IR 05000275/2016007

NRC Component Design Bases Inspection Report 05000275/2016007 and 05000323/2016007

ML16112A422
Person / Time
Site:	Diablo Canyon
Issue date:	04/21/2016
From:	Thomas Farnholtz Region 4 Engineering Branch 1
To:	Halpin E Pacific Gas & Electric Co
References
IR 2016007
Download: ML16112A422 (71)

Text

ril 21, 2016

SUBJECT:

DIABLO CANYON POWER PLANT, UNITS 1 AND 2 - NRC COMPONENT DESIGN BASES INSPECTION REPORT 05000275/2016007 AND 05000323/2016007

Dear Mr. Halpin:

On March 10, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Diablo Canyon Power Plant, Units 1 and 2. The NRC inspectors discussed the results of this inspection with Mr. J. Welsch, Site Vice President, and other members of your staff.

On April 7, 2016, the NRC inspectors discussed the final results of this inspection with Mr. R. Waltos, Acting Director, Engineering, Mr. T. Baldwin, Director, Nuclear Site Services, and other members of your staff. The inspectors documented the results of this inspection in the enclosed inspection report.

The NRC inspectors documented six findings of very low safety significance (Green) in this report. All of these findings involved violations of NRC 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 IV; the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC resident inspector at the Diablo Canyon Power Plant, Units 1 and 2.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region IV; and the NRC resident inspector at the Diablo Canyon Power Plant, Units 1 and 2. In accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding, of the NRC's "Rules of Practice and Procedure," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRCs Public Document Room or from the Publicly Available Records (PARS)

component of the NRC's Agencywide Documents Access and Management 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/

Thomas R. Farnholtz, Chief Engineering Branch 1 Division of Reactor Safety Docket Nos. 50-275 and 50-323 License Nos. DPR-80 and DPR-82

Enclosure:

Inspection Report 05000275/2016007 and 05000323/2016007 w/Attachment:

Supplemental Information

REGION IV==

Dockets: 05000275; 05000323 Licenses: DPR-80; DPR-82 Reports: 05000275/2016007; 05000323/2016007 Licensee: Pacific Gas and Electric Company Facility: Diablo Canyon Power Plant, Units 1 and 2 Location: 7 1/2 miles NW of Avila Beach Avila Beach, CA Dates: February 8 through March 10, 2016 Team Leader: J. Braisted, Reactor Inspector, Engineering Branch 1 Inspectors: C. Steely, Operations Engineer, Operations Branch M. Hayes, Operations Engineer, Operations Branch N. Okonkwo, Reactor Inspector, Engineering Branch 2 R. Kopriva, Senior Reactor Inspector, Engineering Branch 1 R. Latta, Senior Reactor Inspector, Engineering Branch 1 Senior Reactor D. Loveless, Senior Reactor Analyst, Plant Support Branch 2 Analyst:

Accompanying H. Leake, Contractor, Beckman and Associates Personnel: J. Zudans, Contractor, Beckman and Associates Approved By: Thomas R. Farnholtz, Chief Engineering Branch 1 Division of Reactor Safety-1- Enclosure

SUMMARY

IR 05000275; 05000323/2016007; 02/08/2016 - 03/10/2016; Diablo Canyon Power Plant,

Units 1 and 2: Baseline inspection, NRC Inspection Procedure 71111.21, Component Design Bases Inspection.

The inspection activities described in this report were performed between February 8, 2016, and March 10, 2010, by six inspectors from the NRCs Region IV office and two contractors.

Six findings of very low safety significance (Green) are documented in this report. All of these findings involved violations of NRC requirements. The significance of inspection findings is indicated by their color (Green, White, Yellow, or Red), which is determined using Inspection Manual Chapter 0609, Significance Determination Process. Their cross-cutting aspects are determined using Inspection Manual Chapter 0310, Aspects within the Cross-cutting Areas.

Violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process.

Cornerstone: Mitigating Systems

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion III, Design Control, which states, in part, The design control measures shall provide for verifying or checking the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.

Specifically, prior to September 10, 2013, the licensee failed to verify the design of 480 Vac combination motor starter instantaneous magnetic circuit breakers settings, by the use of alternate or simplified calculational methods, for those breakers whose settings are higher than their manufacturers' specifications, as documented in calculation 195B-DC, MCCB Settings for 460VAC Class 1E Motors, to provide the required level of protection and ensure that certain failures that could be caused by sustained fault currents below the circuit breaker trip setting would not occur. In response to this finding, the licensee conducted a preliminary evaluation of some of the affected equipment and concluded that sustained fault currents below the trip settings are unlikely. This finding was entered into the licensee's corrective action program as Notification 50838071.

The team determined the failure to evaluate 480 Vac combination motor starters with instantaneous magnetic circuit breaker trip current settings higher than their manufacturers'

specifications was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences.

Specifically, improper motor starter breaker trip settings could result in a fire in the motor control center cubicle, damage to motor starter components, spurious tripping of the entire motor control center, or lack of protection for downstream components during fault conditions. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding did not have a cross-cutting aspect because the most significant causal factor of the performance deficiency did not reflect current licensee performance. (Section 1R21.2.3.b.1)

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion XVI, Corrective Action, which states, in part, Measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected. Specifically, prior to March 16, 2016, the licensee failed to assure that the lack of design verification of 460 Vac motors, which could be overloaded at the maximum allowable diesel generator frequency, was promptly corrected after having been identified in a 2013 apparent cause evaluation and again in a 2015 self-assessment as documented in Notifications 50572850 and 50826105, respectively. In response to this finding, the licensee performed a preliminary evaluation of the affected 460 Vac motors and concluded that operation at maximum emergency diesel generator frequency would not cause them to overheat or trip on overcurrent. This finding was entered into the licensee's corrective action program as Notifications 50835699 and 50838988.

The team determined the failure to correct the lack of design verification of 460 Vac motors at maximum allowable frequency when powered from the emergency diesel generators was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, operation of 460 Vac motors above their rated or analyzed maximum allowable frequencies could result in motor overheating or a trip of the thermal overload relays. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of problem identification and resolution associated with evaluation because the licensee failed to ensure that the organization thoroughly evaluated issues to ensure that resolutions address causes and extent of conditions [P.2]. (Section 1R21.2.3.b.2)

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion III, Design Control, which states, in part, The design control measures shall provide for verifying or checking the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.

Specifically, prior to February 10, 2016, the licensee failed to verify the design of (1) equipment on the nominally 125 Vdc system at the maximum voltage specified in Procedure OP J-9:IV, Performing a Battery Equalizing Charge, and (2) equipment on 480 Vac and 120 Vac vital buses at maximum voltages specified in Procedure OP J-2:VIII,

Guidelines for Reliable Transmission Service for DCPP, by the use of alternate or simplified calculational methods, to ensure equipment functionality. In response to this finding, the licensee conducted a preliminary evaluation of the affected equipment and concluded that any past exposure to voltages above their maximum rating would not have caused a loss of functionality. This finding was entered into the licensee's corrective action program as Notifications 50834558, 50835906, 50835394, 50835945, 50835949, 50836376, 50836439, 50836638, 50836872, and 50836995.

