IR 05000219/2010008

IR 05000219-10-008, on 08/03/2010 - 08/27/2010; Exelon Energy Company, LLC, Oyster Creek Generating Station; Component Design Bases Inspection

ML102800368
Person / Time
Site:	Oyster Creek
Issue date:	10/07/2010
From:	Doerflein L Engineering Region 1 Branch 2
To:	Pacilio M Exelon Generation Co, Exelon Nuclear
References
IR-10-008
Download: ML102800368 (39)

Text

UNITED STATES ber 7, 2010

SUBJECT:

OYSTER CREEK GENERATING STATION - NRC COMPONENT DESIGN BASES INSPECTION REPORT 05000219/2010008

Dear Mr. Pacilio:

On August 27,2010, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Oyster Creek Generation Station. The enclosed inspection report documents the inspection results, which were discussed on August 27,2010, with Mr. M. Massaro, 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 Commission's rules and regulations and with the conditions of your license.

In conducting the inspection, the team examined the adequacy of selected components and operator actions to mitigate postulated transients, initiating events, and design basis accidents.

The inspection involved field walkdowns, examination of selected procedures, calculations and records, and interviews with station personnel.

This report documents four NRC-identified findings that were of very low safety significance (Green). All of the findings were determined to involve a violation of NRC requirements.

However, because of the very low safety significance of the violations and because they were entered into your corrective action program, the NRC is treating these violations as non-cited violations (NCV) consistent with Section 2.3.2 of the NRC Enforcement Policy. If you contest any NCV in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555-0001, with copies to the Regional Administrator, Region I; the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555-0001; and the NRC Resident Inspector at the Oyster Creek Generating Station. In addition, if you disagree with the cross-cutting aspect assigned to any finding in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region I and the NRC Resident Inspector at the Oyster Creek Generating Station. In accordance with 10 CFR 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 the public inspection in the NRC Public Docket Room or from the Publicly Available Records component of NRC's 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,

~~f)~uu---

Lawrence T. Doerflein, Chief Engineering Branch 2 Division of Reactor Safety Docket No. 50-219 License No. DPR-16

Enclosure:

Inspection Report 05000219/2010008 w/Attachment: Supplemental Information

REGION I==

Docket No.: 50-219 License No.: DPR-16 Report No.: 05000219/2010008 Licensee: Exelon Nuclear Facility: Oyster Creek Generating Station Location: Forked River, New Jersey Dates: August 3,2010 - August 27,2010 Inspectors: F. Arner, Senior Reactor Inspector, Division of Reactor Safety (DRS),

Team Leader J. Schoppy, Senior Reactor Inspector, DRS C. Cahill, Senior Reactor Analyst, DRS P. McKenna, Reactor Inspector, DRS A. Dugandzic, Reactor Inspector (In-Training), DRS S. Spiegelman, NRC Mechanical Contractor S. Kobylarz, NRC Electrical Contractor Approved by: Lawrence T. Doerflein, Chief Engineering Branch 2 Division of Reactor Safety Enclosure

SUMMARY OF FINDINGS

IR 05000219/2010008; 08/03/2010 - 08/27/2010; Exelon Energy Company, LLC, Oyster Creek

Generating Station; Component Design Bases Inspection.

The report covers the Component Design Bases Inspection conducted by a team of five NRC inspectors and two NRC contractors. Four findings of very low risk significance (Green) were identified, all of which were considered to be non-cited violations. The significance of most findings is indicated by their color (Green, White, Yellow, Red) using NRC Inspection Manual Chapter (IMC) 0609, "Significance Determination Process" (SOP). Cross-cutting aspects associated with findings are determined using IMC 0310, "Components Within the Cross-Cutting Areas." Findings for which the SOP does not apply may be Green or be assigned a severity level after NRC management review. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, "Reactor Oversight Process," Revision 4, dated December 200

Cornerstone: Mitigating Systems

• Green: The team identified a finding of very low safety significance (Green) involving a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions,

Procedures, and Drawings, because Exelon did not properly implement scaffolding control procedural requirements. Specifically, Exelon did not perform engineering evaluations for scaffolding constructed within the minimum allowed distance of safety-related equipment to determine its acceptability. Exelon entered the issue into their corrective action system and remediated each identified scaffold issue in accordance with procedural requirements.

The finding was more than minor because it was associated with the external factors attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. In accordance with IMC 0609,

Significance Determination Process, Attachment 0609.04, Phase 1 -Initial Screening and Characterization of Findings, the finding was determined to be of very low safety significance because it was not a design or qualification deficiency, did not represent a loss of a systemltrain safety function, and did not screen as potentially risk significant due to external events. The performance deficiency had a cross-cutting aspect in the area of human performance, Work Practices, because Exelon had not effectively communicated expectations regarding procedural compliance. Specifically, Exelon had not followed procedures and obtained engineering evaluations for scaffolds that did not meet the requirements contained in procedures for scaffold installation in the plant. [IMC 0310, Aspect H.4(b) (Section 1R21.2.1.6)

• Green: The team identified a finding of very low safety significance (Green) involving an NCVof 10 CFR 50, Appendix B, Criterion III, Design Control. Specifically, Exelon did not maintain safety-related emergency diesel generator (EDG) instrumentation and low voltage control cables in the EDG cable trenches from becoming submerged, which resulted in subjecting the cables to an environment for which they were not qualified.

Exelon entered the issue into their corrective action program and determined that there ii

was no impact to EDG operability based on the observed condition of the cables and no apparent signs of degradation.

The finding was determined to be more than minor because the finding was associated with the Mitigating Systems Cornerstone attribute of equipment performance and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, Exelon did not maintain the cables for the EDG 1 and EDG in an environment for which they were designed when the cables were allowed to be submerged in a below grade trench without ensuring adequate drainage. The team determined the finding could be evaluated using the SDP in accordance with IMC 0609,

Significance Determination Process, Attachment 0609.04, Phase 1 - Initial Screening and Characterization of Findings. The finding was of very low safety significance because it was a qualification deficiency confirmed not to result in a loss of operability.

The performance deficiency had a cross-cutting aspect in the area of human performance, Resources, because Exelon did not ensure that personnel, equipment, procedures, and other resources were available and adequate to maintain long term plant safety through minimization of long-standing equipment issues. Specifically,

Exelon did not correct long-standing deficiencies that allowed debris to block the drains allowing the cables to become submerged. Additionally, procedures were not adequate to ensure that the trenches were inspected and the drains were maintained to ensure that they remained free of debris. [IMC 0310, Aspect H.2.(a)) (Section 1R21.2.1.9)

• Green: The team identified a finding of very low safety significance (Green) involving an NCVof 10 CFR 50, Appendix B, Criterion XI, Test Control, because Exelon had not established a test program for safety-related load center transformer cooling fans to confirm the capability of the fans to cool the load center at its rated output. Specifically,

Exelon had not established periodic testing to verify the 1A2 and 1B2 transformer cooling fans were functional to support the design rating allowed for in operational procedures. This failed to meet the design requirement established in modification package SDD OC-732A, which required in part, that the cooling system fans shall be periodically tested for operability both in the manual and automatic modes. Exelon entered the issue into the corrective action program and tested the fans during the inspection to ensure the fans were operational in the manual mode and would be in a ready to operate status if needed.

