IR 05000275/2022004
| ML23031A137 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 02/02/2023 |
| From: | Harry Freeman NRC/RGN-IV/DORS/PBA |
| To: | Gerfen P Pacific Gas & Electric Co |
| References | |
| IR 2022004 | |
| Download: ML23031A137 (25) | |
Text
February 02, 2023
SUBJECT:
DIABLO CANYON POWER PLANT, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000275/2022004 AND 05000323/2022004
Dear Paula A. Gerfen:
On December 31, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Diablo Canyon Power Plant, Units 1 and 2. On January 5, 2023, the NRC inspectors discussed the results of this inspection with you and other members of your staff.
The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding 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 Diablo Canyon Power Plant, 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 Diablo Canyon Power Plant, 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, Patricia J. Vossmar, Chief Projects Branch A Division of Operating Reactor Safety Docket Nos. 05000275, 05000323 License Nos. DPR-80, DPR-82
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000275 and 05000323
License Numbers:
Report Numbers:
05000275/2022004 and 05000323/2022004
Enterprise Identifier:
I-2022-004-0008
Licensee:
Pacific Gas and Electric Company
Facility:
Diablo Canyon Power Plant, Units 1 and 2
Location:
Avila Beach, CA
Inspection Dates:
October 1, 2022, to December 31, 2022
Inspectors:
A. Athar, Resident Inspector
H. Freeman, Senior Project Engineer
M. Hayes, Senior Resident Inspector
N. Hernandez, Operations Engineer
R. Kopriva, Senior Reactor Inspector
S. Lichvar, Project Engineer
S. Makor, Reactor Inspector
Approved By:
Patricia J. Vossmar, Chief
Projects Branch A
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Diablo Canyon Power Plant, 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
Inadequate Testing of the Incipient Fire Detector System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000275,05000323/2022004-01 Open/Closed
[P.2] -
Evaluation 71111.15 The inspectors identified a Green, non-cited violation of Unit 1 License Condition 2.C(5) and Unit 2 License Condition 2.C(4), Fire Protection, for the licensees failure to implement and maintain in effect all provisions of the approved fire protection program. Specifically, the licensees approved fire protection program required the testing of the incipient fire detection system airflow annually. The licensees maintenance testing and procedure for the incipient fire detection system did not conduct annual flow testing to verify adequate airflow through all ports or points to ensure that none of the sample lines were blocked.
Additional Tracking Items
Type Issue Number Title Report Section Status URI 05000323/2022004-02 Residual Heat Removal Suction Isolation Valve Leakage 71111.19 Open
PLANT STATUS
Unit 1 operated at or near rated thermal power for the entire inspection period.
Unit 2 began the inspection period at rated thermal power. On October 15, 2022, the unit was shut down to enter planned refueling outage 23. On November 23, 2022, the unit began a controlled power ascension, and returned to full power on November 27, 2022. Unit 2 remained 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 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) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 1 condensate booster system while condensate booster pump 1-3 out of service on October 3, 2022
- (2) Unit 2 reactor vessel refueling level indication system on October 18, 2022
- (3) Unit 1 containment spray system on November 15, 2022
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the Unit 2 emergency diesel generator 2-3 system on December 29, 2022.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (2 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 2 containment, 140-foot elevation, on November 10, 2022
- (2) Unit 2 turbine building, 119 and 104-foot elevations, on November 16, 2022
71111.06 - Flood Protection Measures
Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)
The inspectors evaluated internal flooding mitigation protections in the:
- (1) Units 1 and 2 cable spreading room air conditioning system on December 13, 2022
71111.08P - Inservice Inspection Activities (PWR) PWR Inservice Inspection Activities Sample - Nondestructive Examination and Welding Activities (IP Section 03.01)
- (1) The inspectors verified that the reactor coolant system boundary, steam generator tubes, reactor vessel internals, risk-significant piping system boundaries, and containment boundary are appropriately monitored for degradation and that repairs and replacements were appropriately fabricated, examined, and accepted by reviewing the following activities from October 17, 2022, through November 2, 2022:
03.01.a - Nondestructive Examination and Welding Activities
Dye Penetrant Examination: Notification: 51167081, Component - Line 1140 Welds: WIB-975H, WIB-975J, WIB-975K, (TGC2_69-22140.DOC 0305.1352)
Dye Penetrant Examination: Notification: 51139364, Component - FW-2-FCV-510 Valve Stem, (FW-2-FCV-510_ValveStem.doc 1103.0858)
Dye Penetrant Examination: Notification: 51167081, Component - Line 1140 Welds: WIB-975A, WIB-975B, WIB-975C, WIB-975E, WIB-975F, and WIB-975G, (PT Line 1140 EOC Part 2 TGC2_69-22140.doc 1025.0310)
Dye Penetrant Examination: Notification: 51169288, Component - WIB-975D Post Weld Overlay, Order -Operation 60148506-0040, (WIB-975D Post Weld Overlay PT 10-31-22.doc 1031.2021)
Dye Penetrant Examination: Notification: 51169288, Component - WIB-975D Post Weld Overlay, Order -Operation 60148506-0130, (PT Re-Inspect of Weld WIB-975D.doc 1102.2150)
Ultrasonic Examination: UT, Pressurizer Spray Line Nozzle to Shell Weld WIB-346, (WIB-346 Indication TGC_69-22182.doc 1027.0300)
Ultrasonic Examination: UT. Pressurizer Safety Valve Nozzle to Shell Weld WIB-422A, (WIB-422A TGC2_69-22181.doc 1026.0001)
Visual Examination: VT-1, Bottom Mounted Instrument penetrations examination, ISI X-CEDM, Revision 8, Dated 11/06/2022. (ISI X-CRDMu3r08.DOC 0914.0805)
Visual Examination: VT-1, Seal Table Thimble Tube Penetration Examination, Weld and tube above weld. (VT-1 10-18-22 Seal Table.doc 1027.0719)
Visual Examination: VT-2, Reactor Coolant System Hot Legs Inspection, Order 64150301-0100, (2R23 HL Exams.doc 1106.1254)
Visual Examination: VT-3, Line #S1-1663-8. Support ID: 77-7SL.