The team determined the failure to evaluate operation of 125 Vdc and 480 and 120 Vac equipment at maximum allowable voltages was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the equipment performance attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, operation of equipment outside of its rated or analyzed maximum allowable voltages adversely affects the reliability and capability of that equipment required to perform safety-related functions. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6]. (Section 1R21.2.4.b)

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion V, Instructions, Procedures, and Drawings, which states, in part, Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Specifically, in October of 2015, the licensee failed to evaluate the extent of condition of a cracked holding pawl on a nonsafety-related 4160 Vac SF6 breaker, which was procured as safety-related, in accordance with Procedure OM7.ID1, Problem Identification and Resolution, when the failure of the component could adversely impact safety-related breakers of the same make and model. In response to this finding, the licensee is performing a procedure review to include steps to perform an extent of condition analysis for unplanned nonsafety-related equipment issues that may also affect similar safety-related equipment. This finding was entered into the licensee's corrective action program as Notifications 50836859 and 50836689.

The team determined the failure to evaluate the impact of a cracked holding pawl identified on a nonsafety-related 4160 Vac SF6 breaker on additional safety-related 4160 Vac SF6 breakers was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the equipment performance attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences.

Specifically, the 4160 Vac breaker with the cracked holding pawl was procured as safety-related; therefore, the condition extends to safety-related 4160 Vac breakers of the same make and model and potentially adversely affects the ability to perform their safety function.

In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with conservative bias because the licensee failed to ensure that individuals used decision-making practices that emphasized prudent choices [H.14]. (Section 1R21.2.5.b)

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion III, Design Control, which states, in part, The 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. Specifically, prior to January 30, 2014, the licensee failed to verify the design of the 230 kV preferred offsite power source, such as by the performance of design reviews or use of alternate or simplified calculational methods, by assuming in calculation 359-DC, Determination of 230 kV Grid Capability Limits as DCPP Offsite Power Source, that the reactor trip and engineered safety features actuation system signals are coincident in time for all postulated design basis events. However, the plant is designed such that, during some events, the signals are separate in time and would result in a greater vital bus voltage depression than analyzed. In response to this finding, the licensee conducted a preliminary evaluation and concluded that the current transmission grid conditions were such that the calculation criteria would be met in the event of a design basis event involving non-coincident reactor trip and engineered safety features actuation system signals. This finding was entered into the licensee's corrective action program as Notification 50839137.

The team determined the failure to evaluate the voltage effects of a limiting design basis event with non-coincident reactor trip and engineered safety features actuation system signals on the 230 kV offsite power circuit was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to ensure adequate bus voltages as a result of a design basis event with non-coincident reactor trip and engineered safety features actuation system signals would result in a trip of the undervoltage relays and the loss of the preferred offsite power circuit. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6]. (Section 1R21.3.1.b.1)

Green.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B,

Criterion V, Instructions, Procedures, and Drawings, which states, in part, Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.

Specifically, prior to November 25, 2015, the licensee failed to include appropriate quantitative acceptance criteria in Procedure MP E-62.3, Tap Changer Functional Test for Standby-Startup Transformer 11, to ensure that the load tap changer speed for standby-startup transformer 11 was adequate to restore vital bus voltages to the required level during design basis events. In response to this finding, the licensee performed a preliminary evaluation of the condition and concluded that the most recently measured speed of the load tap changer was adequate to ensure that it would restore vital bus voltage within the required time. This finding was entered into the licensee's corrective action program as Notification 50839333.

The team determined the failure to translate appropriate load tap changer timing acceptance criteria into functional tests to ensure that design assumptions were being maintained was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the load tap changer could meet its functional test acceptance criterion, but not operate fast enough to restore vital bus voltages within the required time during design basis events, which would result in an undervoltage trip and loss of the preferred offsite power circuit. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6]. (Section 1R21.3.1.b.2)

REPORT DETAILS

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity This inspection of component design bases verifies that plant components are maintained within their design basis. Additionally, this inspection provides monitoring of the capability of the selected components and operator actions to perform their design basis functions. As plants age, modifications may alter or disable important design features making the design bases difficult to determine or obsolete. The plant risk assessment model assumes the capability of safety systems and components to perform their intended safety function successfully. This inspectable area verifies aspects of the Initiating Events, Mitigating Systems, and Barrier Integrity cornerstones for which there are no indicators to measure performance.

1R21 Component Design Bases Inspection

.1 Overall Scope

To assess the ability of the Diablo Canyon Power Plant, Units 1 and 2, equipment and operators to perform their required safety functions, the team inspected risk-significant components and the licensees responses to industry operating experience. The team selected risk-significant components for review using information contained in the Diablo Canyon Power Plant, Units 1 and 2, probabilistic risk assessments and the NRC standardized plant analysis risk model. In general, the selection process focused on components that had a risk achievement worth factor greater than 1.3 or a risk reduction worth factor greater than 1.005. The items selected included components in both safety-related and nonsafety-related systems, including pumps, circuit breakers, heat exchangers, transformers, and valves. The team selected the risk-significant operating experience to be inspected based on its collective past experience.

To verify that the selected components would function as required, the team reviewed design basis assumptions, calculations, and procedures. In some instances, the team performed calculations to independently verify the licensee's conclusions. The team also verified that the condition of the components was consistent with the design basis and that the tested capabilities met the required criteria.

The team reviewed maintenance work records, corrective action documents, and industry operating experience records to verify that licensee personnel considered degraded conditions and their impact on the components. For selected components, the team observed operators during simulator scenarios, as well as during simulated actions in the plant.

The team performed a margin assessment and detailed review of the selected risk-significant components to verify that the design basis have been correctly implemented and maintained. This design margin assessment considered original design issues, margin reductions because of modifications, and margin reductions identified as a result of material condition issues. Equipment reliability issues were also considered in the selection of components for detailed review. These included items such as failed performance test results; significant corrective actions; repeated maintenance; 10 CFR 50.65(a)1 status; operable, but degraded, conditions; NRC resident inspector input of problem equipment; system health reports; industry operating experience; and licensee problem equipment lists. Consideration was also given to the uniqueness and complexity of the design, operating experience, and the available defense in-depth margins.

