IR 05000277/2016003

Integrated Inspection Report 05000277/2016003 and 05000278/2016003

ML16309A002
Person / Time
Site:	Peach Bottom
Issue date:	11/03/2016
From:	Daniel Schroeder Reactor Projects Region 1 Branch 4
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Schroeder D
References
IR 2016003
Download: ML16309A002 (28)

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UNITED STATES NUCLEAR REGULATORY COMMISSION

REGION I

2100 RENAISSANCE BLVD.

KING OF PRUSSIA, PA 19406-2713 November 3, 2016 Mr. Bryan Hanson Senior Vice President, Exelon Generation, LLC President and Chief Nuclear Officer, Exelon Nuclear 4300 Winfield Rd.

Warrenville, IL 60555 SUBJECT: PEACH BOTTOM ATOMIC POWER STATION - INTEGRATED INSPECTION REPORT 05000277/2016003 AND 05000278/2016003

Dear Mr. Hanson:

On September 30, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Peach Bottom Atomic Power Station (PB), Units 2 and 3. On October 14, 2016, the NRC inspectors discussed the results of this inspection with Mr. Michael Massaro, Peach Bottom Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

NRC inspectors documented one finding of very low safety significance (Green) in this report.

The finding did not involve a violation of NRC requirements. If you disagree with the 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 I, and the NRC Resident Inspector at Peach Bottom.

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 the NRC Public Document Room in accordance with 10 Code of Federal Regulations (CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-56

Enclosure:

Inspection Report 05000277/2016003 and 05000278/2016003 w/Attachment: Supplementary Information

REGION I==

Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-56 Report No. 05000277/2016003 and 05000278/2016003 Licensee: Exelon Generation Company, LLC Facility: Peach Bottom Atomic Power Station, Units 2 and 3 Location: Delta, Pennsylvania Dates: July 1, 2016 through September 30, 2016 Inspectors: J. Heinly, Senior Resident Inspector B. Smith, Resident Inspector Approved By: Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure

SUMMARY

Inspection Report 05000277/2016003, 05000278/2016003; 07/01/2016 - 09/30/2016;

Peach Bottom Atomic Power Station (PB), Units 2 and 3; Follow-Up of Events and Notices of Enforcement Discretion.

This report covered a three-month period of inspection by resident inspectors. The inspectors identified one finding, which was of very low safety significance (Green). The significance of most findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red)and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP), dated April 29, 2015. Cross-cutting aspects are determined using IMC 0310,

Aspects Within Cross-Cutting Areas, dated December 4, 2014. All violations of the Nuclear Regulatory Commission (NRC) requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated August 1, 2016. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649,

Reactor Oversight Process, Revision 6.

Cornerstone: Initiating Events

A self-revealing finding of very low safety significance (Green) was identified for Exelons failure to maintain the Unit 2 C reactor feed pump (RFP) Woodward controller secondary power supply in accordance with PES-S-002, Exelon Shelf Life Program. Specifically, on May 27, 2016, the Unit 2 C RFP experienced speed oscillations due to an age-related failure of the Woodward controller secondary power supply, which resulted in an automatic recirculation runback to 53 percent rated thermal power (RTP). The power supply contained an electrolytic capacitor that had exceeded its shelf life per PES-S-002. This issue was entered into Exelons corrective action program (CAP) under issue report (IR) 02691322.

Exelons corrective actions included replacement of the faulted power supply and an extent of condition (EOC) review of proper expiration date entry for shelf life program components.

The finding was more than minor because it was associated with the equipment performance attribute of the Initiating Events cornerstone and affected the cornerstones objective of limiting the likelihood of events that upset plant stability during power operations. The inspectors evaluated the finding in accordance with Exhibit 1 of Inspection Manual Chapter (IMC) 0609, Appendix A, SDP for Findings At-Power, and determined the finding was of very low safety significance (Green) because it did not cause a reactor trip and the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition. The inspectors determined that no cross-cutting aspect was applicable to this finding because the performance deficiency (PD) was not indicative of current performance. The PD occurred between 1997 and 1999 when the power supply expiration date was incorrectly coded in Exelons work management process in accordance with PES-S-002. (Section 4OA3)

Other Findings

None.

