IR 05000271/2012002
| ML12107A414 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 04/16/2012 |
| From: | Bellamy R NRC/RGN-I/DRP/PB5 |
| To: | Wamser C Entergy Nuclear Operations |
| References | |
| IR-12-002 | |
| Download: ML12107A414 (35) | |
Text
UNITED STATES ril 16, 2012
SUBJECT:
VERMONT YANKEE NUCLEAR POWER STATION - NRC INTEGRATED INSPECTION REPORT 05000271/2012002
Dear Mr. Wamser:
On March 31, 2012, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Vermont Yankee Nuclear Power Station. The enclosed inspection report documents the inspection results, which were discussed on April 16, 2012, with Mr. Michael Romeo and other members of your staff.
The inspection examined activities performed 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.
This report documents two self-revealing findings of very low safety significance (Green).
These findings were determined to involve violations of NRC requirements. However, because of the very low safety significance, and because they are entered into your corrective action program, the NRC is treating these findings as non-cited violations (NCVs), consistent with Section 2.3.2 of the NRC Enforcement Policy. If you contest any NCV in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the Nuclear Regulatory Commission, ATTN.: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Senior Resident Inspector at Vermont Yankee. In addition, if you disagree with the cross-cutting aspect assigned to any finding in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region I, and the NRC Senior Resident Inspector at Vermont Yankee.
In accordance with 10 CFR 2.390 of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of the NRCs Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web Site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Ronald R. Bellamy, Chief Reactor Projects Branch 5 Division of Reactor Projects Docket No. 50-271 License No. DPR-28
Enclosure:
Inspection Report No. 05000271/2012002 w/ Attachment: Supplemental Information
REGION I==
Docket No.: 50-271 License No.: DPR-28 Report No.: 05000271/2012002 Licensee: Entergy Nuclear Operations, Inc.
Facility: Vermont Yankee Nuclear Power Station Location: Vernon, Vermont 05354-9766 Dates: January 1, 2012 through March 31, 2012 Inspectors: S. Rutenkroger, Ph.D, Senior Resident Inspector S. Rich, Resident Inspector E. Burket, Reactor Inspector, Division of Reactor Safety (DRS)
E. Keighley, Reactor Inspector, Division of Reactor Projects (DRP)
K. Dunham, Reactor Inspector, DRP Approved by: Ronald R. Bellamy, Chief Reactor Projects Branch 5 Division of Reactor Projects Enclosure
SUMMARY OF FINDINGS
IR 05000271/2012002; 01/01/2012 - 03/31/2012; Vermont Yankee Nuclear Power Station;
Maintenance Effectiveness, Post-Maintenance Testing.
This report covered a three-month period of inspection by resident inspectors and announced inspections by regional inspectors. Two self-revealing findings of very low safety significance (Green), which were characterized as non-cited violations (NCVs), are documented in this report. The significance of most findings is indicated by their color (Green, White, Yellow, Red)using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP). The cross-cutting aspects for the findings were determined using IMC 0310, Components Within 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 NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 4, dated December 2006.
Cornerstone: Mitigating Systems
- Green.
A self-revealing, Green, NCV of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, was identified because Entergy did not promptly correct an adverse condition resulting in the failure of the B uninterruptible power supply (UPS) motor generator (MG)set direct current (DC) tachometer coupling. Specifically, Entergy personnel did not promptly replace or verify the physical condition of the B tachometer coupling when it was known that it was aged and susceptible to age-related failure. Entergys corrective actions included replacing the B tachometer coupling, establishing a 12 year preventive maintenance replacement frequency, and initiating CR-VTY-2011-03686, CR-VTY-2011-03744, CR-VTY-2011-05335, CR-VTY-2011-05337, and CR-VTY-2012-01096.
The inspectors determined that the issue was more than minor because it is associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability and reliability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the B UPS MG set failed in service, affecting the overall system redundancy and reliability, and resulted in 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of unplanned unavailability. The inspectors determined the significance of the finding using IMC 0609.04, Phase 1 - Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green)because it did not represent a loss of system safety function, a loss of safety function of a single train for greater than its technical specification (TS) allowed outage time (UPS-1B),
and did not screen as potentially risk significant due to external initiating events. The inspectors determined that the finding had a cross-cutting aspect in the Human Performance cross-cutting area, Decision-Making component, because Entergy personnel did not use conservative assumptions in decision making and did not adopt a requirement to demonstrate that the proposed action to delay the coupling replacement until June 2012 was safe. H.1(b). (Section 1R12)
- Green.
A self-revealing, Green, NCV of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, was identified because Entergy personnel did not promptly correct an adverse condition resulting in the unplanned unavailability of the D service water pump.
