IR 05000443/2015007
ML15119A056 | |
Person / Time | |
---|---|
Site: | Seabrook ![]() |
Issue date: | 04/28/2015 |
From: | Paul Krohn Engineering Region 1 Branch 2 |
To: | Dean Curtland NextEra Energy Seabrook |
References | |
IR 2015007 | |
Download: ML15119A056 (24) | |
Text
ril 28, 2015
SUBJECT:
SEABROOK STATION, UNIT NO. 1 - NRC EVALUATION OF CHANGES, TESTS, AND EXPERIMENTS AND PERMANENT PLANT MODIFICATIONS TEAM INSPECTION REPORT 05000443/2015007
Dear Mr. Curtland:
On March 19, 2015, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Seabrook Station, Unit No. 1. The enclosed inspection report documents the inspection results, which were discussed on March 19, 2015, with you and other members of your staff.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
In conducting the inspection, the team reviewed selected procedures, calculations and records, observed activities, and interviewed station personnel.
Based on the results of the inspection, no findings were identified.
In accordance with 10 CFR 2.390 of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for the public inspection in the NRC Public Docket Room or from the Publicly Available Records component of NRCs document 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/
Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety
Mr. Dean Curtland Vice President, Seabrook Station c/o Mr. Michael Ossing NextEra Energy Seabrook, LLC 626 Lafayette Rd.
Seabrook, NH 03874 SUBJECT: SEABROOK STATION, UNIT NO. 1 - NRC EVALUATION OF CHANGES, TESTS, AND EXPERIMENTS AND PERMANENT PLANT MODIFICATIONS TEAM INSPECTION REPORT 05000443/2015007
Dear Mr. Curtland:
On March 19, 2015, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Seabrook Station, Unit No. 1. The enclosed inspection report documents the inspection results, which were discussed on March 19, 2015, with you and other members of your staff.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
In conducting the inspection, the team reviewed selected procedures, calculations and records, observed activities, and interviewed station personnel.
Based on the results of the inspection, no findings were identified.
In accordance with 10 CFR 2.390 of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for the public inspection in the NRC Public Docket Room or from the Publicly Available Records component of NRCs document 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/
Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety Distribution: See Next Page DOCUMENT NAME: G:\DRS\Plant Support Branch 2\Lilliendahl\Seabrook MODS 2015007.docx ADAMS ACCESSION NUMBER: ML15119A056 Non-Sensitive Publicly Available SUNSI Review Sensitive Non-Publicly Available OFFICE RI/DRS RI/DRP RI/DRS NAME JLilliendahl GDentel/RB PKrohn DATE 4/17/15 4/21/15 4/28/15 Docket No. 50-443 License No: NPF-86
Enclosure:
Inspection Report No. 05000443/2015007 w/ Attachment: Supplemental Information
REGION I==
Docket No.: 50-443 License No.: NPF-86 Report No.: 05000443/2015007 Licensee: NextEra Energy Seabrook, LLC Facility: Seabrook Station, Unit No.1 Location: Seabrook, New Hampshire 03874 Inspection Period: March 2 through March 19, 2015 Inspectors: J. Lilliendahl, Senior Emergency Response Coordinator, Division of Reactor Safety (DRS), Team Lead S. Pindale, Senior Reactor Inspector, DRS J. Schoppy, Senior Reactor Inspector, DRS Approved By: Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety i Enclosure
SUMMARY OF FINDINGS
IR 05000443/2015007; 3/2/2015 - 3/19/2015; Seabrook Station, Unit No. 1; Permanent Plant
Modifications Engineering Team Inspection.
This report covers a 2 week on-site inspection of the evaluations of changes, tests, and experiments and permanent plant modifications. The inspection was conducted by three region-based engineering inspectors. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process,
Revision 5.
