IR 05000282/2021001
| ML21126A224 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/06/2021 |
| From: | Hironori Peterson Region 3 Branch 3 |
| To: | Domingos C Northern States Power Company, Minnesota |
| References | |
| IR 2021001 | |
| Download: ML21126A224 (13) | |
Text
May 6, 2021
SUBJECT:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT - INTEGRATED INSPECTION REPORT 05000282/2021001 AND 05000306/2021001
Dear Mr. Domingos:
On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Prairie Island Nuclear Generating Plant. On April 12, 2021, 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.
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,
/RA/
Hironori Peterson, Chief Branch 3 Division of Reactor Projects
Docket Nos. 05000282 and 05000306 License Nos. DPR-42 and DPR-60
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000282 and 05000306
License Numbers:
Report Numbers:
05000282/2021001 and 05000306/2021001
Enterprise Identifier: I-2021-001-0048
Licensee:
Northern States Power Company
Facility:
Prairie Island Nuclear Generating Plant
Location:
Welch, Minnesota
Inspection Dates:
January 01, 2021 to March 31, 2021
Inspectors:
K. Pusateri, Resident Inspector
D. Tesar, Senior Resident Inspector
Approved By:
Hironori Peterson, Chief
Branch 3
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Prairie Island Nuclear Generating Plant, 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
Type Issue Number Title Report Section Status LER 05000282/2020-001-00 LER 2020-001-00 for Prairie Island Nuclear Generating Plant (PINGP) Unit 1,
Reactor Trip Caused by Spurious Neutron Flux Signal During Reactor Protection System Testing 71153 Closed LER 05000282,05000306/
2021-001-00 LER 2021-001-00 for Prairie Island Nuclear Generating Plant (PINGP), Unit 1, 12 Diesel Driven Cooling Water Pump Auto Start Due to Low System Pressure 71153 Closed
PLANT STATUS
Units 1 and 2 operated at or near full power for the entirety of the inspection period, except for brief power reductions to perform surveillance testing or flexible power operations.
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 plant status activities described in IMC 2515, Appendix D, Plant Status, and conducted routine reviews using IP 71152, Problem Identification and Resolution. 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 2019 (COVID-19), resident inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time, the resident inspectors performed periodic site visits each week; conducted plant status activities as described in IMC 2515, Appendix D, Plant Status; observed risk-significant activities; and completed on-site portions of IPs. In addition, resident and regional baseline inspections were evaluated to determine if all or portions of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on-site. The inspections documented below met the objectives and requirements for completion of the IP.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)
- (1) Walkdowns of extreme cold winter weather preparations on 02/03/2021
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) U2 B Train cooling water header during A Train maintenance on 01/22/2020
- (2) U2 caustic addition piping walkdown on 02/02/2021
- (3) U1 electrical lineup walkdown during 1R transformer work window on 02/09/2021
- (4) U1 and U2 AFW walkdown and partial alignment on 03/01/2021
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) U2 safeguards DC power on 03/22/2021
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
- (1) Fire zone 97-1, location (El.718'), D5 4KV Bus 25 Room/D5 knob room on 01/12/2020
- (2) Fire zone 43, Bus 111 fire walkdown on 02/03/2021
- (3) FC-37 Bus 150/160 room on 01/26/2021
- (4) Fire zone 97-11, (El. 735'), D5 480V Bus 211/212 room on 02/24/2021
- (5) Fire zone 31 and 32 (El. 695') on 03/01/2021
Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)
- (1) Unit 2 (El. 735') area fire under U2 main generator on 01/19/2020
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
- (1) Unit 2 safeguards Bus 25 source switching control room observation on 03/01/2021
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated simulator training scenario observation on 03/08/2021
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (1 Sample)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
(1)11 cooling water strainer leak on 03/11/2021
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (6 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) Walkdown of protected equipment on 02/02/2021
- (2) Walkdown during 22 DDCLP work on 01/26/2021
- (3) T-3 scope freeze and risk review on 02/18/2021
- (4) PRA risk assessment for Bus 15/16 crosstie on 02/22/2021
- (5) Risk walkdown during 122 safeguards control room chiller work on 02/24/2021
- (6) T-3 scope freeze and risk review on 03/13/2021
