IR 05000275/2021010
| ML21068A347 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 03/11/2021 |
| From: | Nick Taylor NRC/RGN-IV/DRS/EB-2 |
| To: | Welsch J Pacific Gas & Electric Co |
| Scott L | |
| References | |
| IR 2021010 | |
| Download: ML21068A347 (15) | |
Text
March 11, 2021
SUBJECT:
DIABLO CANYON POWER PLANT, UNITS 1 AND 2 - TRIENNIAL FIRE
PROTECTION INSPECTION REPORT 05000275/2021010 AND
Dear Mr. Welsch:
On February 11, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Diablo Canyon Power Plant, Units 1 and 2. On February 11, 2021, the NRC inspectors discussed the results of this inspection with Ms. P. Gerfen, Site Vice President 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. 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, Nicholas H. Taylor, Chief Engineering Branch 2 Division of Reactor Safety
Docket Nos. 05000275 and 05000323 License Nos. DPR-80 and DPR-82
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000275 and 05000323
License Numbers:
Report Numbers:
05000275/2021010 and 05000323/2021010
Enterprise Identifier: I-2021-010-0009
Licensee:
Pacific Gas and Electric Company
Facility:
Diablo Canyon Power Plant, Units 1 and 2
Location:
Avila Beach, CA
Inspection Dates:
January 25, 2021 to February 11, 2021
Inspectors:
J. Mateychick, Senior Reactor Inspector
N. Okonkwo, Reactor Inspector
G. Pick, Senior Reactor Inspector
Approved By:
Nicholas H. Taylor, Chief
Engineering Branch 2
Division of Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a triennial fire protection 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 Carbon Dioxide Fire Suppression System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000275;05000323/2021010-01 Open/Closed None (NPP)71111.21N.
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 adequately test the carbon dioxide suppression system. The licensee's approved Fire Protection Program requires testing of the carbon dioxide fire protection system every 18 months. The licensee's testing sequence for pilot valves in the system did not duplicate the system operation during an actuation should a demand occur.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards. Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the Coronavirus Disease (COVID-19), regional inspectors were directed to begin teleworking. During this time regional baseline inspections were evaluated to determine if all or portions of the objectives and requirements stated in the IP could be performed remotely. In some cases, portions of an IP were completed remotely and on-site. The inspection documented below was determined that the objectives and requirements stated in the IP could be completed remotely.
REACTOR SAFETY
===71111.21N.05 - Fire Protection Team Inspection (FPTI)
Structures, Systems, and Components (SSCs) Credited for Fire Prevention, Detection, Suppression, or Post-Fire Safe Shutdown Review (IP Section 03.01)===
The inspectors verified that components and/or systems will function as required to support the credited functions stated for each sample. Additional inspection considerations are in the fire risk evaluation report (FRE) or nuclear safety capability assessment (NSCA).
- (1) The auxiliary feedwater system and 125 Volt DC power supply system supporting post-fire safe shutdown.
- (2) The fire water system including the fire water tank, fire pumps, and yard loop distribution piping system.
- (3) Carbon dioxide fire suppression system protecting the cable spreading rooms (Fire Areas 7-A and 7-B) in both units.
- (4) Incipient Fire Detection Systems and Smoke Detection Systems installed in the cable spread room (Fire Areas 7-A and 7-B) for both units.
Fire Protection Program Administrative Controls (IP Section 03.02) (2 Samples)
The inspectors verified that the selected control or process is implemented in accordance with the licensees current licensing basis. If applicable, ensure that the licensees fire protection program contains adequate procedures to implement the selected administrative control. Verify that the selected administrative control meets the requirements of all committed industry standards.
- (1) The inspectors reviewed the licensees administrative controls of hot work, transient combustibles, and fire impairments.
- (2) The inspectors reviewed the licensees fire brigade training program.
