IR 05000261/2016002
| ML16214A035 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 07/29/2016 |
| From: | Hopper G NRC/RGN-II/DRP/RPB4 |
| To: | Glover R Duke Energy Corp |
| References | |
| IR 2016002 | |
| Download: ML16214A035 (28) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION uly 29, 2016
SUBJECT:
H.B. ROBINSON STEAM ELECTRIC PLANT - NRC INTEGRATED INSPECTION REPORT 05000261/2016002
Dear Mr. Glover:
On June 30, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your H. B. Robinson Steam Electric Plant, Unit 2. On July 13, 2016, the NRC inspectors discussed the results of this inspection with Mr. John Krakuszeski and other members of your staff. Inspectors documented the results of this inspection in the enclosed inspection report.
No NRC-identified or self-revealing findings were identified during this inspection. However, inspectors documented a licensee-identified violation which was determined to be of very low safety significance in this report. The NRC is treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.
If you contest the violations or significance of the NCVs, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington DC 20555-0001; with copies to the Regional Administrator, Region II, the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspector at H.B. Robinson Steam Electric Plant, Unit 2. In accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding, of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRCs Public Document Room or from the Publicly Available Records (PARS) component of the NRCs Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
George T. Hopper, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket No.: 50-261 License No.: DPR-23
Enclosure:
IR 05000261/2016002 w/Attachment: Supplemental Information
REGION II==
Docket No: 50-261 License No: DPR-23 Report No: 005000261/2016002 Licensee: Duke Energy Progress, Inc.
Facility: H. B. Robinson Steam Electric Plant, Unit 2 Location: 3581 West Entrance Road Hartsville, SC 29550 Dates:
April 1, 2016 through June 30, 2016 Inspectors:
K. Ellis, Senior Resident Inspector S. Herrick, Reactor Inspector C. Rapp, Senior Project Engineer J. Dodson, Senior Project Engineer C. Dykes, Health Physics Inspector A. Beasten, Resident Inspector (Training)
S. Sanchez, Senior Emergency Preparedness Inspector C. Fontana, Emergency Preparedness Inspector J. Hickman, Emergency Preparedness Inspector (Training)
Approved by: George T. Hopper, Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure
SUMMARY
IR 05000261/2016002, April 1, 2016, through June 30, 2016; Duke Energy Progress, Inc.,
H. B. Robinson Steam Electric Plant, Unit 2, Integrated Inspection Report.
The report covered a three-month period of inspection by resident inspectors and regional inspectors. The significance of inspection findings are indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC)0609, Significance Determination Process (SDP) dated April 29, 2015. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy dated February 4, 2015. The NRCs program for overseeing the safe operations of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision
Licensee-Identified Violations
A violation of very low safety significance that was identified by the licensee has been reviewed by the NRC. Corrective actions taken or planned by the licensee have been entered into the licensees corrective action program (CAP). This violation and corrective action tracking number is listed in Section 4OA7 of this report.
REPORT DETAILS
Summary of Plant Status
The unit began the inspection period at 100 percent rated thermal power (RTP). The unit was downpowered to 50 percent RTP on May 20, 2016, for turbine valve testing and returned to 100 percent RTP on May 21, 2016, and remained there for the remainder of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
a. Inspection Scope
.1 Summer Readiness of Offsite and Alternate AC Power System
The licensee did not implement equipment or procedure changes that potentially affect operation or reliability of offsite and alternate AC power systems since the last time the inspectors assessed grid reliability. The inspectors reviewed the material condition of offsite and onsite alternate AC power systems (including switchyard and transformers)by performing a walkdown of the switchyard. Documents reviewed are listed in the
.
.2 Seasonal Extreme Weather Conditions
The inspectors conducted a detailed review of the stations adverse weather procedures and compensatory measures, including operator staffing, before the onset of extreme high temperatures. The inspectors verified that weather-related equipment deficiencies identified during the previous year had been placed into the work control process and/or corrected before the onset of seasonal extremes. The inspectors evaluated the licensees implementation of adverse weather preparation procedures and compensatory measures before the onset of seasonal extreme weather conditions. The inspectors verified that plant features and procedures for operation and continued availability of the ultimate heat sink during adverse weather are appropriate. Documents reviewed are listed in the attachment. The inspectors evaluated the following risk-significant systems:
- Service Water System
- Containment Ventilation System
b. Findings
No findings were identified.
