IR 05000282/2013007
| ML13142A461 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/22/2013 |
| From: | Ann Marie Stone NRC/RGN-III/DRS/EB2 |
| To: | Jeffery Lynch Northern States Power Co |
| Benny Jose | |
| References | |
| IR-13-007 | |
| Download: ML13142A461 (41) | |
Text
May 22, 2013
SUBJECT:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2; NRC COMPONENT DESIGN BASES INSPECTION AND TRIENNIAL HEAT SINK INSPECTION REPORT 05000282/2013007; 05000306/2013007
Dear Mr. Lynch:
On April 19, 2013, the U.S. Nuclear Regulatory Commission (NRC) completed a Component Design Bases Inspection (CDBI) and the incomplete portion of 2012 Triennial Heat Sink Performance Inspection at your Prairie Island Nuclear Generating Plant. The enclosed report documents the inspection findings, which were discussed on April 19, 2013, with you and other members of your staff.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.
Based on the results of this inspection, three NRC-identified findings of very low safety significance were identified. The findings involved violations of NRC requirements. However, because of their very low safety significance, and because the issues were entered into your Corrective Action Program, the NRC is treating the issues as Non-Cited Violations (NCVs) in accordance with Section 2.3.2 of the NRC Enforcement Policy. No cross-cutting aspects were assigned to these findings.
If you contest the subject or severity 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 Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001, with a copy to the Regional Administrator, Region III; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspector at the Prairie Island Nuclear Generating Plant. In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records System (PARS) component of NRC's Agencywide Documents Access and Management System (ADAMS), accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Ann Marie Stone, Chief Engineering Branch 2 Division of Reactor Safety Docket Nos. 50-282 and 50-306 License Nos. DPR-42 and DPR-60
Enclosure:
Inspection Report 05000282/2013007; 05000306/2013007 w/Attachment: Supplemental Information
REGION III==
Docket Nos:
50-282 and 50-306 License Nos:
05000282/2013007; 05000306/2013007 Licensee:
Northern States Power Company, Minnesota Facility:
Prairie Island Nuclear Generating Plant, Units 1 and 2 Location:
Welch, MN Dates:
March 18, 2013, through April 19, 2013 Inspectors:
B. Jose, Senior Engineering Inspector, Lead I. Hafeez, Engineering Inspector, Electrical N. Féliz Adorno, Engineering Inspector, Mechanical R. Walton, Senior Operations Inspector
C. Baron, Mechanical Contractor
A. Della Greca, Electrical Contractor Approved by:
Ann Marie Stone, Chief Engineering Branch 2
Division of Reactor Safety
i
SUMMARY OF FINDINGS
IR 05000282/2013007; 05000306/2013007; 03/18/2013 - 04/19/2013; Prairie Island Nuclear
Generating Plant, Units 1 and 2; Component Design Bases Inspection (CDBI) and Triennial Heat Sink Performance Inspection.
The inspection was a 3-week onsite baseline inspection that focused on the design of components and ultimate heat sink performance. The inspection was conducted by regional engineering inspectors and two consultants. Three findings of very low significance (Green)were identified by the inspectors. All three of these findings were considered Non-Cited Violations (NCVs) of NRC regulations. The significance of inspection findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process, dated June 2, 2011. Cross-cutting aspects are determined using IMC 0310, Components within the Cross-Cutting Areas, dated October 28, 2011. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy dated January 28, 2013. The NRCs program for overseeing the safe operation of commercial nuclear power reactors are described in NUREG-1649, Reactor Oversight Process, Revision 4, dated December 2006.
NRC-Identified
and Self-Revealed Findings
Cornerstone: Mitigating Systems
- Green.
The inspectors identified a finding of very low safety significance and associated NCV of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the failure to correctly model the effects of the strainers and isolation valves in the cooling water flow calculations. Specifically, calculations did not account for the strainer backwash differential pressure setpoint and leakage of the ring header isolation valves. This finding was entered into the licensees Corrective Action Program (CAP) to revise the affected calculations and evaluate the need for additional corrective actions.
The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of design control and affected the cornerstone objective of ensuring the availability, reliability, and capability of the cooling water system to respond to initiating events to prevent undesirable consequences. Specifically, the magnitude of the errors required the licensee to re-perform the cooling water flow calculations to assure the system would be able to meet the flow demand. The finding screened as of very low safety significance (Green)because it did not result in the loss of operability or functionality. Specifically, the licensee removed conservatisms from the calculations, added the maximum allowable strainer loss, and reasonably determined that the system remained operable. In addition, the licensee determined the isolation valves had not experienced gross leakage. The inspectors did not identify a cross-cutting aspect associated with this finding because it did not reflect current performance due to the age of the performance deficiency. (Section 1R07.1.b(1))
- Green.
The inspectors identified a finding of very low safety significance and associated NCV of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the failure to review the suitability of the cooling water strainers under post-seismic flow conditions.
Specifically, the licensee did not recognize the post-seismic hydraulic parameters were greater than the vendor design values for the strainers. This finding was entered into the licensees CAP to evaluate the condition and initiate further actions as necessary.
The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of design control and affected the cornerstone objective of ensuring the availability, reliability, and capability of the cooling water system to respond to initiating events to prevent undesirable consequences. Specifically, flow rates higher than design values may impair the cleaning function and cause damage to the strainers affecting the capability of the cooling water system to perform its accident mitigating function. The finding screened as of very low safety significance (Green) because a detailed risk evaluation determined the core damage frequency of this finding was 1.9E-7/yr. The inspectors did not identify a cross-cutting aspect associated with this finding because it did not reflect current performance due to the age of the performance deficiency. (Section 1R07.1.b(2))
- Green.
The inspectors identified a finding of very low safety significance and associated NCV of 10 CFR Part 50, Appendix B, Criterion XI, Test Control, for the failure to demonstrate the ability to transfer diesel fuel oil from any Unit 1 fuel oil storage tank to any Unit 1 emergency diesel generator or diesel driven cooling water pump day tank.
Specifically, the licensee did not intentionally or periodically verify the ability to transfer fuel between the Unit 1 tanks as credited in the Technical Specification Basis and Updated Safety Analysis Report. This finding was entered into the licensees CAP to test the affected flow paths.
