IR 05000237/2021003
| ML21305A053 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/01/2021 |
| From: | Kenneth Riemer NRC/RGN-III/DRP/B1 |
| To: | Rhoades D Exelon Generation Co LLC, Exelon Nuclear |
| References | |
| IR 2021003 | |
| Download: ML21305A053 (15) | |
Text
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000237/2021003 AND 05000249/2021003
Dear Mr. Rhoades:
On September 30, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Dresden Nuclear Power Station, Units 2 and 3. On October 7, 2021, the NRC inspectors discussed the results of this inspection with Mr. P. Karaba, 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 Nos. 05000237 and 05000249 License Nos. DPR-19 and DPR-25
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000237 and 05000249
License Numbers:
Report Numbers:
05000237/2021003 and 05000249/2021003
Enterprise Identifier:
I-2021-003-0082
Licensee:
Exelon Generation Co., LLC
Facility:
Dresden Nuclear Power Station, Units 2 and 3
Location:
Morris, IL
Inspection Dates:
July 01, 2021 to September 30, 2021
Inspectors:
M. Domke, Resident Inspector
G. Edwards, Health Physicist
R. Elliott, Acting Senior Resident Inspector
A. Nguyen, Senior Resident Inspector
M. Porfirio, Illinois Emergency Management Agency
Approved By:
Kenneth R. Riemer, Chief
Branch 1
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Dresden Nuclear Power Station, Units 2 and 3, 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 2 began the inspection period at rated thermal power. On July 17, 2021, the unit was down powered to 74 percent to perform a quarterly control rod sequence exchange and routine testing. The unit was returned to rated thermal power on July 18, 2021. On August 15, 2021, the unit was down powered to 82 percent to perform an end of cycle control rod sequence exchange. The unit was returned to rated thermal power on August 16, 2021. On September 4, 2021, the unit was down powered to 80 percent to perform an end of cycle control rod sequence exchange. The unit was returned to rated thermal power on September 5, 2021 and remained at or near rated thermal power for the remainder of the inspection period.
Unit 3 began the inspection period at rated thermal power. On September 18, 2021, the unit was down powered to 85 percent to perform a quarterly control rod sequence exchange and conduct control rod drive testing. The unit was returned to rated thermal power on September 19, 2021 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 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 and regional 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, increasing the amount of time on-site as local COVID-19 conditions permitted.
As part of their on-site activities, resident inspectors conducted plant status activities as described in IMC 2515, Appendix D, Plant Status, and conducted routine reviews using IP 71152, Problem Identification and Resolution, 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
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (1 Sample)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 3 high pressure core injection system partial walkdown August 17, 2021
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the Unit 3 low pressure coolant injection and containment cooling systems on July 22, 2021.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (2 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) FZ 8.2.4, Unit 2 cable tunnel east and Unit 3 cable tunnel west elevation 502' on July 12, 2021
- (2) FZ 11.3 Unit 1 crib house on July 21, 2021
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 in Unit 3 station black out diesel generator room on September 20, 2021.
71111.06 - Flood Protection Measures
Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)
- (1) Unit 2 cable tunnel east and Unit 3 cable tunnel west, elevation 502' on July 12, 2021
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated the crew in dealing with a low-pressure core injection corner room leak, a control rod drift, a feedwater leak in drywell, and an anticipated transient without a scram condition in the simulator on September 16, 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) Containment cooling function to maintain design requirement by closed cooling service water and low-pressure core injection systems on September 28, 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:
- (1) Commercially dedicated ball check valve for Unit 3 reactor building exhaust outlet isolation damper per WO 015200503
Commercially dedicated junction box to overhaul Unit 3 hydraulic control unit during refueling outage D3R25 per WO 04946153
Commercially dedicated hoses to replace the pilot bellows sensing line on Unit 3 Target Rock relief and pilot assembly per WO 04890312
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) Unit 2/3 elevated risk due 2/3 diesel fire pump maintenance on July 21, 2021
- (2) Line 1222 switching opened circuit breaker 10-11 which temporarily provides only one breaker for Unit 3 main generator output on September 9, 2021 Be
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) Drywall temperatures thermal elements TE 3-5741 and TE 3-1053-B above environmental qualification limits, AR 4434751
- (2) A small amount of water was drained from the conduit on 2-0261-35A, AR 4437971
- (3) Control room emergency ventilation system refrigerant control unit return pipe through-wall leak at weld connection between 2/3-3999-332 and 2/3-39248-3, AR 4438564
- (4) Unit 2 station blackout secondary ventilation fan did not start, AR 4438968
- (5) Flex barge 'A' fuel replacement, AR 4437501