Specifically, Entergy personnel did not maintain a clear oil sight glass and did not identify a low oil level for the upper motor bearing prior to damage to the bearing. Entergys corrective actions included initiating CR-VTY-2012-00483, performing an apparent cause evaluation (ACE), and replacing the motor and sight glass. Entergy staff completed the D service water pump work and restored it to service.
The inspectors determined that the issue was more than minor because it is associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability and reliability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the D service water pump failed in service affecting overall safety system redundancy and reliability, and resulted in three days of unplanned unavailability. The inspectors determined the significance of the finding using IMC 0609.04, Phase 1 - Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green) because it did not represent a loss of system safety function, a loss of safety function of a single train for greater than its TS allowed outage time, and did not screen as potentially risk significant due to external initiating events. The inspectors determined that this finding had a cross-cutting aspect in the Problem Identification and Resolution cross-cutting area, Corrective Action Program component, because Entergy personnel did not implement a corrective action program with a low threshold for identifying issues and as a result, the stained sight glass was not recognized as an adverse condition
P.1(a). (Section 1R19)
REPORT DETAILS
Summary of Plant Status
Vermont Yankee Nuclear Power Station (VY) began the inspection period at 100 percent power.
On January 30, operators reduced power to 19 percent to perform a control rod pattern adjustment, troubleshoot the main condenser, and reopen a turbine stop valve when it did not open by normal means after testing. Operators returned VY to 100 percent power on February 3. On March 5, operators reduced power to 39 percent to remove scaffolding in the main condenser and returned VY to 100 percent power on March 6. On March 27, operators reduced power to 30 percent to perform work to improve heat transfer in the main condenser.
Operators returned VY to 100 percent power on March 30. VY remained at or near 100 percent power for the remainder of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity
1R01 Adverse Weather Protection
.1 Impending Adverse Weather
a. Inspection Scope
The inspectors performed a review of Entergys procedures to evaluate their process for preparing for cold weather. This review was conducted on February 13 due to forecasted low temperatures. The inspectors reviewed the actions specified in OPOP-PHEN-3127, Natural Phenomena, and OPOP-PREP-2196, Seasonal Preparedness.
The inspectors also performed a walkdown of indoor and outdoor areas containing safety related equipment to verify that the appropriate equipment was staged, that freeze protection systems were functional and that indoor temperatures were not low enough to impact equipment operability. Documents reviewed for each section of this inspection report are listed in the Attachment.
b. Findings
No findings were identified.
.2 External Flooding
a. Inspection Scope
During the week of February 21, the inspectors performed an inspection of the external flood protection measures for Vermont Yankee. The inspectors reviewed the Individual Plant Examination for External Events, which depicted the design flood levels and protection areas containing safety-related equipment to identify areas that may be affected by external flooding. The inspectors conducted a general site walkdown of all external areas of the plant, including the intake structure and control building to ensure that Entergy was capable of performing flood control measures described in operating procedures. The inspectors verified that those measures were adequate to protect against external flooding events. The inspectors also reviewed Vermont Yankees emergency action levels for flooding to determine if they were appropriate.
b. Findings
No findings were identified.
1R04 Equipment Alignment
.1 Partial System Walkdowns
a. Inspection Scope
The inspectors performed partial walkdowns of the following systems:
- B core spray during B residual heat removal maintenance on January 25
- B emergency diesel generator (EDG), following a 6 month fast start to ensure the equipment was properly restored to a standby lineup, on March 21
- A and B main station batteries during A EDG maintenance on February 27 The inspectors selected these systems based on their risk-significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors reviewed applicable operating procedures, system diagrams, the updated final safety analysis report (UFSAR), TS, condition reports (CRs), and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted system performance of their intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. The inspectors also reviewed whether Entergy staff had properly identified equipment issues and entered them into the corrective action program for resolution with the appropriate significance characterization.
Findings No findings were identified.
.2 Full System Walkdown
a. Inspection Scope
The inspectors performed a complete system walkdown of accessible portions of the standby gas treatment system to verify the existing equipment lineup was correct. The inspectors reviewed operating procedures, drawings, equipment line-up check-off lists, and the UFSAR to verify the system was aligned to perform its required safety functions.
The inspectors also reviewed electrical power availability, hanger and support functionality, and functionality of support systems. The inspectors performed field walkdowns of accessible portions of the system to verify system components and support equipment were aligned correctly and operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. Additionally, the inspectors reviewed a sample of related CRs and work orders to ensure Entergy appropriately evaluated and resolved any deficiencies. The inspectors discussed the systems condition with the system engineer.
b. Findings
No findings were identified.
