IR 05000482/2014005
| ML15042A388 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 02/10/2015 |
| From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
| To: | Heflin A Wolf Creek |
| O'Keefe N | |
| References | |
| IR 2014005 | |
| Download: ML15042A388 (37) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION IV 1600 E. LAMAR BLVD.
ARLINGTON, TX 76011-4511 February 10, 2015 Adam C. Heflin, President and Chief Executive Officer Wolf Creek Nuclear Operating Corporation P.O. Box 411 Burlington, KS 66839 SUBJECT: WOLF CREEK GENERATING STATION - NRC INSPECTION REPORT 05000482/2014005
Dear Mr. Heflin:
O n December 31, 2014, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Wolf Creek Generating Station. O n January 8, 2015, the NRC inspectors discussed the results of this inspection with you and other members of your staff. Inspectors documented the results of this inspection in the enclosed inspection report.
NRC inspectors documented one finding of very low safety significance (Green) in this report
. The finding did not involve a violation of NRC requirements.
If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region IV; and the NRC resident inspector at the Wolf Creek Generating Station. In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, "Public Inspections, Exemptions, Requests for Withholding,"
a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC's Public Document Room or from the Publicly Available Records (PARS) component of the NRC's Agencywide Document s 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/ Neil O'Keefe, Chief Project Branch B Division of Reactor Projects
SUNSI Review By: NOKeefe ADAMS Yes No Publicly Available Non-Publicly Available Non-Sensitive Sensitive OFFICE SRI:DRP/B ASRI:DRP/B RI:DRP/B C:DRS/EB1 C:DRS/EB2 C:DRS/OB C:DRS/PSB1 NAME CPeabody DDodson RStroble ERuesch GWerner VGaddy MHaire SIGNATURE /RA/T-NFO /RA/E-NFO /RA/T-NFO /RA/GGeorge for /RA/VGaddy for /RA/ /RA/JLarsen for DATE 1/26/15 1/26/15 1/27/15 1/29/15 1/27/15 1/27/15 OFFICE C:DRS/PSB2 C:DRS/TSB C:DRP/B NAME HGepford GMiller NOKeefe SIGNATURE /RA/ /RA/ /RA/ DATE 1/27/15 1/23/15 2/10/15 Letter to Adam from Neil O'Keefe dated February 10, 2015 SUBJECT: WOLF CREEK GENERATING STATION
- NRC INSPECTION REPORT 05000 482/2014005 AND EXERCISE OF ENFORCEMENT DISCRETION Electronic distribution by RIV
- Regional Administrator (Marc.Dapas@nrc.gov)
Deputy Regional Administrator (Kriss.Kennedy@nrc.gov) DRP Director (Troy.Pruett@nrc.gov)
Acting DRP Deputy Director (Thomas.Farnholtz@nrc.gov)
DRS Director (Anton.Vegel@nrc.gov)
DRS Deputy Director (Jeff.Clark@nrc.gov)
Acting Senior Resident Inspector (Douglas.Dodson@nrc.gov)
Senior Resident Inspector (Charles.Peabody@nrc.gov)
Resident Inspector (Raja.Stroble@nrc.gov)
WC Administrative Assistant (Carey.Spoon@nrc.gov)
Branch Chief, DRP/B (Neil.OKeefe@nrc.gov)
Senior Project Engineer, DRP/B (David.Proulx@nrc.gov)
Project Engineer, DRP/B (Fabian.Thomas@nrc.gov)
Project Engineer, DRP/B (Steven.Janicki@nrc.gov) Public Affairs Officer (Victor.Dricks@nrc.gov
) Public Affairs Officer (Lara.Uselding@nrc.gov)
Project Manager (Fred.Lyon@nrc.gov) Branch Chief, DRS/TSB (Geoffrey.Miller@nrc.gov)
RITS Coordinator (Marisa.Herrera@nrc.gov
) ACES (R4Enforcement.Resource@nrc.gov)
Regional Counsel (Karla.Fuller@nrc.gov)
Technical Support Assistant (Loretta.Williams@nrc.gov)
Congressional Affairs Officer (Jenny.Weil@nrc.gov)
RIV Congressional Affairs Officer (Angel.Moreno@nrc.gov)
RIV/ETA: OEDO (Michael.Waters@nrc.gov)
NRR/DPR/PLPB Senior Project Manager (Brian.Benney@nrc.gov)
- 1 - Enclosure U.S. NUCLEAR REGULATORY COMMISSION REGION IV Docket: 05000 482 License: NPF-42 Report: 05000 482/20 14005 Licensee: Wolf Creek Nuclear Operating Corporation (WCNOC) Facility: Wolf Creek Generating Station Location: 1550 Oxen Lane NE Burlington, Kansas Dates: September 27 through December 31, 2014 Inspectors:
D. Dodson, Acting Senior Resident Inspector C. Peabody, Senior Resident Inspector R. Stroble, Resident Inspector G. Apger, Operations Engineer B. Correll, Reactor Inspector T. Hartman, Senior Resident Inspector, Callaway S. Hedger, Operations Engineer M. Kennard, Operations Engineer D. Proulx, Senior Project Engineer Approved By: Neil O'Keefe Chief, Project Branch B Division of Reactor Projects
- 2 - Enclosure
SUMMARY
IR 05000 482/20 14 0 05; 09/27/2014
-12/31/2014
- WOLF CREEK GENERATING STATION
- Integrated Resident and Regional Report; Licensed Operator Requalification Program
. The inspection activities described in this report were performed between September 27 and December 31, 2014, by the resident inspectors at Wolf Creek Generating Station and inspectors from the NRC's Region IV office. One finding of very low safety significance (Green) is documented in this report. The significance of inspection findings is indicated by their color (Green, White, Yellow, or Red), which is determined using Inspection Manual Chapter 0609, "Significance Determination Process." Their cross-cutting aspects are determined using Inspection Manual Chapter 0310, "Aspects within the Cross-Cutting Areas." Violations of NRC requirements are dispositioned in accordance with the NRC Enforcement Policy. 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.