- (6) Unit 3 high pressure coolant injection pump alert level vibrations on outboard booster pump axial 10A location on September 9, 2021 per WO 5164996-01, AR 4445418
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (2 Samples)
The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:
- (1) Repair 'B' control room emergency ventilation valve 2/3-399-332 to 2/3-39248-3" pipe leak on August 5, 2021, Work Order 05175915-01
- (2) Unit 2 high pressure core injection trip during quarterly surveillance solenoid valves SV8 and SV12 replacements on September 14, 2021, Work Order 05176215-05
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) Unit 3 quarterly high pressure coolant injection system operability on September 8, 2021 per work order 05164996
- (2) Common unit quarterly 2/3 diesel generator cooling water IST surveillance on September 27, 2021 per work order 05168530-01
- (3) Quarterly core spray pump test with torus available for IST data surveillance on July 27, 2021 per work order 05149543
- (4) Unit 3 standby liquid control system quarterly 3B pump test for the in-service testing program on August 19, 2021 per work order 05158064-01
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) Unit 3 quarterly containment cooling service water pump 3B IST surveillance on September 7, 2021 per work order 05164416
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.01-02.03) (1 Sample)
- (1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes.
Eval No. 20-74 Emergency Action Levels for Dresden Station, EP-AA-1004, Addendum 3
Eval No. 20-86 Dresden Station Radiological Emergency Plan This evaluation does not constitute NRC approval.
71114.06 - Drill Evaluation
Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)
The inspectors evaluated:
- (1) Licensee Operator requalification training held in the training simulator on September 16,
RADIATION SAFETY
71124.02 - Occupational ALARA Planning and Controls
Radiological Work Planning (IP Section 03.01) (3 Samples)
The inspectors evaluated the licensees radiological work planning.
- (1) Radiation Work Permit DR-03-20-00901 for Unit 3 Reactor Disassembly/Reassembly Activities during the Fall 2020 Outage (D3R26).
- (2) Radiation Work Permit DR-03-20-00506 for Unit 3 Drywell Scaffold Installation/Removal Activities during the Fall 2020 Outage (D3R26).
- (3) Radiation Work Permit DR-03-20-00520 for Unit 3 Drywell Snubber Activities during the Fall 2020 Outage (D3R26).
71124.07 - Radiological Environmental Monitoring Program
Radiological Environmental Monitoring Program (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the implementation of the licensees radiological environmental monitoring program.
GPI Implementation (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated the licensees implementation of the Groundwater Protection Initiative program to identify incomplete or discontinued program elements.
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS08: Heat Removal Systems (IP Section 02.07)===
- (1) Unit 2 (July 1, 2020 - June 30, 2021)
- (2) Unit 3 (July 1, 2020 - June 30, 2021)
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
- (1) Unit 2 (July 1, 2020 - June 30, 2021)
- (2) Unit 3 (July 1, 2020 - June 30, 2021)
MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)
- (1) Unit 2 (July 1, 2020 - June 30, 2021)
- (2) Unit 3 (July 1, 2020 - June 30, 2021)
71152 - Problem Identification and Resolution
Annual Follow-Up of Selected Issues (IP Section 02.03) (2 Samples)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) Unit 3 'A' MSL inboard MSIV partially closed, IR 4425857
- (2) Unit 2 LCPI "B" suction line vent valve 2-1501-79B packing leak beyond owner established limits per ASME Boiler & Pressure Vessel Code Section XI IWB-3142, IR
INSPECTION RESULTS
Observation: Unit 3 'A' MSL Inboard MSIV Partially Closed 71152 The inspectors reviewed Action Request 4425857, "U3 'A' MSL Inboard MSIV Partially Closed" as a sample for annual selected issue(s) for follow-up focusing on the following performance attributes of IP 71152:
complete, accurate, and timely documentation in the corrective action program
evaluation and timely disposition of operability and reportability issues
consideration of the extent of condition and cause, generic implications, common cause, and previous occurrences
evaluation and timely disposition of operability and 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
completion of corrective actions in a timely manner commensurate with the safety significance of the issue
identification of negative trends associated with human or equipment performance that can potentially impact nuclear safety
operating experience is adequately evaluated for applicability and applicable lesson learned are communicated to appropriate organizations and implemented Inspectors notified the licensee of a concern about potential misclassification of activities associated with Unit 3 inboard MSIV "A" closing and subsequent piping replacements due to cracked threads in the MSIV manifold block. Interviews with the licensee determined their actions taken near the MSIV failure date 5/26/2021 were viewed as "rework" in accordance with CC-AA-11. The 1 1/2-inch nominal size pipe had damaged threads that did not conform (cracked) and were not providing pressure boundary required of the pneumatic pipe. The licensee added a new section of threaded pipe and welded this extension using a socket coupling to existing, halved pipe. The licensee added this socket and two welds and an extended threaded 1 1/2 section and determined the activity was rework instead of repair.