1R05 Fire Protection
.1 Resident Inspector Quarterly Walkdowns
a. Inspection Scope
The inspectors conducted tours of the areas listed below to assess the material condition and operational status of fire protection features. The inspectors verified that Entergy controlled combustible materials and ignition sources in accordance with administrative procedures. The inspectors verified that fire protection and suppression equipment was available for use as specified in the area pre-fire plan, and passive fire barriers were maintained in good material condition. The inspectors also verified that station personnel implemented compensatory measures for out of service, degraded, or inoperable fire protection equipment, in accordance with procedures.
- Reactor building 303 elevation, on January 11
- Reactor building 318 elevation, on January 12
- Southeast corner room 213 and 232 elevations, on January 25
- Emergency diesel generator rooms A and B, on February 9
- Reactor building 345, on March 21
- East and west switchgear rooms, on March 22
b. Findings
No findings were identified.
.2 Fire Protection - Drill Observation
a. Inspection Scope
The inspectors observed a fire brigade drill scenario conducted on March 22 that involved a fire in the isophase bus ducts in the Turbine Building. The inspectors evaluated the readiness of the plant fire brigade to fight fires. The inspectors verified that Entergy personnel identified deficiencies, openly discussed them in a self-critical manner at the debrief, and took appropriate corrective actions as required. The inspectors verified that the fire brigade:
- Properly used turnout gear and self-contained breathing apparatus
- Properly used and laid out fire hoses
- Employed appropriate fire-fighting techniques
- Brought sufficient fire-fighting equipment to the scene
- Effectively used command and control
- Searched for victims and for propagation of the fire into other plant areas
- Conducted smoke removal operations
- Properly used pre-planned strategies
- Adhered to the pre-planned drill scenario
- Met drill objectives The inspectors also evaluated the fire brigades actions to determine whether these actions were in accordance with Entergys fire-fighting strategies.
b. Findings
No findings were identified.
1R06 Flood Protection Measures
Internal Flooding Review
a. Inspection Scope
The inspectors reviewed the UFSAR, the site flooding analysis, and plant procedures to assess susceptibilities involving internal flooding. The inspectors also reviewed the corrective action program to determine if Entergy identified and corrected flooding problems and whether operator actions for coping with flooding were adequate. The inspectors focused on Reactor Building 280' elevation to verify the adequacy of equipment seals located below the flood line, floor and water penetration seals, common drain lines and sumps, sump pumps, level alarms, control circuits, and temporary or removable flood barriers.
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification Program
.1 Quarterly Review of Licensed Operator Requalification Testing and Training
a. Inspection Scope
The inspectors observed licensed operator simulator training on March 5 and March 19, which included the failure of the reactor water cleanup line isolation valves to close coincident with a line break. The inspectors evaluated operator performance during the simulated event and verified completion of risk significant operator actions, including the use of abnormal and emergency operating procedures. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and degrading plant conditions, and the oversight and direction provided by the control room supervisor. The inspectors verified the accuracy and timeliness of the emergency classification made by the shift manager and shift technical advisor and the TS action statements entered. Additionally, the inspectors assessed the ability of the crew and training staff to identify and document crew performance problems.
b. Findings
No findings were identified.
.2 Quarterly Review of Licensed Operator Performance in the Main Control Room
a. Inspection Scope
The inspectors observed control room operators during a power reduction on January 30 for a control rod pattern adjustment and main condenser vacuum troubleshooting. The inspectors observed pre-shift briefings and reactivity control briefings to verify that roles and responsibilities, critical steps, expected results and hold points were discussed. The inspectors verified that procedure use, crew communications, and response to alarms met established expectations and standards.
VY entered the period of extended operations with a renewed license on March 22. In order to verify that the control room operators maintained the proper focus on safe plant operation, and were not distracted by external events such as planned protests, the inspectors provided 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> onsite coverage. The inspectors determined that the plant was operated safely and there were no distractions that affected control room operator performance.
b. Findings
No findings were identified.
1R12 Maintenance Effectiveness
a. Inspection Scope
The inspectors reviewed the samples listed below to assess the effectiveness of maintenance activities on structures, systems and components (SSC) performance and reliability. The inspectors reviewed system health reports, corrective action program documents, and maintenance rule basis documents to ensure that Entergy was identifying and properly evaluating performance problems within the scope of the maintenance rule. For each sample selected, the inspectors verified that the SSC was properly scoped into the maintenance rule in accordance with 10 CFR 50.65 and verified that the (a)(2) performance criteria established by Entergy staff were reasonable.
Additionally, the inspectors ensured that Entergy staff was identifying and addressing common cause failures that occurred within and across maintenance rule system boundaries.
- 400 V DC
- 480 V alternating current (AC)
- Hydraulic control units
b. Findings
Introduction.
A self-revealing, Green, NCV of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, was identified because Entergy did not promptly correct an adverse condition resulting in the failure of the B UPS MG set DC tachometer coupling.
Specifically, Entergy personnel did not promptly replace or verify the physical condition of the B tachometer coupling when it was known that it was aged and susceptible to age-related failure.
