IR 05000277/2017001
| ML17125A081 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 05/05/2017 |
| From: | Daniel Schroeder Reactor Projects Region 1 Branch 4 |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Barber G | |
| References | |
| IR 2017001 | |
| Download: ML17125A081 (36) | |
Text
May 5, 2017
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION - INTEGRATED INSPECTION REPORT 05000277/2017001 AND 05000278/2017001
Dear Mr. Hanson:
On March 31, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Peach Bottom Atomic Power Station (PB), Units 2 and 3. On April 21, 2017, the NRC inspectors discussed the results of this inspection with Mr. Pat Navin, Peach Bottom Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
The NRC inspectors did not identify any finding or violation of more than minor significance.
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and the NRCs Public Document Room in accordance with Title 10 Code of Federal Regulations (CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-56 Enclosure:
Inspection Report 05000277/2017001 and 05000278/2017001 w/Attachment:
Supplementary Information cc w/encl: Distribution via ListServ
SUMMARY
Inspection Report 05000277/2017001 and 05000278/2017001; 01/01/2017 - 03/31/2017;
Peach Bottom Atomic Power Station (PB), Units 2 and 3; Integrated Inspection Report.
This report covered a three-month period of inspection by resident inspectors and announced baseline inspections performed by regional inspectors. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649,
Reactor Oversight Process, Revision 6.
Cornerstone: Initiating Events, Mitigating Systems, and Barrier Integrity
No NRC-identified or self-revealing findings were identified during this inspection.
Other Findings
None.
REPORT DETAILS
Summary of Plant Status
Unit 2 began the inspection period at 100 percent rated thermal power (RTP). On January 17, 2017, Unit 2 experienced an emergent down power to 40 percent RTP after the 2A recirculation pump tripped. The recirculation pump speed drive system was repaired and the 2A recirculation pump was returned to service and the operators achieved 100 percent RTP on January 19, 2017. On January 23, 2017, operators downpowered to 75 percent RTP to address an indication issue with the turbine stop valves in the digital electrohydraulic control system. A loose connection was repaired and the unit was returned to full power operation the following day. On February 14, 2017, operators downpowered the unit to 80 percent RTP and removed the 2C feedwater pump from service due to flow oscillations. The feedwater pump linkage was repaired and the unit was returned to full power on February 16, 2017. The unit remained at 100 percent RTP except for brief periods to support planned testing and control rod pattern adjustments.
Unit 3 began the inspection period at 100 percent power. Unit 3 remained at 100 percent RTP until the end of the inspection period, except for brief periods to support planned testing and control rod pattern adjustments.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
Readiness for Impending Adverse Weather Conditions
a. Inspection Scope
The inspectors reviewed PBs preparation and response to a winter storm on February 8 and 9, 2017. The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR), technical specifications (TSs), control room logs, and the corrective action program (CAP) to determine what temperatures or other seasonal weather could challenge these systems, and to ensure PB personnel had adequately prepared for these challenges. The inspectors reviewed station procedures, including PBs seasonal weather preparation procedure and applicable operating procedures. The inspectors performed walkdowns of the selected systems to ensure station personnel identified issues that could challenge the operability of the systems during cold and blizzard weather conditions. Documents reviewed for each section of this inspection report are listed in the Attachment.
b. Findings
No findings were identified.
1R04 Equipment Alignment
Partial System Walkdowns (71111.04Q - 4 samples)
a. Inspection Scope
The inspectors performed partial walkdowns of the following systems:
- Unit 3 reactor core isolation cooling (RCIC) during a high-pressure coolant injection (HPCI) system outage window (SOW) on January 25, 2017
- Unit 3 B core spray (CS) loop with C residual heat removal (RHR) train out-of-service (OOS) on March 9, 2017
- Unit 2 and Unit 3 E-2 emergency diesel generator (EDG) during E-3 EDG overhaul on March 30, 2017 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 UFSAR, TSs, work orders (WOs), issue reports (IRs), and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted the systems performance of its 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 Exelon staff had properly identified equipment issues and entered them into the CAP for resolution with the appropriate significance characterization.
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 Exelon 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 OOS, degraded or inoperable fire protection equipment, as applicable, in accordance with procedures.