1R04 Equipment Alignment
a. Inspection Scope
.1 Partial Walkdown
The inspectors verified that critical portions of the selected systems were correctly aligned by performing partial walkdowns. The inspectors selected systems for assessment because they were a redundant or backup system or train, were important for mitigating risk for the current plant conditions, had been recently realigned, or were a single-train system. The inspectors determined the correct system lineup by reviewing plant procedures and drawings. Documents reviewed are listed in the Attachment.
The inspectors selected the following systems or trains to inspect:
- Motor-Driven Auxiliary Feedwater (MDAFW) Pump B while the MDAFW pump A was OOS for maintenance
- Auxiliary Feedwater (AFW) Pump C while the Steam-Driven Auxiliary Feedwater Pump was OOS for maintenance
b. Findings
No findings were identified.
1R05 Fire Protection
a. Inspection Scope
1. Quarterly Inspection
The inspectors evaluated the adequacy of selected fire plans by comparing the fire plans to the defined hazards and defense-in-depth features specified in the fire protection program. In evaluating the fire plans, the inspectors assessed the following items:
- control of transient combustibles and ignition sources
- fire detection systems
- water-based fire suppression systems
- gaseous fire suppression systems
- manual firefighting equipment and capability
- passive fire protection features
- compensatory measures and fire watches
- issues related to fire protection contained in the licensees corrective action program The inspectors toured the following fire areas to assess material condition and operational status of fire protection equipment. Documents reviewed are listed in the
.
- Pipe Alley, fire zone 1
- 1st Floor Turbine Building, fire zone 25A/25B
- 115KV/230KV Switchyard
- E1/E2 Switchgear Room, fire zone 20
- B Diesel Generator Room, fire zone 1
- A and B Battery Room, fire zone 16
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification Program and Licensed Operator Performance
a. Inspection Scope
.1 Resident Inspector Quarterly Review of Licensed Operator Requalification
The inspectors observed a simulator scenario administered to an operating crew conducted in accordance with the licensees accredited requalification training program.
The scenario on June 14, 2016, evaluated the operators ability to respond to a steam generator tube leak and rupture, and various equipment malfunctions which resulted in a reactor trip. The inspectors assessed the following:
- licensed operator performance
- the ability of the licensee to administer the scenario and evaluate the operators
- the quality of the post-scenario critique
- simulator performance Documents reviewed are listed in the Attachment.
.2 Resident Inspector Quarterly Review of Licensed Operator Performance in the Actual
Plant/Main Control Room The inspectors observed licensed operator performance in the main control room during a scheduled downpower from 100 percent power to less than 50 percent power for turbine valve testing. The inspectors reviewed the operator performance and adherence to the operating procedures. The inspectors assessed the following:
- use of plant procedures
- control board manipulations
- communications between crew members
- use and interpretation of instruments, indications, and alarms
- use of human error prevention techniques
- documentation of activities
- management and supervision Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R12 Maintenance Effectiveness
a. Inspection Scope
The inspectors assessed the licensees treatment of the issues listed below to verify the licensee appropriately addressed equipment problems within the scope of the maintenance rule (10 CFR 50.65, Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants). The inspectors reviewed procedures and records to evaluate the licensees identification, assessment, and characterization of the problems as well as their corrective actions for returning the equipment to a satisfactory condition. The inspectors also interviewed system engineers and the maintenance rule coordinator to assess the accuracy of performance deficiencies and extent of condition.
Documents reviewed are listed in the Attachment.
- CR 2016522, Investigate/Repair DSDG Soak Back Pump Delayed Start
- CR 5888746, A AFW Outboard Packing Gland Channel Clogged
b. Findings
No findings were identified.
1R13 Maintenance Risk Assessments and Emergent Work Control
a. Inspection Scope
The inspectors reviewed the maintenance activities listed below to verify that the licensee assessed and managed plant risk as required by 10 CFR 50.65(a)(4) and licensee procedures. The inspectors assessed the adequacy of the licensees risk assessments and implementation of risk management actions. The inspectors also verified that the licensee was identifying and resolving problems with assessing and managing maintenance-related risk using the corrective action program. Additionally, for maintenance resulting from unforeseen situations, the inspectors assessed the effectiveness of the licensees planning and control of emergent work activities.
Documents reviewed are listed in the Attachment.
- June 14, 2016, A Train Work Week, Steam Driven Auxiliary Feedwater Pump OOS for maintenance with Circulation Water Pump C OOS for Maintenance
- Review of Critical Activity Plan for A EDG 2 Year Outage
b. Findings
No findings were identified.
