IR 05000269/2011002
| ML111330365 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/13/2011 |
| From: | Bartley J NRC/RGN-II/DRP/RPB1 |
| To: | Gillespie T Duke Energy Carolinas |
| References | |
| IR-11-002 | |
| Download: ML111330365 (36) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION May 13, 2011
SUBJECT:
OCONEE NUCLEAR STATION - NRC INTEGRATED INSPECTION REPORT 05000269/2011002, 05000270/2011002, 05000287/2011002
Dear Mr. Gillespie:
On March 31, 2011, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Oconee Nuclear Station Units 1, 2, and 3. The enclosed inspection report documents the inspection results, which were discussed on April 18, 2011, with you and other members of your staff.
The inspection examined activities conducted under your licenses as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your licenses. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.
This report documents an NRC-identified finding for the licensees failure to ensure that a modification to the Standby Shutdown Facility (SSF) diesel generator monitoring panel would not affect the ability of the SSF Power subsystem to perform its design function. The safety significance of this finding is potentially greater than very low safety significance. The finding does not represent an immediate safety concern because the chart recorder was modified so that it did not affect the SSF Power subsystem.
In addition, this report documents one NRC-identified finding of very low safety significance which was determined to be a violation of NRC requirements. Additionally, a licensee-identified violation, which was determined to be of very low safety significance, is listed in this report.
However, because of the very low safety significance and because they are entered into your corrective action program, the NRC is treating these violations as non-cited violations (NCVs)
consistent with Section 2.3.2 of the NRC Enforcement Policy. If you contest 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 20555-001; with copies to the Regional Administrator Region II; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspector at Oconee. In addition, if you disagree with the characterization of any finding in this report, you should provide a response within 30 days of
DEC 2 the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region II, and the NRC Resident Inspector at Oconee.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Jonathan H. Bartley, Chief Reactor Projects Branch 1 Division of Reactor Projects Docket Nos.: 50-269, 50-270, 50-287, 72-04 License Nos.: DPR-38, DPR-47, DPR-55
Enclosure:
NRC Integrated Inspection Report 05000269/2011002, 05000270/2011002, 05000287/2011002w/Attachment: Supplemental Information
REGION II==
Docket Nos: 50-269, 50-270, 50-287, 72-40 License Nos: DPR-38, DPR-47, DPR-55 Report Nos: 05000269/2011002, 05000270/2011002, 05000287/2011002 Licensee: Duke Energy Carolinas, LLC Facility: Oconee Nuclear Station, Units 1, 2 and 3 Location: Seneca, SC 29672 Dates: January 1, 2011, through March 31, 2011 Inspectors: A. Sabisch, Senior Resident Inspector G. Ottenberg, Resident Inspector K. Ellis, Resident Inspector J. Hamman, Resident Inspector G. Crespo, Senior Construction Inspector (Section 1R17)
P. Higgins, Senior Reactor Inspector (Section 1R17)
G. Johnson, Operations Engineer (Section 1R11)
E. Lea, Senior Operations Engineer (Section 1R11)
Approved by: Jonathan H. Bartley, Chief Reactor Projects Branch 1 Division of Reactor Projects Enclosure
SUMMARY OF FINDINGS
IR 05000269/2011-002, 05000270/2011-002, 05000287/2011-002; 01/01/2011 - 03/31/2011;
Oconee Nuclear Station Units 1, 2 and 3; Maintenance Risk Assessment and Emergent Work Control, Plant Modifications The report covered a three-month period of inspection by the resident inspectors and four region-based inspectors. This report documents one apparent violation (AV) which was potentially greater than
- Green.
In addition, one non-cited violation (NCV) was identified. The significance of most findings is indicated by their color (Green, White, Yellow, Red) using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP). Cross-cutting aspects are determined using IMC 0310, Components Within The Cross-Cutting Areas.
Findings for which the SDP does not apply may be Green or be assigned a severity level after NRC management review. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process.
Cornerstone: Mitigating Systems
- Green.
An NRC-identified non-cited violation of 10 CFR 50.65(a)(4) was identified for the licensees failure to effectively implement risk mitigation actions as defined in the Complex Activity Plan for the Unit 2 Cask Decon Tank Room and West Penetration Room (WPR)
Siding Demolition project. A temporary seismic barrier was not properly constructed and would not have protected safety-related equipment in the event of a WPR wall collapse. The licensee delayed removal of the girts until the construction deficiencies were corrected. This condition was placed into the corrective action program (CAP) as Problem Investigation Program report (PIP) O-11-00747.
The failure to implement a risk mitigation action in accordance with the Complex Activity Plan was a performance deficiency (PD). The PD was more than minor because it had the potential to become a more significant safety concern if left uncorrected in that the temporary seismic barrier would not have performed its intended function of protecting safety-related equipment if the WPR wall collapsed. The finding was of very low safety significance (Green) because there was no increase in the Incremental Core Damage Probability since the construction deficiencies were corrected prior to removal of the girts.
The cause of the finding was directly related to the Supervisory and Management Oversight aspect of the Work Practices component in the cross-cutting area of Human Performance because the licensee failed to ensure that the appropriate level of supervisory and management oversight was applied to the installation of the temporary seismic barrier.
