IR 05000277/2017004
| ML18033A046 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/01/2018 |
| From: | Erin Carfang Division Reactor Projects I |
| To: | Bryan Hanson Exelon Generation Co |
| Carfang E | |
| References | |
| EA-17-207 IR 2017004 | |
| Download: ML18033A046 (40) | |
Text
[Type here]
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION I
2100 RENAISSANCE BOULEVARD, SUITE 100 KING OF PRUSSIA, PA 19406-2713 February 1, 2018 EA-17-207 Mr. Bryan Hanson Senior Vice President, Exelon Generation Company, LLC President and Chief Nuclear Officer, Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 SUBJECT: PEACH BOTTOM ATOMIC POWER STATION - INTEGRATED INSPECTION REPORT 05000277/2017004 AND 05000278/2017004 AND EXERCISE OF ENFORCEMENT DISCRETION
Dear Mr. Hanson:
On December 31, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Peach Bottom Atomic Power Station, Units 2 and 3. On January 12, 2018, the NRC inspectors discussed the results of this inspection with Mr. Matthew Herr, Plant Manager, 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.
The inspectors also reviewed Licensee Event Report 05000278/2017-001-00, which described the details associated with a reactor coolant system pressure boundary leak from a 1-inch socket welded recirculation system instrumentation line on the Unit 3 B recirculation line.
Although this constituted a violation of technical specifications involving the reactor coolant system pressure boundary, the NRC concluded that the issue was not within Exelons ability to foresee and correct, Exelons actions did not contribute to the degraded condition, and the actions taken were reasonable to address the issue. As a result, the NRC did not identify a performance deficiency. A risk evaluation was performed, and the issue was determined to be of very low safety significance (Green). Based on the results of NRCs inspection and assessment of this issue, I have been authorized, after consultation with the Director, Office of Enforcement, and the Regional Administrator, to exercise enforcement discretion, in accordance with NRCs Enforcement Policy Section 2.2.4, Using Traditional Enforcement of Disposition Violations Identified at Power Reactors, and Section 3.10, Reactor Violations With No Performance Deficiencies. 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 10 Code of Federal Regulations (CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
Erin E. Carfang, Acting Branch 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 05000277/2017004 and 05000278/2017004 w/Attachment:
Supplementary Information
REGION I==
Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-56 Report No. 05000277/2017004 and 05000278/2017004 Licensee: Exelon Generation Company, LLC Facility: Peach Bottom Atomic Power Station, Units 2 and 3 Location: Delta, Pennsylvania Dates: October 1, 2017 through December 31, 2017 Inspectors: J. Heinly, Senior Resident Inspector G. Stock, Acting Senior Resident Inspector B. Smith, Resident Inspector J. Cassata, Health Physicist J. DeBoer, Emergency Preparedness Inspector, DRS J. Kulp, Senior Reactor Inspector B. Dionne, Senior Health Physicist Approved By: Erin E. Carfang, Acting Branch Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure
SUMMARY
Inspection Report 05000277/2017004 and 05000278/2017004; 10/01/2017 - 12/31/2017;
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 Nuclear Regulatory Commissions (NRC) program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 6.
No findings were identified during this inspection.
REPORT DETAILS
Summary of Plant Status
Unit 2 began the inspection period at 100 percent rated thermal power (RTP). On October 18, 2017, operators performed a downpower to 57 percent RTP to perform planned waterbox cleaning. On October 19, 2017, operators returned the unit to 100 percent RTP.
On December 15, 2017, operators performed a downpower to 40 percent RTP to perform waterbox cleaning, turbine control valve testing, and troubleshooting on the A reactor recirculation pump upper and lower bearing oil level systems. On December 17, 2017, operators returned the unit to 100 percent RTP and 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 86 percent RTP in end-of-cycle coastdown for refueling outage (RFO) P3R21. On October 22, 2017, operators commenced a shutdown from 78 percent RTP and entered into RFO (P3R21). On November 6, 2017, the Unit 3 mode switch was placed in start-up and the main generator was synchronized to the electrical grid on November 7, 2017. On November 9, 2017, Unit 3 was returned to 100 percent RTP and 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
Winter Readiness - Seasonal Extreme
a. Inspection Scope
The inspectors reviewed PBs readiness for the cold weather conditions during the week of October 13, 2017. The review focused on the high-pressure service water (HPSW)system, the emergency cooling tower, the circulating water pump house, and associated support equipment. The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR), technical specifications (TSs), and the corrective action program (CAP) to determine the temperatures or other seasonal weather conditions that could challenge these systems. The review ensured PBs personnel had prepared adequately for the weather-related 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 weather conditions.
b. Findings
No findings were identified.