The finding was determined to be more than minor because it was associated with the Mitigating Systems Cornerstone attribute of procedure quality and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the lack of testing impacts the objective because there is no method to determine the capability of the fans to support cooling of the transformers at their rated output. The team determined the finding could be evaluated using the SDP in accordance with IMC 0609, Significance Determination Process, Attachment 0609.04, Phase 1-lnitial Screening and Characterization of Findings. The finding was of very low safety significance because it was not a design or qualification deficiency, did not represent a loss of a system/train safety function, and did not screen as potentially risk significant due to external events. The team did not identify a cross-cutting aspect with this finding iii because this was an old design/test issue and therefore was not reflective of current performance. (Section 1R21.2.1.10)

• Green: The team identified a finding of very low safety significance (Green) involving an NCVof 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, because Exelon did not identify and correct a condition adverse to quality. Specifically, Exelon did not identify and correct an impaired ball float drain valve that had the potential to adversely impact two safety-related core spray pumps during an internal flooding event. Exelon's short-term corrective actions included entering the issue into their corrective action program, removing the ball float valve impairment to restore functionality, and improving configuration control awareness.

The finding is more than minor because it is associated with the configuration control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the capability, availability and reliability of systems (core spray pumps) that respond to initiating events to prevent undesirable consequences. In accordance with IMC 0609, Significance Determination Process, Attachment 0609.04,

Phase 1 - Initial Screening and Characterization of Findings, the finding screened as potentially risk significant. After additional SDP Phase 3 analysis, the team determined the finding was of very low safety significance (Green) because flood mitigation that was impacted by the finding would have minimal impact on redundant equipment required to safely shut down the unit. The performance deficiency had a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program Component, because Exelon did not identify issues completely, accurately, and in a timely manner commensurate with their safety significance. Specifically, Exelon did not identify a degraded condition involving a non-functional ball float drain valve. [IMC 0310, Aspect P.1 (a)] (Section 1R21.2.2.2)iv

REPORT DETAILS

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity

1R21 Component Design Bases Inspection (IP 71111.21)

.1 Inspection Sample Selection Process

The team selected risk significant components and operator actions for review using information contained in the Oyster Creek Generating Station Probabilistic Safety Assessment and the U.S. Nuclear Regulatory Commission's (NRC) Standardized Plant Analysis Risk (SPAR) model. Additionally, the Oyster Creek Significance Determination Process (SDP) Phase 2 Notebook (Revision 2.1 a) was referenced in the selection of potential components and operator actions for review. In general, the selection process focused on components and operator actions that had a Risk Achievement Worth (RAW)factor greater than 1.3 or a Risk Reduction Worth (RRW) factor greater than 1.005. The components selected were located within both safety-related and non-safety related systems, and included a variety of components such as pumps, breakers, heat exchangers, transformers, and valves.

The team initially compiled a list of components and operator actions based on the risk factors previously mentioned. Additionally, the team reviewed the previous component design bases inspection report (05000219/2007006) and excluded those components previously inspected. The team then performed a margin assessment to narrow the focus of the inspection to 17 components, four operator actions, and three operating experience items. The team's evaluation of possible low design margin included consideration of original design issues, margin reductions due to modifications, or margin reductions identified as a result of material condition/equipment reliability issues.

The assessment also included items such as failed performance test results, corrective action history, repeated maintenance, maintenance rule (a)(1) status, operability reviews for degraded conditions, NRC resident inspector insights, system health reports, and industry operating experience. Finally, consideration was also given to the uniqueness and complexity of the design and the available defense-in-depth margins. The margin review of operator actions included complexity of the action, time to complete the action, and exlent-of:training on the action.

The inspection performed by the team was conducted as outlined in NRC Inspection Procedure (IP) 71111.21. This inspection effort included walkdowns of selected components, interviews with operators, system engineers and design engineers, and reviews of associated design documents and calculations to assess the adequacy of the components to meet design basis, licensing basis, and risk-informed beyond design basis requirements. Summaries of the reviews performed for each component, operator action, operating experience sample, and the specific inspection findings identified are discussed in the subsequent sections of this report. Documents reviewed for this inspection are listed in the Attachment.

.2.1.1 Outboard B Main Steam Isolation Valve (V-1-10l

a. Inspection Scope

The team inspected the 'B' outboard main steam isolation valve (MSIV) to verify that it was capable of meeting its design basis requirements. The MSIVs are containment isolation valves designed to minimize coolant loss from the vessel and offsite dose in the event of a main steam line break accident. The team reviewed the Updated Final Safety Analysis Report (UFSAR), design basis documents (DBDs), drawings, and procedures to identify the design basis requirements of the MSIVs. The MSIV testing procedures and specifications were reviewed to verify the design basis requirements were appropriately incorporated into the test acceptance criteria and component design. The team reviewed a sample of stroke-time test data and local leak rate test results to verify acceptance criteria were met. The team discussed the design, operation, and corrective maintenance of the MSIV with Exelon's engineering staff to gain an understanding of the performance history and overall component health. Finally, corrective action documents (Issue Reports (IRs)) and system health reports were reviewed to verify deficiencies were appropriately identified and resolved, and that the MSIVs were properly maintained.

b. Findings

No findings were identified .

.2.1.2 Electromatic Relief Valve (V-1-176Dl

a. Inspection Scope

The team inspected electromatic relief valve (EMRV), V-1-176D, to verify it was capable of performing its design basis function. The EMRVs are provided as part of the automatic depressurization system (ADS) to perform a dual function. In the overpressure protection mode, the system is designed to remove sufficient energy from the primary system to prevent the safety valves from opening. The system also acts to automatically depressurize the reactor coolant system in the event of a small-break loss-of-coolant-accident (SBLOCA) to allow the low pressure emergency core cooling system (ECCS) to supply sufficient cooling water to adequately cool the reactor fuel. The EMRVs are pilot-operated to automatically open at a specified reactor pressure. The valves also can be manually operated to perform the depressurization function. The team verified that EMRV opening setpoints were properly calculated and consistent with plant technical specifications (TSs) and system test procedures. The team reviewed the maintenance and in-service test history, IRs, calculations, design specifications, environmental qualification report, and surveillance testing procedures to verify the valve's ability to meet design basis requirements in response to transient and accident events. Finally, the team discussed the deSign, operation, and corrective maintenance of the EMRV with Exelon's engineering staff to gain an understanding of the performance history and overall component health.

b. Findings

No findings were identified.

2.1.3 Standby Liquid Control Pump CP-19-001Al

a. Inspection Scope

The team inspected the "A" standby liquid control (SLC) Pump to verify that it was capable of meeting its design basis requirements. The SLC system is designed to bring the reactor to a shutdown condition at any time in core life independent of control rod capabilities, including anticipated transients without scram (ATWS) events. The team reviewed the UFSAR, design basis documents, drawings, and procedures to identify the most limiting requirements for the SLC pump. The team reviewed a sample of surveillance test results to verify that pump performance met the acceptance criteria.