- Unit 2 A/C CS, 916 elevation on January 26, 2017
- Unit 2 reactor building closed-cooling water (RBCCW), 116 elevation on January 27, 2017
- Unit 3 RB general area, 165 elevation on February 28, 2017
- Unit 3 RB, north control rod drive equipment and west corridor, 135 elevation on March 2, 2017
- Unit 2 turbine building, turbine area, 165 elevation on March 2, 2017
1R06 Flood Protection Measures
Annual Review of Cables Located in Underground Bunkers/Manholes
a. Inspection Scope
The inspectors conducted an inspection of underground bunkers/manholes subject to flooding that contain cables whose failure could affect risk-significant equipment during the week of January 19, 2017. The inspectors performed walkdowns of risk-significant manhole 17 and 18, which contained E-1, E-2, E-3, and E-4 EDG cables, to verify that the cables were not submerged in water, that cables and/or splices appeared intact, and to observe the condition of cable support structures. When applicable, the inspectors verified proper sump pump operation and verified level alarm circuits were set in accordance with station procedures and calculations to ensure that the cables will not be submerged. The inspectors also ensured that drainage was provided and functioning properly in areas where dewatering devices were not installed. For those cables found submerged in water, the inspectors verified that PB had conducted an operability evaluation for the cables and were implementing appropriate corrective actions (CAs).
b. Findings
No findings were identified.
1R07 Heat Sink Performance
a. Inspection Scope
The inspectors reviewed the Unit 3 A fuel pool heat exchanger (HX) replacement and testing on February 23, 2017. The inspectors reviewed the design basis for the component and verified PBs commitments to NRC Generic Letter 89-13, Service Water System Requirements Affecting Safety-Related Equipment. The inspectors observed actual performance tests for the HXs and/or reviewed the results of previous inspections of the fuel pool cooling HXs. The inspectors discussed the results of the most recent inspection with engineering staff and reviewed pictures of the as-found and as-left conditions. The inspectors verified that PBAPS initiated appropriate CAs for identified deficiencies. The inspectors also verified that the number of tubes plugged within the HX did not exceed the maximum amount allowed.
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification Program and Licensed Operator Performance
.1 Quarterly Review of Licensed Operator Requalification Testing and Training (1 sample)
a. Inspection Scope
The inspectors observed licensed operator simulator training scenarios on January 25, 2017, which included mitigating the effects of the loss of RBCCW system and the loss of primary containment. 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 classifications made by the shift manager and the TS action statements entered by the shift technical advisor. 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
(1 sample)
a. Inspection Scope
The inspectors observed and reviewed the licensed operator performance from the main control room during the 2A recirculation trip and recovery actions on January 18, 2017.
The inspectors observed use of and compliance with procedures, crew communications, interpretation, diagnosis, and understanding of plant alarms, use of human error prevention techniques, documentation of activities, and management oversight of the evolution to verify that the crew was following procedures and plant expectations for conduct of operations.
The inspectors observed some control room briefings and power changes. Additionally, the inspectors observed power changes to verify that procedure use, crew communications, and coordination of activities between work groups similarly met established expectations and standards.
b. Findings
No findings were identified.
.3 Licensed Operator Requalification
a. Inspection Scope
The following inspection activities were performed using NUREG-1021, "Operator Licensing Examination Standards for Power Reactors," Revision 10, and Inspection Procedure (IP) Attachment 71111.11, Licensed Operator Requalification Program.
Examination Results On December 29, 2016, the results of the annual operating tests were reviewed in-office to determine if pass/fail rates were consistent with the guidance of NUREG-1021, "Operator Licensing Examination Standards for Power Reactors," Revision 10, and Inspection Manual Chapter 0609, Appendix I, Operator Requalification Human Performance Significance Determination Process (SDP). The review verified that the failure rate (individual or crew) did not exceed 20 percent.
- The overall individual operator failure rate was 0 percent
- The overall crew failure rate was 0 percent Written Examination Quality The inspectors reviewed a sample of biennial written examinations administered during the 2017 examination cycle for qualitative and quantitative attributes as specified in Appendix B of Attachment 71111.11B, Licensed Operator Requalification.
Operating Test Quality The inspectors reviewed the operating tests (scenarios and job performance measures (JPMs)) associated with the on-site examination week. The exam materials were reviewed for qualitative and quantitative attributes as specified in Appendix C of
===71111.11B, Licensed Operator Requalification Program.
Licensee Administration of Operating Tests The dynamic simulator exams and JPMs administered during the week of February 27, 2017, were observed. These observations included facility evaluations of crew and individual operator performance during the dynamic simulator exams and individual performance of JPMs.