Fire Protection Program Changes/Modifications (IP Section 03.03) (2 Samples)
The inspectors evaluated the licensee's procedures controlling modifications and procedure revisions for adequacy in reviewing potential impacts to the fire protection program.
- (1) The inspectors reviewed Fire Protection Change Evaluations associated with NFPA 805, Chapter 3, "Fundamental Fire Protection Program and Design Elements."
- (2) The inspectors reviewed Fire Protection Change Evaluations associated with the Nuclear Safety Capability Assessment and the Recovery Action Feasibility Assessment.
INSPECTION RESULTS
Inadequate Testing of the Carbon Dioxide Fire Suppression System Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000275;05000323/2021010-01 Open/Closed None (NPP)71111.21N.0 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 adequately test the carbon dioxide suppression system. The licensee's approved Fire Protection Program requires testing of the carbon dioxide fire protection system every 18 months. The licensee's testing sequence for pilot valves in the system did not duplicate the system operation during an actuation should a demand occur.
Description:
The inspectors selected the carbon dioxide fire suppression systems for the cable spreading rooms (Fire Areas 7-A and 7-B) as an inspection sample. The licensee's approved fire protection program requires testing every 18 months in accordance with surveillance test procedure STP M-39B, Routine Test of Cable Spreading Room CO2 Fire System Operation. This testing satisfies Equipment Control Guideline 18.5, CO2 System, surveillance requirements 18.5.1.3 and 18.5.1.4.
The testing confirms proper system actuation by the six thermal detectors in the room and the two pushbuttons. System actuation requires two valves to open to discharge carbon dioxide into the room. One valve is located in piping above the carbon dioxide tank in the Unit 1 turbine building isolating the piping to both cable spreading rooms and all six diesel generator rooms. The second valve is near the room and opens to allow discharge of carbon dioxide into the individual room.
These valves are normally held closed by an internal spring. During a system actuation, the systems own carbon dioxide is used to pressurize the space above an internal piston to open the valve against the spring's force. Pressurizing and venting that area of the valve is controlled by an external pilot valve. Normally the internal shuttle of the pilot valve is in the vent (closed) position.
During a system actuation, a solenoid valve is energized to provide carbon dioxide to a connection on the pilot valve in order to move the internal shuttle into the pressurizing position. The pilot and solenoid valves are in the wall mounted boxes with an open/close handle behind a break glass window. The handle shaft has a cam which depresses the pilot valve shaft moving the valve shuttle to the pressurizing position.
The inspectors noted that the licensees surveillance testing procedure included performance of the following steps involving the valve before the first test actuation energizing the solenoid valve. The licensee inspects the pilot valve, the glass cover is removed from the pilot valve box, and the pilot valve is manually opened and closed using the handle. The procedure directs repeating this as necessary to ensure smooth valve operation. The system test proceeds when the pilot valve has been sufficiently exercised to ensure smooth valve operation.
This sequence of testing the pilot valve does not confirm it would have operated properly during a system actuation since it is exercised prior to as-found testing. The system control panel opens the solenoid valve supplying carbon dioxide to the pilot valve in order to reposition the pilot valve internal shuttle. The testing method does not demonstrate the pilot valve would have operated successfully in the manner required during a system actuation since the pilot valve has already been manually exercised.
The licensee's surveillance test procedures apply this inspection method and testing sequence to all 15 pilot valves in the carbon dioxide fire suppression system. The carbon dioxide fire suppression systems are tested every 18 months. The inspectors determined that since this testing methodology was adopted in 2010 there have been no reports of difficulty operating any pilot valve due to internal binding. In addition, the inspectors noted that one system actuation has occurred during this time frame and that the two pilot valves in the system operated properly.
Corrective Actions: The licensee is evaluating changes to the system testing sequence.
Corrective Action References: The licensee entered the issue to the corrective action program as Notification 51105394.
Performance Assessment:
Performance Deficiency: The failure to adequately test the carbon dioxide suppression system was a performance deficiency. Specifically, the testing sequence for pilot valves in the system does not duplicate the system operation during an actuation should a demand occur.
