IR 05000331/2020002
| ML20217L486 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 08/04/2020 |
| From: | April Nguyen NRC/RGN-III/DRP/B2 |
| To: | Dean Curtland NextEra Energy Duane Arnold |
| References | |
| IR 2020002 | |
| Download: ML20217L486 (15) | |
Text
August 4, 2020
SUBJECT:
DUANE ARNOLD ENERGY CENTER - INTEGRATED INSPECTION REPORT
Dear Mr. Curtland:
On June 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Duane Arnold Energy Center. On July 9, 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/
April M. Nguyen, Acting Chief Branch 2 Division of Reactor Projects
Docket No. 05000331 License No. DPR-49
Enclosure:
As stated
Inspection Report
Docket Number:
05000331
License Number:
Report Number:
Enterprise Identifier: I-2020-002-0029
Licensee:
NextEra Energy Duane Arnold, LLC
Facility:
Duane Arnold Energy Center
Location:
Palo, IA
Inspection Dates:
April 01, 2020 to June 30, 2020
Inspectors:
V. Myers, Senior Health Physicist
C. Norton, Senior Resident Inspector
Approved By:
April M. Nguyen, Acting Branch Chief
Branch 2
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Duane Arnold Energy Center, 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 rated thermal power. On April 14, 2020, the licensee detected a fuel element failure. On April 20, 2020, the licensee lowered power to 60 percent of rated thermal power to perform full core power suppression testing. The licensee gradually increased reactor power to achieve 100 percent of rated thermal power on April 27, 2020. On May 22, 2020, the licensee isolated the 'A' loop of primary containment cooling to stop a well water leak inside primary containment. Reactor power was lowered to 70 percent rated thermal power to maintain primary containment temperature below the technical specification limit.
Limited by primary containment temperature, reactor power remained between 65 percent and 75 percent rated thermal power until June 30, 2020. On June 30, 2020 the licensee recovered the 'A' primary containment cooling loop and began increasing thermal power. The unit ended the inspection period at 83 percent rated thermal 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.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated licensee actions for heavy precipitation, rainfall exceeding 0.5 inches, on May 17, 2020.
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 for second river flood crest on June 29, 2020.
External Flooding Sample (IP Section 03.03) (1 Sample)
- (1) The inspectors evaluated 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 June 12, 2020.
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) Off gas system pretreat line up for power suppression testing on April 21, 2020.
- (2) Well water system while aligned to repair system leak in the 'C' well water pump discharge line on June 16, 2020.
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configurations during a complete walkdown of the systems and components for transfer of spent fuel from the fuel pool to the interim spent fuel storage installation on May 29, 2020.
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 4A and B (Reactor Building Elevation 812') on April 9, 2020
- (2) Fire Zone 6A (Reactor Building Elevation 855') on April 9, 2020
- (3) Fire Zone 5C (Reactor Building Elevation 833') on April 9, 2020
- (4) Fire Zone OAG-PA East (Outside) on April 21, 2020
- (5) Fire Zone OAG-PA South (Outside) on April 21, 2020
- (6) Fire Zone 16A and 16B (Pump House) on April 21, 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) Conduit 2K237 on June 12, 2020
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 power suppression testing on April 21, 2020.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator requalification training and activities on May 5, 2020.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
- (1) Reactor core isolation cooling (RCIC) system (2)
'B' emergency diesel generator (EDG)
(3)
'B' residual heat removal (RHR) system
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (7 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) Emergent work to suppress fuel leak on April 22, 2020
- (2) Elevated risk activity to adjust the packing on MO 2512, RCIC inlet valve, on April 22, 2020
- (3) Elevated risk associated with 'B' RHR service water (SW) pit and stilling basin inspection on April 28, 2020
- (4) Elevated risk associated with the disassembly and inspection of the 'A' RHR pump discharge bypass line check valve on June 2, 2020
- (5) Emergent work and elevated risk associated with 'B' recirculation pump motor generator (MG) set scoop tube drift on June 16, 2020
- (6) Emergent work associated with 'B' river water supply building exhaust dampers failing closed on June 21, 2020
- (7) Emergent work associated with underground leak on the 'C' well water discharge header on June 30, 2020
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (8 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) CR 02351714, 'C' river water supply pump motor is above ASME vibration limit on April 8, 2020
- (2) CR 02351755, C containment iodine channel not responding in cabinet 219 A on April 8, 2020
- (3) CR 02356117, abnormal rise in torus level since drywell leak on May 11, 2020
- (4) CR 02355373, steam leak on reactor core isolation cooling (RCIC) system steam supply on June 3, 2020
- (5) CR 02359227, Pressure Safety Valve, PSV-4407, tailpipe temperature at baseline plus 30 degrees F on June 9, 2020
- (6) CR 023593231, 'B' control building/standby gas treatment system instrument air compressor took longer than expected to recharge flask after performing functional test and check valve testing on June 10, 2020
- (7) CR 02360296, Procedural steps not completed as required during 1D6 battery discharge test on June 19, 2020
- (8) CR 02360380, 'B river water system building exhaust dampers found closed on June 19, 2020
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) Recurring temporary modification to install drywell floor drain sample rig on May 7, 2020.