H.4(c) (Section 1R13)
- TBD. An NRC-identified Apparent Violation of 10 CFR 50, Appendix B, Criterion III, Design Control, was identified for the licensees failure to ensure that a modification installed on the Safe Shutdown Facility (SSF) Diesel Generator (DG) monitoring panel would not affect the ability of the SSF Power subsystem to perform its design function. The finding does not represent an immediate safety concern because the chart recorder was modified so that it did not send an output signal to the SSF control and protection logic circuit.
The licensees failure to ensure the post-modification testing was adequate to verify the modification did not affect the SSF Power subsystems ability to perform its design function was a performance deficiency (PD). The PD was determined to be more than minor because it was associated with the Mitigating Systems Cornerstone attribute of Equipment Performance and adversely impacted the cornerstone objective in that the modification would have prevented the SSF DG from starting and supplying power to the SSF. The safety significance of this finding was To Be Determined pending completion of a Phase III risk analysis. The finding was directly related to the cross-cutting area of Human Performance under the Procedural Compliance aspect of the Work Practices component because the licensee failed to ensure station modification program requirements were followed in the development of post-modification testing. H.4(b) (Section 1R18)
REPORT DETAILS
Summary of Plant Status
Unit 1 began the inspection period at approximately 100 percent rated thermal power (RTP).
On January 8, 2011, the unit entered Mode 5 to repair a containment isolation valve. The unit was returned to 100 percent RTP on January 17, 2011, where it remained for the rest of the inspection period.
Unit 2 began the inspection period at approximately 100 percent RTP where it remained for the duration of the inspection period.
Unit 3 began the inspection period at approximately 100 percent RTP until January 21, 2011, when a secondary side steam leak required a downpower to approximately 16 percent RTP for repairs. The unit was returned to 100 percent RTP on January 23, 2011, where it remained for the rest of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity
1R01 Adverse Weather Protection
a. Inspection Scope
Actual Adverse Weather Conditions: The inspectors assessed the licensees response to the following adverse weather condition. Documents reviewed are listed in the
.
- On January 10 - 11, 2011, the site area experienced a severe winter storm producing extreme cold weather along with snow and ice accumulation. The inspectors reviewed selected areas to ensure adequate measures were in place to ensure the safety-related and risk significant components were protected and verified that actions called for in the operators cold weather checklist and adverse weather preparation procedures had been performed during this period. Inspectors reviewed actual staffing levels, the licensees assessment of Part 26 requirements and contingency measures established to ensure minimum required staffing levels were maintained.
External Flooding: The inspectors conducted a walkdown of the exterior walls of the Auxiliary Building including the Cask Decon Tank Rooms, and the below grade floors following a period of rain onsite to ensure adequate measures or design features were in place to prevent water from entering the building and impacting plant equipment. The walkdown also included the outside yard drains to ensure they were clear of debris and functional. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R04 Equipment Alignment
a. Inspection Scope
Partial Walkdown: The inspectors performed the four partial walkdowns listed below to assess the operability of redundant or diverse trains and components when safety-related equipment was inoperable or out-of-service and to identify any discrepancies that could impact the function of the system potentially increasing overall risk. The inspectors reviewed applicable operating procedures and walked down system components, selected breakers, valves, and support equipment to determine if they were correctly aligned to support system operation. The inspectors reviewed protected equipment sheets, maintenance plans, and system drawings to determine if the licensee had properly identified and resolved equipment alignment problems that could cause initiating events or impact the capability of mitigating systems or barriers and entered them into the CAP. Documents reviewed are listed in the Attachment.
- Protection of the 3B train of Low Pressure Injection (LPI) when the 3A train was removed from service for planned mechanical and electrical maintenance
- Units 1 and 2 High Pressure Injection (HPI) systems while the SSF was removed from service for planned monthly maintenance
- Protection of designated equipment in support of the repair of 0SF-49, Spent Fuel Filter Outlet Header Block Valve, which placed Units 1 and 2 in an Orange risk condition due to isolation of spent fuel pool cooling
- Protection of control switches and power supplies associated with the containment isolation valves on Unit 2 and Unit 3 providing backup for valves 2HP-5, 3HP-5, 2HP-21 and 3HP-21, which were identified as having the potential to not close when required
b. Findings
No findings were identified.
1R05 Fire Protection
a. Inspection Scope
Fire Area Tours: The inspectors walked down accessible portions of the five plant areas listed below to assess the licensees control of transient combustible material and ignition sources, fire detection and suppression capabilities, fire barriers, and any related compensatory measures. The inspectors observed the fire protection suppression and detection equipment to determine if any conditions or deficiencies existed which could impair the operability of that equipment. The inspectors selected the areas based on a review of the licensees safe shutdown analysis probabilistic risk assessment and sensitivity studies for fire-related core damage accident sequences. Documents reviewed are listed in the Attachment.