The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of equipment performance and affected the cornerstone objective of ensuring the availability, reliability, and capability of the Unit 1 emergency diesel generators and diesel drivel cooling water pumps to respond to initiating events to prevent undesirable consequences.
Specifically, the failure to verify the fuel oil transfer capability did not ensure the minimum fuel oil volume required by Technical Specifications could be supplied to these systems to support their accident mitigating function. The finding screened as of very low safety significance (Green) because it did not result in the loss of operability or functionality. Specifically, the licensee reviewed the recent history of the affected piping system and determined the affected flow paths were successfully used in 2010 and 2011 providing reasonable assurance the flow paths were available. The inspectors did not find an applicable cross-cutting aspect, which represented the underlying cause of this performance deficiency; therefore, no cross-cutting aspect was assigned.
(Section 1R21.3.b(1))
Licensee-Identified Violations
No violations were identified.
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R07 Heat Sink Performance
.1 Triennial Review of Heat Sink Performance
a. Inspection Scope
The triennial review of the Heat Sink Performance was initiated in August 2012. As documented in Inspection Report 05000282/2012004; 05000306/2012004 (ML12311A394), the inspectors completed their review of the 21 and 22 component cooling water heat exchangers. During this period, the inspectors completed the remainder of the inspection procedure objectives as noted below.
The inspectors verified the performance of ultimate heat sink (UHS) and cooling water (CL) system (which was the safety-related service water system) and their subcomponents such as piping, intake screens, pumps, and valves by tests or other equivalent methods, to ensure availability and accessibility to the in plant CL loads.
The inspectors reviewed the licensees performance testing of the CL System and UHS results. This included the review of the licensees performance test results for key components and CL flow balance calculations. In addition, the inspectors compared flow balance calculations to system configuration and flow assumptions during design basis accident conditions. The inspectors also reviewed isolation during design basis events, consistency between flow balance calculations and design basis leakage rate assumptions, and performance of risk significant non-safety-related functions.
The inspectors performed a system walkdown on the CL system to verify the licensees assessment on structural integrity. In addition, the inspectors reviewed available licensees testing and inspection results, licensee's disposition of any active through wall pipe leaks, and the history of through wall pipe leakage to identify any adverse trends since the last NRC inspection. For buried or inaccessible piping, the inspectors reviewed the licensee's pipe testing, inspection, or monitoring program to verify structural integrity, and assessed licensees identification and disposition of leakage or degradation. The inspectors also reviewed the periodic piping inspection program for detection and correction of protective coating, corrosion, and erosion. The inspectors assessed licensees monitoring and resolution of adverse trends for the deep draft vertical pumps by reviewing the operational history and in-service testing (IST) vibration monitoring results.
In addition, the inspectors reviewed condition reports related to heat sink performance issues to verify the licensee had an appropriate threshold for identifying issues and to evaluate the effectiveness of the corrective actions.
These inspection activities (inspection of the UHS and the 21/22 component cooling water heat exchangers as previously documented) constituted two heat sink inspection samples as defined in Inspection Procedure (IP) 71111.07-05. The documents that were reviewed during this inspection period are included in the Attachment to this report.
b. Findings
- (1) Failure to Verify the Adequacy of Cooling Water System Design
Introduction:
A finding of very low safety significance and associated Non-Cited Violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, Design Control, was identified by the inspectors for the failure to correctly model the effects of the strainers and isolation valves in the CL flow calculations. Specifically, calculations did not account for the strainer backwash differential pressure setpoint and leakage of the CL isolation valves.
Description:
The inspectors noted CL flow calculations, ENG-ME-404, Loss of Offsite Power with One CL Pump; ENG-ME-310, Emergency Intake Line - Post Seismic Minimum Flow; and ENG-ME-474; CL System Operations during Loss of Coolant Accident (LOCA) and Post LOCA Recirculation; contained the following non-conservative errors:
- The calculations did not account for the strainer pressure losses due to the maximum allowed debris build-up. Specifically, there were two strainers upstream of each CL header to remove particulates from the cooling water before it entered the headers.
Each strainer had an automatic backwash mechanism to clear debris from the strainers to prevent loss of flow due to debris build-up. This automatic backwash mechanism was programmed to initiate when a differential pressure of 4 pounds per square inch differential (psid) was sensed across the strainers. However, the strainer pressure drops used by the hydraulic calculations were based on pressure drop and flow values determined during model benchmarking and these values were lower than the 4 psid setpoint. The inspectors were concerned because using lower pressure drop values overestimated the flow supply of the CL System. As a result, the licensee evaluated the most limiting scenario for minimum required CL flow supply (i.e., ENG-ME-474) using a pressure drop value that bounded the backwash setpoint and determined the error resulted in negative analytical margin.
The licensee captured the inspectors concerns in their Corrective Action Program (CAP) as Action Request (AR) 1376876. The licensee revised calculation ENG-ME-474 by removing some analytical conservatism to provide reasonable assurance of operability. The corrective action considered at the time of this inspection was to revise the affected calculations to account for strainer automatic backwash setpoint.
- The calculations did not account for isolation valve leakage. Specifically, CL header isolation valves MV-32034, MV-32035, MV-32036, MV-32037, MV-32144, and MV-32159 have the safety-related function to close and split the CL ring header into two isolated headers following a safety injection signal. These valves were not tested for leakage because they were classified as Category B valves. Procedure H10.1, American Society of Mechanical Engineers [ASME] Inservice Testing Program, defined Category B valves as those for which seat leakage in the closed position was inconsequential for fulfillment of their design basis function. However, calculation ENG-ME-474 did not assume any leakage through these valves. The inspectors were concerned because the low analytical margin of ENG-ME-474 meant leakage through these valves was not inconsequential and Updated Safety Analysis Report (USAR) 10.4.1, Cooling Water System, credited each header to supply the cooling water requirements for long-term cooling of both units with an accident having occurred in one unit.
The licensee captured the inspectors concerns in their CAP as AR 1378690. The licensee established reasonable assurance of operability because a review of the recent history of the valves did not indicate gross leakage and pump IST results showed the pumps were operating above the design established in the hydraulic analysis. The corrective action considered at the time of this inspection was to benchmark other utilities to determine how to address CL header isolation valve leakage.
Analysis:
The inspectors determined the failure to correctly model the effects of the strainers and isolation valves in CL hydraulic calculations was contrary to 10 CFR Part 50, Appendix B, Criterion III, Design Control, and was a performance deficiency.