The inspectors identified a Green finding for the inadequate conduct and evaluati o n of simulator performance testing in accordance with the standards of ANSI/ANS 3.5-2009 and ANSI/ANS 3.5
-1998, "Nuclear Power Plant Simulators for Use in Operator Training and Examination." Specifically, Wolf Creek Nuclear Operating Corporation (WCNOC) did not adequately identify that the simulator responses during 2008 through 2014 tests of Transient 3, "Simultaneous Closure of All Main Steam Isolation Valves," did not meet the acceptance criteria described in Section 4.1.4 of ANSI/ANS 3.5
-2009 (or the 1998 edition), which if left uncorrected, could have resulted in negative training of licensed operators and call into question Wolf Creek's ability to conduct valid licensing examinations with the simulator. WCNOC initiated condition reports 90179 and 90417 and simulator discrepanc y report A14-154. WCNOC also plans to conduct benchmarking at other sites to compare simulator responses during applicable testing, and is evaluating the need for additional procedure revisions or other corrective actions.
The performance deficiency is more than minor because it adversely impacted the human performance attribute of the mitigating systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Additionally, if left uncorrected, the performance deficiency could have become more significant in that not correcting noticeable differences between the simulator and the reference plant could cause negative training of licensed operators and call into question WCNOC's ability to conduct valid licensing examinations with the simulator. Utilizing Inspection Manual Chapter 0609, "Significance Determination Process," Attachment 4, Tables 1 and 2 worksheets, issued June 19, 2012, and flowchart b lock 14 of Appendix I, "Licensed Operator Requalification Significance Determination Process (SDP)," issue d December 6, 2011, the finding was determined to have very low safety significance (Green), because the deficiencies were associated with simulator testing, modifications, and maintenance, and there was no evidence that the plant-referenced simulator does not demonstrate the expected plant response or have uncorrected modeling and hardware deficiencies
. This finding has a cross-cutting aspect in the area of problem identification and resolution, Identification, because WCNOC personnel did not implement a corrective action program with a low threshold for identifying issues.
Specifically, this issue was first identified when the RETRAN
-3D code analysis was first used in 2008 transient testing, and additional tests performed in 2008, 2009, 2010, and 2012 were opportunities to identify the performance deficiency; however, the issue was not entered into the corrective action program, a noticeable difference was not evaluated, a training needs assessment was not performed, and the process used to conduct simulator transient testing, as described in Procedure Al 30C-006, was not updated to include all of the minimum acceptance criteria described in the ANSI/ANS 3.5 standard.
Hence, simulator issues expected to be identified during the testing process could potentially be missed by implementing the AI 30C
-006 procedure, which did not include all of the minimum acceptance criteria described in the ANSI standard [P.1]. (Section 1R11)
PLANT STATUS
Wolf Creek began the inspection period at 100 percent power. On November 14, 2014, operators reduced power to approximately 90 percent after the B condensate pump tripped on instantaneous overcurrent. Following repairs, operators returned the unit to 100 percent on November 24, 2014. The unit remained at or near 100 percent power for the remainder of the inspection period.
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity 1 R 01 Adverse Weather Protection (71111.01)
.1 Readiness for Seasonal Extreme Weather Conditions
a. Inspection Scope
On November 4, 2014
, the inspectors completed an inspection of the station's readiness for seasonal extreme weather conditions. The inspectors reviewed Wolf Creek Nuclear Operating Company's (WCNOC) adverse weather procedures for seasonal low temperatures and evaluated WCNOC's implementation of these procedures. The inspectors verified that prior to the onset of cold weather
, WCNOC had corrected weather-related equipment deficiencies identified during the previous winter.
The inspectors selected two risk-significant systems that were required to be protected from cold weather
- r adioactive waste storage tank reactor make
-up storage tank The inspectors reviewed WCNOC's procedures and design information to ensure the components would remain functional when challenged by adverse weather. The inspectors verified that operator actions described in WCNOC's procedures were adequate to maintain readiness of these systems. The inspectors walked down portions of these systems to verify the physical condition of the adverse weather protection features. These activities constitute one sample of readiness for seasonal adverse weather , a s defined in Inspection Procedure 71111.01.
b. Findings
No findings were identified.
R 04 Equipment Alignment (71111.04)
.1 Partial Walk
down
a. Inspection Scope
The inspectors performed partial system walk
-downs of the following risk
-significant systems: November 5, 2014, A control room air conditioning December 16, 2014, B safety injection December 17, 2014, B containment spray The inspectors reviewed WCNOC's procedures and system design information to determine the correct lineup for the systems. They visually verified that critical portions of the systems were correctly aligned for the existing plant configuration
. These activities constitute three partial system walk
-down sample s as defined i n Inspection Procedure 71111.04.
b. Findings
No findings were identified.
.2 Complete Walkdown
a. Inspection Scope
On October 16, 2014, the inspectors performed a complete system walk-down inspection of both trains of emergency diesel generator s. The inspectors reviewed WCNOC's procedures and system design information to determine the correct system lineup for the existing plant configuration. The inspectors also reviewed outstanding work orders, and other open items tracked by WCNOC's operations and engineering departments. The inspectors then visually verified that the system was correctly aligned for the existing plant configuration.
These activities constitute one complete system walk
-down sample , as defined in Inspection Procedure 71111.04.
b. Findings
No findings were identified.
1 R 05 Fire Protection (71111.05)
.1 Quarterly Inspection
a. Inspection Scope
The inspectors evaluated WCNOC's fire protection program for operational status and material condition. The inspectors focused their inspection on four plant areas important to safety:
October 28, 2014, auxiliary building area A
-1 , 1974 f oo t general area October 30, 2014, auxiliary building area A
-19 , exhaust fans and filter units October 30, 2014, auxiliary building area A
-16 , component cooling water pumps and heat exchangers December 5, 2014, essential service water pipe chase For each area, the inspectors evaluated the fire plan against defined hazards and defense-in-depth features in WCNOC's fire protection program. The inspectors evaluated control of transient combustibles and ignition sources, fire detection and suppression systems, manual firefighting equipment and capability, passive fire protection features, and compensatory measures for degraded conditions.
