IR 05000387/2013010

IR 05000387-13-010 and 05000388-13-010; 7/29/2013 to 8/29/2013; PPL Susquehanna, LLC (Ppl); Susquehanna Steam Electric Station, Units 1 and 2; Component Design Bases Inspection

ML13275A074
Person / Time
Site:	Susquehanna
Issue date:	10/01/2013
From:	Paul Krohn Engineering Region 1 Branch 2
To:	Rausch T Susquehanna
References
IR-13-010
Download: ML13275A074 (32)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION ber 1, 2013

SUBJECT:

SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2 - NRC COMPONENT DESIGN BASES INSPECTION REPORT 05000387/2013010 AND 05000388/2013010

Dear Mr. Rausch:

On August 29, 2013, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Susquehanna Steam Electric Station (SSES), Units 1 and 2. The enclosed inspection report documents the inspection results, which were discussed, on August 29, 2013, with Mr. William Bishop, General Manager Maintenance, and other members of your staff.

The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.

In conducting the inspection, the team examined the adequacy of selected components and operator actions to mitigate postulated transients, initiating events, and design basis accidents.

The inspection involved field walkdowns, examination of selected procedures, calculations and records, and interviews with station personnel.

This report documents one NRC-identified finding which was of very low safety significance (Green). The finding was determined to involve a violation of NRC requirements. However, because of the very low safety significance of the violation and because it was entered into your correction action program, the NRC is treating the finding as a non-cited violation (NCV)

consistent with Section 2.3.2.a of the NRC Enforcement Policy. If you contest the NCV in this 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, D.C. 20555-0001, with copies to the Regional Administrator, Region I; the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555-0001; and the NRC Resident Inspector at the Susquehanna Steam Electric Station. In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390 of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for the public inspection in the NRC Public Docket Room or from the Publicly Available Records component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety Docket No. 50-387, 50-388 License No. NPF-14, NPF-22

Enclosure:

Inspection Report 05000387/2013010 and 05000388/2013010 w/Attachment: Supplemental Information

REGION I==

Docket No: 50-387; 50-388 License No: NPF-14; NPF-22 Report No: 05000387/2013010 and 05000388/2013010 Licensee: PPL Susquehanna, LLC (PPL)

Facility: Susquehanna Steam Electric Station, Units 1 and 2 Location: Berwick, PA Dates: July 29 to August 29, 2013 Inspectors: K. Mangan, Senior Reactor Inspector, Division of Reactor Safety (DRS), Team Leader G. Meyer, Senior Reactor Inspector, DRS M. Orr, Reactor Inspector, DRS J. Patel, Reactor Inspector, DRS C. Edwards, NRC Mechanical Contractor O. Mazzoni, NRC Electrical Contractor Approved by: Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety i Enclosure

SUMMARY OF FINDINGS

IR 05000387/2013010 and 05000388/2013010; 7/29/2013 - 8/29/2013; PPL Susquehanna,

LLC (PPL); Susquehanna Steam Electric Station, Units 1 and 2; Component Design Bases Inspection.

The report covers the Component Design Bases Inspection conducted by a team of four NRC inspectors and two NRC contractors. One finding of very low risk significance (Green) was identified; the finding was considered to be a non-cited violation. The significance of most findings is indicated by their color (Green, White, Yellow, Red) using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP). Findings for which the SDP does not apply may be Green or be assigned a severity level after NRC management review. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 4, dated December 2006.

Cornerstone: Mitigating Systems

Green.

The team identified a finding of very low safety significance (Green) involving a non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that PPL failed to verify or check the adequacy of the design of molded case circuit breakers (MCCB). The team reviewed PPL response to NRC Information Notice 93-64, Periodic Testing and Preventive Maintenance of Molded Case Circuit Breakers and determined that PPL had not included certain 125Vdc and 120Vac MCCBs in their evaluation.

Subsequently the team determined that PPL had not performed any maintenance or testing on these breakers since original construction. The team found that several 125Vdc breakers were credited as one of the two isolation devises required to ensure primary containment electrical penetrations are not damaged during overload or fault conditions on the circuit. The team concluded that PPL did not verify that these safety-related 125Vdc MCCBs would perform this safety function. PPL entered the issue into their corrective action program and performed an operability evaluation on the penetrations determining them to be operable but non-conforming because the second isolation device would perform the intended safety function. The team reviewed the evaluation and determined it to be reasonable.