- Independent Spent Fuel Storage Installation (ISFSI)
- Turbine Building Basement, Units 1, 2, & 3
- Unit 3 Main Control Room
- Unit 3 LPI and Reactor Building Spray pump rooms
- Keowee Hydro Station Fire Drill Observation: On March 18, 2011, the licensee conducted a shift fire drill simulating a fire in the Unit 1 Equipment Room. The inspectors observed this drill to verify the fire brigades use of protective gear and fire-fighting equipment; that fire fighting pre-plan procedures and appropriate fire fighting techniques were used; and that the directions of the fire brigade leader were thorough, clear, and effective. The inspectors also observed the post-drill critique to assess if it was appropriately critical, included discussions of drill observations, and identified any areas requiring corrective action. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R06 Flood Protection Measures
a. Inspection Scope
Submerged or Buried Cable Inspection: The inspectors observed the condition of the cable trench CT-5 in the Turbine Building and sump pump operation through direct observation. The inspectors verified the trench was absent of standing water and that the cables within the trench were intact and in good condition. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R07 Heat Sink Performance
a. Inspection Scope
The inspectors observed the performance of inspection and cleaning of the Units 1B and 3B Motor Driven Emergency Feedwater (MDEFW) pump motor air coolers. The inspectors verified that the state of cleanliness of the Low Pressure Service Water (LPSW) tube side of the coolers supported allowable tube plugging assumptions. The inspectors verified the licensee was using the periodic maintenance method outlined in applicable guidance documents. The inspectors reviewed the licensees documented visual inspection checklists to verify identified conditions were accurately being reflected.
The inspectors verified proper orientation of the outlet plenum upon reinstallation to ensure the operability of the cooler. A post maintenance test was observed to verify there were no leaks following the maintenance. Documents reviewed are listed in the
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification
a. Inspection Scope
Resident Inspector Observation: The inspectors observed one active simulator exam, to assess the performance of licensed operators during a simulator training session. The scenario included a B steam generator tube rupture followed by an A main steam line break. The inspection focused on high-risk operator actions performed during implementation of the abnormal and emergency operating procedures, and the incorporation of lessons learned from previous plant and industry events. The classification and declaration of the Emergency Plan by the Operations Shift Manager was also observed during the scenario. The post-scenario critique conducted by the training instructor and the crew was observed. Documents reviewed are listed in the
.
Biennial Requalification Program Review: The inspectors reviewed documentation, interviewed licensee personnel, and observed the administration of operating tests associated with the licensees operator requalification program to assess the effectiveness of the licensee in implementing requalification requirements identified in 10 CFR Part 55, Operators Licenses. The evaluations were also performed to determine if the licensee effectively implemented operator requalification guidelines established in NUREG-1021, Operator Licensing Examination Standards for Power Reactors, and Inspection Procedure 71111.11, Licensed Operator Requalification Program. The inspectors also evaluated the licensees simulation facility for adequacy for use in operator licensing examinations using ANSI/ANS-3.5-1998, American National Standard for Nuclear Power Plant Simulators for use in Operator Training and Examination. The inspectors observed three crews during the performance of the operating tests. The inspectors also reviewed documentation including written examinations, Job Performance Measures, simulator scenarios, licensee procedures, on-shift records, simulator modification request records, simulator performance test records, operator feedback records, licensed operator qualification records, remediation plans, watchstanding records, and medical records. The records were inspected using the criteria listed in Inspection Procedure 71111.11. Documents reviewed are listed in the
.
b. Findings
No findings were identified.
1R12 Maintenance Effectiveness
a. Inspection Scope
The inspectors reviewed the licensees effectiveness in performing the following three corrective maintenance activities. These reviews included an assessment of the licensees practices pertaining to the identification, scoping, and handling of degraded equipment conditions, as well as common cause failure evaluations. For each activity selected, the inspectors performed a detailed review of the problem history and surrounding circumstances, evaluated the extent of condition reviews as required, and reviewed the generic implications of the equipment and/or work practice problem. For those structures, systems and components (SSCs) scoped in the Maintenance Rule per 10 CFR 50.65, the inspectors verified that reliability and unavailability were properly monitored and that 10 CFR 50.65 (a)(1) and (a)(2) classifications were justified in light of the reviewed degraded equipment condition. Documents reviewed are listed in the
.
- Primary Instrument Air (IA) compressor regulator disassembly and control tubing cleaning following unexpected IA header pressure decrease and entry into the station Abnormal Operating Procedure
- Troubleshooting and repair of the Unit 1 Reactor Coolant System (RCS) letdown line outboard containment isolation valve (CIV), 1HP-5
- Troubleshooting and repair of the Unit 2 Standby Bus 2 C-phase sensing circuit, specifically a slave relay, 27SY2/2C2, was mechanically bound in the energized state
b. Findings
No findings were identified.
1R13 Maintenance Risk Assessments and Emergent Work Control
a. Inspection Scope
The inspectors evaluated the following attributes for the seven activities listed below:
- (1) the effectiveness of the risk assessments performed before maintenance activities were conducted;
- (2) the management of risk;
- (3) that, upon identification of an unforeseen situation, necessary steps were taken to plan and control the resulting emergent work activities; and
- (4) that maintenance risk assessments and emergent work problems were adequately identified and resolved. Documents reviewed are listed in the
.
