IR 05000263/2020003

Integrated Inspection Report 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: DPR-22 Report Number: 05000263/2020003 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 Enclosure

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.

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:

(1) Unexpected response during anticipated transient without scram (ATWS) mod on August 27, 2020

(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,

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 71152 Practices.

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 Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action 501000042102 Service Water System Challenges 0

Documents 501000042210 WW2027 10 Tasks Moved Out of the Week 0

Miscellaneous Site VP Summer Readiness Certification Letter to the CNO 05/15/2020

Procedures B.09.03-05 345KV Substation System Operation 44

71111.04 Work Orders 700069851 0255-06-IA-1, HPCI Quarterly Pump and Valve Tests 105

700073444 0255-03-IA-1-1, Core Spray Loop 'A' Quarterly Pump and 65

Valve Tests

71111.05 Fire Plans Fire Zone 12-A Strategy A.3-12-A, Lower 4KV Bus Area (13 & 15) 19

Fire Zone 14-A Strategy A.3-14-A, Upper 4KV Bus Area (14 & 16) 18

Fire Zone 23-B Strategy A 3.23-B, Intake Structure Corridor 10

Fire Zone 7-C Strategy A.3-07-C, 125V Division II Battery Room 9

71111.06 Miscellaneous P&ID Screen Wash, Fire and Chlorination System Intake 95

Structure

Work Orders 700039723 Fire Pump (P-110) Discharge Strainer 08/10/2020

700041751 Fire Detection Instrumentation Detector Sensitivity Check for 08/06/2020

2 ft Reactor Building

700069652 Verify Strainer Fitup 08/10/2020

71111.11Q Corrective Action 501000043886 V-CH.1 Found Tripped 0

Documents 501000043903 Condensate Pump Packing Leak 0

Procedures OSP-FIR-0608 P-506 Portable Diesel Fire Pump Test 7

RQ-SS-183 MT Simulator LOR Exam 0

71111.12 Procedures NX-7823-4-8 Elem. Diagram - Primary Containment Isolation System 7

71111.13 Corrective Action 501000042619 16A-K3D Relay Cycling 07/24/2020

Documents 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 Type Designation Description or Title Revision or

Procedure Date

50100042550 16A-K3D Relay Failing 07/21/2020

Drawings NX-7823-4-5 Elem. Diag - Primary Containment Isolation System 79

NX-7823-4-8 Elem. Diag-Primary Containment Isolation System 77

71111.15 Corrective Action 50100003960 No Appendix J Test for Instrument Replacements 0

Documents 501000043673 IST and Appendix J Impacts Missed in ECR 1779 0

501000043960 No Appendix J Test for Instrument Replacements 0

Miscellaneous ACE Unexpected Response During ATWS Mod 0

501000043571

ECR Rosemount Upgrade - SRV Tailpipe Differential Pressure 04/03/02020

601000001779 Transmitters

71111.18 Corrective Action 501000041113 NRC Observation of 50.59 Screening 05/29/2020

Documents

Resulting from

Inspection

Engineering 601000000402 Remove RFP Start Interlock POS-2375 and POS-2376 0

Changes

Miscellaneous 18-0084 50.59 Screening - Removal of Feedwater Block Valve Pump 2

Start Interlocks

ECR NRC ATWS Diversity Rule LLWL Trip Units 05/15/2020

601000002008

71111.19 Work Orders 700004353 97-54, 12 EDG Low Voltage Degraded Voltage Relay PMT 07/29/2020

700039948 11 ESW Pump Discharge Air Vent 1

700040227 K-1F, 16 INST and Service Air Compressor PMT 0

700053265 11 ESW Pump Basket Strainer Selector Valve 3

700071513 ESW Pump Basket Strainer 1

700072429 D-10, 15VDC Charger for 11 Battery 480 PMT 08/28/2020

71111.22 Corrective Action 01204062 Bases for .6.4.2 Action Entry 0

Documents

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 6

Standby Liquid Control Suction Piping System Leakage Test

700070951 Safety Bus Under Voltage Test, 0301 Safeguard Bus 44

Degraded Voltage Protection Relay Unit Functional Test

Inspection Type Designation Description or Title Revision or

Procedure Date

700071042 Drywell High Pressure Scram and Group Iso Test and Cal, 36

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 67

Valve Tests

700072347 Safety Bus Undervoltage Calibration, 0302 Safeguard Bus 35

Degraded Voltage Protection - Relay Unit Calibration

700072449 SBGT B Quarterly Test, 0253-02 SBGT Quarterly Test 57

700076143 0006 SCRAM Discharge Volume HI Level SCRAM Test 07/31/2020

70009651 RCIC Flow Control Dynamic Test 08/12/2020

71152 Corrective Action 36072 P-201A 11 CRD Pump Vent Valves Leak 0

Documents 501000038062 CRD-111/18-31 Bonnet Instrument Block N2 Leak 0

501000038062 CRD-111-14-39 Would not Isolate for Calibration 0

501000038829 CRD-111/02-31 Valve not Able to Isolate 0

501000041084 O.D.D. Anchor Bolt Issues 0

501000041764 Loss of Power to 'B' Stack WRGM 0

501000042736 DPIS 3-304 and 3-217 Failed Downscale 0

501000043571 Unexpected Response During ATWS Modification 0

501000043696 Potential Trend I&C Work Planning 0

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