REPORT DETAILS

Summary of Plant Status

Unit 2 began the inspection period at 100 percent RTP. On September 2, 2016, operators reduced power to 59 percent RTP to support waterbox cleaning in order to improve degraded vacuum in the main condenser. The unit was returned to full power on September 3, 2016. The unit remained at 100 percent RTP except for brief periods to support planned testing and control rod pattern adjustments. The unit then began end-of-cycle coastdown for refueling outage (RFO) 2R21 on September 28, 2016, and ended the inspection period at 98 percent RTP.

Unit 3 began the inspection period at 100 percent RTP. On July 29, 2016, operators responded to a high differential alarm on the 3C intake structure traveling screen by reducing power to 84 percent RTP and removing the 3C circulating water pump from service. The unit was returned to full power that same day following the repairs. Unit 3 remained at 100 percent RTP until the end of the inspection period, except for brief periods to support planned testing and control rod pattern adjustments.

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R01 Adverse Weather Protection

External Flooding

a. Inspection Scope

On August 29, 2016, the inspectors performed an inspection of the external flood protection measures for PB. The inspectors reviewed technical specification (TS),procedures, design documents, and Updated Final Safety Analysis Report (UFSAR) Chapter 2.3.4.5 and Appendix C.2.5.4, which depict the design flood levels and protection areas containing safety-related equipment. The inspectors conducted a walkdown of the internal and external features of the safety-related pump structure for Units 2 and 3 to ensure the stations flood protection measures were controlled in accordance with the design specifications. The inspectors also reviewed operating procedures for mitigating external flooding during severe weather to determine if Exelon planned or established adequate measures to protect against external flooding events.

Documents reviewed for each section of this inspection report are listed in the

.

b. Findings

No findings were identified.

1R04 Equipment Alignment

Partial System Walkdowns (71111.04Q - 5 samples)

a. Inspection Scope

The inspectors performed partial walkdowns of the following systems:

• Unit 2 and Unit 3 A standby gas treatment (SBGT) train with the B SBGT train out of service (OOS) on July 7, 2016

• Unit 2 and Unit 3 A and B emergency cooling tower cells with the C cell OOS on July 25, 2016

• Unit 2 reactor core isolation cooling (RCIC) system during high-pressure coolant injection (HPCI) system testing on August 25, 2016

• Offsite power source alignment with the Unit 3 start-up source removed from service on September 13, 2016

• Unit 2 and Unit 3 A main control room emergency ventilation system during a planned E-4 emergency diesel generator (EDG) overhaul on September 22, 2016 The inspectors selected these systems based on their risk-significance relative to the Reactor Safety cornerstones at the time they were inspected. The inspectors reviewed applicable operating procedures, system diagrams, the UFSAR, TSs, work orders (WOs), IRs, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted the systems performance of its intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. The inspectors also reviewed whether Exelon staff had properly identified equipment issues and entered them into the CAP for resolution with the appropriate significance characterization.

b. Findings

No findings were identified.

1R05 Fire Protection

.1 Resident Inspector Quarterly Walkdowns

a. Inspection Scope

The inspectors conducted tours of the areas listed below to assess the material condition and operational status of fire protection features. The inspectors verified that Exelon controlled combustible materials and ignition sources in accordance with administrative procedures. The inspectors verified that fire protection and suppression equipment was available for use as specified in the area pre-fire plan, and passive fire barriers were maintained in good material condition. The inspectors also verified that station personnel implemented compensatory measures for OOS, degraded or inoperable fire protection equipment, as applicable, in accordance with procedures.

