IR 05000498/2025003
| ML25345A291 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 12/19/2025 |
| From: | Douglas Dodson NRC/RGN-IV/DORS/PBC |
| To: | Kharrl C South Texas |
| References | |
| IR 2025003 | |
| Download: ML25345A291 (0) | |
Text
December 19, 2025
SUBJECT:
SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000498/2025003 AND 05000499/2025003
Dear Charles Kharrl:
On September 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at South Texas Project Electric Generating Station, Units 1 and 2. On December 10, 2025, the NRC inspectors discussed the results of this inspection with Robert Norris, Site Vice President, 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.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; the Director, Office of Enforcement; and the NRC Resident Inspector at South Texas Project Electric Generating Station, Units 1 and 2. If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; and the NRC Resident Inspector at South Texas Project Electric Generating Station, Units 1 and 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, Douglas E. Dodson II, Chief Reactor Projects Branch C Division of Operating Reactor Safety Docket Nos. 05000498 and 05000499 License Nos. NPF-76 and NPF-80
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000498 and 05000499
License Numbers:
Report Numbers:
05000498/2025003 and 05000499/2025003
Enterprise Identifier:
I-2025-003-0011
Licensee:
STP Nuclear Operating Company
Facility:
South Texas Project Electric Generating Station, Units 1 and 2
Location:
Wadsworth, TX 77483
Inspection Dates:
July 1, 2025, to September 30, 2025
Inspectors:
J. Brodlowicz, Resident Inspector
L. Flores, Resident Inspector
S. Graves, Senior Reactor Inspector
M. Hayes, Senior Resident Inspector
G. Kolcum, Senior Resident Inspector
S. Lichvar, Technical Assistant
E. Powell, Senior Resident Inspector
K. Smetana, Resident Inspector
J. Vera, Senior Resident Inspector
Approved By:
Douglas E. Dodson II, Chief
Reactor Projects Branch C
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at South Texas Project Electric Generating Station, Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
Failure to Follow Maintenance Instructions Results in Inoperable Pressurizer Power-Operated Relief Valve Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000498/2025003-01 Open/Closed
[P.2] -
Evaluation 71153 The inspectors identified a Green finding and associated NCV of Technical Specification 6.8.1.a for the licensees failure to adhere to maintenance instructions during troubleshooting of pressurizer power operated relief valve (PORV) PCV-0656A in accordance with Regulatory Guide 1.33, Quality Assurance Program Requirements (Operation), Revision 2, Appendix A,
Section 9, Procedures for Performing Maintenance. Specifically, in 2024 during forced outage 1F2401, the licensee failed to follow work instructions that directed replacing a solenoid valve assembly. As a result, pressurizer PORV PCV-0656A was inoperable for greater than its allowed technical specification outage time.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000498/2024-006-00 Unit 1, Condition Prohibited by Technical Specifications and Potential Loss of Safety Function Due to Inoperable Pressurizer Power-Operated Relief Valve 71153 Closed LER 05000498/2024-007-01 Unit 1, Supplement to Condition Prohibited by Technical Specifications 71153 Closed
PLANT STATUS
Both units began the inspection period at rated thermal power and operated at or near rated thermal power for the remainder of the inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed onsite 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) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 1, class 1E 125 VDC battery walkdowns on July 23, 2025
- (2) Unit 2, class 1E 125 VDC battery walkdowns on July 23, 2025
- (3) Unit 1, train B essential chilled water system on September 18, 2025
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the safety injection system on July 8, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
- (1) Unit 1, auxiliary shutdown area on July 24, 2025
- (2) Unit 1, train A, B, and C essential cooling water intake structure on August 5, 2025
- (3) Unit 2, train A, B, and C essential cooling water intake structure on August 7, 2025
- (4) Unit 1, train A and B spent fuel pool pumps and heat exchanger rooms on August 28, 2025
- (5) Unit 2, train A and B spent fuel pool pumps and heat exchanger rooms on August 28, 2025
- (6) Unit 1, train C essential chiller and component cooling water pump room on September 17, 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, train B safety-related heat exchanger health following essential cooling water strainer bypass flow
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 1 replacement of the 1D steam generator program level control card on September 8, 2025
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated Unit 2 just-in-time training on September 23, 2025, for shutdown and cooldown before refueling outage 2RE24.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components remain capable of performing their intended function:
