IR 05000237/2021001
| ML21103A432 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/13/2021 |
| From: | Kenneth Riemer NRC/RGN-III/DRP/B1 |
| To: | Rhoades D Exelon Generation Co, Exelon Nuclear |
| References | |
| IR 2021001 | |
| Download: ML21103A432 (15) | |
Text
April 13, 2021
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000237/2021001 AND 05000249/2021001
Dear Mr. Rhoades:
On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Dresden Nuclear Power Station, Units 2 and 3. On April 6, 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,
/RA/
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:
05000237/2021001 and 05000249/2021001
Enterprise Identifier: I-2021-001-0033
Licensee:
Exelon Generation Co., LLC
Facility:
Dresden Nuclear Power Station, Units 2 and 3
Location:
Morris, IL
Inspection Dates:
January 01, 2021 to March 31, 2021
Inspectors:
K. Barclay, Reactor Inspector
J. Corujo-Sandin, Senior Reactor Inspector
M. Domke, Resident Inspector
R. Elliott, Resident Inspector
A. Nguyen, Senior Resident Inspector
C. Phillips, Project Engineer
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 March 13, 2021, the unit was down powered to 77 percent to perform a quarterly control rod sequence exchange and routine testing. The unit was returned to rated thermal power on March 14, 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 March 6, 2021, the unit was down powered to 55 percent to perform a quarterly control rod sequence exchange, conduct control rod drive testing, and repair a main turbine control valve cable. The unit was returned to rated thermal power on March 7, 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 Disease 2019 (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; conducted plant status activities as described in IMC 2515, Appendix D, Plant Status; 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 portions 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 low temperatures from February 5, 2021 through February 12, 2021 for the following systems:
- Emergency diesel generators and station battery systems
- Ultimate heat sink and associated cooling water systems
- Safety-related secondary-side instrumentation
- Fire protection system
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 winter on January 26, 2021
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 3 turbine building closed cooling water (TBCCW) system on January 19, 2021
- (2) Unit 3 station blackout (SBO) diesel generator system on January 27, 2021
- (3) Unit 2 isolation condenser (IC) and makeup system on March 1, 2021
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) Emergency diesel generators the weeks of March 8 - 12 and March 22 - 26, 2021
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 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) 8.2.6.C, Unit 2/3 heat exchanger area, Elev. 534 on January 15, 2021
- (2) FZ 8.2.1.A, Unit 2 condensate pumps, Elev. 469 and FZ 8.2.2.A, Unit 2 CCSW pumps, Elev. 495 on January 15, 2021
- (3) Fire hose station compensatory measures due to Unit 2 turbine building fire header isolation on January 15, 2021
- (4) FZ 1.1.2.2, Unit 2 reactor ground floor, Elev. 517' on February 9, 2021
- (5) FZ 1.1.2.5.A, Unit 2 isolation condenser area, Elev. 589' on February 9, 2021
- (6) FZ 6.2, auxiliary electric equipment room (AEER), Elev. 517' on March 1, 2021
71111.06 - Flood Protection Measures
Cable Degradation (IP Section 03.02) (1 Sample)
The inspectors evaluated cable submergence protection in:
- (1) Manhole 8 after cables for Transformer 13 failed due to age-related degradation and submergence
71111.07A - Heat Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) 3A TBCCW heat exchanger