The team reviewed calculations for net positive suction head (NPSH), discharge piping head loss, and SLC system transport time to ensure that the pump could successfully inject into the reactor vessel consistent with design assumptions for the most limiting A TWS event. The team discussed the design, operation, and corrective maintenance of the SLC pump with engineering staff to gain an understanding of the performance history and overall component health. Additionally, the team also reviewed corrective action documents and system health reports, and performed a walkdown of both SLC pumps to assess the material condition of the equipment.

b. Findings

No findings were identified .

.2.1.4 Containment Spray Motor Operated Valve CV-21-51

a. Inspection Scope

The team inspected the containment spray motor operated valve (MOV), V-21-5, to verify that it was capable of performing its design function. The team reviewed the UFSAR, DBDs, and procedures to identify the design basis requirements of the valve.

The team also reviewed accident system alignments to determine if component operation would be consistent with the design and licensing bases assumptions. Valve testing procedures and valve specifications were also reviewed to ensure consistency with design basis requirements. The team reviewed periodic verification diagnostic test results and stroke test documentation to verify acceptance criteria were met.

Additionally, the team verified the valve safety function was maintained in accordance with Generic Letter (GL) 89-10 guidance by reviewing torque switch settings, performance capability, and design margins. The team reviewed test frequencies to verify they were correctly determined based on test results, as described in GL 96-05.

The team reviewed motor data, degraded voltage conditions, thermal overload settings, and voltage drop calculations to confirm that the MOV would have sufficient voltage and power available to perform its safety function at worst case degraded voltage conditions.

The team interviewed the MOV program engineer to gain an understanding of maintenance issues and overall reliability of the valve. The team also conducted a walkdown to assess the material condition of the valve, and to verify the installed valve configuration was consistent with design basis assumptions and plant drawings. Finally, corrective action documents and system health reports were reviewed to verify that deficiencies were appropriately identified and resolved, and that the valve was properly maintained.

b. Findings

No findings were identified .

.2.1.5 Condensate Storage Tank Hotweilisolation Valve (v-2-90)

a. Inspection Scope

The team inspected the condensate storage tank (CST) isolation valve to the condenser hotwell to verify it could meet its design function. This valve was modified from a manual operated valve to an air-operated valve in 2008 to automatically close the valve upon loss of instrument air during a station blackout (SBO) or fire event. This modification was performed to maintain CST inventory by isolating a potential drain path to the condenser hotwell. The team reviewed the modification to verify that the design basis, licensing basis, and performance capability of the condensate system had not been degraded by the modification. The team reviewed the UFSAR, DBDs, drawings, and procedures to identify the design basis requirements of the isolation valve. Testing procedures and specifications were reviewed to verify the design basis requirements were appropriately incorporated into the test acceptance criteria and component design.

The team discussed the design, operation, and corrective maintenance of the CST isolation valve with engineering staff to gain an understanding of the performance history and overall component health. Finally, corrective action documents and system health reports were reviewed to verify deficiencies were appropriately identified and resolved, and a walkdown of the valve was performed to assess its material condition.

b. Findings

No findings were identified .

.2.1.6 Core Spray Booster Pump (P-20-2Bl

a. Inspection Scope

The team inspected the 'B' core spray booster pump to verify that it was capable of meeting its deSign basis requirements. The team reviewed applicable portions of the UFSAR, DBD, and drawings to identify the design basis requirements for the pump.

The team reviewed calculations and surveillance procedures to verify that the pump was capable of achieving design basis head/flow requirements during worst case design basis conditions and that test acceptance criteria were consistent with these requirements. The team reviewed the hydraulic calculations associated with system flowrate and pressure as well as NPSH for the booster pump to ensure that the design flowrates and pressure could be achieved.

The team interviewed design and system engineers to review the background of the design and system functional requirements as well as historical test performance results.

The team reviewed the maintenance program to ensure critical vendor recommendations were being implemented through periodic maintenance. This included a review of periodic bearing oil test analysis to ensure results were within established acceptance criteria. In addition, the team reviewed work orders and corrective action documents to identify failures or nonconforming issues, and to determine if these deficiencies were being identified and corrected. Finally, the team performed several walkdowns of the core spray system to ensure consistency between the trains and to evaluate the material condition and operating environment of the 'B' core spray booster pump.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green)involving a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, because Exelon did not properly implement scaffolding control procedural requirements. Specifically, Exelon did not perform engineering evaluations for scaffolding constructed within the minimum allowed distance of safety-related equipment to determine its acceptability.

Description:

During a team walkdown of the core spray system trains, the team identified that a scaffold installed in the reactor building deviated from clearance requirements within procedure MA-MA-796-024-1 001, Scaffolding Criteria for the Mid Atlantic Stations, revision 6. The scaffold was installed around the core spray booster pump (P-20-2A). The lateral clearance between the vertical pole and the core spray riser pipe was not within procedural requirements, which required engineering review and approval. During additional walkdowns of plant equipment during the inspection, the team identified other scaffolds which did not meet the procedural requirements for clearance and engineering review and approval. The team noted the following procedural deficiencies with additional scaffolds:

• Scaffold, Tag No. 2010-37 was found with members in contact with the isolation condenser '8' (CD-14-B) pipe insulation. Additionally, the scaffold was not adequately braced internally and externally.

• A scaffold in the northwest core spray pump room was built around the core spray system 1 pump (P-20-1A) piping. The scaffold was not adequately braced and did not meet the clearance requirements for freestanding scaffold in .

accordance with procedure MA-MA-796-024-1001. The deviation had not had engineering review and approval in accordance with procedure requirements.

• A scaffold in the southeast corner room was found to be in contact with the bearing housing of the containment spray pump, 21 D. The scaffold was observed with clearances less than 6 inches to a pipe riser and the overall frame was not externally braced to resist movement.

Exelon reviewed these issues and assessed the potential impact on equipment during a postulated seismic event. In each case it was determined that there would be no adverse impact affecting equipment functionality in response to a seismic event. During the inspection, Exelon suspended all scaffold building at the station to communicate the expectations with future scaffold work and to reinforce procedural compliance expectations. This included reinforcement that engineering must be contacted for direction when it is observed that scaffolds will not meet clearance requirements during installation. Additionally, Exelon remediated each scaffold issue in accordance with procedural requirements.

Analysis:

The performance deficiency associated with this finding involved Exelon not properly implementing scaffolding control requirements contained in procedure MA-MA-796-024-1001. On several occasions Exelon had not performed engineering evaluations for scaffolding constructed within the minimum allowed distance of safety-related equipment to determine its acceptability.

The finding was more than minor because it was associated with the external factors attribute of the mitigating systems cornerstone and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. This finding was also similar to example 4.a in NRC Inspection Manual Chapter (IMC) 0612, "Power Reactor Inspection Reports, Appendix E, Examples of Minor Issues," because Exelon routinely had not performed evaluations for scaffolds constructed within the minimum allowed distance of safety-related equipment. In accordance with IMC 0609, Significance Determination Process, Attachment 0609.04, "Phase 1 - Initial Screening and Characterization of Findings," the finding was determined to be of very low safety significance because it was not a design or qualification deficiency, did not represent a loss of a system/train safety function, and did not screen as potentially risk significant due to external events.