• Unit 3 hydraulic control unit area on July 25, 2016

• Unit 2 standby liquid control room on July 25, 2016

• Unit 2 and Unit 3 EDG building (E-1, E-2, E-3, and E-4 rooms) on July 26, 2016

• Unit 3 C residual heat removal room on July 28, 2016

• Unit 2 and Unit 3 station blackout building on August 8, 2016

• Unit 3 south isolation valve room on August 24, 2016

.2 Fire Protection - Drill Observation

a. Inspection Scope

The inspectors observed a fire brigade drill scenario conducted on September 20, 2016, that involved a breaker fire on the 135 elevation of the Unit 2 turbine building. The inspectors evaluated the readiness of the plant fire brigade to fight fires. The inspectors verified that PB personnel identified deficiencies, openly discussed them in a self-critical manner at the debrief, and took appropriate corrective actions as required. The inspectors evaluated the following specific attributes of the drill:

• Proper use of turnout gear and self-contained breathing apparatus

• Proper use and layout of fire hoses

• Employment of appropriate fire-fighting techniques

• Sufficient fire-fighting equipment brought to the scene

• Effectiveness of command and control

• Search for victims and propagation of the fire into other plant areas

• Smoke removal operations

• Utilization of pre-planned strategies

• Adherence to the pre-planned drill scenario

• Drill objectives met The inspectors also evaluated the fire brigades actions to determine whether these actions were in accordance with Exelons fire-fighting strategies.

b. Findings

No findings were identified.

1R06 Flood Protection Measures

Internal Flooding Review

a. Inspection Scope

The inspectors reviewed the UFSAR, the site flooding analysis, and plant procedures to identify internal flooding susceptibilities for the site. The inspectors review focused on the Unit 3 RCIC room on August 1, 2016. The inspectors verified the adequacy of equipment seals located below the flood line, floor and water penetration seals, watertight door seals, common drain lines and sumps, sump pumps, level alarms, control circuits, and temporary or removable flood barriers. It assessed the adequacy of operator actions that Exelon had identified as necessary to cope with flooding in this area and also reviewed the CAP to determine if Exelon was identifying and correcting problems associated with both flood mitigation features and site procedures for responding to flooding.

b. Findings

No findings were identified.

1R11 Licensed Operator Requalification Program and Licensed Operator Performance

.1 Quarterly Review of Licensed Operator Requalification Testing and Training

a. Inspection Scope

The inspectors observed licensed operator simulator training scenarios on August 24, 2016, which included initiating events requiring primary and secondary containment control and reactor pressure vessel flooding actions. The inspectors evaluated operator performance during the simulated event and verified completion of risk significant operator actions, including the use of abnormal and emergency operating procedures. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and degrading plant conditions, and the oversight and direction provided by the control room supervisor. The inspectors verified the accuracy and timeliness of the emergency classifications made by the shift manager and the TS action statements entered by the shift technical advisor. Additionally, the inspectors assessed the ability of the crew and training staff to identify and document crew performance problems.

b. Findings

No findings were identified.

.2 Quarterly Review of Licensed Operator Performance in the Main Control Room

a. Inspection Scope

The inspectors observed and reviewed the licensed operator performance from the main control room during the reactivity evolution listed below. The inspectors observed use of and compliance with procedures, crew communications, interpretation, diagnosis, and understanding of plant alarms, use of human error prevention techniques, documentation of activities, and management oversight of the evolution to verify that the crew was following procedures and plant expectations for conduct of operations.

• Unit 2 removal of the 5th stage A and C feedwater heaters on August 21, 2016

• Unit 2 downpowers to improve degraded main condenser vacuum on August 24-26 , 2016 The inspectors observed control room briefings and power changes. Additionally, the inspectors observed power changes to verify that procedure use, crew communications, and coordination of activities between work groups similarly met established expectations and standards.

b. Findings

No findings were identified.

1R12 Maintenance Effectiveness

a. Inspection Scope

The inspectors reviewed the samples listed below to assess the effectiveness of maintenance activities on structures, systems, and components (SSCs) performance and reliability. The inspectors reviewed system health reports, CAP documents, maintenance WOs, and maintenance rule (MR) basis documents to ensure that Exelon was identifying and properly evaluating performance problems within the scope of the MR. For each sample selected, the inspectors verified that the SSC was properly scoped into the MR in accordance with 10 CFR 50.65 and verified that the (a)(2)performance criteria established by the Exelon staff was reasonable. As applicable, for SSCs classified as (a)(1), the inspectors assessed the adequacy of goals and corrective actions to return these SSCs to (a)(2) status. Additionally, the inspectors ensured that Exelon staff was identifying and addressing common cause failures that occurred within and across maintenance rule (MR) system boundaries.