The inspection procedure requires a review of 15 to 25 total samples that include risk-significant and low design margin components, components that affect the large early release frequency (LERF) and operating experience issues. The sample selection for this inspection was 15 components, 1 component that affects LERF, and 5 operating experience items. The selected inspection and associated operating experience items supported risk-significant functions including the following:

a. Electrical power to mitigation systems: The team selected several components in the electrical power distribution systems to verify operability to supply alternating current (ac)and direct current

(dc) power to risk-significant and safety-related loads in support of safety system operation in response to initiating events such as loss of offsite power, station blackout, and a loss-of-coolant accident with offsite power available. As such the team selected:

• Diesel Generator 1-3 Instrument and Control System

• 4160 Volt Switchgear Bus 2F

• 480 Volt Switchgear 2F

• 125 Volt Distribution Panel and Bus 2-2

• 4160 Volt Feeder Breaker 52HF10

• 4160 Volt / 480 Volt Transformer 2F b. Components that affect LERF: The team reviewed a component required to perform functions that mitigate or prevent an unmonitored release of radiation. The team selected the following component:

• Containment Fan Cooler Unit 2-5 c. Mitigating systems needed to attain safe shutdown: The team reviewed components required to perform the safe shutdown of the plant. As such the team selected:

• Auxiliary Saltwater Pump 1-1

• Auxiliary Saltwater Traveling Screen 1-7

• Charging Pump Suction Valves LCV-112B and LCV-112C

• Component Cooling Water Pump 2-2

• Component Cooling Water Heat Exchanger Inlet Valves FCV-602 and FCV-603

• Condensate Storage Tank

• Pressurizer Power Operated Relief Valves PCV-455, PCV-456, and PCV-474

• Residual Heat Removal System Valves RHR-8701 and RHR-8702

.2.1 Diesel Generator 1-3 Instrument and Control System

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with diesel generator 1-3 instrument and control system. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Engineering changes and resultant design revisions, including work orders and condition reports

• Single-line and wiring diagrams of the local control panel, including functional descriptions

• Vendor manual for emergency diesel generator 1-3 instrument and controls

• Surveillance and preventive maintenance procedures and performed preventive maintenance, inspection, and testing documents

• Diesel generator 1-3 output traces, including observation of a field flash

• Output breaker sizing and protection calculations

b. Findings

No findings were identified.

.2.2 4160 Volt Switchgear 2F

a. Inspection Scope

The team reviewed the updated final safety analysis report, design basis documents, the current system health report, selected drawings, maintenance and test procedures, and condition reports associated with 4160 Volt switchgear 2F to ensure design basis requirements and specifications were met. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Calculations for electrical distribution system loading, steady-state and transient voltages, and maximum short-circuit levels to evaluate the adequacy of the switchgear bus and breakers to carry anticipated loads under limiting conditions

• Protective device settings and circuit breaker ratings to confirm adequate selective protection and coordination of connected equipment during worst-case short circuit conditions and to withstand and interrupt maximum available faults

• Degraded voltage and loss of voltage relay protection schemes that initiate automatic transfers from the offsite power supply to the diesel generator to assess adequacy of voltage at the terminals of the safety-related loads, and ability to remain connected to offsite power under worst operating and accident conditions

• Corrective action history to determine whether there had been any adverse operating trends

• Visual inspection to assess material condition, the presence of hazards, and consistency of installed equipment with design documentation and analyses

b. Findings

No findings were identified.

.2.3 480 Volt Switchgear 2F

a. Inspection Scope

The team reviewed the updated final safety analysis report, design basis documents, the current system health report, selected drawings, maintenance and test procedures, and condition reports associated with 480 Volt switchgear 2F to ensure design basis requirements and specifications were met. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Calculations for electrical distribution system loading, steady-state and transient voltages, and maximum short-circuit levels to evaluate the adequacy of the switchgear bus and breakers to carry anticipated loads under limiting conditions

• Protective device settings and circuit breaker ratings to confirm adequate selective protection and coordination of connected equipment during worst-case short circuit conditions and to withstand and interrupt maximum available faults

• Corrective action history to determine whether there had been any adverse operating trends

• Visual inspection to assess material condition, the presence of hazards, and consistency of installed equipment with design documentation and analyses

.1 Failure to Evaluate 480 Vac Motor Starters with Circuit Breaker Trip Settings Higher than

Manufacturers Specifications

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, involving the failure to evaluate 480 Vac combination motor starters with instantaneous magnetic circuit breaker trip current settings higher than their manufacturers' specifications.

Description.

The 480 Vac combination motor starters, which are used in motor control centers, contain an instantaneous magnetic circuit breaker, contactor, and thermal overload relay. The thermal overload relay senses excessive current due to motor overloads and failures to start and responds by signaling the contactor to open in order to protect the motor, components of the combination motor starter, and downstream cables and containment penetrations against excessive heating due to overcurrent conditions. If properly coordinated with the thermal overload setting, the instantaneous magnetic circuit breaker protects the combination starter components and downstream cables, and penetrations from downstream faults. Calculation 366A-DC, Molded Case Circuit Breakers and Thermal Overload Relays, Appendix 9, includes the following precaution from a Cutler Hammer vendor document: WARNING - To maintain overcurrent, short circuit, and ground fault protection, the manufacturers instructions for selection of the heater pack and setting of the instantaneous trip circuit breaker (current interrupter) must be followed. Other Cutler Hammer documents provide more specific setting instructions for the instantaneous magnetic circuit breakers to coordinate with the thermal overload relay setting, such as no higher than 13 times the motor full load amp ratings.

Trip settings of the vital instantaneous magnetic circuit breakers in combination starters are documented and analyzed in calculation 195B-DC, Evaluation of Molded Case Circuit Breaker Settings for 460VAC Class 1E Motors. Many of those breakers were set higher than the limits specified by their manufacturers. This lack of compliance with manufacturers setting instructions could result in downstream faults causing damage to the combination starter components, fire in the motor control center cubicle, spurious tripping of the entire motor control center, or thermal damage to cables and containment penetrations. The licensee had no analysis to demonstrate that these vulnerabilities do not exist.

Analysis.

The team determined the failure to evaluate 480 Vac combination motor starters with instantaneous magnetic circuit breaker trip current settings higher than their manufacturers' specifications was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, improper motor starter breaker trip settings could result in a fire in the motor control center cubicle, damage to motor starter components, spurious tripping of the entire motor control center, or lack of protection for downstream components during fault conditions. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding did not have a cross-cutting aspect because the most significant causal factor of the performance deficiency did not reflect current licensee performance.

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, which states, in part, The design control measures shall provide for verifying or checking the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program. Contrary to the above, prior to September 10, 2013, the licensee failed to verify or check the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.

Specifically, the licensee failed to verify the design of 480 Vac combination motor starter instantaneous magnetic circuit breakers settings, by the use of alternate or simplified calculational methods, for those breakers whose settings are higher than their manufacturers' specifications, as documented in calculation 195B-DC, MCCB Settings for 460VAC Class 1E Motors, to provide the required level of protection and ensure that certain failures that could be caused by sustained fault currents below the circuit breaker trip setting would not occur. In response to this finding, the licensee conducted a preliminary evaluation of some of the affected equipment and concluded that sustained fault currents below the trip settings are unlikely. This finding was entered into the licensee's corrective action program as Notification 50838071. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy: NCV 05000275/2016007-01 and 05000323/2016007-01, Failure to Evaluate 480 Vac Motor Starters with Circuit Breaker Trip Settings Higher than Manufacturers Specifications.

.2 Failure to Promptly Correct the Lack of Design Verification of 460 Vac Motors at

Maximum Allowable Frequency

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, involving the failure to correct the lack of design verification of 460 Vac motors at maximum allowable frequency when powered from the emergency diesel generators.

Description.