1R04 Equipment Alignment
.1 Partial System Walkdowns
a. Inspection Scope
The inspectors performed partial walkdowns of the following systems:
- Unit 2 and Unit 3 standby gas treatment on October 26, 2017
- Unit 3 B shutdown cooling on October 26-27, 2017
- Unit 3 reactor core isolation cooling (RCIC) on November 6, 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, TS, 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.
.2 Full System Walkdown
a. Inspection Scope
During the week of October 30, 2017, the inspectors performed a complete system walkdown of accessible portions of the Unit 3 high-pressure coolant injection (HPCI)system to verify the existing equipment lineup was correct. The inspectors reviewed operating procedures, surveillance tests (STs), drawings, equipment line-up check-off lists, and the UFSAR to verify the system was aligned to perform its required safety functions. The inspectors also reviewed electrical power availability, component lubrication and equipment cooling, hanger and support functionality, and operability of support systems. The inspectors performed field walkdowns of accessible portions of the system to verify as-built system configuration matched plant documentation, and that system components and support equipment remained operable. The inspectors confirmed that systems and components were aligned correctly, free from interference from temporary services or isolation boundaries, environmentally qualified, and protected from external threats. The inspectors also examined the material condition of the components for degradation and observed operating parameters of equipment to verify that there were no deficiencies.
Additionally, the inspectors reviewed a sample of related IRs and WOs to ensure Exelon appropriately evaluated and resolved any deficiencies.
b. Findings
No findings were identified.
1R05 Fire Protection
Resident Inspector Quarterly Walkdowns (71111.05Q - 6 samples)
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 out of service (OOS),degraded or inoperable fire protection equipment, as applicable, in accordance with procedures.
- Unit 3 main condenser (PF-78) on October 24, 2017
- Unit 3 main steam isolation valve (MSIV) room (PF-29) on October 25, 2017
- Unit 3 drywell (PF-32) on October 26, 2017
- Unit 3 torus (proper) (PF-13C) on October 30, 2017
- Unit 2 refuel floor (PF-57) on November 30, 2017
- Unit 3 refuel floor (PF-55) on November 30, 2017
b. Findings
No findings were identified.
1R08 In-service Inspection
a. Inspection Scope
From October 30, 2017 to November 3, 2017, the inspectors conducted an inspection and review of in-service inspection (ISI) activities in order to assess the effectiveness of Exelons program for monitoring degradation of the reactor coolant system (RCS)boundary, risk-significant piping boundaries, and the containment system boundaries during the PB Unit 3 21st RFO.
Non-destructive Examination and Welding Activities (IP Section 02.01)
The inspectors observed a sample of in-process non-destructive examinations (NDE),reviewed completed documentation, and interviewed Exelon personnel to verify that the NDE activities performed as part of the fourth interval, third period, of the PB Unit 3 ISI program were conducted in accordance with the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, 2001 Edition with the 2003 Addenda. For augmented examinations, the inspectors verified that activities were performed in accordance with Exelons augmented inspection program and procedures, and with any applicable industry guidance documents.
The inspectors verified that indications and defects, if present, were dispositioned in accordance with the ASME Code or an NRC-approved alternative, and verified that relevant indications were compared to previous examinations to determine if any changes had occurred.
Activities included a review of ultrasonic testing (UT), magnetic particle testing (MT), dye penetrant testing (PT), radiographic testing, and visual testing (VT). The inspectors reviewed certifications of the NDE technicians performing the examinations and verified that the inspections were performed in accordance with qualified NDE procedures and industry guidance. For UT activities, the inspectors also verified the calibration of equipment used to perform the examinations. The inspectors verified that the test results were reviewed and evaluated by certified Level III NDE personnel and that the parameters used in the test were in accordance with the limitations, precautions, and prerequisites specified in the test procedure.
ASME Code Required Examinations:
- Direct observation of the manual UT weld 10-IB-19 in the residual heat removal (RHR) system.
- Direct observation of the manual UT of welds 12-13-11, 12-13-12, and 12-13-13 in the reactor water cleanup (RWCU) system. Documentation review of manual UT of welds 12-14-11, 12-14-12, and 12-14-13.