• Unit 2 and Unit 3 B main stack radiation monitor failures on August 16, 2016

• Unit 2 and Unit 3 emergency service water (ESW) pump failures and quality control program on August 22-26, 2016

• Unit 2 and Unit 3 control room envelope system review on September 14-16, 2016

b. Findings

No findings were identified.

1R13 Maintenance Risk Assessments and Emergent Work Control

a. Inspection Scope

The inspectors reviewed station evaluation and management of plant risk for the maintenance and emergent work activities listed below to verify that Exelon performed the appropriate risk assessments prior to removing equipment for work. The inspectors selected these activities based on potential risk significance relative to the Reactor Safety cornerstones. As applicable for each activity, the inspectors verified that Exelon personnel performed risk assessments as required by 10 CFR 50.65(a)(4) and that the assessments were accurate and complete. When Exelon performed emergent work, the inspectors verified that operations personnel promptly assessed and managed plant risk.

The inspectors reviewed the scope of maintenance work and discussed the results of the assessment with the stations probabilistic risk analyst to verify plant conditions were consistent with the risk assessment. The inspectors also reviewed the TS requirements and inspected portions of redundant safety systems, when applicable, to verify risk analysis assumptions were valid and applicable requirements were met.

• Unit 2 and Unit 3 planned extended diesel driven fire pump (DDFP) system outage window (SOW) and Unit 2 D high pressure service water (HPSW) pump OOS on July 6, 2016

• Elevated risk, Unit 2 during instrument nitrogen system check valve in-service test on July 20, 2016

• Unit 2 and Unit 3 planned maintenance on the E-2 EDG on August 2, 2016

• Yellow risk on Unit 2 during the A HPSW / RHR emergent SOW on August 17, 2016

• Unit 3 HPCI unplanned maintenance on September 27, 2016

b. Findings

No findings were identified.

1R15 Operability Determinations and Functionality Assessments

a. Inspection Scope

The inspectors reviewed operability determinations (ODs) for the following degraded or non-conforming conditions based on the risk significance of the associated components and systems:

• Unit 2 and Unit 3 emergency service water micro switch failures on July 6, 2016

• Unit 3 elevated temperatures in the reactor water cleanup area and steam tunnel on July 20, 2016

• Unit 2 and Unit 3 E-2 EDG scissor lift seismic qualification on August 23, 2016

• Unit 2 and Unit 3 DDFP flame arrestor flood bypass on August 26, 2016

• Unit 2 and Unit 3 operator work arounds on September 1, 2016 The inspectors evaluated the technical adequacy of the ODs to assess whether TS operability was properly justified and the subject component or system remained available such that no unrecognized increase in risk occurred. The inspectors compared the operability and design criteria in the appropriate sections of the TSs and UFSAR to Exelons evaluations to determine whether the components or systems were operable.

The inspectors confirmed, where appropriate, compliance with bounding limitations associated with the evaluations, including compliance with in-service testing requirements. Where compensatory measures were required to maintain operability, such as in the case of operator workarounds, the inspectors determined whether the measures in place would function as intended and were properly controlled by Exelon.

b. Findings

No findings were identified.

1R18 Plant Modifications

Permanent Modifications

a. Inspection Scope

The inspectors reviewed the permanent modification of the DDFP controller, on July 7, 2016, to determine whether the modification affected the safety function of systems that are important to safety. The inspectors reviewed 10 CFR 50.59 documentation and post-modification testing results, and conducted field walkdowns of the modification to verify that the permanent modification did not degrade the design bases, licensing bases, and performance capability of the affected system.

b. Findings

No findings were identified

1R19 Post-Maintenance Testing

a. Inspection Scope

The inspectors reviewed the post-maintenance tests (PMTs) for the maintenance activities listed below to verify that procedures and test activities tested the safety functions that may have been affected by the maintenance activity, that the acceptance criteria in the procedure were consistent with the information in the applicable licensing basis and/or design basis documents, and that the test results were properly reviewed and accepted and problems were appropriately documented. The inspectors also walked down the affected job site, observed the pre-job brief and post-job critique where possible, confirmed work site cleanliness was maintained, and witnessed the test or reviewed test data to verify quality control hold point were performed and checked, and that results adequately demonstrated restoration of the affected safety functions.