No findings were identified.
ii
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R17 Evaluations of Changes, Tests, and Experiments and Permanent Plant Modifications
.1 Evaluations of Changes, Tests, and Experiments (23 samples)
a. Inspection Scope
The team reviewed six safety evaluations to evaluate whether the changes to the facility or procedures, as described in the Updated Final Safety Analysis Report (UFSAR), had been reviewed and documented in accordance Title 10 of the Code of Federal Regulations (10 CFR) 50.59 requirements. In addition, the team evaluated whether NextEra had been required to obtain U.S. Nuclear Regulatory Commission (NRC) approval prior to implementing the changes. The team interviewed plant staff and reviewed supporting information including calculations, analyses, design change documentation, procedures, the UFSAR, Technical Specifications, and plant drawings to assess the adequacy of the safety evaluations. The team compared the safety evaluations and supporting documents to the guidance and methods provided in Nuclear Energy Institute (NEI) 96-07, Guidelines for 10 CFR 50.59 Evaluations, Revision 1, as endorsed by NRC Regulatory Guide 1.187, Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments, to determine the adequacy of the safety evaluations.
The team also reviewed a sample of seventeen 10 CFR 50.59 screenings for which NextEra had concluded that a safety evaluation was not required. These reviews were performed to assess whether NextEra's threshold for performing safety evaluations was consistent with 10 CFR 50.59. The sample included design changes, calculations, and procedure changes.
The team reviewed the safety evaluations and screenings that NextEra had performed and approved during the time period covered by this inspection not previously reviewed by NRC inspectors. The samples selected were based on the safety significance, risk significance, and complexity of the change to the facility.
In addition, the team compared NextEras administrative procedures used to control the screening, preparation, review, and approval of safety evaluations to the guidance in NEI 96-07 to evaluate whether the procedures adequately implemented the requirements of 10 CFR 50.59. The reviewed safety evaluations and screenings are listed in the
.
b. Findings
No findings were identified.
.2 Permanent Plant Modifications (10 samples)
.2.1 Installation of Oil Sample Ports on the A and B Containment Building Spray Pump and Motor
Bearings
a. Inspection Scope
The team reviewed engineering change (EC) 144978 which installed oil sample ports on the containment building spray (CBS) pump and motor bearings. NextEra performed the modification to provide more effective oil sampling through the collection of a representative and repeatable sample to determine oil and component condition. The modification affected eight locations, two on each CBS pump and two on each CBS motor.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the CBS system had been degraded by the modification. The team interviewed design engineers and reviewed design drawings and calculations to determine if the new oil sample ports and installed configuration met design and licensing requirements. The team reviewed post maintenance test (PMT) results and associated maintenance work orders to determine if NextEra appropriately implemented the modification. The team also reviewed CBS pump and motor oil analysis reports, trend data, and the CBS system health report to assess the oil and bearing conditions. The team performed several walkdowns of all eight CBS oil sample ports to verify that NextEra had adequately implemented the modification, maintained configuration control, and had not impacted the function of other safety-related structures, systems, and components (SSC)located in the vicinity. The team also reviewed corrective action condition reports (CR) and the CBS system health report to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.2 Service Water Piping Replacement for the Diesel Generator and Primary Component
Cooling Water Heat Exchangers
a. Inspection Scope
The team reviewed EC 274172 which replaced degraded Plastisol-lined service water (SW)piping on the supply and return of the A and B emergency diesel generator (EDG) heat exchangers and degraded cement-lined SW piping on the supply side of the A primary component cooling water (PCCW) heat exchanger. NextEra performed the modification to replace degraded SW piping with a corrosion resistant material to ensure long-term system pressure boundary integrity. NextEra replaced the carbon steel lined piping with AL-6XN, an austenitic stainless steel material, suitable for seawater service without the need for internal lining or protective coating.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the EDG, PCCW, and SW systems had been degraded by the modification. The team interviewed design engineers and reviewed design drawings and calculations to determine if the new SW piping met design and licensing requirements.
