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Component Design Bases Inspection Report 05000352/2015007 and 05000353/2015007
	ML15251A438
Person / Time
Site:	Limerick
Issue date:	09/08/2015
From:	Krohn P G; Engineering Region 1 Branch 2
To:	Bryan Hanson; Exelon Generation Co, Exelon Nuclear
	Krohn P G
References
	IR 2015007
	Download: ML15251A438 (35)
	v • d • e

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 2100 RENAISSANCE BLVD., SUITE 100 KING OF PRUSSIA, PA 19406-2713

Mr. Bryan Hanson Senior Vice President, Exelon Generation Company, LLC President and Chief Nuclear Officer, Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT: LIMERICK GENERATING STATION - COMPONENT DESIGN BASES INSPECTION REPORT 05000352/2015007 AND 05000353/2015007

Dear Mr. Hanson:

On July 10, 2015, the U.S. Nuclear Regulatory Co mmission (NRC) completed the onsite portion of an inspection at the Limerick Generating Station (LGS), Units 1 and 2. The enclosed inspection report documents the inspection results, which were preliminarily discussed on July 10, 2015, with Mr. Rick Libra, Limerick Site Vice President, and other members of your staff. Subsequent to the onsite inspection, continued dialogue and evaluation continued for two of the items discussed on July 10, 2015. The NRC's conclusions on these items were discussed via teleconference on July 30, 2015, with Mr. Wayne Lewis, Senior Design Engineering Manager, 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 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 two NRC-identified findings, both of which were of very low safety significance (Green). Both of the findings were determined to be violations of NRC requirements. However, because of the very low safety significance and because they were both entered into your corrective action program, the NRC is treating these findings as non-cited violations (NCV) consistent with Section 2.3.2.a of the NRC's Enforcement Policy. If you contest any of the NCVs 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 Senior Resident Inspector at LGS. In addition, if you disagree with the cross-cutting aspect assigned to the findings 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 Senior Resident Inspector at LGS. September 8, 2015 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 public inspection in the NRC Public Docket Room or from the Public ly Available Records component of NRC's document system, Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/ Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety

Docket Nos. 50-352 and 50-353 License Nos. NPF-39 and NPF-85

Enclosure:

Inspection Report 05000352/2015007 and 05000353/2015007 w/Attachment: Supplemental Information cc w/encl.: Distribution via ListServ

ML15251A438 SUNSI Review Non-Sensitive Sensitive Publicly Available Non-Publicly Available OFFICE RI/DRS RI/DRS RI/DRP RI/DRS NAME SPindale WCook FBower PKrohn DATE 8/20/15 8/27/15 9/8/15 9/8/2015

i Enclosure U.S. NUCLEAR REGULATORY COMMISSION REGION I Docket Nos. 50-352; 50-353

License Nos. NPF-39, NPF-85

Report Nos. 05000352/2015007 and 05000353/2015007

Licensee: Exelon Generation Company, LLC

Facility: Limerick Generating Station, Units 1 and 2

Location: Sanatoga, PA

Inspection Period: June 8 through July 30, 2015

Inspectors: S. Pindale, Senior Reactor Inspector, Division of Reactor Safety (DRS),

Team Leader K. Mangan, Senior Reactor Inspector, DRS J. Lilliendahl, Reactor Inspector, DRS N. Floyd, Reactor Inspector, DRS N. Della Greca, NRC Electrical Contractor M. Yeminy, NRC Mechanical Contractor

Approved By: Paul G. Krohn, Chief Engineering Branch 2

Division of Reactor Safety ii

SUMMARY OF FINDINGS

IR 05000352/2015007 and 05000353/2015007; 6/8/2015 - 7/30/2015; Limerick Generating Station, Units 1 and 2; Component Design Bases Inspection.

The report covers the Component Design Bases Inspection conducted by a team of four U.S. Nuclear Regulatory Commission (NRC) inspectors and two NRC contractors. Two findings of very low safety significance (Green) were identified, which were considered to be non-cited violations (NCV). The significance of most findings is indicated by their color (Green, White, Yellow, Red) using Inspection Manual Chapter (IMC) 0609, "Significance Determination Process." Cross-cutting aspects associated with findings are determined using IMC 0310,

"Components Within the Cross-Cutting Areas." 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 2006.

A. NRC-Identified and Self-Revealing Findings

Cornerstone: Mitigating Systems

Green.

The team identified a finding of very low safety significance involving a non-cited violation (NCV) of the 10 CFR Part 50, Appendix B, Criterion III, "Design Control," in that Exelon did not verify and assure in design basis calculations, that adequate voltage would be available for starting Class 1E accident mitigating motors when the safeguards buses are powered by the emergency diesel generators (EDG). Specifically, in the calculation performed to evaluate voltage available to individual motors when they are powered by the EDGs, Exelon assumed that the generator output voltage would be 4285 Volts, alternating current (Vac), rather than the minimum voltage allowed by station technical specifications (4160 Vac). Additionally, the electrical ratings of loads powered by the EDG were not adjusted for the maxi mum frequency allowed by station technical specifications (61.2 hertz (Hz)). As a result, the starting voltage for some of the safety-related motors would not have been acceptable under EDG generator voltage and frequency limiting conditions. In response, Exelon entered the issue into their corrective action program and performed evaluation that determined that EDG actual test results demonstrated the EDGs to be operable. The team review of the evaluation determined it to be reasonable.

This finding was more than minor because it was similar to Example 3.j of NRC IMC 0612, Appendix E, and was associated with the Design Control 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. The team determined the finding was of very low safety significance because it was a design deficiency confirmed not to result in a loss of safety-related motor operability or functionality. The team determined this finding had a cross-cutting aspect in the area of Problem Identification and Resolution (Identification, Aspect P.1), because during a calculation revision in 2014, Exelon did not recognize that the limits of voltage and frequency allowed by the station technical specifications affected the calculation results and, therefore, did not completely and accurately identify the issue and revise the calculation in accordance with the station's corrective action program requirements. (Section 1R21.2.1.1)iii

Green.

The team identified a finding of very low safety significance involving a non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, "Design Control," in that Exelon's design control measures did not verify the adequacy of the design regarding adequate direct current voltage (Vdc). Specifically, Exelon did not ensure that adequate voltage existed to emergency diesel generator (EDG) relays and output breaker spring charging motors. Additionally, the team determined that the overall impact to voltage drop calculations was not adequately assessed when the temporary battery cart is used.