• Unit 2 RCIC following valve maintenance on July 20, 2016

• Unit 2 and Unit 3 E-2 EDG SOW on August 3, 2016

• Unit 2 and Unit 3 B main stack radiation monitor repairs on August 12, 2016

• Unit 2 A standby liquid control pump gasket replacement on September 1, 2016

• Unit 2 and Unit 3 E-4 EDG SOW on September 26, 2016

• Unit 3 HPCI pipe replacement on September 29, 2016

b. Findings

No findings were identified.

1R22 Surveillance Testing

a. Inspection Scope

The inspectors observed performance of surveillance test (STs) and/or reviewed test data of selected risk-significant structures, systems, and components (SSCs) to assess whether test results satisfied TSs, the UFSAR, and Exelon procedure requirements. The inspectors verified that test acceptance criteria were clear, tests demonstrated operational readiness and were consistent with design documentation, test instrumentation had current calibrations and the range and accuracy for the application, tests were performed as written, and applicable test prerequisites were satisfied. Upon test completion, the inspectors considered whether the test results supported that equipment was capable of performing the required safety functions. The inspectors reviewed the following STs:

• Unit 2 RHR A loop pump, valve, and flow (PVF) test on July 8, 2016 (IST)

• Unit 2 and Unit 3 seismic monitor calibration and functional check on August 3-4, 2016 (ST)

• Unit 3 containment atmosphere control valve stroke time testing on August 12, 2016 (IST)

• Unit 3 RHR B loop, PVF test on August 25, 2016 (IST)

b. Findings

No findings were identified.

4OA1 Performance Indicator Verification

.1 Safety System Functional Failures (2 samples)

a. Inspection Scope

The inspectors sampled PBs submittals for the Safety System Functional Failures performance indicator (PI) for both Unit 2 and Unit 3 for the period of July 1, 2015 through June 30, 2016. To determine the accuracy of the PI data reported during those periods, inspectors used definitions and guidance contained in the Nuclear Energy Institute (NEI) Document 99-02, Regulatory Assessment PI Guideline, Revision 7, and NUREG-1022, Revision 3 Event Reporting Guidelines 10 CFR 50.72 and 10 CFR 50.73." The inspectors reviewed PBAPS's operator narrative logs, operability assessments, MR records, maintenance WOs, CRs, event reports and NRC integrated inspection reports to validate the accuracy of the submittals.

b. Findings

No findings were identified.

.2 Mitigating Systems Performance Index (10 samples)

a. Inspection Scope

The inspectors reviewed Exelons submittal of the Mitigating Systems Performance Index for the following systems for the period of July 1, 2015 through June 30, 2016:

• Unit 2 and Unit 3 Emergency AC Power Systems (MS06)

• Unit 2 and Unit 3 HPCI Systems (MS07)

• Unit 2 and Unit 3 RCIC Systems (MS08)

• Unit 2 and Unit 3 RHR Systems (MS09)

• Unit 2 and Unit 3 Cooling Water Systems (MS10)

To determine the accuracy of the PI data reported during those periods, the inspectors used definitions and guidance contained in NEI Document 99-02, Regulatory Assessment PI Guideline, Revision 7. The inspectors also reviewed Exelons operator narrative logs, condition reports, mitigating systems performance index derivation reports, event reports, and NRC integrated inspection reports to validate the accuracy of the submittals.

b. Findings

No findings were identified.

4OA2 Problem Identification and Resolution

.1 Routine Review of Problem Identification and Resolution Activities

a. Inspection Scope

As required by Inspection Procedure 71152, Problem Identification and Resolution, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify that Exelon entered issues into the CAP at an appropriate threshold, gave adequate attention to timely corrective actions, and identified and addressed adverse trends. In order to assist with the identification of repetitive equipment failures and specific human performance issues for follow-up, the inspectors performed a daily screening of items entered into the CAP and periodically attended condition report screening meetings. The inspectors also confirmed, on a sampling basis, that, as applicable, for identified defects and non-conformances, Exelon performed an evaluation in accordance with 10 CFR Part 21.

b. Findings

No findings were identified.