- Review of planned work following the Unit 1 RCS letdown line outboard CIV 1HP-5 being declared inoperable
- Review of planned and in-progress activities following declaring the SSF inoperable upon discovering the Unit 2 Pressurizer Heater Bank B supply breaker tripped
- Review of the compensatory measure for girt removal on the Unit 2 West Penetration Room wall
- Review of the planned ORANGE risk profile to modify the control power to the Keowee Underground Path breaker automatic transfer logic
- Review of planned ORANGE risk profile for Dual Keowee Hydro Unit outage
- Review of the planned ORANGE risk profile associated with the repair of 0SF-49 and required isolation of spent fuel pool cooling for the Unit 1 / Unit 2 shared spent fuel pool
- Review of the Unit 1 End-of-cycle 26 Refueling Outage Risk Profile and mitigation strategies
b. Findings
Introduction:
An NRC-identified Green NCV of 10 CFR 50.65(a)(4) was identified for the licensees failure to effectively implement risk mitigation actions as defined in the Complex Activity Plan for the Unit 2 Cask Decon Tank Room and WPR Siding Demolition project. A temporary seismic barrier was not properly constructed and would not have protected safety-related equipment in the event of a WPR wall collapse. The licensee delayed removal of the girts until the construction deficiencies were corrected.
Description:
On January 19, 2011, the licensee notified the inspectors that installation of the temporary seismic barrier on the interior side of the WPR wall was complete. This temporary seismic barrier was necessary to protect safety-related equipment after removal of the girts. The inspectors performed a walkdown of the WPR wall and noted that the temporary seismic barrier had not been constructed as specified in drawing O-155-L-009, Masonry Wall Seismic Barrier West Pen Room. The inspectors identified four separate locations with holes in the fencing large enough to allow debris to pass through and impact safety-related equipment in the event the WPR wall collapsed.
Additionally, inspectors identified several locations where the fencing had not been secured at the 24-inch spacing required by drawing O-155-L-009 and referenced in the Complex Activity Plan. The inspectors identified these deficiencies to the licensee. The licensee then delayed removal of the girts until the deficiencies were corrected. The licensees subsequent review determined that there was not proper oversight of the work to ensure the barrier met the requirements specified on the drawing.
Analysis:
The failure to implement a risk mitigation action in accordance with the Complex Activity Plan was a PD. The PD was more than minor because if left uncorrected, it had the potential to become a more significant safety concern in that the temporary seismic barrier would not have performed its intended function of protecting safety-related equipment if the WPR wall collapsed. Using IMC 0609, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process, the finding was determined to be of very low safety significance (Green)because there was no increase in the Incremental Core Damage Probability since the deficiencies were corrected prior to removal of the girts. The cause of the finding was directly related to the aspect of ensuring supervisory oversight of work activities such that nuclear safety is supported of the Work Practices component in the cross-cutting area of Human Performance because the licensee failed to ensure that the appropriate level of supervisory and management oversight was applied to the installation of the temporary seismic barrier. H.4(c)
Enforcement:
10 CFR 50.65(a)(4) required, in part, that the licensee shall assess and manage the increase in risk that may result from proposed maintenance activities.
Contrary to this requirement, from January 14 until January 19, 2011, the licensee failed to properly manage the increase in risk resulting from the planned removal of girts on the WPR wall. A temporary seismic barrier, identified as a risk mitigation action, had not been constructed according to design drawings and would not have performed its risk mitigation function. Because this finding was of very low safety significance and was entered into the licensees CAP as PIP O-11-00747, this violation is being treated as an NCV consistent with Section 2.3.2 of the NRC Enforcement Policy: NCV 05000270/2011002-01, Inadequate Risk Management Associated with the Removal of the Unit 2 West Penetration Room Girts.
1R15 Operability Evaluations
a. Inspection Scope
The inspectors reviewed the following five operability evaluations affecting risk significant systems to assess:
- (1) the technical adequacy of the evaluations;
- (2) whether continued system operability was warranted;
- (3) whether other existing degraded conditions were considered;
- (4) if compensatory measures were involved, whether the compensatory measures were in place, would work as intended, and were appropriately controlled; and
- (5) where continued operability was considered unjustified, the impact on Technical Specifications (TS) limiting condition for operation (LCO).
- Justification for declaring the Unit 1 RCS letdown line outboard CIV operable following failure to close during testing
- PIP O-11-0388, The current methodology for establishing the operational Alert setpoint per PT/0/A/0230/001 for 1(2)(3)RIA-47 does not assure that 1(2)(3)RIA-47 will detect a 1 gpm leak in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />
- PIP O-10-3882, SSF Declared Inoperable Due to OTS 1-5 86D Lockout Relay During Unit 2 J-Test and PIP O-10-4002, When Performing Electric Power Switch Logic Startup Source Voltage Sensing Circuit Testing, the SSF Diesel Generator Protective Relay Trip Actuated Unexpectedly
- PIP O-10-10789, Air Void found in Piping while performing PT/3/A/0203/012
b. Findings
No findings were identified.
1R17 Evaluations of Changes, Tests, or Experiments and Permanent Plant Modifications
a. Inspection Scope
Tornado/High Energy Line Break (HELB) Project Modification - Power Supply and Instrument Changes for the New Protected Service Water (PSW) System: The inspectors observed power and instrument cable design modifications for the new PSW system. The inspectors reviewed and examined the following four samples of permanent plant modifications:
- Instrumentation cable runs from the Unit 1, 2 and 3 control rooms to new cable termination cabinets in the Auxiliary building on El 783
- 600V power cable 1XPSW run from Manhole 7 outside the Auxiliary Building to its intended termination location inside the Auxiliary Building (approximately 1000 feet)
- The imbedded grounding configuration for manholes 3, 4, 5 and 7
- 125 VDC cable Re-Routes to tornado/HELB protected areas The inspectors examined cable trays and supports, bend radius criteria, unsupported cable length criteria, cable lubrication requirements, cable routing, separation (physical independence) and segregation (power, control, instrument) criteria, methodology used for cable pulling, methods for protection of cables from being damaged from sharp edges, hostile environments, and adjacent construction activities, and the condition of the new termination cabinets, grounding plates and grounding strap installation in manholes.