The finding was determined to be more than minor because it was associated with the Barrier Integrity Containment Design Control and Configuration Control attribute and affected the cornerstones objective. Using the NRC IMC 0609, Significance Determination Process, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 3, Section B, the finding was determined to be of very low safety significance (Green). There was no crosscutting aspect assigned to the finding because it was not indicative of current performance. (Section 1R21.2.2.2)

Licensee-Identified Violations

None ii

REPORT DETAILS

1R21 Component Design Bases Inspection (IP 71111.21)

.1 Inspection Sample Selection Process

The team selected risk significant components for review using information contained in the Susquehanna Steam Electric Station (SSES) Probabilistic Risk Assessment (PRA)and the U.S. Nuclear Regulatory Commissions (NRC) Standardized Plant Analysis Risk (SPAR) model. Additionally, the SSES Units 1 and 2, Significance Determination Process (SDP) analysis was referenced in the selection of potential components for review. In general, the selection process focused on components that had a Risk Achievement Worth (RAW) factor greater than 1.3 or a Risk Reduction Worth (RRW)factor greater than 1.005. The team also selected components based on previously identified industry operating experience issues and component contribution to the large early release frequency (LERF) was also considered. The components selected were located within both safety-related and non-safety related systems, and included a variety of components such as pumps, breakers, heat exchangers, electrical buses, transformers, and valves.

The team initially compiled a list of components based on the risk factors previously mentioned. Additionally, the team reviewed the previous component design bases inspection report (05000387/388-2007007 and 05000387/388-2010007) and excluded those components previously inspected. The team then performed a margin assessment to narrow the focus of the inspection to 18 components and 3 operating experience (OE) samples. One component was selected because it was a containment-related structure, system, and component (SSC) and was considered for LERF implications. The teams evaluation of possible low design margin components included consideration of original design issues, margin reductions due to modifications, or margin reductions identified as a result of material condition/equipment reliability issues.

The assessment also included items such as failed performance test results, corrective action history, repeated maintenance, maintenance rule (a)1 status, operability reviews for degraded conditions, NRC resident inspector insights, system health reports, and industry operating experience. Finally, consideration was given to the uniqueness and complexity of the design and the available defense-in-depth margins.

The inspection performed by the team was conducted as outlined in NRC Inspection Procedure (IP) 71111.21. This inspection effort included walkdowns of selected components; interviews with operators, system engineers, and design engineers; and reviews of associated design documents and calculations to assess the adequacy of the components to meet design basis, licensing basis, and risk-informed beyond design basis requirements. A summary of the reviews performed for each component, operating experience sample, and the specific inspection findings identified are discussed in the subsequent sections of this report. Documents reviewed for this inspection are listed in the Attachment.

.2.1.1 Unit 2, Reactor Core Isolation Cooling Pump

a. Inspection Scope

The team inspected the Unit 2 reactor core isolation cooling (RCIC) pump (2P203) to determine if it was capable of meeting its design basis and operational requirements assumed in the PPL PRA model to providing high pressure cooling water to the reactor vessel under transient and accident conditions. The team evaluated the ability of the RCIC pump to deliver the design and licensing bases flow rate at design pressure. The net positive suction head (NPSH) calculation for the RCIC pump was reviewed for maximum flow rates, from both the condensate storage tank (CST) and suppression pool, to verify that adequate NPSH was available at minimum water levels and atmospheric pressures. Additionally, the team reviewed a calculation to determine if the minimum water level procedurally allowed in the CST would prevent the formation of a vortex. The team reviewed full flow testing and in-service test (IST) results to verify that the pump performance bounded the flow requirements in the safety analysis and to determine if PPL had adequately evaluated the potential for pump degradation. The team performed a walkdown of the pump and associated support features and interviewed system and design engineers to assess the material condition of the pump.