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
(1)11 cooling water strainer leak on 02/23/2021
- (2) Containment spray MV surveillance on 03/08/2021 (3)12 safeguards sample isolation CIV on 03/09/2021 (4)122 safeguards control room chiller on 03/02/2021 (5)23 CFCU past operability review on 02/09/2021
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (6 Samples)
The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:
(1)11 turbine driven auxiliary feed water pump on 01/12/2021
- (2) Post maintenance testing of 22 diesel driven cooling water pump on 01/28/2021 (3)122 safeguards room chiller annual maintenance post maintenance testing on 02/24/2021
- (4) D5 diesel outage post maintenance on 03/15/2021 (5)12 diesel driven cooling water pump monthly test on 03/04/2021
- (6) D2 diesel outage post maintenance testing on 03/22/2021
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
(1)11 containment spray pump quarterly test on 01/08/2020 (2)11 turbine driven auxiliary feed water pump on 01/12/2020
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) SP 1118 Verifying Paths from the Grid to U1 Buses on 02/09/2021
Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)
(1)
===31404 12 SG Power Operated Isolation Valve on 03/09/2021
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01)
=
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
Unplanned Scrams per 7000 critical hours on 03/15/2021
IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 03.01)===
- (1) Unit 1 Unplanned Scrams per 7000 (January 1, 2020 through December 31, 2020) on 03/15/2021
- (2) Unit 2 Unplanned Scrams per 7000 (January 1, 2020 through December 31, 2020) on 03/15/2020
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02) (2 Samples)
- (1) Unit 1 Unplanned Power Changes per 7000 Critical Hours (January 1, 2020 through December 31, 2020) on 03/15/2021
- (2) Unit 2 Unplanned Power Changes per 7000 Critical Hours (January 1, 2020 through December 31, 2020) on 03/15/2021
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 03.03) (2 Samples)
- (1) Unit 1 Unplanned Scrams with Complications (January 1, 2020 through December 31, 2020) on 03/15/2021
- (2) Unit 2 Unplanned Scrams with Complications (January 1, 2020 through December 31, 2020) on 03/15/2021
71153 - Follow-up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors evaluated the following licensee event reports (LERs):
- (1) LER 2020-001-00 for Prairie Island Nuclear Generating Plant (PINGP) Unit 1, Reactor Trip Caused by Spurious Neutron Flux Signal During Reactor Protection System Testing (ADAMS Accession No. ML20293A439). The inspectors determined that it was not reasonable to foresee or correct the cause discussed in the LER therefore no performance deficiency was identified. The inspectors did not identify a violation of NRC requirements.
- (2) LER 2021-001-00 for Prairie Island Nuclear Generating Plant (PINGP), Unit 1, 12 Diesel Driven Cooling Water Pump Auto Start Due to Low System Pressure (ADAMS Accession No. ML21081A290). The inspection conclusions associated with this LER are documented in this report under Inspection Results Section
INSPECTION RESULTS
Minor Performance Deficiency 71153 Minor Performance Deficiency: On 01/26/2021, the Prairie Island Nuclear Generating Station was performing planned maintenance on the Safety Related (S-R) 22 Diesel Driven Cooling Water Pump. Additionally, as part of a separate planned maintenance item, they isolated the 22 Cooling Water (CL) strainer. Although the station assessed the quantitative risk as required by 10 CFR 50.65(a)(4), the station failed to assess the qualitative risk and system response associated with these two concurrent planned maintenance items as required by their procedural requirements in FP-WM-IRM-01, Integrated Risk Management, resulting in an unplanned auto initiation of the S-R standby 12 DDCLP. This presented a challenge to Operations personnel to recover the system and return the 12 DDCLP to a standby lineup and was a reportable event IAW 10 CFR 50.73 Licensee Event Report.
The licensee placed this issue into their Corrective Action Program as QIM 501000048107.
An Apparent Cause Evaluation (ACE) was performed which concluded that Operations and the Work Week Managers did not identify the system impact from the concurrent activities of taking a CL strainer out-of-service during the 22 DDCLP work window. This failure to assess the qualitative risk and system response was a Performance Deficiency (PD).
The inspectors reviewed the Licensee Event Report (LER) and ACE and did not find issue with the apparent and direct causes identified or the corrective actions to address those causes. Several corrective actions were implemented, including revised procedures and work instructions for future maintenance on the CL system during times of low flow.