- (1) Unit 1, engineered safety features actuation system power supply failures on July 24, 2025
- (2) Unit 1, train C essential chiller failure to maintain outlet temperature when it exceeded 52 degrees on August 9, 2025
- (3) Unit 2, train A essential cooling water traveling screen failure to start due to relay failure on August 22, 2025
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (3 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, yellow risk for train A essential cooling water, component cooling water, essential chilled water, and emergency diesel generator planned outage the week of July 28, 2025
- (2) Unit 1, yellow risk for train C essential cooling water planned maintenance the week of August 11, 2025
- (3) Unit 1, yellow risk and risk management actions for planned maintenance on train C essential cooling water system the week of August 25, 2025
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Unit 1 and Unit 2, train D auxiliary feedwater system crossover valves alternative gasket design on July 11, 2025
- (2) Unit 1 and Unit 2, class 1E inverters after 10 CFR Part 21 notification on July 14, 2025
- (3) Unit 1 and Unit 2, train C essential cooling water sump after discovery of structural support degradation on July 17, 2025
- (4) Unit 1, class 1E DC batteries when cracks were identified on July 25, 2025
- (5) Unit 2, train A essential chiller after high compressor discharge temperature on September 24, 2025
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) Unit 2, train A essential chiller after replacement of 16R relay and high compressor discharge temperature switch on August 19, 2025
- (2) Unit 2, emergency safety feature actuation system after thumbwheel timing switch replacement on August 22, 2025
- (3) Unit 2, train A essential chiller after high compressor discharge temperature on September 6, 2025
- (4) Unit 2, train A safety injection system contaminated system leakage test on September 25, 2025
- (5) Unit 2, train A low head and high head safety injection pump test on September 25, 2025
Surveillance Testing (IP Section 03.01) (2 Samples)
- (1) Unit 1, train C emergency diesel generator on August 26, 2025
- (2) Unit 2, train C emergency diesel generator on September 16, 2025
71114.06 - Drill Evaluation
Required Emergency Preparedness Drill (1 Sample)
- (1) The inspectors evaluated a full site integrated drill involving a steam generator tube rupture and unisolable main steam line break resulting in a general emergency on July 24, 2025
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
(1)crew 1E full site integrated drill involving a control rod ejection, loss of coolant and fission product release resulting in a general emergency on September 10,
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)
MS07: High Pressure Injection Systems (IP Section 02.06) (2 Samples)
- (1) Unit 1 (July 1, 2024, through June 30, 2025)
- (2) Unit 2 (July 1, 2024, through June 30, 2025)
MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)
- (1) Unit 1 (July 1, 2024, through June 30, 2025)
- (2) Unit 2 (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:
- (1) Unit 1 and Unit 2, qualified processing display system recent failures on August 8, 2025
- (2) Unit 1, train D auxiliary feedwater pump overspeed and condensate accumulation in piping coming out of 1RE25 on August 10, 2025
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 05000498/2024-006-00, "Unit 1, Condition Prohibited by Technical Specifications and Potential Loss of Safety Function Due to Inoperable Pressurizer Power-Operated Relief Valve" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24358A097). The inspection conclusions associated with this LER are documented in this report under Inspection Results Section 71153. This LER is Closed.
- (2) LER 05000498/2024-007-01, "Unit 1, Supplement to Condition Prohibited by Technical Specifications" (ML25163A305). The inspection conclusions associated with this LER are documented in NRC Inspection Report 05000498/2025001 and 05000499/2025001, dated April 17, 2025, under Inspection Results Section 71153.
This LER is Closed.
INSPECTION RESULTS
Failure to Follow Maintenance Instructions Results in Inoperable Pressurizer Power-Operated Relief Valve Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000498/2025003-01 Open/Closed
[P.2] -
Evaluation 71153 The inspectors identified a Green finding and associated NCV of Technical Specification 6.8.1.a for the licensees failure to adhere to maintenance instructions during troubleshooting of pressurizer power operated relief valve (PORV) PCV-0656A in accordance with Regulatory Guide 1.33, Quality Assurance Program Requirements (Operation), Revision 2, Appendix A, Section 9, Procedures for Performing Maintenance. Specifically, in 2024 during forced outage 1F2401, the licensee failed to follow work instructions that directed replacing a solenoid valve assembly. As a result, pressurizer PORV PCV-0656A was inoperable for greater than its allowed technical specification outage time.