Finally, the team reviewed corrective action documents and system health reports to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.2 Spray Pond A1 Inlet Valve and Spray Pond Loop B Bypass Valve (2 samples)

a. Inspection Scope

The team inspected the spray pond A1 inlet valve and spray pond loop B bypass valve (HS01222B and HV1224A1) to determine if the valves were capable of performing their design basis functions. Specifically, the team verified that the bypass valve would reposition, as required, to provide an adequate return flow path for the residual heat removal service water (RHRSW) and emergency service water (ESW) systems to the spray pond. Also, the team verified that the inlet valve would subsequently open to provide cooling of the spray pond. The team reviewed the Updated Final Safety Analysis Report (UFSAR), Technical Specifications (TS), TS Bases, and the IST basis documents to identify the design basis requirements for the valves, including design changes performed as part of the reactor power uprate. The team reviewed periodic motor-operated valve (MOV) diagnostic test results and stroke-timing test data to verify acceptance criteria were met. The team also evaluated whether the MOV safety functions, performance capability, torque switch configuration, and design margins were adequately monitored and maintained in accordance with generic letter (GL) 89-10 guidance. The team reviewed MOV weak link calculations to ensure the ability of the valves to remain structurally functional while stroking under design basis conditions.

The team verified that the valve analysis used the maximum differential pressure expected across the valve during worst case operating conditions. Additionally, the team reviewed motor data, degraded voltage conditions, and voltage drop calculation results to confirm that the MOV would have sufficient voltage and power available to perform its safety function at degraded voltage conditions. The team reviewed operating and emergency procedures for the valves to determine whether the procedures provide adequate direction to operators so that the design function and limits of the spray pond are maintained under accident conditions. The team discussed the design, operation, and component history of the valves with engineering and operations staff to determine performance history and overall component health. Finally, the team reviewed corrective action documents to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.3 A Emergency Service Water Pump

a. Inspection Scope

The team inspected the A ESW pump (0P504A) to evaluate if it was capable of performing its design basis functions. Specifically, the team evaluated whether the pump capacity was sufficient to provide adequate flow to the safety-related components supplied by the ESW system during design basis accidents (DBA). The team reviewed applicable portions of the UFSAR, design basis document (DBD), and drawings to identify the design basis requirements for the pump. The team reviewed design calculations to assess available pump NPSH under worst case pump run-out conditions, and to evaluate the capability of the pump to provide required flow to supplied components. Additionally, the team reviewed the ESW pump motor data, degraded voltage conditions, and voltage drop calculations to confirm that the pump motor would have sufficient voltage and power available to perform its safety function at degraded voltage conditions. The team reviewed the ESW pump IST results and ESW system flow verification tests to verify that adequate system flow was available. Specifically, the team reviewed pump data trends for vibration, pump differential pressure, and flow rate test results to verify acceptance criteria were met and acceptance limits were adequate.

The team ensured changes that impacted flow requirements to individual ESW system loads due to changes in fouling factors, pipe replacement, modifications, and revised heat load requirements for components were properly evaluated. The team interviewed the system engineer and performed a walkdown of the pump to evaluate its material condition and assess the pump's operating environment. The team also walked down accessible portions of the ESW pumphouse structure to assess the material condition of the structure, intake silt/debris loading, and PPL's configuration control. Finally, the team reviewed corrective action documents and system health reports to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

2.1.4 Unit 1, Feedwater Inlet Line B Stop Check Valve

a. Inspection Scope

The team inspected feedwater inlet line B stop check valve (HV141F032B) to determine whether it was capable of meeting its design basis requirement. Specifically, the team evaluated whether the check valve, an outboard primary containment isolation valve (PCIV), would close in order to ensure high pressure coolant injection (HPCI)system flow is directed to the reactor vessel during a DBA. The team reviewed IST results to verify that the associated test acceptance requirements were being met and to determine if leakage test limits were adequate to ensure HPCI system flow requirements were satisfied. The team reviewed engineering changes and evaluations related to the valve to evaluate whether design requirements had been maintained. Finally, the team reviewed corrective action documents to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.5 Unit 1, Reactor Water Cleanup Inlet Outboard Isolation Valve

a. Inspection Scope

The team inspected the reactor water cleanup (RWCU) inlet outboard isolation valve (HV144F004) to evaluate if it was capable of performing its design basis functions.

Specifically, the team verified that the valve would reposition to prevent flow into the RWCU system following actuation of the standby liquid control (SBLC) system during an anticipated transient without scram (ATWS) event and reposition to isolate the primary system from the reactor water cleanup during certain DBAs. The team reviewed the UFSAR, TS, TS Bases, and the IST basis documents to identify the design basis requirements of the valve. The team reviewed periodic MOV diagnostic test results and stroke-timing test data to verify acceptance criteria were met. The team also evaluated whether the MOV safety functions, performance capability, torque switch configuration, and design margins were adequately monitored and maintained in accordance with generic letter (GL) 89-10 guidance. The team reviewed MOV weak link calculations to ensure the ability of the valve to remain structurally functional while stroking under design basis conditions. The team verified that the valve analysis used the maximum differential pressure expected across the valve during worst case operating conditions.

