IR 05000461/2022001
| ML22118A600 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/28/2022 |
| From: | Kenneth Riemer NRC/RGN-III/DRP/B1 |
| To: | Rhoades D Constellation Energy Generation |
| References | |
| IR 2022001 | |
| Download: ML22118A600 (15) | |
Text
SUBJECT:
CLINTON POWER STATION - INTEGRATED INSPECTION REPORT 05000461/2022001
Dear Mr. Rhoades:
On March 31, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Clinton Power Station and discussed the results of this inspection with Mr. T. Chalmers, 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, Kenneth R. Riemer, Chief Branch 1 Division of Reactor Projects Docket No. 05000461 License No. NPF-62 Enclosure:
As stated cc w/ encl: Distribution via LISTSERV April 28, 2022 Signed by Riemer, Kenneth on 04/28/22
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Clinton Power Station, 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
Unit 1 began the inspection period at rated thermal power. On January 15, 2022, the unit shut down for a maintenance outage to repair the redundant reactor pressure control system. The unit was returned to rated thermal power on January 19, 2022, and remained at or near rated thermal power for the remainder 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.
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 seasonal hot temperatures for the following systems:
Action Request (AR) 4481515, "Main Power Transformer 'B' for Summer Readiness,"
on March 31, 2022
External Flooding Sample (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated that flood protection barriers, mitigation plans, procedures, and equipment are consistent with the licensees design requirements and risk analysis assumptions for coping with external flooding on March 25, 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 on March 23, 2022 (2)
'B' standby gas treatment train on March 23, 2022 (3)
'A' and 'B' standby liquid control on March 28, 2022 (4)reactor core isolation cooling on March 28, 2022
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the high-pressure core spray system on February 20 and 22, 2022.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (10 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 T-1(h), turbine building turbine auxiliaries area, elevation 762'-0" on January 28, 2022
- (2) Fire Zone F-1(a,b,c,d,e,f,g,h,i,p), fuel building basement area, elevation 712'-0" on February 13, 2022
- (3) Fire Zone A-1(b,d,e), auxiliary building general access and south hall areas, elevation 707'-0" on February 13, 2022
- (4) Fire Zone D-2, Division 1 diesel generator fuel tank room, elevations 712'-0" and 719'-0"; and Fire Zone D-5b, Division 1 diesel generator day tank room, elevation 737'-0" on February 13 and 14, 2022
- (5) Fire Zone D-3, Division 2 diesel generator fuel tank room, elevations 712'-0" and 719'-0"; and Fire Zone D-6b, Division 2 diesel generator day tank room, elevation 737'-0" on February 13 and 14, 2022
- (6) Fire Zone D-1, Division 3 diesel generator fuel tank room, elevations 712'-0" and 719'-0"; and Fire Zone D-4b, Division 3 diesel generator day tank room, elevation 737'-0" on February 13 and 14, 2022
- (7) Fire Zone A2 A-2a, reactor core isolation cooling pump room, elevation 707'-6" on February 17, 2022
- (8) Fire Zone A-3b, residual heat removal 'C' pump room, elevation 707'-6" on February 20, 2022
- (9) Fire Zone A-2c, low pressure core spray pump room, elevations 707'-6" and 712'-0";
and Fire Zone A-3c, floor drains and hallway, elevation 712'-0" on February 20, 2022
- (10) Fire Zone F-1b, high pressure core spray pump room, elevation 712'-0" on February 20, 2022
Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the onsite fire brigade training and performance during an unannounced fire drill on March 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) north auxiliary building corridor
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 plant start-up on January 18, 2022.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated just-in-time simulator training for 1B21F022A 'B' solenoid work on January 26, 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 remain capable of performing their intended function:
(1)emergency reserve auxiliary transformer automatic load tap changer failure to tap on February 19, 2022
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (4 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:
- (2) WO 5133895, "Fire Pump 'B' Capacity and Controls Test with Fire Pump 'A' Non-Functional"
- (3) WO 1783943, "Emergency Reserve Aux Transformer Risk Informed Completion Time"
- (4) WO 4935719, "Reactor Core Isolation Cooling Water Leg Pump"
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) AR 4471456, "828' Containment Personnel Door"