Following identification of the issue, Exelon entered it into their corrective action program and evaluated the operability of the batteries, concluding that the affected DC components would function at the current battery capacities. The team's review of the evaluation determined it to be reasonable.

The finding was more than minor because it was similar to Example 3.j of NRC IMC 0612, Appendix E, and was associated with the Design Control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The team determined the finding was of very low safety significance because it was a design deficiency affecting the safety-related batteries that did not result in the loss of operability or functionality. The team determined this finding had a cross-cutting aspect in the area of Human Performance, (Documentation, Aspect H.7) because the battery sizing calculation was revised on March 15, 2014, which provided an opportunity to identify the inaccuracies of the battery calculations. (Section 1R21.2.1.2)

B. Licensee-Identified Violations

None

REPORT DETAILS

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R21 Component Design Bases Inspection (IP 71111.21)

.1 Inspection Sample Selection Process

The team selected risk significant components for review using information contained in the Limerick (LGS) Probabilistic Risk Assessment (PRA) and the U.S. Nuclear Regulatory Commission's (NRC) Standardized Plant Analysis Risk (SPAR) model for LGS. Additionally, the team referenced the Risk-Informed Inspection Notebook for LGS in the selection of potential components for review. In general, the selection process focused on components 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 associated with both safety-related and non-safety related systems and included a variety of components such as pumps, transformers, operator actions, electrical busses, and valves.

The team initially compiled a list of components based on the risk factors previously mentioned. Additionally, the team reviewed the previous component design bases inspection (CDBI) reports (05000352 and 353/2007007, 05000352 and 353/2009006, and 05000352 and 353/2012007) and excluded those com ponents previously inspected. The team then performed a margin assessment to narrow the focus of the inspection to 19 components and three operating experience (OE) items. The team selected two components based on large early release frequency (LERF) implications. 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 OE. Finally, consideration was also given to the uniqueness and complexity of the design and the available defense-in-depth margins.

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 and licensing bases. Summaries of the reviews performed for each component and OE sample are discussed in the subsequent sections of this report. Documents reviewed for this inspection are listed in the Attachment.

.2 Results of Detailed Reviews

.2.1 Results of Detailed Component Reviews (21 samples)

.2.1.1 D14 Emergency Diesel Generator

a. Inspection Scope

The team reviewed the electrical and mechanical capabilities of Unit 1 emergency diesel generator (EDG), D14. The design function of EDG D14 is to provide standby power to the 4160 Vac safety-related emergency switchgear bus D14 when the preferred offsite power is not available. The electrical evaluation of the EDG focused on its ability to supply power to the safety-related loads during design basis abnormal and accident events. Specifically, the team reviewed transient and steady state loading analyses and the design capabilities of the EDG to confirm its ability to accept and run the required loads. The team reviewed the brake horsepower basis for selected pump motors to ensure that the loads were adequately considered in the loading study at conservative motor operating conditions. The team also reviewed EDG voltage settings and voltage drop calculations to verify that adequate voltage was provided to the safety-related loads during worst-case loading conditions. Additionally, the team reviewed short circuit calculations and the 4160 Vac coordination analysis to ensure that the switchgear equipment was adequately rated and the protective devices selectively coordinated such that the loads and cables were adequately protected without interruption of service to other components during overload or faulted conditions. The team reviewed bus voltage relay settings and control schematic wiring diagrams to confirm that the EDG would start automatically during a loss-of-offsite power or degraded voltage condition and that the bus loading would occur, in accordance with design requirements and licensing bases.

The team reviewed the EDG surveillance test procedures and results to verify that such testing complied with technical specification (TS) requirements and, in particular, that during the sequential starting of loads, the EDG had sufficient capability to accelerate the loads within the time periods specified in the Updated Final Safety Analysis Report (UFSAR). The team reviewed the details associated with an EDG time delay relay testing minor deficiency, wherein the safety function could still be performed but the team evaluated a potential timing and sequencing issue with the alternate source of offsite power and EDG breakers closing on safety-related buses within the same timeframe (Issue Report (IR) 02535151).

The team also inspected the EDG mechanical support systems to ensure they were capable of meeting their design basis functions, including the fuel oil, lubricating oil, starting air, engine cooling, and room cooling systems. The team reviewed the fuel oil consumption calculation to ensure the quantity of fuel on site was consistent with design and licensing requirements. Engine air start system check valve leakage testing and associated calculations were reviewed to ensure engine starting capability from the stored air supply was adequate to start the EDG during worst case delayed starting assumptions. The team reviewed engine heat exchanger design calculations and recent heat exchanger inspection results to ensure adequate cooling water flow rate and heat transfer assumptions were maintained.

The team also witnessed a monthly surveillance test of the diesel engine which was conducted using the "slow start" method to verify the adequacy of the surveillance, to determine whether all elements of the procedure were completed, and to verify that components were operating as designed.

The team reviewed selected maintenance procedures and completed work records to evaluate whether the EDG was being properly maintained. The team reviewed completed surveillances to determine if the EDG was being tested in accordance with the TSs. The team also interviewed the responsible engineers and performed walkdowns of the EDG and related equipment to assess Exelon's configuration control, the material condition, the operating environment, and potential external hazards. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green) involving a non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion III, "Design Control," in that Exelon did not verify and assure in design basis calculations, that adequate voltage would be available for starting Class 1E accident mitigating motors when the safeguards buses are powered by the EDGs. Specifically, in the calculation performed to evaluate voltage available to individual motors when powered by the EDGs, Exelon assumed that the generator output voltage would be 4285 Vac, rather than the minimum voltage allowed by the station TSs (4160 Vac). Additionally, the kilowatt (kW) and kilovolt amperes (KVA) ratings of the loads powered by the EDG were assumed to be at nominal frequency (60 Hz) rather than at the maximum frequency allowed by the station TSs (61.2 Hz). As a result, the starting voltage for some of the safety-related motors may not have been acceptable under limiting EDG voltage and frequency conditions.

Description:

Calculation 6380E-08, "Diesel Generator Voltage Regulation Study," was prepared "to predict and evaluate the EDG voltage transient during the addition of step load changes to assure that the capability of the on-site power system is not degraded to a point that prevents the starting and running of all engineered safety feature and emergency shutdown loads required for: 1) a loss-of-offsite power (LOOP); and 2) a loss-of-coolant accident (LOCA) coincident with a LOOP."

The team's review of the design inputs determined that Exelon had assumed a starting EDG voltage of 4285 Vac.