1R15 Operability Determinations and Functionality Assessments
a. Inspection Scope
The inspectors selected the operability determinations or functionality evaluations listed below for review based on the risk-significance of the associated components and systems. The inspectors reviewed the technical adequacy of the determinations to ensure that technical specification (TS) operability was properly justified and the components or systems remained capable of performing their design functions. To verify whether components or systems were operable, the inspectors compared the operability and design criteria in the appropriate sections of the TSs and Updated Final Safety Analysis Report to the licensees evaluations. Where compensatory measures were required to maintain operability, the inspectors determined whether the measures in place would function as intended and were properly controlled. Additionally, the inspectors reviewed a sample of corrective action documents to verify the licensee was identifying and correcting any deficiencies associated with operability evaluations.
Documents reviewed are listed in the Attachment.
- CR 1992738, FSL-1633B, AFW PMP-B Not Indicating Properly
- CR 2012658, [Main Stem Line Break (MSLB)] Unanalyzed Condition
- CR 2033744, Investigate/Repair DSD Ventilation Fan B Overload
- EC 402270, Evaluation of South Carolina Rainfall event October 2-5, 2015
- CR 2031851, Spray Additive Tank level calibration does not meet SR frequency
b. Findings
No findings were identified.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors either observed post-maintenance testing or reviewed the test results for the maintenance activities listed below to verify the work performed was completed correctly and the test activities were adequate to verify system operability and functional capability.
- WO 20077722, OST-603-1, Engine Driven Pump Test following maintenance
- WO 13339012, PM-402, Inspection and testing of inertial latch bushing for breaker 52/19B
- WO 13514555, PIC-002, Calibration of D/P Electronic Transmitter LT-969
- WO 13389858, OST-603-2, Motor Driven Fire Pump Test following replacement of motor driven fire pump local control switch replacement
- WO 13462951, OST 409-1, EDG A fast speed start following two-year maintenance outage The inspectors evaluated these activities for the following:
- Acceptance criteria were clear and demonstrated operational readiness.
- Effects of testing on the plant were adequately addressed.
- Test instrumentation was appropriate.
- Tests were performed in accordance with approved procedures.
- Equipment was returned to its operational status following testing.
- Test documentation was properly evaluated.
Additionally, the inspectors reviewed a sample of corrective action documents to verify the licensee was identifying and correcting any deficiencies associated with post-maintenance testing. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors reviewed the surveillance tests listed below and either observed the test or reviewed test results to verify testing adequately demonstrated equipment operability and met TS and licensee procedural requirements. The inspectors evaluated the test activities to assess for preconditioning of equipment, procedure adherence, and equipment alignment following completion of the surveillance. Additionally, the inspectors reviewed a sample of related corrective action documents to verify the licensee was identifying and correcting any deficiencies associated with surveillance testing. Documents reviewed are listed in the Attachment.
Routine Surveillance Tests
- MST-021, Reactor Protection Logic Train B at Power
- MST-005, Pressurizer Water Level Protection Channel Testing
- OST-551-1, Turbine Valve Test
- OST-011, Quarterly Rod Exercise RCS Leakrate
- OST-051, Reactor Coolant System Leakage Evaluation In-Service Tests
- OST-201-2, MDAFW System Component Test - Train B
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP2 Alert and Notification System Evaluation (711114.02 - 1 sample)
a. Inspection Scope
The inspectors evaluated the adequacy of the licensees methods for testing and maintaining the alert and notification system in accordance with NRC Inspection Procedure 71114, Attachment 02, Alert and Notification System Evaluation. The applicable planning standard, 10 CFR Part 50.47 (b) (5), and its related 10 CFR Part 50, Appendix E requirements were used as reference criteria. The criteria contained in NUREG-0654, Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants, Revision 1, were also used as a reference. The inspectors reviewed various documents which are listed in the Attachment, interviewed personnel responsible for system performance, and observed aspects of periodic siren maintenance and testing. This inspection activity satisfied one inspection sample for the alert and notification system on a biennial basis.
b. Findings
No findings were identified.