Technical specification surveillance requirements 3.8.1.2, 3.8.1.7, 3.8.1.11, 3.8.1.12, 3.8.1.15, and 3.8.1.20 allow a maximum emergency diesel generator frequency of 60.8 Hz. Increased frequency of a motor power supply causes a faster motor speed and increases the brake horsepower of the driven equipment. Motors that operate at or near their thermal capability limit at 60 Hz could overheat or trip on overcurrent when operating at a higher frequency.

Procedure OM7.ID1, Problem Identification and Resolution, provides instructions on the timeliness of problem resolution in Section 5.3. The procedure specifies the timeframe in calendar days within which actions should be completed from the time the action is generated. The timeframe for corrective actions from apparent cause evaluations is 180 days, and the timeframe for a preliminary plan for resolution is 30 days.

On July 31, 2013, the licensee completed an apparent cause evaluation under Notification 50573621 to address Non-cited Violations05000275/2013007-02 and 05000373/2013007-02 documented in the 2013 component design bases inspection report regarding the effect of maximum allowable emergency diesel generator voltage on the auxiliary feedwater pump motors. The licensees corrective actions in response to these non-cited violations identified the need to perform an extent of condition review for all vital alternating current motors in Task #5. The apparent cause evaluation stated, As a result the scope of Notification 50572850 has increased to include an extent of condition which applies to all ESF motors that have a BHP loading greater than their name plate rating. However, the associated corrective action task did not include all engineered safety feature (ESF) motors as described in the apparent cause evaluation, but limited the review to 4 kV motors (i.e., not 460 Vac motors).

In addition, on December 17, 2015, the licensee issued the DCPP 2016 Component Design Basis Inspection (CDBI) Self-Assessment report, which identified that, for 460 Vac motors, a documented Engineering evaluation of Class 1E motor heating when operating at 60.8 Hz via a DG powered vital bus should be prepared. Although Notification 50826105 was initiated on December 17, 2015, to address this issue, an action to perform the technical motor evaluation had not been initiated prior to the teams inquiry.

Analysis.

The team determined the failure to correct the lack of design verification of 460 Vac motors at maximum allowable frequency when powered from the emergency diesel generators was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, operation of 460 Vac motors above their rated or analyzed maximum allowable frequencies could result in motor overheating or a trip of the thermal overload relays. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green)because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of problem identification and resolution associated with evaluation because the licensee failed to ensure that the organization thoroughly evaluated issues to ensure that resolutions address causes and extent of conditions [P.2].

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, which states, in part, Measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected. Contrary to the above, prior to March 16, 2016, the licensee failed to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances were promptly identified and corrected. Specifically, the licensee failed to assure that the lack of design verification of 460 Vac motors, which could be overloaded at the maximum allowable diesel generator frequency, was promptly corrected after having been identified in a 2013 apparent cause evaluation and again in a 2015 self-assessment as documented in Notifications 50572850 and 50826105, respectively. In response to this finding, the licensee performed a preliminary evaluation of the affected 460 Vac motors and concluded that operation at maximum emergency diesel generator frequency would not cause them to overheat or trip on overcurrent.

This finding was entered into the licensee's corrective action program as Notifications 50835699 and 50838988. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy: NCV 05000275/2016007-02 and 05000323/2016007-02, Failure to Promptly Correct the Lack of Design Verification of 460 Vac Motors at Maximum Allowable Frequency.

.2.4 125 Volt Distribution Panel and Bus 2-2

a. Inspection Scope

The team reviewed the updated final safety analysis report, design basis documents, the current system health report, selected drawings, maintenance and test procedures, and condition reports associated with 125 Volt Distribution Panel and Bus 2-2 to ensure design basis requirements and specifications were met. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Calculations for electrical distribution system loading, voltages, and maximum short-circuit levels to evaluate the adequacy of the distribution panel bus and breakers to carry anticipated loads under limiting conditions

• Protective device settings and circuit breaker ratings to confirm adequate selective protection and coordination of connected equipment during worst-case short circuit conditions and to withstand and interrupt maximum available faults

• Corrective action history to determine whether there had been any adverse operating trends

• Visual inspection to assess material condition, the presence of hazards, and consistency of installed equipment with design documentation and analyses

b. Findings

Failure to Ensure Safety-Related Alternating Current and Direct Current Equipment Functionality at Maximum Allowable Voltages

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, involving the failure to evaluate operation of 125 Volt direct current

(dc) and 480 and 120 Volt alternating current

(ac) equipment at maximum allowable voltages (two examples).

Description.

Example 1: Equipment is designed and rated by its manufacturers to withstand supply voltages within a limited range. Procedure OP J-9:IV, Performing a Battery Equalizing Charge, specified an equalizing voltage of approximately 138 Vdc, and design criterion memorandum S-67, 125V/250V Volt Direct Current System, specified a maximum equalizing voltage of 139.8 Vdc, on nominally 125 Vdc systems, without an analysis to ensure that safety-related direct current equipment would not be adversely affected at the equalizing voltage level. However, the licensee had not performed a comprehensive review to verify or check that the maximum voltage to which vital dc equipment would be exposed during battery equalizing, which could be as high as 139.8 Vdc, was within the equipment maximum voltage ratings or that the equipment had been analyzed to function above its rated voltage limits. In response to the teams inquiry, the licensee performed a preliminary evaluation of the condition and determined that some of the dc equipment had maximum voltage ratings that were less than 139.8 Vdc, but that it was unlikely that they had been damaged due to exposure to voltages above their ratings.

Example 2: Equipment is designed and rated by its manufacturers to withstand supply voltages within a limited range. On June 30, 1997, the licensee issued design change package E-050321, which increased the voltage of the vital 480 Vac buses by 2.5 percent. The design change package stated, The calculation performed by Duke Engineering and Services (358A-DC) detailed the acceptable voltages on all buses during normal operation, accident conditions, and plant shutdown.

Calculation 358A-DC, DCPP Unit 2 Load Flow, Short Circuit, and Transient Stability Calculation, established a maximum voltage acceptance criterion of 105.4 percent (506 Volt) for the 480 Volt buses. Units 1 and 2 Procedures STP I-1C, Routine Weekly Checks Required by Licenses, include voltage checks of vital 480 Vac buses to verify that the voltage does not exceed 126.33 Vac on the secondary of the potential transformers, which translates to a limit of about 506 Vac on the 480 Vac buses.

Calculation 357G-DC, Guidelines for Circuit Breaker Data Entered into ETAP Database, specified a maximum voltage of 508 Vac on the 480 Vac buses to maintain the credited circuit breaker interrupting ratings. Calculation 357A-DC, Units 1&2 Load Flow, Short Circuit, and Motor Starting, identifies, in section 3.1.6, a voltage limit of 511 Vac to avoid overvoltages on the 120 Vac control circuits.

Contrary to these established voltage limits, implementation of design change package E-050321 resulted in measured bus voltages that were sometimes as high as 528 Vac. These overvoltage conditions were justified in Procedure OP J-2:VIII, Guidelines for Reliable Transmission Service for DCPP, Section 5.4, which stated that they are acceptable based on several corrective action documents that it referenced.