Examination Security The inspectors assessed the facility staffs handling of exam material. The inspectors also checked JPMs, scenarios, and written examinations for excessive overlap of test items from week to week.
Conformance with Operator License Conditions License reactivation and license proficiency records were reviewed to ensure that Title 10 of the Code of Federal Regulations (10 CFR) 55.53 license conditions and applicable program requirements were met.
The inspectors also reviewed a sample of records for requalification training attendance, and a sample of medical examinations for compliance with license conditions and NRC regulations.
Simulator Performance Simulator performance and fidelity was reviewed for conformance to the reference plant control room. A sample of simulator deficiency reports was also reviewed to ensure facility staff addressed identified modeling problems. Simulator test documentation was also reviewed.
Problem Identification and Resolution A review was conducted of recent operating history documentation found in inspection reports, Exelons CAP, and the most recent NRC plant issues matrix. The inspectors also reviewed specific events from Exelons CAP which indicated possible training deficiencies, to verify that they had been appropriately addressed. The NRC resident inspectors were also consulted for insights regarding licensed operators 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 (SSCs) performance and reliability. The inspectors reviewed system health reports, CAP documents, maintenance WOs, and maintenance rule (MR) basis documents to ensure that Exelon was identifying and properly evaluating performance problems within the scope of the MR. For each sample selected, the inspectors verified that the SSC was properly scoped into the MR in accordance with 10 CFR 50.65 and verified that the (a)(2)performance criteria established by the Exelon staff was reasonable. As applicable, for SSCs classified as (a)(1), the inspectors assessed the adequacy of goals and CAs to return these SSCs to (a)(2) status. Additionally, the inspectors ensured that Exelon staff was identifying and addressing common cause failures that occurred within and across MR system boundaries.
- Unit 2 and Unit 3 non-safety related cranes on March 2, 2017
- Unit 2 and Unit 3 area radiation monitors on March 28, 2017
b. Findings
No findings were identified.
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 Exelon 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 Exelon personnel performed risk assessments as required by 10 CFR 50.65(a)(4) and that the assessments were accurate and complete. When Exelon 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, when applicable, to verify risk analysis assumptions were valid and applicable requirements were met.
- Elevated risk for the station blackout line, the #2 startup feed bus and the diesel driven fire pump which were all OOS on January 3, 2017
- Units 2 and 3 planned maintenance on emergency cooling tower valves on March 13, 2017
b. Findings
No findings were identified.
1R15 Operability Determinations and Functionality Assessments
a. Inspection Scope
The inspectors reviewed operability determinations (ODs) for the following degraded or non-conforming conditions based on the risk significance of the associated components and systems:
- Unit 2 and Unit 3 EDGs tornado missile hazard vulnerability on January 10, 2017
- Unit 2 and Unit 3 E-3 EDG temperature bearing high on February 9, 2017
- Unit 2 C CS elevated motor vibrations on March 28, 2017 The inspectors evaluated the technical adequacy of the ODs 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 TSs and UFSAR to Exelons evaluations to determine whether the components or systems were operable.
The inspectors confirmed, where appropriate, compliance with bounding limitations associated with the evaluations, including compliance with in-service testing requirements. Where compensatory measures were required to maintain operability, such as in the case of operator workarounds, the inspectors determined whether the measures in place would function as intended and were properly controlled by Exelon.
b. Findings
No findings were identified.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors reviewed the post-maintenance tests (PMTs) for the maintenance activities listed below to verify that procedures and test activities 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 test results were properly reviewed and accepted and problems were appropriately documented. The inspectors also walked down the affected job site, observed the pre-job brief and post-job critique where possible, confirmed work site cleanliness was maintained, and witnessed the test or reviewed test data to verify quality control hold points were performed and checked, and that results adequately demonstrated restoration of the affected safety functions.