1EP3 Emergency Response Organization Staffing and Augmentation System (711114.03 -
1 sample)
a. Inspection Scope
The inspectors reviewed the licensees Emergency Response Organization (ERO)augmentation staffing requirements and process for notifying the ERO to ensure the readiness of key staff for responding to an event and timely facility activation. The qualification records of key position ERO personnel were reviewed to ensure all ERO qualifications were current. A sample of problems identified from augmentation drills or system tests performed since the last inspection was reviewed to assess the effectiveness of corrective actions. The inspection was conducted in accordance with NRC Inspection Procedure 71114, Attachment 03, Emergency Response Organization Staffing and Augmentation System. The applicable planning standard, 10 CFR 50.47(b)(2), and its related 10 CFR Part 50, Appendix E requirements were used as reference criteria.
The inspectors reviewed various documents which are listed in the Attachment. This inspection activity satisfied one inspection sample for the ERO staffing and augmentation system on a biennial basis.
b. Findings
No findings were identified.
1EP4 Emergency Action Level and Emergency Plan Changes (711114.04 - 1 sample)
a. Inspection Scope
Since the last NRC inspection of this program area, two changes were made to the Radiological Emergency Plan and two changes were made to the emergency action levels (EALs), along with changes to several implementing procedures. The licensee determined that, in accordance with 10 CFR 50.54(q), the Plan continued to meet the requirements of 10 CFR 50.47(b) and Appendix E to 10 CFR Part 50. The inspectors reviewed these changes to evaluate for potential reductions in the effectiveness of the Plan. However, this review was not documented in a 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 inspection was conducted in accordance with NRC Inspection Procedure 71114, Attachment 04, Emergency Action Level and Emergency Plan Changes. The applicable planning standards of 10 CFR 50.47(b), and its related requirements in 10 CFR 50, Appendix E were used as reference criteria. The inspectors reviewed various documents that are listed in the Attachment to this report. This inspection activity satisfied one inspection sample for the emergency action level and emergency plan changes on an annual basis.
b. Findings
No findings were identified.
1EP5 Maintenance of Emergency Preparedness (711114.05 - 1 sample)
a. Inspection Scope
The inspectors reviewed the corrective actions identified through the Emergency Preparedness program to determine the significance of the issues, the completeness and effectiveness of corrective actions, and to determine if issues were recurring. The licensees post-event after action reports, self-assessments, and audits were reviewed to assess the licensees ability to be self-critical, thus avoiding complacency and degradation of their emergency preparedness program. Inspectors reviewed the licensees 10 CFR 50.54(q) change process, personnel training, and selected screenings and evaluations to assess adequacy. The inspectors toured facilities and reviewed equipment and facility maintenance records to assess licensees adequacy in maintaining them. The inspectors evaluated the capabilities of selected radiation monitoring instrumentation to adequately support EAL declarations. The inspection was conducted in accordance with NRC Inspection Procedure 71114, Attachment 05, and Maintenance of Emergency Preparedness. The applicable planning standards, related 10 CFR 50, Appendix E requirements, and 10 CFR 50.54(q) and
- (t) were used as reference criteria. The inspectors reviewed various documents which are listed in the
. This inspection activity satisfied one inspection sample for the maintenance of emergency preparedness on a biennial basis.
b. Findings
No findings were identified.
1EP6 Drill Evaluation
a. Inspection Scope
The inspectors observed the emergency preparedness drill conducted on April 6, 2016, and May 25, 2016. The inspectors observed licensee activities in the simulator to evaluate implementation of the emergency plan, including event classification, notification, and protective action recommendations. The inspectors evaluated the licensees performance against criteria established in the licensees procedures.
Additionally, the inspectors reviewed the post-exercise critique to assess the licensees effectiveness in identifying emergency preparedness weaknesses and verified the identified weaknesses were entered in the corrective action program. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator Verification
a. Inspection Scope
The inspectors reviewed a sample of the performance indicator (PI) data, submitted by the licensee, for Unit 2 PIs listed below. The inspectors reviewed plant records compiled between April 1, 2015, and March 31, 2016, to verify the accuracy and completeness of the data reported for the station. The inspectors verified that the PI data complied with guidance contained in Nuclear Energy Institute 99-02, Regulatory Assessment Performance Indicator Guideline, and licensee procedures. The inspectors verified the accuracy of reported data that were used to calculate the value of each PI. In addition, the inspectors reviewed a sample of related corrective action documents to verify the licensee was identifying and correcting any deficiencies associated with PI data.
Documents reviewed are listed in the Attachment.
Cornerstone: Initiating Events
- unplanned power changes
Cornerstone: Mitigating Systems
- emergency ac
- safety system functional failures Emergency Preparedness Cornerstone
- Drill/Exercise Performance (DEP)
- Emergency Response Organization (ERO) Readiness
- Alert and Notification System (ANS) Reliability For the specified review period, the inspectors examined data reported to the NRC, procedural guidance for reporting PI information, and records used by the licensee to identify potential PI occurrences. The inspectors verified the accuracy of the PI for ERO drill and exercise performance through review of a sample of drill and event records.
