IR 05000278/2017008

Problem Identification and Resolution Inspection Report 050002277/2017008 and 05000278/2017008

ML17132A140
Person / Time
Site:	Peach Bottom
Issue date:	05/11/2017
From:	David Kern Reactor Projects Region 1 Branch 4
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Schroeder D
References
IR 2017008
Download: ML17132A140 (22)

Text

May 11, 2017

SUBJECT:

PEACH BOTTOM ATOMIC POWER STATION - PROBLEM IDENTIFICATION AND RESOLUTION INSPECTION REPORT 05000277/2017008 AND 05000278/2017008

Dear Mr. Hanson:

On March 31, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed a problem identification and resolution inspection at the Peach Bottom Atomic Power Station (PB), Units 2 and 3. The NRC inspection team discussed the results of this inspection with Mr. Matt Herr, Plant Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.

The NRC inspection team reviewed the stations corrective action program and the stations implementation of the program to evaluate its effectiveness in identifying, prioritizing, evaluating, and correcting problems, and to confirm that the station was complying with NRCs regulations and licensee standards for corrective action programs. Based on the samples reviewed, the team determined that your staffs performance in each of these areas adequately supported nuclear safety.

The team also evaluated the stations processes for use of industry and NRC operating experience information and the effectiveness of the stations audits and self-assessments.

Based on the samples reviewed, the team determined that your staffs performance in each of these areas adequately supported nuclear safety.

Finally, the team reviewed the stations programs to establish and maintain a safety-conscious work environment, and interviewed station personnel to evaluate the effectiveness of these programs. Based on the teams observations and the results of these interviews, the team found no evidence of challenges to your organizations safety-conscious work environment.

Your employees appeared willing to raise nuclear safety concerns through at least one of the several means available.

NRC inspectors documented two findings of very low safety significance (Green) in this report.

Each of these findings involved a violation of NRCs requirements. The NRC is treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2.a of the Enforcement Policy. If you contest the violations or significance of these NCVs, 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 I; the Director, Office of Enforcement; and the NRCs Resident Inspector at Peach Bottom. In addition, if you disagree with a cross-cutting aspect assignment, 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 NRCs 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 NRCs Public Document Room in accordance with 10 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 05000277/2017008 and 05000278/2017008 w/Attachment:

Supplementary Information

REGION I==

Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-5656 Report Nos. 05000277/2017008 and 05000278/2017008 Licensee: Exelon Generation Company, LLC Facility: Peach Bottom Atomic Power Station, Units 2 and 3 Location: Delta, Pennsylvania Dates: March 13-17, 2017 March 27-31, 2017 Team Leader: David Kern, Senior Reactor Inspector Inspectors: Justin Heinly, Senior Resident Inspector Ross Telson, Reactor Operations Engineer Sarah Elkhiamy, Project Engineer Approved by: Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure

SUMMARY

IR 05000277/2017008 and 05000278/2017008; 3/13 - 3/31/2017; Peach Bottom

Atomic Power Station Units 2 and 3; Biennial Baseline Inspection of Problem Identification and Resolution. The inspectors identified two findings in the area of effectiveness of corrective actions.

This NRC team inspection was performed by one NRC headquarters inspector, two regional inspectors, and one resident inspector. The inspectors identified two findings of very low safety significance (Green) during this inspection and classified these findings as non-cited violations.

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, dated April 29, 2015. Cross-cutting aspects are determined using IMC 0310, Components Within Cross-Cutting Areas, dated December 4, 2014. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated July 7, 2016. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 6.

Problem Identification and Resolution The inspectors concluded that Exelon was generally effective in identifying, evaluating, and resolving problems. Exelon personnel identified problems, entered them into the corrective action program at a low threshold, and prioritized issues commensurate with their safety significance. Exelon appropriately screened issues for operability and reportability, and performed causal analyses that appropriately considered extent-of-condition, generic issues, and previous occurrences. The inspectors also determined that Exelon usually implemented corrective actions to address the problems identified in the corrective action program in a timely manner. However, the inspectors identified two violations of NRC requirements, both in the area of effectiveness of corrective actions.

The inspectors concluded that Exelon adequately identified, reviewed, and applied relevant industry operating experience to Peach Bottom operations. In addition, based on those items selected for review, the inspectors determined that Exelons self-assessments and audits were thorough.

