IR 05000263/2020003
| ML20315A114 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 11/09/2020 |
| From: | Hironori Peterson Division Reactor Projects III |
| To: | Conboy T Northern States Power Company, Minnesota |
| References | |
| IR 2020003 | |
| Download: ML20315A114 (12) | |
Text
November 9, 2020
SUBJECT:
MONTICELLO NUCLEAR GENERATING PLANT - INTEGRATED INSPECTION REPORT 05000263/2020003
Dear Mr. Conboy:
On September 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Monticello Nuclear Generating Plant. On October 6, 2020, 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 No. 05000263 License No. DPR-22
Enclosure:
As stated
Inspection Report
Docket Number:
05000263
License Number:
Report Number:
Enterprise Identifier: I-2020-003-0030
Licensee:
Northern States Power Company, Minnesota
Facility:
Monticello Nuclear Generating Plant
Location:
Monticello, MN
Inspection Dates:
July 01, 2020 to September 30, 2020
Inspectors:
R. Elliott, Acting Sr. Resident Inspector
J. Harvey, Acting Sr. Resident Inspector
M. Holmberg, Senior Reactor Inspector
D. Krause, Resident Inspector
J. Weigandt, 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 Monticello 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
None.
PLANT STATUS
The unit began the inspection period at full power and operated at approximately full power, except for the following: flexible power operations over the quarter for electric grid efficiencies, and for several reductions in power to approximately 80 percent to meet river discharge temperatures then returning to 100 percent power.
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 (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 and during that time conducted plant status activities as described in IMC 2515, Appendix D; 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 a portion 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) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of extreme hot weather, to include the impact of high river and ambient temperatures on service water cooled systems
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (2 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) High pressure coolant injection on September 10, 2020 (2)
'A' core spray post maintenance on September 17, 2020
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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 (FZ) FZ-07-C, 125 volts Division 2 battery on September 10, 2020
- (2) FZ-12-A, lower 4 kilovolts (kV) room on September 10, 2020
- (3) FZ-14-A, upper 4 kV room on September 10, 2020
- (4) FZ-23-B, intake structure corridor on September 5, 2020
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) Fire pump P-110, discharge piping integrity in the intake structure after maintenance
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during the diesel fire pump test on September 5, 2020
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated MT Simulator licensed operator requalification exam on August 11, 2020
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) Group 1 isolation logic on July 28, 2020
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
- (1) Low pressure coolant injection (LPCI) and main steam line Hi flow relay planned maintenance - Yellow fire risk on July 24, 2020
- (2) Group 1 differential pressure instrument switch (DPIS) planned maintenance on July 27, 2020
- (3) Work week risk from August 31, 2020, to September 4, 2020
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (2 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (2) Safety/Relief Valve (SRV) tailpipe differential pressure transmitter (DPT) primary containment penetration test missed on September 8, 2020
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)
The inspectors evaluated the following temporary or permanent modifications:
- (1) Remove reactor feed pump start interlock POS-2375 and POS-2376
- (2) ATWS modification, replacement of Rosemount 510 trip units
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the following post maintenance test activities to verify system operability and functionality:
(1)11 emergency service water (ESW) pump on July 15, 2020
- (2) Main steam line differential pressure indicating switch on July 22, 2020
- (3) K-1F, 16 INST, and service air compressor, PMT on July 28, 2020 (4)97-54, 12 emergency diesel generator low voltage degraded voltage relay on July 28, 2020
- (5) B3315, D-10, 125VDC charger for 11 battery 480 VAC on August 3, 2020
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
(1)0006 SCRAM discharge volume HI level SCRAM on July 7, 2020
- (2) Drywell high pressure scram, and group 2 & 3 isolation test and Cal on July 20, 2020
- (3) B3315, D-10, 125 VDC charger for 11 battery 480 VAC on August 3, 2020 (4)1070 Reactor core isolation coolant (RCIC) flow control dynamic test on August 11, 2020
- (5) Safety bus under voltage test on August 13, 2020
- (6) Standby gas treatment 'B' test on August 16, 2020
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) Standby liquid control pump and valve test on August 5,
OTHER ACTIVITIES - BASELINE
71152 - Problem Identification and Resolution
Semiannual Trend Review (IP Section 02.02) (1 Sample)
The inspectors reviewed the licensees corrective action program related to the following issue(s):
- (1) Potential adverse trends in degrading work management practices.