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 an out-of-the-box scenario and licensee evaluation of operator performance on February 23, 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) Unit 2 and Unit 3 high pressure cooling injection (HPCI) systems
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:
- (1) Secondary containment breach during fire protection system repair during the week of February 8, 2021
- (2) Planned elevated station risk during Unit 2 and Unit 3 HPCI maintenance windows during the weeks of February 22, 2021, and February 29, 2021
- (3) Emergent work for Unit 2 Digital Electro-Hydraulic Control (DEHC) pressure transmitter sheared sensing line A during the week of March 8, 2021
- (4) Planned elevated station risk during Unit 2 Division 1 ECCS work window during the week of March 29, 2021
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Unit 3 station blackout diesel generator air regulator failure on January 6, 2021
- (2) Unit 2 HPCI room temperature transmitter failure on February 1, 2021 (3)3B LPCI/CCSW heat exchanger tube side pressure low on February 24, 2021
- (4) Unit 2 HPCI gland seal condenser level high control room alarm on February 23, 2021
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) Unit 2 DEHC modification to input temporary point into pressure controller for failed 2
'A' throttle pressure transmitter on March 12, 2021
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) DOS 0300-01, Unit 3 control rod exercising after rod select matrix replacement on January 23, 2021
- (2) DOS 6620-07, Unit 2 station blackout diesel generator surveillance test after maintenance window on January 28, 2021
- (3) Unit 3 HPCI comprehensive pump test and leakage checks after maintenance window per Work Order (WO) 4894499
- (4) Unit 2 emergency diesel generator post-maintenance run and operability surveillance after maintenance window per WO 5079087 and 1823439
- (5) Unit 2 HPCI comprehensive pump test and leakage checks after maintenance window per WO 4903464
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) DIS 0700-21, Unit 2 local power range monitor alarm calibration on February 8, 2021
- (2) DOS 1500-02, Unit 2 containment cooling service water pump test and In-service test on March 17, 2021
- (3) DOS 6600-01, Unit 2/3 emergency diesel generator monthly test for In-service testing (IST) on March 24, 2021
Inservice Testing (IP Section 03.01) (1 Sample)
- (1) DOS 1100-04, Unit 3 'A' standby liquid control quarterly/comprehensive pump test for In-service testing (IST) on February 4, 2021
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)
- (1) Focused area drill in technical support center (TSC), first quarter
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 03.01)===
- (1) Unit 2 (January 1, 2020 - December 31, 2020)
- (2) Unit 3 (January 1, 2020 - December 31, 2020)
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02) (2 Samples)
- (1) Unit 2 (January 1, 2020 - December 31, 2020)
- (2) Unit 3 (January 1, 2020 - December 31, 2020)
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 03.03) (2 Samples)
- (1) Unit 2 (January 1, 2020 - December 31, 2020)
- (2) Unit 3 (January 1, 2020 - December 31, 2020)
INSPECTION RESULTS
No findings were identified.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On April 6, 2021, the inspectors presented the integrated inspection results to Mr. P. Karaba, Site Vice President, and other members of the licensee staff.
THIRD PARTY REVIEWS
The inspectors reviewed the Institute on Nuclear Power Operations report that was issued during the inspection period.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
4400717
'A' FLEX Building Heater not Working
2/06/2021
4400777