Based on the interviews the inspectors conducted over the course of the inspection, observations of plant activities, and reviews of individual corrective action program and employee concerns program issues, the inspectors did not identify any indications that site personnel were unwilling to raise safety issues.

Cornerstone: Mitigating Systems

Green.

The inspectors identified a non-cited violation of 10 CFR 50 Appendix B,

Criterion XVI, Corrective Action, because Exelon did not implement corrective actions in a timely manner to correct a condition adverse to quality on the 2C core spray motor.

Specifically, Exelon did not perform appropriate corrective actions to evaluate and address an increasing motor bearing vibration trend that had existed for over ten years.

Consequently, motor vibration reached the fault level established in Exelons vibration analysis procedure.

The finding was more than minor, because it was associated with the equipment performance attribute of the Mitigating Systems cornerstone and adversely impacted the cornerstone objective to ensure the reliability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage).

In accordance with IMC 0609.04, Initial Characterization of Findings, dated October 7, 2016, and Exhibit 1 of IMC 0609, Appendix A, The SDP for Findings At-Power, dated June 19, 2012, the inspectors determined this finding was of very low safety significance because the performance deficiency did not impact the design or qualification of the component, did not result in a loss of system function, did not result in the loss of function of a train greater than its Tech Spec allowed outage time, and did not represent an actual loss of function for a high safety significant component in accordance with Exelons maintenance rule program. The inspectors determined the finding had a cross-cutting aspect in the area of Problem Identification and Resolution, Resolution, because Exelon did not take effective corrective actions in a timely manner commensurate with the safety significance of the issue.

Specifically, corrective actions to address the elevated vibrations on the 2C core spray motor were not implemented before motor vibration reached the fault level and adversely impacted the long-term reliability of the motor. [P.3] [Section 4OA2.1.c (1)]

Cornerstone: Barrier Integrity

Green.

The inspectors identified a self-revealing non-cited violation of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, because Exelon did not promptly implement corrective actions to address a condition adverse to quality on two containment isolation valves. Specifically, drywell air sampling valves SV-3-7D-3671A and SV-3-7D-3671D failed to perform their primary containment isolation function on March 15 and September 26, 2016, respectively, as a result of untimely corrective actions to address elevated leakage. The valve internals were repaired, declared operable, and the issue was entered into the corrective action program (IR 3990490).

The finding was more than minor, because it was associated with the barrier performance attribute of the Barrier Integrity cornerstone and adversely affected the cornerstones objective to provide reasonable assurance that the containment design barrier protect the public from radionuclide releases caused by accidents or events. In accordance with IMC 0609.04, Initial Characterization of Findings, dated October 7, 2016, and Exhibit 1 of IMC 0609, Appendix A, The SDP for Findings At-Power, dated June 19, 2012, the inspectors determined this finding was of very low safety significance, because the finding did not result in an actual open pathway in the physical integrity of the reactor containment or involve an actual reduction in the function of hydrogen igniters in the reactor containment. The inspectors determined this finding had a cross-cutting aspect in the area of Problem Identification and Resolution, Resolution, because Exelon did not perform effective corrective actions in a timely manner commensurate with the safety significance of the issue. Specifically, corrective actions to address a CAQ on SV-3-7D-3671A and SV-3-7D-3671D were delayed which resulted in the valves failing their LLRT and being declared inoperable. [P.3] [Section 4OA2.1.c (2)]

REPORT DETAILS

4OA2 Problem Identification and Resolution

This inspection constitutes one biennial sample of problem identification and resolution as defined by Inspection Procedure 71152. All documents reviewed during this inspection are listed in the Attachment to this report.

.1 Assessment of Corrective Action Program Effectiveness

a. Inspection Scope

The inspectors reviewed the procedures that described Exelons corrective action program at Peach Bottom. To assess the effectiveness of the corrective action program, the inspectors reviewed performance in three primary areas: problem identification, prioritization and evaluation of issues, and corrective action implementation. The inspectors compared performance in these areas to the requirements and standards contained in 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, and Exelon procedure PI-AA-125, Corrective Action Program (CAP) Procedure. For each of these areas, the inspectors considered risk insights from the stations risk analysis and reviewed CAP issue reports selected across the seven cornerstones of safety in the NRCs Reactor Oversight Process. Additionally, the inspectors attended multiple Station Ownership Committee and Management Review Committee meetings. The inspectors selected items from the following functional areas for review: engineering, operations, maintenance, emergency preparedness, radiation protection, physical security, Maintenance Rule, and oversight programs.

