IR 05000277/2016007

Evaluation of Changes, Tests and Experiments and Permanent Modifications Team IR 05000277-2016007 and 05000278-2016007

ML16074A290
Person / Time
Site:	Peach Bottom
Issue date:	03/14/2016
From:	Halter M Engineering Region 1 Branch 2
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Halter M
References
Download: ML16074A290 (22)

Text

rch 14, 2016

SUBJECT:

PEACH BOTTOM ATOMIC POWER STATION - EVALUATION OF CHANGES, TESTS, AND EXPERIMENTS AND PERMANENT MODIFICATIONS TEAM INSPECTION REPORT 05000277/2016007AND 05000278/2016007

Dear Mr. Hanson:

On February 12, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The enclosed inspection report documents the inspection results, which were discussed on February 12, 2016, with Mr. Michael Massaro, Peach Bottom Site Vice President, 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 this inspection, no findings were identified.

In accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of the NRC's Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRCs Website at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Mandy K. Halter, Chief Engineering Branch 2 Division of Reactor Safety Docket Nos. 50-277 and 50-278 License Nos. DPR-44 and DPR-56

Enclosure:

Inspection Report 05000277/2016007 and 05000278/2016007 w/Attachment: Supplemental Information

REGION I==

Docket Nos.: 50-277 and 50-278 License Nos.: DPR-44 and DPR-56 Report Nos.: 05000277/2016007 and 05000278/2016007 Licensee: Exelon Generation Company, LLC Facility: Peach Bottom Atomic Power Station, Units 2 and 3 Location: Delta, Pennsylvania Inspection Period: January 25, 2016 through February 12, 2016 Inspectors: J. Ayala, Reactor Inspector, Division of Reactor Safety (DRS)

Team Leader K. Mangan, Senior Reactor Inspector, DRS J. Schoppy, Senior Reactor Inspector, DRS Approved By: Mandy K. Halter, Chief Engineering Branch 2 Division of Reactor Safety Enclosure

SUMMARY

IR 05000277/2016007 and 05000278/2016007; 01/25/16 - 02/12/16; Peach Bottom Atomic

Power Station (PBAPS), Units 2 and 3; Engineering Specialist Plant Modifications Inspection.

This report covers a two week inspection of the evaluations of changes, tests, or 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, dated February 2014.

No findings were identified.

REPORT DETAILS

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R17 Evaluations of Changes, Tests, or Experiments and Permanent Plant Modifications

(IP 71111.17)

.1 Evaluations of Changes, Tests, or Experiments (27 samples)

a. Inspection Scope

The team reviewed nine 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 Exelon 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 (TS), 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 eighteen 10 CFR 50.59 screenings and applicability determinations for which Exelon had concluded that no safety evaluation was required.

These reviews were performed to assess whether Exelons threshold for performing safety evaluations was consistent with 10 CFR 50.59. The sample included design changes, calculations, procedure changes, and setpoint changes. The screenings and applicability determinations were selected based on the safety significance, risk significance, and complexity of the change to the facility.

In addition, the team compared Exelons administrative procedures used to control the screening, preparation, review, and approval of safety evaluations to the guidance in NEI 96-07 to determine whether those procedures adequately implemented the requirements of 10 CFR 50.59. The reviewed safety evaluations, screenings, and applicability determinations are listed in the attachment.

b. Findings

No findings were identified.

.2.1 Unit 3 High Pressure Service Water Pump Motor Oil Coolers Replacement

a. Inspection Scope

The team reviewed modification ECP-14-00317 that replaced the Unit 3 high pressure service water pump (HPSW) motor oil coolers. Based on Peach Bottom Unit 2 HPSW system operating experience, engineering recommended a proactive replacement of the HPSW pump motor oil cooler cooling coils. Engineering determined that corrosion had caused a cooling coil leak on the 2B HPSW pump motor in October 2013 and developed the modification to replace the pre-existing copper cooling coils with upgraded stainless equivalent cooling coils. At the time of the inspection, Exelon had implemented the modification on three of the four Unit 3 HPSW pumps and planned to install the upgraded motor oil cooler in the 3D HPSW pump motor in the Fall 2016.