Drawing 051401, (77-7SL VT3 1028.1057)
Visual Examination: VT-3, Line #S1-512-14III. Support ID: 46-1V.
Drawing 051347, (46-1V VT3 1028.1112)
Visual Examination: VT-3, Line #S1-112-8. Support ID: 22-10V.
Drawing 051358, (22-10V VT3 1028.1104)
Visual Examination: VT-3, Line #S2-224-8. Support ID: 75-17R.
Drawing 051399, (75-17R VT3 1028.1038)
Visual Examination: VT-3, Line #K-638-8. Support ID: 42-8R.
Drawing 051361, (42-8R VT3 1028.1039)
Visual Examination: VT-3, Line #K-380-10. Support ID: 414-174A.
Drawing 051414, (414-174A VT3 1028.1031)
Visual Examination: VT-3, Line #K-124-12. Support ID: 24-13R.
Drawing 051360, (24-13R VT3 1028.1039)
Eddy Current Examination: Seal Table Thimble Tube Examination, Conco Job
- 35162, Bottom Mounted Instrumentation Flux Thimble Tubes October 2022
==2R23. October 27, 2022.
Radiography: CR Examination Report: N-RT-1B-CR. Steam Generator==
Blowdown Valve MS-2-1056 Field Weld 1, Work Order 68065800, (FW-1 Reader Sheet.doc 1028.0657)
Radiography: CR Examination Report: N-RT-1B-CR. Steam Generator Blowdown Valve MS-2-1056 Field Weld 2, Work Order 68065800, (FW-2 Reader Sheet.doc 1028.1812)
Radiography: CR Examination Report: N-RT-1B-CR. Steam Generator Blowdown Valve MS-2-1056 Field Weld 3, Work Order 68065800, (FW-3 Reader Sheet.doc 1024.0659)
Welding associated with full replacement of the Steam Generator Blowdown Valve MS-2-1056, Gas Tungsten Arc Welding, Work Order No. 68065800, Field Weld #1. (FW-1_FW-2_FW-3 Technique Sheets.doc 1024.0705)
Welding associated with full replacement of the Steam Generator Blowdown Valve MS-2-1056, Gas Tungsten Arc Welding, Work Order No. 68065800, Field Weld #2. (FW-1_FW-2_FW-3 Technique Sheets.doc 1024.0705)
Welding associated with full replacement of the Steam Generator Blowdown Valve MS-2-1056, Gas Tungsten Arc Welding, Work Order No. 68065800, Field Weld #3. (FW-1_FW-2_FW-3 Technique Sheets.doc 1024.0705)
Welding associated with the Weld Overlay of through wall leak in Line 1140 off of Loop 1 Cold Leg, Code Case N-666-1, Gas Tungsten Arc Welding, (MA3.DC1 Quality Inspection Form DOC 0509.0836)03.01.c - Pressurized-Water Reactor Boric Acid Corrosion Control Activities The inspector reviewed the following documents associated with boric acid leaks and evaluations:
Boric Acid Evaluation Notification: 50843272. Work Order: 60088874, CCP1-3 Inboard Seal Leak w/BA Build Up
Boric Acid Evaluation Notification: 51008030. Work Order: 60134457, Sl-2-8803A: Boric Acid Leak Packing
Boric Acid Evaluation Notification: 51082169. Work Order: 68061001, RCP 2-2 seal has minor leakage
Boric Acid Evaluation Notification: 51087212. Work Order: 60134150, CVCS-0-8783 Boric Acid Leak at Stem
Boric Acid Evaluation Notification: 51094645. Work Order: 60132710, SI PP 1-1 INBD mechanical seal leakage
Boric Acid Evaluation Notification: 51095572. Work Order: 60133523, RCS-1-8033B Boric Acid at Body-Bonnet Boric Acid Evaluation Notification: 51100900. Work Order: 60133426, Through wall BA Leak u/s of CVCS-1 -8305A
Boric Acid Evaluation Notification: 51102884. Work Order: 60146653, U2 SI PP 2-1 Discharge Flange Boric Acid
Boric Acid Evaluation Notification: 51115297. Work Order: 60136527, RHR-2-8702 has wet BA on the packing
Boric Acid Evaluation Notification: 51121630. Work Order: 60137670, CVCS-1-346, Active Water Leak at Packing
Boric Acid Evaluation Notification: 51143064. Work Order: 60142611, CVCS-1-8387B: Wet Boric Acid Leak
Boric Acid Evaluation Notification: 51145107. Work Order: 60143220, SFS-1-8790 BA at body to bonnet.
Problem Identification and Resolution
The inspector reviewed 11 notifications associated with inservice inspection and operating experience issues. No findings or violations of more than minor significance were identified.
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (2 Samples)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during the Unit 2 shutdown for refueling outage 2R23 on October 15, 2022.
- (2) The inspectors observed and evaluated licensed operator performance in the control room during Unit 2 preparation to transition from mode 5 to mode 4 on November 21, 2022.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated a crew of licensed operators during simulator training on December 13, 2022.
