IR 05000263/2022001

Generation Plant - Integrated Inspection Report 05000263/2022001

ML22126A114
Person / Time
Site:	Monticello
Issue date:	05/10/2022
From:	Hironori Peterson Region 3 Branch 3
To:	Domingos C Northern States Power Company, Minnesota
References
IR 2022001
Download: ML22126A114 (14)

Text

May 10, 2022

SUBJECT:

MONTICELLO NUCLEAR GENERATING PLANT - INTEGRATED INSPECTION REPORT 05000263/2022001

Dear Mr. Domingos:

On March 31, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Monticello Nuclear Generating Plant. On April 14, 2022, the NRC inspectors discussed the results of this inspection with Mr. S. Hafen, Plant Manager, 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, Signed by Peterson, Hironori on 05/10/22 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: 05000263/2022001 Enterprise Identifier: I-2022-001-0064 Licensee: Northern States Power Company, Minnesota Facility: Monticello Nuclear Generating Plant Location: Monticello, MN Inspection Dates: January 01, 2022 to March 31, 2022 Inspectors: C. Norton, Senior Resident Inspector A. Demeter, Reactor Engineer T. McGowan, 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

Monticello Nuclear Generating Plant began the inspection period at rated thermal power. On January 12, 2022, the licensee observed a small increase in drywell unidentified leakage. On January 23, 2022, the licensee shut down the unit to repair the source of the increased drywell leakage. On January 27, 2022, the licensee restarted the unit and reached rated thermal power on January 28, 2022. The unit remained at or near rated thermal power for the rest of the inspection period.

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 activities described in IMC 2515, Appendix D, Plant Status, conducted routine reviews using IP 71152, Problem Identification and Resolution, observed risk significant activities, and completed on-site portions of IPs. 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.

71111.01 - Adverse Weather Protection

Impending Severe Weather Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather, extreme cold temperatures, and loss of heating boiler on January 7, 2022.

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) Division 2 emergency diesel generator starting air system on January 10, 2022

(2) Division 2 emergency diesel generator fuel oil system on January 10, 2022

(3) Standby liquid control system on February 10, 2022

(4) Control ventilation system and emergency filtration train on February 10, 2022

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (7 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 2-H, west shutdown cooling area on February 25, 2022

(2) Fire Zone 1-C, reactor core isolation cooling (RCIC) room on February 25, 2022

(3) Fire Zone 1-E, high pressure core injection (HPCI) room on February 25, 2022

(4) Fire Zone 1-G, control rod drive (CRD) pump room on February 25, 2022

(5) Fire Zone 33, emergency filtration train (EFT) building third floor on February 25, 2022

(6) Fire Zone 12-A, lower 4KV Bus area (13 & 15) on February 25, 2022

(7) Fire Zone 14-A, upper 4KV Bus area (14 & 16) on February 25, 2022

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) Flood Zone RB-VI

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 reactor startup following forced outage on January 27, 2022.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated licensed simulator training session on March 28, 2022

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) High pressure coolant injection system maintenance window ending March 23, 2022

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (2 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) Risk associated with a degraded and uncompensated fire penetration seal on January 18, 2022

(2) Risk associated with increase in unidentified drywell unidentified leakage and the licensee response on January 27, 2022

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) 501000055698, CV-1729 engineering change request testing not performed

(2) 501000060413, Step change in 12 standby liquid control (SBLC) pump insulation resistance

(3) 501000060422, control room CRV/emergency filtration train system flow indicating controller indicating flow while out of service

(4) 501000060565, VV-1728, division 1 residual heat removal service water flow control valve, failed open

(5) 501000060504 Drywell particulate radioactivity monitoring system trouble alarm received

(6) 501000061772 After replacing the sight glass on P-202B, it was found to be leaking one drop of oil per minute

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) T-Mod 601000003596, leak repair on LT-3128, level transmitter for moisture separator drain tank, T-6, dump valve

(2) Scaffold program controls for long term scaffold installation

Severe Accident Management Guidelines (SAMG) Update (IP Section 03.03) (1 Sample)