(1) Effectiveness of Problem Identification In addition to the items described above, the inspectors reviewed system health reports, a sample of completed corrective and preventative maintenance work orders, completed surveillance test procedures, operator logs, and periodic trend reports. The inspectors also performed field walkdowns of various systems in both Units 2 and 3 and common areas, which included the high pressure coolant injection, core spray, residual heat removal, control rod drive, emergency service water, and high pressure service water systems, vital 4 kV and 480 volt electrical buses, remote shutdown control panels, and the central alarm station. Additionally, the inspectors reviewed a sample of issue reports written to document issues identified through internal self-assessments, audits, emergency preparedness drills, and the operating experience program. The inspectors completed this review to verify that Exelon entered conditions adverse to quality into their CAP, as appropriate.

(2) Effectiveness of Prioritization and Evaluation of Issues The inspectors reviewed the evaluation and prioritization of a sample of issue reports issued since the last NRC biennial problem identification and resolution inspection completed in June 2015. The inspectors also reviewed issue reports that were assigned lower levels of significance that did not include formal cause evaluations to ensure that they were properly classified. The inspectors review included the appropriateness of the assigned significance, the scope and depth of causal analysis, and resolution timeliness.

The inspectors assessed whether the evaluations identified likely causes for the issues and developed appropriate corrective actions to address the identified causes.

Further, the inspectors reviewed equipment operability determinations, reportability assessments, and extent-of-condition reviews for selected problems to verify these processes adequately addressed equipment operability, reporting of issues to the NRC, and the extent of the issues.

(3) Effectiveness of Corrective Actions The inspectors reviewed Exelons completed corrective actions through documentation review and, in some cases, field walkdowns to determine whether the actions addressed the identified causes of the problems. The inspectors also reviewed issue reports for adverse trends and repetitive problems to determine whether corrective actions were effective in addressing the broader issues. The inspectors reviewed Exelons timeliness in implementing corrective actions and effectiveness in precluding recurrence for significant conditions adverse to quality. The inspectors also reviewed a sample of CAP issue reports associated with selected non-cited violations and findings to verify that Exelon personnel properly evaluated and resolved these issues. In addition, the inspectors expanded the corrective action review to five years to evaluate Exelons actions related to the Unit 2 high pressure coolant injection system and the containment isolation valve local leak rate test program.

b. Assessment

(1) Effectiveness of Problem Identification Based on the selected samples, plant walkdowns, and interviews of site personnel in multiple functional areas, the inspectors determined that Exelon identified problems and entered them into the CAP at a low threshold. Exelons staff at Peach Bottom initiated approximately 24,000 issue reports between January 2015 and January 2017. The inspectors observed supervisors at the Station Ownership Committee meetings appropriately questioning and challenging issue reports to ensure clarification of the issues. Based on the samples reviewed, the inspectors determined that overall Exelon trended equipment and programmatic issues, and appropriately identified problems in issue reports. The inspectors verified that conditions adverse to quality identified through this review were entered into the CAP as appropriate. The inspectors also concluded that personnel were identifying trends at low levels.

Additionally, the inspectors identified two minor observations regarding effectiveness of problem identification, which had not been entered into the CAP.

Informal Markings Used for Equipment Configuration Control Informal ink markings were added to the 2B core spray pump room cooler controller and the reactor water cleanup demineralizer temperature gage as operator aides to help maintain equipment configuration. Station procedures for use of operator aides and equipment labeling did not permit use of informal markings to control equipment position.

Service Water Expansion Joints Inspection Interval Deviation The inspectors identified that service water rubber expansion joints were inspected at a 6 year interval instead of a 2 year interval as specified by Rubber Expansion Joint and Rubber Hose Preventative Maintenance Template, Revision 0. No technical justification had been developed to support inspecting the expansion joints less often than specified. The inspectors walked down the expansion joints and no significant signs of degradation were evident.

The inspectors determined both issues were performance deficiencies, because Exelon did not identify the conditions adverse to quality and enter them into the CAP. Following discussion with the inspectors Exelon promptly entered the issues into the CAP (issue reports 3990400 and 3992060), determined neither issue adversely effected availability, reliability, or operability of the core spray or service water systems, and initiated action to correct the deficiencies. The inspectors independently screened both performance deficiencies in accordance with IMC 0612, Appendix B, Issue Screening, and determined that the issues were of minor significance and, therefore, were not subject to enforcement action in accordance with the NRCs Enforcement Policy.