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 (SSCs) remain capable of performing their intended function:
(1)oil leak near Unit 1 startup transformer on October 27, 2022
- (2) Unit 2 residual heat removal system shutdown hot leg isolation cooling valve RHR-2-8702 leakage on November 1, 2022 (3)review of periodic 10 CFR 50.65(a)(3) evaluation on December 22, 2022
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 2 Yellow shutdown risk during 2R23 for reduced inventory (reactor water level at 112 feet) with only a single source of offsite power available on October 19, 2022
- (2) Unit 2 transition from mode 5 to mode 4 while the startup transformer was out of service on November 10, 2022
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (4 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 incipient fire detection system on October 3, 2022
- (2) Unit 2 SI-2-8900D not responding during inservice testing on November 7, 2022
- (3) Unit 2 FCV-95 motor brush plate assembly on November 7, 2022
- (4) Unit 2 emergency diesel generator 2-3 commercial grade dedication review on December 21, 2022
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)ammeter modification on October 11, 2022
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:
- (1) Unit 2 auxiliary service water pump 2-1 on October 26, 2022
- (2) Unit 2 safety injection pump 2-1 on October 26, 2022
- (3) Unit 2 auxiliary service water pump 2-2 on November 16, 2022
- (4) Unit 2 RHR-V-8702 valve repack on December 30, 2022
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated Unit 2 refueling outage 2R23 activities from October 15, 2022, to November 23, 2022.
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance testing activities to verify system operability and/or functionality:
Surveillance Tests (other) (IP Section 03.01) (2 Samples)
- (1) Unit 2 exercising safety injection accumulator discharge isolation valves on October 17, 2022
- (2) Unit 2 engineered safety feature bus transfer testing on October 18, 2022
Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)
- (1) Unit 2 penetration 31 containment isolation valve leak testing on November 1,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicator submittals listed below:
BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10)===
- (1) Unit 1 (October 1, 2021, through September 30, 2022)
- (2) Unit 2 (October 1, 2021, through September 30, 2022)
BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)
- (1) Unit 1 (October 1, 2021, through September 30, 2022)
- (2) Unit 2 (October 1, 2021, through September 30, 2022)
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)
- (1) The inspectors reviewed the licensee's corrective action program for potential adverse trends that might be indicative of a more significant safety issue. The inspectors' review was focused on the residual heat removal system during the period from July 1, 2022, to December 31,
INSPECTION RESULTS
Inadequate Testing of the Incipient Fire Detector System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000275,05000323/2022004-01 Open/Closed
[P.2] -
Evaluation 71111.15 The inspectors identified a Green, non-cited violation of Unit 1 License Condition 2.C(5) and Unit 2 License Condition 2.C(4), Fire Protection, for the licensees failure to implement and maintain in effect all provisions of the approved fire protection program. Specifically, the licensees approved fire protection program required the testing of the incipient fire detection system airflow annually. The licensees maintenance testing and procedure for the incipient fire detection system did not conduct annual flow testing to verify adequate airflow through all ports or points to ensure that none of the sample lines were blocked.
Description:
The incipient fire detection system (IFDS) is a very early warning fire detection system (VEWFDS) that samples the air for combustion particles from sample tubes coming out of electrical cabinets. These systems detect fires before ignition occurs and are highly sensitive in comparison to smoke detectors.
In 2017, for Unit 1 and 2018 for Unit 2, the licensee installed four detectors per unit with two in the cable spreading room (7A/7B) and two in the solid-state protection system room (8G/8H) as NFPA 805 modifications. These detectors are incorporated in the NFPA 805 monitoring program and credited in the fire probabilistic risk assessment (PRA) for providing an improvement in the core damage frequency and large early release frequency for both units.
The inspectors reviewed AWP E-046, Detailed Fire Modeling, revision 1, section 11.3.2, that states, in part, that, In addition to regular functional testing required by NFPA 76 and required maintenance by the vendor, the system is tested in accordance with NFPA 72 requirements.
The NFPA 805 safety evaluation (SE), Diablo Canyon Power Plants, Unit Nos. 1 and 2 - Issuance of Amendments Regarding Transition to a Risk-Informed, Performance-Based Fire Protection Program in Accordance with 10 CFR 50.48(c) (CAC Nos. MF2333 and MF2334),dated April 14, 2016 (ML16035A441) references the code of record, and states, in part, in Section 3.1.3.2, Very Early Warning Fire Detection Systems:
That the modification will be installed per the requirements of NFPA 72, National Fire Alarm and Signaling Code, and NFPA 76, Standard for the Fire Protection of Telecommunications Facilities, and will satisfy other FAQ 08-0046 and Code/Standard requirements such as alert and alarm sensitivity, acceptance testing, aspiration, equipment voltage restrictions, and fast-versus-slow fire growth.
NFPA 76-2016, Section 5.6.6, Methods for Verifying Performance, states, The performance predicted by the performance design analysis shall be verified by field testing of the installed systems and subsystems, and Section 6.8.6.3, Installation, Testing, and Maintenance, states, All fire alarm, detection, and alarm notification equipment shall be installed, tested, and maintained in accordance with NFPA 72.
NFPA 72-2016, Chapter 14, Inspection, Testing, and Maintenance, makes a distinction between initial acceptance, visual inspections, and periodic testing. Section 14.3.1 states, in part, that, visual inspections shall be performed in accordance with the schedules in Table 14.3.1, and section 14.4.3.2 states that systems and associated equipment shall be tested according to Table 14.4.3.2.