The "rework" designation allowed the licensee to perform work using its work order processes, whereas a "repair" designation would have required the engineering change process. The licensee documented Inspectors' concerns in action request 4434692.
Observation: Valve Packing Leak on 2-1501-79B 71152 The inspectors reviewed Action Request 1546806, "Valve Packing Leak on 2-1501-79B" as a sample for annual selected issue(s) for follow-up focusing on the following performance attributes of IP 71152:
complete, accurate, and timely documentation in the corrective action program
evaluation and timely disposition of operability and reportability issues
consideration of the extent of condition and cause, generic implications, common cause, and previous occurrences
evaluation and timely disposition of operability and 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
completion of corrective actions in a timely manner commensurate with the safety significance of the issue identification of negative trends associated with human or equipment performance that can potentially impact nuclear safety
operating experience is adequately evaluated for applicability and applicable lesson learned are communicated to appropriate organizations and implemented The licensee identified a class 2 valve packing leak on component 2-1501-79B at a rate of 12 drops per minute (dpm) in 2013. Inspectors observed licensee defined ASME code limitations for class 2 leakage as less than 20 drops per minute, and Inspector walkdowns identified leakage at 2-1501-79B beyond 20 drops per minute.
This a packing leak that would typically worsen but documentation shows either improvement (0dpm) or stagnation (12dpm) while Inspector walkdowns showed exceedance of owner defined ASME acceptance criteria between 40-80 dpm beginning July 2021.
The licensee appears compliant with ASME Section XI and 10CFR50.55a because required examinations were performed at required periodicities even if no leakage was identified.
ASME code interpretation XI-1-92-03 supports this notion of compliance. The licensee is tracking completion of Inspector identified leakage beyond owner defined limits by AR 4446281, "NRC Question."
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On October 7, 2021, the inspectors presented the integrated inspection results to Mr. P. Karaba, Site Vice President, and other members of the licensee staff.
On August 6, 2021, the inspectors presented the radiation protection inspection results to Mr. P. Boyle, Plant Manager, and other members of the licensee staff.
On October 1, 2021, the inspectors presented the EPlan and EAL Change inspection results to Mr. D. Moore, Senior Manager, Emergency Preparedness, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
4436081
NRC Inspector Walkdown Items
07/20/2021
4436299
NRC Inspector Walkdown Items
07/21/2021
Corrective Action
Documents
Resulting from
Inspection
4436521
NRC Walkdown items
07/22/2021
DOP 2300-M1/E1
Unit 3 HPCI System Checklist
Procedures
DOS 1500-M1
Unit 3 LPCI and Containment Cooling Valve Checklist
2 U2 Cable
Tunnel
Unit 2 Cable Tunnel East Elevation 502'
183 Cable Tunnel
FZ 8.2.4 Unit 3 Cable Tunnel West Elevation 502'
Fire Plans
2 U1CH
FZ 11.3 Unit 1 Crib House
DFPS 4114-13
Station Blackout Building Fire Equipment Inspection
Procedures
Fire Drill Performance
Corrective Action
Documents
4434425
Ground Water Intrusion in 2/3 Cable Tunnel
07/11/2021
Miscellaneous
OBE-21-02A
Dresden Operations LORT Training
295671
Butyl Rubber Cables Require Repairs
11/08/2019
4301941
DPIS 3-0261-34C
2/06/2019
28689
Work Order Required for Replacement of Unit 3 CCSW
Piping
03/23/2020
4333144
3-1501-2A
04/06/2020
4362775