Additionally, the team observed that the calculation had assumed a nominal frequency of 60 Hz. Based on the assumed voltage and frequency, the calculation concluded that, when powered from the EDG, all motors received an acceptable starting voltage, albeit the margin for some 460 Vac motors was very limited both under LOOP and LOCA-LOOP conditions.

To confirm the acceptability of the calculation assumptions the team reviewed the UFSAR and the TSs. The team determined that TS Surveillance Requirement (SR) 4.8.1.1.2.a.4 required verification that "the diesel can start and gradually accelerate to synchronous speed with generator voltage and frequency at 4280 +/-

120 Vac and 60 +/-

1.2 Hz," and that other SRs have similar requirements. Simila rly, the team found that these same voltage and frequency requirements were reflected in the applicable plant surveillance procedures.

The team identified that the surveillance procedures can allow voltages less than the calculated 4285 Vac and higher than the calculated nominal 60 Hz, as permitted by the TSs. However, in light of the very limited margin available on several safety-related motors, the team questioned the acceptability of the assumptions formulated in calculation 6380E-08 compared to the tested acceptance criteria and questioned Exelon as to whether the surveillance acceptance criteria were potentially non-conservative. To address the team's concern, Exelon conducted preliminary analyses to determine the minimum required EDG voltage to assure that adequate starting voltage at all safety-related motors, assuming EDG operation at a maximum frequency of 61.2 Hz.

Exelon staff determined that when the safety-related motors were powered by the EDG, the minimum EDG voltage should be not less than 4235 Vac and that EDG surveillance testing should confirm that the voltage regulator maintained such minimum voltage.

Exelon entered the team's finding in the corrective action program (IR 2525662) and performed an operability evaluation to confirm that, under current governor and voltage regulator settings, all motors remained operable. The team reviewed Exelon

's operability assessment and agreed that, based upon test results demonstrating that the voltage never fell below the calculated value, the EDGs remained operable.

In addition, the team discussed the applicability of NRC Administrative Letter (AL) 98-10, "Dispositioning of Technical Specifications that are Insufficient to Assure Plant Safety."

Specifically, in this case, the TSs allowed the EDG minimum voltage (4160 Vac) and maximum frequency to values that are not bounded by the governing design calculation (4285 Vac, 61.2 Hz). Accordingly, and consistent with AL 98-10, Exelon plans to impose administrative controls as a short term compensatory measure (for the TS surveillance test); and will evaluate an amendment to the TS, with appropriate justification and schedule, for submittal to the NRC in a timely fashion.

Analysis:

The team determined that the failure to confirm that all safety-related motors had adequate starting voltage when powered by the EDG was a performance deficiency. Specifically, Exelon did not consider the effects of minimum voltage and maximum frequency allowed by TSs on the ability of the engineered safety feature and emergency shutdown loads to start and run, as assumed in the design basis calculation of record, 6380E-08. As a result, at the minimum voltage allowed by the TSs, some of the motors may not have the minimum voltage specified in the applicable industry standards and calculation assumptions. The finding was more than minor because it was similar to Example 3.j of NRC Inspection Manual Chapter (IMC) 0612, Appendix E, "Examples of Minor Issues," which determined that calculation errors would be more than minor if, as a result of the errors, there was reasonable doubt on the operability of the component.

In addition, the finding was associated with the Design Control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences.

The team performed a risk screening, in accordance with IMC 0609, Appendix A, "Significance Determination Process for Findings At-Power," using Exhibit 2, "Mitigating Systems Screening Questions," and determined the finding was of very low safety significance (Green) because it was a design deficiency affecting motor starting capability that did not result in the loss of operability or functionality of the affected safety-related

equipment. Specifically, a preliminary analysis determined that existing settings for the EDG speed governor and voltage regulator were adequate to prevent the voltage at all motors from dropping below the required minimum. Additionally, results of recent surveillance tests indicated that the EDG voltage never fell below the calculated value.

The team determined that this finding had a cross-cutting aspect in the area of Problem Identification and Resolution (Identification), because during a revision of the calculation in 2014, Exelon did not recognize that the limits of voltage and frequency allowed by the TSs affected the calculation results and, therefore, did not completely and accurately identify the issue and revise the calculation in accordance with the station

's corrective action program requirements. (IMC 0310, Aspect P.1)

Enforcement:

10 CFR Part 50, Appendix B, Criterion III, "Design Control," requires, in part, that design control measures shall provide for verifying the adequacy of design, and for the selection and review for suitability of equipment that is essential to the safety related functions of structures, systems, and components. Contrary to the above, prior to July 10, 2015, Exelon's design control measures had not verified the adequacy of the design basis calculation to assure that adequate voltage would be available for starting Class 1E accident mitigating motors when the safeguards buses are powered by the EDGs. Specifically, in the design basis calculation performed to evaluate voltage drop to individual motors when they are powered by the EDGs (6380E-08), Exelon assumed that the EDG output voltage would be 4280 Vac, rather than the minimum voltage allowed by the TSs (4160 Vac). Additionally, the loads were not adjusted for the maximum

frequency allowed by the TSs (61.2 Hz) or the administrative limits imposed on the EDG governor. Because this violation was of very low safety significance (Green) and was entered into Exelon's corrective action program (IR 2525662), this violation is being treated as an NCV, consistent with Section 2.3.2.a of the NRC's Enforcement Policy. (NCV 05000352;05000353/2015007-01, Failure to Verify Adequacy of EDG Voltage to Start Safety-Related Motors)

.2.1.2 Division I 125/250 Vdc Station Battery and Direct Current Bus (2 samples)

a. Inspection Scope

The team inspected the Division I 125/250 voltage direct current (Vdc) station battery and direct current (DC) bus at Unit 1 to evaluate whether the battery and bus could perform the design basis function to provide DC power to the Division I switchgear following postulated design basis accidents.

The team reviewed the UFSAR, TSs, TS Bases, the system design description, drawings, and procedures to identify the performance requirements for the battery and associated DC bus. The team reviewed design calculations to assess the adequacy of the battery's sizing to ensure it could power the required equipment for a sufficient duration, and at a voltage above the minimum required for equipment operation. The team reviewed battery room temperature monitoring to verify that environmental conditions would not adversely affect the life of the battery and that the battery would be capable of performing its intended safety function late in life during normal and postulated accident conditions. The team reviewed battery test results, including discharge tests to ensure the testing was in accordance with design calculations, plant TSs, vendor recommendations, and industry standards; and that the results confirmed acceptable performance of the battery.