The team reviewed the modification to verify that the design bases, licensing bases, and performance capability of the HPSW system had not been adversely impacted by the modification. The team interviewed engineering staff and reviewed technical evaluations associated with the modification to determine if the HPSW pump motors would function in accordance with the design assumptions. The team reviewed the associated maintenance work orders to determine if Exelon appropriately implemented the modification. The team performed several walkdowns of the accessible portions of the HPSW pump motor cooling water supply and return piping and components to independently assess Exelons configuration control, the operating environment, and the material condition of the associated structures, systems, and components (SSCs). On January 26, 2016, the team observed portions of a prolonged run on the 3B HPSW pump to independently assess pump performance, cooling system integrity, and cooling coil flow. The team reviewed the associated post maintenance test (PMT) results, recent oil sample analyses, system health reports, and recent surveillance test results to verify that the HPSW pumps functioned as designed following the modification. The team also reviewed corrective action issue reports (IRs) to determine if there were reliability or performance issues that may have resulted from the modification. The documents reviewed are listed in the attachment.

b. Findings

No findings were identified.

.2.2 Emergency Service Water Pipe Replacement

a. Inspection Scope

The team reviewed modification ECP-11-00335 that replaced a portion of the 6 emergency service water (ESW) supply piping to the E4 emergency diesel generator (EDG). Exelon replaced the ESW piping to address corrosion and wall thinning concerns. The modification also approved the use of slip-on flanges to aid in the piping replacement.

The team reviewed the modification to verify that the design bases, licensing bases, and structural integrity of the ESW piping and supports had not been degraded by the modification. The team interviewed design engineers, and reviewed evaluations, pipe stress calculations, surveillance and non-destructive examination (NDE) results, and associated maintenance work orders to verify that Exelon appropriately implemented the ESW piping replacement and maintained the ESW piping in accordance with design assumptions. The team also performed several walkdowns of the accessible portions of the ESW system to ensure that the system configuration was in accordance with design instructions and that ESW piping integrity was maintained. The team also reviewed corrective action IRs and the ESW system health report to determine if there were reliability or performance issues that may have resulted from the modification. The documents reviewed are listed in the attachment.

b. Findings

No findings were identified.

.2.3 Unit 3 High Pressure Service Water Cross Tie Modification

a. Inspection Scope

The team reviewed modification DCP-13-00133 that implemented physical changes to the Unit 3 HPSW cross tie motor-operated valve (MOV MO-3-32-3344) and associated discharge piping. This included replacing the MOV with a normally closed butterfly valve equipped with a motor operator sized to permit stroking of the MOV, when starting a second HPSW pump to deliver HPSW cooling water flow through a second RHR HX, to meet the extended power uprate (EPU) heat removal requirements.

The team reviewed the modification to verify that the design bases and licensing bases and performance capability of the HPSW system had not been degraded by the modification. The team interviewed design engineers, and reviewed calculations, evaluations, PMT results, and associated maintenance work orders to verify that Exelon implemented the modification as designed. The team also performed several walkdowns of the cross tie MOV and associated HPSW discharge piping in the Unit 3 HPSW pump room to ensure that the system configuration was in accordance with design instructions, the HPSW system integrity was maintained, and that important to safety SSCs in the vicinity were not adversely impacted. The team also reviewed corrective action IRs and system health reports to determine if there were reliability or performance issues that may have resulted from the modification. The documents reviewed are listed in the attachment.

b. Findings

No findings were identified.

.2.4 Core Spray Torus Pump Suction Isolation Valve MO-2-14-070 Torque Switch Bypass

a. Inspection Scope

The team reviewed ECR-13-00235 that electrically bypassed the torque switch in motor operated valve (MOV) operator MO-2-14-070. Valve MO-2-14-070 is the Core Spray (CS) torus water filter pump suction isolation valve. The valve is normally closed and performs an active safety function to automatically close, if in the open position, upon initiation of a loss of coolant accident (LOCA) to provide primary containment isolation by isolating the torus water clean-up from suppression pool inventory. The closure prevents inadvertent draining of the suppression pool inventory. Exelon implemented the modification to ensure the valve goes closed and eliminate the possibility of the valve stroke stopping in an intermediate position.