The team reviewed the referenced notifications and determined that they lacked the rigor of a formal calculation and failed to address a number of vulnerabilities. Specifically, the licensee lacked analysis of allowable overvoltage conditions on induction motor rotor overheating, comprehensive review of non-motor maximum voltage ratings, consideration of additional voltage boosting at the 120 Vac level, derating of circuit breaker interrupting capacities, motor operated valve torque considerations, and exceedance of maximum voltages for which equipment was qualified.

Analysis.

The team determined the failure to evaluate operation of 125 Vdc and 480 and 120 Vac equipment at maximum allowable voltages was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the equipment performance attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, operation of equipment outside of its rated or analyzed maximum allowable voltages adversely affects the reliability and capability of that equipment required to perform safety-related functions.

In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6].

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, which states, in part, The design control measures shall provide for verifying or checking the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program. Contrary to the above, prior to February 10, 2016, the licensee failed to verify or check the adequacy of design, such as by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program. Specifically, the licensee failed to verify the design of

(1) equipment on the nominally 125 Vdc system at the maximum voltage specified in Procedure OP J-9:IV, Performing a Battery Equalizing Charge, and

(2) equipment on 480 Vac and 120 Vac vital buses at maximum voltages specified in Procedure OP J-2:VIII, Guidelines for Reliable Transmission Service for DCPP, by the use of alternate or simplified calculational methods, to ensure equipment functionality. In response to this finding, the licensee conducted a preliminary evaluation of the affected equipment and concluded that any past exposure to voltages above their maximum rating would not have caused a loss of functionality. This finding was entered into the licensee's corrective action program as Notifications 50834558, 50835906, 50835394, 50835945, 50835949, 50836376, 50836439, 50836638, 50836872, and 50836995. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy: NCV 05000275/2016007-03 and 05000323/2016007-03, Failure to Ensure Safety-Related Alternating Current and Direct Current Equipment Functionality at Maximum Allowable Voltages.

.2.5 4160 Volt Feeder Breaker 52HF10

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with 4160 Volt feeder breaker 52HF10. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component functional description, maintenance history, and corrective action program reports to verify the monitoring of potential degradation

• Component logic, schematic, and wiring diagrams

• Feeder breaker vendor manual and qualification document

• Calculations for electrical distribution, system load flow/voltage drop, short-circuit, cable sizing and routing, and electrical protection to verify that switchgear bus capacity and voltages remained within minimum acceptable limits

• Protective device settings and circuit breaker ratings to ensure adequate selective protection coordination of connected equipment during worst-case short circuit conditions

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Results of completed preventative maintenance on breakers, including other breakers in the switchgear

b. Findings

Failure to Evaluate the Extent of Condition for a Degraded Condition on a Nonsafety- Related 4160 Vac Breaker

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, involving the failure to evaluate the impact of a cracked holding pawl identified on a nonsafety-related 4160 Vac SF6 breaker on additional safety-related 4160 Vac SF6 breakers.

Description.

Feeder circuit breaker 52HF10 is a 1200 A, 4160 Vac SF6 breaker.

Although 1200 A and 2000 A 4160 Vac SF6 circuit breakers were procured safety-related, some of their applications are classified as nonsafety-related. These breakers are mostly used in Units 1 and 2 4160 Vac switchgear buses, D and E, and safety-related switchgear, buses F and G.

The team reviewed corrective actions associated with the 4160 Vac SF6 breakers and observed that, on October 8, 2015, Notification 50809805 documented corrective actions associated with a cracked holding pawl on nonsafety-related 4160 Vac SF6 breaker 52HD10. As a corrective action, the licensee promptly removed the part and replaced it with a spare, but failed to review the impact of the condition on safety-related breakers. Specifically, although breaker 52HD10 is used in a nonsafety-related application, it was procured as safety-related and is of the same make and model as the safety-related 4160 Vac SF6 breakers.

The licensee failed to review Notification 50809805 and implement corrective actions in accordance with Procedure OM7.ID1, Problem Identification and Resolution.

Section 5.2.4.b.2, states that ---ensure positive contact is made with WCSFM to perform extent of condition if problem could adversely impact safety ---- or the ability of equipment to perform its intended licensing and or design function. Contrary to that provision, the licensee failed to recognize that the problem associated with the 4160 Vac nonsafety-related SF6 breaker could impact the ability of other safety-related breakers to perform their intended safety function and, as such, perform an extent of condition on safety-related 4160 Vac SF6 breakers due to the cracked holding pawl on the nonsafety-related 4160 Vac SF6 breaker, which was procured as quality equipment and, similar in make and model, to the safety related 4160 Vac SF6 breakers.

Analysis.

The team determined the failure to evaluate the impact of a cracked holding pawl identified on a nonsafety-related 4160 Vac SF6 breaker on additional safety-related 4160 Vac SF6 breakers was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the equipment performance attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the 4160 Vac breaker with the cracked holding pawl was procured as safety-related; therefore, the condition extends to safety-related 4160 Vac breakers of the same make and model and potentially adversely affects the ability to perform their safety function. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with conservative bias because the licensee failed to ensure that individuals used decision making-practices that emphasized prudent choices

[H.14].

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, which states, in part, Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Contrary to the above, in October of 2015, the licensee failed to accomplish activities affecting quality prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstance in accordance with these instructions, procedures, or drawings.

Specifically, the licensee failed to evaluate the extent of condition of a cracked holding pawl on a nonsafety-related 4160 Vac SF6 breaker, which was procured as safety-related, in accordance with Procedure OM7.ID1, Problem Identification and Resolution, when the failure of the component could adversely impact safety-related breakers of the same make and model. In response to this finding, the licensee is performing a procedure review to include steps to perform extent of condition analysis for unplanned nonsafety-related equipment issues that may also affect similar safety-related equipment. This finding was entered into the licensee's corrective action program as Notifications 50836859 and 50836689. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy: NCV 05000275/2016007-04 and 05000323/2016007-04, Failure to Evaluate the Extent of Condition for a Degraded Condition on a Nonsafety-Related 4160 Vac Breaker.

.2.6 4160 Volt / 480 Volt Transformer 2F

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with the 4160 Volt /

480 Volt transformer 2F. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Load tap changer design and temperature sensor monitor

• Component functional description, protection, logic and schematic diagram and sizing calculation

• Calculations for electrical distribution, system load flow/voltage drop, short-circuit, cable de-rate for load center transformer 2F, and electrical protection to verify that 480 Vac bus capacity and voltages remained within minimum acceptable limits

• Protective device settings and circuit breaker 52HF10 ratings to ensure adequate selective protection coordination of connected equipment during worst-case short circuit conditions

• Procedures for transformer maintenance, surveillances, inspection, and testing to compare maintenance practices against industry and vendor guidance; including the cable and insulation aging management program

• Results of completed preventative maintenance on transformer and supply breaker 52HF10, including breaker tracking

• Vendor manual and vendor recommended preventive maintenance requirements

b. Findings

No findings were identified.