- Direct observation of the PT/VT of socket welds RTV-3-02A-5449A/W-1 and
- HV-3-02A-5A/W-22 in the reactor recirculation system.
- Documentation review of the VT (VT-3) of reactor pressure vessel (RPV) stabilizing bars at 270 and 315 degrees (F-A/F.1.40).
- Documentation review of the MT of welded attachment RHRHX-A-LS (IA) on the A RHR heat exchanger (HX).
- Documentation review of the RT of welds 12-13-12, 12-13-13, and 12-13-11A following repair activities.
Other Augmented, License Renewal or Industry Initiative Examinations:
- Direct observation of the manual UT of non-safety related RWCU welds 12-13-12 and 12-13-13 and documentation review for welds 12-14-12 and 12-14-13 satisfying Generic Letter (GL) 88-01 requirements.
- Document review of the remote enhanced VT records of the reactor vessel internals during in-vessel visual inspection activities in accordance with BWRVIP-03.
Specifically, the inspectors reviewed the core spray (CS) sparger bracket welds, feedwater end bracket welds, steam dryer supports, and jet pump components, including the main wedges and the wedge hold down system components.
Review of Previous Indications The inspectors did not review any previous indications because there were no relevant indications from the previous RFO that required evaluation for continued service at this time.
Welding on Pressure Boundary Systems The inspectors reviewed the risk-significant pressure boundary welding activity, including the associated NDE, of the installation of a new 4-inch elbow and associated piping as a corrective action (CA) following discovery of an intergranular stress corrosion cracking indication in weld 12-13-12 in the RWCU system. Specifically, the scope of the activity was to remove and replace a 4-inch elbow and other attached piping which were affected by the indication. The inspectors performed a documentation review of the welding activities to verify that the welding, RT/PT/VT examinations, and final acceptance were performed in accordance with the ASME Code requirements. The inspectors reviewed the welding procedure to ensure it contained the required essential and supplemental essential weld variables and that those variables were within the ranges demonstrated by the supporting qualification record. The repair was performed under WO 4596010.
Identification and Resolution of Problems (IP Section 02.05)
The inspectors reviewed a sample of PB Unit 3 CA reports, which identified NDE indications, deficiencies, and other non-conforming conditions since the previous RFO and during the current outage. The inspectors verified that non-conforming conditions were properly identified, characterized, evaluated, and that CAs were identified and entered into the CAP for resolution.
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 requalification training on October 2, 2017, which involved the mitigation of a scenario with a primary containment leak, anticipated transient without scram (ATWS), and entry into the emergency operating procedures (EOPs). The inspectors evaluated operator performance in the control room simulator during the training and verified completion of risk significant operator actions, including the use of abnormal and EOPs. 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 Unit 3 start up activities on November 7, 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 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.
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 Code of Federal Regulations (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 quality control program during the week of November 13, 2017
- Unit 2 and Unit 3 a(3) assessment during the week of November 27, 2017
- Unit 3 reactor pressure boundary function during the weeks of December 4, and 11, 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.
- Unit 3 reactor cavity flood-up activity (reduced inventory) on October 24, 2017
- Unit 3 reactor cavity drain down activity (reduced inventory) on November 3, 2017
- Unit 3 containment de-inerted on November 8, 2017
- Unit 2 D RHR heat exchanger relief valve maintenance on November 27, 2017
- Unit 2 startup transformer outage on December 4, 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 3 jet pump wedge measurements out-of-tolerance on October 31, 2017
- Unit 3 A safety/relief valve solenoid disconnected wire on November 1, 2017
- Unit 3 shutdown cooling snubber test failures on November 6, 2017
- Unit 2 and Unit 3 E-3 emergency diesel generator (EDG) turbo air inlet and exhaust gas temperatures outside of acceptable range on November 14, 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 IST 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.
1R18 Plant Modification
Permanent Modifications
a. Inspection Scope
The inspectors evaluated the following two modifications:
- Unit 3 digital electro-hydraulic control during the week of November 13, 2017
- Unit 3 digital feedwater during the week of November 20, 2017 The inspectors reviewed 10 CFR 50.59 documentation and post-modification testing results, and conducted field walkdowns of the modifications to verify that the permanent modifications did not degrade the design bases, licensing bases, and performance capability of the affected system.
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 point were performed and checked, and that results adequately demonstrated restoration of the affected safety functions.