Annual Follow-up of Selected Issues (IP Section 02.03) (1 Sample)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issue(s):
- (1) Control Rod Drive System Operational Vulnerabilities.
INSPECTION RESULTS
Observation: Control Rod Drive System Operational Vulnerabilities 71152 Over the past year, there have been several operational vulnerabilities associated with the Control Rod Drive (CRD) system. The inspectors identified at least ten issues associated with CRD components that had the potential to impact SCRAM insertion functions of the control rods or may have placed the licensee in a single point vulnerability with respect to the CRD system. Several instances of nitrogen (N2) leaks from accumulators were noted as on-going or slow to have action taken to repair. Low accumulator N2 pressures can impact SCRAM insertion functions of the control rods. In order to maintain operability and compliance with technical specifications, operations personnel regularly repressurized the accumulators. In several instances this was noted as an operational burden.
The inspectors reviewed licensee corrective actions associated with Corrective Action QIM 50100038829, CRD-111/02-31 Valve not Able to Isolate; QIM 50100035347, CRD-111/18-31 Bonnet Instrument Block N2 Leak; and QIM 50100038062, CRD-11/14-39 Would not Isolate for Cal. The inspectors assessed the following performance attributes in their review:
- Complete and accurate identification of the problem in a timely manner commensurate with its safety significance and ease of discovery;
- Consideration of the extent of condition, generic implications, common cause, and previous occurrences;
- Evaluation and disposition of operability/functionality/reportability issues;
- Classification and prioritization of the resolution of the problem commensurate with safety significance;
- Identification of corrective actions, which were appropriately focused to correct the problem; and
- Completion of corrective actions in a timely manner commensurate with the safety significance of the issue.
The inspectors selected these samples due to the operability impact associated Control Rod Drive system; a safety significant system. Inspectors focused review of the above attributes on the licensees corrective actions associated with the above QIMs and several others. The Inspectors determined the licensee adequately addressed the issues in accordance with their corrective action process and did not identify a performance deficiency with this issue.
Observation: Potential Adverse Trends in Degrading Work Management Practices.
71152 The inspectors performed a semi-annual review of the licensee's corrective action and adverse condition monitoring programs from January 1 - June 30, 2020, for potential adverse trends. The inspectors noted several failures in work management practices which resulted in near misses associated with maintenance or planning of safety-related or emergency preparedness equipment. Based on these events, the inspectors reviewed the licensees corrective action program (QIMs 501000043571, Unexpected Response during ATWS Modification; 50150100041764, Loss of Power to 'B' Stack WRGM; and 501000043696, Potential Trend in I&C Work Planning), trend reports, major equipment problem lists, system health reports, self-assessments, and additional documents to identify trends that might indicate the existence of a more significant safety issue. Programmatic requirements and processes were also reviewed to determine whether adverse conditions related to work control and planning were being appropriately tracked, managed, and resolved. The inspectors also reviewed the licensees selection of criteria or set points for which further evaluation or action was designated to assess the health of the adverse condition monitoring program.
The inspectors determined the licensee appropriately followed their corrective action process and did not identify any significant trends that might indicate the existence of a more significant safety concern that had not been previously addressed by the licensee, nor did the inspectors identify any performance deficiency with this issue.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On October 6, 2020, the inspectors presented the integrated inspection results to Mr. T. Conboy, Site Vice President and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
501000042102
Service Water System Challenges
501000042210