The inspectors reviewed selected training records to verify the accuracy of the PI for ERO drill participation for personnel assigned to key positions in the ERO. The inspectors verified the accuracy of the PI for alert and notification system reliability through review of a sample of the licensees records of periodic system tests. The inspectors also interviewed the licensee personnel who were responsible for collecting and evaluating the PI data. Licensee procedures, records, and other documents reviewed within this inspection area are listed in the Attachment.
b. Findings
No findings were identified.
4OA2 Problem Identification and Resolution
.1 Routine Review
The inspectors screened items entered into the licensees CAP to identify repetitive equipment failures or specific human performance issues for follow-up. The inspectors reviewed condition reports, attended screening meetings, or accessed the licensees computerized corrective action database.
.2 Annual Follow-up of Selected Issues
a. Inspection Scope
The inspectors conducted a detailed review of CR 682160, Indicated Battery Fault for ELS-113 (DS/SBO Light).
The inspectors evaluated the following attributes of the licensees actions:
- complete and accurate identification of the problem in a timely manner
- evaluation and disposition of operability and reportability issues
- consideration of extent of condition, generic implications, common cause, and previous occurrences
- classification and prioritization of the problem
- identification of any additional condition reports
- completion of corrective actions in a timely manner Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.3 Semi-Annual Trend Review
a. Inspection Scope
The inspectors reviewed issues entered in the licensees corrective action program and associated documents to identify trends that could indicate the existence of a more significant safety issue. The inspectors focused their review on repetitive equipment issues and human performance trends but also considered the results of inspector daily condition report screenings, licensee trending efforts, and licensee human performance results. The review nominally considered the 6-month period of January 2016 through June 2016, although some examples extended beyond those dates when the scope of the trend warranted. The inspectors compared their results with the licensees analysis of trends. Additionally, the inspectors reviewed the adequacy of corrective actions associated with a sample of the issues identified in the licensees trend reports. The inspectors also reviewed corrective action documents that were processed by the licensee to identify potential adverse trends in the condition of structures, systems, and/or components as evidenced by acceptance of long-standing non-conforming or degraded conditions. Documents reviewed are listed in the Attachment.
b. Findings and Observations
No findings were identified.
4OA3 Follow-up of Events and Notices of Enforcement Discretion
a. Inspection Scope
(Closed) Licensee Event Report 2016-002-00, Unanalyzed Condition Related to Main Steam Line Break Inside Containment On April 13, 2016, it was determined that the source document for the mass and energy release parameters used to determine the containment pressure and temperature response to a main steam line break inside containment does not adequately account for all possible single active failure scenarios in the steam or feedwater line provisions. The document does not address the failure of a feedwater regulating bypass valve (FRBV) to close in the feedline of a faulted steam generator. An active failure of a FRBV to close will increase the secondary mass available for release into containment and result in higher peak containment pressure that could challenge containment design pressure.
This condition is a concern while the bypass valves are in the open position in Modes 1, 2, or 3. The licensee determined that the postulated single failure of the FRBV to close following a MSLB inside containment was not considered during the establishment of the plants current licensing basis. The licensee entered this issue into the CAP as 2012658 and implemented a standing instruction relating to the use of the FRBVs. The inspectors reviewed the licensee event report, appropriateness of corrective actions, violations of requirements, and generic issues.
b. Findings
The enforcement aspects of this violation are documented in Section 4OA7. This LER is closed.
4OA5 Other Activities
.1 Operation of an Independent Spent Fuel Storage Installation (IP 60855.1)
a. Inspection Scope
The inspectors performed a walkdown of the onsite ISFSI. The inspectors reviewed changes made to the ISFSI programs and procedures, including associated 10 CFR 72.48, Changes, Tests, and Experiments, screens and evaluations to verify that changes made were consistent with the license or certificate of compliance. The inspectors also reviewed surveillance records to verify that surveillance requirements were performed as required by TSs. Documents reviewed are listed in the attachment.
b. Findings
No findings were identified.
4OA6 Meetings, Including Exit
On July 13, 2016, the inspectors presented the inspection results to Mr. John Krakuszeski and other members of the licensees staff. The inspectors confirmed that proprietary information was not retained by the inspectors or documented in this report.