- Unit 3 RCIC torus suction valve relay replacement on January 13, 2017
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors observed performance of surveillance test (STs) and/or reviewed test data of selected risk-significant SSCs to assess whether test results satisfied TSs, the UFSAR, and Exelon 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 STs:
- Unit 2 automatic depressurization system logic system functional test (LSFT) on January 11, 2017
- Unit 2 and Unit 3 E-4 EDG emergency core cooling system start on January 27, 2017
- Unit 3 HPSW/emergency service water (ESW) room sump pump functional and capacity test on February 17, 2017
- Unit 2 main steam isolation valve closure SCRAM response test on February 22, 2017
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP2 Alert and Notification System Evaluation
a. Inspection Scope
On March 16, 2017, the inspectors interviewed the Exelon siren program owner and conducted a review of the alert and notification system (ANS) to assess the maintenance and testing programs. The inspectors reviewed the associated ANS procedures and the Federal Emergency Management Agency approved ANS design report to ensure compliance with design report commitments for system maintenance and testing. The inspection was conducted in accordance with NRC IP 71114, Attachment 2. Title 10 of the CFR 50.47(b)(5) and the related requirements of 10 CFR Part 50, Appendix E, were used as reference criteria.
b. Findings
No findings were identified.
1EP3 Emergency Response Organization Staffing and Augmentation System (71114.03 -
1 sample)
a. Inspection Scope
The inspectors conducted a review of the PB Emergency Response Organization (ERO)augmentation staffing requirements and the process for notifying and augmenting the ERO. The review was performed to verify the readiness of key Exelon staff to respond to an emergency event and to verify Exelons ability to activate their emergency response facilities (ERF) in a timely manner. The inspectors reviewed the PB Emergency Plan for ERF activation and ERO staffing requirements, the ERO duty roster, applicable station procedures, augmentation test reports, and CA reports related to this inspection area. The inspectors also reviewed a sample of ERO responder training records to verify training and qualifications were up to date.
The inspection was conducted in accordance with NRC IP 71114, Attachment 3.
Title 10 CFR 50.47(b)(2) and related requirements of 10 CFR Part 50, Appendix E, were used as reference criteria.
b. Findings
No findings were identified.
1EP5 Maintaining Emergency Preparedness (EP)
a. Inspection Scope
The inspectors reviewed a number of activities to evaluate the efficacy of Exelons efforts to maintain the PBs EP Program. The inspectors reviewed: memorandums of agreement with offsite agencies; PBs maintenance of equipment important to EP; records of evacuation time estimate and population evaluation; and provisions for, and implementation of, primary, backup, and alternate ERF maintenance.
The inspectors further evaluated Exelons ability to maintain PBs EP program through their identification and correction of EP weaknesses, by reviewing a sample of drill reports, self-assessments, and 10 CFR 50.54(t) reviews. Also, the inspectors reviewed a sample of EP-related issue reports initiated at PBs from March 2015 through March 2017. The inspection was conducted in accordance with NRC IP 71114.05. Title 10 CFR 50.47(b) and the related requirements of 10 CFR Part 50, Appendix E, were used as reference criteria.
b. Findings
No findings were identified.
RADIATION SAFETY
Cornerstone: Occupation Radiation Safety
2RS1 Radiological Hazard Assessment and Exposure Controls
a. Inspection Scope
The inspectors reviewed Exelons performance in assessing and controlling radiological hazards in the workplace. The inspectors used the requirements contained in 10 CFR 20, TSs, applicable Regulatory Guides (RGs), and the procedures required by TSs as criteria for determining compliance.
Inspection Planning
The inspectors reviewed the performance indicators (PIs) for the occupational exposure cornerstone, radiation protection (RP) program audits, and reports of operational occurrences in occupational radiation safety since the last inspection.
Radiological Hazard Assessment ===
The inspectors conducted independent radiation measurements during walkdowns of the facility and reviewed the radiological survey program, air sampling and analysis, continuous air monitor use, recent plant radiation surveys for radiological work activities, and any changes to plant operations since the last inspection to verify survey adequacy of any new radiological hazards for onsite workers or members of the public.
Instructions to Workers (1 sample)
The inspectors reviewed high radiation area (HRA) work permit controls and use; observed containers of radioactive materials and assessed whether the containers were labeled and controlled in accordance with requirements.
The inspectors reviewed several occurrences where a workers electronic personal dosimeter alarmed. The inspectors reviewed Exelons evaluation of the incidents, documentation in the CAP, and whether compensatory dose evaluations were conducted, when appropriate. The inspectors verified follow-up investigations of actual radiological conditions for unexpected radiological hazards were performed.
Contamination and Radioactive Material Control (1 sample)
The inspectors observed the monitoring of potentially contaminated material leaving the radiological controlled area and inspected the methods and radiation monitoring instrumentation used for control, survey, and release of that material. The inspectors selected several sealed sources from inventory records and assessed whether the sources were accounted for and were tested for loose surface contamination. The inspectors evaluated whether any recent transactions involving nationally tracked sources were reported in accordance with requirements.
