IR 05000277/2022011
| ML22138A376 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 05/18/2022 |
| From: | Mel Gray NRC/RGN-I/DORS |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Gray M | |
| References | |
| IR 2022-011 | |
| Download: ML22138A376 (11) | |
Text
May 18, 2022
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - DESIGN BASIS ASSURANCE INSPECTION (PROGRAMS) INSPECTION REPORT 05000277/2022011 AND 05000278/2022011
Dear Mr. Rhoades:
On April 8, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Peach Bottom Atomic Power Station, Units 2 and 3 and discussed the results of this inspection with Mr. David Henry, Site Vice President and other members of your staff. The results of this inspection are documented in the enclosed report.
No findings or violations of more than minor significance were identified during this inspection.
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, Mel Gray, Chief Engineering Branch 1 Division of Operating Reactor Safety
Docket Nos. 05000277 and 05000278 License Nos. DPR-44 and DPR-56
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000277 and 05000278
License Numbers:
Report Numbers:
05000277/2022011 and 05000278/2022011
Enterprise Identifier: I-2022-011-0021
Licensee:
Constellation Energy Generation, LLC
Facility:
Peach Bottom Atomic Power Station, Units 2 and 3
Location:
Delta, PA
Inspection Dates:
March 21, 2022 to April 8, 2022
Inspectors:
E. Dipaolo, Senior Reactor Inspector
D. Kern, Senior Reactor Inspector
N. Mentzer, Reactor Inspector
Approved By:
Mel Gray, Chief
Engineering Branch 1
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a design basis assurance inspection (programs) inspection at Peach Bottom Atomic Power Station, Units 2 and 3, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
No findings or violations of more than minor significance were identified.
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.
REACTOR SAFETY
71111.21N.02 - Design-Basis Capability of Power-Operated Valves Under 10 CFR 50.55a Requirements POV Review (IP Section 03)
The inspectors:
a. Determined whether the sampled power-operated valves (POVs) are being tested and maintained in accordance with NRC regulations along with the licensees commitments and/or licensing bases.
b. Determined whether the sampled POVs are capable of performing their design-basis functions.
c. Determined whether testing of the sampled POVs is adequate to demonstrate the capability of the POVs to perform their safety functions under design-basis conditions.
d. Evaluated maintenance activities including a walkdown of the sampled POVs (if accessible).
- (1) MO-0-33-0498, Emergency Service Water (ESW) Return to Discharge Pond
- (2) MO-3-02-053B, Recirculation Pump Discharge Isolation Valve
- (3) MO-3-10-013A, Residual Heat Removal Pump 3AP035 Torus Suction Isolation Valve
- (4) MO-3-10-025A, Residual Heat Removal Loop A, Inboard Discharge Valve
- (5) MO-3-13-021, Reactor Core Isolation Cooling Pump Discharge to B Feedwater Line
- (6) MO-3-14-005D, D Core Spray Pump Minimum Flow Valve
- (7) MO-3-23-014, High Pressure Coolant Injection Turbine Steam Supply Valve
- (8) AO-0-33-0241B, ESW Outlet Block Valve from E2 Diesel Generator Coolers
- (9) AO-2-01A-080D, Inboard D Main Steam Isolation Valve
- (10) AO-2-03-35B, Scram Discharge Volume Outboard Isolation Vent Valve
- (11) AO-2-07B-2511, Torus 18 Vent Inboard Isolation Valve to SBGT/ATMOS
- (12) AO-3-01A-080A, Inboard A Main Steam Isolation Valve
INSPECTION RESULTS
Very Low Safety Significance Issue Resolution Process: Emergency Heat Sink (including ESW-0498, ESW Return to Pond) Safety Classification and Inservice Test (IST) Requirements 71111.21 N.02 This issue is a current licensing basis question and inspection effort is being discontinued in accordance with the Very Low Safety Significance Issue Resolution (VLSSIR) process. No further evaluation is required.
Description:
The Peach Bottom 5th 10-Year Test Interval Inservice Test (IST) Program Plan, Revision 16 identified that valve MO-0-33-0498, ESW Return to Pond, had a passive safety function to remain open. This open safety function supported cooling for the emergency diesel generators and the emergency core cooling system rooms during normal plant operation. The Plan specified that the associated IST requirement was a biennial position indication verification (PI) test.
The inspectors determined MO-0-33-0498 also had an active safety function to close, which was not documented in the 10-Year IST Program Plan. The Peach Bottom Updated Final Safety Analysis Report (UFSAR) credited this active function to provide closed-loop emergency heat sink (EHS) operation to support safe shutdown of Units 2 and 3 in the event of a loss of normal heat sink (Conowingo Pond) or a design basis flood. The inspectors further determined the EHS system, including MO-0-33-0498 was safety-related. The basis for this conclusion included the following:
- (1) 10 CFR 50.2 defines safety-related components as those relied upon to remain functional during and following design basis events (DBE) to assure. the capability to maintain the reactor in a safe shutdown condition, or the capability to prevent or mitigate the consequences of accidents leading to offsite exposures comparable to 10 CFR Part 100 exposure guidelines.