.2.7 Containment Fan Cooler Unit 2-5

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with containment fan cooler unit 2-5. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Surveillances of containment air flow

• Modifications to the containment fan cooler unit back-draft damper

• Technical specifications and bases documents

• Vendor documentation

• External cleaning processes of the fan cooler units

• Chemistry control surveillances and test results of component cooling water system water with respect to system corrosion and containment fan cooler fouling requirements

• Piping and instrumentation diagrams

• System operating instructions

• Component one-line and control wiring diagram, cable schedule and cable routing for the fan motor

• Component fan motor cable sizing and routing for the fan motor and brake horsepower calculation

• Calculations for electrical distribution, system load flow/voltage drop, short-circuit, and electrical protection to verify that bus capacity and voltages remained within minimum acceptable limits

• Protective device settings and circuit breaker ratings for fan motor to ensure adequate selective protection coordination of connected equipment during worst-case short circuit conditions

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance; including the cable aging management program

b. Findings

No findings were identified.

.2.8 Auxiliary Saltwater Pump 1-1

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, modifications, vendor technical manual and condition reports associated with auxiliary saltwater pump 1-1. The team also performed walk downs and conducted interviews with system engineering personnel and inservice testing program personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Net positive suction head calculations, including elevated ultimate heat sink temperatures and varying tidal conditions, hydraulic balancing calculations to verify that the pump will be able to perform its functions during normal and accident conditions

• Modification to upgrade the pump to a larger impeller and the hydraulic effects on the system and pump

• Test trends for the last three years to verify that the pump has been operating in the desired range and is operationally ready, as well actions taken to correct any deficient conditions identified during tests

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Schematic diagrams to confirm the motor operation conformed to the design requirements

• Voltage drop calculations to determine whether the motor had adequate voltage for starting and running under degraded voltage conditions

• Cable sizes to determine whether the motor circuit cabling had adequate ampacity

• Maximum power demand of the pump to verify it was properly reflected in alternating current distribution system and diesel generator loading analyses, that the electrical protective devices were set appropriately, and that the motor thermal capability was not exceeded

b. Findings

No findings were identified.

.2.9 Auxiliary Saltwater Traveling Screen 1-7

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, selected drawings and calculations, maintenance and test procedures, modifications, vendor technical manual and condition reports associated with auxiliary saltwater travelling screen 1-7 and associated components. The team also performed walk downs and conducted interviews with system engineering personnel and operations personnel to ensure the capability of the auxiliary saltwater strainer components (e.g., screens, pumps, differential pressure instruments) to perform their desired design basis function under varying intake conditions. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Seismic calculation to verify the travelling screens are adequately supported during seismic and normal operating conditions, including considerations for maximum tidal conditions associated with tsunami conditions

• Intake management and alarm response procedures associated with the travelling screes to verify that changing conditions in the intake structure are managed adequately

• Modification to screen wash pumps and travelling screens to improve system performance

• Data collected from operator rounds to assure that the travelling screen system is operating acceptably and corrective actions are taken when system problems are encountered

• Material condition of this system to assure that the components get adequate consideration in the corrosive salt water environment

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Schematic diagrams to confirm that the screen and screen wash pump motor operation conformed to the design requirements

• Voltage drop calculations to determine whether the motor had adequate voltage for starting and running under degraded voltage conditions

• Cable sizes to determine whether the motor circuit cabling had adequate ampacity

b. Findings

No findings were identified.

.2.10 Charging Pump Suction Valves LCV-112B and LCV-112C

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with the charging pump suction valves. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of the related components to perform their desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Corrective action documents issued in the past five years to verify that repeat failures, and potential chronic issues, will not prevent the charging pump suction valves from performing their safety function

b. Findings

No findings were identified.

.2.11 Condensate Storage Tank

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with the condensate storage tank for Unit 2. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Corrective action documents issued in the past five years to verify that repeat failures, and potential chronic issues, will not prevent the condensate storage tank and associated components from performing their safety function

b. Findings

No findings were identified.

.2.12 Component Cooling Water Pump 2-2

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, modifications, vendor technical manual and condition reports associated with component cooling water pump 2-2. The team also performed walk downs and conducted interviews with system engineering personnel and inservice testing program personnel to ensure the capability of this component to perform its desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Net positive suction head calculations including elevated ultimate heat sink, hydraulic balancing calculations to verify that the pump will be able to perform its functions during normal and accident conditions

• Test trends for the last three years to verify that the pump has been operating in the desired range and is operationally ready, as well actions taken to correct any deficient conditions identified during tests

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Schematic diagrams to confirm the motor operation conformed to the design requirements

• Voltage drop calculations to determine whether the motor had adequate voltage for starting and running under degraded voltage conditions

• Cable sizes to determine whether the motor circuit cabling had adequate ampacity

• Maximum power demand of the pump to verify it was properly reflected in alternating current distribution system and diesel generator loading analyses, that the electrical protective devices were set appropriately, and that the motor thermal capability was not exceeded

b. Findings

No findings were identified.

.2.13 Component Cooling Water Heat Exchanger Inlet Valves FCV-602 and FCV-603

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with the component cooling water heat exchanger inlet valves FCV-602 and FCV-603. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function.

Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Calculations for air-operated valve design basis operating conditions, and weak-link analyses

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Air supply system and back up air accumulator system associated with valves FCV-602 and FVC-603

• System quarterly functional tests

• Technical specifications and bases documents

• Vendor manual for the valves

• Work orders and corrective action program documents

• Piping and instrumentation diagrams

• System operating instructions

b. Findings

No findings were identified.

.2.14 Pressurizer Power Operated Relief Valves PCV-445, PCV-456, and PCV-474

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with pressurizer power operated relief valves PCV-445, PCV-456, and PVC-474. The team also reviewed recent photographs of the valves and conducted interviews with system engineering personnel to ensure the capability of these components to perform their desired design basis function. Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Corrective action documents issued in the past five years to verify that repeat failures, and potential chronic issues, will not prevent the valves from performing their safety function

b. Findings

No findings were identified.

.2.15 Residual Heat Removal System Valves RHR-8701 and RHR-8702

a. Inspection Scope

The team reviewed the updated final safety analysis report, system description, design basis documents, the current system health report, selected drawings and calculations, maintenance and test procedures, and condition reports associated with residual heat removal system motor operated valves RHR-8701 and RHR-8702. The team also performed walkdowns and conducted interviews with system engineering personnel to ensure the capability of this component to perform its desired design basis function.

Specifically, the team reviewed:

• Component maintenance history and corrective action program reports to verify the monitoring of potential degradation

• Calculations for motor-operated valve design basis operating conditions, torque and thrust capabilities, and weak-link analyses

• Procedures for preventive maintenance, inspection, and testing to compare maintenance practices against industry and vendor guidance

• Surveillances pertaining to valve leakage requirements and test results

• System quarterly functional tests

• Technical specifications and bases documents

• Vendor documentation for installation, operation, and maintenance of the valves

• Work orders and corrective action program documents

• Piping and instrumentation diagrams

• System operating instructions

• Component one-line and control wiring diagram, cable schedule and cable routing for the valve motors

• Component motor cable sizing and routing for the valve motors and brake horsepower calculations

• Calculations for electrical distribution, system load flow/voltage drop, short-circuit, and electrical protection to verify that bus capacity and voltages remained within minimum acceptable limits

• Protective device settings and circuit breaker ratings to ensure adequate selective protection coordination of connected equipment during worst-case short circuit conditions

• Procedures for preventive maintenance, corrective actions, inspection, and testing to compare maintenance practices against industry and vendor guidance; including the cable aging management program

• Valve motor control power transformer and fuse sizing

b. Findings

No findings were identified.