(2) Effectiveness of Prioritization and Evaluation of Issues The inspectors determined that, in general, Exelon appropriately prioritized and evaluated issues commensurate with the safety significance of the identified problem.

Exelon screened issue reports (IRs) for operability and reportability, categorized issue reports by significance, and assigned actions to the appropriate department for evaluation and resolution. The issue report screening process considered human performance issues, radiological safety concerns, repetitiveness, adverse trends, and potential impact on the safety conscious work environment.

Based on the sample of issue reports reviewed, the inspectors determined the guidance provided by Exelon CAP implementing procedures was sufficient to support consistent categorization of issues. Operability and reportability determinations were generally performed when conditions warranted and in most cases, the evaluations supported the conclusion. Causal analyses appropriately considered the extent-of-condition or problem, generic issues, and previous occurrences of the issue.

However, the inspectors identified several recent issues associated with misclassification of CAP assignments as enhancement assignments (ACITs) instead of corrective action assignments (CAs) for conditions adverse to quality as specified by Exelon procedures. The CAP process permits an ACIT assignment to be closed without management review. A corrective action assignment type would require further management review prior to closure. As a result resolution of issues have not been timely in some instances. The inspectors discussed this observation with the Peach Bottom CAP coordinator and other plant staff. Exelon acknowledged the concern and initiated action to evaluate and address the issue through the CAP (IR 3992162).

Examples include the two findings documented in section 4OA2.1 of this report and two findings documented in recent NRC inspection reports (NCV 05000277(278) /2016002-02 and NCV 05000277/2016004-01). The inspectors also identified several additional examples of untimely resolution of conditions adverse to quality as described below:

Unverified Design Basis Assumptions for Internal Flood Mitigation Safety-related high pressure service water (HPSW) and emergency service water (ESW) pumps are located in two rooms that share a common drain system within the pump structure. PM-1048, Internal Flood Protection Design Basis for HPSW/ESW Structure, Revision 1, design input 3.4 states, HPSW/ESW pump room level alarm instruments LS-4155 and LS-5155 have a setpoint 6 inches above floor elevation. In 2014, NRC inspectors questioned the adequacy of pump structure level instrument and alarm testing to validate design calculation assumptions for operator response time to mitigate internal pump room flooding.

Issue report 1636300 was initiated to address this concern.

During this inspection, the inspectors noted station personnel had assigned an ACIT (enhancement) assignment type and closed IR 1636300 with no action taken.

No maintenance or suitable testing was performed to verify the level alarm setpoint design bases assumption. The inspectors determined the failure to promptly correct this condition adverse to quality was a performance deficiency. The inspectors independently screened the performance deficiency in accordance with IMC 0612, Appendix B, Issue Screening, and determined the issue was of minor significance and, therefore, was not subject to enforcement action in accordance with the NRCs Enforcement Policy. Specifically, station personnel tested the level instrument alarms and determined there was sufficient margin in the design calculation to ensure adequate operator response time to mitigate pump structure internal flooding. Exelon documented this issue in the CAP (IRs 3990496; 3990632; 3990633; 3990929; 3991479 and 3991882).

• Untimely Corrective Action to Address Degraded Feedwater Check Valve Performance On October 24, 2014, IR 2402909 documented a failure of two containment isolation check valves (CHK-2-06-28A and CHK-2-06-96A) in a single penetration which resulted in the loss of the containment safety function. The condition was documented in the Peach Bottom Unit 2 Licensee Event Report 2014-003 which was reviewed and closed in NRC Inspection Report No. 05000277(278)/2015002.

Exelon determined the cause of the check valve failures was internal wear due to being in service beyond their preventive maintenance (PM) periodicity of 16 years.

Exelon implemented a corrective action to reinstitute the 16 year PM frequency to ensure valve wear was identified and corrected prior to valve failure. The extent-of-condition population consisted of six other feedwater check valves. Corrective actions included scheduling the oldest of the valves first for the overhaul PM.

The inspectors reviewed the prioritization and implementation of the corrective actions associated with IR 2402909 corrective actions. The inspectors determined station personnel subsequently deferred the scheduled PM on Unit 3 feedwater check valve CHK-3-06-28B beyond its originally scheduled corrective action due date, which resulted in the valve being in service beyond its 16 year PM frequency.