- (2) Peach Bottom UFSAR Section 2.4.3.5 identified EHS as a safe shutdown system, required to mitigate two design basis events; the design flood condition (Run-up of the Maximum Wave Superimposed on the Probable Maximum Flood Water Level) and a loss of normal heat sink (e.g., seismic DBE damages the Conowingo dam).
- (3) UFSAR Section 10.9.3 credited EHS to mitigate both the design flood condition and a loss of normal heat sink (loss of Conowingo pond).
- (4) Section ISTA-1100(a) of the ASME OM 2012 Code defines IST scope to include pumps and valves required to shut down a reactor, maintain safe shutdown, or mitigate consequences of an accident.
- (5) The inspectors determined that if the EHS was unavailable, a design basis seismic event which caused a loss of normal heat sink event and loss of offsite power could lead to offsite exposures comparable to 10 CFR Part 100 exposure guidelines.
Notwithstanding these conclusions, the inspectors noted the design did not provide for redundancy in the MO-0-33-0498 closure function as would be typical for a safety-related system. The inspectors further noted the closed-loop EHS function was added late in the original licensing of Peach Bottom Units 2 and 3 as a result of additional oversight reviews.
Section III-3600 of the ASME OM 2012 Code required active motor operated valves (MOVs)to be exercised (e.g., stroked open and closed) at least once per refueling cycle. Section ISTA-3110 of the ASME OM 2012 Code required the 10-year IST Program Plan to include the code requirements for each component and the test(s) to be performed. The inspectors reviewed station operating procedures and identified 19 EHS components (pumps and valves), including MO-0-33-0498, which were operated or verified by operators when placing EHS in closed-loop operation. Accordingly, the inspectors determined all 19 components were required to be tested in accordance with the ASME OM Code.
The inspectors verified that, with the exception of the MO-0-33-0498 active closure function, the ASME OM Code IST test requirements for the EHC system were properly identified in the 10-year IST Plan. Even EHS pumps and valves with no safety function identified in the Plan, had appropriate tests specified as though the components were credited for active safety functions. The inspectors also determined that MO-0-33-0498 was exercised and PI verified in accordance with annual surveillance test ST-O-033-310-2 (last performed 1/14/22).
Although Constellation staff considered the MO-0-33-0498 active closure function to be non-safety-related and outside of the ASME OM Code scope, they have been performing the testing required by the ASME OM Code for an active MOV. The inspectors reviewed maintenance and test records for the last 5 years and found no problems identified for MO-0-33-0498.
Licensing Basis: Constellation staff classified MO-0-33-0498 as safety-related and therefore within the scope of ASME OM Code IST requirements, for its passive safety function to remain open to return ESW cooling water from the emergency diesel generators and emergency core cooling system loads to the Conowingo Pond (e.g., river). The active function of MO-0-33-0498 to close isolates the return flow path to the Conowingo Pond and supports closed-loop operation of the EHS in the case of the Loss of Conowingo Pond Special Event. Constellation engineers acknowledged that the loss of Conowingo Pond was part of Peach Bottoms design and licensing basis. However, Constellation staff determined the EHS and the MO-0-33-0498 active closure function were augmented quality (non-safety-related), because they were not credited to mitigate any analyzed design basis accident or transient described in Chapter 14 of the UFSAR. Therefore, Constellation staff concluded EHS and the MO-0-33-0498 active closure function did not fall within the scoping criteria specified in ASME OM Code, ISTA-1100 because they were non-safety-related.
Constellation staff also stated that two previous NRC-approved licensing actions (Peach Bottom conversion to Improved Standard Technical Specifications (ISTS) and Peach Bottom IST Program Third 10-year Interval Update) accepted the licensee determination that EHS and the MO-0-33-0498 active closure function were augmented quality (non-safety-related). The NRC safety evaluation report (SER) for the ISTS conversion (dated 8/30/95)documented the licensee statement that the emergency cooling water pump (part of EHS)was not credited for mitigation of design bases accidents or transients, and accepted the licensees proposed alternative testing. The NRC SER for the IST Program Update (dated 5/11/98) stated the licensee should evaluate the applicability of MO-0-33-0498 and EHS components to the IST program. The licensee responded (dated 1/29/99) that the classification of EHS and the MO-0-33-0498 closure function was augmented quality (non-safety-related) because the components did not support mitigation of any design basis transient or accident. The NRC response (dated 3/15/00) to this letter repeated the licensee position that the components were augmented quality and found the alternative testing proposed by the licensee to be acceptable.
The inspectors noted the purpose of the two licensing actions was for the licensee to request NRC approval for alternative test requirements, in lieu of the existing IST Code and Peach Bottom technical specification test requirements. The associated NRC SERs stated that the specified components were subject to the testing requirements of the IST program and approved the proposed alternative test requirements. However, after stating the components were subject to requirements of the IST program, the SER documented the licensee position that the components were not credited with mitigation of design basis accidents and were augmented quality. These statements appear to conflict. The inspectors concluded the SERs and associated documentation did not make a clear determination of whether MO-0-33-0498 and the EHS were safety-related quality or were non-safety-related quality.
