IR 05000331/2019002

Integrated Inspection Report 05000331/2019002

ML19214A109
Person / Time
Site:	Duane Arnold
Issue date:	08/01/2019
From:	Billy Dickson NRC/RGN-III
To:	Dean Curtland Nextera Energy
References
IR 2019002
Download: ML19214A109 (26)

Text

August 1, 2019

SUBJECT:

DUANE ARNOLD ENERGY CENTERINTEGRATED INSPECTION REPORT 05000331/2019002

Dear Mr. Curtland:

On June 30, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Duane Arnold Energy Center. On July 11, 2019, 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.

Two findings of very low safety significance (Green) are documented in this report. One of these findings involved violations of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.

If you contest the violations or significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:

Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at Duane Arnold.

If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; and the NRC Resident Inspector at Duane Arnold. 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 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Billy Dickson, 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:

05000331/2019002

Licensee:

NextEra Energy Duane Arnold, LLC

Facility:

Duane Arnold Energy Center

Location:

Palo, Iowa

Inspection Dates:

April 01, 2019 to June 30, 2019

Inspectors:

B. Bartlett, Project Engineer

J. Beavers, Senior Resident Inspector

G. Hansen, Sr. Emergency Preparedness Inspector

D. Johnson, Sr. Emergency Preparedness Specialist

V. Myers, Senior Health Physicist

C. Norton, Senior Resident Inspector

T. Ospino, Reactor Engineer

J. Rutkowski, Project Engineer

Approved By:

Billy Dickson, 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

Failure to Notify Radiation Protection of Change In Work Scope Cornerstone Significance Cross-Cutting Aspect Report Section Occupational Radiation Safety Green NCV 05000331/2019002-01 Open/Closed

[H.4] - Teamwork 71124.01 The inspectors reviewed a self-revealed finding of very low safety significance (Green) and an associated Non-Cited Violation (NCV) of TS 5.4.1, Procedures, when the licensee failed to implement contamination control procedures when machining a contaminated main steam isolation valve disk without radiation protection knowledge.

Failure to Manage Outage Risk Activities Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green FIN 05000331/2019002-02 Open/Closed

[H.5] - Work Management 71153 A self-revealed finding of very low safety significance (i.e., Green) was identified for the licensees failure to have appropriately managed risk activity as required by WM-AA-100-1000, Work Activity Risk Management, Revision 16. Specifically, plant personnel failed to reevaluate risk when a change in work scope occurred during outage work activities.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000331/2019-001-

LER 2019-001-00 for Duane Arnold Energy Center,

Manual Reactor Scram Due to Lowering Reactor Water Level 71153 Closed

PLANT STATUS

Unit 1 began the inspection period at rated thermal power. On April 13, 2019, the unit was down powered to 50 percent for a control rod sequence exchange. The unit was returned to rated thermal power on April 13, 2019. On April 20, 2019, the unit was manually shut down due to a loss of feedwater transient. The unit returned to rated thermal power on April 27, 2019, 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 performed plant status activities described in IMC 2515 Appendix D, Plant Status and conducted routine reviews using IP 71152, Problem Identification and Resolution. 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.

71111.01 - Adverse Weather Protection

Summer Readiness Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated summer readiness of offsite and alternate alternating current power systems on June 4, 2019

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) High pressure coolant injection system following maintenance on April 18, 2019 (2)

'A' core spray system on June 7, 2019

71111.04S - Equipment Alignment

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) Control building chilled water system on June 25, 2019

71111.05Q - Fire Protection

Quarterly Inspection (IP Section 03.01) (6 Samples)

The inspectors evaluated fire protection program implementation in the following selected areas:

(1) Fire Zone OAG-PA East on April 9, 2019

(2) Fire Zone 16A, B, C, D, and E (Pump House) on April 9, 2019

(3) Fire Zone OAG-PA South on April 9, 2019

(4) Fire Zone 4A and B (Reactor Building Elevation 812') on April 10, 2019

(5) Fire Zone 6A (Reactor Building Elevation 855') on April 10, 2019

(6) Fire Zone 5C (Reactor Building Elevation 833') on April 10, 2019

71111.06 - Flood Protection Measures

Inspection Activities - Internal Flooding (IP Section 02.02a.) (1 Sample)

The inspectors evaluated internal flooding mitigation protections in the:

(1) Reactor Building on June 4, 2019

71111.07A - Heat Sink Performance

Annual Review (IP Section 02.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1)

'B' residual heat removal service water and emergency service water stilling basin on June 19, 2019

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 a reactor plant power evolution and rod sequence exchange on April 14, 2019

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated licensed operator requalification activity on April 16, 2019

71111.12 - Maintenance Effectiveness

Routine Maintenance Effectiveness Inspection (IP Section 02.01) (3 Samples)

The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions:

(1)