These activities constitute four quarterly inspection sample s , as defined in Inspection Procedure 71111.05.
b. Findings
No findings were identified.
1 R 06 Flood Protection Measures (71111.06)
a. Inspection Scope
The inspectors completed inspection s of the station's ability to mitigate flooding due to internal causes. After reviewing WCNOC's flooding analysis, the inspectors chose two plant areas containing risk
-significant structures, systems, and components (SSCs) that were susceptible to flooding:
October 27, 2014, train B residual heat removal and containment spray rooms December 5, 2014, essential service water pipe chase The inspectors reviewed plant design features and WCNOC procedures for coping with internal flooding. The inspectors walked down the selected areas to inspect the design features, including the material condition of seals, drains, and flood barriers. The inspectors evaluated whether operator actions credited for flood mitigation could be successfully accomplished.
These activities constitute completion of two flood protection measures sample s as defined in Inspection Procedure 71111.06.
b. Findings
No findings were identified.
R 11 Licensed Operator Requalification Program and Licensed Operator Performance (71111.11)
.1 Review of Licensed Operator Requalification
a. Inspection Scope
On November 12, 2014, the inspectors observed an evaluated simulator scenario performed by an operating crew. The inspectors assessed the performance of the operators and the evaluators' critique of their performance.
These activities constitute completion of one quarterly licensed operator requalification program sample , as defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
.2 Review of Licensed Operator Performance
a. Inspection Scope
On December 12, 2014
, the inspectors observed the performance of on
-shift licensed operators in the plant's main control room. The observations were completed during off-normal hours. The inspectors observed the operators' performance of the following activities:
dilution of the reactor coolant system for reactivity control briefing for changing of relief valves on the train B emergency diesel generator air compressor briefing for conducting D component cooling water pump vibration monitoring In addition, the inspectors assessed the operators' adherence to plant procedures, including the conduct of operations procedure and other operations department policies.
These activities constitute completion of one quarterly licensed operator performanc e sample , a s defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
.3 Biennial Review of Requalification Program
a. Inspection Scope
To assess the performance effectiveness of the licensed operator requalification program, the inspectors conducted personnel interviews, reviewed both the operating tests and written examinations, and observed ongoing operating test activities.
The inspectors interviewed six WCNOC individuals from the training staff to determine their understanding of the policies and practices for administering requalification examinations. The inspectors also reviewed operator performance on the written examinations and operating tests. These reviews included observations of portions of the operating tests by the inspectors. The operating tests observed included six job performance measures and two scenarios that were used in the current biennial requalification cycle. These observations allowed the inspectors to assess WCNOC's effectiveness in conducting the operating test to ensure operator mastery of the training program content. The inspectors also reviewed medical records of nine licensed operators for conformance to license conditions, and WCNOC's system for tracking qualifications and records of license reactivation for five operators.
The results of these examinations were reviewed to determine the effectiveness of WCNOC's appraisal s of operator performance and to determine if performance analys i s feedback was being incorporated into the requalification training program. The inspectors interviewed members of the training department and reviewed minutes of training review group meetings to assess the responsiveness of the licensed operator requalification program to incorporate the lessons learned from both plant and industry events. Examination results were also assessed to determine if they were consistent with the guidance contained in Supplement 1 of NUREG 1021, "Operator Licensing Examination Standards for Power Reactors", Revision 9, and Appendix I, "Licensed Operator Requalification Significance Determination Process (SDP)," of NRC Inspection Manual Chapter 0609, "Significance Determination Process," issued June 2, 2011.
In addition, the inspectors reviewed examination security measures, simulator fidelity, and existing logs of simulator deficiencies.
On November 14, 2014, WCNOC informed the lead inspector of the results of the written examinations and operating tests for the Licensed Operator Requalification Program. The inspectors compared these results to NRC Inspection Manual Chapter 0609 Appendix I values and determined that there were no findings based on these results; additionally, all of the individuals that failed the applicable portions of their examinations and/or operating tests were remediated, retested, and passed their retake examinations prior to returning to shift.
These activities constitute completion of one biennial requalification program sample, as defined in Inspection Procedure 71111.11.
b. Findings
1. Failure to Conduct and Evaluate Simulator Testing In Accordance With ANSI/ANS
3.5-2009 and ANSI/ANS 3.5-1998
Introduction.
The inspectors identified a Green finding for WCNOC inadequately conducting and evaluating simulator performance testing in accordance with the standards of ANSI/ANS 3.5-2009 and ANSI/ANS 3.5-1998, "Nuclear Power Plant Simulators for Use in Operator Training and Examination."
Specifically, WCNOC did not adequately identify that the simulator responses during 2008 through 2014 tests of Transient 3, "Simultaneous Closure of All Main Steam Isolation Valves," did not meet the acceptance criteria described in Section 4.1.4 of ANSI/ANS 3.5-2009 (or the 1998 edition), which if left uncorrected, could have resulted in negative training of licensed operators and call into question Wolf Creek's ability to conduct valid licensing examinations with the simulator.
Description.
In order to maintain an NRC approved simulation facility, licensees are required to conduct performance testing throughout the life of the simulator to ensure that it can be used to model control manipulations consistent with the actual plant.
An acceptable method for conducting this testing is by using industry standard ANSI/ANS 3.5. This industry standard has been endorsed by the NRC in Regulatory Guide 1.149, "Nuclear Power Plant Simulation Facilities for Use in Operator Training, License
Examinations, and Applicant Experience Requirements," Revision 4 (and Revision 3), as an acceptable method to complet e required simulator testing to meet the requirements of 10 CFR 55.46. WCNOC procedure AI 30C
-001, "Continued Assurance of Simulator Fidelity,"
Revision 15 , references ANSI/ANS 3.5-2009 as the standard for its simulator testing. Part of the required testing detailed in the ANSI/ANS 3.5 standard includes transient performance tests, which include simulator tests on 11 specific transients specified in Section B.3.2 of Appendix B of the ANSI/ANS 3.5 standard. Section B.1.2 of Appendix B of the ANSI/ANS 3.5 standard states that the acceptance criteria for these tests are documented in Section 4.1.4 of the ANSI/ANS 3.5 standard. This section states that simulator response during transient testing will meet the following acceptance criteria:
(1) "The simulator allows the use of applicable reference unit procedures;
- (2) Any observable change in simulated parameters corresponds in direction to the change expected from actual or best estimate response of the reference unit to the transient test;
- (3) The simulator shall not fail to cause an alarm or automatic action if the reference unit would have caused an alarm or automatic action under identical circumstances; and
- (4) The simulator shall not cause an alarm or automatic action if the reference unit would not cause an alarm or automatic action under identical circumstances.