Radiological Hazards Control and Work Coverage (1 sample)
The inspectors evaluated in-plant radiological conditions and performed independent radiation measurements during facility walk-downs and observation of radiological work activities. The inspectors assessed whether posted surveys; radiation work permits (RWPs); worker radiological briefings and radiation protection job coverage; the use of continuous air monitoring, air sampling and engineering controls; and dosimetry monitoring were consistent with the present conditions. The inspectors examined the control of highly activated or contaminated materials stored within the spent fuel pools and the posting and physical controls for selected HRAs, locked high radiation areas (LHRAs) and very high radiation areas (VHRA) to verify conformance with the occupational performance indicator (PI).
Risk-Significant HRA and VHRA Controls (1 sample)
The inspectors reviewed the procedures and controls for HRAs, VHRAs, and radiological transient areas in the plant.
Radiation Worker Performance and Radiation Protection Technician Proficiency (1 sample)
The inspectors evaluated radiation worker performance with respect to radiation protection work requirements. The inspectors evaluated radiation protection technicians in performance of radiation surveys and in providing radiological job coverage.
Problem Identification and Resolution (1 sample)
The inspectors evaluated whether problems associated with radiation monitoring and exposure control (including operating experience) were identified at an appropriate threshold and properly addressed in the CAP.
b. Findings
No findings were identified.
2RS3 In-Plant Airborne Radioactivity Control and Mitigation
a. Inspection Scope
The inspectors reviewed the control of in-plant airborne radioactivity and the use of respiratory protection devices in these areas. The inspectors used the requirements in 10 CFR 20, RG 8.15, RG 8.25, NUREG/CR-0041, TS, and procedures required by TS as criteria for determining compliance.
Self-Contained Breathing Apparatus (SCBA) for Emergency Use (1 sample)
The inspectors reviewed the following: the status and surveillance records for SCBAs staged in-plant for use during fires, routine operations and emergencies; Exelons SCBA procedures and maintenance and test records; the refilling and transporting of SCBA air bottles; SCBA mask size availability; and the qualifications of personnel performing service and repair of this equipment.
Problem Identification and Resolution (1 sample)
The inspectors evaluated whether problems associated with the control and mitigation of in-plant airborne radioactivity were identified at an appropriate threshold and addressed by Exelons CAP.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator Verification
.1 Unplanned Scrams, Unplanned Power Changes, and Unplanned Scrams with
Complications (6 samples)
a. Inspection Scope
The inspectors reviewed PBs information submitted for the initiating events PIs listed below to assess the accuracy and completeness of the data reported to the NRC for these PIs. The PI definitions and the guidance contained in Nuclear Energy Institute (NEI) 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 6, and Exelon procedure LS-AA-2001, Collecting and Reporting of NRC PI Data, Revision 14, were used to verify that procedure and reporting requirements were met. The inspectors reviewed raw PI data collected from January 1, 2016 to December 31, 2016, and compared graphical representations from the applicable PI reports to the raw data to verify the data was included in the report.
The inspectors also examined a selected sample of operations logs and plant computer thermal power data trends to verify the PI data was appropriately captured for inclusion into the PI report and that the individual PIs were correctly calculated.
- Unit 2 Unplanned Scrams per 7,000 Critical Hours (IE01)
- Unit 3 Unplanned Scrams per 7,000 Critical Hours (IE01)
- Unit 2 Unplanned Power Changes per 7,000 Critical Hours (IE03)
- Unit 3 Unplanned Power Changes per 7,000 Critical Hours (IE03)
- Unit 2 Unplanned Scrams with Complications (IE04)
- Unit 3 Unplanned Scrams with Complications (IE04)
b. Findings
No findings were identified.
.2 EP Performance Indicator Verification
a. Inspection Scope
The inspectors reviewed data for the following three EP PIs:
- (1) drill and exercise performance;
- (2) ERO drill participation; and,
- (3) ANS reliability. The last NRC EP inspection at Peach Bottom was conducted in the second calendar quarter of 2016.
Therefore, the inspectors reviewed supporting documentation from EP drills and equipment tests from the second calendar quarter of 2016 through the fourth calendar quarter of 2016 to verify the accuracy of the reported PI data. The acceptance criteria documented in NEI 99-02, Regulatory Assessment PI Guidelines, Revision 7, was used as reference criteria.