Design and system engineers were interviewed regarding the design, operation, testing, and maintenance of the battery.

The team reviewed the design and operation of the switchgear bus and associated distribution panels. The review evaluated whether the loading of the DC bus was within equipment ratings and determined whether the bus could perform its design basis function to reliably power the associated loads under worst case conditions. Specifically, the team reviewed calculations and drawings including voltage drop calculations, short circuit analyses, and load study profiles to evaluate the adequacy and appropriateness of design assumptions.

The team walked down the Division I 125 Vdc battery, bus, and distribution panels to independently assess their material condition and to determine if the system alignment and operating environment was consistent with design basis assumptions. Finally, the team reviewed corrective action documents and system health reports to determine if there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

Introduction:

The team identified a finding of very low safety significance (Green) involving an NCV of 10 CFR Part 50, Appendix B, Criterion III, "Design Control," in that Exelon's design control measures did not verify the adequacy of the design regarding adequate DC voltage. Specifically, the team determined that Exelon did not ensure that adequate voltage existed to EDG relays and output breaker safety-related spring charging motors (SCM). Additionally, the team determined that the overall impact to voltage drop calculations was not adequately assessed when the temporary battery cart

is used.

Description:

The team reviewed three pertinent calculations to assess the capability of the safety-related batteries to provide adequate voltage to the DC loads:

LE-052, Class 1E Battery Load Duty Cycle Determination

LE-069, Class 1E 125 Vdc System Voltage Analysis

LE-053, Determine Acceptable Cable Size for Temporary Cable Jumpers Used During Battery Cell Maintenance/Testing The team noted that the purpose of LE-052 was to show that battery voltage stays above 105 Vdc when DC loads operate under worst-case conditions. The purpose of the LE-069 calculation was to show that at 105 Vdc, all the DC loads would have sufficient voltage. Finally, calculation LE-053 was developed to demonstrate that even with the increased resistance of the temporary battery cart, there would be sufficient voltage for all of the loads.

The team noted that the calculated worst case component voltage was lower than the manufacturer recommended minimum voltage for EDG relays and several safety-related SCMs. The EDG relay manufacturer required 106 Vdc, however, the calculation showed 94 Vdc available. The SCM manufacturer required 90 Vdc, but the calculation showed 76 Vdc available. A sample of EDG relays and SCMs was tested in the 1994 timeframe to verify that the components would operate at the calculated minimum voltage (i.e., at a value less than the manufacturer recommended voltages); and actions were internally recommended to perform future periodic testing of these devices to provide assurance that they would continue to operate at the reduced voltage. However, the actions to periodically retest the EDG relays and SCMs were not successful in that maintenance procedures were never updated to require periodic retesting at the calculated minimum voltages. The team noted that new relays of the same model as the EDG relays are tested at the calculated minimum voltage prior to installation in the plant; and SCMs are tested, but at the manufacturer's minimum rather than at the lower value in the calculation

(76 Vdc).

At Limerick, a temporary battery cart is used to allow online battery maintenance. The cart is designed to jumper out several cells from the battery and jumpers in cells from the cart. The cart is designed to be fully qualified as a replacement for the cells. Calculation LE-053 documents that, although the battery cart causes increased resistance and therefore increases voltage drop, there would be sufficient voltage drop margin so that the battery would remain operable. The LE-053 calculation is dependent on LE-052 and appropriately requires that LE-053 be reviewed whenever LE-052 is revised. The team reviewed the current LE-053 review as documented in the most recent revision to LE-052 and determined that it was inadequate. Specifically, the review included incorrect calculations and erroneous assumptions regarding the worst case increase in voltage drop (~3 Vdc) from the battery cart and the acceptability of being below the required voltage for motor-operated valves and relays to change position, and therefore would invalidate the use of the battery cart regarding Divisions I, II, IIII, and IV.

In response to the team's observations, Exelon entered the DC voltage issues into their corrective action program, evaluated the operability of the affected components, and initiated actions for increased testing and further evaluation. Specifically, Exelon re-calculated the voltage drops using the current battery capacity to demonstrate the ability to perform the intended safety functions, verified the current battery service life calculations, reviewed operating experience to verify no negative trend existed for EDG relay performance, and implemented actions to promptly test spare components, and to periodically test the affected components. In addition, Exelon verified that the temporary battery cart will not be used for the Division III and Division IV batteries until more detailed evaluation can be done to show that the battery cart has sufficient margin for these batteries (their evaluation demonstrated that the cart could be used for Division I and II batteries). The team reviewed the evaluations and agreed that there was reasonable assurance that the batteries will provide adequate voltage to the safety-related components. In the longer term, Exelon planned additional evaluations to ensure operability through the end of expected battery service life.

Analysis:

The team determined that the failure to ensure adequate voltage was available to safety-related DC equipment was a performance deficiency. Specifically, Exelon did not ensure that adequate voltage existed to EDG relays and breaker SCMs and did not ensure the overall impact to voltage drop was adequately assessed when the temporary battery cart was used. The finding was more than minor because it was similar to Example 3.j of NRC IMC 0612, Appendix E, "Examples of Minor Issues," which determined that calculation errors would be more than minor if, as a result of the errors, there was reasonable doubt on the operability of the component. In addition, the finding was associated with the Design Control attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable

consequences.

The team performed a risk screening, in accordance with IMC 0609, Appendix A, "Significance Determination Process for Findings At-Power," using Exhibit 2, "Mitigating Systems Screening Questions," and determined the finding was of very low safety significance (Green) because it was a design deficiency affecting the safety-related batteries that did not result in the loss of operability or functionality. Specifically, a preliminary analysis determined that the affected components would function at the current battery capacities.

The team determined that this finding had a cross-cutting aspect in the area of Human Performance (Documentation), because the battery sizing calculation LE-052 was revised on March 15, 2014, which provided an opportunity to identify the inaccuracies of the battery calculations. (IMC 0310, Aspect H.7)

Enforcement:

10 CFR Part 50, Appendix B, Criterion III, "Design Control," states, in part, that measures shall be established to provide for verifying the adequacy of design.