The team reviewed the modification to verify that the design bases, licensing bases and performance capability of the CS system had not been degraded by the modification.

The team interviewed design engineers, and reviewed evaluations, MOV calculations, surveillance results, and associated maintenance work orders to verify that Exelon appropriately implemented the modification in accordance with design assumptions.

The team also performed several walkdowns of the accessible portions of CS system to independently assess Exelons configuration control and the material condition of the CS system. The team also reviewed corrective action IRs to determine if there were reliability or performance issues that may have resulted from the modification. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

.2.5 PB 13-00433, Core Spray In-Vessel Pipe Replacement

a. Inspection Scope

The team reviewed modification ECR-13-00433 which replaced piping, supports, and mechanical joint connections inside the reactor vessel for the core spray system. The modification was performed to address degradation identified in welded sections of the piping due to intergranular stress corrosion cracking (IGSCC). The replacement piping and sleeve assemblies were constructed with material that is resistant to IGSCC.

The team reviewed the modification to determine if the design, licensing bases, and performance capability of the core spray system had been degraded by the modification.

The team reviewed calculations, licensee design documents, and associated maintenance work orders to determine if the changes were appropriately implemented.

The team also reviewed corrective action IRs to determine if there were reliability or performance issues that may have resulted from the modification.

Finally, the team interviewed design engineers to determine if the changes met design and licensing requirements. The 10 CFR 50.59 screening determination associated with this modification was reviewed as described in Section 1R17.1 of this report.

Documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

.2.6 PB 13-00132, EPU HPSW Mod - AC Mechanical

a. Inspection Scope

The team reviewed modification ECR 13-00132 which installed manual isolation valves on a new section of HPSW piping. This modification, along with several other modifications, was performed to allow for the connection of separate trains of high pressure service water (HPSW), if needed during an event, and thereby improve the flexibility of the HPSW and residual heat removal (RHR) systems to reduce overall risk to the plant. These valves were installed to provide capability to isolate the motor operated cross connect valve for maintenance.

The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the HPSW or RHR system had been degraded by the modifications. The team interviewed design engineers and reviewed the replacement valve design to determine if the changes were consistent with the design and licensing requirements. Additionally, the team reviewed post maintenance test (PMT) results, and associated maintenance work orders to determine if the changes were appropriately implemented and tested, in accordance with American Society of Mechanical Engineers (ASME) Code requirements. The team also performed a walkdown of the valves to assess the overall material conditions of the valves, associated piping, and supports following the modification work. Documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

2.7 PB 13-00060, Change RCIC TDH for 3% SV/SRV Tolerance Project

a. Inspection Scope

The team reviewed modification ECR 13-00060 which was performed to evaluate the impact of expanding the allowed safety relief valve operating set point tolerance range from (+/-) 1 percent to (+/-) 3 percent on the operation of the reactor core isolation cooling (RCIC) system. The modification developed a flow model for the RCIC system and evaluated if design flow rates would be available at maximum reactor pressure and minimum system supply pressure. This analysis verified that if the valve did not open until reactor pressure was 103% of the safety relief valve set pressure, adequate flow, as described in the design basis of the RCIC system, would be achieved.