.3.1 Inspection of NRC Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk

and the Operability of Offsite Power

a. Inspection Scope

The inspectors reviewed the licensee response to NRC Generic Letter 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power. The licensee's interface and coordination with the transmission system operator for plant voltage requirements and notification of the need for compensatory measures were reviewed. The inspectors also reviewed the capacity and capability of the 230 kV offsite power circuit to perform its required functions during anticipated operational occurrences and postulated accidents. The review included the ability of the load tap changing standby-startup transformers to automatically correct low voltage conditions prior to actuation of the degraded voltage relays.

.1 Failure to Evaluate the Voltage Effects of Limiting Design Basis Events on the 230 kV

Offsite Power Circuit

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, involving the failure to evaluate the voltage effects of a limiting design basis event with non-coincident reactor trip and engineered safety features actuation system signals on the 230 kV offsite power circuit.

Description.

The licensees updated final safety analysis report states in Section 8.2.1.2, The preferred power supply has sufficient capacity and capability to assure that:

(1) specified fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences, and

(2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. Calculation 359-DC, Determination of 230 kV Grid Capability Limits as DCPP Offsite Power Source, models the transient voltage effects of various design basis events and verifies that the resulting voltage depression is not so severe that it would result in loss of the 230 kV offsite power circuit due to an undervoltage trip. The calculation assumes a coincident engineered safety features actuation system signal and reactor trip signal. The engineered safety features actuation system signal initiates immediate automatic transfer of the vital buses from the auxiliary transformer to the standby startup transformer, but transfer of the non-vital buses to the standby startup transformer and tripping of the main generator is delayed for approximately 30 seconds after a reactor trip. However, the team reviewed the licensees accident analyses and observed that the reactor trip signal could also occur before the engineered safety features actuation system signal for steam generator tube rupture, steam line break, and small break loss-of-coolant accidents. Therefore, the transfer of vital and non-vital loads to the standby startup transformer and tripping of the main generator could coincide and the voltage effect on the vital buses could be more severe than the scenarios modeled in the calculation.

Analysis.

The team determined the failure to evaluate the voltage effects of a limiting design basis event with non-coincident reactor trip and engineered safety features actuation system signals on the 230 kV offsite power circuit was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to ensure adequate bus voltages as a result of a design basis event with non-coincident reactor trip and engineered safety features actuation system signals would result in a trip of the undervoltage relays and the loss of the preferred offsite power circuit. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6].

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, which states, in part, The 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 January 30, 2014, the licensee failed to verify or check 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. Specifically, the licensee failed to verify the design of the 230 kV preferred offsite power source, such as by the performance of design reviews or use of alternate or simplified calculational methods, by assuming in calculation 359-DC, Determination of 230 kV Grid Capability Limits as DCPP Offsite Power Source, that the reactor trip and engineered safety features actuation system signals are coincident in time for all postulated design basis events. However, the plant is designed such that, during some events, the signals are separate in time and would result in a greater vital bus voltage depression than analyzed. In response to this finding, the licensee conducted a preliminary evaluation and concluded that the current transmission grid conditions were such that the calculation criteria would be met in the event of a design basis event involving non-coincident reactor trip and engineered safety features actuation system signals.

This finding was entered into the licensee's corrective action program as Notification 50839137. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy:

NCV 05000275/2016007-05 and 05000323/2016007-05, Failure to Evaluate the Voltage Effects of Limiting Design Basis Events on the 230 kV Offsite Power Circuit.

.2 Failure to Translate Appropriate Load Tap Changer Timing Acceptance Criteria into

Periodic Tests

Introduction.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, involving the failure to translate appropriate load tap changer timing acceptance criteria into functional tests to ensure that design assumptions were being maintained.

Description.

The licensees updated final safety analysis report states in Section 8.2.1.2:

The preferred power supply has sufficient capacity and capability to assure that:

(1) specified fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences, and

(2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. Calculation 359-DC, 230 kV Grid Interface Requirements as a DCPP Offsite Power Source, includes simulations to verify that vital bus voltage transients during design basis events are automatically corrected by the standby startup transformer load tap changers to ensure that that the 230 kV offsite power circuit has the required capability (i.e., that it would not be lost due to an undervoltage trip). However, Unit 1 Procedure MP E-62.3, Tap Changer Functional Test for Standby-Startup Transformer 11, allows up to 16 seconds for three load tap changer step changes, but calculations 357A-DC, Unit 1 and 2 Load Flow, Short Circuit and Motor Starting Analysis, and 359-DC, 230 kV Grid Interface Requirements as a DCPP Offsite Power Source, credit a faster speed of 3.3 seconds per step. Most of the postulated cases require multiple load tap changer steps to achieve a voltage that exceeds the second level undervoltage relay voltage threshold. Margins between the calculated voltage recovery times and the second level undervoltage relay minimum time delay are discussed in calculation 359-DC, Section 9.1. For the bounding case, the calculated recovery time is 16.07 seconds versus a required recovery time of 16.09 seconds, so the design margin is only 0.02 seconds.

Analysis.

The team determined the failure to translate appropriate load tap changer timing acceptance criteria into functional tests to ensure that design assumptions were being maintained was a performance deficiency. The performance deficiency was more-than-minor, and therefore a finding, because it related to the design control attribute of the Mitigating Systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the load tap changer could meet its functional test acceptance criterion but not operate fast enough to restore vital bus voltages within the required time during design basis events, which would result in an undervoltage trip and loss of the preferred offsite power circuit. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated July 19, 2012, the finding screened as having very low safety significance (Green) because it was a design or qualification deficiency that did not represent a loss of operability or functionality; did not represent an actual loss of safety function of the system or train; did not result in the loss of one or more trains of non-technical specification equipment; and did not screen as potentially risk-significant due to seismic, flooding, or severe weather. This finding had a cross-cutting aspect in the area of human performance associated with design margins because the licensee failed to ensure that the organization operated and maintained equipment within design margins and that margins were carefully guarded and changed only through a systematic and rigorous process [H.6].

Enforcement.

The team identified a Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, which states, in part, Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished. Contrary to the above, prior to November 25, 2015, the licensee failed to include appropriate quantitative or qualitative acceptance criteria in instructions, procedures, and drawings for determining that important activities have been satisfactorily accomplished. Specifically, the licensee failed to include appropriate quantitative acceptance criteria in Procedure MP E-62.3, Tap Changer Functional Test for Standby-Startup Transformer 11, to ensure that the load tap changer speed for standby-startup transformer 11 was adequate to restore vital bus voltages to the required level during design basis events. In response to this finding, the licensee performed a preliminary evaluation of the condition and concluded that the most recently measured speed of the load tap changer was adequate to ensure that it would restore vital bus voltage within the required time. This finding was entered into the licensee's corrective action program as Notification 50839333. Because this finding was of very low safety significance and has been entered into the licensees corrective action program, this violation is being treated as a non-cited violation, consistent with Section 2.3.2.a of the NRC Enforcement Policy: NCV 05000275/2016007-06 and 05000323/2016007-06, Failure to Translate Appropriate Load Tap Changer Timing Acceptance Criteria into Periodic Tests.

