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

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.

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) (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

71111.01

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

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

Documents

Resulting from

Inspection

CR 02359728

Revise Model Work Order for 2K237 Conduit Inspection

Revision 0

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

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

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

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

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-

1000-F01

Work Activity Risk Management Plan to Perform Power

Suppression Testing

Revision 3

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

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

71111.18

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

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

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

71152

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

71153

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