Reserve Auxiliary Transformer (TR-32) Trouble
2/07/2021
4400786
Unit 2 Stator Water Loop Seal Vent Potentially Blocked
2/07/2021
4400797
Main Transformer 3 Trouble
2/07/2021
4400829
Unit 3 Stator Water Drain Lower Sight Glass not Full of
Water
2/06/2021
Procedures
DOS 0010-22
Preparation for Cold Weather Operations for Unit 2
DOS 0010-25
Preparation for Cold Weather Operations for Unit 3
OP-DR-108-111-
1004
Cold Weather Strategy
Corrective Action
Documents
4398456
U3 SBO Isolimiter Noise
01/28/2021
4400510
Elevated Boron Additive Level in Engine Oil
2/05/2021
4410280
2-6600, Unit 2 EDG Turbo Oil Circulating Pump Leak
03/20/2021
Procedures
DOP 1300-E1/M1
Unit 2 Isolation Condenser System Checklist
DOP 3800-M1
Unit 3 Turbine Building Closed Cooling Water System
Checklist
DOP 6600-E1
Unit 3 Standby Diesel Generator
DOP 6600-E1
Unit 2 Standby Diesel Generator
DOP 6600-E2
Unit 2/3 Standby Diesel Generator
DOP 6600-M1
Unit 2 Standby Diesel Generator
DOP 6600-M1
Unit 3 Standby Diesel Generator Checklist
DOP 6600-M2
Unit 2/3 Emergency Diesel Generator Checklist
DOP 6620-16
SBO DG 2(3) Preparation for Standby Readiness
DOP 6620-E2
Unit 3 Station Blackout Electrical Checklist
Corrective Action
Documents
4395860
Unit 2 Low Pressure Heater Bay Fire Piping Leak Degrading
01/14/2021
4395944
Leak on 2A Control Rod Drive Pump from Fire Header Leak
01/14/2021
Corrective Action
Documents
Resulting from
Inspection
4396264
NRC Plant Walkdown
01/15/2021
Fire Plans
FZ 1.1.2.2
Unit 2 Reactor Ground Floor, Elev. 517'
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
FZ 1.1.2.5.A
Unit 2 Isolation Condenser Area, Elev. 589'
FZ 6.2
Unit 2/3 Computer Room & Auxiliary Electrical Room
Elevation 517'
FZ 8.2.1.A
Unit 2 Condensate Pumps, Elev. 469 and FZ 8.2.2.A, Unit 2
CCSW Pumps, Elev. 495
and 04
FZ 8.2.6.C
Unit 2/3 Heat Exchanger Area, Elev. 534
Miscellaneous
Logs
Fire Hose Station Compensatory Measures Due to Unit 2
Turbine Building Fire Header Isolation
01/15/2021
Corrective Action
Documents
4389709
Smoke Reported from Manhole 8
2/11/2020
4396905
Bus 14 and Bus 15 Tie ACB Continuously Cycling Open and
Closed
01/20/2021
Work Orders
5107462
Repair Damaged Faulted Cables in Manhole 8
01/15/2021
Corrective Action
Documents
4397248
Abbreviated Maintenance for TBCCW Heat Exchanger
Year PM
01/21/2021
4397298
3A TBCCW Heat Exchanger Endbell Leak
01/21/2021
4397520
3A TBCCW Heat Exchanger Eddy Current Test Results
01/21/2021
Engineering
Evaluations
418217
Evaluation to Use Replacement Channel Cover Without
"Plasti-cor" Coating
Work Orders
1818634
3A TBCCW Heat Exchanger Eddy Current Test and
Clean/Inspect
01/21/2021
71111.11Q Miscellaneous
Out-of-the-Box Evaluation
2/23/2021
Corrective Action
Documents
27061
Leak from Unit 2 HPCI Main Pump
03/06/2019
4317672
HPCI Work Order Instructions Altered Outside of Process
2/13/2020
4350983
DTP 09: Leak on HPCI Main Pump Seal
06/17/2020
4406431
DTP 09: Leak on Unit 2 HPCI Main Pump Seal
03/03/2021
4406436
Unit 2 HPCI Turbine Small Oil Leak
03/03/2021
Engineering
Changes
397957
Replace Unit 3 HPCI Signal Converter and Flow Indicating
Controller
Miscellaneous
High Pressure Injection Health Group Report and Action
Plan
2/05/2021
Work Orders
4896331
Leak from Unit 2 Main HPCI Pump
03/05/2020
5115257
Replace HPCI Pump (Main) South Facing Seal
03/04/2021
Corrective Action
4405642
Water Near 2-2202-19B Rack
03/01/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Documents
4407517
Unit 2 DEHC Throttle Pressure Transmitter Failed
03/09/2021
Corrective Action
Documents
Resulting from
Inspection
4412434
2/3-4699-189 Tank A2 Drain Valve Has Air Leak
03/29/2021
4412443
NRC Plant Walkdown
03/29/2021
Engineering
Evaluations
445515
Evaluation of Tophat Needed to Support Maintenance of the