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.
Significance: The inspectors assessed the significance of the finding using NRC Inspection Manual Chapter 0609, Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP.
1, Fire Protection Significance Determination Process Worksheet requires classifying the degradation has high or low. Attachment 2 provides degradation rating guidance. For gaseous based suppression, lack of test data is classified as low degradation. In Attachment 1, low degradation findings screen to Green, or very low safety significance.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. The licensee established the current testing sequence in 2010 as part of the corrective actions following an uncontrolled discharge of carbon dioxide into the Unit 1 main turbine lube oil room during testing.
Enforcement:
Violation: Unit 1 License Condition 2.C.(5) and Unit 2 License Condition 2.C.(4), "Fire Protection," require the licensee to implement and maintain all provisions of the approved fire protection program. The approved fire protection includes a carbon dioxide suppression system meeting the requirements of the National Fire Protection Association standard NFPA 12, Carbon Dioxide Extinguishing Systems, 1968 Edition. NFPA 12, Section 17, Inspection, Maintenance and Instruction, includes subsection 1711, which states, "The goal of this inspection and testing shall be not only to insure that the system is in full operating condition but shall indicate the probable continuance of that condition until the next inspection."
Contrary to the above, from 2010 to February 11, 2021, the licensees testing failed to adequately unsure that the system is in full operating condition and indicate the probably continuance of that condition until the next inspection. Specifically, the licensee's testing sequence failed to demonstrate that the system pilot valves would operate as designed in their normal standby condition using pressure provided by the carbon dioxide if required by a system actuation.
Enforcement Action: This violation is being treated as a non-cited violation, 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 February 11, 2021, the inspectors presented the triennial fire protection inspection results to Ms. P. Gerfen, Site Vice President and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.21N.05 Calculations
1000024930
Unit 1 Hot Shutdown Panel Upgrade
9000041466
Nuclear Safety Capability Assessment (NSCA)
9000041468
Recovery Action Feasibility Assessment (RAFA)
9000041689-003-
NFPA 805 Design Basis Document U1&2
2/15/2020
9000041845
NFPA 805 Combustible Control Levels
10/21/2019
Calculation F.3.5
Development of Fire-Induced Risk Model
Calculation G.2
Diablo Canyon Power Plant Human Reliability Analysis -
All Hazards
Corrective Action
Documents
A0620761 50323903 50366336 50541606 50630969
50929434 50960091 50960235 50970852 50973595
50979273 50983723 50984012 50985455 50996494
50998176 50999272 51000923 51006811 51022441
51023903 51023932 51024114 51026411 51027305
51028325 51030772 51031120 51031121 51039193
51053364 51053480 51063316 51063563 51074218
51081238 51085423 51099926 51100215 51103639
51103857 51103871 51103921 51104084 51104087
51104433 51033736
Corrective Action
Documents
Resulting from
Inspection
51105394
Drawings
2001, Sheet 3
Drawing Symbols
2018, Sheet 2
Fire Protection Systems - Yard Loop
106
2018, Sheet 3
Fire Protection Systems - Firewater Pumps
2018, Sheet 6