'A' standby diesel generator aux cooling water relay on April 4, 2019 (2)

'B' diesel generator air compressor on May 28, 2019 (3)

'A' residual heat removal service water pump replacement on June 5, 2019

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated the risk assessments for the following planned and emergent work activities:

(1)

'A' and 'B' rod block monitor emergency work activities on May 8, 2019

(2) Control room annunciator emergency work activities on May 12, 2019 (3)

'B' moisture separator reheater drain tank drain valve emergent work activities on June 5, 2019

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 02.02) (2 Samples)

The inspectors evaluated the following operability determinations and functionality assessments:

(1) Condition Report 02313285; CV4421 'D' Outboard Main Steam Isolation Valve position lights indicate dual on May 5, 2019

(2) Condition Report 02317794; Torus Containment Post Accident Monitor on June 25, 2019

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) Control building chiller on June 26, 2019

71111.19 - Post-Maintenance Testing

Post Maintenance Test Sample (IP Section 03.01) (2 Samples)

The inspectors evaluated the following post maintenance tests:

(1)

'A' standby diesel generator 1G031/CW replacement post maintenance testing on April 4, 2019 (2)

'A' residual heat removal service water pump replacement post maintenance testing on June 7, 2019

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)

(1) Surveillance Test Procedure 3.3.6.1-06; PCIS Main Steam Line Isolation Logic System Functional Test on May 7, 2019

Surveillance Tests (other) (IP Section 03.01) (2 Samples)

(1) High Pressure Coolant Injection System Operability Test following maintenance on April 17, 2019

(2) Field portions of Standby Liquid Control Pump Test and Comprehensive Pump Test on May 30, 2019

71114.02 - Alert and Notification System Testing

Inspection Review (IP Section 02.01-02.04) (1 Sample)

(1) The inspectors evaluated the following maintenance and testing of the alert and notification system:

• Annual siren inspection and maintenance records for the period from April 2017 through April 2019

• Monthly alert notification system (siren) tests for the period from April 2017 through April 2019

71114.03 - Emergency Response Organization Staffing and Augmentation System

Inspection Review (IP Section 02.01-02.02) (1 Sample)

(1) The inspectors evaluated the readiness of the Emergency Response Organization.

71114.05 - Maintenance of Emergency Preparedness

Inspection Review (IP Section 02.01 - 02.11) (1 Sample)

(1) The inspectors evaluated the maintenance of the emergency preparedness program.

71114.06 - Drill Evaluation

Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01) (1 Sample)

(1) Emergency Response Organization training drill on May 22,

71124.01 - Radiological Hazard Assessment and Exposure Controls

Radiological Hazards Control and Work Coverage (IP Section 02.04) (1 Partial)

The inspectors evaluated in-plant radiological conditions during facility walkdowns and observation of radiological work activities.

(1)

(Partial)

• The inspectors evaluated the adequacy of surveys, radiation protection job coverage and contamination controls for valve work in the hot machine shop.

71124.02 - Occupational ALARA Planning and Controls

Radiological Work Planning (IP Section 02.01) (1 Sample)

The inspectors evaluated the licensees radiological work planning.

(1)

• Scaffold work

• Electrical maintenance

• Main steam isolation valves

• Refuel floor

• In service inspection and flow assisted corrosion exams and support

Verification of Dose Estimates and Exposure Tracking Systems (IP Section 02.02) (1 Sample)

The inspectors evaluated dose estimates and exposure tracking.

(1) The inspectors reviewed the following ALARA planning documents:

• 18-C1; Scaffolds in drywell and balance of plant

• 18-EMISC; Electrical work in drywell and balance of plant

• 18-MB; Main steam isolation valve inspections and repairs

• 18-R1; Perform refuel floor activities

• 18-S1S2; In service inspection and FAC exams and support

The inspectors reviewed the following radiological outcome evaluations:

• 18-C1; Scaffolds in drywell and balance of plant

• 18-EMISC; Electrical work in drywell and balance of plant

• 18-MB; main steam isolation valve inspections and repairs

• 18-S1S2; In service inspection and flow assisted corrosion exams and support

71124.04 - Occupational Dose Assessment

Internal Dosimetry (IP Section 02.03) (1 Sample)

The inspectors evaluated the internal dosimetry program implementation.