The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of design control and affected the cornerstone objective of ensuring the availability, reliability, and capability of the cooling water system to respond to initiating events to prevent undesirable consequences. Specifically, the magnitude of the errors required the licensee to re-perform the cooling water flow calculations to assure the system would be able to meet the flow demand.
The inspectors determined the finding could be evaluated using the Significance Determination Process (SDP), Attachment 0609.04, Initial Characterization of Findings. Because the finding impacted the Mitigating Systems cornerstone, the inspectors screened the finding through IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, using Exhibit 2, Mitigating Systems Screening Questions. The finding screened as of very low safety significance (Green)because it did not result in the loss of operability or functionality. Specifically, the licensee removed conservatisms from the calculations, added the maximum allowable strainer loss, and reasonably determined the system remained operable. In addition, the licensee determined the isolation valves had not experienced gross leakage.
The inspectors did not identify a cross-cutting aspect associated with this finding because it did not reflect current performance due to the age of the performance deficiency.
Enforcement:
10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, design control measures shall provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.
Contrary to the above, as of April 19, 2013, the design control measures failed to verify the adequacy of the design of the CL system. Specifically, CL hydraulic calculations did not verify the performance of the system was adequate when operating with gross leakage through the isolation valves and maximum allowed strainer debris loading. The licensee is still evaluating its planned corrective actions. However, the inspectors determined the continued non-compliance does not present an immediate safety concern because the licensee reasonably demonstrated system performance is higher than predicted by the affected analyses. Because this violation was of very low safety significance and was entered into the licensees CAP as AR1376876 and AR1378690, this violation is being treated as an NCV Violation, consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000282/2013007-01; 05000306/2013007-01, Failure to Verify the Adequacy of Cooling Water System Design).
- (2) Failure to Review the Suitability of the CL Strainers Under Post-Seismic Flow Conditions
Introduction:
A finding of very low safety significance and associated NCV Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, was identified by the inspectors for the failure to review the suitability of the CL strainers under post-seismic flow conditions. Specifically, post-seismic hydraulic parameters were greater than the vendor design values for the strainers.
Description:
Section 10.4.1 of the Updated Safety Analyses Report (USAR), Cooling Water System, stated the safety-related portions of the CL system were designed to withstand a seismic event. It further stated several runs of non-safety-related piping connected to the safety-related piping had not been analyzed to withstand seismic loads.
The USAR also stated continued functionality of the CL system following a seismic event was demonstrated using hydraulic analysis techniques that assumed a complete break of a non-seismic pipe at the worst-case location. This analysis was documented in calculation ENG-ME-611, Evaluation of CL System Response Following a Seismic Event, which included seismic scenarios with one CL strainer isolated. The CL system had two strainers upstream of each CL header to remove particulates from the cooling water before it entered the headers. Each pair of strainers was installed in parallel to allow for the isolation of one strainer while maintaining the operability of the associated CL header and supported trains of safety-related loads. Calculation ENG-ME-611 determined the postulated pipe break would result in system flow rates up to 19,103 gallons per minute (gpm), which would cause differential pressures of up to 18.78 psid across the non-isolated strainer. However, the inspectors noted the strainer vendor manual included a caution stating the differential pressure must not exceed 10 psid and that higher values may impair the cleaning function and cause malfunction of the equipment.
As a result of the inspectors questions, the licensee contacted the strainer vendor for additional information. The vendor stated the differential pressure warning was associated with the automatic backwash performance of the strainers. Specifically, if the 10 psid value is exceeded, solids could become tightly packed into the strainer tubes requiring manual cleaning. Manual cleaning would require the opening of the affected strainer and the removal from service of the affected CL header since the other strainer would be already isolated during the post seismic scenario considered in the calculation described above. Furthermore, the vendor stated the predicted post-seismic flow rates were greater than the strainers design value of 13,000 gpm which had the potential to cause strainer damage.
The licensee captured the inspectors concerns in their CAP as AR 1378695. The licensees immediate action was to initiate a standing order for operations to be aware the operability of a CL header is questionable with one strainer isolated. In addition, a historical review determined the total duration of one strainer isolation for the last year was 337.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />. This duration was used by the Senior Reactor Analyst (SRA) in determining the significance of this finding. The corrective actions considered at the time of this inspection were to evaluate the condition and initiate further actions as necessary.
Analysis:
The inspectors determined the failure to review the suitability of the CL strainers under post-seismic flow conditions was contrary to 10 CFR Part 50, Appendix B, Criterion III, Design Control, and was a performance deficiency.
The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of design control and affected the cornerstone objective of ensuring the availability, reliability, and capability of mitigating systems to respond to initiating events to prevent undesirable consequences. Specifically, flow rates higher than design values may impair the cleaning function and cause damage to the CL strainers. This condition would have the potential to adversely affect the CL systems ability to provide the required strained water to downstream safety-related components.
The inspectors performed a significance screening of this finding using the guidance provided in IMC 0609, "Significance Determination Process," Appendix A, "The Significance Determination Process (SDP) for Findings At-Power." The inspectors determined the finding required a detailed risk evaluation in accordance with Exhibit 2, "Mitigating Systems Screening Questions," and Exhibit 4, "External Event Screening Questions. The Senior Reactor Analyst (SRA) performed the risk evaluation using the NRC Risk Assessment Standardization Project Handbook and a licensee analysis titled Turbine Building HELB [high energy line break]/Internal Flooding Significance Determination Process, which was from a separate issue, and determined the frequency of a seismic event and failure of the supply line to be 4.5E-6/yr. The SRA assumed the 337.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> of one strainer operation of the previous 12-months was representative of an average year at Prairie Island and that core damage would result.
Thus, the core damage frequency (CDF) for this finding was determined to be 1.9E-7/yr.
This value also represents the bounding CDF. In addition, the SRA used IMC 0609, Appendix H, Containment Integrity Significance Determination Process, and determined the risk significance of the finding due to Large Early Release Frequency was insignificant because it involved a non-dominant core damage sequence.
Therefore, the SRA concluded the total risk increase to the plant due this finding is of very low safety significance (Green).
The inspectors did not identify a cross-cutting aspect associated with this finding because it did not reflect current performance due to the age of the performance deficiency.