.2 Annual Sample: Maintenance Department Decline in Standards

a. Inspection Scope

The inspectors performed an in-depth review of Exelons analysis and corrective actions associated with condition report IR 2476355, Maintenance Organization Subtle Decline in Standards, written on March 30, 2015. Specifically, PB maintenance department managers and supervisors were not always holding themselves and their departments accountable to high standards in the areas of IR generation and timeliness, clearance and tagging, troubleshooting, and meeting behaviors.

The inspectors assessed Exelons problem identification threshold, apparent cause evaluation (ACE), and the prioritization and timeliness of Exelons corrective actions to determine whether Exelon was appropriately identifying, characterizing, and correcting problems associated with this issue, and whether the planned or completed corrective actions were appropriate. The inspectors compared the actions taken to the requirements of Exelons CAP and 10 CFR 50, Appendix B. In addition, the inspectors reviewed subsequent IRs, observed subsequent troubleshooting, clearance and tagging activities, and interviewed maintenance and work management personnel to assess the effectiveness of the implemented corrective actions.

b. Findings and Observations

No findings were identified.

On April 10, 2015, Exelon initiated an ACE to address a decline in standards within the maintenance department in the areas of IR generation and timeliness, clearance and tagging, troubleshooting, and meeting behaviors. The ACE concluded that gaps in performance areas were at times considered less consequential and inconsistently addressed through performance management. In addition, the ACE concluded through interviews that supervisors and managers believed performance management tools could be improved to allow more effective performance management of individuals.

Exelon implemented corrective actions, including actions such as a roll down communications from senior management reinforcing the consequence of not completing the aforementioned tasks with precision and rigor and the development of a template for department alignment plans including metrics.

The inspectors reviewed Exelons corrective actions and have noted improvement within performance of the maintenance department. In general, IR generation and timeliness have improved, there have been a decrease in clearance and tagging issues over the past year, and troubleshooting has been more rigorous to identify causes for equipment failures. The inspectors did identify a PD for not generating IRs for defective commercial-grade micro switches used in safety-related 4kV breakers in accordance with PI-AA-120, Corrective Action Procedure. PI-AA-120 states that IRs are required to be initiated if a safety-related or critical component fails a bench test. Electrical maintenance technicians were appropriately discarding defective micro switches that had failed bench testing, however, were not initiating IRs so that Exelon could trend the issues in the CAP. The inspectors determined that the PD was minor because although electrical maintenance had not initiated IRs to be trended in the CAP, there was not an adverse impact to 4kV safety-related breaker performance as a specific result of the PD.

Exelon generated IR 2711781 to document the inspectors concern.

.3 Annual Sample: Issue Report Initiation for Single Point Vulnerability Instruments

a. Inspection Scope

The inspectors performed an in-depth review of Exelons analysis and corrective actions associated with condition report IR 2485800, IR Initiation for Out-of-Calibration Instruments, written on April 15, 2015. Specifically, during an NRC Problem Identification and Resolution (PI&R) inspection, the inspectors identified that IRs were not initiated as required per Exelon procedure PI-AA-120, CAP, for multiple out-of-calibration instruments that had been classified by Exelon as Single Point Vulnerabilities. (See NRC Inspection Report 05000277/278/2015008, Section 4OA2.1)

The inspectors assessed Exelons problem identification threshold, ACE, and the prioritization and timeliness of Exelons corrective actions to determine whether Exelon was appropriately identifying, characterizing, and correcting problems associated with this issue and whether the planned or completed corrective actions were appropriate.

The inspectors compared the actions taken to the requirements of Exelons CAP and 10 CFR 50, Appendix B. In addition, the inspectors reviewed subsequent IRs, reviewed instrument calibration data sheets, and interviewed maintenance I&C personnel to assess the effectiveness of the implemented corrective actions.

b. Findings and Observations

No findings were identified.