.3.2 Inspection of NRC Information Notice 2007-36, Emergency Diesel Generator Voltage

Regulator Problems

a. Inspection Scope

The team reviewed the licensees evaluation of Information Notice 2007-36, Emergency Diesel Generator Voltage Regulator Problems, to verify the licensee performed an applicability review and took corrective actions, if appropriate, to address the concerns described in the information notice. This information notice discusses various failure associated with emergency diesel generator voltage regulators. The team verified that the licensees review adequately addressed the issues in the information notice.

b. Findings

No findings were identified.

.3.3 Inspection of NRC Information Notice 2012-06, Ineffective Use of Vendor Technical

Recommendations

a. Inspection Scope

The team reviewed the licensees evaluation of Information Notice 2012-06, Ineffective Use of Vendor Technical Recommendations, to verify the licensee performed an applicability review and took corrective actions, if appropriate, to address the concerns described in the information notice. This information notice discusses recent operating experience regarding ineffective use of vendor technical recommendations at U.S.

nuclear power plants. The team verified that the licensees review adequately addressed the issues in the information notice.

b. Findings

No findings were identified.

.3.4 Inspection of NRC Information Notice 2012-14, Motor-Operated Valve Inoperable due to

Stem-Disc Separation

a. Inspection Scope

The team reviewed the licensees evaluation of Information Notice 2012-14, Motor-Operated Valve Inoperable due to Stem-Disc Separation, to verify the licensee performed an applicability review and took corrective actions, if appropriate, to address the concerns described in the information notice. The team also reviewed enhancements to the licensees processes for verifying valve position and the affected procedures to assure that this key aspect of the information notice was considered. The team verified that the licensees review adequately addressed the issues in the information notice.

b. Findings

No findings were identified.

.3.5 Inspection of NRC Information Notice 2014-03, Turbine-Driven Auxiliary Feedwater

Pump Overspeed Trip Mechanism Issues

a. Inspection Scope

The team reviewed the licensees evaluation of Information Notice 2014-03, Turbine-Driven Auxiliary Feedwater Pump Overspeed Trip Mechanism Issues, to verify the licensee performed an applicability review and took corrective actions, if appropriate, to address the concerns described in the information notice. This information notice discusses recent operating experience related to improper adjustments of control mechanisms that led to inoperability of turbine-driven auxiliary feedwater pumps. The team reviewed several corrective action program documents and maintenance activities for physical inspection and measurement of the pump control mechanisms to address the concerns identified in the information notice. The team verified that the licensees review adequately addressed the issues in the information notice.

b. Findings

No findings were identified.

.4 Results of Reviews for Operator Actions

a. Inspection Scope

The team selected risk-significant components and operator actions for review using information contained in the licensees probabilistic risk assessment. This included components and operator actions that had a risk achievement worth factor greater than two or Birnbaum value greater than 1E-6.

For the review of operator actions, the team observed operators during simulator scenarios associated with the selected components as well as observing simulated actions in the plant.

The selected operator actions were:

• Scenario 1 was initiated by a spurious safety injection signal. The crews were required to stop centrifugal charging pump number 3, make a power operated relief valve available, restore instrument air to containment, and to establish normal letdown.

• Scenario 2 was initiated by a leak in the component cooling water system. The crews were required to locate and isolate the leak, which includes field actions, after receiving component cooling water surge tank makeup alarm.

b. Findings

No findings were identified.

OTHER ACTIVITIES

Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity

4OA2 Problem Identification and Resolution

The team reviewed actions requests and notifications associated with the selected components, operator actions and operating experience notifications. Any related findings are documented in prior sections of this report.

4OA6 Meetings, Including Exit

Exit Meeting Summary

On March 10, 2016, the inspectors presented the inspection results to Mr. James Welsch, Site Vice President, and other members of the licensee staff. On April 7, 2016, the NRC inspectors discussed the final results of this inspection with Mr. Robert Waltos, Acting Director, Engineering, and Mr. Thomas Baldwin, Director, Nuclear Site Services, and other members of the licensees staff. The licensee acknowledged the issues presented. The licensee confirmed that any proprietary information reviewed by the inspectors had been returned or destroyed.

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee Personnel

A. Heffner, NRC Interface, Regulatory Services

A. Peck, Director, Engineering Services

C. Basulto, Mechanical Engineer, Design Engineering

C. Ingram, Mechanical Engineer, Design Engineering

E. Tahlman, Electrical Engineer, Electrical Systems and Components

G. Reimers, Senior Consultant, Design Engineering

H. Garcia, Manager, CNO Support

H. Hamzehee, Manager, Regulatory Services

J. Loya, Manager, Quality Verification

J. Morris, Senior Advising Engineer

J. Nimick, Senior Station Director

J. Salazar, Engineer, Mechanical Systems

J. Welsch, Site Vice President

L. Orozco, Electrical Engineer, Design Engineering

L. Parker, STARS Regulatory Affairs Specialist

M. McCoy, NRC Interface, Regulatory Services

M. Sharp, Manager, Design Engineering

P. Gerfen, Director, Operation Services

R. Waltos, Acting Director, Engineering

T. Baldwin, Director, Nuclear Site Services

T. Stanton, Senior Engineer, Design Engineering

NRC Personnel

B. Tharakan, Senior Resident Inspector

J. Reynoso, Resident Inspector

LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED

Opened and Closed

05000275; NCV Failure to Evaluate 480 Vac Motor Starters with

05000373/2016007-01 Circuit Breaker Trip Settings Higher than Manufacturers Specifications (Section 1R21.2.3.b.1)

05000275; NCV Failure to Promptly Correct the Lack of Design

05000373/2016007-02 Verification of 460 Vac Motors at Maximum Allowable Frequency (Section 1R21.2.3.b.2)

05000275; NCV Failure to Ensure Safety-Related Alternating Current

05000373/2016007-03 and Direct Current Equipment Functionality at Maximum Allowable Voltages (Section 1R21.2.4.b)

Attachment

Opened and Closed

05000275; NCV Failure to Evaluate the Extent of Condition for a

05000373/2016007-04 Degraded Condition on a Nonsafety-Related 4160 Vac Breaker (Section 1R21.2.5.b)

05000275; NCV Failure to Evaluate the Voltage Effects of Limiting

05000373/2016007-05 Design Basis Events on the 230 kV Offsite Power Circuit (Section 1R21.3.1.b.1)

05000275; NCV Failure to Translate Appropriate Load Tap Changer

05000373/2016007-06 Timing Acceptance Criteria into Periodic Tests (Section 1R21.3.1.b.2)