Enforcement:
10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, measures shall also be established for the selection and review for suitability of application of materials, parts, equipment, and processes that are essential to the safety-related functions of the structures, systems and components.
Contrary to the above, as of April 19, 2013, the licensee failed to review for suitability of application of equipment essential to the safety-related functions of the CL system.
Specifically, post-seismic hydraulic parameters exceeded the original CL strainer design specification values when one strainer was isolated. The licensee is still evaluating its planned corrective actions. However, the inspectors determined the continued non-compliance does not present an immediate safety concern because the licensee initiated a standing order for operations to be aware the operability of a CL header is questionable when one strainer is isolated. Because this violation was of very low safety significance and was entered into the licensees CAP as AR 1378695, this violation is being treated as an NCV Violation, consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000282/2013007-02; 05000306/2013007-02, Failure to Review the Suitability of the CL Strainers Under Post-Seismic Flow Conditions).
1R21 Component Design Bases Inspection
.1 Introduction
The objective of the Component Design Bases Inspection is to verify the design bases have been correctly implemented for the selected risk-significant components and the operating procedures, and operator actions are consistent with design and licensing bases. As plants age, their design bases may be difficult to determine and an important design feature may be altered or disabled during a modification. The Probabilistic Risk-Assessment (PRA) 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.
Specific documents reviewed during the inspection are listed in the Attachment to the report.
.2 Inspection Sample Selection Process
The inspectors used information contained in the licensees PRA and the Prairie Island Nuclear Generating Plants Standardized Plant Analysis Risk (SPAR) model to identify two scenarios to use as the basis for component selection. The scenarios selected were loss of cooling water and steam generator tube rupture (SGTR) events. Based on these scenarios, a number of risk-significant components were selected for the inspection.
The inspectors also used additional component information such as a margin assessment in the selection process. This design margin assessment considered original design reductions caused by design modifications, power uprates, or reductions due to degraded material condition. Equipment reliability issues were also considered in the selection of components for detailed review. These included items such as performance test results, significant corrective actions, repeated maintenance activities, Maintenance Rule (a)(1) status, components requiring an operability evaluation, NRC resident inspector input of problem areas/equipment, and system health reports.
Consideration was also given to the uniqueness and complexity of the design, operating experience, and the available defense in depth margins. A summary of the reviews performed and the specific inspection findings identified are included in the following sections of the report.
The inspectors also identified procedures and modifications associated with the selected components. In addition, the inspectors selected operating experience issues associated with the selected components.
This inspection constituted 24 samples (16 components and 8 operating experience) as defined in IP 71111.21-05.
.3 Component Design
a. Inspection Scope
The inspectors reviewed the USAR, Improved Technical Specifications (ITS) design basis documents (DBDs), drawings, calculations, and other available design basis information, to determine the performance requirements of the selected components.
The inspectors used applicable industry standards, such as the ASME Code, Institute of Electrical and Electronics Engineers (IEEE) Standards and the National Electric Code, to evaluate acceptability of the systems design. The inspectors also evaluated licensee actions, if any, taken in response to NRC issued operating experience, such as Bulletins, Generic Letters (GLs), Regulatory Issue Summaries (RISs), and Information Notices (INs). The review was to verify the selected components would function as designed when required and support proper operation of the associated systems. The attributes needed for a component to perform its required function include process medium, energy sources, control systems, operator actions, and heat removal. The attributes to verify the component condition and tested capability was consistent with the design bases and was appropriate may include installed configuration, system operation, detailed design, system testing, equipment and environmental qualification, equipment protection, component inputs and outputs, operating experience, and component degradation.
For each of the components selected, the inspectors reviewed the maintenance history, preventative maintenance activities, system health reports, operating experience-related information, vendor manuals, electrical and mechanical drawings, and licensees CAP documents. Field walkdowns were conducted for all accessible components to assess material condition and to verify the as-built condition was consistent with the design.
Other attributes reviewed are included as part of the scope for each individual component.
The following 16 components (inspection samples) were reviewed:
- 125 Volts direct current (Vdc) Distribution Panels 11 and 17: The inspectors reviewed various electrical calculations, including load flow calculations to determine whether the panels were applied within their required current ratings; voltage drop calculations to determine whether loads had their required minimum voltage and whether they were applied within their maximum voltage rating during battery equalizing; and short circuit and protective device calculations to determine whether equipment was adequately protected and immune from spurious tripping. The inspectors also reviewed maintenance schedules, procedures, and maintenance records, including circuit breaker test requirements, to determine whether the panels and their associated circuit breakers were being properly maintained. In addition, the inspectors performed a visual inspection of the 125 Vdc Distribution Panels to assess material condition and the presence of hazards.
- 4160 Volts alternating current (Vac) Bus 15: The inspectors reviewed load flow calculations, short circuit calculations, and incoming breakers protective relay trip setpoints to evaluate the adequacy of the switchgear bus and breakers to carry anticipated loads under limiting condition and to withstand and interrupt maximum available faults. The review included electrical protection settings versus equipment ratings, prevention of spurious tripping, upstream-downstream coordination, and capability of protective devices to guard against low magnitude faults. The inspectors reviewed the voltage profile of the offsite system, voltage drop calculations, and the setting of degraded and loss of voltage relays and associated timers to confirm adequate voltage was available at the terminals of the safety-related loads, such as motor operated valves (MOVs), under worst operating and accident conditions. The inspectors reviewed control logics and wiring diagrams of the supply breakers to confirm automatic transfers between the normal and alternate sources as described in the USAR and in accordance with operating procedures. The review also verified adequate voltage was available to the control circuits for the proper closing and tripping of circuit breakers, the automatic transfer of loads from the preferred to the alternate offsite source (cooling tower bus) could be accomplished under postulated conditions and actuation of the degraded and loss of voltage relays initiated emergency diesel generator starting sequence. The control of bus tie-breakers was also reviewed to assure paralleling of redundant sources was not allowed. The inspectors reviewed maintenance schedules and testing procedures for the 4160 Vac bus and its associated circuit breakers to verify the equipment was being properly maintained and that testing procedures were consistent with industry standards and vendor recommendations. The review included the system health report, the results of recent maintenance and test activities, and resolution of selected condition reports to ensure the switchgear bus and breakers were maintained in acceptable operating conditions. In addition, the inspectors performed a visual inspection of the 4160 Vac safety buses to assess material condition and to verify equipment alignment, nameplate data, and breaker positions were consistent with design drawings.