- Unit 3 E-13 bus undervoltage relay replacement on October 28, 2017
- Unit 2 and Unit 3 E-1 EDG governor tuning on November 1, 2017
- Unit 3 HPCI outboard steam isolation valve maintenance on November 1, 2017
- Unit 3 B MSIV 86B stroke timing following poppet modification on November 1, 2017
- Unit 3 A CS injection valve maintenance on November 2, 2017
- Unit 3 RCIC valve stroke testing following outage inspection test on November 5, 2017
- Unit 3 HPCI 150 pound flow test during outage start-up following HPCI maintenance on November 9, 2017
b. Findings
No findings were identified.
1R20 Refueling and Other Outage Activities
Unit 3 RFO (P3R21)
a. Inspection Scope
The inspectors reviewed the stations work schedule and outage risk plan for the Unit 3 P3R21 RFO, conducted October 23, 2017 to November 7, 2017. The inspectors reviewed Exelons development and implementation of outage plans and schedules to verify that risk, industry experience, previous site-specific problems, and defense-in-depth were considered. During the outage, the inspectors observed portions of the shutdown and cooldown processes and monitored controls associated with the following outage activities:
- Configuration management, including maintenance of defense-in-depth, commensurate with the outage plan for the key safety functions and compliance with the applicable TSs when taking equipment OOS
- Implementation of clearance activities and confirmation that tags were properly hung and that equipment was appropriately configured to safely support the associated work or testing
- Installation and configuration of reactor coolant pressure, level, and temperature instruments to provide accurate indication and instrument error accounting
- Status and configuration of electrical systems and switchyard activities to ensure that TSs were met
- Monitoring of decay heat removal operations
- Impact of outage work on the ability of the operators to operate the spent fuel pool cooling system
- Reactor water inventory controls, including flow paths, configurations, alternative means for inventory additions, and controls to prevent inventory loss
- Activities that could affect reactivity
- Maintenance of secondary containment as required by TSs
- Fatigue management
- Refueling activities, including fuel handling and fuel receipt inspections
- Tracking of startup prerequisites, walkdown of the drywell (primary containment) to verify that debris had not been left which could block the emergency core cooling system suction strainers, and startup and ascension to full power operation
- Identification and resolution of problems related to RFO activities
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors observed performance of 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 3 A CS injection valve local leak rate testing (LLRT) on October 24, 2017
- Unit 3 A standby liquid control biennial comprehensive in-service test (IST) on October 29, 2017
- Unit 2 and Unit 3 E-33 loss of offsite power (LOOP)/loss-of-coolant accident (LOCA)testing on November 2, 2017
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP4 Emergency Action Level and Emergency Plan Changes
a. Inspection Scope
Exelon implemented various changes to the PB Emergency Action Levels (EALs),
Emergency Plan (EP), and Implementing Procedures. Exelon had determined that, in accordance with 10 CFR 50.54(q)(3), any change made to the EALs, EP, and its lower-tier implementing procedures, had not resulted in any reduction in effectiveness of the Plan, and that the revised Plan continued to meet the standards in 50.47(b) and the requirements of 10 CFR 50 Appendix E.
The inspectors performed an in-office review of all EAL and EP changes submitted by Exelon as required by 10 CFR 50.54(q)(5), including the changes to lower-tier EP implementing procedures, to evaluate for any potential reductions in effectiveness of the EP. This review by the inspectors was not documented in an NRC Safety Evaluation Report and does not constitute formal NRC approval of the changes. Therefore, these changes remain subject to future NRC inspection in their entirety. The requirements in 10 CFR 50.54(q) were used as reference criteria. The specific documents reviewed during this inspection are listed in the Attachment.
b. Findings
No findings were identified.
1EP6 Drill Evaluation
Emergency Preparedness Drill/Simulator Evaluation/Observation
a. Inspection Scope
The inspectors evaluated the shift manager/emergency directors emergency preparedness implementation during a licensed operator out-of-the-box simulator training on October 2, 2017, which involved an ATWS and primary containment failures.
The inspectors observed emergency response operations in the simulator to determine whether event classifications and notifications were performed in accordance with approved procedures. The inspectors also attended the control room simulator drill critique to compare inspector observations with those identified by Exelon staff in order to evaluate whether Exelon staff were properly identifying emergency preparedness weaknesses and entering them into the CAP.
b. Findings
No findings were identified.
RADIATION SAFETY
Cornerstone: Occupational and Public Radiation Safety
2RS0 1 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, TS, applicable regulatory guides (RGs), and the procedures required by TS as criteria for determining compliance.