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (6 Samples)
The inspectors evaluated the following post maintenance test activities to verify system operability and functionality:
- (1) Valve stroke timing following packing adjustment on MO 2512, reactor core isolation cooling system (RCIC) isolation valve on April 22, 2020
- (2) Diesel system walkdown for leaks during run following maintenance activities on the
'B' emergency diesel generator on May 12, 2020
- (3) System walkdown to verify no leakage following the repair of a steam leak upstream of the RCIC trip throttle valve on May 13, 2020
- (4) Verification of no flange leakage following replacement of the 'B' residual heat removal pump suction relief valve on May 19, 2020
- (5) Verification of proper damper operation following repair of 'B' river water supply building exhaust dampers on June 21, 2020
- (6) Verification of no leakage following disassembly and inspection of the 'B' standby gas treatment/control building instrument air compressor emergency service water/well water inlet check valve on June 24, 2020
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) Post accident sample system leakage inspection on June 23, 2020.
Inservice Testing (IP Section 03.01) (3 Samples)
- (1) RCIC system operability test on June 5, 2020 (2)
'B' EDG operability test on May 13, 2020 (3)
'A' core spray (CS) system operability test on June 1, 2020
71114.06 - Drill Evaluation
Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)
The inspectors evaluated:
- (1) Licensed operator retraining evaluated scenario emergency action level classification on May 12,
RADIATION SAFETY
71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, &
Transportation
Waste Characterization and Classification (IP Section 03.03) (2 Samples)
- (1) The inspectors evaluated the licensees characterization and classification of radioactive waste shipment 18-14.
- (2) The inspectors evaluated the licensees characterization and classification of radioactive waste shipment 19-01.
Shipping Records (IP Section 03.05) (3 Samples)
The inspectors evaluated the following non-excepted radioactive material shipments through a record review:
- (1) Shipment Number 18-14; UN3321, Radioactive Materials, Low Specific Activity (LSA-II)
- (2) Shipment Number 18-33; UN2915, Radioactive Materials, Type A Package
- (3) Shipment Number 19-01; UN3321, Radioactive Materials, Low Specific Activity (LSA-II)
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
BI02: RCS Leak Rate Sample (IP Section 02.11)===
- (1) Unit 1 (April 1, 2019 through March 31, 2020)
OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)
- (1) Unit 1 (April 1, 2019 through March 31, 2020)
71152 - Problem Identification and Resolution
Semiannual Trend Review (IP Section 02.02) (1 Sample)
- (1) The inspectors reviewed the licensees corrective action program for potential adverse trends in 'C' well water pump discharge underground leaks that might be indicative of a more significant safety issue.
71153 - Followup of Events and Notices of Enforcement Discretion Personnel Performance (IP Section 03.03)
- (1) The inspectors evaluated plant personnel performance during isolation of the 'A' loop of drywell cooling to stop an increase in drywell unidentified leakage on May 22, 2020.
- (2) The inspectors evaluated operator performance during an unplanned reactivity change caused by the 'B' recirculation pump MG set scoop tube drifting on June 16,
INSPECTION RESULTS
Observation: Semi Annual Trend-'C' Well Water Pump Discharge Line Repeated Failures 71152 Well water is a non-safety related system, consisting of four separate well pumps that provide the site with water for multiple uses. Well water provides an alternate source of water to the fire protection system. It is an emergency source of water for reactor injection.
On June 9, 2020, the licensee identified a 100-gallon per minute leak in the C well water underground discharge header in the security owner-controlled area adjacent to parking lot number 6. The licensee documented five previous leaks in the C well underground piping in parking lot number 6. These occurred in March and May 2000, February and September 2009, and January 2019. Previous piping failure evaluations and subsequent soil testing found the soil in parking lot number 6 corrosive, the result of the plant construction concrete batch plant located in the area.