Excerpt from NFPA 72, Table 14.3.1, Visual Inspections, for Chapter 14, Inspect, Testing, and Maintenance Component Initial Acceptance Periodic Frequency Method Section 17. Initiating Devices Verify location and condition (all devices)
- (a) Air Sampling
- (1) General X
Semiannual Verify that in-line filters, if any, are clean.
17.7.3.6
- (2) Sampling system piping and sampling ports X
N/A Verify that sampling system piping and fittings are installed properly, appear airtight, and are permanently fixed. Confirm that the sampling pipe is conspicuously identified. Verify that sample ports or points are not obstructed.
17.7.3.6 Excerpt from NFPA 72, Table 14.4.3.2, Testing, for Chapter 14, Inspect, Testing, and Maintenance Component Initial Acceptance Periodic Frequency Method
- (4) Air sampling X
Annually Test with smoke or a listed and labeled product acceptable to the manufacturer or in accordance with their published instructions from the end sampling port or point on each pipe run. Verify through all port or points.
As noted in the SE excerpt, section 3.1.3.2, above, the modification will satisfy other FAQ 08-0046 and Code/Standard requirements such as alert and alarm sensitivity, acceptance testing, aspiration, equipment voltage restrictions, and fast-versus-slow fire growth. FAQ 08-0046 (Nov 23, 2009), incorporated into NUREG/CR-6850, supplement 1, in September 2010, includes the following in the discussion of how VEWFDS is supposed to be incorporated into the risk model, specifically in the description of the event tree assumptions for Detection Systems Availability and Reliability:
In addition to the regular functional testing required by NFPA 76 and any required preventive maintenance required by the vendor, the system should be tested and maintained in accordance with NFPA 72 and all vendor requirements (Calibrated as required by the manufacturer).
The inspectors engaged the Office of Nuclear Reactor Regulation (NRR) fire protection technical staff for additional insight and considered the licensees position that Section 3.1.3.2 in the NFPA Safety Evaluation, refers only to the installation of the VEWFDS and that this section is in response to the licensees NFPA 805 License Amendment Request (DCL-13-065 supplemented by DCL-15-119), section 4.8.2.1, which only addressed design and installation of the system, not ongoing maintenance and testing requirements. The staff disagreed and concluded that DCPP is required to annually verify airflow through the system.
The inspectors reviewed the testing recommendations provided by the vendor. The vendor guidance stated, in part, that all periodic checks may be performed except for Annual Checks which must be performed every 12 months and required checking the transport times at the furthest sampling point on each pipe. The inspectors clarified with the licensee and NRR that a transport time test is not the same as an airflow balance test from all ports.
The inspectors also noted that the vendor guidance states, in part, that, these instructions do not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with the installation, operation, or maintenance of cirrus pro systems.
The inspectors confirmed that from installation of the IFDS in 2017 to 2021, the sample lines were not opened and tested annually. In October 2021, a full flow airflow balance test was performed on each sample port for both units due to airflow falling outside of the desired range. It was noted that when the licensee performed the airflow balance, there were instances where as-found airflow required balancing adjustments. In August 2022, the licensee performed another functional test on the IFDS and identified issues that the site had to assess for functionality. The inspectors noted that for both tests, the licensee still considered them enhancements even though there were degraded conditions that required an assessment and resolution to address compliance.
Corrective Actions: The licensee has established additional preventive maintenance tasks for testing above and beyond vendor recommendations by performing annual flow balancing and will ensure that an appropriate amount of flow is available at each sample port.
Corrective Action References: Notification 51136652 was created on November 11, 2021, to implement a recurring maintenance plan to verify the flow balance for each IFD and sample each manifold on a 12-month frequency to assure an individual sample point being restricted or blocked does not go unnoticed. SAPN 51175083 was created on December 15, 2022, to address the lack of flow balance testing from 2018-2021 according to NFPA 72 and the requirement to perform annual flow testing.
Performance Assessment:
Performance Deficiency: The failure to annually test the incipient fire detection systems was a performance deficiency. Specifically, the licensees approved fire protection program requires the testing of the incipient fire detection system airflow annually, but the licensees maintenance testing and procedure for the IFDS does not require annual flow testing to verify adequate airflow through all ports or points to ensure that none of the sample lines are blocked.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the protection against external factors 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 loss of the incipient fire detection system greatly reduces the licensees ability to promptly detect and respond to a significant plant fire in a timely manner. When the licensee started performing the air flow balancing on the IFDS, there were multiple instances where the as-found airflow required adjustments and instances of potential blockage of airflow in the system, which reduced available response time for detecting fire in the cabinets and areas/zones.
Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP, using Attachment 1, Fire Protection Significance Determination Process Worksheet which requires classifying the degradation as high or low. Per step 1.2, the inspector assigned the finding category as Fixed Fire Protection Systems and the element covered by finding category as Fixed fire detection systems before proceeding to Step 1.3 - Low Degradation Deficiencies.
2 provides degradation rating guidance and criteria used to answer 1.3.1-A Question that states, is this finding assigned a low degradation rating? Low degradation findings based on the degrading rating reasoning in attachment 1, screen to Green, or very low safety significance. This finding screened to Green and required no further analysis.
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, in 2021, as a corrective action, the licensee performed full flow balancing on each detector sample port for both units due to instances where flow fell outside of the desired range. The licensee had an opportunity to proceduralize the testing requirements and address testing concerns but considered it an enhancement rather than a requirement based on vendor guidance. The inspectors determined that the licensee relied too heavily on the vendor without fully understanding the testing requirements for the IFDS.