Additionally, the team reviewed motor data, degraded voltage conditions, and voltage drop calculation results to confirm that the MOV would have sufficient voltage and power available to perform its safety function at degraded voltage conditions. The team discussed the design, operation, and component history of the valve with engineering and operations staff to determine performance history and overall system health. The team performed a walkdown of accessible areas of the RWCU system and controls to assess material condition. Finally, the team reviewed corrective action documents and system health reports to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.6 Unit 1, Standby Liquid Control Check Valve

a. Inspection Scope

The team inspected a SBLC check valve (148F007) to evaluate whether the valve was capable of performing its design basis function. Specifically, the team determined whether the valve would open to provide a flow path for the SBLC pumps during an ATWS event. The team reviewed the UFSAR, the TSs, design basis documents, drawings, and procedures to identify the design basis requirements of the valve. The team then reviewed the check valve inspection results to verify acceptance criteria were met and to evaluate if the acceptance criteria ensured the design basis requirements for the valve were maintained. The team discussed the design, operation, and maintenance of the valve with engineering staff to evaluate component performance history, maintenance, and overall component health. The team also conducted a walkdown of the valve and associated system to assess material condition and to verify the installed configuration of the valve and system was consistent with the plant drawings and the design and licensing bases.

b. Findings

No findings were identified.

.2.1.7 A Emergency Diesel Generator - Mechanical

a. Inspection Scope

The team inspected the A emergency diesel generator (EDG) (OG501A) mechanical systems to determine if they were capable of supporting the design basis function of the EDG. Specifically, the team evaluated whether the mechanical support systems for the EDG would operate as required so that the EDG could provide power to the 4.16 kV electrical bus during operational transients and design basis events. The team selected the EDG engine, fuel oil system, air start system, exhaust system, lubricating oil system, and jacket water cooling system for an in-depth review. The team reviewed the UFSAR, the TSs, operating procedures, and DBD to identify the design basis requirements for these systems. The team reviewed EDG surveillance test results, equipment operator logs, and operating procedures to ensure that the mechanical support systems were operated as designed and within the vendor design limits. The team reviewed fuel oil consumption calculations to verify TS requirements were adequate to meet design basis loading conditions. The team reviewed lubricating oil sample and chemistry results to assess whether PPL had performed timely analysis for wear and trending, identified potential adverse trends, and to determine if proper lubrication of system components was being performed. The team reviewed the EDG vendor manual and preventive maintenance (PM) activities to ensure that PPL maintained an appropriate threshold for corrective actions prior to any adverse impact on engine operation. The team observed the overhaul of the #1R power pack on the A EDG for cylinder liner and piston ring replacement in response to cylinder liner seal leakage, and reviewed the post maintenance test run data. The team conducted several detailed walkdowns of the EDG and its support systems (including control room instrumentation) to visually inspect the material condition, to assess the operating environment and potential hazards, and to ensure adequate configuration control. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.8 Unit 1, B Residual Heat Removal Heat Exchanger

a. Inspection Scope

The team inspected the 1B residual heat removal (RHR) heat exchanger (1E205B) to determine if it was capable of meeting its design basis function. Specifically, the team evaluated the ability of the heat exchanger to adequately remove decay heat following postulated DBAs. The team reviewed applicable portions of the UFSAR, DBD, TS and drawings to identify the design basis requirements for the heat exchanger. The team also reviewed design calculations to evaluate the capability of the heat exchanger to transfer the required heat load during normal operations and postulated accident conditions, including calculations made as part of the reactor power uprate. The team also reviewed the heat exchanger internal inspection procedure and results to determine if the inspection program met the commitments made in PPLs 89-13 response and to evaluate whether the inspection results supported assumptions in the design calculations. The team interviewed system and design engineers, reviewed corrective action documents, and performed a walkdown of the heat exchanger to assess the material condition of the equipment. Finally, the team reviewed corrective action documents to evaluate whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.9 Unit 2, B Condensate Storage Tank

a. Inspection Scope

The team inspected the B CST (0T522B) to determine if it was capable of meeting its design basis function. Specifically, the team evaluated whether the tank was adequately designed to provide the required quantity of water, as the preferred source of water, for the HPCI pump and the RCIC pump during design basis events. The team reviewed applicable portions of the UFSAR, DBD, TS and drawings to identify the design basis requirements for the system. The team reviewed the design, testing, inspection, and operation related to the CST and associated tank level instruments to evaluate whether the tank could perform its design basis function. Specifically, the team reviewed design calculations, drawings, and vendor specifications including tank sizing, level uncertainty analysis, and pump vortex calculations to evaluate the adequacy and appropriateness of design assumptions and operating limits. The team interviewed system and design engineers and reviewed instrument test records and tank inspection results to determine whether maintenance and testing was adequate to ensure reliable operation.