Contrary to the above, prior to July 10, 2015, Exelon's design control measures had not verified the adequacy of the design regarding adequate DC voltage. Specifically, Exelon did not perform periodic re-testing of EDG relays or output breaker spring charging motors at reduced voltage, and the DC voltage drop was not adequately assessed when the temporary battery cart was used. Because this finding is of very low safety significance (Green) and was entered into Exelon's corrective action program (IRs 2525692, 2526231, and 2526233), the violation is being treated as an NCV, consistent with Section 2.3.2.a of the NRC's Enforcement Policy. (NCV 05000352;05000353/2015007-02, Failure to Verify Adequate Voltage Available for DC Equipment)

.2.1.3 Reactor Core Isolation Cooling System Logic

a. Inspection Scope

The team inspected the Unit 1 reactor core isolation cooling (RCIC) system logic to

evaluate whether it could perform its design basis function to automatically initiate the RCIC system to provide a means for coolant injection to the reactor when the reactor is isolated. The logic also isolates the RCIC system when reactor water level increases to its high setpoint.

The team reviewed the UFSAR, TSs, TS Ba ses, the system design basis document (DBD), drawings, and procedures to identify the performance requirements for the RCIC system logic. The team reviewed associated surveillance testing of the RCIC system circuitry to verify its performance under design basis conditions. The team reviewed calculations and discussed the design, operation, and maintenance of the system with engineers. The team also conducted a walkdown of related and accessible RCIC system components to assess the material condition of the equipment and to evaluate whether the installed configuration was consistent with the plant drawings, procedures, and the design bases. Finally, the team reviewed corrective action documents and system health reports to determine if there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.4 Reactor Core Isolation Cooling System Flow Controller

a. Inspection Scope

The team inspected the Unit 1 RCIC system flow controller to evaluate whether it could perform its design basis function to automatically control RCIC system flow to the reactor during transient and postulated accident scenarios. The team reviewed the UFSAR, TSs, TS Bases, the system DBD, drawings, and procedures to identify the performance requirements for the RCIC system flow controller. The team reviewed associated testing and calibration of the flow controller to verify its performance under design basis conditions; and that the controller maintained RCIC pump flowrates and turbine speed within design specifications. The team reviewed calculations and discussed the design, operation, and maintenance of the flow controller with engineers. The team also conducted a walkdown of related and accessible RCIC system components to assess the material condition of the equipment and to evaluate whether the installed configuration was consistent with the plant drawings, procedures, and the design bases. Finally, the team reviewed corrective action documents and system health reports to determine if there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.5 4160 Vac Bus D14

a. Inspection Scope

The team inspected the Unit 1 4160 Vac switchgear bus D14 to verify that it was capable of meeting its design basis requirements. The team reviewed selected calculations for the electrical distribution system, in cluding load flow/voltage drop, degraded voltage protection, short-circuit, and electrical protection and coordination calculations. The adequacy and appropriateness of design assumptions and calculation results were reviewed to verify that bus capacity was not exceeded and bus voltages remained above minimum acceptable values under design basis conditions. The switchgear's protective device settings and breaker ratings were reviewed to ensure that selective coordination was adequate for protection of connected equipment during worst-case short-circuit conditions. Automatic and manual transfer schemes between alternate offsite sources and the emergency diesel generator were also reviewed to confirm that such transfers were in accordance with DBDs. Voltage protection schemes were reviewed for degraded and loss of voltage relaying. The team reviewed degraded and loss of voltage relays settings to verify that they were set in accordance with design calculations, and that associated calibration procedures were consistent with calculation assumptions, associated time delays, and setpoint accuracy calculations. In addition, the team reviewed selected surveillance test results to determine whether design assumptions and

system performance requirements were appropriately verified.

The team reviewed the adequacy of instrumentation/alarms available to operators. To ensure that breakers were maintained in accordance with industry and vendor recommendations, the team reviewed the preventive maintenance templates.

Component maintenance history and corrective action program reports were also reviewed to verify that deficiencies and potential degradation mechanisms were appropriately identified and resolved. The team performed a visual non-intrusive inspection of accessible portions of the safety-related 4160 Vac switchgear to assess the installation configuration, material condition, and potential vulnerability to hazards.

Finally, the team reviewed corrective action documents and system health reports to determine if there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.6 4160 Vac - 480 Vac Transformer D144

a. Inspection Scope

The team inspected the 4160 Vac to 480 Vac transformer D144 at Unit 1 to verify that it was capable of performing its design basis function. The team reviewed calculations, drawings, maintenance procedures, and vendor manuals, and assessed the sizing, impedance, loading, protection features, and voltage tap setpoints for the transformer to ensure adequate voltage would be supplied to the vital 480 Vac load center.

The team reviewed the adequacy and appropriateness of design assumptions in calculations related to motor starting and loading voltages to verify that voltage to connected loads would remain above the minimum acceptable values. The team also reviewed the ampacity of associated cables to ensure maximum cable ratings were not exceeded during operation based on lowest allowed voltage supplied from the 4 kV vital bus. Additionally, the team reviewed the protective device settings to ensure that the feeder cables and transformer were protected in accordance with industry standards.

A visual walkdown of the equipment was performed and engineers were interviewed to assess the installation configuration, material condition, and potential vulnerability to hazards. Finally, the team reviewed corrective action documents to evaluate whether there were any adverse trends associated with the transformer and to assess Exelon's capability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.7 Residual Heat Removal Service Water Pump Motor 'A'

a. Inspection Scope

The team reviewed the Unit 1 residual heat removal service water (RHRSW) pump motor

a. Inspection Scope

The team inspected the Unit 1 and 2 common RHRSW system piping to evaluate whether it was capable of meeting its design basis requirement to provide cooling water flow for removing heat from the RHR heat exchangers. The inspection included a review of internal piping corrosion that had existed for several years and Exelon's associated monitoring and corrective actions. The team reviewed the TS, UFSAR, the DBD, design bases calculations and modifications to eval uate whether the system's required flows, pressures, and operating conditions for various system configurations were bounded by design assumptions. Additionally, the team evaluated associated non-destructive examination results for RHRSW piping integrit y. The team performed a walkdown of the accessible portions of the RHRSW piping and interviewed engineers to assess the material condition of the system. Finally, the team reviewed condition reports and system health reports to determine the overall health of the system, and determine if issues entered into the corrective action program were appropriately addressed.

b. Findings

No findings were identified.