Additionally, the team reviewed non-destructive examination (NDE) results and associated maintenance work orders to determine if NextEra appropriately implemented the modification. The team performed several walkdowns of the accessible portions of the replaced SW piping, including a walkdown during a prolonged A EDG run on March 5, 2015, to verify that NextEra had adequately implemented the modification, maintained pressure boundary integrity and configuration control, and had not impacted the function of other safety-related SSCs located in the vicinity. The team also reviewed corrective action CRs and the EDG, PCCW, and SW system health reports to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.3 Diesel Generator Turbocharger Jacket Cooling Water Outlet Piping Replacement
a. Inspection Scope
The team reviewed EC 274318 which replaced the majority of the turbocharger small-bore jacket water (JW) outlet piping on the A EDG. NextEra performed the modification to eliminate four of the six non-standard piping flanges, and to replace all of the DURLON 8500 gasket material installed in October 2003. Industry operating experience (OE) from Callaway Nuclear Station indicated that the gasket material installed in 2003 was susceptible to age-related failure. Callaway had experienced a leak from a 2-bolt rectangular flange on their EDG turbocharger JW outlet piping that resulted in unplanned EDG unavailability. In addition to replacing all of the susceptible gasket material, the Seabrook modification included fabricating new 8-bolt plates for the turbocharger casing. NextEra machined the new plates with socket weld fittings which allowed welding of the piping directly to the plate. For the remaining two 2-bolt flanges, NextEra installed new gaskets, new higher torque bolting, and locking devices.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the EDGs JW cooling system had been degraded by the modification. The team interviewed design engineers and reviewed design drawings and calculations to determine if the new piping and flanges met design and licensing requirements. Additionally, the team reviewed NDE results and associated maintenance work orders to determine if NextEra appropriately implemented the modification. The team performed several walkdowns of the accessible portions of the replaced JW piping and the JW expansion tanks, including a walkdown during a prolonged A EDG run on March 5, 2015, to verify that NextEra had adequately implemented the modification, maintained pressure boundary integrity and configuration control, and had not impacted the function of other safety-related EDG components located in the vicinity. The team also reviewed corrective action CRs and the EDG system health report to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.4 Chemical and Volume Control System Control Valve Air Supply Modification
a. Inspection Scope
The team reviewed EC 270448 which modified the airline piping material for two air-operated valves (AOV) 1-CS-HCV-182 and 1-CS-FCV-121) in the chemical and volume control system (CVCS). NextEra performed the modification in response to a sheared airline caused by the use of improperly annealed red brass piping. NextEra implemented the modification to upgrade the material for the piping and selected fittings to stainless steel to provide a more robust and reliable piping configuration. Valve 1-CS-HCV-182 is an air-operated, fail-open, modulating control valve. Its design function is to control and direct charging pump flow to the reactor coolant system (RCS) loops via the normal charging path.
By controlling the charging path flow, the reactor coolant pump (RCP) seal injection flow is also controlled. Valve 1-CS-FCV-121 is an air-operated, fail-open, modulating control valve. It is used to control the charging flow rate to the RCS when either of the centrifugal charging pumps is used for normal charging operations.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the CVCS system had been degraded by the modification. The team interviewed design engineers and reviewed design drawings and airline specifications to determine if the new piping and fittings met design and licensing requirements.
Additionally, the team reviewed PMT results and associated maintenance work orders to determine if NextEra appropriately implemented the modification. The team performed walkdowns of both AOVs to verify that NextEra had adequately implemented the modification, maintained configuration control, and had not impacted the function of other safety-related SSCs located in the vicinity. The team also reviewed corrective action CRs and the CVCS and plant air system health reports to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.5 Diesel Generator Cooling Water Header O-Ring Material Substitution
a. Inspection Scope
The team reviewed EC 274150 which evaluated and approved a material substitution for the O-rings installed in the cylinder JW headers on the EDGs. NextEra performed the modification because the diesel engine original equipment manufacturer (OEM)recommended the substitute material (Viton) for the EDG cooling water system application.