The performance deficiency had a cross-cutting aspect in the area of human performance, Work Practices, because Exelon had not effectively communicated expectations regarding procedural compliance. Specifically, Exelon had not followed procedures and obtained engineering evaluations for scaffolds that did not meet the requirements contained in procedures for scaffold installation in the plant [IMC 0310, Aspect H.4(b).

Enforcement:

10 CFR Part 50, Appendix S, Criterion V, Instructions, Procedures, and Drawings, requires that activities affecting quality shall be prescribed by documented procedures of a type appropriate to the circumstances and shall be accomplished in accordance with these procedures. Exelon's maintenance procedure MA-MA-796-024-1001 is a procedure affecting quality that establishes the minimum clearance between scaffolds and plant equipment. This procedure states, in part, that if a scaffold cannot be built in accordance with guidelines, engineering approval and evaluation shall be obtained. Contrary to the above, prior to August 3, 2010, Exelon had not requested or evaluated several scaffolds constructed within the minimum allowed distance of safety-related equipment. Because this issue is of very low safety significance (Green) and Exelon entered the issue into their corrective action program as IRs 1098064, 1102251, and 1106187, this violation is being treated as an NCV consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000219/2010008-01: Scaffold Installation Procedure Not Properly Implemented)

.2.1.7 Core Spray Pump (P-20-1 B)

a. Inspection Scope

The team inspected the 'B' core spray pump to verify that it was capable of meeting its design basis requirements. The team reviewed applicable portions of the UFSAR, DBD, and drawings to identify the design basis requirements for the pump. The team reviewed calculations and surveillance procedures to verify that the pump was capable of achieving design basis head/flow requirements during worst case design basis conditions and that test acceptance criteria were consistent with these requirements.

The team reviewed the hydraulic calculations associated with system flowrate, pressure, and NPSH to ensure that the design inputs were reasonable.

The team interviewed design and system engineers to review the background of the design and system functional requirements as well as historical test performance results.

The team reviewed the maintenance program to ensure critical vendor recommendations were being implemented through periodic maintenance. This included a review of periodic pump and motor bearing oil test analyses to ensure results were within established acceptance criteria. In addition, the team reviewed work orders and IRs to identify failures or nonconforming issues, and to determine if these deficiencies were being identified and corrected. Finally, the team performed a walkdown of the core spray main pump, motor, and support systems to independently assess Exelon's configuration control, the pump's operating environment, and the pump's material condition.

b. Findings

No findings were identified .

.2.1.8 Emergency Service Water Pump (52A)

a. Inspection Scope

The team inspected the 'A' emergency service water (ESW) pump to verify that it was capable of meeting its design basis requirements. The team reviewed applicable portions of the UFSAR, TSs, and drawings to identify the design basis requirements for the pump. Surveillance tests were reviewed to verify pump performance criteria and performance were consistent with the design basis requirements for flowrate and developed differential pressure.

The team interviewed system engineers to review the background of the design and system functional requirements as well as historical test performance results. The team reviewed work orders and IRs to identify failures or nonconforming issues, and to determine if these deficiencies were being identified and corrected. The team performed a walkdown of the ESW pump, motor, and support systems to independently assess Exelon's configuration control, the pump's operating environment, and the system's material condition. The team observed pump operating parameters during and following two prolonged pump runs when the pump was in-service for torus cooling operations during the inspection period. The team also verified local upper and lower oil bearing temperature indications were within their design parameters.

Findings No findings were identified .

.2.1.9 Emergency Diesel Generator EDG-1

a. Inspection Scope

The team reviewed the one-line diagrams and the vendor nameplate rating data for the emergency diesel generator (EDG) to ensure they were consistent with the design and licensing bases described in the TSs and UFSAR. The team reviewed the EDG loading study to ensure it was consistent with limiting design basis loading conditions under accident conditions. The team reviewed fuel and lube oil availability and quality to ensure test results were consistent with specification design sheets. The team also reviewed TS performance runs to ensure the EDG met all applicable test acceptance criteria. The team conducted walkdowns of the EDGs to determine the material condition and the operating environment for indications of degradation of equipment. In addition, the team reviewed the break horsepower basis for selected pump motors to ensure loads were adequately considered in the loading study and that equipment qualification for selected motors adequately addressed design basis motor load conditions.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green)involving a non-cited violation (NCV) of 10 CFR 50, Appendix S, Criterion III, Design Control. Specifically, Exelon did not maintain safety-related EDG instrumentation and low voltage control cables in the EDG cable trenches from becoming submerged, which resulted in subjecting the cables to an environment for which they were not qualified.

Description:

On August 2, 2010, the team walked down the EDGs to assess their material condition. The team observed that water had accumulated in the cable trenches resulting in low voltage safety-related control power cables being in a submerged condition. This condition existed for both the EDG-1 and EDG-2 trenches.

The drain pit and the cover grate were located inside the north wall of each EDG vault behind the switchgear unit. Exelon determined through further review that there was an accumulation of sand and cement debris covering the drain covers of both EDG cable trench drains and concluded that the water accumulation was due to clogged drains in the sump. The team noted that the EDG building is configured with grating in the roof to accommodate EDG operations. However, these gratings allow rain water to enter the building and the corresponding trenches.

The team noted that several types of cables were determined to be in the trench which were designed for a wet environment but were not qualified for submerged operations.

The team noted that although the trenches were fitted with a drain, it was evident from the water markings on the cables, conduit and trench walls that these safety-related control power cables were submerged routinely. Exelon had previously identified numerous incidents of water intrusion into the building due to its inherent design (IRs 732459, 724535, 811442). This, in addition to other documented housekeeping issues over the last few years (IRs 759449, 786315, 995969, 946686) likely contributed to the clogging of the drains. The team noted that many of these low voltage cables are normally de-energized, but would be energized during a design basis accident and therefore a cable fault may go undetected until the EDG is placed into service. Exelon documented the team's observations in IR 1104875. Exelon completed a visual inspection of the cable trenches and determined that the cable jackets were in good condition with no splices or cracked jackets. During a subsequent de-watering attempt, Exelon found that the drains were clogged with silt/debris. Exelon entered the issue into their corrective action program as IR 1099888 and noted that there were no current effective measures that existed to clean out the trenches or inspect the drains on a regular basis. However, based on the observed condition of the cables and no apparent signs of degradation, Exelon determined that there was no impact to EDG operability.

The team found Exelon's conclusion to be reasonable.

Analysis:

The team determined that the failure to maintain safety-related cables for EDG 1 and EDG 2 in an environment for which they were designed was a performance deficiency. The finding was determined to be more than minor because the finding was associated with the Mitigating Systems Cornerstone attribute of equipment performance and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, Exelon did not maintain the cables for the EDG 1 and EDG 2 in an environment for which they were designed when the cables were allowed to be submerged in a below grade trench without ensuring adequate drainage. The team determined the finding could be evaluated using the SOP in accordance with IMC 0609, Significance Determination Process, Attachment 0609.04, Phase 1- Initial Screening and Characterization of Findings, Table 4a for the Mitigating Systems Cornerstone. The finding was of very low safety significance because it was a design or qualification deficiency confirmed not to result in a loss of operability.