Description.
On September 14, 2011, Entergy personnel received an A UPS MG set, UPS-1A, trouble alarm in the control room. Entergy personnel discovered that the DC tachometer had failed. UPS-1A and UPS-1B are normally operating 480 volt rotating uninterruptible power supplies consisting of a battery and a MG unit that provide the safety related (i.e. on a loss of offsite power) AC power to motor operated low pressure coolant injection valves and recirculation pump suction and discharge valves.
Entergy personnel determined that the tachometer coupling had failed. The tachometer coupling transmits torque from the DC motor shaft to the tachometer-generator shaft which provides input for DC motor speed control. The coupling is a flexible drive consisting of a steel hub and polyurethane body (an elastomer). The failed coupling had been in service since October 1990, when the entire associated MG set was installed.
Entergy staff determined there were no inspections or periodic preventive maintenance requirements established for the coupling since the vendors equipment manual only discussed annual maintenance requirements and therefore did not identify the coupling as a maintenance item. However, Entergy personnel determined that the coupling, by virtue of being constructed of an elastomer, was vulnerable to age-related degradation resulting in inflexibility and embrittlement, followed by fatigue failure.
During the extent of condition review for the UPS-1A failure, Entergy personnel identified that the B UPS MG sets tachometer coupling had also been in service since October 1990 and was subject to the same aging vulnerability. Entergy staff initiated corrective actions to include replacement of the B coupling in the refueling outage beginning October 8, 2011. However, on October 30, Entergy personnel canceled the requested scope addition and scheduled the replacement of the coupling in the next planned B UPS maintenance window in June 2012.
On November 19, Entergy personnel received a B MG set trouble alarm in the control room. Entergy personnel determined that the DC tachometer coupling of UPS-1B had failed in service due to the same age related degradation previously identified on the A MG set tachometer coupling. Entergy personnel replaced the failed coupling and returned the B UPS to service on November 20, resulting in 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of unplanned unavailability of the B UPS and the low pressure coolant injection function of the A and B residual heat removal pumps. Entergy staff subsequently determined the couplings have a shelf life of 23.25 years, based upon the polymer material used.
Entergy staff determined a replacement frequency for service life of 12 years based on half the shelf life due to both A and B failures after approximately 20 years in service.
The shelf life indicates an overall maximum acceptable age for the product from the date of manufacture considering the item is properly stored prior to installation. For example, elastomers are stored in a strain free, unstressed state with no twists, bends, or folds.
The service life represents the maximum time the component should be in service subject to the normal stresses involved with performing its function. The time the component is in storage plus the time the component is in service should be less than the shelf life. In this case, both tachometer couplings were in service for a time longer than a reasonable service life.
The inspectors reviewed the circumstances associated with both failures and Entergys documented basis for not completing the B coupling replacement during the RFO and assessed the adequacy and timeliness of Entergys corrective actions. The inspectors determined that Entergys actions were not adequate given that the B coupling had exceeded a reasonable service life; the documented basis for deferral of the corrective action did not provide a rationale for why the B coupling would be expected to not fail prior to June 2012; and no interim checks were established to ensure the B coupling would not fail in service, such as verifying the plasticity of the coupling.
Entergys corrective actions included replacing the B tachometer coupling, establishing a 12 year preventive maintenance replacement frequency, and initiating CR-VTY-2011-
===03686, CR-VTY-2011-03744, CR-VTY-2011-05335, CR-VTY-2011-05337, and CR-VTY- 2012-01096.
Analysis.
The inspectors determined that Entergy personnels decision not to replace the B UPS MG set tachometer coupling prior to its failure in service without an interim check of its physical condition was a performance deficiency that was reasonably within Entergys ability to foresee and correct and should have been prevented. Traditional enforcement does not apply since there were no actual safety consequences, impacts on the NRCs ability to perform its regulatory function, or willful aspects of the finding.
The inspectors reviewed NRC Inspection Manual Chapter (IMC) 0612, Appendix E, Examples of Minor Issues, and found that there were no sufficiently similar examples to the issue. The inspectors determined that the issue was more than minor because it is associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability and reliability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the B UPS MG set failed in service, affecting the overall system redundancy and reliability, and resulted in 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> of unplanned unavailability. The inspectors determined the significance of the finding using IMC 0609.04, Phase 1 - Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green) because it did not represent a loss of system safety function, a loss of safety function of a single train for greater than its TS allowed outage time (UPS-1B), and did not screen as potentially risk significant due to external initiating events.
The inspectors determined that the finding had a cross-cutting aspect in the Human Performance cross-cutting area, Decision-Making component, because Entergy personnel did not use conservative assumptions in decision making and did not adopt a requirement to demonstrate that the proposed action to delay the coupling replacement until June 2012 was safe. H.1(b)
Enforcement.