- 4160 Vac Bus 27: The inspectors reviewed the capability of the bus to provide quality power to the 121 Cooling Water Pump. The inspectors reviewed bus loading calculations to confirm the bus had sufficient capacity to support its required loads under worst case accident loading and grid voltage conditions. The inspectors also reviewed voltage drop calculations to verify adequate voltage was available to the bus and pump motor. The review evaluated the switchgear design, the relay protection provided, the circuit breaker interrupting capability, and the ability of the bus to withstand available symmetrical and asymmetrical short circuit currents. The review included protective relay coordination curves to assure the pump motor was adequately protected and selective breaker tripping with upstream breakers was provided under overload and faulted conditions. The inspectors reviewed manual interlocks and control logic and wiring diagrams to confirm operation of the supply breakers was consistent with operating procedures and the USAR description. The inspectors also reviewed the 125 Vdc system voltage drop calculations to confirm that the circuit breakers had adequate control voltage under limiting operating conditions. The inspectors reviewed circuit breaker maintenance schedules and procedures to determine whether the equipment was being properly maintained.
The review included corrective action documents and maintenance records to confirm the capability of the breaker to operate on demand. The inspectors performed a visual inspection of the switchgear equipment to assess material condition and to verify equipment alignment and breaker position were consistent with design drawings.
- 480 Vac Motor Control Center (MCC) 1AB2: The inspectors reviewed the design and operation of the motor control center to verify it was capable of performing its design basis function. The review verified the bus loading was within the design rating of the equipment and the equipment rating exceeded the maximum calculated short circuit currents. The inspectors also reviewed protective coordination studies to confirm selective coordination existed between supply circuit breakers and load protective devices, including thermal overloads, and to ensure the equipment was adequately protected and faulted conditions were isolated without unnecessary loss of equipment. The inspectors reviewed voltage drop calculations to confirm adequate voltage was available to the MCC loads and motor starters and to assure safety-related loads were available on demand. The inspectors interviewed the system engineers and reviewed the system health report and maintenance activities to verify the bus components were adequately maintained. The review included maintenance and testing of molded case circuit breakers, motor starters, and thermal overloads to confirm testing activities conformed to manufacturer recommendations.
Finally, the inspectors conducted field walkdowns to assess the material condition of the MCC and to verify equipment alignment, nameplate data, and breaker positions were consistent with design drawings.
- 480 Vac MCC 1K1: The inspectors reviewed the design and operation of the motor control center to verify it was capable of performing its design basis function. The review verified the bus loading was within the design rating of the equipment and the equipment rating exceeded the maximum calculated short circuit faults. The inspectors also reviewed protective coordination studies to confirm selective coordination existed between supply circuit breakers and load protective devices, including thermal overloads, and to ensure the equipment was adequately protected and faulted conditions were isolated without unnecessary loss of equipment. The inspectors reviewed voltage drop calculations to confirm adequate voltage was available to the MCC loads and motor starters and to assure safety-related loads were available on demand. The inspectors interviewed the system engineers and reviewed the system health report and maintenance activities to verify the bus components were adequately maintained. The review included maintenance and testing of molded case circuit breakers, motor starters, and thermal overloads to confirm testing activities conformed to manufacturer recommendations. Finally, the inspectors conducted field walkdowns to assess the material condition of the MCC and to verify equipment alignment, nameplate data, and breaker positions were consistent with design drawings.
- 480 Vac MCC 1K2: The inspectors reviewed the design and operation of the motor control center to verify it was capable of performing its design basis function. The review verified the bus loading was within the design rating of the equipment and the equipment rating exceeded the maximum calculated short circuit faults. The inspectors also reviewed protective coordination studies to confirm that selective coordination existed between supply circuit breakers and load protective devices, including thermal overloads, and to ensure the equipment was adequately protected and faulted conditions were isolated without unnecessary loss of equipment. The inspectors reviewed voltage drop calculations to confirm adequate voltage was available to the MCC loads and motor starters and to assure safety-related loads were available on demand. The inspectors interviewed the system engineers and reviewed the system health report and maintenance activities to verify the bus components were adequately maintained. The review included maintenance and testing of molded case circuit breakers, motor starters, and thermal overloads to confirm testing activities conformed to manufacturer recommendations. Finally, the inspectors conducted field walkdowns to assess the material condition of the MCC and to verify equipment alignment, nameplate data, and breaker positions were consistent with design drawings.
- Motor Driven Cooling Water (CL) Pump 121: The inspectors reviewed the system hydraulic calculations such as net positive suction head (NPSH) and minimum required flow to ensure the pumps were capable of providing their function and design basis were consistent with the instructions provided by applicable procedures.
In addition, the inspectors reviewed completed surveillance tests to confirm the acceptance criteria and test results demonstrated the capability of the pump to provide required flow rates. In-service test (IST) results were reviewed to assess potential component degradation and impact on design margins. Design change history, corrective actions, surveillance results, and trending data were reviewed to assess potential component degradation and impact on design margins. The inspectors performed visual non-intrusive inspections to assess the installation configuration, material condition, and potential vulnerability to hazards. The inspectors reviewed the system design basis associated with the capability of recovering from a postulated single failure. The inspectors reviewed degraded grid voltage calculation results to determine voltage available at motor terminals and confirm the capability of the pump to perform its intended safety function under most limiting design conditions. The inspectors also reviewed motor/pump performance curves to confirm the electrical load was correctly included in the load flow and voltage analysis. The inspectors reviewed motor feeder ampacity, short circuit capability, and protective relays setting to assess the adequacy of the circuit protection under normal and faulted conditions and ensure trip setpoints would not allow the feeder breaker to trip during pump motor highest loading conditions.
Additionally, the inspectors reviewed breaker interlocks provided and control schematics to verify compliance with system operation requirements. The review also included recent electrical maintenance and test activities to confirm the readiness of the component to perform its required functions during system demands.