" A failure to meet these acceptance criteria constitute s a difference in the dynamic response between the simulator and the reference unit that is distinguishable by an observer and confirmed by a subject matter expert. This is defined as a noticeable difference by the ANSI/ANS 3.5 standard. Noticeable differences are evaluated by performing a training needs assessment in accordance with Section 4.2.1.4 of the ANSI/ANS 3.5 standard. This assessment helps in determining the appropriate corrective action s, as well as in identifying potential negative effects the noticeable difference can have on licensed operator training.
Procedure AI 30C
-001 describes how WCNOC maintains and tests the simulator to meet the ANSI/ANS 3.5 standard. Section 6.4.2 of AI 30C-001 , s ub-item 4 states, in part, that transient testing acceptance criteria are contained in procedure AI 30C
-006 , "Simulator Transient Testing.
" Section 6.6.1 of AI 30C-006, Revision 11, states, in part, with respect to acceptance criteria, that "The test plots shall be reviewed by the LSI
-Simulator or his designee to ensure that the observable change in parameters correspond in direction to those expected from a best estimate for the simulated transient and do not violate the physical laws of nature." This is the only portion of the procedure that addresses the acceptance criteria, and it only addresses acceptance criteria (2)of the ANSI/ANS 3.5 standard
.
For a comparison of the simulator results during the testing, licensees use baseline data representing the reference unit, consistent with the preference of data sources stated in Section 5.1.1 of the ANSI/ANS 3.5 standard. In this case, WCNOC used the results from a RETRAN
-3D engineering software code analysis prepared in 2006 to specifically support ANSI/ANS transient testing.
During the 2014 performance of Transient 3, the simulator initiate d a reactor trip based on steam generator lo
-lo level signals between 3.4 and 3.85 seconds into the test. The RETRAN-3D code analysis for Transient 3 show ed a reactor trip based on high pressurizer pressure between 7 and 7.5 seconds into the test. In this case, the simulator caused an alarm and automatic action (reactor trip based on steam generator lo
-lo levels, showing with lit indication on reactor protection system channels A through D) that the reference unit did not initiate.
This test was not successful based on acceptance Criterion 4 of the ANSI/ANS 3.5 standard. In accordance with the ANSI/ANS 3.5 standard , this should have resulted in observation of a noticeable difference. However, an observation of a noticeable difference was not documented, and corrective action s were not evaluated using a training needs assessment.
WCNOC conducted Transient 3 on the simulator on April 10, 2014. The test was considered complete and satisfactory on September 10, 2014. On December 3, 2014, the NRC inspectors communicated to WCNOC that the test results did not meet the acceptance criteria stated in the ANSI/ANS 3.5 standard. On December 9, 2014, further discussion with WCN OC revealed that this issue had been identified when the RETRAN
-3D code analysis was first used in 2008 transient testing. With this information, NRC inspectors requested documentation showing that this noticeable difference was evaluated during this time period consistent with Section 4.2.1.4 of the ANSI/ANS 3.5 standard, which would include a training needs assessment. There was no documented evidence provided showing that this evaluation took place. WCNOC initiated Condition Reports 90179 and 90417 and simulator discrepancy report A14-154. WCNOC also plans to conduct benchmarking at other sites to compare simulator responses during applicable testing, and WCNOC is evaluating the need for additional procedure revisions or other corrective actions.
Analysis.
The failure to adequately conduct and evaluat e simulator performance testing in accordance with ANSI/ANS 3.5-2009 (and the 1998 edition), as referenced by site procedure AI 30C-001, Revision 15, and as endorsed by Regulatory Guide 1.149, Revisions 3 and 4 , was a performance deficiency. The performance deficiency is more than minor because it adversely affected the human performance attribute of the mitigating systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Additionally, if left uncorrected, the performance deficiency would have the potential to become more significant in that not correcting noticeable differences between the simulator and the reference plant could cause negative training of licensed operators and call into question WCNOC's ability to conduct valid licensing examinations with the simulator.
Utilizing Inspection Manual Chapter 0609, "Significance Determination Process," Attachment 4, Tables 1 and 2 worksheets, issued June 19, 012, and flowchart block 14 of Appendix I, "Licensed Operator Requalification Significance Determination Process (SDP)," issue d December 6, 2011, the finding was determined to have very low safety significance (Green)
, because the deficiencies were associated with simulator testing, modifications and maintenance
, and there was no evidence that the plant
-referenced simulator does not demonstrate expected plant response or have uncorrected modeling and hardware deficiencies.
This finding has a cross
-cutting aspect in the area of problem identification and resolution , Identification, because WCNOC personnel did not implement a corrective action program with a low threshold for identifying issues.
Specifically, this issue was first identified when the RETRAN
-3D code analysis was first used in 2008 transient testing, and additional tests performed in 2008, 2009, 2010, and 2012 were opportunities to identify the performance deficiency; however, the issue was not entered into the corrective action program, a noticeable difference was not evaluated, a training needs assessment was not performed, and the process used to conduct simulator transient testing, as described in Procedure Al 30C-006, was not updated to include all of the minimum acceptance criteria described in the ANSI/ANS 3.5 standard.
Hence, simulator issues expected to be identified during the testing process could potentially be missed by implementing the AI 30C
-006 procedure, which did not include all of the minimum acceptance criteria described in the ANSI standard [P.1].
Enforcement.