(1) Whole Body Counts

• 18-001-D

• 18-002-D

• 18-003-D

• 18-004-D

In-vitro internal monitoring

• None available

Dose assessments performed using air sampling and DAC-hr monitoring

• None available

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, 2018 through March 31, 2019)

EP01: Drill/Exercise Performance (IP Section 02.12) (1 Sample)

(1) 1st Quarter 2018 - 4th Quarter 2018

EP02: ERO Drill Participation (IP Section 02.13) (1 Sample)

(1) 1st Quarter 2018 - 4th Quarter 2018

EP03: Alert & Notification System Reliability (IP Section 02.14) (1 Sample)

(1) 1st Quarter 2018 - 4th Quarter 2018

OR01: Occupational Exposure Control Effectiveness Sample (IP Section 02.15) (1 Sample)

(1) 10/01/2018 - 03/31/2019

71152 - Problem Identification and Resolution

Annual Follow-Up of Selected Issues (IP Section 02.03) (2 Samples)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1) FLEX 480 VAC diesel generator performance issues (Coolant Hose Leak) on May 22, 2019

(2) Control building chillers issues on June 27, 2019

71153 - Follow-Up of Events and Notices of Enforcement Discretion Event Follow-Up (IP Section 03.01)

(1) Second stage heater tripped on May 2, 2019

Event Report (IP Section 03.02) (1 Sample)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 2019-001-00, Manual Reactor Scram due to Lowering Reactor Water Level (ADAMS accession: ML19171A191). The licensee documented two reportable events in this LER. The inspectors did not identify a performance deficiency or violation associated with the described invalid Group I isolation. The inspectors identified a finding associated with the manual scram.

INSPECTION RESULTS

Observation: A Control Building Chiller Issues 71152 The inspectors reviewed licensee problem identification and resolution activities associated with the A Control Building Chiller trips over the past 12 months. The licensees corrective action program documented issues associated with the 'A' Control Building Chiller. The licensee executed a plan of action setting up a data collection process by which they could track, prevent, and react to parameter fluctuations with a better understanding of the issue and potential solution(s). The inspectors determined the resolution of the A Control Building Chiller issues were deliberately pursued without any significant reduction of availability of this redundant train of safety equipment.

Observation: FLEX 480 VAC Generator Performance Issues 71152 The inspectors reviewed the licensee's problem identification and resolution activities associated with the FLEX diesel generator coolant leaks over the past 12 months. The licensees corrective action program documented several FLEX diesel generator coolant hose failures and recommended corrective actions. Ultimately the FLEX diesel generator coolant hoses were replaced with upgraded hoses and the procedures associated with testing and walking down the FLEX diesel generators were revised to de-energize the block heaters while stored in the heated FLEX buildings. The licensee causal analysis determined that the failure of the FLEX diesel generator coolant hoses occurred because the original equipment supplier installed non-high temperature heater hoses during original manufacture. Although the inspectors determined there were possible early opportunities to resolve this issue no deviation from the corrective action program standards were identified.

Failure to Notify Radiation Protection of Change In Work Scope Cornerstone Significance Cross-Cutting Aspect Report Section Occupational Radiation Safety

Green NCV 05000331/2019002-01 Open/Closed

[H.4] -

Teamwork 71124.01 The inspectors reviewed a self-revealed finding of very low safety significance (Green) and an associated Non-Cited Violation (NCV) of TS 5.4.1, Procedures, when the licensee failed to implement contamination control procedures when machining a contaminated main steam isolation valve disk without radiation protection knowledge.

Description:

On August 22, 2018, two individuals alarmed the personnel contamination monitors when exiting the Radiologically Controlled Area. The individuals were decontaminated, and internal dose assessments indicated minor intakes (less than two mrem) had occurred.

Upon investigation, it was determined that these individuals had been using a lathe to machine a contaminated main steam isolation valve disk during their shift without Radiation Protection knowledge. Procedure RP-AA-100-1002, Radiation Worker Instruction and Responsibilities, requires that radiation workers notify radiation protection prior to expanding work scope as well as prior to using grinding tools so that radiation protection can ensure appropriate controls are in place. The failure of the radiation workers to notify RP of the work being performed on the main steam isolation valve disk resulted in various radiological controls not being implemented. This included no contamination surveys being performed on the area of the disk being machined prior to or during machining as well as the installed high efficiency particulate air filter drawing a suction from the lathe not being used. Follow-up surveys of the disk indicated fixed contamination up to 40 mrad/hr beta and machine shop general contamination levels being higher than expected.

Corrective Actions: Corrective actions completed included the decontamination of the machine shop as well as distribution of a summary of the event and the lessons learned to site personnel.

Corrective Action References: CR 02277223, Increased Contamination Found in Hot Machine Shop

Performance Assessment:

Performance Deficiency: Radiation workers failed to inform radiation protection prior to expanding work scope as required by RP-AA-100-1002, Radiation Worker Instruction and Responsibilities.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Program & Process attribute of the Occupational Radiation Safety cornerstone. Specifically, the failure to notify radiation protection of changes in work scope prevented radiation protection from assessing the radiological hazards associated with the new work scope and implementing appropriate radiological controls to control those hazards, which could lead to unintended dose.