The inspectors reviewed procedures, specifications, construction documents, and corrective actions such as PIPs generated by the licensee personnel and Nonconformance Reports (NCRs) generated by the contractor related to the cable, cable tray, and cabinet installation. The inspectors reviewed or examined the licensee activities to verify that the activities met the requirements of licensee design documents, licensee procedures, licensee quality assurance plans, and industry standards. The inspectors observed to determine whether cable pulling and placement activities were continuously monitored by the licensee and contractor quality control personnel and engineers.
The inspectors noted that several cracks in the PSW building roof had been previously identified after construction of the roof. Water was observed leaking through these cracks prior to the licensee sealing the roof against moisture. The inspectors examined the PSW Building ceiling during heavy rainfall to determine if the licensee corrective action on sealing the roof was effective. No leakage or moisture was observed.
Tornado/HELB Project Modification - Power Supply Main Feeders for The New PSW System: The inspectors observed the installation of the medium voltage Fant Line main normal power feeders 5CT-3A, 3B, 3C, and 5CT-4A, 4B, 4C. The inspectors reviewed cable installation instructions, calculations, drawings, product data sheets, cable labeling procedures, implementation sequencing, and inspection and testing procedures to verify that applicable requirements were met. The inspectors discussed lessons learned by the licensee from the experience gained from the two cable pulls. The inspectors reviewed the amount and type of pulling compound used and its impact on the second feeder pull compared to the first pull.
The inspectors reviewed corrective action documentation such as PIPs associated with the problems encountered during the cable pulls. The inspectors evaluated the accuracy and thoroughness of the licensees PIP in addressing calculation discrepancies and the type and arrangement of cable pulling equipment used. The inspectors discussed licensee methods to meet maximum allowable tension and sidewall bearing pressure limits during pulling operations.
Tornado/HELB Project Modification - Inspection and Preventative Maintenance Procedures for Equipment Installed But Not Turned Over To the Plant: The inspectors reviewed procedures outlined for the preventative maintenance of equipment installed but not turned over to the plant to verify that equipment was being adequately maintained. The inspectors observed the implementation of wall mounted thermostats to monitor room temperature to ensure compliance with procedure guidelines. The inspectors discussed the schedule of equipment inspections to confirm the absence of moisture inside the equipment and to identify for any physical damage.
Tornado/HELB Project Modification - Electrical Equipment For The New PSW System:
The inspectors reviewed procurement documentation associated with the 10 megavolt-ampere (MVA), 13.8 kilovolt/4.16 kilovolt transformers designated as CT6 & CT7 to verify that requirements were met. The inspectors reviewed procurement documentation associated with the 600 Volt Motor Control Centers (MCCs) for the PSW system. The inspectors reviewed NCRs on 600 Volt MCCs, 13.8 kV Medium Voltage Switchgear and 10 MVA transformers CT6, associated with drawings, instructions, reports, specifications, procedures, test plans, acceptance testing, and component dedication plans to verify that applicable requirements were met.
b. Findings
No findings were identified.
1R18 Plant Modifications
a. Inspection Scope
The inspectors reviewed the following six plant modifications to verify the adequacy of the modification package, as well as 10 CFR 50.59 screenings, and to evaluate the modification for adverse affects on system availability, reliability and functional capability.
The Borated Water Storage Tank (BWST)/SSF Superstructure modifications were also reviewed for design and construction aspects to determine if construction activities were in accordance with design drawings. Documents reviewed are listed in the Attachment.
Permanent Plant Modifications
- EC103444, Separate SK1/SK2 logic for Unit 1, Unit 2, and Unit 3
- Replacement of SSF DG Chart Recorder with Digital Upgrade Model
- EC 97945, Unit 1 BWST/SSF Trench Protection Superstructure
- EC 97959, Unit 2 BWST/SSF Trench Protection Superstructure
- OD 500923, 100KV Fant Line Tap - security related aspects
- OD 500947, Trenching and Underground Ductbank
b. Findings
Introduction:
An NRC-identified AV of 10 CFR 50, Appendix B, Criterion III, Design Control, was identified for the licensees failure to ensure that a modification installed on the SSF DG monitoring panel would not affect the ability of the SSF Power subsystem to perform its design function. The finding does not represent an immediate safety concern because the chart recorder was modified so that it no longer affected the SSF Power subsystem.
Description:
During the fall 2008 Unit 2 refueling outage, the SSF DG main bearing temperature monitor panel was replaced with a digital chart recorder. Following installation of the chart recorder, post-modification testing only verified that the recorder accurately measured main bearing temperatures.
On May 13, 2010, the integrated loss-of-power test was performed during the Unit 2 refueling outage to verify the automatic start of the Keowee hydro units. When AC power was subsequently restored as part of the test, the chart recorder initiated a reboot sequence resulting in a false high main bearing temperature signal which sealed-in a lockout relay preventing the SSF DG from starting during a later step in the test. The licensee identified the cause of the SSF DG start failure after extensive troubleshooting and the chart recorder was modified so that it did not send an output signal to the SSF DG control and protection logic circuit.