On May 22, 2015, Exelon performed an ACE to address the PD, and as such, an EOC review was performed. As part of the EOC review, a random sampling of WOs were reviewed by the instrumentation & control (I&C) department beyond the scope of the NRC PI&R inspection. Additional out-of-calibration instruments were identified by I&C without required IRs being initiated. Exelon indicated in their ACE that a potential behavior gap existed within the I&C department for generating IRs. Exelon identified through interviews that confusion existed to what were the IR initiation requirements for an out-of-calibration instrument. A briefing sheet had been previously created by I&C supervision to guide I&C technicians to initiate IRs for out-of-calibration instruments, however, the ACE concluded that communication within the maintenance department was less than adequate to ensure IRs were being generated. Corrective actions included supervisor stand downs with their respective I&C teams to disseminate the importance of IR initiation, including required sign-in sheets to be utilized to document attendance for all stand down meetings. A check-in assessment was also completed on August 29, 2015, which ensured all IRs were being generated for out-of-calibration instruments, and maintenance department managers and supervisors reinforced compliance with Exelon procedure ER-AA-520, Instrument Performance Trending.

The inspectors reviewed Exelons corrective actions and performed an additional sampling of out-of-calibration data sheets following these corrective actions, and did not identify any gaps within the past year. The inspectors determined that the I&C department was appropriately identifying and documenting deficient conditions in the CAP in accordance with PI-AA-120. However, the inspectors identified similar CAP implementation concerns in the electrical maintenance department and that opportunities for cross-disciplined learnings were missed concerning initiating IRs for conditions required by PI-AA-120. The inspectors concern was documented in the CAP as IR 2711781 and the inspectors determined that the issue was minor.

4OA3 Follow-Up of Events and Notices of Enforcement Discretion

Plant Events

a. Inspection Scope

For the plant event listed below, the inspectors reviewed and/or observed plant parameters, reviewed personnel performance, and evaluated performance of mitigating systems. The inspectors communicated the plant events to appropriate regional personnel, and compared the event details with criteria contained in IMC 0309, Reactive Inspection Decision Basis for Reactors, for consideration of potential reactive inspection activities. As applicable, the inspectors verified that Exelon made appropriate emergency classification assessments and properly reported the event in accordance with 10 CFR Parts 50.72 and 50.73. The inspectors reviewed Exelons follow-up actions related to the events to assure that Exelon implemented appropriate corrective actions commensurate with their safety significance.

• Unit 2 C RFP emergent trip due to erratic operation, and recirculation run back to 53 percent RTP on May 27, 2016

b. Findings

Introduction.

A self-revealing finding (FIN) of very low safety significance (Green) was identified for Exelons failure to maintain the Unit 2 C RFP Woodward controller secondary power supply in accordance with PES-S-002, Exelons Shelf life Program.

Specifically, on May 27, 2016, the Unit 2 C RFP experienced speed oscillations due to an age-related failure of the Woodward controller secondary power supply which resulted in an automatic recirculation runback to 53 percent RTP. The power supply contained an electrolytic capacitor that had exceeded its shelf life per PES-S-002.

Description.

PB Unit 2 has three turbine-driven RFPs. The RFPs are part of the feedwater system, which purifies and preheats condensed steam from the main condenser before returning it to the reactor vessel. The RFPs are operated by a control system, consisting of two control loops: a digital feedwater control system and Woodward 501 controller. The digital feedwater control system monitors reactor water level and sends a demand signal to the Woodward 501 controller, which then operates an electro-hydraulic actuator that is mechanically linked to an operating cylinder. This operating cylinder controls steam flow to the RFP turbine, thereby, controlling the flowrate of water pumped through the RFPs.

On May 27, 2016, Unit 2 operators observed an immediate step change to zero flow from the C RFP. The loss of C RFP flow caused reactor water level to decrease to 17 inches, resulting in a 45 percent recirculation pump runback and power decrease to 53 percent RTP. Following the initial transient, the C RFP flow rapidly increased resulting in a rise in reactor vessel level to 33 inches, 10 inches above the nominal set point. The C RFP flow oscillated back to zero flow, causing reactor water level to trend downwards. Operators recognized the erratic behavior of the oscillations and emergency stopped the Unit 2 C RFP.