Description:
Pressurizer power-operated relief valve PCV-0656A is one of two safety-related valves used to relieve primary pressure during a primary feed and bleed event scenario and is required to operate multiple times during a loss of coolant accident, small break loss of coolant accident, steam generator tube rupture and other design basis accidents. It is a pressure-actuated relief valve controlled by a solenoid valve and can be operated from the control room or the auxiliary shutdown panel (ASP) by using a switch to transfer control to the appropriate location.
The solenoid was installed in October 2021 during 1RE23 following the failure of PORV PCV-0656A to stroke for surveillance testing. The licensee completed corrective maintenance on PORV PCV-0656A on November 1, 2021, but excessive seat leakage was again noted during ascension to Mode 3, and its block valve was closed for the remainder of the cycle.
PORV PCV-0656A was subsequently reworked in March 2023 during 1RE24 when the licensee again performed corrective maintenance to address PORV PCV-0656A valve seat leakage. The solenoid valve assembly was leak tested but was not replaced.
On February 29, 2024, during forced outage 1F2402, PORV PCV-0656A failed to open during surveillance testing from both the control room and the ASP. The licensee declared PORV PCV-0656A inoperable and performed troubleshooting on March 1, 2024, under Work Authorization Number (WAN) 686448. The licensee measured as-found voltage and current for the solenoid coil while attempting to open PORV PCV-0656A and found electrical current for the solenoid coil to be 0.00 amps. WAN 686448 states in a note to step 3.4, current measuring less than one amp or greater than 9 amps indicates the need to replace the solenoid valve assembly. Further, step 3.4.2 of WAN 686448 states, in part, that if current readings are not satisfactory, replacement of the solenoid assembly is required. However, as the licensee continued performing additional electrical testing of wired connections, the personnel performing the troubleshooting came to the conclusion that the problem must be between the transfer switch, HS-0656C, and the solenoid, due to varying resistance readings while manipulating the switch. The licensee identified that two of four bolts on the control room/ASP transfer switch were loose and replaced the switch; however, the inspectors noted that the steps directing replacement of the solenoid assembly were documented as not applicable, and it was not replaced.
On October 4, 2024, while in Mode 3, Unit 1 pressurizer PORV PCV-0656A failed to open from the control room hand switch and ASP hand switch during performance of a required surveillance test. The licensee performed troubleshooting and identified a partially disengaged fastener that connects the wire from the PORV solenoid to its power source within the solenoid housing in the reactor containment building. The loose fastener resulted in an intermittent loss of the wired connection, preventing the solenoid from energizing to allow operation of the valve. After tightening the loose fastener, post-maintenance testing was performed, and the PORV was returned to operable on November 5, 2024.
The licensee performed an operability evaluation and determined that the PORV had been inoperable since its installation on November 1, 2021, for two operating cycles.
Corrective Actions: The licensee tightened the loose wiring connection, completed an extent of condition for Unit 1 PORV PCV-0655A and warehouse spares. Further extent of condition for Unit 2 PORVs was performed during refueling outage 2RE24 with satisfactory results.
Additionally, the licensee has added instructions in maintenance procedures to check tightness of the fastener any time the solenoid cover is removed.
Corrective Action References: CR 2024-9592 and CR 2024-2037
Performance Assessment:
Performance Deficiency: The failure to follow work instructions documented in WAN 686448, as required by Technical Specification 6.8.1.a, while performing troubleshooting on PORV PCV-0656A was a performance deficiency. Specifically, the licensee failed to follow the steps in the work instructions directing replacement of the solenoid assembly when the measured current was not satisfactory.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the presence of the loose connection in the solenoid housing resulted in intermittent loss of the wired connection that would prevent the solenoid from energizing and thus did not provide reasonable assurance that PORV PCV-0656A would operate when required.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 2, Mitigating Systems Screening Questions, dated January 1, 2021. The inspectors determined that this finding required a detailed risk evaluation because the inoperability of PORV PCV-0656A represented a loss of PRA function for one train of a multi-train system for greater than its technical specification allowed outage time. The inspectors referenced a detailed risk evaluation that was previously performed by a Senior Reactor Analyst and documented in NRC Inspection Report 05000498/2023003 and 05000499/2023003 for the Unit 1 pressurizer PORV PCV-0656A being in a condition where it would have been unable to perform its required function of opening on demand throughout an operating cycle using the maximum exposure time of 1 year.