.2.1.1 2 High Pressure Coolant Injection System Support Components

a. Inspection Scope

The team inspected the Unit 2 high pressure coolant injection (HPCI) system pump and turbine support systems to evaluate whether they were adequate to maintain the HPCI system capabilities per its design basis and operational requirements. The inspection included a review of the lubricating oil/turbine system, cooling system, turbine gland seal system, minimum flow valve, and HPCI discharge check valve. The team performed a walkdown of the HPCI system and interv iewed system and design engineers to assess the material condition of the components. The team reviewed the TS, UFSAR, HPCI DBD, and design bases calculations to determine the required flows, pressures, and operating conditions for various system configurations in order to determine the support

system operational requirements. Additionally, the team evaluated calculations, technical evaluations, condition reports, and in-service test (IST) data. The review assessed whether TS and design basis requirement s could be achieved and IST acceptance criteria were appropriate. The team also reviewed the HPCI lubricating oil cooler heat transfer evaluation, periodic inspection results, tube plugging limits, and current tube plugging to verify that design basis heat removal requirements were satisfied. Finally, the team reviewed condition reports and system health reports to determine the overall health of the system, and determine if issues entered into the corrective action program were appropriately addressed.

b. Findings

No findings were identified.

.2.1.1 3 Reactor Core Isolation Cooling Turbine

a. Inspection Scope

The team inspected the Unit 1 RCIC system turbine to evaluate whether it was capable of meeting its design basis and operational requirements to support RCIC pump operation to provide cooling water to the reactor vessel under transient and postulated accident conditions. The team reviewed turbine lubricating oil cooler performance and the turbine governor control system including the inner speed loop and outer flow control loop to ensure the capability to meet design conditions. The team performed a walkdown of the turbine and associated equipment and interviewed system and design engineers to assess the material condition of the components. The team reviewed the TSs, UFSAR, and design calculations to determine the capability of the turbine to support the required speed ranges to provide pump flowrates, pressures and operating conditions for both the reactor vessel injection mode and condensate storage tank (CST) recirculation mode of operation. Additionally, the team evaluated whether the turbine control system would operate at worst case atmospheric temperatures. The RCIC turbine lubricating oil cooler inspection results and tube plugging limits were reviewed to verify that design basis heat removal requirements were satisfied. Finally, the team reviewed corrective action documents and system health reports to deter mine if there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

No findings were identified.

.2.1.1 4 Reactor Core Isolation Cooling Pump

a. Inspection Scope

The team inspected the Unit 1 RCIC pump to evaluate whether it was capable of meeting its design basis and operational requirements to provide cooling water to the reactor vessel under transient and postulated accident conditions. The team evaluated the ability of the RCIC pump to deliver the design and licensing bases flow rates at the maximum assumed reactor vessel backpressure. The net positive suction head (NPSH) for the RCIC pump was reviewed for maximum flow rates from the RCIC pump suction sources to verify that adequate NPSH margin was available at minimum water levels.

The team reviewed full flow testing and IST results to verify that the pump performance bounded the flow requirements in the safety analysis and to determine if Exelon had adequately evaluated pump degradation. The team performed a walkdown of the pump and interviewed system and design engineers to assess the material condition of the pump. Finally, the team reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess Exelon's ability to evaluate and correct problems.

b. Findings

No findings were identified.

a. Inspection Scope

The team reviewed the Unit 2 RHR full flow test return MOV, HV-051-F024A, to evaluate whether it was capable of meeting its design basis functions, including providing a flowpath to deliver cooling water to the suppression pool. The team reviewed the UFSAR, TSs, TS Bases, DBD, drawings, procedures, and the IST basis document to identify the performance requirements for the valve. The team reviewed MOV diagnostic test results and stroke-timing test data to verify acceptance criteria were met. The team evaluated whether the MOV safety functions, performance capability, and design margins were adequately monitored and maintained in accordance with Exelon's MOV program requirements. Additionally, the team reviewed the vendor manual and calibration records for the instruments that provide actuation signals to open or close the MOVs to verify the instruments were properly maintained to support valve actuation in accordance with the plant design.

The team verified that the MOV analyses used the maximum differential pressure expected across the valve during worst case operating conditions. The team reviewed supporting electrical calculations that established the degraded and maximum voltages at the MOV terminals to ensure the proper voltages were used in the MOV torque calculations. The design, operation, and maintenance of the valve were discussed with engineers to evaluate the valve's performance history, maintenance, and overall health.

The team also conducted a walkdown of the valve and associated equipment to assess the material condition of the equipment and to determine if the installed configuration was consistent with the plant drawings, procedures, and the design bases. Finally, the team

reviewed corrective action documents and system health reports to evaluate whether there were any adverse operating trends and to assess Exelon's ability to evaluate and

correct problems.

A-1 Attachment ATTACHMENT

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Exelon Personnel

J. Berg, System Engineer

J. Criczky, Mechanical Design Engineer

D. Cronomiz, Mechanical Design Engineer

R. George, Electrical Design Engineering Manager

G. Hunsberger, Electrical Engineer

T. Kuklensk, Procurement Engineer

M. Lui, Electrical Design Engineer

F. Michaels, Procurement Engineering Supervisor

R. Rowcotsky, Electrical Design Engineer

R. Schwab, Mechanical Design Engineer

G. Weiss, System Engineer

LIST OF ITEMS

OPENED, CLOSED AND DISCUSSED

Open and

Closed

05000352&353/2015007-01 NCV Failure to Verify Adequacy of EDG Voltage to Start Safety-Related Motors (Section 1R21.2.1.1)

05000352&353/2015007-02 NCV Failure to Verify Adequate Voltage Available for DC Equipment (Section 1R21.2.1.2)

LIST OF DOCUMENTS REVIEWED

Calculations and Engineering Evaluations

6300E.18, Load Study for Station Auxiliary Power System, Revision 21 6300E.19, Short Circuit Calculation with Computer Program TE502 and EA199, Revision 15

6300E.20, Voltage Regulation Study, Revisions 13 & 13A

6300E.23, Millstone Undervoltage Study, Revision 11

6380E.07, Diesel Generator Loading (Steady State), Revision 13 6380E.08, Diesel Generator Voltage Regulation Study, Revision 5 6900E.04, Ground Overcorrect Relays Selection and Coordination, Revision 2

6900E.09, Diesel Generator Protective Relay Settings, Revision 8

6900E.11, Load Center Circuit Breakers - Overcurrent Trip Devices, Revision 11

757303-28, Air Identified In 'A' and 'B' RHR Discharge Line of

HV-051-F016, 10/8/08

757303-31, Acceptance Criteria for Air Voids in ECCS Piping, Revision 2

757303-38, Acceptance Criteria for Air Voids in 6" RCIC Piping, 2/27/09

Attachment E51-C001-A-001, RCIC Pump Operation with High Temperature Process Fluid, Revision 0ECR 01-01233, GE