Carbon Dioxide Fire Protection System Hazard Spray
Heads
2018, Sheet
6A
Carbon Dioxide Fire Protection System Hose Reels
106703, Sheet 3
Auxiliary Feedwater System
106704, Sheet 2
High Pressure Turbine West Side Main Steam Supply
110
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
106704, Sheet 3
High Pressure Turbine East Side Main Steam Supply
115
106704, Sheet 4
Auxiliary Feedwater Pump 1 1
118
106707, Sheet 3
Pressurizer Spray Valves
106708, Sheet 2
Letdown System - Reactor Coolant Pump Seal Supply
and Return Details
2
106708, Sheet 3
Letdown System - Flow Orifice Valves and Charging
Return Valve
131
106708, Sheet 5
Letdown System - Volume Control Tank Outlet and
Charging Pump Discharge Valves
151
106709, Sheet 3
Safety Injection System - Supply Valves from Refueling
Water Storage Tank
106709, Sheet 4
Safety Injection System - Supply Valves from Refueling
Water Storage Tank to Residual Heat Removal Suction
106714, Sheet 2
Component Cooling Water - Supply Valves
106714, Sheet 6
Component Cooling Water - Supply to Reactor Coolant
Pump Thermal Barrier Heat Exchanger
106725, Sheet 25 Instrument Air to Atmospheric Relief Valves
211
106725, Sheet 26 Instrument Air to Atmospheric Relief Valves
216
106725, Sheet 38 Instrument Air to Atmospheric Relief Valves
211
106725, Sheet 43 Instrument Air to Atmospheric Relief Valves
164
111906, Sheet 1
Fire Protection Cover Sheet
111906, Sheet 2
Fire Protection Symbols
111906, Sheet 25 Fire Protection Auxiliary Building Elevations 128', 154',
164' and 174'
Engineering
Evaluations
2017-009
Changes to Nuclear Safety Capability Assessment,
Revision 2
2018-008
Changes to Nuclear Safety Capability Assessment,
Revision 4
2018-009
Changes to Recovery Action Feasibility Assessment
(RAFA), Revision 4
2019-001
Changes to Nuclear Safety Capability Assessment,
Revision 5
2019-002
Changes to Recovery Action Feasibility Assessment
(RAFA), Revision 5
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Fire Protection
Engineering
Evaluation 029
Fire Traps for the Diesel Generator Rooms
& 1
Fire Protection
Engineering
Evaluation 166
Barrier Separating Turbine Building at Elevation 140 Feet
and Auxiliary Building
U1 Cardox Discharge Root Cause Analysis Report
Miscellaneous
NFPA Transition Report
June 2013
Fire Protection Program Health Report 2019-Q4 Through
20-Q3
1-TS-19-0271
minutes and Continuous Fire Watch Status Log
3/22/19
DCM No. S-18
Fire Protection System
ECG 18.1
Fire Suppression Systems/Fire Suppression Water
Systems
2/12/20
ECG 18.3
Fire Detection Instrumentation
ECG 18.5
CO2 System
2/04/17
EPM-DP-RSD-
001
Fire Risk Evaluations
Lesson R205C1
Continuing Training for AP 8 Series Procedures
01/04/2021
N/A
2018 1st Quarter Fire Drill Lessons Learned
2018
N/A
Fire Protection Impairments (FPI) List
N/A
N/A
2-14-18 Drill Documentation Record
2/14/18
N/A
2018 4th Quarter Fire Drill Lessons Learned
2018
N/A
CAP for 2018 Fourth Quarter FD Lessons Learned
20
N/A
2019 4th Quarter Fire Drill Lessons Learned
2019
0030
Establishing Recovery Actions
Nuclear Power Plant Fire Ignition Frequency and Non-
Suppression Probability Estimation Using the Updated
Fire Events Database
01/2015
Refining and Characterizing Heat Release Rates from
Electrical Enclosures During Fire
06/2016
Methodology for Modeling Fire Growth and Suppression
Response for Electrical Cabinet Fires in Nuclear Power
06/2020
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Plants
Procedure
Commitment
T36905
CO2 System Testing Requirements