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 IP 71152, Problem Identification and Resolution, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify that Exelon entered issues into the CAP at an appropriate threshold, gave adequate attention to timely CAs, 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 CAP and periodically attended CR screening meetings. The inspectors also confirmed, on a sampling basis, that, as applicable, for identified defects and non-conformances, Exelon performed an evaluation in accordance with 10 CFR Part 21.
b. Findings
No findings were identified
.2 Annual Sample: Trash Rack Cleaning and Frazil Ice Vulnerability Review (1 sample)
a. Inspection Scope
The inspectors performed an in-depth review of Exelon's evaluation and CAs associated with intake structure trash rack cleaning and frazil ice build-up conditions. Specifically, the inspectors reviewed an apparent cause evaluation (ACE) documented in CR 2614867, which evaluated a lowering of intake canal water level that occurred on January 20, 2016, due to partial ice blockage of the non-safety related trash racks and reviewed the history and applicable CAs for other ice blockage issues at PB going back to 2005.
The inspectors reviewed Exelons CA reports, performed intake structure walk downs, reviewed several associated preventive maintenance (PM) activities involving annual diver inspection and cleaning of outer trash rack, intake area inspections and cleaning, silt level measurements and cleaning, and performance of intake canal dredging. In addition, the inspectors reviewed applicable mitigation and icing condition operations procedure AO 29.2, Discharge Canal to Intake Pond Cross-tie gate Operation Frazil Ice mitigation and Icing Condition Operations, to evaluate the quality and effectiveness of the Exelon ice mitigation program, as implemented at PB. Finally, the inspectors interviewed plant personnel, including a diving team supervisor and the system engineer, to evaluate the adequacy of Exelons CAs and to assess the overall performance of the intake cooling water system.
b. Findings and Observations
No findings of significance were identified.
The inspectors reviewed CR 2614867 which described a condition that occurred on January 20, 2016, where operators responded to an indication of lowering water level in the intake canal. Operators identified the lowering intake canal water level was due to ice partially blocking the flow of water from the pond through the non-safety related trash racks. Both maintenance and operations personnel removed ice from in front of the trash racks, restoring adequate flow through the racks and thus returning water level in the intake canal to normal. At that time, operators determined the lowering intake water level was not significant and did not challenge plant safety systems. Exelon staff completed an ACE and compared this incident with recent historical intake canal level lowering incidents at PB due to icing and debris blocking flow through the trash tracks and developed applicable CAs to address the conditions. Inspector review noted that the station properly entered applicable procedures and TSs, including Technical Requirements Manual 3.15, River Level, and SE-3, Loss of Conowingo Pond, until level was restored. Additionally, operator response was in accordance with procedures and training to operate pre-staged ice removal equipment which prevented the canal water level from lowering further.
After discussions with Exelon staff and review of documents, the inspectors noted that there were four instances from 2005 to 2016 in which intake canal water level lowered due to ice and debris buildup decreasing flow through the trash racks. PB investigations determined that in three instances the required PM activity to perform winter cleaning of the trash racks had been re-scheduled so that it was not performed at the optimum and intended time-frame. Prior to 2005, PBAPS had a PM to clean and inspect the bubbler system in the summer time. Subsequently, a new CA from a 2005 ACE was created to perform a second PM for a diver inspection and cleaning of the outer trash rack during the winter around the November or December timeframe. During an ACE due to a lowering intake canal water level incident that occurred in January 2016 (IR 02614867),
Exelon staff identified the winter PM activity had been properly performed from 2008 through 2012. However, their evaluation determined that in the summers of 2013-2015, both PM activities (summer and winter PMs) had been performed during the summer.
Exelon determined their maintenance staff did not fully understand the importance of performing the second PM during the winter months and reasoned that it would be acceptable to perform it earlier. Exelon staff determined that because the winter PM was moved earlier in the year, it was able to be scheduled and completed without additional evaluation required by the PM program. Exelon staff also concluded that performing the winter PM earlier (during the summer) increased the possibility of debris and ice blockage of the intake outer trash rack during the winter months.