Radiological Hazard Assessment The inspectors conducted independent radiation measurements during walk-downs 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 The inspectors reviewed radiation work permit (RWP) controls and use in high radiation areas and locked high radiation areas. The inspectors observed containers of radioactive materials and assessed whether the containers were labeled and controlled in accordance with requirements. The inspectors verified follow-up investigations of actual radiological conditions for unexpected radiological hazards were performed.
Contamination and Radioactive Material Control 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.
Radiological Hazards Control and Work Coverage The inspectors evaluated in-plant radiological conditions and performed independent radiation measurements during facility walkdowns and observation of radiological work activities. The inspectors assessed whether posted surveys; 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.
Radiation Worker Performance and Radiation Protection Technician Proficiency 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.
b. Findings
No findings identified.
2RS0 2 Occupational As Low As Reasonably Achievable (ALARA) Planning and Controls
a. Inspection Scope
The inspectors assessed Exelons performance with respect to maintaining occupational individual and collective radiation exposures ALARA. The inspectors used the requirements contained in 10 CFR 20, RGs 8.8 and 8.10, TSs, and procedures required by TSs as criteria for determining compliance.
Radiological Work Planning The inspectors selected the following radiological work activities based on exposure significance for review:
- RWP No. 506, Drywell Scaffolding Activities
- RWP No. 510, Main Steam Safety Relief Valve Activities
- RWP No. 515, Drywell Under-vessel Equipment Maintenance
- RWP No. 548, Drywell Recirculation Pump Seal and Motor Activities
- RWP No. 901 Reactor Disassembly/Reassembly Activities For each of these activities, the inspectors reviewed: ALARA work activity evaluations, exposure estimates, exposure/contamination reduction controls, results achieved (dose rate reductions, actual dose), person-hour estimates and results achieved.
Verification of Dose Estimates and Exposure Tracking Systems The inspectors reviewed the current annual collective dose estimate; basis methodology; and measures to track, trend, and reduce occupational doses for ongoing work activities.
The inspectors evaluated the adjustment of exposure estimates and planning of work.
Implementation of ALARA and Radiological Work Control The inspectors reviewed radiological work controls and ALARA practices during the observation of in-plant work activities. The inspectors verified use of shielding, contamination controls, airborne controls, RWP controls, and other work controls were consistent with ALARA plans.
The inspectors also verified that the ALARA staff was involved with emergent work activities and were revising both dose estimates and ALARA controls in the associated RWPs/ALARA plans, as appropriate.
b. Findings
No findings were identified.
2RS0 3 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.
Engineering Controls The inspectors reviewed operability and use of both permanent and temporary ventilation systems and the adequacy of airborne radioactivity radiation monitoring in the plant based on location, sensitivity, and alarm set-points.
Use of Respiratory Protection Devices The inspectors reviewed the adequacy of Exelons use of respiratory protection devices in the plant to include applicable ALARA evaluations, respiratory protection device certification, respiratory equipment storage, air quality testing records, and individual qualification records.
Problem Identification and Resolution 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.
2RS0 4 Occupational Dose Assessment
a. Inspection Scope
The inspectors reviewed the monitoring, assessment, and reporting of occupational dose. The inspectors used the requirements in 10 CFR 20, RGs, TSs, and procedures required by TSs as criteria for determining compliance.
External Dosimetry The inspectors reviewed: onsite storage of dosimeters; the use of correction factors to align electronic personnel dosimetry results with national voluntary laboratory accreditation program dosimetry results; dosimetry occurrence reports; and CAP documents for adverse trends related to external dosimetry.
Internal Dosimetry The inspectors reviewed: internal dosimetry procedures; whole body counter measurement sensitivity and use; adequacy of the program for whole body count monitoring of plant radionuclides; adequacy of the program for dose assessments based on air sample monitoring and the use of respiratory protection; and internal dose assessments for any actual internal exposure.
Special Dosimetric Situations The inspectors reviewed: Exelons worker notification of the risks of radiation exposure to the embryo/fetus; the dosimetry monitoring program for declared pregnant workers; external dose monitoring of workers in large dose rate gradient environments; and dose assessments performed since the last inspection that used skin dose or neutron dose assessments.