This finding does not involve enforcement action , because no violation of a regulatory requirement occurr ed. Because this finding does not involve a violation and is of very low safety significance, it is identified as FIN 05000482/2014 005-01 , "Failure to Conduct and Evaluate Simulator Testing In Accordance With ANSI/ANS 3.5-2009 and ANSI/ANS 3.5-1998." 1 R 12 Maintenance Effectiveness (71111.12)
a. Inspection Scope
On December 29, 2014, the inspectors reviewed an instance of degraded performance or condition of the non
-safety auxiliary feedwater pump. The inspectors reviewed the extent of condition of possible common cause SSC failures and evaluated the adequacy of WCNOC's corrective actions. The inspectors reviewed WCNOC's work practices to evaluate whether these may have played a role in the degradation of the SSCs. The inspectors assessed WCNOC's characterization of the degradation in accordance with 10 CFR 50.65 (the Maintenance Rule), and verified that WCNOC was appropriately tracking degraded performance and conditions in accordance with the Maintenance Rule. In addition, the inspectors reviewed WCNOC's biannual assessment of maintenance rule program implementation and ensured it was completed in accordance with 10 CFR 50.65.(a)(3). The inspectors reviewed the periodic evaluation to determine that the review took into account industry operating experience, to determine that WCNOC made appropriate adjustments to goals and performance criteria, and to determine that WCNOC met the objective of balancing the prevention of failures of SSCs through maintenance with minimizing system unavailability.
These activities constitute completion of two maintenance effectiveness sampl es , a s defined in Inspection Procedure 71111.12.
b. Findings
No findings were identified.
1 R 13 Maintenance Risk Assessments and Emergent Work Control (71111.13)
a. Inspection Scope
On October 6, 2014, the inspectors reviewed a weekly risk assessment performed by WCNOC prior to changes in plant configuration and the risk management actions taken by WCNOC in response to elevated risk.
The inspectors verified that this risk assessment was performed in a timely manner and in accordance with the requirements of 10 CFR 50.65 (the Maintenance Rule) and plant procedures. The inspectors reviewed the accuracy and completeness of WCNOC's risk assessment and verified that WCNOC implemented appropriate risk management actions based on the result s of the assessment.
The inspectors also observed portions of three emergent work activities that had the potential to cause an initiating event or to affect the functional capability of mitigating systems: October 6 through 8, 2014, replacement of current transformers for emergency diesel generator B and adjustment of emergency diesel generator B governor following erratic behavior November 5, 2014, control room air conditioning unit SGK04B maintenance November 15, 2014, condensate pump B motor failure The inspectors verified that WCNOC appropriately developed and followed a work plan for these activities. The inspectors verified that WCNOC took precautions to minimize the impact of the work activities on unaffected SSCs. These activities constitute completion of four maintenance risk assessments and emergent work control inspection sample s , as defined in Inspection Procedure 71111.13.
b. Findings
No findings were identified.
1 R 15 Operability Determinations and Functionality Assessments (71111.15)
a. Inspection Scope
The inspectors reviewed five operability determinations that WCNOC performed for degraded or nonconforming SSCs:
October 22, 2014, operability determination related to heavy machinery impact on essential service water manhole 1A sump discharge October 23, 2014 , operability determination related to emergency diesel generator A following an emergency diesel generator B failure December 18, 2014, operability determination related to control room ventilation isolation system following an unplanned system actuation December 19, 2014, engineering evaluation related to essential service water piping missile protection December 22, 2014, engineering evaluation related to reactor coolant system unidentified leakage monitoring capability following containment instrument tunnel sump pump issues The inspectors reviewed the timeliness and technical adequacy of WCNOC's evaluations. Where WCNOC determined a degraded SSC to be operable or functional , the inspectors verified that WCNOC's compensatory measures were appropriate to provide reasonable assurance of operability or functionality. The inspectors verified that WCNOC had considered the effect s of other degraded conditions on the operability or functionality of the degraded SSC s. These activities constitute completion of five operability and functionality review sample s , as defined in Inspection Procedure 71111.15.
b. Findings
No findings were identified.
1 R 18 Plant Modifications (71111.18)
a. Inspection Scope
On October 10, 2014, the inspectors reviewed one temporary modification to emergency diesel generator B that bypassed the selector switch for the rectifier banks for emergency diesel generator B and removed rectifier bank #2 from the circu it to support emergency diesel generator B operability following failure of the rectif ier and subsequent fire in the exciter cabinet. This event is further discussed in Section 4OA3.1.
The inspectors verified that WCNOC installed this temporary modification in accordance with technically adequate design documents. The inspectors verified that this modification did not adversely impact the operability or availability of affected SSCs. The inspectors reviewed design documentation and plant procedures affected by the modification to verify WCNOC maintained configuration control.
Th is activit y constitute s completion of one temporary modification sample, as defined in Inspection Procedure 71111.18
b. Findings
No findings were identified.
R 19 Post-Maintenance Testing (71111.19)
a. Inspection Scope
The inspectors reviewed seven post-maintenance testing activities that affected risk
-significant SSCs:
October 8, 2014, emergency diesel generator B following current transformer repairs October 28, 2014, control room air conditioning unit water regulating valve following maintenance November 4, 2014, control room air conditioning unit SGK04B following planned maintenance November 24, 2014, condensate pump B inservice test and leak check following corrective maintenance December 4, 2014, bus tie breaker NG00216 to safety bus es NG02/NG04 December 15, 2014, component cooling water pump D following planned maintenance December 16, 2014, safety injection pump B following planned maintenance The inspectors reviewed licensing and design
-basis documents for the SSCs and the maintenance and post-maintenance test procedures.
The inspectors observed the performance of the post
-maintenance tests to verify that WCNOC performed the tests in accordance with approved procedures, satisfied the established acceptance criteria, and restored the operability or functionality of the affected SSCs.
These activities constitute completion of seven post-maintenance testing inspection sample s , as defined in Inspection Procedure 71111.19.
b. Findings
No findings were identified.