SIL 636 Non-Conservative Decay Heat Calculations, Revision 1

ECR 13-00166, ECR for Changes to RHRSW Min Flows to RHR HXs, Revision 0

ECR 14-00429, Actions to Obtain RHRSW Piping Margin, Revision 1

LE-0052, Class 1E Battery Duty Cycle Determination, Revision 15

LE-0069, Class 1E 125 Vdc System Voltage Analysis, Revision 4

LE-0104, DC MCC Manual Control Circuit Calculation, Revision 1

LE-053, Determine Acceptable Cable Size for Temporary Cable Jumpers Used during Battery Cell Maintenance/Testing, Revision 2

LG 07-00392, RCIC and Blackout Rule Calculations/Documentation, Revision 0

LG 10-00379, RCIC Turbine Governor Speed Limit Increase, Revision 1

LG 94-08553, Revisions of LGS EQ Packages per MOD P-00212, Revision 0

LG 94-08684, Revision of LGS EQ Packages per MOD P-00212, Revision 0

LG-11-00219, 118-00733 EDG Speed Switch X-GA-(1, 2) 0025A, B, C, and D, Revision 3

LG-11-00280, 114-80811 K-1 Contractor ARI for Diesel Generator IEE, Revision 0

LG-11-00336, EDG Speed Switch Replacement Support, Revision 0

LG-11-00479, Vendor Document Submittal for Processing to Record MGMT, Revision 0

LG-11-00526, As-Built/Reformat Calculation 6900E.09 to Current Requirements, Revision 0

LG-12-00013,

11480811 Revision of LG

ECR 11-00280 for K-1 Contactor EDG, Revision 0

LG-12-00168, Revision of K-1 Contactor ECR, Revision 1

LM-0060, SBO Analysis for the RCIC and HPCI Pump Rooms, Revision 2

LM-007, Diesel Generator Fuel Oil Consumption, Revision 6

LM-0379, Power Re-rate Evaluation, SBO Analysis, Revision 2

LM-041, Suppression Pool Heat-up during an SBO Event at LGS, Revision 1

LM-0627, ESW Pump Curves, Revision 4

LM-0640, RHR Heat Exchanger Minimum RHRSW Flow/Fouling Factor/Tube Plugging Limits for Shutdown Cooling, Revision 3

LM-0667, Diesel Generator Fuel Oil Tank Volume, Revision 0

LM-0668, Validation and Verification of Spreadsheet to Analyze Shell and Tube HXs, Revision 2

M-0638, RHR Heat Exchanger Minimum RHRSW Flow/Structural Evaluation for Tube Plugging, Revision 4 M20-6, Sizing of Diesel Oil Transfer Pumps, Revision 2 M-41-18, Allowable Leakage for Short-Term ADS Accumulator Tanks, Revision 3 M-49-03, RCIC Pump Discharge Pressure Drop, Revision 6

M-49-04, RCIC Pump Pressure, NPSH, Allowable Degradation and Pipe Volume, Revision 4

M-55-33, HPCI/RCIC Automatic Pump Suction Transfer Delay Timer, Revision 6 and 9

M-59-07, N2 Bottles Required for ADS, Revision 2 M-78-26, Battery Room Hydrogen Concentration, Revision 6 M-81-14, Standby Diesel Generator Building Heating and Cooling Loads, Revision 6

MEL-0116, Minimum ADS Air Supply Bottle Pressure, Revision 1

MEL-0121,

WS-5, Determine Heat Capacity Temperature Limit, Revision 8

P1-21-051, Evaluate Piping Stress for RHR Service Water Piping, Revision 12 Procurement Engineering Evaluation for 118-02684 SGTS Heater Control Panel, 3/4/14 Procurement Engineering Evaluation for 118-03494 Circuit Board Assembly, 8/12/14

Corrective Action Issue Reports

00319338

00394194

00556902

01090746

224950

248979

01250064

01250600

273125

274858

276176

01278797

01281903

297865

01304086

01313465

01313466

01313469

01313472

01324565

01324728

01328187

01332505

01332929

01339603

01341449

01343316

01354709

01355481

01355930

01365199

01371381

01372412

01380374

01380701

01386437

01388921

01390033

01390566

01395230

01409406

01422730

01426904

01490105

01493211

01496857

01534029

01534992

01552435

01611824

01629744

01635066

01635925

01647449

01647464

01659640

01661244

01684077

01684387

01691672

01694076

01697541

01699591

02345075

2384875

2390084

2401081

2432718

02434386

02434621

02441872

2447086

2448165

2478477

2483175

02487741

02487750

2488128

2489907

2490058

02490063

02496518

2496668

2498978

2512925

02515373*

2516273*

2518567*

2518991*

2519480*

2519542*

2520239*

2522625*

2523425*

2524185*

2524409*

2525370*

2525630*

2525662*

2526231*

2526233*

2535151*

A0664315 A0819255 A1483562

A1766118

A1820071

A1830903 A1867857 A1879692

A1902572

LG-94-00009

LG-94-00011

LG-94-00012

LG-94-00210

IR written as a result of this inspection

Design and Licensing Basis Documents

L-S-01A, Design Basis Document, Class 1E 125/250 Vdc System, Revision 9

L-S-03, Design Basis Document, High Pressure Coolant Injection System, Revision 20

L-S-04, Design Basis Document, Residual Heat Removal Service Water System, Revision 12

L-S-05, Design Basis Document, 4 kV System, Revision 10

L-S-07, Design Basis Document, Diesel G

enerator and Auxiliary Systems, Revision 15 L-S-09, Design Basis Document, Residual Heat Removal System, Revision 20 L-S-14, Design Basis Document, 480 Vac Load Center System, Revision 8 L-S-31, Design Basis Document, Automatic Depressurization System, Revision 4

L-S-39, Design Basis Document, Reactor Core Isolation Cooling System, Revision 13

L-S-41, Design Basis Document, Condensate Storage and Transfer System, Revision 6

L-S-42, Design Basis Document, Nuclear Boiler System, Revision 10 NUREG 0991, Supplement 3, SER Related to the Operation of LGS Units 1 and 2, 10/84 NUREG 0991, Supplements 1 - 9, SER Related to the Operation of LGS Units 1 and 2, 12/83