The licensee efficiently repaired the historical leaks in a manner commensurate with the safety significance. In addition, the licensee had authorized an engineering change to pull a flexible liner through the pipe in the summer of 2018. The modification, however, was cancelled when the 2020 plant decommissioning was announced in early 2018. The liner would have prevented the 2019 and 2020 leaks.
The inspectors determined the decision to cancel the modification was reasonable. System redundancies ensured the well water function was adequately maintained during periods in 2019 and 2020 when the C well was unavailable. The sub system unavailability would have likely been longer for the liner installation than for the cumulative time to repair the 2019 and 2020 leaks.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On July 9, 2020, the inspectors presented the integrated inspection results to Mr. D. Curtland, Director of Site Operations, and other members of the licensee staff.
- On June 26, 2020, the inspectors presented the radiation protection inspection results to Mr. D. Curtland, Director of Site Operations, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
CR 0230683
Initiate WO to Relocate Gasoline/Diesel Storage Tanks
Revision 0
Procedures
AOP 902
Flood
Revision 62
AOP 903
Severe Weather
Revision 61
Drawings
BECH-144<2>
Well Water Cooling System
Revision 40
Bech-M 141
Off Gas System
Revision 76
Miscellaneous
Video
Time Lapse Video of ISFSI Fuel Transfer Process
05/29/2020
Fire Plans
Pre-Fire Plan OAG-PA East El. 757
Revision 1
Pre-Fire Plan OAG-PA South El. 757
Revision 1
Pre-Fire Plan Pump House
Revision 3
Pre-Fire Plans Reactor Building Elevation 812
Revision 7
Pre-Fire Plan Reactor Building Elevation 833
Revision 4
Pre-Fire Plans Reactor Building Elevation 855
Revision 5
Corrective Action
Documents
Resulting from
Inspection
CR 02359728
Revise Model Work Order for 2K237 Conduit Inspection
Revision 0
Work Orders
Inspect Conduit 2K237 and Dewater as Necessary
06/08/2020
71111.11Q Miscellaneous
ESG 2020B-O1E
Evaluated Scenario
Revision 0
Procedures
Failed Fuel Action Plan
Revision 5
STP NS262101
Power Suppression Testing
Revision 14
Corrective Action
Documents
CR 02355373
RCIC Steam Leak
Revision 0
Drawings
FSK-08065
Instr. Root Valve Detail for PT-2403, PI-2402, PP2456A 7 B
R.C.I.C. Room
Revision 8
ISO-EBB-015-01
R.C.I.C. Steam Inlet
Revision 2
Procedures
STP 3.8.1-06B
B Standby Diesel Generator Operability Test (Fast Start)
Revision 27
Work Orders
1P229B RHR Pump Suction Relief
05/18/2020
EBB015: Remove Spool Piece and Install New Gaskets
05/06/2020
Corrective Action
Documents
CR 02352828
Step Change in Off Gas Pretreat Rad Levels
Revision 0
CR 02352982
Develop Work Plan for Power Suppression Testing
Revision 0
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR 02360380
'B' River Water Supply Building Exhaust Dampers Found
Closed
Revision 0
Drawings
BECH-C101
Grading Drainage/Utilities Area C
Revision 49
BECH-C117
Grading Drainage/Utilities Area B
Revision 8
BECH-C119
Grading Drainage/Utilities Area E
Revision 10
BECH-C122
Grading Drainage/Utilities Area H
Revision 20
BECH-C123
Grading Drainage/Utilities Area J
Revision 18
BECH-C127
Grading Drainage/Utilities Area N
Revision 70
Miscellaneous
Reactivity
Management
Plan
Power Suppression Testing April 2020
04/18/2020
SD 264
Reactor Recirculation System
Revision 13
Procedures
Failed Fuel Action Plan
Revision 8
NS262101
Power Suppression Testing
Revision 3
OI 264
Reactor Recirculation System
Revision 143
WM-AA-100-
1000-F01
Work Activity Risk Management Plan to Perform Power
Suppression Testing
Revision 3
Work Orders
V20-0006: Dis-Assemble and Inspect
04/27/2020
Packing Leak on MO 2512
04/21/2020
'B' River Water Supply Building Exhaust Dampers
05/19/2020
Corrective Action
Documents
CR 02351714
1P117C RWS Pump Motor is Above ASME Vibration Limit
Revision 0