The Senior Reactor Analyst concluded that the safety significance of this finding is bounded by the results of the previous analysis, which included best estimates of 7.8E-7/year for total delta-CDF and 6.0E-8/year for total delta-LERF. Therefore, this finding was determined to be of very low safety significance (Green).
Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, the licensee did not thoroughly investigate the failure of PORV PCV-0656A to operate when work instruction steps that directed replacement of a solenoid were documented as not applicable during troubleshooting after subsequent troubleshooting identified loose bolts on a transfer switch. As a result, only the transfer switch was replaced.
Enforcement:
Violation: Technical Specification 6.8.1.a requires, in part, that written procedures shall be established, implemented, and maintained in accordance with Regulatory Guide 1.33, Revision 2, Appendix A, Section 9, "Procedures for Performing Maintenance." Regulatory Guide 1.33, Revision 2, requires, in part, that maintenance that can affect the performance of safety-related equipment should be properly pre-planned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances.
Technical Specification 3.4.4, Relief Valves, requires, in part, that both PORVs and their associated block valves shall be operable in Modes 1, 2, and 3. Technical Specification 3.4.4 action statement
- (b) requires, in part, that with one PORV inoperable due to causes other than excessive seat leakage, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> either restore the PORV to operable status or close the associated block valve and remove power from the block valve; within the following 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> restore the PORV to operable status or be in hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in hot shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Contrary to the above, on March 1, 2024, for maintenance that can affect the performance of safety-related equipment, the licensee failed to perform maintenance in accordance with written procedures appropriate to the circumstances. Specifically, the licensee documented that work instruction steps were not applicable that directed replacement of a solenoid assembly for PORV PCV-0656A when electrical current testing indicated the need to replace it during performance of troubleshooting on PORV PCV-0656A. As a result, from November 1, 2021, until November 5, 2024, PORV PCV-0656A was inoperable for greater than the allowed outage time permitted by Technical Specification 3.4.4 action
- (b) for one PORV inoperable due to causes other than excessive seat leakage, and the unit was not placed in hot standby within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 10, 2025, the inspectors presented the integrated inspection results to Robert Norris, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
AC Electrical Distribution Breaker Lineup
Transformer Normal Breaker and Switch Lineup
Essential Chilled Water System
Safety Injection System Initial Lineup
Procedures
Switchgear E1A(E2A) Bus Outage
Fire Preplan Electrical Auxiliary Building, Auxiliary Shutdown
Area
Fire Preplan Fuel Handling Building Spent Pool Aux Area
Fire Preplan Fuel Handling Building Spent Fuel Pool Heat
Exchanger A
Fire Preplan Fuel Handling Building Spent Fuel Pool Heat
Exchanger B
Fire Preplan Mechanical Auxiliary Building CCW Pump and
Chiller, Train C
0600
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train A
0601
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train B
0602
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train C
0603
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train C
0604
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train B
Fire Plans
0605
Fire Preplan Essential Cooling Water Intake Structure Pump
Room Train A
Calculations
MC-6255
SBDG Intercooler Performance
Procedures
Essential Cooling Water Reliability Program
Work Orders
Work