1 R 22 Surveillance Testing (71111.22)
a. Inspection Scope
The inspectors observed five risk-significant surveillance tests and reviewed test results to verify that these tests adequately demonstrated that the SSCs were capable of performing their safety functions:
In-service test s: October 23, 2014, emergency diesel generator A one hour test run and rectifier bank thermography December 3, 2014, turbine
-driven auxiliary feedwater quarterly testing Containment isolation valve surveillance tests: December 17, 2014, containment spray B valve EMHV012 Other surveillance tests:
October 20, 2014, pressure testing of the A containment coolers November 3, 2014, pressure testing of the B containment coolers The inspectors verified that these test s met technical specification requirements, that WCNOC performed the tests in accordance with its procedures, and that the results of the test s satisfied appropriate acceptance criteria.
These activities constitute completion of five surveillance testing inspection sample s , a s defined in Inspection Procedure 71111.22.
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1 EP 6 Drill Evaluation (71114.06)
.1 Training Evolution Observation
a. Inspection Scope
On December 3, 2014, the inspectors observed simulator
-based licensed operator requalification training that included implementation of WCNOC's emergency plan. The inspectors verified that WCNOC's emergency classifications and off
-site notifications were appropriate and timely. The inspectors verified that any emergency preparedness weaknesses were appropriately identified by the evaluators and entered into the corrective action program for resolution.
These activities constitute completion of one training observation sample, as defined in Inspection Procedure 71114.06.
b. Findings
No findings were identified.
OTHER ACTIVITIES
Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity, Emergency Preparedness, Public Radiation Safety, Occupational Radiation Safety, and Security OA 1 Performance Indicator Verification (71151)
.1 Safety System
Functional Failures (MS05)
a. Inspection Scope
For the period of October 1, 2013
, through September 30, 2014
, the inspectors reviewed licensee event reports (LERs), maintenance rule evaluations, and other records that could indicate whether safety system functional failures had occurred. The inspectors used definitions and guidance contained in Nuclear Energy Institute Document 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 7, and NUREG
-1022, "Event Reporting Guidelines: 10 CFR 50.72 and 50.73," Revision 3, to determine the accuracy of the data reported.
These activities constitute verification of the safety system functional failures performance indicator, as defined in Inspection Procedure 71151.
b. Findings
No findings were identified.
.2 Mitigating Systems Performance Index
- Heat Removal System s (MS08)
a. Inspection Scope
The inspectors reviewed WCNOC's mitigating system performance index data for the period of October 1, 2013
, through September 30, 2014, to verify the accuracy and completeness of the reported data. The inspectors used definitions and guidance contained in Nuclear Energy Institute Document 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 7, to determine the accuracy of the reported data.
These activities constitute verification of the mitigating system performance index for heat removal systems, as defined in Inspection Procedure 71151.
b. Findings
No findings were identified.
.3 Mitigating Systems Performance Index
- Residual Heat Removal System s (MS09)
a. Inspection Scope
The inspectors reviewed WCNOC's mitigating system performance index data for the period of October 1, 2013
, through September 30, 2014, to verify the accuracy and completeness of the reported data. The inspectors used definitions and guidance contained in Nuclear Energy Institute Document 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 7, to determine the accuracy of the reported data. These activities constitute verification of the mitigating system performance index for residual heat removal systems, as defined in Inspection Procedure 71151.
b. Findings
No findings were identified.
4OA 2 Problem Identification and Resolution (71152)
.1 Routine Review
a. Inspection Scope
Throughout the inspection period, the inspectors performed daily reviews of items entered into WCNOC's corrective action program and periodically attended WCNOC's condition report screening meetings. The inspectors verified that WCNOC personnel were identifying problems at an appropriate threshold and entering these problems into the corrective action program for resolution. The inspectors verified that WCNOC developed and implemented corrective actions commensurate with the significance of the problems identified.
The inspectors also reviewed WCNOC's problem identification and resolution activities during the performance of the other inspection activities documented in this report.
b. Findings
No findings were identified.
.2 Semiannual Trend Review
a. Inspection Scope
To verify that WCNOC was taking corrective actions to address identified adverse trends that might indicate the existence of a more significant safety issue, the inspectors reviewed corrective action program documentation associated with the following licensee-identified trends:
high backlogs in the design implementation and configuration control process area corrective action program health i ndex These activities constitute completion of one semiannual trend review sample, as defined in Inspection Procedure 71152. b. Observations and Assessments The inspectors' review of the trends identified above produced a few observations and assessments.
The inspectors noted a recent apparent increase in the number of equipment reliability issues affecting important equipment that had significant impacts to the station.
There were five significant equipment issues that occurred between September 2014 and December 2014.
On September 3, 2014, the containment instrument tunnel sump level transmitter failed high and was not able to be reset.
This instrument is required for monitoring reactor coolant system leakage, and this failure placed the plant in a 30-day shutdown action statement.
The licensee ultimately opted to request and was granted an exigent Technical Specification amendment to rely on an alternative monitoring method, rather than shutting down the plant, because the system did not include a redundant level transmitter.
Additionally, the instrument is located in a part of the containment that was inaccessible due to high radiation levels, which prevented repairs.
On October 6, 2014, during a 24
-hour surveillance run of emergency diesel generator B, the generator tripped unexpectedly, and local operators reported a fire in the exciter cabinet shortly thereafter.
This resulted in an Alert declaration.
The initial assessment determined that power rectifier diodes that were original equipment had failed.
This resulted in a significant disruption to station activities to repair fire damage and to retest the system.
Ultimately, a request for enforcement discretion was needed to avoid a plant shutdown.
On November 14, 2014, the B condensate pump tripped on instantaneous overcurrent, challenging operators to rapidly reduce power due to the loss of available condensate flow.
The motor was found to have an internal short and had to be rebuilt, causing the plant to be operated at 90 percent power for 10 days.
On December 6, 2014, the station experienced an invalid control room ventilation isolation signal, and during the ensuing system response, four train A dampers did not reposition as expected.
This resulted in an unplanned Technical Specification entry and significant troubleshooting, but the licensee did not identify clear any cause.
On December 16, 2014, the A containment instrument tunnel sump pump failed to stop when sump level was pumped down to the low level setpoint.
The automatic operation of these sump pumps was approved to temporarily be used to meet the Technical Specification
-required reactor coolant system leakage monitoring capability in Amendment No. 211.