The inspectors determined the untimely implementation of the corrective actions to perform the PM was a performance deficiency. The inspectors independently screened the performance deficiency in accordance with IMC 0612, Appendix B, Issue Screening, and determined the issue was of minor significance and, therefore, were not subject to enforcement action in accordance with the NRCs Enforcement Policy. Specifically, CHK-3-06-28B passed its latest LLRT surveillance test and had been in service for less time than the valves that failed in 2014. Exelon documented the issue in the CAP (IR 3991450).

Inconsistent Assignment of Corrective Action to address Severity Level 3 Issue Reports Exelon performed a CAP program self-assessment in early 2017. The self-assessment identified that station personnel did not consistently assign CA assignment types or develop causal statements for significance level 3 IRs as required by CAP program procedures. The inspectors independently screened the performance deficiency in accordance with IMC 0612, Appendix B, Issue Screening, and determined the issue was of minor significance and, therefore, were not subject to enforcement action in accordance with the NRCs Enforcement Policy.

Specifically, the self-assessment did not identify any specific safety issues that resulted from this deficient implementation of the CAP procedure. Exelon entered this self-identified concern into the CAP (IR 3974366).

(3) Effectiveness of Corrective Actions The inspectors concluded that corrective actions for identified deficiencies were typically timely, focused, and adequately implemented. For significant conditions adverse to quality, Exelon identified actions to prevent recurrence. Corrective actions to address a trend of human performance errors were effective and primarily consisted of revising their Management Review Meeting (MRM) crew performance assessment model and extending the model for use by the Maintenance, Chemistry, and Radiation Protection Departments. The inspectors concluded that corrective actions to address the sample of NRC non-cited violations and findings since the last problem identification and resolution inspection were usually timely and effective.

Additionally, the inspectors identified two examples of more than minor significance where Exelon was not effective in implementing timely corrective actions. These findings are documented in Section 4OA2.1.c.

b. Findings

(1) Untimely Corrective Actions to Address 2C Core Spray Motor Elevated Vibrations

Introduction.

The inspectors identified a Green non-cited violation of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, because Exelon did not implement corrective actions in a timely manner to correct a condition adverse to quality on the 2C core spray motor. Specifically, Exelon did not perform appropriate corrective actions to evaluate and address an increasing motor bearing vibration trend that had existed for over ten years. Consequently, 2C core spray motor vibration reached the fault level established in Exelons vibration analysis procedure.

Description.

The core spray system is a safety-related low pressure injection system that maintains the reactor core covered and cool during a loss of coolant accident (LOCA). Furthermore, the system provides a means for long term core cooling after a LOCA for up to 100 days. The system maintains two independent subsystems and each subsystem contains two pumps. Core spray pumps are operated and pump vibration measured periodically as required by Technical Specifications. Motor bearing vibration readings are measured less frequently (based on technician availability) as a good practice to maintain equipment reliability. The Component Maintenance Optimization department evaluates motor vibration as required by station procedures. Exelon procedure, MA-AA-716-230-1002, Vibration Analysis/

Acceptance Guideline, Revision 4, establishes alert and fault vibration criteria to ensure action is taken prior to damage to the equipment.

The inspectors reviewed previous IRs associated with the core spray system and identified that the 2C core spray motor exhibited a long-term degrading vibration trend in its upper motor bearings and that the long-standing issue had not been properly resolved. On July 2, 2009, IR 938338 was written to document and evaluate a rising 2C core spray motor vibration trend. The issue report directed that corrective action be implemented within one year, based upon the trend results exceeding the alert limit. The IR created an action to develop a troubleshooting plan and opened a tracking AR assignment used to track the issue. The troubleshooting plan was developed. However, the assignment was classified as an enhancement (ACIT) in lieu of a corrective action assignment.

The ACIT assignment was then closed without implementing the troubleshooting plan and no actions were tied to the open AR. On July 30, 2015, IR 2534870 was written to document the continued degrading trend and that the vibration level was about to exceed the fault limit. Engineers closed this IR to the open AR from 2009, and no further actions were performed.

The inspectors reviewed vibration data for the 2C core spray motor and identified that the vibration in the upper motor bearing had not been recorded since 2015.

Procedure MA-AA-716-230-1002 defines the fault limit as a vibratory state where corrective actions should be taken immediately or the machine should be shut down.