(1) The inspectors verified the site's severe accident management guidelines were updated in accordance with the boiler water reactor (BWR) generic sever accident technical guidelines and validated in accordance with NEI 14-01, Emergency Response Procedures and Guidelines for Beyond Design Basis Events and Severe Accidents, Revision 1

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (6 Samples)

The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:

(1) 0255-05-1A-1-2, B RHRSW quarterly after replacing B RHRSW flow control valve positioner, work order (WO) 700095943-0120

(2) Check for leaks after code repair of B recirculation loop outboard drain valve, XR-7-2, WO 700102233-0040

(3) 0255-05-1A, A RHRSW quarterly pump and valve tests after troubleshooting A RHRSW flow control valve positioner, WO 700103303-0020

(4) Off Gas Hold Up (OGHU) Train B Condenser Level Controller PMT following work performed under engineering change request 601000000429, WO 700067435-0040

(5) Reactor water clean up 12 filter demin backwash supply following actuator overhaul, WO 700058452-0030

(6) Control rod drive pump 12 in rush current test PMT, WO 700070042-0010

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated forced outage activities from January 24, 2022 to January 27, 2022.

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance testing activities to verify system operability and/or functionality:

Surveillance Tests (other) (IP Section 03.01) (3 Samples)

(1) Secondary containment instrumentation calibration for standby gas treatment B train LCO instruments on March 3, 2022, WO 700069802-0010

(2) Fire pump exercise and fuel quantity test on March 15, 2022

(3) Low pressure core cooling pumps discharge pressure interlock instrument test and calibration division 2, WO 700099207-0010

Inservice Testing (IP Section 03.01) (2 Samples)

(1) B RHRSW quarterly pump and valve tests, WO 700095943

(2) Standby liquid control pump and valve tests on February 10, 2022

FLEX Testing (IP Section 03.02) (1 Sample)

(1) Quarterly Functional Test of number 11 120V portable diesel generator testing on February 25,

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01) ===

(1) January 1, 2021 through December 31, 2021 IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (1 Sample)

(1) January 1, 2021 through December 31, 2021

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (1 Sample)

(1) January 1, 2021 through December 31, 2021

71152A - Annual Follow-Up Problem Identification and Resolution Annual Follow-Up of Selected Issues (Section 03.03)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1) Corrective actions associated with B residual heat removal service water flow control valve oscillations at IST reference flow

(2) Corrective actions associated with partial control room ventilation isolation (Group 2)during preventive maintenance

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) EN 55708 60-day optional 10CFR50.73(a)(1) to report an invalid actuation of secondary containment relays in accordance with10CFR50.73(a)(2)(iv)(A)

INSPECTION RESULTS

Observation: Corrective Actions Associated with B Residual Heat Removal 71152A Service Water Flow Control Valve Oscillations at in Service Testing (IST)

Reference Flow The inspectors reviewed the licensee's actions to resolve residual heat removal service water (RHRSW) flow control valve oscillations occurring at the in-service testing (IST) reference flow. This was documented in QIM 501000055651, CV-1729 controller issue.

Following replacement of the 'B' residual heat removal service water system flow control valve body and internals, the valve oscillated when adjusted to the established IST reference flow value. The licensee modified the IST test procedure to provide an alternate method to establish a stable flow at the reference value and tested the 'B' division RHRSW pumps.

Subsequently, the licensee demonstrated the operability of the B RHRSW system in accordance with technical specification requirements. Later the licensee established addition IST reference values to demonstrate that the 'B' RHRSW flow control valve was operating acceptably. The inspectors identified no issues of concern.

The inspectors concluded that the licensee had appropriately addressed the issue of the valve oscillations. No findings or violations were identified.

Observation: A Preventive Maintenance Deficiency Results in an Unplanned 71152A Control Room Ventilation Isolation On November 29, 2021, upon restoration following maintenance, the division 2 refuel floor process radiation monitor signal spiked causing a partial group 2 isolation. The control room ventilation isolated and went into the recirculation mode. Investigation revealed that the spike was caused by connector degradation between the cable and the radiation monitor. This was repaired and control room ventilation was returned to normal operation.