Significance: The inspectors assessed the significance of the finding using Appendix C, Occupational Radiation Safety SDP. Specifically, the inspectors determined that the finding was of very low safety significance (Green) because:

(1) it did not involve as-low-as-reasonably-achievable planning or work controls,

(2) there was no overexposure,

(3) there was no substantial potential for an overexposure, and

(4) the ability to assess dose was not compromised.

Cross-Cutting Aspect: H.4 - Teamwork: Individuals and work groups communicate and coordinate their activities within and across organizational boundaries to ensure nuclear safety is maintained. Teamwork failed because maintenance did not ensure radiation protection was made aware of a work evolution that involved disassembling and machining a contaminated piece of equipment.

Enforcement:

Violation: Technical Specification Section 5.4.1, requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978. Regulatory Guide 1.33, Revision 2, Appendix A, Section 7, addresses "Procedures for Control of Radioactivity" and Section 7.e.4 addresses "Contamination Control". The licensee established Procedure RP-AA-100-1002, Revision 6, 3/7/2017, to address radiation worker responsibilities, including those needed to maintain contamination control. RP-AA-100-1002, Revision 6, Step 4.6.2.10, requires that radiation protection be notified prior to expanding the work scope so radiation protection can identify the potential changes in radiological conditions and institute appropriate controls for worker protection.

Contrary to the above, on August 22, 2018, the licensee failed to implement Step 4.6.2.10 of procedure RP-AA-100-1002. Specifically, the licensee failed to notify radiation protection prior to expanding the work scope to include machining of a contaminated main steam isolation valve disk.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Failure to Manage Outage Risk Activities Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events

Green FIN 05000331/2019002-02 Open/Closed

[H.5] - Work Management 71153 A self-revealed finding of very low safety significance (i.e., Green) was identified for the licensees failure to have appropriately managed risk activity as required by WM-AA-100-1000, Work Activity Risk Management, Revision 16. Specifically, plant personnel failed to reevaluate risk when a change in work scope occurred during outage work activities.

Description:

In September of 2016, Condition Report 02154562 identified that the drain fitting elbow on a control air filter bowl associated with the condensate demineralizer system was leaking air.

The associated Work Order 40488545 was planned as a simple work order to replace the 90 degree copper/brass elbow at the bottom drain connection of the filter bowl during the May 2019 refueling outage 26. During the work process, the plastic drain port was identified in the work order completion notes as being severely degraded and cracked. A new air filter was ordered as a contingency, but work steps were not changed to allow for replacement of the air filter and the new filter would not fit in this application without modifications to the piping system to account for differences in height and length of the new filter. The entire manifold containing the filter and regulator was brought to the shop to complete repairs. The existing drain fitting was initially tightened, and pressure tested in the shop, but the air leak was still present. The decision was made to bore out the existing threaded connection in the polycarbonate filter bowl and drill and tap one size larger (1/4-20)and adapt a 90 degree elbow directly to the threaded connection of the bowl without using the insert, gasket, and retainer. This larger elbow was not the elbow reserved on the work order.

The reserved elbow had 1/8 female pipe threads and would not have adapted to the bowl connection. The elbow to bowl threaded connection was then coated with epoxy on both the external and internal surfaces of the bowl to elbow threaded connection as an additional barrier to prevent leakage. The completed repair was pressure tested in the shop with no leaks evident prior to installation in the plant.

On April 20, 2019, the control air filter bowl catastrophically failed sending a close signal to all condensate demineralizer filter flow control valves and initiated a total loss of feedwater transient. Both reactor feedwater pumps tripped on low suction pressure and reactor water level began lowering rapidly. Prior to the plant reaching the low level reactor trip setpoint, the operators manually tripped the reactor plant and restored water using alternative/emergency injections systems and restored plant parameter to a safe and stable condition. The licensees root cause evaluation stated the non-standard alteration of the filter bowl assembly contributed to the control air filter bowl failure, resultant loss of feedwater transient, and unplanned manual reactor trip.

Corrective Actions: The licensee completed repairs through an engineering change and hard piping the failed control air filter bowl. The licensee also entered an action to revise component criticality for in-line air filters that could cause a plant transient or unplanned limiting condition for operability as single point vulnerabilities in keeping with the licensee's work activity risk management process.

Corrective Action References: Condition Report 2311443; Manual Reactor Scram Due to Lowering Reactor Water Level

Performance Assessment:

Performance Deficiency: The failure to have appropriately managed risk activity as required by WM-AA-100-1000, Work Activity Risk Management, was a performance deficiency.

Specifically, the purpose of WM-AA-100-1000 was to appropriately manage the overall risk associated with outage work activities and step 4.7, Changing Scope of Work, required the reevaluation of risk associated if there is a significant change in work scope. During the outage repair work associated with a control air filter bowl, a significant change of work scope failed to reevaluate risk and the component ultimately failed catastrophically during the ensuing operating cycle.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human Performance attribute of the Initiating Events cornerstone. Specifically, the failure to appropriately manage a risk activity contributed to the catastrophic failure of the control air filter bowl and caused a total loss of feedwater transient and an unplanned reactor trip.

Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors assessed the significance of the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, dated October 7, 2016; and IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, dated June 19, 2012. Using Exhibit 1, Initiating Event Screen Questions, the inspectors determined that the finding caused a reactor trip and required a detailed risk evaluation.

The Senior Reactor Analysts performed a detailed risk evaluation using a recently updated Duane Arnold Standardized Plant Analysis Risk Model. The model was recently revised to update the late injection function and will become the model of record, version 8.55. The Senior Reactor Analysts evaluated the event using the transient event tree rather than the loss of main feedwater event tree because main feedwater was recoverable from the main control room and could support early injection if successfully recovered, a function that was not modeled in the loss of main feedwater event tree. The Senior Reactor Analysts set the transient initiating event frequency to 1.0 because the performance deficiency resulted in a transient event. Early feedwater recovery was modeled by modifying the basic event MFW-XHE-XO-ERROR, Operator fails to maintain feedwater injection and late feedwater recovery was modeled using the basic event PCS-XHE-XL-TRAN, Operator fails to recover PCS

[power conversion system] during Trans. The value of the early main feedwater recovery basic event was set to 2.2E-2. This basic event was estimated using Standardized Plant Analysis Risk Model-H, the NRCs method for human reliability analysis. The only performance shaping factor that was determined to be a performance driver was stress which was evaluated as high. The late recovery of the power conversion system basic event was modified to a value of 1E-3. For this basic event, the Senior Reactor Analysts assumed the operator failure would be dominated by action and the performance shaping factors were nominal. The basic event MSS-MSV-OC-STEAM, Steam Isolation Valves fail to remain open was set to True because the main steam isolation valves were closed by operators during the event. Recovery of the power conversion system includes re-opening the MSIVs and recovering main feedwater.

The conditional core damage probability was estimated at 7.2E-7. The contributing core damage sequences involved transients with the failure of long term heat removal but successful depressurization, transients without successful depressurization, and anticipated transients without scram. The risk contribution from core damage was determined to be of very low safety significance (i.e., Green).

The finding was also evaluated for large early release probability using IMC 0609 Appendix H, Containment Integrity Significance Determination Process, dated February 25, 2019. In NRC inspection report 05000331/2009009, the Senior Reactor Analysts previously determined that the Large Early Release Frequency multiplier in table 6.2 of Appendix H for high reactor coolant system pressure sequences was conservative and that a Large Early Release Frequency multiplier based on a depressurized reactor coolant system and a flooded drywell floor was more appropriate (<0.1). In that analysis, the Senior Reactor Analysts also determined that for some sequences, accident sequence timing would allow for effective evacuation before a release occurred. For the current case, the Senior Reactor Analysts reviewed an evacuation time estimate provided by the licensee and re-confirmed that the timing of some of the core damage sequences would allow for effective evacuation prior to release. For these reasons, the Senior Reactor Analysts concluded in this analysis that the conditional large early release probability was reasonably less than 1E-7 and the risk contribution from large early release was also of very low safety significance (i.e., Green).

The inspectors determined that the finding involved the cross-cutting aspect of Work Management (H.5) under the area of Human Performance (H). With their root cause evaluation, the licensee identified that organization failed to recognize the risk associated with using the non-standard alternation of control air filter bowl assembly. A self-revealed finding of very low safety significance (i.e., Green) was identified for the licensees failure to have coordinated the risk associated with work on control air filter bowl assembly. This led to a total loss of feedwater transient and unplanned reactor trip.

Cross-Cutting Aspect: H.5 - Work Management: The organization implements a process of planning, controlling, and executing work activities such that nuclear safety is the overriding priority. The work process includes the identification and management of risk commensurate to the work and the need for coordination with different groups or job activities. Specifically, the planning, control, and execution of work activities associated with the control air filter bowl repairs failed to appropriately identify and manage the original and altered work processes with commensurate with risk. A run to maintenance failure would and did result in an unplanned reactor trip.

Enforcement:

Inspectors did not identify a violation of regulatory requirements associated with this finding.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On May 2, 2019, the inspectors presented the emergency preparedness baseline inspection results to Mr. D. Curtland and other members of the licensee staff.

• On May 3, 2019, the inspectors presented the radiation protection inspection results to Mr. D. Curtland, Site Director, and other members of the licensee staff.