Additionally, the teams review evaluated whether those activities were performed in accordance with regulatory requirements, industry standards, and vendor recommendations. The team also conducted a walkdown of the tank area to independently assess the material condition of the CST and associated instrumentation.

Finally, the team reviewed corrective action documents to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 0 Unit 1, High Pressure Coolant Injection Suction Strainer

a. Inspection Scope

The team inspected the HPCI system suction strainer (1F402A) to evaluate whether the HPCI system could meet its design bases requirements. Specifically, the team determined whether the strainer was adequately designed to prevent debris from impacting the operation of the HPCI pump during a DBA. The team reviewed applicable portions of the UFSAR, DBD, TS, and drawings to identify the design basis requirements for the strainer. The team reviewed strainer calculations to evaluate whether the differential pressure across the strainer due to the assumed debris loading was consistent with assumptions used in the strainer structural load calculation and the HPCI net positive suction head calculations. Additionally, the team evaluated whether the strainer openings were sized such that material that bypasses the strainer was small enough such that HPCI operation would not be affected. Finally, the team reviewed condition reports and system health reports and interviewed system and design engineers to determine the overall health of the suction strainers and to determine if issues entered into the corrective action program were properly addressed.

b. Findings

No findings were identified.

.2.1.1 1 Unit 2, Emergency Safety System Load Center Transformer Breaker

a. Inspection Scope

The team inspected the 480 Vac load center transformer breaker (1A20106) to determine if it was capable of performing its design basis functions. Specifically, the team evaluated whether the breaker was capable of transferring supplied power to downstream loads following a DBA. The team reviewed electrical distribution calculations including load flow, voltage drop, short-circuit, and electrical protection coordination to evaluate the adequacy and appropriateness of design assumptions. The team also evaluated whether breaker capacity and voltages remained within acceptable values under design basis conditions. The team reviewed the electrical overcurrent protective relay settings for the load center supply breaker and selected load center breakers to verify that the trip setpoints would ensure the ability of the supplied equipment to perform both its design basis safety function and also provide adequate load center protection during fault conditions. Additionally, the team reviewed system maintenance test results, interviewed system and design engineers, and conducted field walkdowns of the breaker to evaluate whether the equipment alignment, nameplate data, and breaker position were consistent with design drawings and to assess the material condition. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 2 Unit 2, Emergency Safety System 480Vac Load Center Transformer

a. Inspection Scope

The team inspected the 480 Vac load center transformer (2X210) to determine if it was capable of performing its design basis functions. Specifically, the team evaluated whether the supply transformer was capable of transferring supplied power to downstream loads on its associated vital bus following a DBA. The team reviewed electrical distribution calculations including load flow, voltage drop, short-circuit, and electrical protection coordination to evaluate the adequacy and appropriateness of design assumptions. The team also evaluated whether the transformer capacity and input and output voltages remained within acceptable values under design basis conditions. The team reviewed the electrical overcurrent protective relay settings for the transformer supply breaker to verify that the trip setpoints would ensure the ability of the transformer to perform its design basis safety function and the setpoints would provide adequate protection of equipment during fault conditions. Additionally, the team reviewed system maintenance test results, interviewed system and design engineers, and conducted field walkdowns to verify that equipment alignment, nameplate data, and breaker positions were consistent with design drawings and to assess the material condition of the transformer. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 3 Unit 1, 4kV Emergency Safety System Auxiliary Bus

a. Inspection Scope

The team inspected the 4.16kV vital bus (1A202) to determine if it was capable of meeting its design basis functions. Specifically, the team evaluated whether the bus was capable of transferring supplied power to downstream loads during a DBA. The team reviewed applicable portions of the UFSAR, DBD, and drawings to identify the design basis requirements for the bus. The team reviewed selected calculations for the electrical distribution systems load flow/voltage drop, degraded voltage protection, short-circuit protection, and short circuit coordination to evaluate the adequacy and appropriateness of design assumptions in the calculations. The teams review evaluated whether bus and breaker capacity would be exceeded and whether bus voltages remained above minimum acceptable values under design basis conditions. The team also reviewed switchgear protective device settings and breaker ratings to ensure that selective coordination was adequate for the protection of connected equipment during short-circuit conditions. The team reviewed the preventive maintenance inspection and testing procedure and associated test results to ensure that breakers were maintained in accordance with industry and vendor recommendations. The team also reviewed calculations to evaluate whether adequate voltage would be available for the breaker closure and opening control circuit components and the breaker spring charging motors.