- (2) AR 4473382, "Inboard MSIV 'A' Solenoid 'B' Current Reading Low"
- (3) AR 4479303, "4160V 1A1 Bus Voltage Rose Above 4300 Volts"
- (4) AR 4486876, "ERAT [emergency reserve auxiliary transformer] HIPOT Testing Failure"
- (5) AR 4487680, "Teletower in RCIC [reactor core isolation cooling] Room"
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)
The inspectors evaluated the following temporary or permanent modifications:
(1)emergency reserve aux transformer reverse power bias permanent modification
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) WO 5225181-01, "MSIV 'A' Solenoid"
- (2) WO 5148135-04, "1E12-F003B"
- (3) WO 5235666-01, "CPS 9038.70 SC Rad Monitoring Source Checks (0RIX-PR001)"
- (4) WO 5234503-01, "ERAT VVR Reverse Power Reset"
- (5) WO 4935719-02, "RCIC Water Leg Pump"
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) Clinton Power Station (CPS) 9071.02, "Diesel Fire Pump Capacity Checks," on February 12, 2022
- (2) CPS 9054.02, "Reactor Core Isolation Cooling Valve Operability," on March 25, 2022
Inservice Testing (IP Section 03.01) (3 Samples)
- (1) CPS 9053.07, "1E22-C002B RHR 'B' Pump Operability Test," WO 5213928
- (2) CPS 9051.01, "1E22-C001 HPCS [high pressure core spray] Comprehensive Pump Test," WO 5088860
- (3) CPS 9015.01, "Standby Liquid Control Pump 'B'," WO 5083704
FLEX Testing (IP Section 03.02) (1 Sample)
(1)
'B' FLEX generator, on February 8,
RADIATION SAFETY
71124.03 - In-Plant Airborne Radioactivity Control and Mitigation
Permanent Ventilation Systems (IP Section 03.01) (2 Samples)
The inspectors evaluated the configuration of the following permanently installed ventilation systems:
(1)standby gas treatment system (2)control room makeup ventilation
Use of Respiratory Protection Devices (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated the licensees use of respiratory protection devices.
Self-Contained Breathing Apparatus for Emergency Use (IP Section 03.04) (1 Sample)
- (1) The inspectors evaluated the licensees use and maintenance of self-contained breathing apparatuses.
71124.04 - Occupational Dose Assessment
Source Term Characterization (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated licensee performance as it pertains to radioactive source term characterization.
External Dosimetry (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated how the licensee processes, stores, and uses external dosimetry.
Special Dosimetric Situations (IP Section 03.04) (2 Samples)
The inspectors evaluated the following special dosimetric situations:
(1)declared pregnant worker dose assessments performed in 2021 (2)effective dose equivalent assessments performed for in-service inspection activities located inside the Unit 1 containment bioshield during the C1R20 refueling outage
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) Unit 1 (January 1, 2021 through December 31, 2021)
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (1 Sample)
- (1) Unit 1 (January 1, 2021 through December 31, 2021)
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (1 Sample)
- (1) Unit 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)fire pump work management issues
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)
(1)potential adverse trend with reactive management
INSPECTION RESULTS
Observation: Work Management Issues with Fire Pump Maintenance 71152A The inspectors performed an annual review of the licensee's work management of fire pump maintenance that might indicate the existence of a more significant safety issue. Clinton Power Station has two fire pumps, both of which are diesel powered. The A fire pump has been out of service since August of 2021 through the end of the first quarter of 2022. During this period, the inspectors identified two issues with the licensees inability to effectively plan and execute work activities as described in WC-AA-101-1002, On-Line Scheduling Process.
First, on November 26, 2021, the licensee failed to review the fire pump impairment prior to exceeding 90 days of being impaired as specified in CPS 1893.01, Fire Protection Impairment Reporting, Section 6.1. This issue was entered into the CAP as AR 4463176 to document the failure to track, repair, and close fire impairments in a timely manner.
Second, on February 10, 2022, the licensee scheduled a planned test of the B fire pump with the A pump being out of service, which was contrary to CPS 9071.02, Diesel Fire Pump Capacity Checks, Section 5.5. Both of these issues did not have significant effect on plant operation but were considered examples of inadequate work management. The licensee subsequently revised the affected procedures to add additional guidance. The inspectors had no concerns with the licensees actions.
No findings or violations were identified.