- Diesel Driven Cooling Water Pump 12: The inspectors reviewed the system hydraulic calculations such as NPSH and minimum required flow to ensure the pumps were capable of providing their function and design basis were consistent with the instructions provided by applicable procedures. In addition, the inspectors reviewed completed surveillance tests to confirm the acceptance criteria and test results demonstrated the capability of the pump to provide required flow rates. The IST results were reviewed to assess potential component degradation and impact on design margins. The inspectors also reviewed diesel fuel oil consumption and storage to assess the availability of the required fuel oil volume. The inspectors reviewed underground fuel oil tank buoyancy and structural calculations, and procedures to assess tank protection against external events such as flooding. The fuel oil monitoring limits were reviewed to assess fuel oil quality. The inspectors also reviewed room heat-up, jacket water, and lube oil cooling calculations to assess diesel engine cooling capacity. Also, the inspectors reviewed calculations and surveillances associated with starting air to assess starting capacity. Design change history, corrective actions, surveillance results, and trending data were reviewed to assess potential component degradation and impact on design margins. The inspectors performed visual non-intrusive inspections to assess the installation configuration, material condition, and potential vulnerability to hazards
- Cooling Water Strainer 12: The inspectors reviewed system hydraulic calculations such as minimum required flow rates under different postulated scenarios to ensure the effects of the strainer were appropriately considered. In addition, hydraulic calculations for maximum expected flow rates were reviewed to ensure operating conditions were consistent with the strainer design. The inspectors also reviewed calculations, test procedures, and recent test results for the safety-related backup air supply to the backwash mechanism. Corrective actions were reviewed to assess potential component degradation and impact on design margins. The inspectors performed visual non-intrusive inspections to assess the installation configuration, material condition, and potential vulnerability to hazards. The inspectors also reviewed voltage drop calculation results to determine voltage available at motor terminals and at the motor starter coil and to confirm the capability of the strainer to perform its intended safety function under most limiting design conditions. The inspectors reviewed motor feeder ampacity and protective coordination studies to assess the adequacy of the circuit protective devices under normal and faulted conditions and ensure the circuit breaker trip setpoints and thermal overload settings would not allow the circuit to open during strainer motor highest loading conditions.
Additionally, the inspectors reviewed control schematics to verify the component compliance with system operation requirements.
- Residual Heat Removal (RHR) Heat Exchanger 11: The inspectors reviewed calculations that determined the flow requirements for the heat exchanger and maximum number of tube circuits that can be plugged while maintaining the ability to remove the design basis cooling load. Design change history, corrective actions, surveillance results, and trending data were reviewed to assess potential component degradation and impact on design margins.
- 12 Component Cooling Heat Exchanger Cooling Water Inlet Motor Operated Valve MV-32146: The inspectors reviewed calculations such as required thrust to ensure the valve was capable of functioning under design conditions. Recent IST results were reviewed to verify acceptance criteria were met and performance degradation would be identified. Design change history, corrective actions, surveillance results, and trending data were reviewed to assess potential component degradation, impact on design margin. The inspectors performed visual non-intrusive inspections to assess the installation configuration, material condition, and potential vulnerability to hazards. The inspectors verified the control circuit testing and calibration was comprehensive. The inspectors also reviewed MOV test procedures and recent results to verify the actual capability of the installed equipment. The inspectors conducted interviews with the responsible system engineer and MOV engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors also reviewed the capability of the electrical system to support valve operation. The inspectors reviewed load flow and voltage drop calculations to evaluate the capability of the source of electrical power to supply adequate voltage to the valve motor under worst degraded grid voltage conditions. The control voltage drop calculations and control fuse sizing were also reviewed to confirm the availability of the circuit on demand. The inspectors reviewed control logic diagrams to verify controls and interlocks were consistent with the design-basis performance requirements and operating procedures. The inspectors also reviewed breaker sizing, circuit protection/coordination, and thermal overload sizing and application to confirm the circuit was adequately protected under faulted conditions and ensure its availability under limiting loading conditions. The inspectors also evaluated maintenance requirements and test procedures, as well as recent maintenance and test activities to confirm availability of the component on demand.
- Turbine Driven (TD) Auxiliary Feed Water (AFW) Pump 11: The inspectors reviewed design analyses associated with the AFW pump capacity, NPSH, run out flow protection, minimum flow protection, failure of a Condensate Storage Tank (CST),and the pump suction supply transfer. The inspectors also reviewed analyses associated with the setpoints of the AFW pump suction and discharge pressure trips.
The inspectors reviewed pump performance test procedures and recent test results to verify the actual capability of the installed equipment. The inspectors reviewed normal, abnormal, and emergency operating procedures associated with operation of the AFW pump. The inspectors reviewed potential flooding of the AFW pump room to verify the availability of the required equipment. The inspectors performed walkdowns of the pump, pump suction piping, and associated equipment, conducted interviews with the responsible system engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors also observed the use of the pump during simulator exercises involving a SGTR event and involving the transfer of the pump suction supply from the CST to the CL system. The inspectors reviewed control schematics to verify the system operation complied with the system design requirements.
- 11 TD AFW Pump Main Steam Supply Control Valve CV-31998: The inspectors reviewed design analyses associated with the air-operated control valve to verify its operation under all normal, transient, and accident conditions. The inspectors reviewed test procedures and recent test results to verify the actual capability of the installed equipment. The inspectors also reviewed the capacity of the air accumulator associated with the valve, as well as the leakage testing associated with the accumulator, to verify the capability of the valve to close when required. The inspectors performed walkdowns of the valve, air accumulator, and associated equipment, conducted interviews with the responsible system engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors reviewed control logic diagrams to verify controls and interlocks were consistent with the design-basis performance requirements and operating procedures. Additionally, the inspectors reviewed adequacy of control power available and instrumentation provided to confirm the valve received correct control signals and was capable of operating in accordance with design.