The O-rings, which are installed in the mechanical joints of the JW supply and return headers, provide a soft sealing element to prevent fluid leakage. The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the EDGs JW cooling system had been degraded by the modification.
The team interviewed design engineers and reviewed design drawings and material specifications to determine if the new O-rings met design and licensing requirements.
Additionally, the team reviewed a sample of EDG surveillances, including a 24-hour loaded run on the A EDG, and associated maintenance work orders that installed the new O-rings to determine if NextEra appropriately implemented the modification and to assess the leak tightness of the JW piping mechanical joints. The team performed several walkdowns of the accessible portions of the JW supply and return header mechanical joints and the JW expansion tanks, including a walkdown during a prolonged A EDG run on March 5, 2015, to verify that NextEra had adequately implemented the modification, minimized JW leakage, and properly maintained JW system inventory. The team also reviewed corrective action CRs and the EDG system health report to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.6 Replacement of 1-CBS-V-2 Motor Operator
a. Inspection Scope
The team reviewed modification EC 272397 that replaced the motor for motor-operated valve (MOV) 1-CBS-V-2, which is a containment building spray suction valve from the refueling water storage tank. The motors existing magnesium rotor was replaced with an aluminum rotor to address an industry operating experience concern where oxidation and corrosion of the magnesium rotor components resulted from exposure to high humidity and temperatures.
The team reviewed the modification to evaluate whether NextEras analysis of the change was adequate to maintain the design bases, licensing bases, and design margins of the MOV. The team verified that NextEra properly translated design inputs into the associated design bases and procedures. The team also reviewed the PMT and performed a walkdown of the MOV and adjacent equipment to assess whether NextEra adequately maintained configuration control. The team reviewed associated CRs to assess NextEra's ability to evaluate and correct problems. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.7 Revise Emergency Feedwater High Flow Isolation Setpoint
a. Inspection Scope
The team reviewed modification EC 274551 that increased the emergency feedwater (EFW)high flow isolation setpoint to ensure that two intact steam generators would be available with a single failure following a postulated faulted steam generator condition. NextEra determined that this modification was necessary following a plant transient in 2008 (plant trip due to 345 kV bus fault) in which EFW flow was automatically isolated from two steam generators due to high EFW flow. NextEra determined that increasing the high flow isolation setpoint would provide additional margin to reaching the high flow trip while maintaining the design and licensing bases intact.
The team reviewed the modification to determine if the design bases, licensing bases, and performance capability of the EFW system had been degraded by the high flow isolation setpoint modification. The team reviewed calculations, drawings, and procedures to verify that the EFW system would function in accordance with design assumptions. The team reviewed the associated work order instructions, PMT results, and other documentation to verify that the modification was implemented as designed. The team also performed walkdowns of accessible portions of the EFW system to verify that NextEra had maintained configuration control and to assess the material condition of affected components.
Additionally, the team reviewed corrective action reports to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.8 Valve Modifications to Prevent Pressure Locking for 1-SI-V-138 and 1-SI-V-139
a. Inspection Scope
The team reviewed modification EC 275419 that provided a vent path from the bonnet cavity of high head safety injection valves 1-SI-V-138 and 1-SI-V-139 (parallel cold leg injection valves). This modification was necessitated by reduced margin for overcoming the calculated loads associated with pressure locking. Although the valves remained capable of performing their design functions under postulated conditions, this modification improved the operating margin.
The team reviewed the modification to determine if the design bases, licensing bases, and performance capability of the high head safety injection system had been degraded by the valve modification. The team reviewed calculations, drawings, and procedures to verify that the safety injection system would function in accordance with design assumptions. The team reviewed the associated work order instructions, PMT results, and other documentation to verify that the modification was implemented as designed. The team also performed walkdowns of accessible portions of the modified valves and associated accessible equipment to verify that NextEra had maintained configuration control and to assess the material condition of affected components. Additionally, the team reviewed corrective action reports to determine if there were reliability or performance issues that may have resulted from the modification. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.9 Seabrook Substation Reliability Upgrade Project
a. Inspection Scope
The team reviewed modification EC 145280 that upgraded several breakers in the Seabrook substation and redesigned the substation layout to improve reliability. The upgraded substation added three new breakers and replaced two of the original breakers.