Additionally, the team performed a visual inspection of observable portions of the safety-related switchgear to assess the installed configuration, material condition, environmental condition, and potential vulnerability to hazards. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 4 Unit 1, Vital Alternating Current Uninterrupted Power Supply

a. Inspection Scope

The team inspected the vital alternating current (AC) uninterrupted power supply (UPS)

(1D666) to determine whether it was capable of meeting its design basis functions.

Specifically, the team evaluated the inverters capability to provide power to the required loads during transients. The team reviewed the loading profile for the UPS in order to determine the design basis for maximum loading. The team then evaluated whether the inverter equipment ratings were within the design basis loading requirements. The team also reviewed calculations to determine if the inverter was capable of providing the 120/208Vac system loads with adequate voltage during design basis conditions.

Additionally, the team reviewed short circuit fault current and breaker coordination calculations to verify that proper coordination existed. The team conducted walkdowns at the inverter to assess the observable material condition and to evaluate whether the installation was in accordance with manufacturer instructions. Finally, the team reviewed corrective action documents to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 5 Unit 1, Channel A 125V Direct Current Emergency Safety System Distribution Panel

a. Inspection Scope

The team inspected the channel A 125 volt direct current (Vdc) emergency safety system distribution panel (1D614) to evaluate whether it was capable of meeting its design basis requirements. Specifically, the team reviewed the design and operation of the switchgear distribution panel to evaluate whether the loading of the panel was within equipment ratings and whether the panel could perform its design basis function to supply reliable power to associated loads under worst case conditions. The team reviewed calculations and drawings including voltage drop calculations, short circuit analyses, and load study profiles to evaluate the adequacy and appropriateness of design assumptions. The team also reviewed the direct current (DC) overcurrent protective coordination studies to evaluate whether there was adequate protection for postulated faults in the DC system. Additionally, the team reviewed maintenance procedures and schedules for the 125Vdc panel and associated circuit breakers to determine whether the equipment was being maintained in accordance with vendor recommendations. The team interviewed system and design engineers and walked down the 125Vdc distribution panels to independently assess its material condition and to determine whether the system alignment and operating environment was consistent with design basis assumptions. Finally, the team reviewed corrective action documents and system health reports to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 6 Unit 1, 125VDC Circuit Breaker

a. Inspection Scope

The team inspected the 125Vdc circuit breaker (1D61212) to evaluate whether it was capable of meeting its design basis requirements. The team reviewed bus loading calculations to evaluate whether the 125Vdc breaker had sufficient capacity to supply its required loads under worst case accident loading conditions. The team reviewed cable sizing calculations to ensure that cables were adequately sized for load and service conditions. The team also reviewed 125Vdc short circuit calculations to verify that the breaker was adequately sized and to verify that the breaker short circuit interrupting ratings exceeded the maximum calculated short circuit currents. Additionally, the team reviewed breaker coordination studies to evaluate whether equipment was protected and protective devices provided selective coordination. The team reviewed maintenance procedures and preventive maintenance schedules for the breaker to evaluate whether the equipment was being maintained in accordance with vendor recommendations. Additionally, the team performed a visual inspection of the 125Vdc switchgear and breaker to assess the material condition of the equipment. Finally, the team reviewed corrective action documents and system health reports to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 7 Unit 2, A Reactor Pressure Vessel Level Narrow Range Instrument

a. Inspection Scope

The team inspected the A reactor pressure vessel level narrow range instrument (LISB212N042A) to determine if it was capable of meeting its design basis requirements.