Exelon determined through troubleshooting that the C RFPs Woodward controller had an overheated power supply. Further analysis of the C RFPs Woodward controller power supply identified the cause to be an age-related failure of an electrolytic capacitor installed within the Woodward controller secondary power supply. The secondary power supply had been replaced in June 2015 with a power supply that been stored in the warehouse for 18 years prior to installation.

Exelon performed an ACE and determined that back in May 1997, Exelon assigned the secondary power supply a defined shelf life, but incorrectly coded the component in their work management system without specifying an expiration date. In August 1999, Exelon created their current shelf life program, PES-S-002, and performed a review of in-stock warehouse parts to validate compliance with the program requirements. However, due to the incorrect expiration date entry, the Woodward secondary power supply was never maintained in accordance with PES-S-002 and, as a result, the power supply experienced an age-related failure, causing RFP oscillations and an unplanned Unit 2 down power to 53 percent RTP.

Exelons Shelf Life Program states that any items containing aluminum electrolytic capacitors are to have a maximum 10-year shelf life. The Unit 2 C RFP Woodward controller secondary power supply contains aluminum electrolytic capacitors and, therefore, should have been prescribed a maximum 10-year shelf life in compliance with PES-S-002. Because the secondary power supply was not properly tracked in Exelons Shelf Life Program, the power supply was not sent out for refurbishment when it exceeded its 10-year shelf life. This issue was entered into Exelons CAP under IR 02691322. Exelons corrective actions included replacement of the faulted power supply and performed an EOC review of proper expiration date entry for shelf life program components.

Analysis.

Exelons failure to maintain the Unit 2 C RFP Woodward controller secondary power supply, in accordance with PES-S-002, was a PD that was within their ability to foresee and correct and should have been prevented. The finding was more than minor because it was associated with the equipment performance attribute of the initiating events cornerstone and affected the cornerstones objective of limiting the likelihood of events that upset plant stability during power operations.

The inspectors evaluated the finding in accordance with Exhibit 1 of IMC 0609, Appendix A, SDP for Findings At-Power, and determined the finding was of very low safety significance (Green) because it did not cause a reactor trip, and the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition. The inspectors determined that no crosscutting aspect was applicable to this finding because the PD was not indicative of current performance. The PD occurred between 1997 and 1999 when the expiration date was incorrectly coded in Exelons work management process in accordance with PES-S-002.

Enforcement.

The finding does not involve enforcement action because the inspectors did not identify a violation of regulatory requirements associated with this finding.

Because the finding does not involve a violation of regulatory requirements and has very low safety significance, it is identified as a Finding. (FIN 05000277/2016003-01, Reactor Feed Pump Controller Power Supply Shelf Life Not Maintained)

4OA6 Meetings, Including Exit

Quarterly Resident

Exit Meeting Summary

On October 14, 2016, the inspectors presented the inspection results to Mr. Michael Massaro, Peach Bottom, Site Vice President and other members of Exelons staff. The inspectors verified that no proprietary information was retained by the inspectors or documented in this report.

ATTACHMENT:

SUPPLEMENTARY INFORMATION

KEY POINTS OF CONTACT

Exelon Generation Company Personnel

M. Massaro, Site Vice President

P. Navin, Plant Manager

J. Armstrong, Regulatory Assurance Manager

P. Breidenbaugh, Maintenance Director

D. Dullum, Regulatory Assurance Engineer

J. Fogarty, Nuclear Steam Supply Systems Manager

D. Henry, Engineering Director

B. Holmes, Radiation Protection Manager

P. Kester, Engineer

J. Koester, Fire Marshall

J. Lucas, Engineer

B. Miller, Engineer

M. Retzer, Systems Engineering Senior Manager

M. Rector, Engineering Response Team Manager

D. Turek, Operations Director

M. Weidman, Work Management Director

C. Weichler, Manager of Operations Support and Services

LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED

Opened/Closed

05000277/2016003-01 FIN Reactor Feed Pump Controller Power Supply Shelf Life Not Maintained (Section 4OA3)