Problem Identification and Resolution The inspectors evaluated whether problems associated with occupational dose assessment were identified at an appropriate threshold and properly addressed in the CAP.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator Verification
.1 Mitigating System Performance Index (MSPI) (12 samples)
a. Inspection Scope
The inspectors reviewed Exelons submittal of the MSPI for the following systems for the period of July 1, 2016, through September 30, 2017:
- Unit 2 and Unit 3 MSPI - Safety System Functional Failures (MS05)
- Unit 2 and Unit 3 MSPI - Cooling Water Systems (MS10)
To determine the accuracy of the performance indicator (PI) data reported during those periods, the inspectors used definitions and guidance contained in Nuclear Energy Institute (NEI) Document 99-02, Regulatory Assessment PI Guideline, Revision 7.
The inspectors also reviewed Exelons operator narrative logs, CRs, MSPI derivation reports, event reports, and NRC integrated inspection reports to validate the accuracy of the submittals.
b. Findings
No findings were identified.
.2 Occupational Exposure Control Effectiveness (1 sample)
a. Inspection Scope
The inspectors reviewed Exelons submittals for the occupational radiological occurrences PI for the period of October 1, 2016 through September 30, 2017. The inspectors used PI definitions and guidance contained in NEI 99-02, Revision 7, to determine the accuracy of the PI data reported. The inspectors reviewed electronic personal dosimetry accumulated dose alarms, dose reports, and dose assignments for any intakes that occurred during the time period reviewed to determine if there were potentially unrecognized PI occurrences. The inspectors conducted walkdowns of various locked high and very high radiation area entrances to determine the adequacy of the controls in place for these areas.
b. Findings
No findings were identified.
.3 Radiological Effluent TSs/Offsite Dose Calculation Manual (ODCM) Radiological Effluent
Occurrences (1 sample)
a. Inspection Scope
The inspectors reviewed licensee submittals for the radiological effluent TS/ODCM radiological effluent occurrences for PI for the period of October 1, 2016 through September 30, 2017. The inspectors used PI definitions and guidance contained in NEI 99-02, Revision 7, to determine if the PI data was reported properly. The inspectors reviewed the public dose assessments for the PI for public radiation safety to determine if related data was accurately calculated and reported.
The inspectors reviewed the CAP database to identify any potential occurrences such as unmonitored, uncontrolled, or improperly calculated effluent releases that may have impacted offsite dose. The inspectors reviewed gaseous and liquid effluent summary data and the results of associated offsite dose calculations to determine if indicator results were accurately reported.
b. Findings
No findings were identified.
4OA2 Problem Identification and Resolution
.1 Routine Review of Problem Identification and Resolution Activities
a. Inspection Scope
As required by Inspection Procedure (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 IR 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: Validation of Emergency Pump Structure Flood Protection
a. Inspection Scope
The inspectors performed an in-depth review of Exelons evaluation and CAs related to validating Exelons emergency pump structure was adequately protected from an external flood as documented in IRs 2708422 and 2711402. Specifically, the NRC had identified several vulnerabilities related to structure in-leakage, bypassing flood barriers, and the testing of credited sump pumps.
The inspectors assessed Exelons implemented and planned CAs to evaluate whether Exelon staff appropriately identified, characterized, prioritized, and corrected problems associated with this issue. The inspectors compared the actions taken to the requirements in Exelon procedure PI-AA-125, CAP Procedure, and the PB Fire Protection Program. The inspectors also reviewed associated documents, conducted interviews with station personnel, and completed field walkdowns to gain an understanding of the implemented and planned CAs associated with this issue.
b. Findings and Observations
No findings were identified.
On August 25, 2016, the NRC identified a potential flood flow path from outside the emergency pump structure via an open 2-inch vent line through the diesel driven fire pump storage tank overfill line and out the flame arrestor located within the emergency pump structure. The vent opening was located below the external flood level found in PB special event procedure, SE-4, Flood, Revision 42.
Exelon generated IR 2708422 and implemented CAs to appropriately cap the vent line, revise SE-4 to provide additional guidance, and calculate the in-leakage of the bypass during the maximum external flood and verify the in-leakage would not exceed the sump pump removal capacity, As a result of additional questions from the IR 2708422 review, Exelons senior leadership team at PB met on August 31, 2016, to develop an action plan to ensure adequate flood protection features existed for the emergency pump structure.
IR 2711402 was generated and specified several CAs to be completed.