The performance deficiency had a cross-culling aspect in the area of human performance, Resources, because Exelon did not ensure that personnel, equipment, procedures, and other resources were available and adequate to maintain long term plant safety through minimization of long-standing equipment issues. Specifically, Exelon did not correct long-standing deficiencies that allowed debris to block the drains allowing the cables to become submerged. Additionally, procedures were not adequate to ensure that the trenches were inspected and the drains were maintained to ensure that they remained free of debris. [IMC 0310, Aspect H.2.(a)]

Enforcement:

10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established to ensure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. Contrary to the above, as of August 2, 2010, EDG cable trench drains required to remove water from the EDG enclosure trenches were unable to function per their design and measures had not been put in place to ensure the safety-related EDG cables were maintained in accordance with their design. This resulted in low voltage control cables being subjected to an environment for which they were not designed or qualified for in a submerged condition. Because this finding was of very low safety significance, and it was entered into Exelon's corrective action program as IR 1097579, this violation is being treated as a non-cited violation (NCV) consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000219/2010008-02, EDG Low Voltage Control Cable Submergence)

.2.1.1 0480 Volt Load Center 1A2

a. Inspection Scope

The team reviewed load flow and short circuit current calculations for load center 1A2 to ensure conformance with the design basis for maximum bus loading, interrupting duty, bus bracing requirements, and the load center equipment vendor ratings. The team reviewed the acceptability of the coordination/protection calculation for the incoming line, bus tie and motor control center (MCC) feeder breaker for design basis load flow conditions. The team performed walkdowns of the 480V load center to assess the observable material condition and to identify potential seismic 1111 issues. The team reviewed transformer cooling fan operation to ensure consistency with design basis load requirements and procedural limitations. A review of IRs and corrective maintenance history was also performed for recurring issues to assess reliability of the load center.

The team reviewed surveillance tests on the incoming line breaker, cross-tie breaker, and MCC control center breaker trip units to ensure the results were consistent with design basis requirements.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green)involving a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XI, Test Control, because Exelon had not established a test program for safety-related load center transformer cooling fans to confirm the capability of the fans to cool the load center at its rated output. Specifically, Exelon had not established periodic testing to verify the 1A2 and 1B2 transformer cooling fans were functional to support the design rating allowed for in operational procedures.

Description:

Design modification, SDD OC-732A, Modification System Design Description, 480V Unit Substations 1A2 and 1B2 Transformer Cooling Fans Oyster Creek, was approved on January 2, 1986, to install fan systems, including manual and automatic fan controls, on the load center transformers. These fan systems were installed on load center transformers 1A2 and 1B2 to increase the load center rating from 2000 kVa without forced air to 2300 kVa on forced air. The modification design requirements for surveillance and in-service inspection, section 4.5, required, in part, for 1A2 and 1 B2 unit substations that the cooling system fans shall be periodically tested for operability, both in manual and automatic modes. The team found that this design requirement was not met since the station had not been periodically testing to ensure functionality of the fans.

The intended design of the 1A2 cooling fans, (FN-723-1, 2, and 3) is to auto start when the transformer oil temperature switch LTI-732-1 actuates on high oil temperature of 65 degrees Celsius. The fans provide for a higher transformer load rating as needed for certain plant configurations including cross tie operation of the 1B2 loads to the 1A2 transformer outlined in station procedure 338, 480 V Electrical System, revision 51.

Procedure 338 also states that the cooling fans allow loading of 2300 kVa (possible during a loss-of-coolant-accident) without transformer life expectancy degradation.

Exelon determined that the last recorded manual operation of the fans was during routine operator tours in the September 2001 timeframe and the current bi-monthly transformer electrical maintenance inspection task does not check the manual control circuitry. Additionally, refuel outage maintenance procedures for calibration of the oil temperature switches do not confirm the automatic start circuitry. Exelon entered the issue into the corrective action program as IR 1105417 and tested the fans during the inspection to ensure the fans were operational in the manual mode and would be in a ready to operate status, if needed.

Analysis:

The team determined that the failure to establish testing to demonstrate the capability of the transformer fans was a performance deficiency. This failed to meet the design requirement established in modification package SDD OC-732A which required in part, that the cooling system fans shall be periodically tested for operability both in the manual and automatic modes. The finding was determined to be more than minor because it was associated with the Mitigating Systems Cornerstone attribute of procedure quality and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the lack of testing impacts the objective because there is no method to determine the capability of the fans to support cooling of the transformers at their rated output. The team determined the finding could be evaluated using the SDP in accordance with IMC 0609, Significance Determination Process, Attachment 0609.04, Phase 1- Initial Screening and Characterization of Findings, Table 4a for the Mitigating Systems Cornerstone. The finding was of very low safety significance because it was not a design or qualification deficiency, did not represent an actual loss of safety function, and was not potentially risk significant due to a seismic, flooding, or severe weather initiating event.

The team did not identify a cross-cutting aspect with this finding because this was an old design/test issue and therefore was not reflective of current performance.

Enforcement:

10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires in part, that a test program shall be established to assure that all testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptable limits contained in applicable design documents.

Contrary to the above, as of August 24, 2010, Exelon had not established periodic operation and test requirements for the 1A2 and 1B2 load center transformer cooling fans. Specifically, Exelon did not ensure by periodic operation and testing that the manual and automatic modes of operation for the 1A2 and 1B2 transformer cooling fans were functional and capable of automatic operation in support of design ratings allowed for in operational procedures. Because this violation was of very low safety significance and it was entered into Exelon's corrective action program as IR 1105414 and IR 1105417, this violation is being treated as an NCV, consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000219/2010008-03, 1A2 and 1B2 480 V Load Center Transformer Cooling Fan Testing)

.2.1.1 1 4160 Volt Switchgear (1B)

a. Inspection Scope

The team reviewed load flow and short circuit current calculations to determine the switchgear design basis for maximum load, momentary and interrupting duty, and bus bracing requirements, and reviewed switchgear equipment vendor ratings for conformance with the design basis. The team also reviewed the design basis inputs for conservatism, confirmed use of the maximum switchyard voltage for short circuit calculations, and reviewed vendor equipment data for adequate margin in breaker momentary and interrupting duty. The team confirmed the calculated minimum voltage (for degraded grid conditions) and short circuit current (for maximum switchyard voltage)were based on the switchyard voltage schedule operating limits. The team reviewed preventive maintenance for selected breakers for corrective actions, component replacements, and the results of inspections/tests, including breaker timing tests to confirm capability for fast bus transfer. The team also reviewed the corrective maintenance history and IRs for issues affecting reliability. The team performed a walkdown of the 4160V switchgear to assess the material condition and to identify potential seismic II/I issues.

b. Findings

No findings were identified .