EDM 601, Engineering Change Manual, required that post-modification testing for design changes assure the functionality of the modified SSC. The reboot sequence and generation of a false high main bearing temperature signal was discussed in the vendors technical manual and should have been included when developing appropriate post-modification testing. Consequently, the post-modification testing, performed following chart recorder installation, was inadequate because it did not verify the chart recorder reboot sequence would not affect the ability of the SSF Power subsystem to perform its design function.
The licensee initially did not evaluate the past operability of the SSF from October 2008 through May 2010. The inspectors engaged the licensee after identifying scenarios in which the reboot sequence could have rendered the SSF DG incapable of starting when called upon. The licensee acknowledged that SSF Power subsystem operability had been adversely affected and initiated a root cause to assess the condition and develop appropriate corrective actions.
Analysis:
The licensees failure to ensure the post-modification testing verified the modification did not affect the ability of the SSF Power subsystem to perform its design function was a PD. The PD was determined to be more than minor because it was associated with the Mitigating Systems Cornerstone attribute of Equipment Performance and adversely impacted the cornerstone objective in that the modification would have prevented the SSF DG from starting and providing power to the SSF. The safety significance of this finding was assessed using IMC 0609. A Phase III analysis was required because this finding represented a potential loss of function for a single train system which was not addressed by either the Phase II pre-solved tables or the plant-specific worksheets. The safety significance of this finding was preliminarily determined to be potentially greater than Green based on Senior Reactor Analyst review using an exposure time of one year. Therefore, the safety significance of this finding is To Be Determined (TBD) pending completion of a Phase III risk analysis. The PD was directly related to the cross-cutting area of Human Performance under the Procedural Compliance aspect of the Work Practices component because the licensee failed to ensure station modification program requirements were followed in the development of post-modification testing. H.4(b)
Enforcement:
10 CFR 50, Appendix B, Criterion III, Design Control, required, in part, that design control measures shall ensure the adequacy of design be verified by the performance of a suitable testing program. EDM 601, Engineering Change Manual, required that post-modification testing for Design Changes should assure the functionality of the modified SSC. Design control measures, as implemented by EDM 601, did not ensure that the adequacy of design was verified by the performance of a suitable testing program. The post-modification testing of the new digital chart recorder installed on the SSF DG monitoring panel did not assure the modification had not adversely affected the design function of the SSF Power subsystem. As a result, the SSF DG would not have started and supplied power to the SSF following re-energization of the chart recorder. The licensee has entered this condition into the CAP as PIP O-10-3882. This apparent violation is identified as AV 05000269, 270, 287/2011002-02, Inadequate Post Modification Testing of SSF DG Modification.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors reviewed the following five post-maintenance test procedures and/or test activities to assess if:
- (1) the effect of testing on the plant had been adequately addressed by control room and/or engineering personnel;
- (2) testing was adequate for the maintenance performed;
- (3) acceptance criteria were clear and demonstrated operational readiness consistent with design and licensing basis documents;
- (4) test instrumentation had current calibrations, range, and accuracy consistent with the application;
- (5) tests were performed as written with applicable prerequisites satisfied;
- (6) jumpers installed or leads lifted were properly controlled;
- (7) test equipment was removed following testing; and
- (8) equipment was returned to the status required to perform its safety function. Documents reviewed are listed in the Attachment.
- 3B MDEFW Pump Test following motor cooler cleaning and inspection
- 2A Reactor Building Spray Pump Test following pump breaker relay PMs
- Keowee Hydro Unit 1 Guide Bearing Oil heat exchanger functional verification following cooler cleaning and eddy current testing
- Portable Chiller Power Cable Diagnostic Testing following cable replacement
b. Findings
No findings were identified.
1R20 Refueling and Outage Activities
a. Inspection Scope
Unit 1 Shutdown Due to Failure of the RCS Letdown Line Outboard CIV to Close As Required: The inspectors observed the rapid shutdown of Unit 1 on January 8, 2011, from 100 percent RTP to Mode 3, and the subsequent cooldown to Mode 5 as required by TS following the failure of the RCS letdown line outboard CIV to close. Activities observed included the unit shutdown and entry into Mode 3; cooldown to Mode 5 and placing LPI in-service; portions of the valve troubleshooting, repair, and post-maintenance testing; and review of the results from the containment walkdown performed by the licensee. The inspectors accompanied the licensee on the Mode 3 containment inspection to ensure there were no equipment issues that required resolution prior to unit restart. Inspectors reviewed items entered into the licensees CAP to ensure that the licensee had identified problems related to the forced outage at an appropriate threshold and entered them into the CAP. The inspectors also attended the licensees Plant Oversight Review Committee meeting to approve restart of the unit.
Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors either witnessed and/or reviewed test data for the four surveillance tests listed below to assess if the SSCs met TS, UFSAR, and licensee procedure requirements. In addition, the inspectors determined if the testing effectively demonstrated that the SSCs were ready and capable of performing their intended safety functions. Documents reviewed are listed in the Attachment.