Exelon performed a holistic review of the emergency pump structure by performing a reassessment of post-Fukushima inspections, including walking down penetrations, inspecting seals, and reviewing all systems that interacted with the pump structure to determine if any additional flood vulnerabilities existed, similar to the one identified in IR 2708422. Exelon also performed a review of its programmatic controls to ensure routine maintenance did not inadvertently disable flood protection features without proper controls. Furthermore, Exelon determined the design basis in-leakage of the pump structure and revalidated the sump pump removal capacity.
The inspectors reviewed Exelons holistic review of the emergency pump structure external flooding revalidation as well as the CAs performed. The inspectors independently walked down the pump structure and reviewed a sampling of Exelons seal inspections. Finally, the inspectors reviewed the calculation of in-leakage for the pump structure, the test performed of the sump pump capacity, and verified that the equipment within the structure would remain operable during a design basis external flood. The inspectors found that Exelons CAs were sufficient for the identified deficiencies.
.3 Semi-Annual Trend Review
a. Inspection Scope
The inspectors performed a semi-annual review of site issues to identify trends that might indicate the existence of more significant safety issues. As part of this review, the inspectors included as appropriate, repetitive or closely related issues documented by Exelon in trend reports, site PIs, major equipment problem lists, system health reports, MR assessments, and maintenance or CAP backlogs. The inspectors also reviewed Exelons CAP database for the third and fourth quarters of 2017 to assess CRs written in various subject areas (equipment problems, human performance issues, etc.), as well as individual issues identified during the NRCs daily CR review (Section 4OA2.1). The inspectors reviewed Exelons quarterly trend report for the third and fourth quarters of 2017 in the departments of operations, engineering, and maintenance to verify Exelon personnel were appropriately evaluating and trending adverse conditions in accordance with applicable procedures.
b. Findings and Observations
No findings were identified.
The inspectors evaluated a sample of issues and events that occurred over the course of the third and fourth quarters of 2017 to determine whether issues were appropriately considered as emerging or adverse trends. The inspectors verified that these issues were addressed within the scope of the CAP or through department review.
The evaluation did not reveal any new trends that could indicate a more significant safety issue. The inspectors assessed that Exelon personnel were identifying trend issues at a low threshold and entering them into the CAP for resolution and were appropriately prioritizing investigation reviews. The inspectors noted minor adverse trends identified by Exelon staff in the areas of CA process implementation (04040983),thermal overload failures (04030605, 04034958), supplemental workforce performance gaps (04062291), and issues associated with operator medical requirements (04065158).
There were no adverse safety consequences as a result of these low-level trend issues.
Based on the overall results of the semi-annual trend review, the inspectors determined that Exelon was properly identifying adverse trends at Peach Bottom before they became more significant safety problems. The inspectors independently evaluated the deficiencies noted above for significance in accordance with the guidance in Inspection Manual Chapter (IMC) 0612, Appendix B, Issue Screening, and Appendix E, Examples of Minor Issues. The inspectors determined these conditions were deficiencies of minor significance and, therefore, are not subject to enforcement action in accordance with the NRCs Enforcement Policy.
4OA3 Follow-Up of Events and Notices of Enforcement Discretion
(Closed) Licensee Event Report (LER) 05000278/2017-001-00: Reactor Pressure Boundary Leakage Due to Weld Failure in 1-inch Diameter Instrument Line
a. Inspection Scope
On October 23, 2017, during initial walkdown of the containment at the start of the Unit 3 RFO, a leak was identified in a socket weld for a 1-inch diameter pressure transmitter instrument line. The line is connected to discharge piping for the B recirculation pump and is part of the ASME Class 1 primary coolant system pressure boundary. Because the leak was misting, the leakage rate could not be quantified. The apparent cause evaluation (ACE) determined that cause of the crack in the instrument line weld was caused by lack of fusion defects on the inside diameter of the fitting and propagated by normal vibration of the pipe.
The affected section of the pipes and fitting were replaced by new pipe and fitting and replaced with a new socket weld with a 2x1-weld profile, which reduces susceptibility to vibration-induced failures. The LER and associated evaluations and follow-up actions were reviewed for accuracy, the appropriateness of CAs, violations of requirements and potential generic issues. This LER is closed.
b. Findings
Description.
On October 23, 2017, during initial walkdown of the containment at the start of the Unit 3 RFO, a leak was identified in a socket weld for a 1-inch diameter pressure transmitter instrument line. The line is connected to discharge piping for the B recirculation pump and is part of the ASME Class 1 primary coolant system pressure boundary. Because the leak was misting, the leakage rate could not be quantified.