.2.1.1 2EDG-1 Batterv

a. Inspection Scope

The team inspected the EDG-1 battery to verify it was capable of performing its design basis function. The team reviewed calculations and vendor technical information to ensure that the battery was adequately sized to supply the design starting duty cycle. In particular, the evaluation focused on voltage drop calculations to verify adequate voltage I

would remain available for the starting sequence during design basis events. The team also reviewed the battery compartment ventilation to ensure the hydrogen generation concentration level would stay below acceptable levels during normal and accident conditions. The team verified that battery seismic spacers and restraints were properly installed to ensure that the EDG could be reliably operated in the event of a design basis earthquake. The team reviewed battery surveillance test procedures and results to verify that test acceptance criteria and frequency reqUirements satisfied TS and vendor specifications. The team reviewed the adequacy of the charger to charge and maintain the battery in the required condition. Finally, the team performed a walkdown of the battery and reviewed selected IRs to verify that design and testing issues related to the batteries were appropriately identified and corrected, and to assess the overall material condition of the battery.

b. Findings

No findings were identified .

.2.1.1 3 Startup Transformer (S181

a. Inspection Scope

The team reviewed one line diagrams, transformer nameplate, and vendor test results for impedance data to confirm that correct transformer impedances were utilized in electrical analyses. A walkdown of the transformer overcurrent protective relays was performed to observe settings and to determine conformance with relay setting documents. The team confirmed the adequacy of the overcurrent relay settings for design basis loading requirements. Additionally, the team reviewed transformer dissolved gas analysis (DGA) results and trending, and transformer bushing condition monitoring and trending for adverse conditions that could affect reliability. The team reviewed the modification history for potential impact on the design basis. The team performed a walkdown of the transformer to assess observable material condition. The team also reviewed the corrective maintenance history and IRs to ensure issues which affected reliability were appropriately resolved.

b. Findings

No findings were identified .

.2.1.1 4 DC Switchboard (El

a. Inspection Scope

The team inspected the 'E' direct current (DC) switchboard to verify that it could meet its design requirements. The team reviewed the UFSAR, DBD, vendor drawings, and procedures to identify the design basis and operational requirements for the switchboard. The team reviewed the DC protective breaker coordination study to verify that adequate protection existed for postulated faults in the DC system. A walkdown was performed to evaluate the material condition of the equipment and to determine if the environmental conditions in the switchboard area were in accordance with design assumptions. The team reviewed surveillance test procedures and results to verify that test acceptance criteria and frequency requirements were in accordance with TS and design basis assumptions. The team interviewed system and design engineers regarding the design aspects and operating history of the switchboard, and reviewed IRs to verify that design and testing issues related to the DC system were appropriately identified and corrected.

b. Findings

No findings were identified .

.2.1.1 5 Containment Spray Pump (P-21-1 8\

a. Inspection Scope

The team inspected the '8' containment spray pump to verify that it was capable of meeting its design basis requirements. The team reviewed applicable portions of the UFSAR, D8D, and drawings to identify the design basis requirements for the pump.

The team reviewed calculations and surveillance procedures to verify that the pump was capable of achieving design basis head/flow requirements during worst case design basis conditions and that test acceptance criteria were consistent with these requirements. The team reviewed the hydraulic calculations associated with system flowrate, pressure, and NPSH to ensure that the design inputs were reasonable.

The team interviewed design and system engineers to review the background of the design and system functional requirements as well as historical test performance results.

The team reviewed the maintenance program to ensure critical vendor recommendations were being implemented through periodic maintenance. In addition, the team reviewed work orders and IRs to identify failures or nonconforming issues, and to determine if these deficiencies were being adequately evaluated and corrected.

Finally, the team performed a walkdown of the containment spray pump, motor, and support systems to independently assess Exelon's configuration control, the pump's.

operating environment, and the pump's material condition. The team observed pump operating parameters to monitor the condition of the pump during two pump runs when in-service for torus cooling during the inspection period.

b. Findings

No findings were identified .

.2.1.1 6 Emergency Core Cooling Suction Strainer (S-21-501\

a. Inspection Scope

The team inspected the ECCS strainer to determine if the strainer can adequately pass the design basis flow without exceeding the pressure drop allowance when the strainer is loaded with the design basis volume of debris. Structural analyses were reviewed for the strainer, the torus flange connection, and the torus piping due to low factor of safety margin in the stress reports. The review of the strainer stress analysis included an evaluation of the applied loads, method of load combination, and an evaluation of the results from the stress analysis to ensure that the methodology was reasonable.

The team evaluated the calculation of debris that can enter the strainer following various large break loss-of-coolant scenarios. Included in this analysis was varying amounts of fine debris that settles on the bottom and walls of the torus during plant operation. The team reviewed results of torus inspections from the past six years to determine if loading from fine particles was within the debris accumulation specification that was used to calculate the pressure drop across the strainer. The team reviewed a video recording from a torus inspection to evaluate the condition of the strainers. The team reviewed a calculation that evaluated the potential of ingestion of steam into the ECCS strainer and suction piping following a design basis accident due to nitrogen and steam flow during the transient. The calculation design inputs, methodology, and conclusions were reviewed to ensure they were technically reasonable.

b. Findings

No findings were identified .

.2.1.1 7 A Emergency Isolation Condenser (NE-01A)

a. Inspection Scope

The team inspected the 'A' emergency isolation condenser (lC) to verify that it was capable of performing its design basis function. The team reviewed applicable portions of the UFSAR, the IC system notebook, and drawings to identify the design basis requirements for the IC and its support systems. The team reviewed associated design calculations to assess shell inventory requirements, level instrument accuracy, environmental qualification requirements, and isolation valve stroke times. The team reviewed operating logs and surveillance test results, and performed system walkdowns to verify that Exelon maintained critical process parameters within the design specified range. For example, the team compared IC shell level indication in the control room, locally at the ICs, and at the remote shutdown panel (for the B IC) to the range specified in the operating procedure. The team reviewed IC shell makeup surveillances and verified valve alignment in the field to ensure that the alternate water sources would remain available under accident conditions. Based on steam inlet thermocouple readings and shell temperature indication, the team independently assessed the steam/condensate interface level over time as a qualitative measure of the potential thermal cyclic stress on the upper tubes in each bundle. The team reviewed the shell side chemistry sampling results and the shell temperature and level trends over time to assess the structural integrity of the tubes (primary containment interface). The team reviewed the post-scram report, associated issue reports (IRs), and post-scram walkdown report for the most recent IC actuation to verify that the system actuated and performed as expected.

The team evaluated completed design modification documents to determine if the changes impacted the design and licensing basis requirements. The team performed a walkdown of the new demineralized water makeup tank, air accumulators, cross-tie isolation valves, and associated piping to verify that the as-installed configuration aligned with the as-evaluated design. The team reviewed IC system health and walkdown reports, maintenance history, and system performance trending data to verify that Exelon reliably maintained the IC and its support systems. The team discussed IC system design, testing, operation, and performance with the operators and the system manager to ensure that the system performed as designed. Additionally, the team walked down control room instrument panels, both ICs, DC and AC distribution panels, accessible portions of steam inlet and condensate return piping, and accessible portions of the makeup water systems (including the condensate storage tank) to assess the material condition and configuration control of these structures, systems and components (SSCs). The team also reviewed a sample of corrective action IRs related to the ICs, isolation valves and actuation circuitry to ensure that Exelon appropriately identified, characterized, and corrected problems related to these essential SSCs.

b. Findings

No findings were identified .