The inspectors determined that the failure to ensure PM activities, which were classified as CAs, were implemented to address prior icing occurrences at PB was a performance deficiency (PD). However, based on review of related documentation, interviews with the system engineer and diver supervisor, review of intake structure system design and structural drawings, and review of completed diving inspections and silt removal activities, the inspectors determined that the ice and debris conditions at the PB intake trash racks had limited or only minimal impact on safety systems. Therefore, in accordance with IMC 0612, Section 0612-14, the inspectors determined this PD was minor because it did not adversely affect the mitigating system cornerstone objective of availability, reliability, or capability of the safety-related cooling water systems. The inspectors verified that CAs have been put in place to ensure the winter PM is performed between the months of November and December. In addition the inspectors noted that PB has scheduled and planned actions to replace the remaining five trash racks with new racks that are less susceptible to ice formation, procedure revisions to ensure pre-emptive actions are taken when ice build-up or blockage is suspected, and to perform dredging of the intake canal.
Notwithstanding, the inspectors had two observations regarding CAs. First, the inspectors observed the wording in the PM stated, in part, clean leaves and debris from outer trash racks after fall schedule in November. The inspectors questioned whether the wording was of sufficient clarity to ensure the PM was not completed too early.
Exelon staff initiated IR 3977566 to re-consider the clarity of the PM scheduling guidance.
The inspectors also observed that a PM activity to inspect the area between the trash rack and the outer traveling screen which was deleted without proper evaluation or engineering justification as directed by the PB PM procedure WC-AA-120. In response Exelon staff initiated IR 3977546 to evaluate this condition. Exelon staff determined the likely cause of this deletion involved their staff not properly implementing step 4.1.7 of the PM program procedure which requires, in part, that modifications to critical component or MR PMs receive a technical review by the system manager with final review and approval by an engineering branch manager. The inspectors determined that not implementing this portion of the PM procedure was a PD. However, based on review of related documentation, interviews with the system engineer and diver supervisor, review of intake structure system design and structural drawings, and review of completed diving inspections and silt removal activities, the inspectors determined that silt levels in the area between the trash rack and the outer traveling screens were low and did not impact any of the safety-related pumps.
In accordance with IMC 0612, Section 0612-14, the inspectors determined this PD was minor because it did not adversely affect the mitigating system cornerstone objective of availability, reliability, or capability of the safety-related cooling water systems.
.3 Annual Sample: Station Gaps in Human Performance Tool Usage (1 sample)
a. Inspection Scope
The inspectors performed an in-depth review of Exelons root cause report (RCR) and CAs associated with IR 2646772, which was written to document four events that were caused by inadequate use of human performance tools.
The inspectors assessed Exelons problem identification threshold, cause analyses, extent of condition reviews, compensatory actions, and the prioritization and timeliness of Exelons CAs to determine whether Exelon was appropriately identifying, characterizing, and correcting problems associated with this issue and whether the planned or completed CAs were appropriate. The inspectors compared the actions taken to the requirements of Exelons CAP and 10 CFR 50, Appendix B. In addition, the inspectors interviewed personnel and observed activities to assess the effectiveness of the implemented CAs.
b. Findings and Observations
No findings were identified.
The inspectors noted that Exelon screened and evaluated the four following individual events as potentially similar in their RCR:
- Unit 2 A reactor protection system (RPS) channel half scram when the RPS test box was removed (IR 2588736, November 2015; ACE)
- Wrong test switch manipulated during Unit 2 LSFT (IR 2614949, January 2016; ACE)
- Potable water supply infiltrated with unchlorinated water (IR 2618015, February 2016; ACE)
- Unit 2 electrical transient due to the loss of the E124 load center (IR 2646772, March 2016; RCR)
The first three events occurred over a three month period from late 2015 until early 2016 with each event identifying human error as major causal factor. While the fourth, a more significant event, occurred one month later and caused a transient due to a degradation in main condenser vacuum which without prompt operator actions could have led to a reactor scram. It also involved human error. Although these events were evaluated individually, Exelon decided to perform a root cause investigation (RCI) to address the broader organizational and programmatic aspects of these events. The inspector reviewed PI-AA-125, CAP, and determined that conduct of an RCI for these four events was consistent with the requirements of Section 4.3.3 of this procedure. The inspectors noted that the RCI used many evaluation methods, including: Event and Causal Factor Charting, interviewing, trend data review, and barrier analysis, to determine the root and contributing causes for these events. By using Taproot, another RCI technique, Exelon determined that the root cause was also a generic cause and developed CA to address its broader nature. Exelon identified the root cause as the stations failure to identify and/or correct individuals with at risk behaviors, while a contributing cause of failure to effectively use station accountability programs was also identified.