The loss of automatic sump pump operation reliability caused operators to declare the leakage monitoring system inoperable and caused considerable disruption of station activities while the licensee conducted troubleshooting and worked to restore a reliable method of leakage monitoring in order to avoid shutting the plant down.
WCNOC personnel documented in the corrective action program Condition Report 90828 to evaluate these issues as a potential trend and to identify any common causes.
The licensee had made a significant effort to resolve longstanding equipment reliability issues from 2012 through early 2014.
This effort included making major changes to the preventive maintenance program that included verification of vendor recommendations and incorporating industry best practices.
The inspectors noted that plant equipment reliability had been noticeably improved until this quarter.
The equipment challenges identified above challenged operators and the site.
While the Preventive Maintenance Optimization Program has begun implementation and the licensee risk
-informed the initial work scheduling, the inspectors noted that at least the first fouyr examples above were not specifically addressed by the preventive maintenance improvements.
The inspectors noted that in July 2013
, an external assessment of station performance noted an unusually high number of open design changes. WCNOC took corrective actions to address the apparent cause of this issue. Specifically, WCNOC develop ed a configuration change management health plan and developed a comprehensive backlog reduction strategy.
While these measures initially proved effective in reducing the backlog of open design changes
, the inspectors noted that the licensee recently revised their original goals for completing the planned backlog reduction.
WCNOC's original goal was to reduce the total number of design change and configuration change packages to 200 by the end of the fourth quarter of 2014 , and to reduce the total to 100 by June 2015. The revised goal is to reduce the total number of design change and configuration change packages to 350 by the end of the fourth quarter of 2014, retaining the original goal of 100 by June 2015. WCNOC attributed this change to shifting work to the more complex packages in the backlog. The inspectors noted that the shift in priorities appeared appropriate
- however, retaining the original goal of reducing the backlog down to 100 by June 2015 would be challenging given the available time and increasing complexity of the work
.
c. Findings
No findings were identified.
4OA 3 Follow-up of Events and Notices of Enforcement Discretion (71153)
.1 Emergency Diesel Generator B Exciter Cabinet Fire
a. Inspection Scope
On October 6, 2014, during a 24
-hour surveillance run of emergency diesel generator B, the generator tripped unexpectedly, and local operators reported a fire in the exciter cabine t shortly thereafter. The licensee declared a n Alert and dispatched the fire brigade. Resident inspectors respo nded to the control room to observe operator performance and assess plant conditions.
On October 20, 2014, inspectors performed a n inspection to further understand the events leading up to and following a fire in the emergency diesel generator B panel, to assess the cause, and to evaluate the potential for a common cause failure in the redundant part of the exciter circuit in emergency diesel generator B or the redundant train. The ins pectors discussed the process used by WCNOC to determine that the most likely cause of the fire was failure of two diodes in the number 2 power rectifier bridge circuit, which caused the power potential transformer to exceed its design current.
The inspectors reviewed the extent of the damage and the details of the repairs made prior to declaring the equipment operable, including the appropriateness of the post
-maintenance testing.
Since the exciter circuit contained a redundant rectifier bridge, WCNOC elected to install a temporary modification to lift leads and isolate the failed rectifier bank and place the redundant bridge in service
. This modification was separately inspected, as discussed in Section 1R18.
The inspectors reviewed condition reports, temporary modifications, troubleshooting activities, conducted interviews with engineering and operations personnel, and performed a visual inspection of the redundant train emergency diesel generator panel. The team reviewed the root cause analysis activities performed while onsite, and discussed the status with the responsible manager and select team members.
b. Findings and Observations
No findings were identified
. However, the inspectors identified two concerns:
On October 9, 2014, as part of a request for a Notice of Enforcement Discretion, WCNOC committed to not use the power amplifier circuit that had been in service during the event (power amplifier number 2) until it ha d been fully tested. The inspectors noted that there were no physical or administrative controls in place to prevent selecting this power amplifier. WCNOC addressed this issue under Condition Report 89146 and expanded the clearance order used for the number 2 rectifier bank to include the number 2 power amplifier circuit selector switch.
WCNOC preliminarily determined that the cause of the fire was the failed diodes in the power rectifier and did not remove the components immediately following the event. The inspectors questioned the decision to wait to remove the failed diodes
, because WCNOC would be unable to determine the actual cause of the failure until these components were removed and analyzed. As a result, WCNOC re-evaluated its corrective actions and removed the failed rectifier bridge for further analysis in December 2014.
WCNOC documented this concern under Condition Report 89138.
.2 (Open) Notice of Enforcement Discretion (NOED) 14
02 for Emergency Diesel Generator B Exciter Cabinet Fire
Introduction.
An unresolved item (URI)is being opened to assess whether the cause for the request for enforcement discretion associated with the fire in the exciter circuit of emergency diesel generator B on October 6, 2014, involved a violation of NRC requirements
.
Description.
On October 6, 2014, at 1:26 p.m., emergency diesel generator B was declared inoperable when it tripped during a 24
-hour surveillance test and operators identified a fire in an associated exciter cabinet. An Alert was declared and operators entered Technical Specification 3.8.1, "AC Sources - Operating," Required Action B.4.1, which required emergency diesel generator B be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Actions in response to the fire were completed, the fire was quickly suppressed, and WCNOC exited the Alert.
Following the completion of repairs, WCNOC identified that postmaintenance testing required to demonstrate system operability included completing a 24
-hour run. Since the postmaintenance testing and subsequent system restoration was expected to exceed the time remaining in the 72
-hour action statement, WCNOC requested that the NRC exercise discretion to not enforce compliance with the actions required in Wolf Creek Generating Station Technical Specification 3.8.1, Required Action B.4.1, and approve an additional 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to restore the system. NOED NO. 14 02, documents this request and the NRC's approval. Following postmaintenance testing, emergency diesel generator B was restored to operable status at 5:17 p.m. on October 9, 2014.