.2.2 Review of Low Margin Operator Actions (4 samples)

The team assessed manual operator actions and selected a sample of four operator actions for detailed review based upon risk significance, time urgency, and factors affecting the likelihood of human error. The operator actions were selected from a probabilistic safety assessment (PSA) ranking of operator action importance based on Risk Achievement Worth (RAW) and Risk Reduction Worth (RRW) values. The non-PSA considerations in the selection process included the following factors:

• Margin between the time needed to complete the actions and the time available prior to adverse reactor consequences;

• Complexity of the actions;

• Reliability and/or redundancy of components associated with the actions;

• Extent of actions to be performed outside of the control room;

• Procedural guidance to the operators; and

• Amount of relevant operator training conducted .

.2.2.1 Align Containment Spray in the Torus Cooling Mode

a. Inspection Scope

The team evaluated manual operator actions to align containment spray in the torus cooling mode to verify operator actions were consistent with design and licensing bases.

Specifically, operator critical tasks included:

• Recognize need to establish tours cooling

• Confirm mode select switch aligned to "torus cooling"

• Start containment spray pump

• Start ESW pump

• Start additional pumps as necessary The team interviewed licensed operators and operator simulator instructors, reviewed associated operating procedures and operator training, observed operator response during a simulator scenario, and directly observed operators establish torus cooling from the control room (condition based due to elevated torus temperature) to evaluate the operators' ability to perform the required actions. The team walked down applicable control and indicating panels in the simulator and in the main control room to assess the likelihood of cognitive or execution errors. The team evaluated the available time margins to perform the actions to verify the reasonableness of Exelon's operating procedures and risk assumptions. The team also reviewed equipment deficiency reports, and performed independent infield observations, to assess the material condition of the associated pumps, motors, heat exchangers, and support systems. In addition, the team walked down the containment spray system I components (including the ESW pumps) during and following two prolonged runs when placed in service for torus cooling during the inspection period. The team performed these walkdowns to independently verify that the systems operated as designed and to ensure that operating parameters (oil temperatures and levels, pump and motor vibrations) could support prolonged operation, if necessary.

b. Findings

• No findings were identified .

.2.2.2 Isolate Circulating Water Rupture in the Turbine Building

a. Inspection Scope

The team evaluated operator actions to recognize and mitigate a circulating water (CW)rupture in the turbine building (including the condenser bay). Specifically, operator critical tasks included:

• Recognize condition

• Direct response in accordance with alarm response procedure

• Determine cause

• Confirm flooding

• Isolate source The team interviewed licensed and non-licensed operators, reviewed associated alarm response procedures and operator training, and conducted a detailed walkdown of accessible portions of the turbine building with an equipment operator to evaluate the operators' ability to perform the required actions. In addition, the team independently walked down accessible portions of the turbine building and the reactor building corner rooms to assess the likelihood of cognitive or execution errors. The team evaluated the available time margins to perform the actions to verify the reasonableness of Exelon's alarm response procedures and risk assumptions. The team also reviewed equipment deficiency reports, maintenance history, and intemal flood analyses, and performed independent infield observations to assess the material condition of the associated SSCs, to assess potential internal flood vulnerabilities, and to ensure that Exelon maintained appropriate configuration control of critical design features.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green)involving a non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, because Exelon did not identify and correct a condition adverse to quality. Specifically, Exelon did not identify and correct an impaired ball float drain valve that had the potential to adversely impact two safety-related core spray pumps during an internal flooding event.

Description:

On August 23, 2010, the team identified an impaired ball float drain valve in the core spray system I corner room during an internal flood walkdown with Exelon personnel. The design basis for internal flooding is keeping water in the torus room area to prevent the corner rooms from flooding. The design feature that protects the redundant core spray corner rooms is the installed floor drain ball check valves. The team identified that the hose from an installed temporary catch containment (drip bag)was routed to the core spray pump room floor drain and inserted deep enough into the drain that it impaired the function of the installed ball float check valve within the drain.

The ball float check valve functions to close to prevent backflow from the common torus room drain system from entering the core spray system I pump room, containing the A and C main core spray pumps and motors. The pumps and motors are oriented horizontally and located less than a foot above the floor. In response to the team's concern, Exelon personnel initiated prompt action to remove the hose and restore the ball float check valve's functionality. Exelon's short-term corrective actions also included entering the issue into their corrective action program (IR 1105225) and improving configuration control. The team noted that the catch containment and associated drain hose for a B control rod drive pump packing leak (IR 745966) had been initially installed in the March 2008 timeframe.

On August 18, 2010, during a walkdown of the core spray system II corner room, containing the redundant Band D main core spray pumps, the team noted that the floor drain was clear and unimpaired and that the installed ball float check valve appeared to be in satisfactory condition. The team also noted stenCiling on the floor adjacent to the drain valve warning plant personnel of the installed ball float. The team noted that similar stenciling and/or warning labels did not exist in the core spray system I corner room. The team also noted that Exelon personnel had previously identified degraded conditions associated with the ball float check valve in the core spray system I corner room but failed to initiate a corrective action IR in each instance. Specifically, during their two-year preventive maintenance (PM) task on October 31, 2006, maintenance personnel documented that they found the ball valve jammed in the bottom of the valve, debris in the valve, and damage to the ball (R206671 0). During their two-year PM task on April 13, 2009, maintenance personnel documented that they removed the seat from the old drain valve but found no ball float installed (R2095953). The team noted that these represented missed opportunities to engage their corrective action program (CAP)that may have precluded the configuration control deficiency identified by the team in August 2010.

Analysis:

The team determined that the failure to identify and correct the degraded ball float drain valve was a performance deficiency that was reasonably within Exelon's ability to foresee and prevent. The finding was more than minor because it is associated with the configuration control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective of ensuring the capability, availability and reliability of systems (core spray pumps) that respond to initiating events to prevent undesirable consequences. The team performed a Phase 1 screening in accordance with IMC 0609, Significance Determination Process, Attachment 0609.04, "Initial Screening and Characterization of Findings," and determined the finding required a Phase 3 analysis since it screened as potentially risk significant due to flooding as it had the potential to degrade two trains (A and C main core spray pumps). After additional SDP Phase 3 analysis, utilizing insights from the Oyster Creek Individual Plant Examination of External Events (IPEEE) and the licensee's internal flooding risk model, the team determined the finding was of very low safety significance (Green) because flood mitigation that was impacted by the finding would have minimal impact on redundant equipment required to safely shut down the unit.