The team reviewed the analysis to evaluate whether the design inputs and outputs were technically reasonable. Additionally, the team reviewed calculation results to determine whether the design bases, licensing bases, and performance capability of RCIC system had been degraded by the modification. Specifically, the team evaluated whether the increased reactor pressure adversely affected flowrates when the RCIC pump suction was aligned to the torus. Finally, the team interviewed design engineers to determine the bases for assumptions in the calculations. The 10 CFR 50.59 process applicability determination associated with this EC was also reviewed as described in Section 1R17.1 of this report. Documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

2.8 Add Safety Related Closed Function to RCIC Turbine Trip Valves

a. Inspection Scope

The team reviewed modification ECR-13-00094 which added a safety related close function to the normally open Reactor Core Isolation Cooling (RCIC) turbine trip throttle valve. The modification was performed to address the potential for a water hammer event identified through external operating experience (OE). The OE described the potential for water hammer during performance of vacuum breaker maintenance while maintaining RCIC operable. The trip throttle valve, which is a spring-to close-valve, must close with a faster stroke time than the vacuum breaker isolation valve in order to minimize the potential for water hammer. The modification was performed to ensure that the trip throttle valve closes before the vacuum breaker isolation valve.

The team reviewed the modification to determine if the design, licensing bases, and performance capability of the RCIC system had been degraded by the modification.

The team interviewed design engineers, and reviewed evaluations, surveillance results, and associated maintenance work orders to verify that Exelon appropriately, implemented the modification in accordance with design assumptions. The team also performed several walkdowns of the accessible portions of RCIC system to independently assess Exelons configuration control and the material condition of the RCIC system. The team also reviewed corrective action IRs and to determine if there were reliability or performance issues that may have resulted from the modification. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

2.9 FLEX Modification - Units 2 and 3 Diesel Fuel Oil Supply

a. Inspection Scope

The team reviewed modification ECR-13-0279 which installed piping, valves, and quick-connect coupling onto the auxiliary boiler diesel fuel oil system to support diesel-driven FLEX equipment during FLEX coping strategies. The modification was performed as a result of NRC Order EA-12-049, Order Modifying License with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events.

The team reviewed the modification to determine if the design, licensing bases, and performance capability of the EDG system had been degraded by the modification.

The team reviewed the evaluation and associated maintenance work orders to verify that Exelon appropriately implemented the modification in accordance with design assumptions. The team also reviewed corrective action IRs and to determine if there were reliability or performance issues that may have resulted from the modification. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.

b. Findings

No findings were identified.

4OA2 Identification and Resolution of Problems (IP 71152)

a. Inspection Scope

The team reviewed a sample of problems that Exelon had previously identified and entered into the corrective action program. The team reviewed these issues to verify an appropriate threshold for identifying issues and to evaluate the effectiveness of corrective actions. In addition, the team reviewed corrective action IRs written on issues identified during the inspection to verify adequate problem identification and incorporation of the problem into the corrective action system. The specific corrective action documents that were sampled and reviewed by the team are listed in the attachment.

b. Findings

No findings were identified.

4OA5 Other Activities

In addition to the samples documented in this report, three additional samples were completed within the scope of this inspection procedure and documented in Section1R17 of Inspection Report 05000277/2015002 and 05000278/2015002 (ML15215A527), dated August 3, 2015. One safety evaluation, PB-2013-002-E, EPU App R/SBO Mod - CST Standpipe, one modification ECR-12-00155, Unit 2 EPU HPSW Mod - Electrical Scope, Revision 4, and ECR-13-00135, Unit 2 EPU HPSW Mod - Mechanical Scope, and one screening PB-2014-021-S, Unit 2 - HPSW Cross-Tie Modification, are documented in the referenced report.

4OA6 Meetings, including Exit

The team presented the inspection results to Mr. Mike Massaro, Site Vice President, and other members of Exelons staff at an exit meeting on February 12, 2016. The team returned the proprietary information reviewed during the inspection to the licensee and verified that this report does not contain proprietary information.

ATTACHMENT

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Exelon Personnel

M. Massaro, Site Vice President

P. Navin, Plant Manager

T. Dombach, Electrical Design Engineer

D. Dullum, Regulatory Assurance Engineer

D. Knepper, Senior Design Engineer

J. Mann, Design Engineer

J. Armstrong, Regulatory Assurance Manager

J. Phipps, Supervisor, Mechanical Maintenance Team 5

NRC Personnel

J. Heinly, Senior Resident Inspector

B. Smith, Resident Inspector

ITEMS OPENED, CLOSED AND DISCUSSED

None