Secondary Containment During Replacement of Line
2-4101-6"
Procedures
DAP 07-44
Control of Temporary Openings in Secondary Containment
During Performance of Work Packages, Surveillances, or
Other Procedures
Protected Equipment Program
OP-DR-201-012-
1001
Dresden On-Line Fire Risk Management
On-line Work Control Process
On-Line Risk Management and Assessment
Corrective Action
Documents
2138
Unexpected HPCI Alarm (Gland Seal Condenser)
2/20/2003
4388991
3B LPCI Heat Exchanger Tube Side Pressure Reading 0#
2/09/2020
4394322
Unit 3 SBO Engine B Air Regulator Failed
01/06/2021
4399538
Found Temperature Transmitter 22-5703-27A Out of
Tolerance and Unable to Calibrate
2/01/2021
4404311
Unexpected Main Control Room Alarm: HPCI Gland Seal
Condenser Level High
2/23/2021
4404340
3B LPCI HX Tube Side Inlet Pressure Reading 0
2/24/2021
848148
HPCI Gland Seal Condenser Level High Alarm
11/21/2008
Drawings
Schematic Diagram Control Room Annunciator Panel 923-5
E
Engineering
Evaluations
2944
Containment Cooling Service Water (CCSW) System Water
Hammer Loss of Keep Fill Analysis
373115
Evaluation of High-Level Alarm in the HPCI Gland Seal
Condenser
11/21/2008
Procedures
DAN 902(3)-3 H-
HPCI Gland Seal Condenser Hotwell Level HI/LO
DAN 923-5 H-1
Unit 2 HPCI Pump Area Temperature High
Engineering
633771
Temporary Force Unit 2 DEHC Logic Point to Inhibit
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Evaluations
Automatic Control Transfer from Dome to Throttle Control
Corrective Action
Documents
4398523
Unit 2 SBO Surveillance Non-Acceptance Criteria Data out
of Nominal Band
01/28/2021
4398770
2B SBO Engine Duplex Fuel Strainer Differential Pressure
High, Recommend Cleaning
01/28/2021
4398772
2A SBO Engine Duplex Fuel Strainer Differential Pressure
High, Recommend Cleaning
01/28/2021
4398775
Unit 2 SBO Engine A Coolant at Low End of Band
01/28/2021
4404311
Unexpected Main Control Room Alarm: HPCI Gland Seal
Condenser Level High
2/23/2021
4404323
Unit 3 HPCI Room Cooler
2/23/2021
4406433
DTP 09: Unit 2 HPCI Pump Leak from Casing Bolt
03/03/2021
4406434
Unit 2 HPCI Cooling Water PCV Oscillating
03/03/2021
4407817
Unit 2 Diesel Overload Alarm will not Reset
03/10/2021
4407968
Unexpected Alarm: Unit 3 125V DC Ground During Unit 2
EDG Run
03/10/2021
Engineering
Evaluations
373115
Evaluation of High-Level Alarm in the HPCI Gland Seal
Condenser
11/21/2008
Procedures
DOS 0300-01
Control Rod Exercise
Work Orders
23439
Unit 2 Diesel Generator Operability Run
03/10/2021
4598543-02,
4598541-02, and
4598544-02
PMT - Rebuild/Replace Air Start Regulating Valves on SBO
Diesel
01/27/2021
4894499
Unit 3 HPCI Pump Comprehensive Operability Test and IST
Surveillance
2/24/2021
4903464
HPCI Pump Comprehensive Operability Test and IST
Surveillance
03/03/2021
5079087
Unit 2 Diesel Generator Fast Start Operability Surveillance
03/10/2021
5090298
Unit 2 Station Blackout Diesel Generator Surveillance Test
01/28/2021
857684-15
Replace the Unit 3 Rod Select Matrix Module
01/21/2021
Corrective Action
Documents
4381265
LPRM 24-09C Downscale
10/31/2020
4401381
Found LPRM Alarm Calibration out of Tolerance
2/08/2021
4401382
Found LPRM Alarm Calibration out of Tolerance
2/09/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
4401384
Found LPRM Alarm Calibration out of Tolerance
2/08/2021
Procedures
DIS 0700-21
Local Power Range Monitor Alarm Calibration
DOS 1100-04
Standby Liquid Control System Quarterly/Comprehensive
Pump Test for the Inservice Testing (IST) Program
DOS 1500-02
Containment Cooling Service Water Pump Test and
Inservice Test
DOS 6600-01
Diesel Generator Surveillance Test
145
Miscellaneous
Focused Area Drill for Technical Support Center (TSC), First
Quarter 2021
71151
Miscellaneous
Operator Logs
01/01/2020 -
2/31/2020