- 11 Steam Generator Main Steam Supply to 11 TD AFW Pump MOV MV32016:
The inspectors reviewed design analysis associated with the motor-operated valve to verify its operation under all normal, transient, and accident conditions. The inspectors reviewed test procedures and recent test results to verify the actual capability of the installed equipment. The inspectors reviewed emergency operating procedures associated with operation of the valve during SGTR events. The inspectors performed walkdowns of the valve and associated equipment, conducted interviews with the responsible system engineer and MOV engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors also observed the manual operation of the valve during a simulator exercise involving a SGTR event. The inspectors reviewed the capability of the electrical system to support valve operation. The inspectors reviewed load flow and voltage drop calculations to evaluate the capability of the source of electrical power to supply adequate voltage to the valve motor under worst degraded grid voltage conditions. The control voltage drop calculations and control fuse sizing were also reviewed to confirm the availability of the circuit on demand. The inspectors reviewed control logic diagrams to verify controls and interlocks were consistent with the design-basis performance requirements and operating procedures. The inspectors also reviewed breaker sizing, circuit protection/coordination, and thermal overload sizing and application to confirm that the circuit was adequately protected under faulted conditions and ensure its availability under limiting loading conditions. The inspectors also evaluated maintenance requirements and test procedures as well as recent maintenance and test activities to confirm availability of the component on demand.
- 11 RHR Heat Exchanger to 11 Safety Injection (SI) Pump Suction Isolation MOV MV-32206: The inspectors reviewed design analysis associated with the motor-operated valve to verify its operation under all normal, transient, and accident conditions. The inspectors reviewed test procedures and recent test results to verify the actual capability of the installed equipment. In addition, the inspectors reviewed the design and testing of valve interlocks provided to prevent the inadvertent opening of the valve under accident conditions. The inspectors reviewed emergency operating procedures associated with operation of the valve during LOCA events.
The inspectors performed walkdowns of the valve and associated equipment, conducted interviews with the responsible system engineer and MOV engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors reviewed the capability of the electrical system to support valve operation. The inspectors reviewed load flow and voltage drop calculations to evaluate the capability of the source of electrical power to supply adequate voltage to the valve motor under worst degraded grid voltage conditions. The control voltage drop calculations and control fuse sizing were also reviewed to confirm the availability of the circuit on demand. The inspectors reviewed control logic diagrams to verify controls and interlocks were consistent with the design-basis performance requirements and operating procedures. The inspectors also reviewed breaker sizing, circuit protection/coordination, and thermal overload sizing and application to confirm the circuit was adequately protected under faulted conditions and ensure its availability under limiting loading conditions. The inspectors also evaluated maintenance requirements and test procedures as well as recent maintenance and test activities to confirm availability of the component on demand.
- SI Pump 11: The inspectors reviewed design analyses associated with the SI pump capacity, NPSH, run out flow, and minimum flow to verify the equipments capacity to perform its required functions. The inspectors also reviewed pump performance test procedures and recent results to verify the actual capability of the installed equipment. The inspectors reviewed a sample of operating procedures associated with the pump under normal and accident conditions. The inspectors performed walkdowns of the pump and associated equipment, conducted interviews with the responsible system engineer, and reviewed a sample of corrective action and maintenance documents to verify the material condition of the equipment. The inspectors also observed the use of the pump during a simulator exercise involving a SGTR event. The inspectors also reviewed the capability of the electrical system to support pump operation. The inspectors reviewed degraded grid voltage calculation results to determine voltage available at motor terminals and confirm the capability of the pump to perform its intended safety function under most limiting design conditions. The inspectors also reviewed motor/pump performance curves to confirm the electrical load was correctly included in the load flow and voltage analysis. The inspectors reviewed motor feeder ampacity, short circuit capability, and protective relays setting to assess the adequacy of the circuit protection under normal and faulted conditions and ensure trip setpoints would not allow the feeder breaker to trip during pump motor highest loading conditions. Additionally, the inspectors reviewed control logic and wiring schematics to verify compliance with system operation requirements. The review also included recent electrical maintenance and test activities to confirm the readiness of the component to perform its required function during system demands.
b. Findings
- (1) Failure to Demonstrate the Ability to Transfer Diesel Fuel Oil Between Unit 1 Fuel Oil Tanks
Introduction:
A finding of very low safety significance and associated NCV Violation of 10 CFR Part 50, Appendix B, Criterion XI, Test Control, was identified by the inspectors for the failure to demonstrate the ability to transfer diesel fuel oil from any Unit 1 fuel oil storage tank to any Unit 1 emergency diesel generator (EDG) or diesel driven CL pump day tank.
Description:
The inspectors noted the licensee was not periodically testing the transfer capability of diesel fuel between any Unit 1 fuel oil storage tank and any day tank associated with the Unit 1 EDGs and diesel driven CL pumps. This transfer capability was credited by the licensing basis of the plant. Specifically, Section 3.7.8 of Technical Specifications (TS) Basis, Cooling Water System, stated There are four Design Class I fuel oil storage tanks for the Unit 1 EDGs and two Design Class I fuel oil storage tanks for the diesel driven cooling water pumps. It further stated These six tanks are interconnected such that any tank can be manually aligned to supply any Unit 1 EDG or diesel driven cooling water pump day tank. In addition, it stated Any combination of inventory in these six tanks may be used to satisfy the inventory requirements for the diesel driven cooling water pumps and the Unit 1 EDGs. The inspectors noted Section 10.3.13 of the USAR, Fuel Oil System, also contained similar statements. In addition, a review of the associated calculations and surveillance procedures confirmed the minimum fuel oil volume required by TS 3.7.8 and TS 3.8.3, for Unit 1 could only be physically met by crediting the ability to interconnect the tanks.
The licensee captured the inspectors concerns with respect to the transfer capability in their CAP as AR 1377734. The corrective action considered at the time of this inspection was to create an action to periodically verify the transfer capability. In addition, the licensee determined the affected flow paths were used in 2010 and 2011 during tank fuel recirculation activities which provided reasonable assurance the flow paths were available.
Analysis:
The inspectors determined the failure to demonstrate the ability to transfer diesel fuel oil from any Unit 1 fuel oil storage tank to any Unit 1 EDG or diesel driven CL pump day tank was contrary to 10 CFR Part 50, Appendix B, Criterion XI, Test Control, and was a performance deficiency. The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of equipment performance and affected the cornerstone objective of ensuring the availability, reliability, and capability of the Unit 1 EDGs and diesel drivel CL pumps to respond to initiating events to prevent undesirable consequences. Specifically, the failure to verify the fuel oil transfer capability did not ensure the minimum fuel oil volume required by TS could be supplied to these systems to support their accident mitigating function.
The inspectors determined the finding could be evaluated using the Significance Determination Process, Attachment 0609.04, Initial Characterization of Findings.