WCNOC concluded that the most likely cause of the event was the failure of the power current transformers' power rectifier bridge. WCNOC postulated that when the bridge failed, power from the power current transformers to the generator field was lost. As a result, the voltage regulator attempted to maintain the field current using only the power potential transformer. Since the power potential transformer is not rated to sustain full field current, the transformer was overloaded, which caused it to overheat and catch fire. Troubleshooting also indicated that the emergency diesel generator B tripped on phase differential current for the same reasons.
WCNOC removed the failed rectifier bridge for further analysis in December 2014; at the end of the inspection period, WCNOC personnel were awaiting additional failure analyses of the failed rectified bridge to determine the specific direct causes of the fire and unplanned emergency diesel generator B inoperability.
The root cause is being evaluated by Condition Report 88665.
When an NOED is issued, Inspection Manual Chapter 04 10, "Notice of Enforcement Discretion," requires that a URI will be opened to assess wh ether the cause(s) of the events leading up to the request for the Notice of Enforcement Discretion involved violation s of NRC requirements. This issue will be tracked as a URI in order to review and evaluate WCNOC's additional rectifier bridge failure analyses, root cause analysis , and other supporting documentation to determine if a violation exists
-0 2 , "Notice of Enforcement Discretion 14 02 for Emergency Diesel Generator B Exciter Cabinet Fire
." These activities constitute completion of two event follow
-up sample s, as defined in Inspection Procedure 71153. 4OA 5 Other Activities (Closed) T e m p o r a r y I n s tr u c t i on 2 5 1 5/190 - I ns p e c t i on o f t he Propos e d I n terim A c t i o n s Assoc iated w i t h N e a r-T e r m T a s k F o rce R ec o mm e n d a t i on 2.1 F l o o d i ng H a zard E v a l u a t i o n s
a. Inspection Scope
I ns p e c t o r s v er i f i ed t h a t WCNOC's inte r i m a c t i o n s w i l l p e r f o r m t h ei r inten d ed f u n c t i on for f l o o d i n g m i t i gati o n. T he i ns pect o r s i n d e p e n d e n t l y veri f i ed t h a t WCNOC's propos e d inte r im acti o ns w o ul d p e r f o r m t h ei r intend e d f uncti o n f o r f l o o d ing m i t i g a ti o n.
Vi su a l i ns pecti o n o f t he f l o o d p r o tecti o n f e a ture was pe r f o r m ed i f t he f l o o d pro t e c t ion f e a t u r e was r e l e v a n t. E x ternal v i su a l i ns pecti o n f or i n dicati ons o f d egrad a t ion t h a t w o uld pre v e n t i t s c r e di t ed f u n ct i on fr om b eing p e r f o r m ed was pe r f o rm e d.
R e a so n a ble simu lati o n, i f a p p li ca bl e t o t he s i t e F l o o d p rote c t i on f e a t u r e f u n c t i o n a li t y was de t er m i n ed us ing e i t h e r v i su a l o bser vati on or by r e v i e w of o t h e r d o c u m e n t s. T he i ns pect o r s v er i f i ed t h a t i ssu e s i d e nt i f i ed w e r e en t e r ed into WCNOC's c o rr e c t i v e ac t i on pr o g r a m.
b. Findings
No findings were identified.
4OA 6 Meetings, Including Exit
Exit Meeting Summary
On October 9, 2014, the inspectors debriefed the results of the licensed operator requalification program inspection to Mr. C. Reasoner, Site Vice President, and other members of the WCNOC staff. On December 16, 2014, the inspectors telephonically presented the results of the licensed operator requalification program inspection to Mr. S. Smith, Plant Manager, and other members of the WCNOC staff. WCNOC acknowledged the issues presented. WCNOC confirmed that any proprietary information reviewed by the inspectors had been returned or destroyed.
On January 8, 2014, the inspectors presented the resident inspection results to Mr. A. Heflin, Chief Executive Officer, and other members of the WCNOC staff. WCNOC acknowledged the issues presented. WCNOC confirmed that any proprietary information reviewed by the inspectors had been returned or destroyed.
SUPPLEMENTAL INFORMATION
==KEY POINTS
OF CONTACT==
Licensee Personnel
- T. Baban, Manager, Systems Engineering
- P. Black, Human Resources
- T. Branam, Design Engineer Electrical
- A. Broyles, Manager, Information Services
- T. Damashek, Simulator Fidelity Coordinator
- P. Deblonk, Superintendent , Instrumentation and Control
- J. Edwards, Manager, Operations
- D. Erbe, Manager, Security
- R. Flannigan, Manager, Nuclear Engineering
- J. Fritton, Owner's Representative
- A. Heflin, President and Chief Executive Officer
- R. Hobby, Licensing
- J. Knapp, Superintendent, Operations Training
- S. Koenig, Manager, Regulatory Affairs
- M. Legresley, System Engineer
- D. Mand, Manager, Design Engineering
- N. Mingle, System Engineer
- W. Muilenburg, Supervisor, Licensing
- J. Petty, System Engineer
- E. Ray, Manager, Training
- C. Reasoner, Site Vice President
- B. Ryan, Licensed Operator Supervising Instructor
- M. Skyles, Manager, Health Physics
- S. Smith, Plant Manager
- J. Steinert, Work Week Manager
- D. Sullivan, Manager, Supply Chain Services
- B. Vickery, Manager, Financial Services
- S. Wideman, Licensing
- J. Yunk, Manager, Corrective Actions
NRC Personnel
- J. Zimmerman, Branch Chief Electrical Engineering
- J. Robles, Reactor Systems Engineer
LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Opened
-02 URI Notice of Enforcement Discretion
14-4-02 for Emergency Diesel Generator
B Exciter Cabinet Fire (Section 4OA3
.2)
Opened and Closed
0500048 2/201 4005-01 FIN Failure to Conduct and Evaluate Simulator Testing In Accordance
with ANSI/ANS
3.5-2009 and ANSI/ANS 3.5-1998 (Section 1R11
.3) Closed NRC TI 2515/190
TI I ns p e c t i on o f t he Propos e d I n terim A c t i o n s Assoc iated w i t h N e a r-T e r m T a s k F o rce R ec o mm e n d a t ion 2.1 F l o o d i ng H a zard E v a l u a t i o n s (Section 4OA5)