10 CFR 50 Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected. Contrary to the above, on October 30, 2011, Entergy failed to promptly correct the deficient B UPS MG set tachometer coupling, which later resulted in its failure. Entergys corrective action to restore compliance consisted of replacing the B coupling after its failure. Because this violation was of very low safety significance and was entered into the corrective action program (CR-VTY-2011-03686, CR-VTY-2011-03744, CR-VTY-2011-05335, CR-VTY-2011-05337, and CR-VTY-2012-01096), this violation is being treated as an NCV, consistent with the NRC Enforcement Policy. (NCV 05000271/2012002-01, Failure of the B UPS Tachometer Coupling Due to Age and Inadequate Corrective Actions)
1R13 Maintenance Risk Assessments and Emergent Work Control
a. Inspection Scope
The inspectors reviewed station evaluation and management of plant risk for the maintenance and emergent work activities listed below to verify that Entergy performed the appropriate risk assessments prior to removing equipment for work. The inspectors selected these activities based on potential risk significance relative to the reactor safety cornerstones. As applicable for each activity, the inspectors verified that Entergy personnel performed risk assessments as required by 10 CFR 50.65(a)(4) and that the assessments were accurate and complete. When Entergy performed emergent work, the inspectors verified that operations personnel promptly assessed and managed plant risk. The inspectors reviewed the scope of maintenance work and discussed the results of the assessment with the stations probabilistic risk analyst to verify plant conditions were consistent with the risk assessment. The inspectors also reviewed the TS requirements and inspected portions of redundant safety systems to verify risk analysis assumptions were valid and applicable requirements were met.
- B residual heat removal heat exchanger maintenance - workweek (WW) 1204
- Emergent work on D service water pump - WW 1205
- A emergency diesel generator maintenance - WW 1209
- B emergency diesel generator fast start surveillance - WW 1211
b. Findings
No findings were identified.
1R15 Operability Evaluations
a. Inspection Scope
The inspectors reviewed operability determinations for the following degraded or non-conforming conditions:
- Control rod 26-39 failed to move out from position 46 to 48 using notch override, CR initiated on January 8
- Hale portable pump starting battery degraded, CR initiated on February 5
- B emergency diesel generator lube oil tank level below the level required by procedure, CR initiated on February 15
- Air void in A core spray discharge pipe, CR initiated on February 24
- B EDG inspection port cover studs replaced with bolts, CR initiated on March 1
- Two sections of deck plates were identified inside the main condenser that had been installed in the last RFO and not removed, CR initiated on March 5
- Limited procedural guidance on service water operability based on high and low river levels, CR initiated on March 6
- Yoke bushing stripped on a B standby liquid control pump accumulator drain valve, CR initiated on March 14 The inspectors selected these issues based on the risk significance of the associated components and systems. The inspectors evaluated the technical adequacy of the operability determinations to assess whether TS operability was properly justified and the subject component or system remained available such that no unrecognized increase in risk occurred. The inspectors compared the operability and design criteria in the appropriate sections of the TS and UFSAR to Entergys evaluations to determine whether the components or systems were operable. The inspectors determined compliance with bounding limitations associated with the evaluations.
b. Findings
No findings were identified.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors reviewed the post-maintenance tests for the maintenance activities listed below to verify that procedures and test activities ensured system operability and functional capability. The inspectors reviewed the test procedure to verify that the procedure adequately tested the safety functions that may have been affected by the maintenance activity, that the acceptance criteria in the procedure were consistent with the information in the applicable licensing basis and/or design basis documents, and that the procedure had been properly reviewed and approved. The inspectors also witnessed the test or reviewed test data to verify that the test results adequately demonstrated restoration of the affected safety functions.
- Control rod drive pump oil change and filter replacement on January 18
- B residual heat removal heat exchanger cleaning and inspection on January 27
- D service water pump motor bearing replacement on February 3
- Hale portable pump battery replacement on February 14-16
- A EDG jacket water system maintenance on March 1
b. Findings
Introduction.
A self-revealing, Green, NCV of 10 CFR 50 Appendix B, Criterion XVI, Corrective Action, was identified because Entergy personnel did not promptly correct an adverse condition resulting in the unplanned unavailability of the D service water pump. Specifically, Entergy personnel did not maintain a clear oil sight glass and did not identify a low oil level for the upper motor bearing prior to damage to the bearing.
Description.
On January 31, an Entergy auxiliary operator (AO) conducting rounds heard an unusual oscillating noise emanating from the upper bearing area of the D service water pump motor with the pump running. The AO looked at the oil level displayed in the sight glass and initially observed a normal level. However, upon closer examination the AO recognized that the sight glass was stained up to the normal oil level and no oil was present within the sight glass. The AO reported the information to the control room operators who immediately shut down the pump. The AO then observed smoke coming from the top of the motor. Entergy staff took a sample from the remaining oil and sent the sample for laboratory analysis. The analysis indicated that the oil was severely degraded and bearing damage had occurred. Entergy personnel replaced the motor.