Screening: The inspectors determined the performance deficiency was minor. Ultimately there was no change in Online Risk, nor any unavailability or Tech Spec inoperability, therefore this issue was determined to be of very low safety significance and screened to minor. The inspectors did not identify a violation of regulatory requirements.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On April 12, 2021, the inspectors presented the integrated inspection results to Mr. Domingos, Site Vice President, and other members of the licensee staff.
THIRD PARTY REVIEWS
Inspectors reviewed Institute on Nuclear Power Operations reports that were issued during the inspection period.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
AB-2
Abnormal Procedure - Severe Weather
TP 1637
Periodic Test Procedure - Winter Plant Operation
Work Orders
Annual Winter Plan Operation
10/28/2020
Procedures
Fire Detection
Zone 97
F5 Appendix A
71111.11Q Procedures
2C20.5
Control Room Observation-Unit 2-4.18Kv System
Procedures
Quality Control Inspection Log
03/22/2021
Calibration
Records
ENG-EE-021
(Current)
Diesel Generator Steady State Loading for an SI Event
Concurrent with Loss of Offsite Power (LOOP) for 01, 02,
05, 06
Corrective Action
Documents
501000044766
Breaker 16-9 B Phase Lower Stab Crack
09/27/2020
501000049155
CS Pump Discharge MV Lessons Learned
03/02/2021
501000049987
D6 Emergency Diesel Generator, Unit 2, B-Train
03/30/2021
Drawings
NF-40002-2
Single Line Metering and Relaying 4.16kV Switchgear Bus
and 16 D1 and D2 Emergency Generators
NF-40022-1
Circuit Diagram 4kV and 480V Safeguard Buses
11/04/1991
Engineering
Evaluations
EC
608000000596
Bus 16-9 Stab Operation with Cracked Flange
ENG-EE-170
ETAP Bus Data - Attachment 2A
EV
608000000596
EC Evaluation - Bus 16-9 Stab Operation with Cracked
09/27/2020
EV
608000000614
Evaluate Contact Resistance for Bus 16
09/28/2020
Miscellaneous
LER 1-01-05
Fault and Fire in Non-Safeguards Circuit Breaker Results in
Reactor Trip and Auxiliary Feedwater System Actuation
10/02/2001
Procedures
1C20.5
Unit 1 - 4.16kV System
NF-40002-3
Single Line-Metering and Relaying Safeguard and Normal
4.1kV Switchgear Feeder Unit 1 and 2
10/11/1994
PE 0009
4kV Switchgear Preventative Maintenance
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Orders
WO 00095518 01
Bus 16 Inspection/Doable
05/05/2006
WO 00359703 01
Bus 16 Inspection/Doable
07/16/2012
0010
PF-2 Bus16 Inspection/ Doble
09/24/2020
Miscellaneous
D5 EDG MD-
2422
Procedures
D5 EDG MD-
2422
D5 EDG MD-32422
Work Orders
PE 3002-3-12 DDCLP Electric Inspection
11/17/2020
Corrective Action
Documents
501000049048
MV-32105 Diagnostic Test Results
2/25/2021
Miscellaneous
MV-32105
MOV Diagnostic Test Trending Summary - Prairie Island
Nuclear Generating Plant UNIT 1
03/25/2021
Procedures
501000048725
GAMP: Actual Void Value at 1RH-09
2/27/2021
501000048725
GAMP: Actual Void Volume at 1RH-09
2/17/2021
SP 1090A
Containment Spray Pump Quarterly Test
SP 1102
Turbine Driven Aux Feed Water Pump
SP 1118
Verifying Paths from the Grid to U-1 Buses
SP 1468.01
Unit 1 GL-08-01 Inspections for Modes 1, 3 and 4
Work Orders
NSPM Nuclear MOV Program (MV-32105)
Prairie Island Nuclear Generating Plant Unit 1
2/25/2021
Calibration
Records
501000048107
DDCLP Auto Start
2/23/2021
Corrective Action
Documents
501000043602
Root Cause Evaluation Report - Unit 1 Flux Rate RX Trip
501000048107
DDCLP Auto Start
Miscellaneous
Unit 1 Licensee
Event Report
(LER) 2021-001 -
50-282/2021-
Diesel Driven Cooling Water Pump Auto Start Due to Low
System Pressure 5.
03/22/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
001-00