Authorization
Number
468992, 427708, 508549, 544989, 582208, 674112, 231584,
348114, 443062, 466411, 507829, 661040, 663987, 670543
Procedures
Plant Shutdown from 100% to Hot Standby
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Plant Cooldown
101
Corrective Action
Documents
CR-YYYY-NNNN
25-2468, 2025-6643, 2025-6832, 2023-9788, 2024-0113,
25-0106
Drawings
0363-0050
Functional Block Diagram South Texas Project ESF Load
Sequencer
04/27/1987
25-6643 Fault
Tree
Essential Chiller 12C Fault Tree/Evidence and Action Matrix
07/31/2025
25-6832-2
Rework Evaluation Worksheet for ECW Traveling Screen 2A
08/14/2025
Defer-24-330853
Deferral of WAN 633559 ESF Load Sequencer Cabinet B
(3N091ZLP802) Replace PS1, PS2 and 5VDC Power
Supplies EOGP 06/04/2024
04/30/2024
Fix-It-Now Team
Guideline FIN-
0001
Essential Chiller Temperature Control Loop As-Found
Checklist
07/28/2025
Prompt
Equipment
Performance
Checklist
23-9788 ESF Load Sequencer 1C Power Supply failure
2/12/2023
Miscellaneous
STP-97053
Failure Analysis of DC to DC Power Supply
04/18/2025
Work Orders
Work
Authorization
Number
633559, 697363, 707560
Miscellaneous
DTL No:1008789
Unit 1, STP-RICTCal for Work Week 33
RA Seq No1: 4812
08/27/2025
Procedures
Risk Management Actions (RMAs)
Corrective Action
Documents
CR-YYYY-NNNN
22-993, 2023-10129, 2025-3607, 2025-754, 2025-3591,
25-5706, 2025-6367
25-5706-1
Evaluation of Gasket Design Enhancement for Cross Connect
Valves
06/26/2025
5R289MB01006
Design Basis Document: Essential Cooling Water System
Document
Change Notice
0801233, 1002244, 1200768, 1201407, 1400798, 2200329
Miscellaneous
VTD-A363-0021
Vendor Technical Document for Instruction and Operating
Manual for 10 KVA Inverter
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
VTD-Y018-0014
Installation, Operation, and Maintenance Instructions for York
Model OTK5CI-IMCS Open Turbopak Centrifugal Liquid
Chilling Units
Operability
Evaluations
25-6367-1
Tier 1 Operability or Reportability Review for Class 1E 125
VDC Batteries
07/25/2025
CFR 50.59 Evaluations
Procedures
Essential Chiller Operation
Work Orders
Work
Authorization
Number
593316, 593317, 612253, 612254, 636265, 636266, 636994,
2815, 644913, 723500
Corrective Action
Documents
CR-YYYY-NNNN
21-9155, 2025-7185, 25-6845, 25-7221, 25-6836, 24-7620
Drawings
8310-00011YD
Wiring Diagram York Turbopak Nema 12
L
Essential Chiller Operation
Standby Diesel 13(23) Operability Test
Low Head Safety Injection Pump 1A(2A) Inservice Test
High Head Safety Injection Pump 1A(2A) Inservice Test
Procedures
Safety Injection System Train 1A/2A Contaminated System
Leakage Test
Work Orders
Work
Authorization
Number
731309, 677051, 676533, 685380
Corrective Action
Documents
CR-YYYY-NNNN
25-6443, 2025-6448, 2025-6450
Emergency Notifications
Procedures
EAL Wall Charts
MSPI Bases Document
Preparation and Submittal of NRC Performance Indicators
71151
Procedures
SEG-0007
Mitigating System Performance Indicator Collection,
Processing and Maintenance of Data
Corrective Action
Documents
CR-YYYY-NNNN
25-6243, 2025-6242, 2025-6240, 2025-6234, 2025-6182,
25-6168, 2024-11088, 2025-6067
Corrective Action
Documents
CR-YYYY-NNNN
25-6795
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Resulting from
Inspection
24-10685
Common Cause for Steam Generator PORVs
Miscellaneous
24-4879
Root Cause Evaluation: Failure of SG PORV 2C
0001
AMSAC Actuation Test Trains A, B, C, & D
Auxiliary Feedwater Pump 14(24) Inservice Test
Procedures
SEG-0008
Printed Circuit Board Maintenance and Replacement
Guideline
Work Orders
Work
Authorization
Number
665364, 666434, 683837, 717068
Corrective Action
Documents
CR-YYYY-NNNN
24-9592, 20-8152
Miscellaneous
VTD-C710-0008
Instruction Manual, Operation and Maintenance Instructions
for Solenoid Powered Operated Relief Valve
Control of Configuration Changes
Cable Terminations
28
Pressurizer Power Operated Relief Valve Maintenance
Switchgear E1B(E2B) Bus Outage
Procedures
MG-0009
Maintenance Fundamentals
Work Orders
Work
Authorization
Number
637822, 436899