Enforcement:
Violation: Diablo Canyon Unit 1 License Condition 2.C(5) and Unit 2.C(4), Fire Protection, require the licensee to implement and maintain all provisions of the approved fire protection program. The approved fire protection program includes incipient fire detection systems meeting the requirements of the National Fire Protection Association standard NFPA 72, National Fire Alarm and Signaling Code, 2016 Edition, which requires annual air sampling testing for air sampling components in table 14.4.3.2. Table 14.4.3.2 requires, in part, that the testing methodology test from the end sampling port of point on each pipe run and verify airflow through all other ports or points.
Contrary to above, since May 21, 2017, the licensees maintenance and testing procedure for the IFDS did not require annual flow testing to verify adequate airflow from the end sampling port of point on each pipe run and verify airflow through all other ports or points.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with section 2.3.2 of the Enforcement Policy.
Unresolved Item (Open)
Residual Heat Removal Suction Isolation Valve Leakage URI 05000323/2022004-02 71111.19
Description:
The inspectors identified an unresolved item related to the licensee's deferral of a post-maintenance test on valve RHR-2-8702, Unit 2 reactor coolant system (RCS) Loop 4 hot leg to residual heat removal (RHR) pump suction header valve.
In April 2021, a wet boric acid valve packing leak was identified at the follower for valve RHR-2-8702. The boric acid leak was cleaned and the packing retorqued, reducing, but not stopping the leakage. In November 2022, valve RHR-2-8702 was cycled prior to plant restart and the leakage through its lower packing set increased. This resulted in unacceptable leakage to the pressurizer relief tank through the valve packing leak-off line. Slight leakage out of the upper packing set was also present. Detailed inspection of the stem for valve RHR-2-8702 identified damage in the form of linear galling, including areas of raised metal, on the portion of the stem that passes through the valve packing. The licensee believed that this galling damaged the valve packing, thereby causing the observed packing leakage. A repack of the valve while in mode 5 was performed for the purpose of eliminating leakage to the pressurizer relief tank as well as the external leakage.
Because the maintenance involved a motor operated valve (MOV), station Procedure AD13.ID4, Post Maintenance Testing, revision 34, Attachment 3, MOV Post-Maintenance Testing Requirements, provides the standard post-maintenance testing activities. The required testing following valve re-packing maintenance would include: an exercise stroke time test, an inservice leak test, an MOV static diagnostic test, and a seat leakage test. The station completed the seat leakage test and the inservice leak check prior to returning Unit 2 to power operations, to demonstrate the leakage safety function of valve RHR-2-8702 was maintained. Valve RHR-2-8702 isolates the low-pressure RHR system from the high-pressure RCS to prevent an intersystem loss of coolant accident (LOCA). As such, this valve is maintained in the closed position with power removed from the valve's motor operator during modes 1, 2, and 3 per technical specification 3.5.2. Furthermore, valve RHR-2-8702 is an RCS pressure isolation valve per technical specification 3.4.14, which requires that this valve be leak tested each refueling outage. Thus, the successful performance of the seat leakage test and the inservice leak check demonstrated that the closed safety function of valve RHR-2-8702 was maintained. However, the licensee chose to defer the portion of the post-maintenance test that would demonstrate other functions important to safety. The licensee chose to defer stroke time testing and MOV static diagnostic testing because of the concern that exercising the valve could cause further damage to the packing material by the damaged stem, leading to leakage during the subsequent cycle.
Valve RHR-2-8702 is included on the List of Active Valves in FSAR, table 3.9-9. This table specifies in NOTE 23, Valve does not have an active safety function to support accident mitigation or Mode 3 safe shutdown. Valve is active to support achieving post-Hosgri cold shutdown. Valve needs to be seismically qualified for active function for Hosgri only. Post-Hosgri refers to a licensing commitment related to a seismic event originating at the Hosgri fault line. Thus, the licensee concluded that opening valve RHR-2-8702 is a licensing basis function required to achieve cold shutdown, only after a Hosgri earthquake.
Calculation DCM S-10, section 4.3.3.3, states that the ability to achieve cold shutdown (mode 5) with no concurrent accident following a Hosgri earthquake is a licensing commitment. This function would be demonstrated via an exercise stroke time test and an MOV static diagnostic test. The station completed an evaluation to support deferment of the exercise stroke time test and the MOV static diagnostic test until 2R24 scheduled for May 2024.
The current Diablo Canyon Inservice Testing (IST) Program Plan dated March 2, 2016, implementing ASME OM Code (2004 Edition), subsection ISTA, paragraphs ISTC-3200(a)and ISTC-3110, specifies that valve RHR-2-8702 is an Active Category A valve with applicable ASME OM Code requirements, including exercise stroke time testing, position indication verification testing, and seat leakage testing. On November 24, 2022, the station provided the inspectors with an evaluation stating that valve RHR-2-8702 would be reclassified as a Passive Category A valve for the purposes of testing under the Diablo Canyon Power Plant IST program. In the evaluation, the licensee states that the specified exercise stroke time testing is beyond the requirements of the ASME OM Code, and that it was only included as a good engineering practice. As stated in the System Power Operated Valve Basis Document for the Diablo Canyon Power Plant IST program, The stroke time test is maintained in the IST PP because the valves are opened anyway each refueling for Shutdown Cooling operation. The licensee concluded that valve RHR-2-8702 meets the requirements to be scoped into the program as a Passive Category A valve because it is not required to change obturator position to accomplish its required pressure isolation function.