Reviewing past plant operating experience, the licensee discovered that three separate spiking issues had occurred with the fuel pool and reactor building exhaust plenum radiation monitors in 2006. A root cause evaluation identified that routine quarterly maintenance of these radiation monitors puts strain on the cables and cable connectors. Connector degradation over time results in spiking of the detector output. A corrective action to periodically replace the cable and cable connector was put into the fuel pool and reactor building exhaust plenum process radiation monitor preventative maintenance bases.

In 2017, the cable and connector were not replaced as required by the preventative maintenance bases. This resulted in excessive cable degradation and the signal spike that initiated the partial group 2 isolation on November 29, 2021. The failure to replace the cable and cable connector in 2017 was a performance deficiency. The performance deficiency was minor because it could not be viewed as a precursor to a significant event, if left uncorrected it would not have the potential to lead to a more significant safety concern, and it was not associated with a cornerstone attribute such that it adversely affected a corner stone objective. The licensee initiated Quality Issue 501000059353 to determine how and why the cable and cable connector were not replaced as required by the preventative maintenance basis, establish the extent of condition, and implement corrective actions to ensure preventative maintenance is performed in accordance with the preventative maintenance bases.

The inspectors concluded that the licensee had taken appropriate action to address this issue. No more than minor findings or violations were identified.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

On April 14, 2022, the inspectors presented the integrated inspection results to Mr. S. Hafen, Plant Manager, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Procedures A.6 Acts of Nature 64

C.4-B.08.03A Loss of Heating Boiler 22

71111.04 Drawings NH170037 Main Control Room CRV/EFT System 84

NH36253 Standby Liquid Control System 80

Procedures 2154-14 Fuel Oil System Prestart Valve Checklist 20

2154-28 Diesel Generator Air Start System Prestart Valve Checklist 12

71111.05 Fire Plans A.3-01-C Fire Zone 1-C RCIC Room and Appendix R Cable Enclosure 11

A.3-01-E Fire Zone 1-E HPCI Room - Reactor Building Elevation 896' 9

A.3-01-G Fire Zone 1-G CRD Pump Room 5

A.3-02-H Fire Zone 2-H West Shutdown Cooling Area 10

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

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

A.3-33 Fire Zone 33 EFT Building Third Floor 12

71111.06 Drawings NF 36057 Equipment Location Reactor Building, Plans at EL 986'-6" 77

and 1001'-2"

Engineering 07-035 Internal Flooding Analysis 0

Evaluations

71111.11Q Miscellaneous SEG MT-LOR- Cycle 22B Normal/Abnormal Scenario 1

2B-01S

71111.12 Procedures 4900-01 PM for Limitorque Motor Operated Valves 48

Work Orders 700069537 MO 2067 PM 03/22/2022

700070784 ST-2052 Outlet Check Dissemble and Inspect 03/21/2022

700071743 MO 2061 PM 03/22/2022

71111.13 Corrective Action 501000059851 Temporary Fire Penetration Seal Installed Incorrectly 01/18/2021

Documents

Procedures FP-OP-ROM-02 Shutdown Safety Risk Challenge Review 1

71111.15 Corrective Action 501000036052 Oil Weep Found on P-202B Lower Glass 12/23/2019

Documents 501000055698 CV-1729 ECR Testing Not Performed 09/03/2021

501000060413 12 Standby Liquid Control Pump Insulation Resistance Step 02/09/2022

Change Since Last Surveillance

Inspection Type Designation Description or Title Revision or

Procedure Date

501000060422 FIC 9116B (Control Room CRV/EFT System) Indicating 02/09/2022

Flow While Out of Service

501000060504 DW CAM Trouble Alarm Received 02/12/2022

501000060565 CV-1728, Failed Open 02/15/2022

501000061772 Sight Glass Leaking Oil 03/29/2022

Drawings NH-46162 P&ID Primary Containment Nitrogen Control System 90

71111.18 Corrective Action 501000060572 Question on Scaffold Clearance 02/16/2022

Documents 501000060949 Long Standing Scaffold Installation 03/02/2022

Resulting from

Inspection

Engineering 601000003596 Leak Seal for 3128 03/07/2022

Evaluations

Procedures 4 AWI-08.16.01 Monticello Emergency Operating Procedure and 13

Beyond-Design-Basis Guideline Maintenance Program

A.7-SAMG-01 RPV and Primary Containment Injection (Modes 1-4) 10

A.7-SAMG-02 RPV, Containment, and Radioactivity Release Control 10

(Modes 1-4)