Observation: Potential Adverse Trend with Reactive Management 71152S The inspectors performed a semiannual review of the licensee's reactivity management and identified a potential adverse trend occurring since October 27, 2021, and continuing through the 1st quarter of 2022. This period included planned shutdowns for refueling outage C1R20 and maintenance outages C1M24 and -25, and some maintenance-related power reductions.
During this period, there were several emergent equipment issues affecting reactor pressure control, source range instrumentation, and main steam isolation valve control. These issues had minimal risk impacts to the initiating events safety cornerstone, mostly due to the redundancy aspect of functions. The repair times of each were varied with some taking multiple discovery, planning, and execution efforts that both extended the duration of unavailability and impacted planned work weeks, pushing back other preventative and corrective maintenance. These delays resulted, in part, due to the licensee mismanaging the work scope by changing priorities or work scope and deferring priorities. The inspectors also reviewed equipment-related process and management issues that placed control room personnel into knowledge-based decision-making positions with regarding reactivity management.
The first example was recurring instances of reactor water cleanup differential flow isolation, generally coincidental with the reactor startup. Specifically, expected flow instabilities during startup, result in reactor water level changes requiring plant operators having to take actions to stabilize conditions. Although this has not resulted in any significant events, this condition has existed for several years and the licensee has thus far been unable to resolve the issue.
The second example occurred on October 30, 2021, during reactor startup. In Mode 1, with reactor power between 16.7 and 21.6 percent, reactor operators were unable to withdraw control rod 16-25 past position 08 with normal drive differential pressure. To improve rod performance, the reactor operators attempted to vent the control rod's withdraw header to remove entrained air in the withdraw line. This resulted in an unexpected and complete insertion of control rod 16-25. Although a venting procedure exists, the risks of venting while in this configuration were not considered prior to taking the action. As a result, the operators had to deal with the reactivity consequences from the control rod insertion. Although this was a non-conservative action, it did not put the plant in an unanalyzed or regulatorily prohibited condition.
The inspectors considered both of the above events as findings of minor significance, since neither had any adverse effect on plant operation. Both issues were entered into the CAP as ARs 4457122 and 4472403 to document the ongoing regulatory concerns with reactivity management spanning several years.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On March 31, 2022, the inspectors presented the integrated inspection results to Mr. T. Chalmers, Site Vice President, and other members of the licensee staff.
On March 18, 2022, the inspectors presented the radiation protection baseline inspection results to Mr. T. Chalmers, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Oil Leak from 1MP04EB-531-6 Flange
09/29/2021
Mulitple Leaks Found on MPT A and MPT B
10/06/2021
New Leak Identified on the MPT B
10/12/2021
EOID: MPT B Oil Leak Increased to 70 dpm
03/01/2022
Corrective Action
Documents
MPT B Oil Leak Rate Changed to 95 dpm
03/30/2022
CPS 3309.01
High Pressure Core Spray Valve Lineup
11b
3310.01E001
Reactor Core Isolation Cooling Electrical Lineup
3310.01V001
Reactor Core Isolation Cooling Valve Lineup
3314.01E001
Standby Liquid Control Electrical Lineup
9a
Procedures
3314.01V001
Standby Liquid Control Valve Lineup
10a
1893.04M100
707 Auxiliary: General Access Area Prefire Plan
5a
1893.04M101
707 to 712 Auxiliary: LPCS Pump Room Prefire Plan
5a
1893.04M103
707 Auxiliary: RCIC Pump Room Prefire Plan
5a
1893.04M105
707 Auxiliary: RHR 'C' Pump Room Prefire Plan
