0 &
003
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
25+0
O-0310-FZ-016
Auxiliary & Reactor Building - Units 2 Fire Protection Plan
Fire Area & Fire Zone Boundaries Plan at EL 822+0 &
25+0
004
O-0310-K-10
Auxiliary Building - Unit 1 Fire Protection Plan & Fire Barrier,
Flood, & Pressure Boundaries Plan at EL 809+3
O-0310-K-13
Fire Protect Aux Bldg Unit 1 EL 822+0
015
O-0310-K-14
Aux & Reactor Building Unit 2 Fire Protect Plan & Fire
Barrier, Flood & Pressure Boundaries Plan at EL 822+0 &
25+0
019
O-0310-L-002
Turbine Building - Unit 2 - Fire Barriers, Flood, & Pressure
Boundaries Plan at EL 775+0
OM 280.--
23.001
Fire Protection Design Basis Document Appendicies A, B, &
G
25
Calculations
OSC-11956
RBCU Test Evaluation
019
Corrective Action
Documents
2386632, 2478640, 2551975, 2461016
ONEI-0400-400
Revised Reactor Building Cooling Unit Requirements in
Support of 1-Year Mission Times
003
Miscellaneous
OSS-0254.00-00-
26
(MECH) Reactor Building Cooling System Design Basis
Document
047
Procedures
PT/0/A/0160/006
Reactor Building Cooling Units Performance Test
045
Corrective Action
Documents
2562053
Miscellaneous
ASE-35
Simulator Exercise Guide
03a
Procedures
AP/3/A/1700/001
Unit Runback
20
Corrective Action
Documents
2538150, 2567951, 2569554, 2569552
Drawings
OFD-124A-01-01
Flow Diagram of Low Pressure Service Water System
Turbine Building (Low Pressure Service Water Pumps)
056
Miscellaneous
OSS-0254.00-00-
1039
(MECH) Design Basis Specification for the Low Pressure
Service Water System
069
AD-EG-ALL-1210
Procedures
MP/0A/1600/005
Filter - Letdown Storage - Drum Method - Removal and
041
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
B
Replacement
TE-MN-ALL-002
Foreign Material Exclusion Level And Controls Screening
Work Orders
20700430
Corrective Action
Documents
2548087
Drawings
OFD-102A-3.2
Flow Diagram of Low Pressure Injection System (LPI Pump
Discharge)
Miscellaneous
Risk Profile for Unit 3 for the week of July 7th, 2025
AD-NF-ALL-0501
Electronic Risk Assessment Tool (ERAT)
AD-OP-ALL-0400
Operations Work Management - Online
2
AD-WC-ALL-0240
On-line Work Management Process
Procedures
AD-WC-ALL-0250
Work Implementation and Completion
018
Calculations
OSC-6550
Hydraulic Model of Condenser Service Water for Chillers A
and B
Corrective Action
Documents
2544935, 2566197, 2564496, 2546416, 2567168
O-6700
One-Line Diagram, Main PSW Switchgear, 13.8 / 4.16 kV
System
015
Drawings
OFD-133A-01-01
Flow Diagram of Condenser Circulating Water System
(CCW Intake Pumps Discharge)
038
Engineering
Changes
114921
OM-322-0106.009
Nutherm Qualification Report for PSW System 5kV Motor
Operated Manual Transfer Switch P/N 72086
OSS-0254.00-00-
1001
(MECH) High Pressure Injection and Purification &
Deborating Demineralizer Systems
071
OSS-0254.00-00-
1003
(MECH) Condenser Circulating Water (CCW) System
047
Miscellaneous
OSS-0254.00-00-
1053
Protected Service Water System
009
AD-EG-ALL-1612
Environmental Qualification (EQ) Program
009
IP/0/A/0401/002
KHU-1 And 2 TXS Governor Control System, Generator
Speed Sensor Input String Test
Procedures
OP/0/A/1650/006
PSW DC Power
2
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
OP/1/A/1104/004
Low Pressure Injection System
166
PT/0/A/0261/015
Chiller Condenser Service Water Pump Test
017
Work Orders
WOs 20680685, 20710309, 20293394, 20746223, WR 289785, NCR 2558007
OSC-10361
Minimum Short Circuit Currents for SSF Fed Pressurizer
Heaters
004