D3M20: Grade 3 Stem Grease Found on 3-1501-28A
08/13/2020
Corrective Action
Documents
4395352
3A LPCI HX Tube Side Inlet Pressure Gauge Likely Clogged
01/12/2021
Corrective Action
Documents
Resulting from
Inspection
4434692
NRC Concern with Disposition of Rework to MSIV Air Piping
07/13/2021
Procedures
Procurement Engineering Process and Responsibilities
20503
EWP MM D3 16Y PM REP Ball Checks/Inspect Air
Hose/Replace VERSA Pilot
04/26/2021
4890312
D3 24M/RFL TS IST RV-Remove/Replace T-Rock Relief and
Pilot Assembly
05/24/2021
Work Orders
4946153
D3R25 Overhaul of XX-XX HCU
08/05/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
L1222 Switching
9/9/2021 Control
Room Risk
Screening
Risk Screening per OP-AA-107-F-01
09/09/2021
DFPS 4123-01
Unit 1 Diesel Fire Pump Operability
Procedures
DOP 4400-06
Operation of Unit 1 Screen Wash Pump
2610638
U3 HPCI Pump in IST Alert Range
01/11/2016
4090732
U3 HPCI Booster Pump Vibes
01/05/2018
4434751
DW Temps TE 3-5741-12A and TE 3-1053-B Above EQ
Limits
07/13/2021
4437971
Small Amount of Water Drained from Conduit on 2-0261-35A
07/30/2021
4438501
Flex Barge A Fuel Replacement
08/02/2021
4438968
Unit 2 SBO Secondary Vent Fan Did Not Start
08/04/2021
Corrective Action
Documents
4445418
Unit 3 HPCI Booster Pump Point 10A Vibrations
09/09/2021
Operability
Evaluations
2610411
U3 HPCI Outboard Booster Pump Bearing
01/10/2016
Procedures
Operability Determinations (CM-1)
05175915-01
Repair B CREVS VLV 2/3-3999-332 to 2/3-39248-3" Pipe
Leak
08/05/2021
Work Orders
5176215-05
OPS Perform PMT of HPCI Solenoid SV8 & SV12
09/14/2021
2610409
U3 HPCI Vibration
01/10/2016
2610411
U3 HPCI Outboard Booster Pump Bearing
01/10/2016
2610638
U3 HPCI Pump in IST Alert Range
01/11/2016
04090732
U3 HPCI Booster Pump Vibes
01/05/2018
Corrective Action
Documents
04445418
U3 HPCI Booster Pump Point 10A Vibrations
09/09/2021
Corrective Action
Documents
Resulting from
Inspection
04450385
U3 HPCI Vibration Data from Recent Surveillance
10/03/2021
DOS 1100-04
Standby Liquid Control System Quarterly/Comprehensive
Pump Test for the In-Service Testing Program
DOS 1400-05
Core Spray System Pump Operability and Quarterly IST Test
with Torus Available
Procedures
DOS 1500-02
Containment Cooling Service Water Pump Test and
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
In-Service Test
DOS 2300-03
High Pressure Coolant Injection System Operability and
Quarterly IST Verification Test
109
DOS 2300-03
High Pressure Coolant Injection System Operability and
Quarterly IST Verification Test
118
DOS 2300-07
High Pressure Coolant Injection Fast Initiation Test
DOS 2300-08
HPCI Pump Discharge Line Temperature Monitoring
DTP 09
Leak Detection Data Sheet
01873162
D3 QTR TS HPCI Pump Operability Test and IST
Surveillance
11/02/2015
Work Orders
5149543-01
OP D2 QTR TS CS PMP Test with Torus Avail for IST Data
Surveillance
07/27/2021
Eval No. 20-74
Emergency Action Levels for Dresden Station, EP-AA-1004,
Addendum 3
08/21/2020
Miscellaneous
Eval No. 20-86
Dresden Station Radiological Emergency Plan
09/19/2020
Miscellaneous
Dresden Station D3R26 RP/ALARA Refuel Outage Report
Fall 2020
Spring 2021
DR-03-20-00506
D3R26 Drywell Scaffold Installation/Removal Activities
DR-03-20-00520
D3R26 Drywell Snubbers
Radiation Work
Permits (RWPs)
DR-03-20-00901
U3R26 Reactor Disassembly/Reassembly Activities
04375666
Air Sampler D-03 Found Without Power
10/09/2021
Corrective Action
Documents
04409865
20 REMP Anomalies and ODCM Missed Samples
03/18/2021
Metrological Tower Inspection Report
04/19/2021
Miscellaneous
Dresden Nuclear Power Station 2020 Annual Radiological
Environmental Operating Report
05/06/2021
Corrective Action
Documents
Resulting from
Inspection
4446281
NRC Question
09/14/2021