Specifically, the team evaluated whether the level instrument was capable of determining reactor vessel level and transmitting accurate level indication to control circuitry during a DBA. The team reviewed applicable portions of the UFSAR, DBD, and drawings to identify the design basis requirements for the level instrument. The team reviewed the environment qualification (EQ) report to verify that the qualification of the device was for application as a Class 1E component in a harsh environment. The team reviewed instrument and loop uncertainty calculations to determine whether all uncertainties were accounted for and adequate margin existed between actual and design basis requirements. The team also reviewed TS required surveillances to evaluate whether licensing requirements were met. Finally, the team reviewed corrective action documents to determine whether there were any adverse operating trends and to assess PPL's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.2 Review of Industry Operating Experience and Generic Issues (3 samples)

The team reviewed selected OE issues for applicability at the SSES. The team performed a detailed review of the OE issues listed below to evaluate whether PPL had appropriately assessed potential applicability to site equipment and initiated corrective actions when necessary.

.2.2.1 Inspection of Information Notice 1997-90: Use of Non-conservative Acceptance Criteria

in Safety-Related Pump Surveillance Tests

a. Inspection Scope

The team reviewed the licensees evaluation of NRC Information Notice 1997-90, Use of Non-conservative Acceptance Criteria in Safety-Related Pump Surveillance Tests, to evaluate whether PPLs review adequately addressed the industry operating experiences discussed in the information notice. Specifically, the team reviewed PPLs evaluation to ensure the review addressed the information discussed in the concerns described in the information notice related to the use of non-conservative IST acceptance criteria. Additionally, the team reviewed the IST acceptance criteria for several safety related pumps to determine whether the limits bounded the associated design basis requirements.

b. Findings

No findings were identified.

.2.2.2 NRC Information Notice 93-64: Periodic Testing and Preventive Maintenance of Molded

Case Circuit Breakers

a. Inspection Scope

The team evaluated PPLs applicability review and disposition of NRC Information Notice 93-64, Periodic Testing and Preventive Maintenance of Molded Case Circuit Breakers.

The NRC issued this information notice to alert the licensees to the problem of age-related degradation of molded case circuit breakers (MCCB) and to provide sources of information on MCCB periodic testing and preventive maintenance. The team reviewed PPLs response and their subsequent actions to establish a preventive maintenance and testing program for MCCBs installed in 480V and below load centers and AC and DC motor control centers (MCC).

b. Findings

Introduction.

The team identified a finding of very low safety significance (Green)involving a non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that, PPL failed to verify or check the adequacy of design of MCCBs. The team found that these breakers were credited to protect primary containment electrical penetrations from damage during overload or fault conditions and that PPL did not verify the safety-related 125Vdc MCCBs would perform this safety function.

Description.

The team reviewed PPL response to the NRC Information Notice 93-64, Periodic Testing and Preventive Maintenance of Molded Case Circuit Breakers. The team determined that PPL had not included the 125Vdc and 120Vac MCCBs, installed in distribution panels, in their evaluation. Subsequently, the team requested the preventive maintenance procedure for maintaining and periodically testing these MCCBs. In response, PPL stated that testing of 125Vdc and 120Vac MCCBs were not included in their PM program and were original plant equipment. The team noted that the operating experience (NRC Information Notice 93-64) discussed that MCCBs can be subjected to age-related degradation. The information notice found that detecting and assessing age-related degradation could only be accomplished through appropriate periodic testing and monitoring.

The team reviewed PPLs UFSAR and found that Section 3.13 describes the external circuit protection for electrical penetration assemblies in containment structures. The UFSAR states that, each 125 VDC control circuit is protected by a 20 amp or smaller fuse located in a control panel with back-up protection provided by a 20 amp breaker in the dc distribution panel. The team also found time-current characteristic curves for fuse, breaker, and penetration conductors depicted in UFSAR Figure 3.13-5 indicated that proper coordination between the breaker and power cable is required to be maintained in order to protect the containment penetration from damage during fault conditions. The team concluded that the overcurrent and instantaneous trip functions of these breakers have a safety related function for the MCCB because they are credited to operate in order to maintain the mechanical integrity of primary containment penetration assemblies under overload or fault conditions.

The team requested PPL identify whether any of the MCCBs not being tested were part of the containment electrical penetration overcurrent protection scheme. In response, PPL determined that the Automated Depressurization System (ADS) solenoid valves, located inside containment, are energized by 125Vdc MCCBs installed in distribution panels. The team noted that these MCCBs had been installed in the plant during original construction and had never been tested or subjected to preventive maintenance.

Therefore, the team concluded the safety-related function, protecting containment electrical penetration under overload or fault conditions, had not been demonstrated.