Exelon considered at risk behaviors as over-confidence, complacency, lack of proficiency, and inaccurate risk perception. The focus of these causes was the human errors that led to these events/issues.
Exelon developed a number of immediate CAs to address the causes for these events, which included, but were not limited to: 1) removing involved parties from assigned parties until remedial training was completed; 2) performing for cause fitness for duty and fatigue assessments; 3) performing work stand downs until appropriate briefings were conducted; and 4) issuing a standing order to use reverse briefs on the proper selection of human error prevention tools. The inspector reviewed each of these immediate CAs and verified that they were all completed by their due dates, the latest of which was June 2016.
As long term CAs, Exelon required each department to modify undesirable behaviors, to reinforce positive behaviors, and effect long term change by placing personnel with at risk behaviors in department excellence programs. To verify the adequacy of these long term actions, the inspector observed a sample of ongoing operations and maintenance activities. These included observation of a maintenance activity to verify the capacity of a HPSW sump pump and also a planned rod sequence exchange during the week of February 13, 2017. Prior to beginning these evolutions, the inspector noted that plant staff used various HU tools described in HU-AA-101, Human Performance Tools and Verification Practices, consistent with the guidance in department excellence plans.
These tools included self-check, peer check, 3-Way communications, and 2 minute drills at the job site. The inspector noted that the implementation of the tools was effective to ensure that these evolutions were performed in a human error free manner. The inspector concluded that Exelon had provided reasonable assurance that the immediate and long term CAs were effective.
4OA5 Other Inspection
.1 Temporary Instruction (TI) 2515/192, Inspection of the Licensees Interim
Compensatory Measures Associated with the Open Phase Condition Design Vulnerabilities in Electric Power System
a. Inspection Scope
The objective of this performance based TI is to verify implementation of interim compensatory measures associated with an open phase condition (OPC) design vulnerability in electric power system for operating reactors. The inspectors conducted an inspection to determine if Exelon had implemented the following interim compensatory measures. These compensatory measures are to remain in place until permanent automatic detection and protection schemes are installed and declared operable for OPC design vulnerability. The inspectors verified the following:
- Exelon had identified and discussed with plant staff the lessons-learned from the OPC events at the US operating plants, including the Byron station OPC event and its consequences. This includes conducting operator training for promptly diagnosing, recognizing consequences, and responding to an OPC event
- Exelon had updated plant operating procedures to help operators promptly diagnose and respond to OPC events on off-site power sources credited for safe shutdown of the plant
- Exelon had established and continue to implement periodic walkdown activities to inspect switchyard equipment such as insulators, disconnect switches, and transmission line and transformer connections associated with the offsite power circuits to detect a visible OPC
- Exelon had ensured that routine maintenance and testing activities on switchyard components have been implemented and maintained. As part of the maintenance and testing activities, Exelon assessed and managed plant risk in accordance with 10 CFR 50.65(a)
- (4) requirements.
b. Findings and Observations
No findings were identified. The inspectors verified the TI criteria were met.
4OA6 Meetings, Including Exit
Quarterly Resident
Exit Meeting Summary
On April 21, 2017, the inspectors presented the inspection results to Pat Navin, Peach Bottom, Site Vice President, and other members of Exelons 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
Exelon Generation Company Personnel
- P. Navin, Site Vice President
- M. Herr, Plant Manager
- N. Alexakos, Emergency Preparedness Manager
- J. Armstrong, Regulatory Assurance Manager
- S. Belitsky, Assistant Maintenance Manager
- P. Breidenbaugh, Maintenance Director
- D. Dullum, Regulatory Assurance Engineer
- S. Eichfeld, Senior Design Engineer
- C. Hardee, Project Manager
- D. Henry, Engineering Director
- B. Holmes, Radiation Protection Manager
- J. Koester, Fire Marshal
- H. McCrory, Radiation Protection Support Manager
- J. McDonald, Requal Lead
- C. Millard, Operations Training Manager
- B. Miller, Project Engineer
- R. Ridge, Dosimetry Physicist
- R. Riley, Rad Waste Shipper
- M. Rubright, Respiratory Physicist
- D. Turek, Operations Director
- M. Weidman, Work Management Director
- B. Wright, System Manager
LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED
Opened/Closed
None.