Operation of equipment at or above this level of vibration is likely to result in severe degradation and damage to the equipment. The inspectors expressed concern that given the current adverse trend and the absence of data for the past two years, it was likely that the motor upper bearing vibration had exceeded the fault limit and corrective actions should have been performed.

Engineers initiated IR 3990487 to evaluate whether the motor would meet its 100 day mission time. Motor oil analysis, thermography, and motor operating characteristics were trended and evaluated and no significant degraded condition was identified.

Station personnel concluded the elevated vibration readings were caused by resonance, the vibrations did not indicate a degraded motor bearing condition, and the 2C core spray motor remained operable. The inspectors reviewed the proposed actions and determined that the degradation was a long term concern and the near term planned actions were commensurate with the safety significance of the issue.

An extent-of-condition review did not identify any additional safety related components above the fault limit. Additionally, Exelon expedited implementation of the troubleshooting plan and repairs or modifications to the motor to reduce the vibration issue.

Analysis.

The inspectors identified that failure to perform timely corrective actions to address a degrading vibration trend on the 2C core spray motor which resulted in the vibration reaching the fault limit was a performance deficiency that was within Exelons ability to foresee and correct. The finding was more than minor, because it was associated with the equipment performance attribute of the Mitigating Systems cornerstone and adversely impacted the cornerstone objective to ensure the reliability of systems that respond to initiating events to prevent undesirable consequences (i.e.,

core damage). Specifically, the reliability of the 2C core spray motor was adversely impacted due to the untimely corrective actions to address the elevated vibrations.

The inspectors evaluated the significance of this finding using IMC 0609, Appendix A, The Significance Determination Process for Findings at Power, Exhibit 2 - Mitigating Systems Screening Questions. The inspectors determined this finding was of very low safety significance (Green) because the finding did not impact the design or qualification of the component, did not result in a loss of system function, did not result in the loss of function of a train greater than its Technical Specification allowed outage time, and did not represent an actual loss of function for a high safety significant component in accordance with Exelons maintenance rule program. The inspectors determined the finding had a cross-cutting aspect in the area of Problem Identification and Resolution, Resolution, because Exelon did not take effective corrective actions in a timely manner commensurate with the safety significance of the issue.

Specifically, corrective actions to address the elevated vibrations on the 2C core spray motor were not implemented before motor vibration reached the fault level. [P.3]

Enforcement.

10 CFR 50, Appendix B, Criterion XVI, Corrective Action, requires that measure shall be established to assure conditions adverse to quality are promptly identified and corrected. Contrary to the above, since July 2, 2009, Exelon did not assure that a condition adverse to quality associated with the 2C core spray motor was corrected commensurate with the safety significance. Specifically, Exelon did not take timely corrective actions to address the long term degrading trend in 2C core spray upper motor vibrations, which resulted in the motor reaching its fault value. Because this violation was of very low safety significance (Green), Exelon performed a prompt determination of operability, and the issue was entered into the corrective action program for resolution (IR 3990487), this violation is being treated as an NCV, consistent with section 2.3.2.a of the NRC Enforcement Policy. (NCV 05000277/2017008-01, Untimely Corrective Actions to Address 2C Core Spray Motor Elevated Vibrations)

(2) Untimely Corrective Actions to Address Elevated Primary Containment Isolation Valve Leakage

Introduction.

The inspectors identified a Green self-revealing non-cited violation of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, because Exelon did not promptly implement corrective actions to address a condition adverse to quality on two containment isolation valves. Specifically, drywell air sampling valves SV-3-7D-3671A and SV-3-7D-3671D failed to perform their primary containment isolation function on March 15 and September 26, 2016, respectively, as a result of untimely corrective actions to address elevated leakage. The valve internals were repaired, declared operable, and the issue was entered into the corrective action program (IR 3990490).

Description.

A primary function of the containment atmosphere control/dilution (CAC/CAD) system is to sample the containment atmosphere to determine combustible gas concentrations and to monitor radiation levels during normal power operations. SV-3-7D-3671A and SV-3-7D-3671D are solenoid operated valves located in the sample line from the drywell to the CAC/CAD analyzer. The valves normally remain open to support the sampling function. However, they have a safety function to close to maintain primary containment isolation. These valves are local leak rate tested (LLRT) to ensure they maintain their leak tightness requirements for containment operability.