• On July 11, 2019, the inspectors presented the integrated inspection results to Mr. D. Curtland and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

71111.01

Corrective Action

Documents

Abnormal Operating Procedure 903; Severe Weather

Miscellaneous

2019 DAEC Seasonal Readiness Certification Letter

05/24/19

OP-AA-102-1002; Seasonal Readiness

71111.04

Drawings

BECH-M122

P&ID High Pressure Coolant Injection System Steam Side

Miscellaneous

BECH-M123

P&ID High Pressure Coolant Injection Water Side

Procedures

Surveillance Test Procedure 3.7.5-03A A Control Building

Chiller Operability Including Operation at Reduced Loading

Control Building HVAC System Electrical Line-Up

Operating Instruction 730 Control Building HVAC System

130

Surveillance Test Procedure 3.7.5-03 Control Building Chiller

Operability Including Operation at Reduced Loading

OI-152

Operating Instruction High Pressure Coolant Injection

System

119

71111.05Q Fire Plans

PFP-OE-757

Pre-Fire Plan OAG-PA East Elevation 757

PFP-OS-757

Pre-Fire Plans OAG-PA South Elevation 757

PFP-PH-757

Pre-Fire Plans Pump House

PFP-RB-812

Pre-Fire Plans Reactor Building Elevation 812

PFP-RB-833

Pre-Fire Plan Reactor Building Elevation 833

PFP-RB-855

Pre-Fire Plans Reactor Building Elevation 855

Procedures

ACP 1412.2

Control of Combustibles

71111.06

Corrective Action

Documents

Bases-EOP 3; Secondary Containment Control Guideline

DAEC-PSA-IF-10; Internal Flood Analysis Volume 1 of 2

Summary and Note Book

DAEC-PSA-IF-10; Internal Flood Analysis Volume 2 of 2

Flood Walkdown

71111.07A

Work Orders

River Water Supply Pump House Stilling Basin Inspect and

Clean

71111.11Q Corrective Action

Documents

Reactivity Management Plan Plant Down Power Sequence

Exchange

04/02/2019

IPOI-3; Power Operations

160

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

71111.12

Condition Report 02308401; 'A' Standby Diesel Generator

Aux Relate Temperature High

CR 02314135; Arcing from 1K010B 'A' D/G A/C Air

Compressor during Start

CR 02308401; A Standby Diesel Generator Aux Relate

Temperature High

CR 2314592; BECH-E105 not Updated per EMA A103647

Engineering

Changes

EC 2314592; Replacement of 1K010B-M with New Motor

Work Orders

Work Order 40647491; Replace 'A' RHRSW Pump and

Establish IST Reference Values

Work Request 94194131; Arcing from 1K010B 'A' D/G A/C

Air Compressor during Start

Work Order 40657678; 'A' Standby Diesel Generator

1G031/CW Replacement

71111.13

Corrective Action

Documents

Work Request 94191916; 'A' Rod Block Monitor Averaging

Card

Work Request 94191917; 'B' Rod Block Monitor Averaging

Card

'A' and 'B' Rod Block Monitor Work Plant

CR 02307849

'A' Rod Block Monitor Anomalous Behavior

CR 02307896

'B' Rod Block Monitor Anomalous Behavior

Miscellaneous

Work Request 94193937; Annunciator Horn for 1C05, 1C04,

and 1C03 will not Turn Off

Work Orders

Work Order 4066335; MSR Drain Tank Temporary Valve

Control

71111.15

Corrective Action

Documents

DAEC Operations Logbook

Condition Report 02313285; CV 4421 D Outboard Main

Steam Isolation Valve Position Lights Indicate Dual

BECH-E820<3>; Main Steam Isolation Valve Solenoid Valve

and Position SW. Conn. Diagram

APED-A71-003<11>; Elementary Diagram Nuclear Steam

Supply Shutoff System

APED-A71-003<11A>; Elementary Diagram Nuclear Steam

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

Supply Shutoff System

Technical Specification 3.3.3.1; Post Accident Monitoring

Instrumentation (and Bases); Amendment 25

DAEC Operations Logbook; June 13-June 17, 2019

Technical Specification 3.3.3.1; Post Accident Monitoring

Instrument (and Bases); Amendment 25

71111.18

Drawings

BECH-M144<1>

06/19/2019

BECH-M169 sh.<4>

06/19/2019

Engineering

Changes

Non-Essential Chiller

71111.19

Work Orders

Work Order 40657678; 'A' Standby Diesel Generator

1G031/CW Replacement

Work Order 40647491; Replace 'A' RHRSW Pump and

Establish IST Reference Values

71111.22

Corrective Action

Documents

Surveillance Test Procedure 3.3.6.1-06; PCIS Main Steam

Line Isolation Logic System Functional Test

Procedures

Surveillance Test Procedure 3.1.7-04; Standby Liquid

Control Pump Test and Comprehensive Pump Test

STP 3.5.1-10

HPCI System Operability Test and Comprehensive Pump