The new configuration addresses breaker obsolescence and provides dedicated breakers for the reserve auxiliary transformers and generator step-up transformer. This configuration improves the redundancy for power sources during offsite line losses and outages.
The team reviewed the modification to determine if the design basis, licensing basis, and performance capability of the substation had been degraded by the modification. The team reviewed the completed work order and documentation to verify that the modification was installed as designed and the team reviewed the associated PMT results to ensure that NextEra specified appropriate tests and acceptance criteria, and that the test results confirmed satisfactory performance. Additionally, the team interviewed design engineers and reviewed CRs to determine if the modification corrected performance issues associated with substation reliability and to determine if there were reliability or performance issues created from the modification. The team also reviewed affected drawings and maintenance procedures to ensure that they were properly updated and walked down the substation to assess the material condition and configuration. Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.10 1-SW-V-4 Running Current Change
a. Inspection Scope
The team reviewed modification EC 277469 that adjusted the thermal overload (TOL)setpoint for 1-SW-V-4, which is an MOV credited with isolating safety-related portions of the service water system from non-safety portions of the system. When MOVs are initially installed at Seabrook, their TOL is set based upon the initial full load amps (FLA) for the motor. After maintenance is performed on the motors, the valves occasionally draw more current than the initial FLA. With an increase in current, there is a potential for inadvertently tripping the TOL. 1-SW-V-4 was found to draw more current than the initial FLA so the associated TOL setting was increased to prevent spurious tripping.
The team reviewed the modification to determine if the design basis, licensing basis, and performance capability of the MOV, associated motor control center, and associated EDG had been degraded by the modification. The team reviewed the completed work order and documentation to verify that the modification was installed as designed and the team reviewed the associated PMT results to ensure that NextEra specified appropriate tests and acceptance criteria, and that the test results confirmed satisfactory performance.
Additionally, the team interviewed design engineers and reviewed CRs to determine if the modification corrected the inadequate TOL sizing and to determine if there were reliability or performance issues created from the modification. The team also reviewed affected calculations and maintenance procedures to ensure that they were properly update.
Additionally, the team reviewed the 10 CFR 50.59 screen and engineering evaluation associated with this modification. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA2 Identification and Resolution of Problems (IP 71152)
a. Inspection Scope
The team reviewed a sample of CRs associated with 10 CFR 50.59 and plant modification issues to evaluate whether NextEra was appropriately identifying, characterizing, and correcting problems associated with these areas, and whether the planned or completed corrective actions were appropriate. In addition, the team reviewed CRs written on issues identified during the inspection to verify NextEra adequately described the problem and incorporated the issue into their corrective action system. The CRs reviewed are listed in the Attachment.
b. Findings
No findings were identified.
4OA6 Meetings, including Exit
The team presented the inspection results to Mr. Dean Curtland, Site Vice President, and other members of the Seabrook Station staff at an exit meeting on March 19, 2015. The team returned the proprietary information reviewed during the inspection and verified that this report does not contain proprietary information.
ATTACHMENT
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- D. Curtland, Site Vice President
- V. Brown, Senior Licensing Engineer
- R. Dean, Principal Engineer
- T. Glowacky, Principal Engineer
- K. Harper, System Engineer (Charging System)
- B. Matte, Electrical Design Engineer
- D. McGonigle, Jr., Design Engineering Supervisor
- V. Patel, Senior Engineer
- N. Pietrantonio, Mechanical Design Engineer
- J. Sweeney, Principal Engineer
- C. Thomas, Mechanical Design Engineer
LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED
Open and
Closed
None