The service water system, which includes four service water pumps, supplies cooling water to various loads such as the emergency diesel generator jacket water coolers, the emergency core cooling system room ventilation coolers, and the residual heat removal service water (RHRSW) system. The upper bearing for the D service water pump motor requires oil lubrication. The AOs visually verify the oil level displayed in the sight glasses every shift during rounds.
Entergy staff performed an apparent cause evaluation (ACE) and determined the following history. On November 23, 2009, a work request was generated that identified the D service water pump sight glass as being dirty and cloudy, but Entergy staff did not generate an associated condition report (CR). A work order was not issued until February 1, 2012, after the bearing was damaged, because the work request was categorized as to be worked only when time allows. On December 9, 2009, Entergy personnel initiated CR-VTY-2009-04282, documenting that the oil level was found excessively low due to a shadow line being present in the sight glass. Entergy staff classified CR-VTY-2009-04282 as D - Actions Taken on December 10, 2009, documenting the actions taken as, oil added to restore level, which did not address the condition of the sight glass. As a result, the D service water pump sight glass remained stained such that the stain appeared to be the oil level, and the real oil level could only be determined by using a special technique, which was not generally recognized by Entergy personnel. Entergy operators placed the D service water pump in service on October 28, 2011, and the oil slowly depleted as the pump ran continuously until low oil caused bearing damage on January 31, 2012.
Entergys corrective actions included initiating CR-VTY-2012-00483, performing an ACE, and replacing the motor and sight glass. Entergy staff completed the D service water pump work and restored it to service on February 3.
Analysis.
The inspectors determined that Entergys failure to maintain a proper oil level for the upper motor bearing of the D service water pump was a performance deficiency that was reasonably within Entergys ability to foresee and correct and should have been prevented. Traditional enforcement does not apply since there were no actual safety consequences, impacts on the NRCs ability to perform its regulatory function, or willful aspects of the finding.
The inspectors reviewed NRC Inspection Manual Chapter (IMC) 0612, Appendix E, Examples of Minor Issues, and found that there were no sufficiently similar examples to the issue. The inspectors determined that the issue was more than minor because it is associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability and reliability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, the D service water pump failed in service affecting overall safety system redundancy and reliability and resulted in three days of unplanned unavailability.
The inspectors determined the significance of the finding using IMC 0609.04, Phase 1 -
Initial Screening and Characterization of Findings. The finding was determined to be of very low safety significance (Green) because it did not represent a loss of system safety function, a loss of safety function of a single train for greater than its TS allowed outage time, and did not screen as potentially risk significant due to external initiating events.
The inspectors determined that this finding had a cross-cutting aspect in the Problem Identification and Resolution cross-cutting area, Corrective Action Program component, because Entergy personnel did not implement a corrective action program with a low threshold for identifying issues and as a result, the stained sight glass was not recognized as an adverse condition. P.1(a)
Enforcement.
10 CFR 50 Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. Contrary to the above, from December 9, 2009, to January 31, 2012, Entergy personnel failed to promptly identify and correct a stained sight glass and detect a low oil condition on the D service water pump motor. Entergys corrective action to restore compliance consisted of promptly replacing the D service water pump motor and sight glass.
Because this violation was of very low safety significance and was entered into the corrective action program (CR-VTY-2012-00483), this violation is being treated as an NCV, consistent with the NRC Enforcement Policy. (NCV 05000271/2012002-02, Failure of the D Service Water Pump Due to Low Oil and Inadequate Corrective Actions)
1R22 Surveillance Testing
a. Inspection Scope
The inspectors observed performance of surveillance tests and reviewed test data of selected risk-significant SSCs to assess whether test results satisfied TS, the UFSAR, and Entergys procedure requirements. The inspectors verified that test acceptance criteria were clear, tests demonstrated operational readiness and were consistent with design documentation, test instrumentation had current calibrations and the range and accuracy for the application, tests were performed as written, and applicable test prerequisites were satisfied. Upon test completion, the inspectors considered whether the test results supported that equipment was capable of performing the required safety functions. The inspectors reviewed the following surveillance tests:
- Turbine valve testing on January 30
- High reactor pressure recirculation pump trip and alternate rod insertion functional test on February 6
- Reactor core isolation cooling valve surveillance on February 10 (in-service test)
- Torus to drywell vacuum breakers breakaway and opening test on February 15 (in-service test)
- Undervoltage relay testing on March 1
- Turbine control valve fast closure scram surveillance on March 7
- RCS leak detection surveillance on March 22 (reactor coolant system)
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP6 Drill Evaluation
.1 Emergency Preparedness Drill Observation
a. Inspection Scope
The inspectors evaluated the conduct of a routine emergency drill on March 14 to identify any weaknesses and deficiencies in the classification, notification, and protective action recommendation development activities. The inspectors observed emergency response operations in the simulator and emergency operations facility to determine whether the event classification, notifications, and protective action recommendations were performed in accordance with procedures. The inspectors also attended the emergency operations facility drill critique to compare inspector observations with those identified by Entergy staff in order to evaluate Entergys critique and to verify that Entergy staff was properly identifying weaknesses and entering them into the corrective action program.