Routine Surveillances
- PT/0/A/2200/012, Keowee Hydro Station Fire Protection Pump and Mulsifyre Systems Wet Surveillance
- PT/0/A/0251/010, Auxiliary Service Water Pump Test
- IP/0/A/0275/006C, Safety-Related Functional Test of the MDEFWP and Turbine Driven Emergency Feedwater Pump Initiation Pressure Switches and Cooling Water Valves In-Service Tests
- PT/1/A/0251/001, Low Pressure Service Water Pump Test
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator (PI) Verification
a. Inspection Scope
The inspectors sampled licensee data to confirm the accuracy of reported PI data for the following nine PIs for the period of January 1, 2010, through December 31, 2010. To determine the accuracy of the report PI elements, the reviewed data was assessed against PI definitions and guidance contained in Nuclear Energy Institute 99-02, Regulatory Assessment Indicator Guideline, Revision 6. Documents reviewed are listed in the Attachment.
Cornerstone: Initiating Events
- Unplanned Scrams (3 units)
- Unplanned Scrams with Complications (3 units)
- Unplanned Power Changes (3 units)
The inspectors reviewed Operating Logs, Maintenance Records, PIPs and Consolidated Derivation Entry Reports to verify the accuracy of the PI data reported for each indicator.
b. Findings
No findings were identified.
4OA2 Problem Identification and Resolution
.1 Daily Screening of Corrective Action Reports
In accordance with Inspection Procedure (IP) 71152, Problem Identification and Resolution, and in order to help identify repetitive equipment failures or specific human performance issues for follow-up, the inspectors performed daily screening of items entered into the licensees CAP. This review was accomplished by reviewing copies of PIPs, attending daily screening meetings, and accessing the licensees computerized database.
.2 Annual Sample
a. Inspection Scope
The inspectors reviewed the licensees actions following identified operating experience related to the containment particulate radiation monitoring systems inability to detect one gpm RCS leakage in one hour as assumed by the licensees Leak-Before-Break analysis. The inspectors reviewed PIPs O-04-0613, O-06-1671, and O-06-3268, and the associated corrective actions to assess the effectiveness of the actions that had been implemented to address the inability of the containment particulate radiation monitor to detect and alarm at the value assumed in the licensees leak before break analysis under certain conditions. The inspectors also reviewed the licensee response to NRC generic communications related to the issue. The enforcement aspects are discussed in Section 4OA7 of this report. The condition is documented in the licensees CAP as PIP O-11-01291. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
4OA3 Event Follow-up
.1 Inadvertent Opening of Unit 1 Turbine Bypass Valves
a. Inspection Scope
The inspectors reviewed an inadvertent opening of the 1A group of main turbine bypass valves, 1MS-19 and 1MS-22, as a result of a procedural issue used to calibrate a main condenser vacuum pressure switch. The inspectors verified the plant response was appropriate given the conditions, evaluated the effect on core thermal power, RCS, and secondary systems, and verified the plant was stable following the event. The inspectors verified no abnormal procedure entry was required. The event was documented in PIP O-11-0075, Received Operator Aid Computer alarms for Operator Aid Computer points O1D0857 (1MS-22 TURB BYPASS CONTROL B), O1D0855 (1MS-19 TURB BYPASS CONTROL A) and O1X2043. 1A (TBV) Turbine Bypass Valves (1MS-19 and 1MS-22) indicated throttled open. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2 Failure of the Unit 1 RCS Letdown Line Outboard CIV to Fully Close as Required
a. Inspection Scope
The inspectors observed the licensees response to the identification of the Unit 1 RCS letdown line outboard CIV, 1HP-5, failing to close as required. Once a clear repair path could not be identified, the unit was shut down and placed in Mode 5 as required by TS 3.6.3. The inspectors observed operator performance in the control room, verified the plant response was as expected and observed the transition onto shutdown cooling using LPI. Following repair of the valve and post maintenance testing, inspectors observed the actions to return the unit to service including plant heat-up, placing the main generator on-line and portions of power ascension. The event was documented in PIP O-11-0218. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.3 Unit 3 Downpower to Repair Through-wall Leak on Piping Near 3HD-149
a. Inspection Scope
The inspectors observed the licensees response to the identification of a through-wall leak on piping downstream of the 3B2 feedwater heater level control valve. The inspectors reviewed the licensees short term decision making following an increase in leakage and observed the licensees actions to reduce reactor power to approximately 16 percent RTP to remove the main turbine/generator from service so the leak could be repaired. The event was documented in PIP O-11-0788. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.4 Fire Detected in the Unit 1 Equipment Room
a. Inspection Scope
On February 8, 2011, workers in the Unit 1 Equipment Room reported the smell of smoke in the area to the main control room. The fire brigade was dispatched and responded promptly. Upon arrival in the Unit 1 Equipment Room, the fire brigade found smoke and a small flame coming from one of the Statalarm cards in a cabinet located in the room. The fire was extinguished in less than 15 minutes. The resident inspectors responded to the Equipment Room and observed the fire brigade performance. The inspectors reviewed the PIPs associated with the event. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.5 Unexpected Decrease in Unit 2 Letdown Storage Tank Level and Subsequent Entry Into
Abnormal Operating Procedure for Excessive RCS Leakage
a. Inspection Scope
On February 17, 2011, the licensee was preparing to perform a resin sluice of the spare Unit 1 / Unit 2 purification demineralizer prior to placing it in service and removing the normal demineralizer from service. Prior to starting the actual sluice portion of the evolution, operators in the Unit 2 main control room noted a decreasing trend in the Letdown Storage Tank level and entered the Abnormal Operating Procedure for excessive RCS leakage. The inspectors observed the licensees actions to stabilize the plant and identify the source of the leakage. The inspectors also attended follow-up meetings to assess the licensees analysis of the event and the development of actions to allow the sluice evolution to recommence and reduce elevated dose rates in areas of the Auxiliary Building resulting from the resin that had been flushed into the piping.
Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
4OA5 Other Activities
.1 Quarterly Resident Inspector Observations of Security Personnel and Activities
a. Inspection Scope
During the inspection period, the inspectors conducted observations of security force personnel and activities to ensure that the activities were consistent with licensee security procedures and regulatory requirements relating to nuclear plant security.
These observations took place during both normal and off-normal plant working hours.
These quarterly resident inspector observations of security force personnel and activities did not constitute any additional inspection samples. Rather, they were considered an integral part of the inspectors' normal plant status reviews and inspection activities.
b. Findings
No findings were identified.
.2 Operation of an ISFSI
a. Inspection Scope
Using the guidance of IP 60855.1, Operation of an Independent Spent Fuel Storage Installation at Operating Plants, the inspectors observed operations involving spent fuel storage. The inspectors reviewed documentation related to Dry Shielded Canister (DSC) 118, and verified that parameters and characteristics for each fuel assembly stored in the DSC were recorded, and that the records were maintained as controlled documents. The inspectors verified that the fuel selected for storage was consistent with the ISFSI Certificate of Compliance requirements. The inspectors also observed selected licensee activities related to the loading, vacuum drying and transfer of the DSC into the Horizontal Storage Module, to ensure procedural requirements were met. The inspectors also reviewed selected screening evaluations performed pursuant to 10 CFR 72.48 since the last inspection. There were no 72.48 evaluations performed during this period as all screenings determined no 72.48 evaluations were required.
b. Findings
No findings were identified.
4OA6 Management Meetings (Including Exit Meeting)
Exit Meeting Summary
The resident inspectors presented the inspection results to Mr. T. Preston Gillespie, Jr.,
and other members of licensee management, on April 18, 2011. The licensee acknowledged the findings presented. The inspectors asked the licensee whether any of the material examined during the inspection should be considered proprietary and no proprietary information was identified.
4OA7 Licensee Identified Violation
The following violation of very low safety significance (Green) was identified by the licensee and is a violation of NRC requirements which meet the criteria of the NRC Enforcement Policy for being dispositioned as NCVs.
- 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that conditions adverse to quality are promptly identified and corrected. Contrary to the above, from 2004 to 2011, the licensee failed to promptly identify and correct a condition adverse to quality in that TS 3.4.15, RCS Leakage Detection Instrumentation, was non-conservative. TS 3.4.15 was non-conservative because the existing radiation monitors were unable to detect the required 1 gpm leak in one hour at lower power levels through Mode 4 as required by the TS and the licensees Leak-Before-Break analysis used in the LPI Crossover Modification license amendment submittal. Examples of opportunities to identify that the TS was non-conservative included:
- (1) PIP O-04-0613, which identified that the reactor building gaseous radiation detectors were unable to meet the RG 1.45 sensitivity requirements rendering them inoperable;
- (2) PIP O-06-1671, which identified that the particulate monitors would be unable to meet leakage detection requirements at hot zero power through Mode 4 as defined in TS; and
- (3) a 2007 license amendment request to remove the reactor building gaseous radiation monitors from TS due to their inability to meet RG 1.45 sensitivity requirements. Additionally, the licensee had opportunities to identify and correct the condition as follow-up to NRC generic communications and industry operating experience in the 2005 - 2008 timeframe.
This finding is not greater than Green because the finding would not result in exceeding the TS limit for any RCS leakage and would not have affected other mitigation systems. The licensee entered the issue into their CAP as PIP O-11-1291.
ATTACHMENT:
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee
- K. Alter, Regulatory Compliance Manager
- B. Ayers, Operations Continuing Training Supervisor
- S. Batson, Station Manager
- M. Beaver, Engineering Technical Supervisor
- S. Boggs, Emergency Services Coordinator
- J. Bohlmann, Organization Effectiveness Manager
- T. Bostian, OMP/Project Manager
- E. Burchfield, Superintendent of Operations
- J. Carson, Electrical Coordinator/DZ Atlantic
- N. Clarkson, OMP-Mechanical/Procurement Engineering Supervisor
- P. Fisk, Mechanical/Civil Engineering Manager
- R. Freudenberger, Regulatory Support Manager
- P. Gillespie, Site Vice President
- T. King, Security Manager
- A. Lotfi, Civil Engineering Implementation Manager
- R. Murphy, OMP/Duke, Nuclear Senior Manager
- T. Patterson, Safety Assurance Manager
- T. Ray, Engineering Manager
- D. Robinson, Radiation Protection Manager
- J. Steely, Operations Training Manager
NRC
LIST OF REPORT ITEMS
Opened and Closed
- 05000269, 270, 287/2011002-01 NCV Inadequate Management of the Risk Associated with the Removal of the Unit 2 West Penetration Room Girts (Section 1R13)
Opened
- 05000269, 270, 287/2011002-02 AV Inadequate Post Modification Testing to Ensure SSF DG Functionality (Section 1R18)