On February 10, 2015, the internal valve components for SV-3-7D-3671A were replaced in accordance with its preventive maintenance schedule. The post-maintenance testing LLRT identified that the valve exhibited elevated leakage and IR 2447885 was written to expedite valve repair. The valve leak rate during the LLRT met operability requirements. However, the elevated leakage indicated that a CAQ existed and the valve internals needed to be repaired prior to the next surveillance test. The CAP directed a corrective maintenance work order be performed. However; it did not clearly identify the issue was a CAQ that required timely corrective action prior to the next periodic LLRT. As a result work management bundled the corrective maintenance with planned valve replacement in April 2016. No assessment of the valves capability to perform its isolation safety function until that date was performed.

Subsequently, on March 15, 2016, the valve failed an LLRT test and was declared inoperable (IR 2640532).

Station personnel determined the corrective actions to address the SV-3-7D-3671A CAQ were inappropriately delayed, which resulted in the valve failure. The stations extent-of-condition review identified three additional degraded valves whose corrective maintenance work orders had not been scheduled commensurate with the safety significance. The three valves were promptly tested and an additional LLRT failure was identified on SV-3-7D-3671D (IR 2720237), which had an open work order to address elevated leakage documented in the CAP since June 13, 2014. The cause of the LLRT failures was determined to be looseness of the valve internals as well as the presence of debris in the CAC/CAD piping system.

Technicians performed corrective maintenance on SV-3-7D-3671A and SV-3-7D-3671D valve internals and the valves were declared operable following a successful LLRT. The impact of the debris in the CAC/CAD system created a long term system and valve health concern. Additional evaluation and long term corrective actions to address the source of debris in the lines were documented in IRs 3987716 and 3990490. The inspectors determined the associated troubleshooting and corrective actions were scheduled commensurate with the safety significance.

Analysis.

The inspectors determined that failure to promptly correct a CAQ associated with degraded primary containment isolation valves SV-3-7D-3671A and SV-3-7D-3671D, was a performance deficiency that was within Exelons ability to foresee and correct. The finding was more than minor, because it was associated with the barrier performance attribute of the Barrier Integrity cornerstone and adversely affected the cornerstones objective to provide reasonable assurance that the containment design barrier protect the public from radionuclide releases caused by accidents or events. Specifically, SV-3-7D-3671A and SV-3-7D-3671D failed to perform their primary containment isolation function as a result of untimely corrective actions. The inspectors evaluated the significance of this finding using IMC 0609, Appendix A, The Significance Determination Process for Findings at Power, Exhibit 3-Barrier Integrity Screening Questions. The inspectors determined this finding was of very low safety significance (Green) because the finding did not result in an actual open pathway in the physical integrity of the reactor containment or involve an actual reduction in the function of hydrogen igniters in the reactor containment.

The inspectors determined this finding had a cross-cutting aspect in the area of Problem Identification and Resolution, Resolution, because Exelon did not take effective corrective actions in a timely manner commensurate with the safety significance of the issue. Specifically, corrective actions to address a CAQ on SV-3-7D-3671A and SV-3-7D-3671D were incorrectly delayed, which resulted in the valves failing their LLRT and being declared inoperable. [P.3]

Enforcement.

10 CFR 50, Appendix B, Criterion XVI, Corrective Action, requires that measures shall be established to assure conditions adverse to quality are promptly identified and corrected. Contrary to this requirement, from June 13, 2014 until March 15, 2016, Exelon did not assure CAQs associated with primary containment isolation valves were promptly corrected commensurate with their safety significance.

Specifically, Exelon did not perform timely repair of SV-3-7D-3671A and SV-3-7D-3671D valve internals, which resulted in LLRT failure and declaring the valves inoperable. Corrective action included repair of the two inoperable valves, extent-of-condition evaluation, and review of the issues via the CAP.

Because this violation was of very low safety significance and was entered into the corrective action program for resolution (IR 3990490), this violation is being treated as an NCV, consistent with section 2.3.2.a of the NRC Enforcement Policy.

(NCV 05000278/2017008-02, Untimely Corrective Actions to Address Elevated Primary Containment Isolation Valve Leakage)

.2 Assessment of the Use of Operating Experience

a. Inspection Scope

The inspectors reviewed a sample of CAP issue reports associated with review of industry operating experience to determine whether Exelon appropriately evaluated the operating experience information for applicability to Peach Bottom and had taken appropriate actions, when warranted. The inspectors also reviewed evaluations of operating experience documents associated with a sample of NRC generic communications to ensure that Exelon adequately considered the underlying problems associated with the issues for resolution via their corrective action program. In addition, the inspectors observed various plant activities to determine if the station considered industry operating experience during the performance of routine and infrequently performed activities.