4OA7 Licensee-Identified Violations
The following licensee-identified violation of NRC requirements was determined to be of very low safety significance and met the NRC Enforcement Policy criteria for being dispositioned as a non-cited violation.
Section 50.55a(h)(2) of 10 CFR states in part, for nuclear power plants with construction permits issued before January 1, 1971, protection systems must be consistent with their licensing basis or may meet the requirements of Institute of Electrical and Electronic Engineers (IEEE) Std. 603-1991 and the correction sheet dated January 30, 1995. The Robinson FSAR (current licensing basis) Section 3.1.2.20, states in part that, reactor protection is designed to meet all presently defined reactor protection criteria and is in accordance with the proposed Institute of Electrical and Electronic Engineers (IEEE) 279 Standard for Nuclear Plant Protection Systems, August 1968. IEEE-279, Section 4.2, requires that any single failure within the protection system shall not prevent proper protection system action when required. Contrary to this requirement, from initial startup, until April 13, 2016, when using a FRBV (i.e., FRBV in the open position in Modes 1, 2, and 3), and a MSLB occurred, the protection system would not provide the proper system protection action. Specifically, with a single failure of the FRBV to close, the protective system action to isolate feedwater could not be accomplished. This would cause an increase in secondary mass available for release in containment structure, resulting in a higher peak containment pressure that would challenge the containment design pressure.
As corrective actions, the licensee implemented a standing instruction and placed caution tags on the FRBVs to ensure the valves remain closed/isolated while operating in Modes 1, 2, and 3. Additionally, the licensee completed an engineering change to update the containment analysis and licensing basis. The licensee entered this issue into the CAP as CRs 2012658, 2020495, and 2018710.
The failure to meet the single failure criterion for feedwater isolation following a main steam line break inside containment was a performance deficiency (PD). Significance Determination Process (SDP) screening in accordance with NRC IMC 0609.04 determined that the PD affected the secondary short term heat removal safety function of the mitigating systems cornerstone. The finding was determined to represent a loss of function and a detailed risk assessment was performed per NRC IMC 0609 Appendix A. The bounding analysis assumed a conditional core damage probability of 1.0, a 14 day exposure period estimated from surveillance and outage schedules, and main steam line break inside containment (MSLBIC) initiating event probability and main feedwater regulating valve bypass (MFWRVBV) failure to close probabilities from the NRC SPAR model data. The dominant sequence was an MSLBIC with a failure to close of the MFWRVBV which was assumed to lead to core damage and large early release. The risk was mitigated by short exposure period and the low likelihood of the MSLBIC and the failure to close of the MFWRVBV. The bounding analysis determined that the PD represented a risk increase of < 1.0E-7/year, a GREEN finding of very low safety significance for both core damage frequency and large early release frequency.
ATTACHMENT:
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee personnel
- M. Austin, Emergency Preparedness Corporate Functional Area Manager
- N. Baker, Emergency Preparedness Specialist
- L. Basta, Assistant Operations Manager
- C. Caudell, Regulatory Affairs
- J. Conder, Assistant Operations Training Manager
- S. Connelly, Regulatory Affairs Manager
- P. Fagan, Director, Engineering
- F. Giannone, Training Manager
- M. Glover, Site Vice President
- T. Giese, Manager, Operations Training
- D. Hall, Nuclear Oversite Manager
- E. Hedderman, Chemistry Manager
- D. Hoffman, Organizational Effectiveness Director
- K. Holbrook, Operations Manager
- L. Jackson, Emergency Preparedness Specialist
- J. Kammer, General Manager, Engineering
- T. Kirwin, Manager, Maintenance
- J. Krakuszeski, Plant General Manager
- B. Nanney, Manager, Nuclear Emergency Preparedness
- C. Orr, Manager, Operations and Support
- M. Pastva, Jr., Nuclear Regulatory Affairs
- T. Pilo, Manager, Emergency Preparedness
- D. Pitsley, Manager, Operations
- J. Rackley, Training Supervisor
- C. Sherman, Radiation Protection Superintendent
- N. Tart, Emergency Preparedness Specialist
- D. Thompson, Corporate Functional Area Manager - Radiation Protection
- J. Wild, Regulatory Affairs
NRC personnel
- G. Hopper, Chief, Reactor Projects Branch 4
- K. Ellis, Sr. Resident Inspector
LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Closed
- 05000261/2016-002 LER Unanalyzed Condition Related to Main Steam Line Break Inside Containment (Section 4OA3)