Test

STP NS520001

HPCI System Leakage Inspection Walkdown

71114.02

Corrective Action

Documents

CR 02222088

Create Work Order for 2017 Siren Replacements

CR 02239448

Siren 07C (1301) Inoperable for December Monthly Test

CR 02258158

Large Number of Amplifier Failures for April 2018 Monthly

Test

Miscellaneous

Annual Siren Inspection and Maintenance Records

04/01/2017 -

04/01/2019

Monthly Alert Notification System (Siren) Test Results

04/01/2017 -

04/01/2019

FEMA Letter

Duane Arnold Route Alerting Approval Letter

2/17/2012

FEMA Letter

Approval of DAEC Public Information Program Modification

2/04/2019

FEMA REP-10

Design Report

Appendix P

Duane Arnold Energy Center Outdoor Warning System/Alert

and Notification System (ANS) Upgrade Project

01/06/2009

71114.02

Miscellaneous

Iowa Homeland

Security and

Emergency

Management

Agency Letter

DAEC Siren Control Upgrade Project

05/24/2018

P100002777

ANS Public Information Postcard

01/01/2019

Procedures

EPDM 1013

Emergency Siren (ANS) and Siren Sign Program

GMP-ELEC-34

Whelan High Power Voice and Siren System

GMP-ELEC-34,

Section A

Siren Inspection

GMP-ELEC-34,

Section B

Voice and Siren Testing

GMP-ELEC-34,

Section C

Repair and Troubleshooting

71114.03

Corrective Action

Documents

CR 02214832

EP Audit - Five ERO Positions are not 3 Deep

CR 02274504

EP Procedures Conflict with Emergency Plan

Miscellaneous

ERO Augmentation Call In Drill Reports

04/01/2017 -

04/01/2019

DAEC ERO Team Roster

03/27/2019

ERO Member Training/Qualification Records (sample - 20

records)

05/01/2019

Quarterly ERO Call-In Drill Reports

2nd Quarter

2017 - 1st

Quarter 2019

Procedures

DAEC

Emergency Plan,

Section H

Emergency Facilities Staffing, Activation and Equipment

EP-AA-107

Fleet Emergency Response Organization (ERO) Training

Program

EPDM 1009

Emergency Response Organization (ERO) Training and

Qualification Program

EPDM 1016

ERO Augmentation Drill and Testing Program

EPIP 6.1

Drill and Exercise Program

Self-Assessments

DAEC On-Shift Staffing Analysis

71114.05

Corrective Action

CR 02206959

17TD2SIM -CAQ - Controller Deficiencies

Documents

CR 02207927

Controller Prompting During Tabletop

CR 02215168

State and County Concerns for Emergency Planning

CR 02258889

All Call Phone System Server Issues

CR 02305686

19TD1-CR Event Response Team Pagers did not Activate

CR 2206954

Shift Communicator Identified Incorrect EAL to Simulated Off

Site

PCR 02299716

DAEC Plan "G" - Public Education and Information

RWT 2249730

2018 Emergency Planning Generic RWT

Miscellaneous

KLD TR-993

Duane Arnold Energy Center 2018 Population Update

Analysis

03/08/2018

KLD-TR-910

Duane Arnold Energy Center Development of Evacuation

Time Estimates for Revised EPZ Boundary

03/09/2017

Procedures

DAEC Emergency Plan

EP-AA-100-1001

Guidelines for Maintaining Emergency Preparedness

EPIP 6.2

Maintenance of Emergency Response Facilities and

Equipment

Self-Assessments

2018 DAEC Onsite Medical Drill After-Action

Report/Improvement Plan

2/04/18

KLD-1071

2019 Population Update Analysis

03/07/2019

NEP#-2017-007

2017 ERO Training Drill #1_Rev 1

07/25/2017

NEP#-2017-014

2017 ERO Training Drill #2_Rev 1

08/10/2017

NEP#-2017-017

2017 Off Year Exercise (OEX) Report

09/29/2017

NEP#-2018-006

2018 Dress Rehearsal (18DR)

04/07/2018

NEP#-2018-008

2018 Exercise (18EX) Final Report

05/21/2018

NEP#-2018-011

2018 Drill (18TD1) Final Report

07/25/2018

PDA 17-004

DAEC Nuclear Assurance Report - Emergency

Preparedness

07/20/2017

PDA 18-007

DAEC Nuclear Assurance Report - Emergency

Preparedness

08/13/2018

71114.06

Miscellaneous

Duane Arnold Energy Center Training Drill 19TD2

Drill/Exercise Program

NRC Form 361; Reactor Plant Event Notification Worksheet

Note-05; Duane Arnold Energy Center Emergency

Notification

71124.01

Corrective Action

AR 02277223

Increased Contamination Found In Hot Machine Shop

Documents

Procedures

RP-AA-100-1002

Radiation Worker Instruction and Responsibilities

Radiation

Surveys

PDA-M-

20180822-3

Hot Machine Shop Contamination Survey

08/22/2018

PDA-M-

20180823-1

Main Steam Isolation Valve Piston Contamination Follow Up

08/23/2018

Radiation Work

Permits (RWPs)