5a
1893.04M106
2 Auxiliary: Floor Drain Pump Rooms Prefire Plan
5a
1893.04M107
707 Auxiliary: South Hallway Prefire Plan
1a
1893.04M400
2 Fuel: Basement Prefire Plan
5a
1893.04M500
2 Diesel Generator: Div 3 Diesel Fuel Tank Room Prefire
Plan
5b
Fire Plans
1893.04M501
2 Diesel Generator: Div 1 Diesel Fuel Tank Room Prefire
Plan
5b
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
1893.04M502
2 Diesel Generator: Div 2 Diesel Fuel Tank Room Prefire
Plan
6a
1893.04M510
737 Diesel Generator: Div 3 Diesel Generator & Day Tank
Room Prefire Plan
6c
1893.04M511
737 Diesel Generator: Div 1 Diesel Generator & Day Tank
Room Prefire Plan
6c
1893.04M512
737 Diesel Generator: Div 2 Diesel Generator & Day Tank
Room Prefire Plan
7b
1893.04M720
2 Turbine: Turbine Auxiliaries Prefire Plan
6c
Miscellaneous
CPS Plan of the
Day Meeting
Package
System Operability/Availability Report
2/10/2022
CPS 1893.01
Fire Protection Impairment Reporting
2b
Procedures
CPS 9071.02
Diesel Fire Pump Capacity Checks
2e
ERAT HIPOT Testing
03/22/2022
Work Orders
Inboard MSIV 'A' Solenoid 'B' Current Reading Low
01/25/2022
28 Containment Personnel Door Interlock Failed
01/12/2022
Inboard MSIV 'A' Solenoid 'B' Current Reading Low
01/22/2022
Unsatisfactory HIPOT Test Between Switch ER4 and ER14
03/23/2022
NRC ID: Teletower in RCIC Room
03/27/2022
Division 2 DG Air Start Motor Oilers Need Replaced
04/02/2022
Corrective Action
Documents
Div 2 DG 12 & 16 Cyl Fuel Priming Pump Motors Sparking
04/02/2022
Engineering
Changes
ERAT Voltage Regulator Relay Setting Enhancement
03/24/2022
03/27/2022
ERAT VVR Reverse Power Reset
03/24/2022
Work Orders
CPS 9038.70 SC Rad Monitoring Source Checks
03/03/2022
CPS 9015.01
SLC Pump B Operability
2f
CPS 9054.01
RCIC System Operability Check
CPS 9054.02
Reactor Core Isolation Cooling Valve Operability
43c
Procedures
CPS 9071.02
Diesel Fire Pump B Capacity Check
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Orders
OP 9053.07 RHR 'B' Pump Operability Test
03/04/2022
Inconsistency with Respirator Fit Test
03/16/2022
Spectacle Kit Usage During Fit Test
03/22/2022
Corrective Action
Documents
Resulting from
Inspection
NRC Interview Regarding WO 4835532 Ventilation Test
03/25/2022
Breathing Air Grade D Test Analysis for January 1, 2020
through December 30, 2021
Various
Respiratory Protection Inventory and Inspection Documents
(October through December 2021)
Various
SRO and RO Respiratory Protection Records for Dayshift
03/18/2022
Various
SRO and RO Spectacle Kit Availability
03/18/2022
SCBA Annual Flow Verification Tests for Kits 15, 35, and 58
09/21/2021
Miscellaneous
100518-0
Landauer NVLAP Ionizing Radiation Accreditation
01/01/2022
Respiratory Protection Program
Selection of Respiratory Protection for Non-Radiological Use
Controlled Negative Pressure (CNP) Fit Testing
Maintenance, Care, and Inspection of Respiratory Protective
Equipment
Procedures
Inspection and Use of the Mururoa V4 MTH2, V4F1 and
V4F1R Air Supplied Suits
Self-Assessments NOSA-CPS-21-
Radiation Protection Audit Report
11/01/2021
Control Room HVAC Makeup Filter Package A
06/15/2020
Work Orders
Perform VG A Charcoal/Heater/HEPA
Surveillance Testing - Standby Gas Treatment System
Charcoal Adsorber A
2/20/2022
Quality Assurance Tests of the Accuscan Whole Body
Counter
03/14/2022
Landauer Control Subtraction Validation Rules
Undated
CL-1-21-00518 EDEX Individual Dose Records
Various
2056
Personnel Exposure Investigation - DLR/SRD Discrepancy
10/24/2021
18073
Personnel Exposure Investigation - SRD Malfunction
09/27/2021
Miscellaneous
CL-1-21-00518
Multiple Dosimetry EDE Evaluation Sheet - 752' and 777'
Undated
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Elevation Drywell Bioshield ISI
L89141
CFR 61 Analysis of Dry Active Waste
09/15/2020
External Dose Control Program Description
Procedures
Dosimetry Issue, Usage and Control
Fastscan and Accuscan Whole Body Count Analysis
Performed 03/14/2022 at 1200
03/14/2022
Unit 1 Drywell Inside the Bioshield Surveys from
09/30/2021 through 10/03/2021
Various
Radiation
Surveys
Surveys of Unit 1 Drywell Inside the Bioshield from
September 19-26, 2019
Various