To address the teams concern, PPL entered this issue in their corrective action program under CR 1732454. PPL performed a review of their corrective action database to identify any failures related to these breakers or the associated fuses in the protection circuit. The review did not identify any failure. Additionally, PPL noted that degradation of the fuse portion of the protective circuit would not prevent the fuse from isolating a fault. PPL concluded that the containment penetrations remained operable but non-conforming because one of the trip devices in the containment electrical penetration protection scheme would function during overcurrent or short circuit faults. The team determined this conclusion to be reasonable.

Analysis.

The team determined that PPLs failure to verify the adequacy of the safety-related function of MCCBs was a performance deficiency that was reasonably within PPLs ability to foresee and prevent. The finding was more than minor because it was associated with the Barrier Integrity cornerstone objective to provide reasonable assurance that physical design barriers (containment) protect the public from radionuclide release caused by accidents or events and adversely affected the Design Control and Configuration Control attributes related to maintaining the functionality of containment. The team assessed this finding in accordance with the NRC IMC 0609, Significance Determination Process, Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Exhibit 3, Barrier Integrity Screening Questions, Section B, Reactor Containment the team concluded that this performance deficiency did not represent an actual open pathway in the physical integrity of reactor containment and did not involve an actual reduction in the function of hydrogen igniters in the reactor containment. Therefore, the finding was determined to be of very low safety significance (Green).

The team determined that the finding did not have a cross-cutting aspect because it was not indicative of current performance because the PPL maintenance and testing program for the breakers was based on their response to the NRC Information Notice which was completed in October 1993.

Enforcement.

The team identified a violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, which states, in part, design control measures shall provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program. Contrary to the above, prior to August 2013, PPL did not provide design control measures to verify or check the adequacy of the design for 125Vdc MCCBs to ensure that the safety-related function credited to provide external circuit protection of primary containment electrical penetrations under the overload or faults conditions, was maintained. Because the finding was of very low safety significance and has been entered into PPLs corrective action program (CR 1732454), this violation is being treated as non-cited violation (NCV), consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000387;05000388/2013010-01, Failure to Verify Operation of Safety-Related 125Vdc Molded Case Circuit Breakers)2.2.3 NRC Information Notice 2012-01: Design Vulnerability in Electric Power System

a. Inspection Scope

The team reviewed NRC Bulletin 2012-01 and the licensees approach to the issues described in the Bulletin. The licensee had provided a response to the NRC which outlined the main steps to be taken, including performance of detailed calculations and implementation of possible solutions to detect open phase conditions and to protect safety-related equipment. The calculations had not been performed at the time of the inspection. The team reviewed the switchyard surveillance procedures and reports, and the interface agreement between the plant and the grid operator to ensure surveillance procedures were adequate to detect open phase conditions.

b. Findings

No findings were identified.

4OA2 Identification and Resolution of Problems (IP 71152)

a. Inspection Scope

The team reviewed a sample of problems that PPL identified and entered into their corrective action program. The team reviewed these issues to evaluate if PPL had an appropriate threshold for identifying issues and to evaluate the effectiveness of corrective actions. In addition, corrective action documents written on issues identified during the inspection were reviewed to evaluate adequate problem identification and incorporation of the problem into the corrective action program. The corrective action documents that were reviewed by the team are listed in the Attachment.

b. Findings

No findings were identified.

4OA6 Meetings, including Exit

On August 29, 2013, the team presented the inspection results to Mr. William Bishop, General Manager Maintenance, and other members of the PPL staff. The team verified that none of the information in this report is proprietary.

ATTACHMENT

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee Personnel

G. Lubinsky Design Engineering Manager

R. Vazquies Mechanical Design Engineer

M. Lingenfelter Station Engineering Manager

J. Hartell PRA Supervisor

P. Scanlan Engineering Manager

D. Filcher Sr. Licensing Engineer

D. Kostelnik Mechanical Design Supervisor

D. Przyjemski Senior Engineer

W. Bishop Maintenance General Manager

M. Gosekamp Programs General Manager

I. Nembo Electrical Engineer

C. Angione Electrical Engineer

A. Allen EDG Systems Engineer

A. Klopp Senior Engineer

LIST OF ITEMS

Opened and Closed

05000387;

05000388/2013010-01 NCV Failure to Verify Operation of Safety-Related 25Vdc Molded Case Circuit Breakers (Section 1R21.2.2.2)