This finding had a cross-cutting aspect in the area of Problem Identification and Resolution, Corrective Action Program Component, because Exelon did not identify issues completely, accurately, and in a timely manner commensurate with their safety significance. Specifically, Exelon did not identify a degraded condition involving a non-functional ball float drain valve. (IMC 0310, Aspect P.1 (a))

Enforcement:

10 CFR 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. Contrary to the above, prior to August 24, 2010, Exelon did not promptly identify and correct a ball float drain valve deficiency that had the potential to adversely impact core spray system I pumps, during an internal flooding event. Because this violation was of very low safety significance (Green) and has been entered into Exelon's corrective action program (IR 1105225), this violation is being treated as a non-cited violation (NCV), consistent with Section 2.3.2 of the NRC Enforcement Policy. (NCV 05000219/2010008-04, Core Spray System I Pump Room Degraded Ball Float Drain Valve)

.2.2.3 Isolate Fire Protection Pipe Rupture in the Upper Cable Spreading Room

a. Inspection Scope

The team evaluated manual operator actions to identify and isolate a fire protection system pipe rupture in the upper cable spreading room (new cable spreading room, old mechanical equipment room) that presented an internal flood concern to risk Significant SSCs. Specifically, operator critical tasks included:

• Respond to an unexpected fire pump start

• Identify fire water pipe rupture

• Isolate fire water piping at appropriate location The team interviewed licensed and non-licensed operators, reviewed associated alarm response procedures and operator training, and observed an equipment operator respond to a simulated unexpected fire pump start to evaluate the operators' ability to perform the required actions. In addition, the team walked down fire protection piping and valves associated with this time critical action to assess the likelihood of cognitive or execution errors. The team evaluated the available time margins to perform the actions to verify the reasonableness of Exelon's alarm response procedures and risk assumptions. The team reviewed plant drawings and equipment deficiency reports to assess the material condition of the associated piping, valves, and support systems and to assess potential internal flood vulnerabilities. The team also walked down accessible portions of the fire water piping and equipment drains to independently assess Exelon's configuration control and the system's material condition. The walkdowns included the upper cable spreading room, control room, lower cable spreading room, and the turbine building 1-1 sump area.

b. Findings

No findings were identified .

.2.2.4 Align Fire Protection System To Instrument Air Compressor

a. Inspection Scope

The team evaluated manual operator actions to align the fire protection system for instrument air (IA) compressor cooling following a loss of the normal turbine building component cooling water (TBCCW) source. Specifically, operator critical tasks included:

• Align the IA compressor cooling valves

• Unlock and open the fire protection valve

• Remove pipe cap and connect appropriate hose

• Establish short or long-term cooling path The team interviewed licensed operators and non-licensed operators, reviewed associated operating procedures and operator training, and observed an equipment operator respond to a simulated loss of TBCCW to evaluate the operators' ability to perform the required actions. The team walked down the IA and fire protection piping and valves associated with this time critical task to assess the likelihood of cognitive or execution errors. The team evaluated the available time margins to perform the actions to verify the reasonableness of Exelon's operating procedures and risk assumptions.

The team also walked down the fire protection piping, IA compressors, and TBCCW heat exchangers and reviewed equipment deficiency reports to independently assess Exelon's configuration control and the material condition of the associated SSCs.

b. Findings

No findings were identified .

.2.3.1 Operating Experience Smart Sample FY 2008-01 - Negative Trend and

Recurring Events Involving Emergency Diesel Generators

a. Inspection Scope

NRC Operating Experience Smart Sample (OpESS) FY 2008-01 is directly related to NRC Information Notice (IN) 2007-27, "Recurring Events Involving Emergency Diesel Generator Operability." The team reviewed Exelon's evaluation of IN 2007-27 and their associated corrective actions. The team reviewed Exelon's EDG system health and walkdown reports, EDG corrective action condition IRs and work orders, leakage monitoring, and surveillance test results to verify that Exelon appropriately dispositioned EDG concerns. Additionally, the team independently walked down both EDGs on several occasions to inspect for indications of vibration-induced degradation on EDG piping and tubing and for any type of leakage (air, fuel oil, lube oil, jacket water). The team also directly observed portions of the No.1 and No.2 EDG monthly surveillance runs on August 16 and August 23, 2010, respectively, and performed post-run walkdowns to ensure Exelon maintained appropriate configuration control and identified deficiencies at a low threshold.

b. Findings

No findings were identified .

.2.3.2 NRC Information Notice 2007-11: Recent Operator Performance Issues at Nuclear

Power Plants

a. Inspection Scope

NRC IN 2007-11 discussed operator performance issues associated with inadequate alignment of safety-related systems, inadvertent operation and bumping hazards, and procedure use and adherence. The team reviewed Exelon's evaluation of IN 2007-11 and their associated follow-up response. The team independently walked down control room panels and accessible in-plant components/panels associated with the team's selected SSCs on several occasions to assess Exelon's configuration control and equipment protective measures. In addition, the team reviewed associated operating procedures, completed surveillance tests, corrective action IRs, and working blocking tags in the field to verify that operators complied with the prescribed requirements and maintained the systems in accordance with their design and licensing bases.

b. Findings

No findings were identified.

.2.3.3 NRC Information Notice 2005-11. Internal Flooding/Spray-Down of Safety-Related

Eguipment Due to Unsealed Eguipment Hatch Floor Plugs and/or Blocked Floor Drains

a. Inspection Scope

The team reviewed Oyster Creek's disposition of IN 2005-11 to assess Exelon's review and corrective actions associated with the issue. This issue discussed industry events where the possibility of flooding safety-related equipment was identified as a result of deficiencies with equipment hatch floor plugs, blockage of equipment floor drain systems, and invalid plant design basis calculations. The team reviewed the disposition of the IN as documented in IR 253533. The team also conducted walkdowns of a sample of susceptible areas and reviewed design documents to independently assess the potential vulnerabilities.

b. Findings

A finding of very low safety significance was identified in section 1R21.2.2.2 of the report involving an impaired ball float check valve which was designed to prevent water from backing up into the room due to a postulated internal flooding event. There were no additional findings identified.

OTHER ACTIVITIES

40A2 Identification and Resolution of Problems (IP 71152)

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

b. Findings

No findings were identified.

40A6 Meetings, Including Exit The team presented the inspection results to Mr. M. Massaro, Site Vice President, and other members of Exelon's staff at an exit meeting on August 27, 2010. The team reviewed proprietary information, which was returned to Exelon at the end of the inspection. The team verified that none of the information in this report is proprietary.

ATTACHMENT

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Exelon Personnel

A. Agarwall, Electrical Design Engineer

T. Carroll, MOV Engineer

M. Filippone, System Manager

A. Kazarian, System Manager

P. Procacci, Electrical Design Engineer

C. Ricketts, System Manager

S. Schwartz, System Manager

J. Tabone, System Manager

LIST OF ITEMS

Opened and Closed

05000219/2010008-01 NCV Scaffold Installation Procedure Not Properly Implemented (1 R21.2.1.6)

05000219/2010008-02 NCV EDG Low Voltage Control Cable Submergence (1 R21.2.1.9)

05000219/2010008-03 NCV 1A2 and 1B2 480 V Load Center Transformer Cooling Fan Testing (1R21.2.1.10)

05000219/2010008-04 NCV Core Spray System I Pump Room Degraded Ball Float Drain Valve (1 R21.2.2.2)