b. Findings
No findings were identified.
.2 Training Observations
a. Inspection Scope
The inspectors observed simulator training for licensed operators on March 5 and March 19 which required emergency plan implementation by an operations crew. Entergy evaluated and included this evolution in performance indicator (PI) data regarding drill and exercise performance. The inspectors observed event classification and notification activities performed by the crew. The inspectors also attended the post-evolution critique for the scenario. The focus of the inspectors activities was to note any weaknesses and deficiencies in the crews performance and ensure that Entergy evaluators noted the same issues and entered them into the corrective action program.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator (PI) Verification
Initiating Events Cornerstone ===
a. Inspection Scope
The inspectors reviewed Entergys submittals and PI data for the indicators listed below for the period from January 2011 to December 2011. The inspectors reviewed selected operator logs and plant process computer data. The PI definitions and guidance contained in Nuclear Energy Institute (NEI) 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6 and AP 0094, NRC Performance Indicator Reporting, Revision 16, were used to verify the accuracy and completeness of the PI data reported during this period. The PIs reviewed were:
- Unplanned scrams per 7000 critical hours
- Unplanned power changes per 7000 critical hours
- Unplanned scrams with complications
b. Findings
No findings were identified.
4OA2 Problem Identification and Resolution
.1 Routine Review of Problem Identification and Resolution Activities
a. Inspection Scope
As required by Inspection Procedure 71152, Problem Identification and Resolution, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify that Entergy entered issues into their corrective action program at an appropriate threshold, gave adequate attention to timely corrective actions, and identified and addressed adverse trends. In order to assist with the identification of repetitive equipment failures and specific human performance issues for follow-up, the inspectors performed a daily screening of items entered into the corrective action program and periodically attended condition report review group meetings.
b. Findings
No findings were identified.
.2 Annual Sample: Review of the Operator Workaround Program
a. Inspection Scope
The inspectors reviewed the cumulative effects of the existing operator workarounds, operator burdens, existing operator aids and disabled alarms, and open main control room deficiencies to identify any effect on emergency operating procedure operator actions, and any impact on possible initiating events and mitigating systems. The inspectors evaluated whether station personnel had identified, assessed, and reviewed operator workarounds as specified in Vermont Yankee procedure DP 0166, Operations Department Standards, Revision 23.
The inspectors reviewed Entergys process to identify, prioritize and resolve main control room distractions to minimize operator burdens. The inspectors reviewed the system used to track these operator workarounds and recent Entergy self assessments of the program. The inspectors also toured the control room and discussed the current operator workarounds with the operators to ensure the items were being addressed on a schedule consistent with their relative safety significance.
b. Findings and Observations
No findings were identified.
The inspectors determined that the issues reviewed did not adversely affect the capability of the operators to implement abnormal or emergency operating procedures.
The inspectors also verified that Entergy entered operator workarounds and burdens into the corrective action program at an appropriate threshold and planned or implemented corrective actions commensurate with their safety significance.
.3 Annual Sample: Foreign Material Exclusion Controls
a. Inspection Scope
The inspectors performed a review of Entergys corrective actions associated with issues concerning foreign material exclusion (FME) controls to determine if they were reasonable to correct the identified causes and prevent recurrence of the problems.
Specifically, the inspectors reviewed actions taken to address NCV 05000271/2011002-01, regarding the failure to follow the FME procedure (CR-VTY-2011-00007) while replacing the C RHRSW pump in December, 2010. The inspectors also reviewed the actions taken to address the FME program trend review (CR-VTY-2011-04537 and CR-VTY-2011-04892) of the most recent RFO in the fall of 2011. The trend review identified weaknesses in the FME program implementation, specifically in the areas of worker practices, monitor effectiveness, and program application.
The inspectors reviewed procedures, work orders, training documents, CRs, and ACEs to assess the appropriateness of Entergys corrective actions. The inspectors discussed with plant personnel the short and long term corrective actions and the extent-of-condition reviews to determine whether Entergy was appropriately identifying, characterizing, and correcting problems associated with these issues and whether the planned or completed corrective actions were suitable. Additionally, the inspectors interviewed personnel qualified as FME monitors and FME workers to assess the effectiveness of the implemented corrective actions.
b. Findings and Observations
No findings were identified.