The station's November 24, 2022, evaluation states that the ability of valve RHR-2-8702 to perform its post-Hosgri opening function is supported by the actuator selected for this application: the Limitorque SMB-1 actuator and 40 ft-lb motor, which the station believes has adequate margin to accommodate increases in running loads which may occur with variations in packing friction. The licensees evaluation did not include the specific assumptions used in its calculation of the operating capability of valve RHR-2-8702 to overcome the galling of the valve stem. The specific cause of the galling of the valve stem and whether it might increase during valve operation are unknown.
A Pacific Gas and Electric (PGE) letter dated January 26, 1978 (ML17093A389), states that PGE and the NRC staff discussed the detailed description of the plant procedures to respond to a postulated Hosgri earthquake for Diablo Canyon. The PGE letter states that the minutes of a meeting on November 22, 1977, include agreements between the PGE and the NRC staff for system and equipment used in the shutdown procedure. The specific agreements between the NRC staff and PGE in the minutes of the meeting on November 22, 1977, to provide assurance that plant components will be able to respond to a postulated Hosgri event (including the operating capability of valve RHR-2-8702) have not been determined at this time. For example, FSAR, section 5.5.6.4.17, specifies that RHR system MOVs 8701 and 8702 are subject to the requirements of Generic Letter 89-10, June 1989, and associated Generic Letter 96-05, September 1996, and meet the requirements of the DCPP MOV Program Plan.
In response to inspector questions, the licensee noted that deferral of post-maintenance testing (PMT) is allowed for valve stem packing adjustments based on NUREG-1482. The licensee stated that a similar approach was used to demonstrate that PMT involving valve cycling may be deferred for replacement of packing material. The licensees evaluation quoted a portion of section 4.4.2 of NUREG-1482 related to packing adjustments and backseating. However, the guidance in section 4.4.2 of NUREG-1482 is not applicable to complete replacement of valve stem packing. For example, section 4.4.2 of NUREG-1482 states that the IST requirements do not prohibit or discourage a licensee from making limited adjustments to valve packing to stop a leak that may be adversely affecting the valve or surrounding components.
This issue is unresolved because the inspectors have not yet been able to determine whether there is a violation associated with the testing deferral and will need to review the licensees IST program change package and consult with the Office of Nuclear Reactor Regulation.
Planned Closure Actions: The licensee plans to update the IST program plan and basis document to change the classification of this valve (and other similar valves in both units) to a Passive Category A valve.
The NRC plans to review the licensees updates to determine whether the changes meet Title 10 of the Code of Federal Regulations (10 CFR) 50.55a, ASME OM Code requirements, and post-Hosgri event commitments. The NRC also plans to review the basis for removal of these valves from the Generic Letter 89-10 and 95-05 programs, and the licensees basis for their conclusion that the valve stem repair and repacking did not adversely affect the valves ability to open.
Licensee Actions: The licensee successfully stroked closed valve RHR-2-8702 following stem repair and repacking. The NRC did not identify any immediate safety concerns that the valve would not be capable of being opened (either remotely or manually) following a post-Hosgri event should the plant be required to be placed in a cold shutdown condition.
Corrective Action References: Notifications 51172859, 51115297, 51115552, 51115682, and
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On November 17, 2022, the inspectors presented the Inservice inspection results to Adam Peck, Site Vice President, and other members of the licensee staff.
On December 15, 2022, the inspectors presented the incipient fire detection inspection results to Paula A. Gerfen, Senior Vice President, Generation and Chief Nuclear Officer, and other members of the licensee staff.
On January 5, 2023, the inspectors presented the integrated inspection results to Paula A. Gerfen, Senior Vice President, Generation and Chief Nuclear Officer, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
Notifications
50955469, 51154663, 51166186, 51176148
Drawings
106712-2
Containment Spray System
OP A-2:X
Place RVRLIS In Service
OP AP-15
Loss of Feedwater Flow
OP AP-2
Full Load Rejection
20A
OP AP-25
Rapid Load Reduction or Shutdown
OP C-7A:I-A
Condensate and Booster Pumps - Alignment Checklist
OP I-2:I
Containment Spray System - Make Available
OP I-2:II
Containment Spray System - Alignment Verification Checklist
for Plant Startup
OP J-6B:III
Diesel Generator 2-3 - Make Available
40A
OP J-6B:III-A
Diesel Generator 2-3 - Alignment Checklist
OP K-10
Systems Requiring Sealed Component Checklists
OP K-10K
Sealed Valve Checklist for Emergency Diesel Generators
11A
OP O-35
Bumped Component Protection Program
Procedures
OP1.DC20
Sealed Components
Work Orders
Corrective Action
Documents
Notifications
51166337
111805-63
Fire Preplan Unit 2 Turbine Building, Elevation 104-foot
111805-64
Fire Preplan Unit 2 Turbine Building, Elevation 104-foot
111805-65
Fire Preplan Unit 2 Turbine Building, Elevation 119-foot
111805-66
Fire Preplan Unit 2 Turbine Building, Elevation 119-foot
Drawings
11805-43
Fire Preplan Unit 2 Containment Building Elev. 140'
Work Orders
89-13
Cable Spreading Room AC System - Hydronic and Air Flow
Calculations
2/11/2005
Calculations
89-17
Cable Spreading Room A/C System - Determination of Max
Flood Depth After a MELB of the Chilled Water Lines at El.
115'-0"
05/19/1989
Corrective Action
Notifications
51174824, 51174857
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Documents
Resulting from
Inspection
Krautkramer,
Model USN60SW,
Serial Number
2PPL
Ultrasonic Instrument Calibration Data Record and
Certification.