WW2027 10 Tasks Moved Out of the Week
Miscellaneous
Site VP Summer Readiness Certification Letter to the CNO
05/15/2020
Procedures
B.09.03-05
345KV Substation System Operation
Work Orders
700069851
255-06-IA-1, HPCI Quarterly Pump and Valve Tests
105
700073444
255-03-IA-1-1, Core Spray Loop 'A' Quarterly Pump and
Valve Tests
Fire Plans
Fire Zone 12-A
Strategy A.3-12-A, Lower 4KV Bus Area (13 & 15)
Fire Zone 14-A
Strategy A.3-14-A, Upper 4KV Bus Area (14 & 16)
Fire Zone 23-B
Strategy A 3.23-B, Intake Structure Corridor
Fire Zone 7-C
Strategy A.3-07-C, 125V Division II Battery Room
Miscellaneous
P&ID Screen Wash, Fire and Chlorination System Intake
Structure
Work Orders
700039723
Fire Pump (P-110) Discharge Strainer
08/10/2020
700041751
Fire Detection Instrumentation Detector Sensitivity Check for
2 ft Reactor Building
08/06/2020
700069652
Verify Strainer Fitup
08/10/2020
71111.11Q Corrective Action
Documents
501000043886
V-CH.1 Found Tripped
501000043903
Condensate Pump Packing Leak
Procedures
P-506 Portable Diesel Fire Pump Test
RQ-SS-183
Procedures
NX-7823-4-8
Elem. Diagram - Primary Containment Isolation System
Corrective Action
Documents
501000042619
16A-K3D Relay Cycling
07/24/2020
501000042632,
DPIS-2-116D Out of As-Found
07/24/2020
501000042633
DPIS-2-116D Instrument Issues
07/26/2020
501000042634
DPIS-2-116D Mercury Switch Observations
07/26/2020
501000042644
Broken Phenolic Inside Relay 16A-K3B
07/25/2020
501000043686
Removal of MCC-122 from Service
08/31/2020
501000043772
WW2034 Items Excluded per AP928 App F
08/31/2020
501000043854
Fire Det S-116A Failed Sensitivity Test
09/03/2020
501000043912
Increase in Drywell Equipment Drain Sump
09/03/2020
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
50100042550
16A-K3D Relay Failing
07/21/2020
Drawings
NX-7823-4-5
Elem. Diag - Primary Containment Isolation System
NX-7823-4-8
Elem. Diag-Primary Containment Isolation System
Corrective Action
Documents
50100003960
No Appendix J Test for Instrument Replacements
501000043673
IST and Appendix J Impacts Missed in ECR 1779
501000043960
No Appendix J Test for Instrument Replacements
Miscellaneous
501000043571
Unexpected Response During ATWS Mod
601000001779
Rosemount Upgrade - SRV Tailpipe Differential Pressure
Transmitters
04/03/02020
Corrective Action
Documents
Resulting from
Inspection
501000041113
NRC Observation of 50.59 Screening
05/29/2020
Engineering
Changes
601000000402
Remove RFP Start Interlock POS-2375 and POS-2376
Miscellaneous
18-0084
50.59 Screening - Removal of Feedwater Block Valve Pump
Start Interlocks
601000002008
NRC ATWS Diversity Rule LLWL Trip Units
05/15/2020
Work Orders
700004353
97-54, 12 EDG Low Voltage Degraded Voltage Relay PMT
07/29/2020
700039948
ESW Pump Discharge Air Vent
700040227
K-1F, 16 INST and Service Air Compressor PMT
700053265
ESW Pump Basket Strainer Selector Valve
700071513
ESW Pump Basket Strainer
700072429
D-10, 15VDC Charger for 11 Battery 480 PMT
08/28/2020
Corrective Action
Documents
204062
Bases for.6.4.2 Action Entry
Work Orders
700004353
97-54, 12 EDG Low Voltage Degraded Voltage Relay
07/29/2020
70002429
D-10, 125VDC Charger for 11 Battery 480 PMT
08/28/2020
700063046
SBLC Suction Piping System Leakage Test, 0255-02-IIC-2
Standby Liquid Control Suction Piping System Leakage Test
700070951
Safety Bus Under Voltage Test, 0301 Safeguard Bus
Degraded Voltage Protection Relay Unit Functional Test
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
700071042
Drywell High Pressure Scram and Group Iso Test and Cal,
0003Drywell High Pressure Scram and Group 2, 3, and
SCTMT Isolation Test and Calibration Procedure
700071867
SBLC Quarterly Test, 0255-0211 SBLC Quarterly Pump and
Valve Tests
700072347
Safety Bus Undervoltage Calibration, 0302 Safeguard Bus
Degraded Voltage Protection - Relay Unit Calibration
700072449
SBGT B Quarterly Test, 0253-02 SBGT Quarterly Test
700076143
0006 SCRAM Discharge Volume HI Level SCRAM Test
07/31/2020
70009651
RCIC Flow Control Dynamic Test
08/12/2020
Corrective Action
Documents
36072
P-201A 11 CRD Pump Vent Valves Leak
501000038062
CRD-111/18-31 Bonnet Instrument Block N2 Leak
501000038062
CRD-111-14-39 Would not Isolate for Calibration
501000038829
CRD-111/02-31 Valve not Able to Isolate
501000041084
O.D.D. Anchor Bolt Issues
501000041764
Loss of Power to 'B' Stack WRGM
501000042736
DPIS 3-304 and 3-217 Failed Downscale
501000043571
Unexpected Response During ATWS Modification
501000043696
Potential Trend I&C Work Planning
0