CR 02351755
1C219A Iodine Channel not Responding
Revision 0
CR 02355373
Steam Leak from Flanged Connection Adjacent V23-0057
Revision 0
CR 02356177
Abnormal Rise in Torus Level Since Drywell Leak
Revision 0
CR 02359021
Temperature Approaching AOP Entry Point
Revision 0
CR 02359227
PSV [Pressure Relief or Safety Valve]- 4407, Tailpipe
Temperature at Baseline Plus 30°F
Revision 0
CR 02360296
1D6 Battery Discharge
Revision 0
CR 02360380
B River Water Exhaust Dampers Found Closed
Revision 0
Drawings
BECH-M173
P&ID & Air Flow Diagram SFU for Control Building
Revision 64
BECH-M177
P&I
- D. Intake Structure, TSC, Compressor Building, H&V,
Breathing Air Building Compressor Diagram
Revision 48
Procedures
AOP 683
Abnormal Safety Relief Valve Operation
Revision 22
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
MA-AA-100 1011-
F01
Troubleshooting
Revision 7
STP 3.7.9-02B
B CB/SBGTS Instrument Air Compressor Functional Test
and Check Valve Testing
Revision 12
STP 3.7.9-03
CB/SBGTS Instrument Air Compressors System Leakage
and Capacity Test
Revision 8
STP NS750001
Service Discharge Test of Batteries 1D5 and 1D6
Revision 19
Drawings
P.& I.D. BECH-
M137<1>
Radwaste Sump System
Revision 39
Miscellaneous
RTM-01920
Drywell Floor Drain Sump Sample Rig
05/07/2020
Procedures
OI 920
Drywell Sump System
Revision 48
Procedures
OI 324
Standby Diesel Generator
Revision 127
STP 3.7.9-01B
CB/SBGTS Instrument Air Compressor 1K-4 Functional Test
Revision 11
Work Orders
1P229B RHR Pump Suction Relief Valve
05/18/2020
Air Compressor 1K-4/1K-3 ESS/WW Inlet Check Valve
06/24/2020
Packing Leak on MO 2512
04/21/2020
'B' River Water Supply Building Exhaust Dampers
06/19/2020
Procedures
STP 3.5.1-01
'A' Core Spray System Operability Test
Revision 26
STP 3.5.3-02
RCIC System Operability Test
Revision 56
STP 3.8.1-06B
B Standby Diesel Generator Operability Test (Fast Start)
Revision 27
STP NS 770204
Post-Accident Sample System Leakage Inspection
Revision 22
Work Orders
RCIC System Operability Test
06/02/2020
'A' Core Spray Operability Test
06/01/2020
Miscellaneous
ESG 2020B-OE
Evaluated Scenario
Revision 0
Corrective Action
Documents
291677
Cannot Meet Procedural Requirements for Dewatering
Verification
11/20/2018
Miscellaneous
17-009-R
CFR 61 Compliance Data Technical Basis for DAEC Dry
Active Waste
11/15/2017
18-001-R
CFR 61 Compliance Data Technical Basis for DAEC
Condensate Resin
2/18/2018
Shipping Records 18-14
Dry Active Waste Shipment LSA-II
06/04/2018
18-33
Vessel Scrapings Shipment Type A Package
09/18/2018
19-01
Condensate Resin Shipment LSA-II
2/26/2019
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71151
Miscellaneous
NG-001L, NRC PI
Data Calculation
Review and Approval, for Second Quarter 2019 Through
First Quarter 2020
Revision 5
Corrective Action
Documents
CR 02075615
Wet Spot on Northeast Corner of C Well House
Revision 0
CR 02104154
Well Water Return Line Leaking
Revision 0
CR 02169071
Small Leak Coming from Overhead Near 1st Floor RB
Elevator
Revision 0
CR 02196376
Flange on Well Water Temp Mod Leaking at Threaded
Connection
Revision 0
CR 02213054
Leak from V44-436 IT-448 Back Pressure/Anti-Siphon Valve
Revision 0
CR 02278425
Control Room Toilet Flush Valve Leakage
Revision 0
CR 02295487
Leak on Well Water Chemical Injection Line
Revision 0
CR 02297131
Leak from Underground Piping on the Discharge of 1P058C
Revision 0
CR 02355740
High Drywell Floor Drain Leakage
Revision 0
CR 02359365
C Well Discharge Header Has About 100 GPM Leak
Revision 0
ER 2297131
Equipment
Failure
Investigation
Underground Well Water Piping Leak in Parking Lot #6
01/08/2019
Corrective Action
Documents
CR 02359667
Observed Reduction in 'B' Recirculation Pump Speed
Revision 0
Procedures
AOP 255.2
Power/Reactivity Abnormal Change
Revision 49
IPOI 3
Power Operations (35%-100% Rated Thermal Power)
Revision 160
OI 760
Drywell Cooling System
Revision 30