A.7-SAMG-03 Refueling (Mode 5) 4

C.5-GM-02.01 Plant Specific Technical Guidelines 25

C.5-GM-02.02 Plant Specific technical Guidelines Appendix A 21

FP-MA-FSC-01 Scaffolding 0

B.06.01-06 Operations Manual Section: Turbine 13

71111.19 Work Orders 700058452-0030 12 Reactor Water Clean Up Filter Demin Backwash Supply 02/25/2022

700067435-0040 Off Gas Hold Up Train B Condenser Level Controller PMT 02/23/2022

700070042-0010 AC Motor Online (EMAX) Testing 03/03/2022

700095943-0130 12 RHR HX RHRSW Outlet 01/20/2022

700102233-0040 B Recirculation Pump Loop Drain 01/27/2022

700103303-0020 CV-1728, PMT 02/16/2022

71111.20 Miscellaneous 602000020082 Shutdown Safety Risk Challenge Review 01/25/2022

Procedures 2100 Master Systems Checklist 19

20 Plant Prestart Checklist 14

2145 RHR System Venting 19

2150 Plant Prestart Checklist 51

Inspection Type Designation Description or Title Revision or

Procedure Date

2167 Plant Startup 105

2167-03 Startup Checklist Mode 4 to Mode 2 21

9111-05 Decay Heat Removal Hardening 5

B.01.04-05 Shutdown of One Reactor Recirculation Pump with Reactor 59

at Power

Work Orders 700102233-0010 XR-7-2, Replace Body to Bonnet Gasket 3

700103063 ASME Section XI Repair /Replacement Plan 9

70102233-0010 XR-7-2, Replace Body to Bonnet Gasket 3

70102233-0020 XR-7-2 Body to Bonnet Sealing Surface Repair 0

70102233-0035 XR_7-2, Check Bonnet Torque 0

71111.22 Procedures 0255-02-III Standby Liquid Control Pump and Valve Tests 68

255-05-1A-1-2 B RHRSW Quarterly Pump and Valve Tests 91

261 Fire Pump Exercise and Fuel Quantity Check 60

OSP-APR-0037- APRS-Low Pressure Core Cooling Pumps Discharge 1

Pressure Interlock Instrument Test and Calibration-Division 2

OSP-BDB-0297 G-101 Number 11 120V Portable Diesel Generator Testing 4

OSP-BDB-0398 G-102 12 120V Portable Diesel Generator Testing 5

Work Orders 700069802-0010 Secondary Containment Instrument Calibration - Standby 03/03/2022

Gas Treatment B Train

700095943-0150 CV-1729 Perform Flow Test 01/22/2022

71151 Miscellaneous QF0445 Unplanned Scrams per 7000 Critical Hours, Monthly 18

Submission Forms (January 1, 2021 through December 31,

21)

QF0445 Unplanned Scrams with Complications (USwC), Monthly 18

Submission Forms (January 1, 2021 through December 31,

21)

QF0445 Unplanned Power Changes per 7000 Critical Hours, Monthly 18

Submission Forms (January 1, 2021 through December 31,

21)

71152A Corrective Action 501000055651 CV-1729 Controller Issue 09/01/2021

Documents

Procedures 3108 Pump/Valve/Instrument Record of Corrective Action 01/22/2022

71152S Corrective Action 501000058690 RM-17-453B Spiked High 11/29/2021

Documents

Inspection Type Designation Description or Title Revision or

Procedure Date

Corrective Action 501000059353 PMCR Not Implemented as Requested 12/28/2021

Documents

Resulting from

Inspection

71153 Procedures FP-OP-REP-01 Reactor Plant Event Notification Worksheet 4

2