Additionally, Exelon determined that this leakage constituted a violation of the Unit 3, TS 3.4.4, RCS Operational Leakage, that requires that there be no pressure boundary leakage. The condition was reported in event notification 53031, as required by 10 CFR 50.72(b)(3)(ii)(A), because it represented a degradation of a principal safety barrier.
Exelon evaluated the flaw and determined the cause of the RCS pressure boundary leakage was that a crack developed in the weld material of an instrument line socket weld which was caused by lack of fusion defects on the inside diameter of the welded fitting and propagated by normal vibrations of the piping.
The inspectors reviewed the LER and Exelons ACE of the event. The inspectors reviewed the event information and leakage data over the previous cycle and concluded that reactor pressure boundary leakage reasonably began on an unknown date before October 23, 2017, during the operating cycle but more than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> prior to the October 23, 2017, shutdown. However, the inspectors determined that the existence of RCS pressure boundary leakage was not within Exelons ability to foresee and correct and, therefore, was not a performance deficiency (PD). Specifically, the 1-inch socket welds in the recirculation system instrument lines are exempt from periodic examination as described in ASME Section XI Section IWB-1220, Components Exempt from Examination. The inspectors screened the significance of the condition using IMC 0609, Appendix A, The Significance Determination Process For Findings At-Power, and determined that the condition represented very low safety significance (Green), because it would not result in exceeding the RCS leak rate for a small LOCA and would not have likely affected other systems used to mitigate a LOCA.
Enforcement.
TS 3.4.4.a requires, in part, that RCS operational leakage shall be limited to no pressure boundary leakage. If pressure boundary leakage exists, the TS 3.4.4.C limiting condition for operation action statement requires Unit 3 to be in at least hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in cold shutdown within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Contrary to the above, for a period that began on an unknown date that was very likely more than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> before October 23 2017, and ending on October 23, 2017, RCS pressure boundary leakage existed, and Exelon did not place Unit 3 in at least hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in cold shutdown within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
This issue is considered within the traditional enforcement process because there was no PD associated with the violation of NRC requirements. IMC 0612, Power Reactor Inspection Reports, Section 03.22 states, in part, that traditional enforcement is used to disposition violations receiving enforcement discretion or violations without a PD.
The NRC Enforcement Policy, Section 2.2.1 states, in part, that, whenever possible, the NRC uses risk information in assessing the safety significance of violations. Accordingly, after considering that the condition represented very low safety significance, the inspectors concluded that the violation would be best characterized as Severity Level IV under the traditional enforcement process. However, the NRC is exercising enforcement discretion (EA-17-207) in accordance with Section 3.10 of the NRC Enforcement Policy, which states that the NRC may exercise discretion for violations of NRC requirements by reactor licensees for which there are no associated PD. In reaching this decision, the NRC determined that the issue was not within the licensees ability to foresee and correct; the licensees actions did not contribute to the degraded condition; and the actions taken were reasonable to identify and address the condition. Furthermore, because the licensees actions did not contribute to this violation, it will not be considered in the assessment process or the NRCs action matrix.
4OA6 Meetings, Including Exit
On January 12, 2018, the inspectors presented the inspection results to Matthew Herr, Plant Manager, 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 Personnel
- P. Navin, Site Vice President
- M. Herr, Plant Manager
- N. Alexakos, Emergency Preparedness Manager
- J. Armstrong, Regulatory Assurance Manager
- D. Baracco, Radiation Protection Manager
- C. Crabtree, Chemistry Groundwater Engineer
- D. Dullum, Regulatory Assurance Engineer
- S. Griffith, Manager Site Security
- G. Gustofson, Exelon NDE Supervisor
- J. Hawkins, Exelon NDE Supervisor
- D. Henry, Operations Director
- S. Hess, Engineering Director
- B. Holmes, Radiation Protection Manager
- D. Hornberger, Chemistry/Radwaste
- P. Kester, Senior Design Engineer
- B. Miller, Fire Protection Engineer
- M. Rector, Engineering Response Team Manager
- M. Retzer, Senior Manager Systems Engineering
- R. Ridge, Health Physicist
- R. Riley, Radwaste Shipper
- J. Stenclik, Chemistry Supervisor
- M. Weidman, Work Management Director
- T. Wickle, Senior Design Manager
LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED
Closed
- 05000278/2017-001-00 LER Reactor Pressure Boundary Leakage Due to Weld Failure in 1-inch Diameter Instrument Line (Section 4OA3)