06/27/2022
SGS Lab Number
V5031132
SGS Certificate of Analysis. Spotcheck SKD-S2 Aerosol,
Developer Dye Penetrant, Batch/Lot: 18L03K
2/06/2019
SGS Lab Number
V5031161
SGS Certificate of Analysis - Spotcheck SKC-S Aerosol,
Cleaner Remover. Batch/Lot: 18C20K
2/07/2019
SGS Lab Number
V5032785
SGS Certificate of Analysis, Couplant Soundsafe INDL
Ultrasound; Batch/Lot: 19F033
10/10/2019
SGS Lab Number
V5033003
SGS Certificate of Analysis. Spotcheck SKL-SP2 Aerosol,
Penetrant Dye, Batch/Lot: 19E02K.
11/07/2019
SGS Lab Number
V5035344
SGS Certificate of Analysis. Spotcheck SKC-S Aerosol,
Batch/Lot: 20H01K
10/07/2020
Calibration
Records
SGS Lab Number
V5036148.
SGS Certificate of Analysis. Penetrant Dye Spotcheck SKL-
SP2 Aerosol, Batch/Lot: 20M10K
01/22/2021
Corrective Action
Documents
Notifications
51057867, 51112196, 51113323, 51119147, 51128830,
51129715, 51144818, 51148702, 51149041, 51151550,
51152257, 51154978, 51161606, 60148506
Corrective Action
Documents
Resulting from
Inspection
Notifications
51167237, 51169287
Agencywide
Documents
Access and
Management
System Accession
No. ML 17139C628
Diablo Canyon Power Plant, Units 1 and 2 - Request for Relief
to the ASME Code,Section XI, Examination Requirements for
Class 1 and Class 2 Piping Welds for the Fourth 10-Year
Inservice Inspection Interval (CAC NOS. MF9706 AND
MF9707; EPID L-2017-LLR-0030)
2/15/2018
Miscellaneous
Customer PO #:
Weldstar Certificate of Compliance. Customer PO #:
08/06/2009
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
3500845084, Ship
Ticket #: N848611
3500845084, Ship Ticket #: N848611. Weld Wire
PQR No. 201
Procedure Qualification Record 201 for Base Metal Specs
SA-182 Type 316 to Itself.
09/30/1983
PQR No. 235
Procedure Qualification Record 235, GTWA and SAW for
Material Specification SA-240-304 to SA-240-304
04/15/1985
PQR No. 499
Procedure Qualification Record 499 for GTAW for Base Metal
Specs A240 to 304L Plate.
05/02/1990
AD4.ID2
Plant Leakage Evaluation
ER1.ID2
Boric Acid Corrosion Control Program
RHR Hot Leg 1 and 2, 8703 to 8740 A and B, Pressurization
for ISI Inspection
0A
ISI X 2
Visual Inspection of Reactor Upper Internals and Fuel
Assembly Guide Pins
ISI X 3
Core Plate and Core Support Structure Examination for
Foreign Objects
Reactor Vessel Top and Bottom Head Visual Inspections
ISI X-101
Reactor Coolant System Pressure Boundary Pressure Test
(Portions of ASME Class 1 and 2 Requiring Operator
Assistance
ISI X-CRDM
Reactor Vessel Top and Bottom Head Visual Inspections.
MA3
Special Processes
Magnetic Particle Examination Procedure
Ultrasonic Examination of Austenitic Piping
Visible Dye Liquid Penetrant Examination Procedure
Ultrasonic Examination of Pressure Vessel Welds Other than
Reactor Vessels
NOZ
Ultrasonic Examination of Accumulator Tank Nozzles and
Similar Fittings
Ultrasonic Detection and Sizing of Vessel Nozzle Inside
Radius
Ultrasonic Instrument Linearity Verification
Visual Examination of Component Surfaces
Procedures
Visual Examination During Section XI System Pressure Test
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Visual Examination During Section XI System Pressure Test
Visual Examination of Component and Piping Supports
Visual Examination of Component Interiors
General Visual Examination of the Containment Liner
PDI-UT-2
PDI Generic Procedure for the Ultrasonic Examination of
Austenitic Pipe Welds
PDI-UT-2
PDI Generic Procedure for the Ultrasonic Examination of
Austenitic Pipe Welds
STP R-8C
Containment Walkdown for Evidence of Boric Acid Leakage
Notification
50601807
Quick HIT Self-Assessment for Reactor Coolant System
Materials Degradation Management Program (RCS MDMP)
and Steam Generator Management Program (SGMP)
2/19/2013
Self-Assessments
Notification
51067384
DCPP Inservice Inspection Program 2020 Formal Self-
Assessment
08/17/2020
Corrective Action
Documents
Notifications
297191, 50406133, 50568449, 50607511, 50616671,
50661719, 50662776, 50664721, 50664723, 50671890,
50710197, 50850787, 50853883, 51070582, 51106078,
51115297, 51115552, 51115682, 51146570, 51164610,
51167940, 51168553, 51169000, 51169488, 51170673,
51170998, 51171048, 51171594, 51172273, 51172697,
51172771, 51174817
Drawings
663219-430
Piping 14 Motor Operated Gate Valve Assembly
Licensee White Paper on RHR-2-8702
11/24/2022
Hosgri Seismic Report
1978
221122131955
Diablo Canyon Power Plant Inservice Testing Program Bases
DCM S-10
Diablo Canyon Power Plant, Units 1 and 2, Design Criteria
Memorandum: Residual Heat Removal System
Miscellaneous
Licensees letter: Use of RHR-2-8702 following a Hosgri
seismic event.