Because the finding affected the Mitigating Systems cornerstone, the inspectors screened the finding through IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power, using Exhibit 2, Mitigating Systems Screening Questions. The finding screened as of very low safety significance (Green) because it did not result in the loss of operability or functionality. Specifically, the licensee determined the affected flow paths were used in 2010 and 2011 during tank fuel recirculation activities which provided reasonable assurance the flow paths were available.
The inspectors did not find an applicable cross-cutting aspect which represented the underlying cause of this performance deficiency; therefore, no cross-cutting aspect was assigned.
Enforcement:
Title 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires, in part, that a test program shall be established to assure all testing required to demonstrate structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptable limits contained in applicable design documents.
Contrary to the above, as of April 19, 2013, the licensee failed to conduct tests that demonstrated the capability to transfer diesel fuel oil from any Unit 1 fuel oil storage tank to any Unit 1 EDG and diesel driven CL pump day tank as credited by USAR and TS.
The inspectors determined the continued non-compliance did not present an immediate safety concern because licensee reasonably demonstrated the affected flow paths were available. Because this violation was of very low safety significance and was entered into the licensees CAP as AR 1377734, this violation is being treated as an NCV Violation, consistent with Section 2.3.2 of the NRC Enforcement Policy.
(NCV 05000282/2013007-03; 05000306/2013007-03, Failure to Demonstrate the Ability to Transfer Diesel Fuel Oil Between Unit 1 Fuel Oil Tanks).
.4 Operating Experience
a. Inspection Scope
The inspectors reviewed eight operating experience issues (inspection samples) to ensure NRC generic concerns were adequately evaluated and addressed by the licensee. The issues listed below were reviewed as part of this inspection:
- GL 95-07, Pressure locking and thermal binding of safety-related power-operated gate valves;
- IN 2012-03, Design vulnerability in Electrical distribution System (Single phasing);
- IN 2010-26, Cable submergence;
- IN 92-05, Part 21 on coil RXMH2 Relay;
- CAP 01285449, NRC Bulletin 2011-01, Mitigating Strategies; and
- IN 2004-01, Auxiliary Feed Water Pump Recirculation Line Orifice Fouling - Potential Common Cause Failure.
b. Findings
No findings were identified.
.5 Plant Modifications
a. Inspection Scope
The inspectors reviewed two permanent plant modifications related to selected risk significant components to verify the design bases, licensing bases, and performance capability of the components had not been degraded through modifications. The modifications listed below were reviewed as part of this inspection effort:
- Engineering Change Notice (ECN) 17202, Replacement of Unit 1 Safety-Related Battery Chargers(No. 11 and No. 12); and
- ECN 18365, RHR-SI Pressure Locking.
b. Findings
No findings were identified.
.6 Operating Procedure Accident Scenario Reviews
a. Inspection Scope
The inspectors performed detailed review of risk significant, time critical operator actions. These actions were selected from the licensees PRA rankings of human action importance based on risk achievement worth values and selected scenarios of loss of cooling water and SGTR. For the selected operator actions, the inspectors reviewed licensee procedures; and training provided to operators and performed plant walkdowns.
The inspectors observed the licensee-developed simulator scenarios to determine whether operators were implementing the procedure steps in a timely manner and to verify the procedures were appropriate to sufficiently mitigate the events.
The procedures were compared to USAR and risk assumptions. In addition, the procedures were reviewed to ensure the procedure steps would accomplish the desired result. The following operator actions were reviewed:
- Operator fails to cool down and depressurize reactor coolant system for SGTR;
- Scenario: SGTR with Loss of Bus 16; and
- Scenario: Loss of Offsite Power, Reactor Trip and Loss of CST and swap of AFW suction to CL.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA2 Identification and Resolution of Problems
.1 Review of Items Entered Into the Corrective Action Program (CAP)
a. Inspection Scope
The inspectors reviewed a sample of the selected component problems that were identified by the licensee and entered into the CAP. The inspectors reviewed these issues to verify an appropriate threshold for identifying issues and to evaluate the effectiveness of corrective actions related to design issues. In addition, corrective action documents written on issues identified during the inspection were reviewed to verify adequate problem identification and incorporation of the problem into the CAP. The specific corrective action documents that were sampled and reviewed by the inspectors are listed in the Attachment to this report.
b. Findings
No findings were identified.
4OA6 Management Meetings
.1
Exit Meeting Summary
On April 19, 2013, the inspectors conducted a final exit of the inspection results with Mr. Jim Lynch, and other members of the licensee staff. The licensee acknowledged the issues presented. The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. Several documents reviewed by the inspectors were considered proprietary information and were either returned to the licensee or handled in accordance with NRC policy on proprietary information.
ATTACHMENT:
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee
- J. Lynch, Site Vice President
- J. Anderson, Regulatory Affairs Manager
- T. Bacon, Assistant Operations Manager
- N. Bibus, Control Room Supervisor
- T. Borgen, Training Manager
- J. Connors, Fleet Design Engineering Supervisor
- K. Davison, Site Operations Director
- L. Farrell, Programs Engineering
- K. Herder, Programs Engineering
- S. Kerins, Procurement Engineering
- S. Lappegard, Production Manager
- J. Lash, Nuclear Oversight Manager
- J. Loeffler, Design Engineering
- J. Mathew, Design Engineering Manager
- A. Mitchell, Engineering Director
- P. Oleson, Regulatory Affairs
- S. Schmidt, Shift Manager
- S. Sharp, Plant Manager
- J. Windschill, Performance Assessment Manager
- P. Zamarripa, Design Engineering
Nuclear Regulatory Commission
- G. Shear, Director, Division of Reactor Safety
- A. Stone, Chief, Engineering Branch 2
- K. Stoedter, Senior Resident Inspector
LIST OF ITEMS
OPENED, CLOSED AND DISCUSSED
Opened and Closed
- 05000306/2013007-01 NCV Failure to Verify the Adequacy of Cooling Water System Design. (Section 1R07.1.b(1))
- 05000306/2013007-02 NCV Failure to Review the Suitability of the CL Strainers Under Post-seismic Flow Conditions.
(Section 1R07.1.b(2))
- 05000306/2013007-03 NCV Failure to Demonstrate the Ability to Transfer Diesel Fuel Oil Between Unit 1 Fuel Oil Tanks.
(Section 1R21.3.b(1))