The inspectors concluded that the ACEs performed by Entergy had appropriately characterized the causes of the FME event for the C RHRSW pump replacement and the RFO-29 FME trend review. Entergy identified distinct apparent and contributing causes for each ACE performed. The inspectors determined that Entergy implemented suitable and timely corrective actions to address the identified causes. The corrective actions included updating continuing training lesson plans, revising work orders to include identification of critical steps, and working with the FME industry working group to establish guidelines to improve FME monitor effectiveness. The inspectors noted that future corrective actions associated with the RFO FME trend review included effectiveness reviews of the apparent causes following the next RFO.
4OA3 Follow-Up of Events and Notices of Enforcement Discretion
(Closed) Licensee Event Report (LER) 05000271/2011-002-00: Inoperability of Both Emergency Diesel Generators due to a Lack of Adherence to Procedures On December 2, 2011, Entergy personnel mistakenly tripped the A emergency diesel generator (EDG) fuel rack instead of the B EDG fuel rack. This resulted in both EDGs being inoperable at the same time. The condition was immediately identified by operations personnel due to alarms received in the main control room, and the A EDG was returned to an operable status in two minutes.
The inspectors reviewed the LER and related documents with respect to the accuracy and appropriateness of the LER and corrective actions. NRC inspection report 05000271/2011005 previously documented a finding that Entergy personnel used instructions that were not appropriate to the circumstances, resulting in an inadvertent trip of the A EDG fuel rack. No additional findings were identified during this review.
This LER is closed.
4OA6 Meetings, including Exit
On April 16, 2012, the inspectors presented the inspection results to Mr. Michael Romeo, Director of Nuclear Safety Assurance, and other members of the Vermont Yankee Nuclear Power Plant staff. The inspectors verified that no proprietary information was retained by the inspectors or documented in this report.
ATTACHMENT:
SUPPLEMENTARY INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- C. Wamser, Site Vice President
- M. Gosekamp, General Manager of Plant Operations
- M. Romeo, Director of Nuclear Safety Assurance
- R. Wanczyk, Licensing Manager
- N. Rademacher, Director of Engineering
- J. Rogers, Design Engineering Manager
- J. Merkle, System Engineering Manager
- P. Ryan, Security Manager
- D. Jones, Operations Manager
- V. Ferrizzi, Asst. Operations Manager
- R. Busick, Asst. Operations Manager
- E. Harms, Asst. Operations Manager
- M. Tessier, Maintenance Manager
- M. McKenney, Emergency Preparedness Manager
- J. Hardy, Chemistry Manager
- P. Corbett, Quality Assurance Manager
- S. Naeck, Outage Manager
- J. Bengtson, CA&A Manager
- D. Tkatch, Radiation Protection Manager
- C. Daniels, Maintenance Manager
- M. Castronova, Manager of Projects
- R. Heathwaite, Chemistry Supervisor
- R. Current, Sr. Electrical I&C System Engineer
- L. Doucette, System Engineer
- J. Devincentis, Licensing Engineer
- M. Morgan, Technical Training Superintendent
- M. Anderson, Fire Protection Engineer
- M. Pletcher, Shift Technical Advisor
- M. Palionis, PRA Engineer
- M. Janus, Electrical Superintendent
- N. Roark, System Engineer
- J. Stasolla, Maintenance Rule Engineer
- K. Swanger, Senior Project Manager
- T. Cappelletti, Mechanical Maintenance Superintendent
- M. Prusak, Mechanical Maintenance Supervisor
- B. Buteau, State Liaison Engineer
- B. Hall, Senior Assessor
- D. Jeffries, System Engineering Supervisor
- R. Power, Program & Components Engineer
- S. Howe, Electrical Maintenance Supervisor
- B. Mully, Field Support Supervisor
- K. Murphy, Control Room Supervisor
- M. Jurkowski, Mechanical Maintenance Supervisor
- G. Bacala, Control Room Supervisor
- V. Roll, Field Support Supervisor
- N. Jennison, Shift Manager
- D. Bruce, Radiation Protection Supervisor
- J. Taylor, Operations Requalification Training Superintendent
LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Opened/Closed
- 05000271/2012002-01 NCV Failure of the B UPS Tachometer Coupling Due to Age and Inadequate Corrective Actions (Section 1R12)
- 05000271/2012002-02 NCV Failure of the D Service Water Pump Due to Low Oil and Inadequate Corrective Actions (Section 1R19)
Closed
- 05000271/2011-002-00 LER Inoperability of Both Emergency Diesel Generators due to a Lack of Adherence to Procedures (Section 4OA3)