01/26/1978
MA1.ID17
Maintenance Rule Monitoring Program
MA1.NE1
MR Monitoring Program - Civil Implementation
Procedures
OM15.ID4
Self-assessment and Benchmarking, Quick Hit
Work Orders
60136527
RHR-2-8702 Repack Valve
11/19/2022
Corrective Action
Notifications
51170432
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Documents
Miscellaneous
2R23 Outage Safety Plan
Procedures
AD8.DC55
Outage Safety Checklist - Attachment 6: Mode 5 Loops Filled
Corrective Action
Documents
Notifications
51088141, 51115230, 51128221, 51169715, 51169995,
51170374, 51175057
Miscellaneous
RPE M-6602
Sixth Diesel Engine and Mechanical Parts
Procedures
TP TB-22001
Functional Test of ECCS Check Valve SI-1-8900D
Corrective Action
Documents
Notifications
50600264
DCN2000001677
25VDC Vital Battery & Charger Unfused Non-Class 1E
Ammeter
DCN2000001678
25VDC Vital Battery & Charger Unfused Non-Class 1E
Ammeter Circuits
DCN2000001679
25VDC Vital Battery & Charger Unfused Non-Class 1E
Ammeter Circuits
Miscellaneous
DCP1000025266
Install fuses on the Non-Class 1E ammeter circuits associated
with the U1 vital batteries and battery chargers. A new fuse
box for mounting of the fuses will be installed in the vicinity of
each SD panel inside each of the vital 125VDC Switchgear
Rooms located in the 115 Elevation of the Auxiliary Building
Work Orders
WO 68049141, 68049142, 68049166, 68049166-0030, 68049167,
68049167-0030, 68049167-0050, 68049167-0070, 68049168,
68049168-0030, 68049169, 68049169-0030, 68049170,
68049170-0030, 68049170-0050, 68049170-0060
Corrective Action
Documents
Notifications
50927265, 50937861, 51006811, 51086109, 51086319,
51088988, 51091116, 51110366, 51113920, 51115297,
51115552, 51115682, 51134680, 51136652, 51137032,
51139290, 51167940, 51168553, 51169488, 51170998,
51171048, 51172697, 51172771, 51174817
Diablo Canyon Power Plant, Unit Nos. 1 and 2 - Issuance of
Amendments Regarding Transition to a Risk-Informed,
Performance-Based Fire Protection Program in Accordance
with 10 CFR 50.48(c)(CAC NOS. MF2333 and MF2334)
04/14/2016
Miscellaneous
663089-245-1-2
Cirrus Pro Aspirating Fire Detector
05/09/2017
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
663089-247-1-2
Site Acceptance Test, PROX4 VEWFDS
05/21/2017
DCM No. S-17B
Design Criteria Memorandum DCM S-17B Auxiliary Saltwater
System
DCM No. S-9
Design Criteria Memorandum S-9 Safety Injection System
AWP E-046
Detailed Fire Modeling
MP I-18-IFD
Incipient Fire Detection System Maintenance
STP 1-18-IFD.A
U2
Incipient Fire Detection System Operability and Channel
Functional Test
STP 1-18-IFD.A
U3
Incipient Fire Detection System Operability and Channel
Functional Test
STP M-26
ASW System Flow Monitoring - ASWP 2-1
Procedures
STP P-SIP-A21
Comprehensive Test of Safety Injection Pump 21
Work Orders
WO 60133219, 60133219 1-EFID01, 60133219 1-EFID02,
60133219 1-EFID03, 60133219 1-EFID04, 60135842,
60135842 2-EFID01, 60135842 2-EFID02, 60135842 2-
EFID03, 60135842 2-EFID04, 60148437
OP AP-20
Condenser Tube Leak
OP L-5
Plant Cooldown from Minimum Load to Cold Shutdown
110
Procedures
OP L-8
Separating from the Grid while Maintaining Reactor Power
Less Than 30%
AD2.ID1
Procedure and Work Plan Use and Adherence
STP M-13F
4KV Bus F Non-SI Auto-Transfer Test
STP M-13G
4KV Bus G Non-SI Auto-Transfer Test
61A
STP M-13H
4KV Bus H Non-SI Auto-Transfer Test
53A
STP V-2P1
Exercising Accumulator Isolation Valve
STP V-3L4
Exercising Valves SI-8808A, B, C, and D Accumulator
Discharge Isolation Valves
Procedures
STP V-631
Penetration 31 Containment Isolation Valve Leak Testing
Work Orders
WO 64135011, 64135819, 64207727, 64252541, 64255374,
255375, 64255376, 64255377
Corrective Action
Documents
Notifications
50359140, 50572355, 51141806, 51154083
71151
Miscellaneous
Shift Logs-Various
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
WCAP 16465 NP
Pressurized Water Reactor Owners Group Standard RCS
Leakage Action Levels and Response Guidelines for
Pressurized Water Reactors
CAP D-6
Specific Activity Determination in Liquid Samples
STP I -1B, Unit 1
Routine Daily Checks Required by Licenses
131
STP I -1B, Unit 2
Routine Daily Checks Required by Licenses
110
STP R-10C,
Unit 1
Reactor Coolant System Water Inventory Balance
Procedures
STP R-10C,
Unit 2
Reactor Coolant System Water Inventory Balance
Corrective Action
Documents
Notifications
51151095, 51157330, 51159057, 51162003, 51166042,
51166365, 51167133, 51167134, 51167940, 51168483,
51168553, 51169488, 51170673, 51170927, 51171046,
51171048, 51171078, 51171518, 51171897, 51172273,
51172697, 51172771, 51174817, 51175455
OM4.ID14
Notification Review Team (NRT)
35A
Procedures
OM7.ID1
Problem Identification and Resolution
58