Assessment The inspectors determined that Exelon appropriately considered industry operating experience information for applicability, and used the information for corrective and preventive actions to identify and prevent similar issues when appropriate. The inspectors determined that operating experience was appropriately applied and lessons learned were communicated and incorporated into plant operations and procedures when applicable. The inspectors also observed that industry operating experience was routinely discussed and considered during the conduct of Plan-of-the-Day meetings and pre-job briefs.

b. Findings

No findings were identified.

.3 Assessment of Self-Assessments and Audits

a. Inspection Scope

The inspectors reviewed a sample of audits, including the most recent audit of the CAP, departmental self-assessments, and assessments performed by independent organizations. Inspectors performed these reviews to determine if Exelon entered problems identified through these assessments into the CAP, when appropriate, and whether Exelon initiated corrective actions to address identified deficiencies. The inspectors evaluated the effectiveness of the audits and assessments by comparing audit and assessment results against self-revealing and NRC-identified observations made during the inspection.

Assessment The inspectors concluded that self-assessments, audits, and other internal Exelon assessments were generally critical, thorough, and effective in identifying performance issues. The inspectors observed that Exelon personnel knowledgeable in the subject completed these audits and self-assessments in a methodical manner. Exelon completed these audits and self-assessments to a sufficient depth to identify issues which were then entered into the CAP for evaluation. In general, the station implemented corrective actions associated with the identified issues commensurate with their safety significance.

b. Findings

No findings were identified.

.4 Assessment of Safety Conscious Work Environment

a. Inspection Scope

During interviews with station personnel, the inspectors assessed the safety conscious work environment at Peach Bottom. Specifically, the inspectors interviewed personnel to determine whether they were hesitant to raise safety concerns to their management and/or the NRC. The inspectors also interviewed the station Employee Concern Program (ECP) coordinator to determine what actions are implemented to ensure employees were aware of the program and its availability with regards to raising safety concerns. The inspectors reviewed the ECP files to evaluate depth of issue investigation, and to ensure that Exelon entered issues into the corrective action program when appropriate.

Assessment During interviews, Peach Bottom staff expressed a willingness to use the corrective action program to identify plant issues and deficiencies and stated that they were willing to raise safety issues. The inspectors noted that no one interviewed stated that they personally experienced or were aware of a situation in which an individual had been retaliated against for raising a safety issue. All persons interviewed demonstrated an adequate knowledge of the corrective action program and the ECP. Based on these limited interviews and review of selected ECP files, the inspectors concluded that there was no evidence of an unacceptable safety conscious work environment and no significant challenges to the free flow of information.

b. Findings

No findings were identified.

4OA6 Meetings, Including Exit

On March 31, 2017, the inspectors presented the inspection results to Matt Herr, Plant Manager, and other members of the Peach Bottom 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

Licensee Personnel

M. Herr, Plant Manager

J. Armstrong, Regulatory Assurance Manager

P. Breidenbaugh, Maintenance Director

D. Dullum, Regulatory Assurance Engineer

M. Flynn, Corrective Action Program Manager

J. Fogarty, Nuclear Steam Supply Systems Manager

J. Glunt, Organizational Effectiveness Manager

S. Griffith, Security Supervisor

T. Haehle, Senior Design Engineer

D. Henry, Engineering Director

D. Hilt, Shift Operations Superintendent

R. Holmes, Radiation Protection Manager

P. Kester, Mechanical Design Engineer

M. Lefever, System Manager

P. Pasqual, Environmental Qualification Program Manager

D. Turek, Operations Director

M. Weidman, Work Management Director

NRC Personnel

D. Aird, (Acting) Resident Inspector

D. Schroeder, Chief, Reactor Projects Branch 4

LIST OF ITEMS OPENED, CLOSED, DISCUSSED AND UPDATED

Opened and Closed

05000277/2017008-01 NCV Untimely Corrective Actions to Address 2C Core Spray Motor Elevated Vibrations (Section 4OA2.1.c (1))

05000278/2017008-02 NCV Untimely Corrective Actions to Address Elevated Primary Containment Isolation Valve Leakage (Section 4OA2.1.c (2))