IR 05000331/2020002

Integrated Inspection Report 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 05000331/2020002

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: DPR-49 Report Number: 05000331/2020002 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 Enclosure

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.

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,

71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, &

Transportation

Waste Characterization and Classification (IP Section 03.03)

(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 71152 Failures 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 Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action CR 0230683 Initiate WO to Relocate Gasoline/Diesel Storage Tanks Revision 0

Documents

Procedures AOP 902 Flood Revision 62

AOP 903 Severe Weather Revision 61

71111.04 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

71111.05 Fire Plans PFP-OE-757 Pre-Fire Plan OAG-PA East El. 757 Revision 1

PFP-OS-757 Pre-Fire Plan OAG-PA South El. 757 Revision 1

PFP-PH-757 Pre-Fire Plan Pump House Revision 3

PFP-RB-812 Pre-Fire Plans Reactor Building Elevation 812 Revision 7

PFP-RB-833 Pre-Fire Plan Reactor Building Elevation 833 Revision 4

PFP-RB-855 Pre-Fire Plans Reactor Building Elevation 855 Revision 5

71111.06 Corrective Action CR 02359728 Revise Model Work Order for 2K237 Conduit Inspection Revision 0

Documents

Resulting from

Inspection

Work Orders WO 40622627 Inspect Conduit 2K237 and Dewater as Necessary 06/08/2020

71111.11Q Miscellaneous ESG 2020B-O1E Evaluated Scenario Revision 0

Procedures NF-AA-100-1001 Failed Fuel Action Plan Revision 5

STP NS262101 Power Suppression Testing Revision 14

71111.12 Corrective Action CR 02355373 RCIC Steam Leak Revision 0

Documents

Drawings FSK-08065 Instr. Root Valve Detail for PT-2403, PI-2402, PP2456A 7 B Revision 8

R.C.I.C. Room

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 WO 40660977 1P229B RHR Pump Suction Relief 05/18/2020

WO 40719539-01 EBB015: Remove Spool Piece and Install New Gaskets 05/06/2020

71111.13 Corrective Action CR 02352828 Step Change in Off Gas Pretreat Rad Levels Revision 0

Documents CR 02352982 Develop Work Plan for Power Suppression Testing Revision 0

Inspection Type Designation Description or Title Revision or

Procedure Date

CR 02360380 'B' River Water Supply Building Exhaust Dampers Found Revision 0

Closed

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 Power Suppression Testing April 2020 04/18/2020

Management

Plan

SD 264 Reactor Recirculation System Revision 13

Procedures NF-AA-100-1001 Failed Fuel Action Plan Revision 8

NS262101 Power Suppression Testing Revision 3

OI 264 Reactor Recirculation System Revision 143

WM-AA-100- Work Activity Risk Management Plan to Perform Power Revision 3

1000-F01 Suppression Testing

Work Orders WO 40672647 V20-0006: Dis-Assemble and Inspect 04/27/2020

WO 40705991 Packing Leak on MO 2512 04/21/2020

WO 40729042 'B' River Water Supply Building Exhaust Dampers 05/19/2020

71111.15 Corrective Action CR 02351714 1P117C RWS Pump Motor is Above ASME Vibration Limit Revision 0

Documents 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 Revision 0

Temperature at Baseline Plus 30°F

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, Revision 48

Breathing Air Building Compressor Diagram

Procedures AOP 683 Abnormal Safety Relief Valve Operation Revision 22

Inspection Type Designation Description or Title Revision or

Procedure Date

MA-AA-100 1011- Troubleshooting Revision 7

F01

STP 3.7.9-02B B CB/SBGTS Instrument Air Compressor Functional Test Revision 12

and Check Valve Testing

STP 3.7.9-03 CB/SBGTS Instrument Air Compressors System Leakage Revision 8

and Capacity Test

STP NS750001 Service Discharge Test of Batteries 1D5 and 1D6 Revision 19

71111.18 Drawings P.& I.D. BECH- Radwaste Sump System Revision 39

M137<1>

Miscellaneous RTM-01920 Drywell Floor Drain Sump Sample Rig 05/07/2020

Procedures OI 920 Drywell Sump System Revision 48

71111.19 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 WO 40660977 1P229B RHR Pump Suction Relief Valve 05/18/2020

WO 40680427 Air Compressor 1K-4/1K-3 ESS/WW Inlet Check Valve 06/24/2020

WO 40705991 Packing Leak on MO 2512 04/21/2020

WO 40729042 'B' River Water Supply Building Exhaust Dampers 06/19/2020

71111.22 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 WO 40677758 RCIC System Operability Test 06/02/2020

WO 40677765 'A' Core Spray Operability Test 06/01/2020

71114.06 Miscellaneous ESG 2020B-OE Evaluated Scenario Revision 0

71124.08 Corrective Action 02291677 Cannot Meet Procedural Requirements for Dewatering 11/20/2018

Documents Verification

Miscellaneous 17-009-R 10 CFR 61 Compliance Data Technical Basis for DAEC Dry 11/15/2017

Active Waste

18-001-R 10 CFR 61 Compliance Data Technical Basis for DAEC 12/18/2018

Condensate Resin

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 02/26/2019

Inspection Type Designation Description or Title Revision or

Procedure Date

71151 Miscellaneous NG-001L, NRC PI Review and Approval, for Second Quarter 2019 Through Revision 5

Data Calculation First Quarter 2020

71152 Corrective Action CR 02075615 Wet Spot on Northeast Corner of C Well House Revision 0

Documents CR 02104154 Well Water Return Line Leaking Revision 0

CR 02169071 Small Leak Coming from Overhead Near 1st Floor RB Revision 0

Elevator

CR 02196376 Flange on Well Water Temp Mod Leaking at Threaded Revision 0

Connection

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 Underground Well Water Piping Leak in Parking Lot #6 01/08/2019

Equipment

Failure

Investigation

71153 Corrective Action CR 02359667 Observed Reduction in 'B' Recirculation Pump Speed Revision 0

Documents

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

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