Significance: For the purpose of the VLSSIR process, the inspectors screened the issue of concern through IMC 0612, Issue Screening, and determined the issue of concern would likely be of minor significance had a performance deficiency been identified. Additionally, the issue of concern was similar to IMC 0612, Appendix E, Examples of Minor Issues, example 3.b, because the documentation error in the 10-year IST Plan did not result in any missed IST tests or adversely impact MO-0-33-0498 reliability.
The inspectors also verified the following information which provides reasonable assurance that EHS and MO-0-33-0498 will continue to meet the regulatory requirements of 10 CFR 50.55a(B)(3)(ii):
- (2) Regulatory commitments by Constellation and procedures are in place regarding this periodic IST testing;
- (3) Constellation staff informed the inspectors that there are no current plans to revise this testing; and
- (4) The inspectors noted that changes to the associated IST test procedures would require review through the 10 CFR 50.59 safety evaluation process.
Technical Assistance Request: No Technical Assistance Request was processed in support of this issue.
Corrective Action Reference: Constellation entered the issue into the corrective action program as Issue Report
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On April 8, 2022, the inspectors presented the design basis assurance inspection (programs) inspection results to Mr. David Henry, Site Vice President and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.21N.02 Corrective Action
Documents
01335599
01420676
01537143
04013582
04378793
Corrective Action
Documents
Resulting from
Inspection
04486879
04486979
04486991
04487131
04487138
04487271
04490276
04490281
04490910
04491096
04491472
04492216
04494831
Drawings
280-M-315, Sht.
Emergency Service Water and High Pressure Service
Water
Revision 92
280-M-315, Sht.
Emergency Service Water and High Pressure Service
Water
Revision 95
280-M-330
Sht.1
Emergency Cooling System
Revision 39
Engineering
Changes
EC 07-00344
Differing Detail of Tech Spec Basis & PIMS CRL Safety
Function
Revision 0
MO-3-23-014 Actuator Upgrade SMB1 to SB1
Revision 0
Approve MPR Anti-Rotation Device for Recirculation
Valves
Revision 0
Evaluate BWROG Document TP16-1-112, Revision 5 for
Applicability to Peach Bottom Recirculation Valves
Revision 0
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Engineering
Evaluations
Evaluation
Report MO-3-02-
053B
AC Motor Operated GL 96-05 Gate Valve
Revision 11
PMC-21-128124
Peach Bottom, System 14 Core Spray MOV/IST Alternate
Treatment Plan
2/23/2021
Miscellaneous
BWR Main Steam Isolation Valve (MSIV) PM Template
Revision 2
280-M-1-JJ-80
MSIV Vendor Technical Manual
Revision 1
910328 NRC
GNL 88-14
Peach Bottom Response to NCR P-91152
03/28/1991
A-391-VC-8
Vendor Technical Manual
Revision 1
Commitment
Change
Evaluation
290603,
Assignment 02-
2/24/2020
DBD P-S-09
Residual Heat Removal System
Revision 19
Vendor Technical Manual
Revision 0
NRC Information Notice 2013-14
Potential Design Deficiency in Motor-Operated Valve
Control Circuitry
08/23/2013
P-S-19
Recirculation System
Revision 19
P-S-25B
Primary Containment Auxiliary Systems
Revision 10
PB-5069-14-14A-
003
CFR 50.69 System Categorization Document - Core
Spray System
Revision 1
Scram Discharge Vent and Drain Valve Functional Test
01/08/2022
PCIS Valves Colder Shutdown Inservice Test
11/05/2021
"A" RHR Loop Pump, Valve, Flow and Unit Cooler
Functional and Inservice Comprehensive Test
03/01/2021
HPCI Pump, Valve, Flow and Unit Cooler Functional and
In-service Test without Vibration Data Collected
2/28/2022
Recirculation Pump Discharge Valve Operability Test
11/01/2021
IST Exercise of ESW Air Operated Valves
2/26/2022
Main Steam Isolation Valve Closure Timing
11/03/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
Preventive Maintenance Program
Revision 5
PCM Templates
Revision 1
CFR 50.69 Alternative Treatment Implementation
Process
Revision 5
Diagnostic Testing of Motor Operated Valves
Revision 14
Periodic Inspection of Limitorque Model SMB/SB/SBD
SBD-000 through 5 Motor Operated Valves
Revision 15
Scaffold Installation, Inspection, and Removal
Revision 12
MA-MA-796-024-
1001
Scaffolding Criteria for the Mid Atlantic Stations
Revision 9
Control of Transient Combustible Material
Revision 26
SO 48.1.B
Emergency Cooling Water System Startup
Revision 20
HPSW Pump, Valve and Flow Functional and Inservice
Test
Revision 42
Work Orders
246550
247914
250943
252128
264168
04306865
04869070
04880360
05133013
R1155387
R1196156