Calculations
OSC-5093
SSF AC Power System Voltage and Short Circuit Study
017
Corrective Action
Documents
2514566
Drawings
ONTC-0-135A-
0001-001
SSF DG Voltage and Frequency Range Test Acceptance
Criteria
Engineering
Changes
20621
OSS-0254.00-00-
2014
(ELECT) Design Basis Document for the 4160/600/120V
SSF Essential AC Power System
20
Miscellaneous
OSS-0351.00-00-
0014
Replacement of Emergency Diesel Generator Voltage
Regulator
IP/0/A/2005/004
ESI Current Boost CSBE Static Exciter Voltage Regulator
Exciter System
019
PT/0/A/0400/011
SSF Diesel Generator Test
016
Procedures
PT/0/A/0600/021
Standby Shutdown Facility Diesel - Generator Operation
018
Work Orders
20521411
Corrective Action
Documents
2561298, 02565276
OSS-0254.00-00-
28
(MECH) Design Basis Spec for the Low Pressure Injection
and Core Flood System (LPI)
075
Miscellaneous
OSS-0254.00-00-
2004
(ELECT) 230 KV Switchyard System
27
IP/0/B/035/004
CRD System Checkout Prior To Maintenance/Testing
27
IP/3/A/0315/014A
TXS RPS Interposing Relay Test And Control Rod Drive
Breaker Trip Timing Test
011
OP/0/A/2000/014
KHU-2 Generator
OP/0/A/2000/041
KHS - Modes of Operation
Procedures
PT/0/A/0500/020
PSW Power Path Test
018
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
PT/0/A/0610/002
External Grid Trouble Protective System Logic and
Switchyard Isolation Logic Test
2
PT/0/A/0620/009
Keowee Hydro Operation
056
PT/2/A/0203/006
A
Low Pressure Injection Pump Test - Recirculation
PT/2/A/0600/013
Motor-Driven Emergency Feedwater Pump Test
PT/2/A/2200/003
KHU-2 Semi-Annual Surveillance
PT/3/A/0203/006A
Low Pressure Injection Pump Test - Recirculation
097
Work Orders
WOs 20732578, 20734631, 20733906
WRs 20291666, 20681930, 20616466, 20728455, 20728455
Duke Energy Common Emergency Plan
Miscellaneous
MSEL 25-03
ONS Drill 25-03
Corrective Action
Documents
2516052, 2565805, 2558345, 2563815
Drawings
OFD-124A-01-01
Flow Diagram of Low Pressure Service Water System
Turbine Building (Low Pressure Service Water Pumps)
056
Miscellaneous
OSS-0254.00-00-
1039
(MECH) Design Basis Specification for the Low Pressure
Service Water System
069
CSD-EP-ONS-
0101-01
EAL Technical Basis Document
007
CSD-EP-ONS-
0101-02
Oconee Nuclear Station Classification of Emergency
005
CSD-EP-ONS-
0101-03
Emergency Action Level Reference Manual
Procedures
MP/0/A/1840/040
Pumps - Motors - Miscellaneous Components - Lubrication
- Oil Sampling - Oil Change
041
Corrective Action
Documents
2562053, 2567951, 2567939, 2567990, 2567951
OFD-101A-1.2
Flow Diagram of High Pressure Injection System (Storage
Section)
43C
OFD-116G-1.1
Flow Diagram of Auxiliary Building Ventilation System
Basement, 1st, 2nd, 3rd, and 4th Floors
Drawings
OFD-116G-1.2
Flow Diagram of Auxiliary Building Ventilation System 5th
and 6th Floors
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
OFD-116G-1.4
Flow Diagram of Auxiliary Building Ventilation System Vent
Stacks
OM 2201.M-
0305.001
DCRDCS Output Cabinet No. 3 Output Assembly Terminal
Board Layout and Wiring
D4
201.M-0401.001
DCRDCS Instruction Manual
D06
ONEI-0400-0598
Oconee 3 Cycle 33 Core Operating Limits Report
Miscellaneous
OSS-0254.00-00-
2013
Design Basis Specification for the Control Rod Drive System
AD-EP-ALL-0101
Emergency Classification
AP/1/A/1700/002
Excessive RCS Leakage
018
AP/1/A/1700/018
Abnormal Release of Radioactivity
25
AP/3/A/1700/001
Unit Runback
Procedures
CSD-EP-ONS-
0101-01
EAL Technical Basis Document
007
Work Orders
20747819