18-0051

Routine Work and Inspections

71124.02

ALARA Plans

18-C1

Scaffolds in Drywell and Balance of Plant

18-EMISC

Electrical work in Drywell and Balance of Plant

18-MB

Main Steam Isolation Valve Inspections and Repairs

18-R1

Refuel Floor Activities

18-S1S2

In Service Inspection and Flow Assisted Corrosion Exams

and Support

71124.04

Calculations

Radiological

Engineering

Calculation 18-

001-D

Estimating the Committed Effective Dose Equivalent

Exposure to Individual #1 in Main Steam Isolation Valve

Machining Event

08/27/2018

Radiological

Engineering

Calculation 18-

2-D

Estimating Committed Effective Dose Equivalent Exposure

to Individual #2 in Main Steam Isolation Valve Machining

Event

08/27/2018

Radiological

Engineering

Calculation 18-

003-D

Estimating Committed Effective Dose Equivalent Exposure

to Individual #1 in Reactor Head Seal Event

09/21/2018

Radiological

Engineering

Calculation 18-

004-D

Estimating Committed Effective Dose Equivalent Exposure

to Individual #2 in Reactor Head Seal Event

09/21/2018

Calibration

Records

Fastscan Whole Body Counter Quality Assurance Sample

Report

08/23/2018 -

09/20/2018

Fastscan Whole Body Counter Calibration Report

10/03/2017

Procedures

HPP 3104.02

Personnel Contamination Monitoring, Whole Body Counting

and Decontamination

HPP 3109.72

Operation of FastScan Whole Body Counter

Radiation

Surveys

GEL Sample ID

2167001

GEL Laboratories Radiological Certificate of Analysis

11/15/2018

Sample 18-514

Refuel Floor High Contamination Area Gamma Analysis

09/20/2018

71151

Corrective Action

Documents

CR 2246165

Level 1 Assessment - Drill and Exercise Performance

(DEP-PI)

CR 2246166

Potential Trend - DEP-PI Recovery Plan

LIA 2283966

LIA: Review Recent PB DEP-PI Failure

Miscellaneous

NRC Performance Indicator Data; Emergency Preparedness

- Drill/Exercise Performance

1st Quarter

2018 - 4th

Quarter 2018

NRC Performance Indicator Data; Emergency Preparedness

- ERO Readiness

1st Quarter

2018 - 4th

Quarter 2018

NRC Performance Indicator Data; Emergency Preparedness

- Alert and Notification System Reliability

1st Quarter

2018 - 4th

Quarter 2018

NG-001L

NRC PI Data Calculation, Review and Approval, for Second

Quarter 2018 through First Quarter 2019

Procedures

-

EPDM

1010

EP Department Performance Indicators

71152

Corrective Action

Documents

CR 02249054; 'A' & 'B' FLEX Diesel Block Heater

CR 02307659; 'B' FLEX Diesel Generator Major Coolant

Leak

CR 02270741; 'A' FLEX Diesel Engine Block Heater Hose

Failure

CR 02307857; Trend-FLEX 480 VAC Generator

Performance Issues

CR 02273618; 'A' FLEX Diesel Generator Water Hose

Replacement

CR 02273619; 'B' FLEX Diesel Generator Water Hose

Replacement

NS240502A; FLEX 480VAC Diesel Generator 1G101A

Functional Test

NS240502B; FLEX 480VAC Diesel Generator 1G101B

Functional Test

NS240503; FLEX Diesel Generator Monthly Walkdown

NS240506A; FLEX 480VAC Diesel Generator 1G10A Load

Test

NS240506B; FLEX 480VAC Diesel Generator 1G10B Load

Test

ER02307857; Trend-FLEX 480 VAC Generator Performance

Issues

Procedures

MA-AA-100-1011-F03

Work Orders

Work Order 40610900-01; Quality Record

Work Order 40616626-01; Monthly Inspection with ESW

Secured

71153

Corrective Action

Documents

Abnormal Operating Procedure 255.2 Power/Reactivity

Abnormal Change

1C07B Moisture Separator Re-heater Second Stage Drain

Tanks 1T-92A to 1T-92B Pressure Differential High

Operating Shift Logs; May 1, 2019

Operating Shift White Paper on Moisture Separator Drain

Tank High dp

BECH-E108<004A>; Steam and Condensate System

BECH-M104<2>; Feedwater Heaters 1E003A, 4A, 5A, 6A

Miscellaneous

Work Order 40488545-01; 1C80 Repair Leak Issue

MA-AA-100; Conduct of Maintenance

WM-AA-200; Work Management Process Overview

WM-AA-100-1000; Work Activity Risk Management

EN-54012; DAEC Loss of Feed Reactor Trip

Event Notification#54012; Loss of Feed Water Trip

04/20/2019