R2044-001-6A1
Detailed Fire Modeling Report, Fire Compartment: 6 A 1,
Unit 1 Battery, Inverter and DC Switchgear, F Bus
R2165-007-001
NFPA 805 Risk Informed Performance Based Fire Risk
Evaluations
R2851-006-001
Address Diablo Canyon Power Plant Notifications
STP M-69B
CO2 Hose Reels, Valves, and Bottles, and Deluge Valve
Inspections
2/21/2020
STP M-69B
CO2 Hose Reels, Valves, and Bottles, and Deluge Valve
Inspections
1/19/2021
TCP-14410
Transient Combustible Permit # 14410
2/28/2020
Updated Final
Safety Analysis
Report Section
9.5.1
Fire Protection
Vendor Manual
No. 663086-170
CARDOX Fire Extinguishing Equipment
Procedures
AD13.DC6
Fire Protection System Performance Based Surveillance
Program
5A
AR PK10-10
Fire Detected
AWP E-007
Fire Protection Engineering Evaluations
AWP E-007
Fire Protection Engineering Evaluations
AWP E-046
Detailed Fire Modeling
CP M-6
Site Fire Response
ECG 18.1
Fire Water Systems/Fire Suppression Water Systems
ECG 18.2
Fire Hose Stations
ECG 18.3
Fire Detection Instrumentation
ECG 18.4
Spray and/or Sprinkler Systems
ECG 18.5
CO2 System
ECG 18.7
Fire Rated Assemblies
MP I-18-IFD
Incipient Fire Detection System Maintenance
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
OM4.ID3
Operating Experience Program
OM8
OM8.ID2
Fire System Impairment
OM8.ID4
Control of Flammable and Combustible Materials
OM8.ID5
Fire Protection Program Administration
OM8.ID6
Fire Protection Change Evaluation
0A
OM8.ID6
Fire Protection Change Evaluation
OA
OM8.ID8
Equipment Important to NFPA 805 Fire Response
OP AP-34
Fire Response Initial Actions
OP AP-34.3.20
Fire Response - Solid State Protection System Room
OP AP-34.5.2
Fire Response - Cable Spreading Room
OP AP-8
Control Room Inaccessibility - Establishing Hot Standby
OP1.ID2
Time Critical/Sensitive Operator Actions
P1890-002-004
Fire Protection Code Conformance Review
Fire Pump 0-2 Routine surveillance
STP I-18-IFD.A
Incipient Fire Detection System OPERABILITY and
CHANNEL FUNCTIONAL Test
STP I-34A
Fire Detector System Detector Functional Panel A
STP M-39A1
Routine Test of Diesel Generator 1-1 or 2-1 Room CO2
Fire System Operation
STP M-39B
Routine Test of Cable Spreading Room CO2 Fire System
Operation
STP M-39C
Routine Test of Turbine Lube Oil Room CO2 Fire System
Operation
STP M-39D
Routine Surveillance Test of Carbon Dioxide Hose Reels
18A
STP M-39E
Routine Test of Turbine Generator Bearing Number 10
CO2 Fire System Operation
21A
STP M-63A
Fire Water System Flow Alarm Test
33A
STP M-63E
Fire Water System Yard Loop Flush
STP M-69B
CO2 Hose Reels, Valves, and Bottles, and Deluge Valve
Inspections
STP M-70A
Inspection of Fire Barrier and HELB Seals
STP M-70B
Inspection of Fire Dampers
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
STP M-70D
Inspection of Rated Fire Assemblies, Except Penetration
Seals, Dampers and Doors
STP M-71
Firewater System Flow Test
& 13
STP P-FPP-A01
Fire Pump 0-1 Performance Test
& 8
STP P-FPP-A02
Fire Pump 0-2 Performance Test
& 9
STP P-FPP-B01
Fire Pump 0-1 Routine Surveillance
STP P-FPP-B02
Fire Pump 0-2 Routine Surveillance
TQ1.DC12
Fire Brigade and Emergency Response Training
Work Orders
64178182 60118264 64228584 69119941 60119941
203241 60116772 64178190 64203252 64233868
230186 64230187 64233871 64230188 64233872
230189 64233873 64231654 64235481 64231655
235482 64231656 64235483 64231657 64235484
221447 64213425 64216996 64225497 64180000
208048 64004772 60117800 64004778 60083142
60111417 60119941 60129503 60125902