NUREG-0991, SER Related to the Operation of LGS, Units 1 and 2, August 1983

Technical Specifications and Bases, Unit 1, LGS, through Amendment 215

Technical Specifications and Bases, Unit 2, LGS, through Amendment 176

Updated Final Safety Evaluation Report, LGS, Revision 17

Drawings

11813380, Air Receiver, Revision 7

11870839, Air Start System, Revision 15

8031-M-12, Sht. 1, Residual Heat Removal Service Water, Revision 6, 62, and 85

8031-M-41, Sht. 2, Nuclear Boiler, Revision 60

8031-M-41, Sht. 3, Nuclear Boiler, Revision 53

8031-M-49, Reactor Core Isolation Cooling, Revision 52 8031-M-50, RCIC Pump/Turbine, Revision 11 8031-M-50, Sht. 1 and 3, RCIC Pump Turbine (Lube Oil and Control System), Revision 36 and 3

8031-M-51, Sht. 1, Residual Heat Removal, Revision 62

8031-M-51, Sht. 2, Residual Heat Removal, Revision 65

8031-M-52, Core Spray, Revision 18 8031-M-55, Sht. 1, High Pressure Coolant Injection, Revision 58 8031-M-56, Sht. 1, 3, and 4, HPCI Pump/Turbine, Revision 40, 1, and 2

8031-M-59, Sht. 1 Primary Containment Instrument Gas, Revision 38

8032-M-0372, Sht. 1, Condensate and Refueling Water Storage Tank Piping Plan, Revision 24

93-13377, 18"-300# Carbon Steel Swing Check Valve with Test Lever, Revision N E-1, Sht. 1, Single Line Diagram - Station, Revision 30

E-1, Single Line Diagram Station, Revision 30

E-15, 4 kV Safeguard Power System - 1 Unit, Revision 30

E-162, Safeguard Buses - D144/D244 Safeguard LC Transformer Breaker, 4 kV, Revision 13

E-164, Sht. 1, Safeguard Buses D11-14, D21-14 Generator Breakers, 4 kV, Revision 19

E-164, Sht. 2, Safeguard Buses D11-14, D21-24 Generator Breakers, 4 kV, Revision 27

E-28, D114, D124, D134, D144 Safeguard Load Centers, 440 Vac - 1 Unit, Revision 18 E-28, Single Line Meter and Relay Diagram D114, D124, D134, D144, Revision 18

E-30, Single Line Diagram Instrumentation AC System Unit 1, Revision 26

E-32, Sht. 1, Single Line Meter and Relay Diagram Uninterruptible AC System, Revision 55

E-33, Sht. 1, Single Line Meter and Relay Diagram 125/250 Vdc System, Revision 45 E-33, Sht. 2, Single Line Meter and Relay Diagram 125/250 Vdc System, Revision 47 E-360, Sht. 2, Schematic Diagram RHR Pumps, Revision 20

E-361, Sht. 1, Schematic Diagram RHR Service Water Pumps Common, Revision 28

E-361, Sht. 2, Schematic Diagram RHR Service Water Pumps Common, Revision 31

E-361, Sht. 3, Schematic Diagram RHR Service Water Pumps Common, Revision 25

E41-1040-E-031, HPCI/RCIC Test Return to CST, Revision 1 E-54, Sht. 1, MCC Load Tabulation, D134-C-B, D144-C-B - Control Enclosure, Safeguard MCC -440 Vac - Common, Revision 33 E-56, Sht. 2, MCC Load Tabulation, D114-D-G, D124-D-G, D134-D-G, D144-D-G - EDG Area, Safeguard MCC - 440V - 1 Unit, Revision 30 E-560, Schematic Diagram - EDG Diesel Oil Transfer Pumps - Units 1 and 2, Revision 5 E-81, Sht. 1, Schematic Meter & Relay Diagram - D13/D14 Safeguard Buses, 4 kV, Revision 20 E-85, Sht. 1, Schematic Meter & Relay Diagram - EDGs, 4 kV, Revision 19

E-85, Sht. 2, Schematic Meter & Relay Diagram - EDGs, 4 kV, Revision 11

E-88, D114, D124, D1345, D144 Safeguard Load Centers 440V, 1 Unit, Revision 7

HBB-103-1, Reactor Building Reactor Core Isolation Cooling, Unit 1, Revision 14

M1-E11-1040-E-005, Sht. 1, Elementary Diagram, Residual Heat Removal System, Revision 26 M1-E11-1040-E-006, Sht. 1, Elementary Diagram, Residual Heat Removal System, Revision 18 M-669-17, Differential Pressure Reactor Water Level Transmitter

LT-42-2N085B, Revision 1

M-71-48, Sht. 1, Schematic Engine Control - D14 Diesel Generator, Revision 30 M-71-48, Sht. 16, Schematic Engine Control - D14 Diesel Generator, Revision 0 M-71-48, Sht. 17, Schematic Engine Control - D14 Diesel Generator, Revision 3

M-71-48, Sht. 18, Schematic Engine Control - D14 Diesel Generator, Revision 1

M-71-48, Sht. 19, Schematic Engine Control - D14 Diesel Generator, Revision 0

M-71-48, Sht. 2, Schematic Engine Control - D14 Diesel Generator, Revision 32

M-71-48, Sht. 20, Schematic Engine Control - D14 Diesel Generator, Revision 1 M-71-65, Sht. 18, Control Schematic D14 Diesel Generator, Revision 2

SP-EBB-136-E2, Condensate Fill Line to 6"

EBB-136, Revision 5

Functional, Surveillance and Modification Acceptance Testing

BOP-UT-14-076, UT Data Report for

HBC-091-01 Location 1-4, 9/3/14

BOP-UT-14-123, UT Data Report for

HBC-091-01 Location 1-4, 10/9/14

BOP-UT-14-183, UT Data Report for

HBC-091-01 Location 1-4, 12/15/14

BOP-UT-15-097, UT Data Report for

HBC-091-01 Location 1-4, 3/24/15

Condensate Storage Tank 'A' and 'B' Level, for the period 7/18/13 - 7/1/15

HPCI Turbine and Pump Performance Data, for the period 6/20/00 - 5/6/15

IC-11-00328, Calibration Procedure for Bailey Type 701 Controller, performed 9/9/11

IC-11-00361, Calibration Procedure for RCIC EGM Speed Control, performed 9/8/11

IC-11-00713, Tuning of Inner Loop and Outer Loop RCIC Controls, performed 9/9/11

RCIC IST test data, for the period 6/8/05 - 3/23/15

RT-1-012-390-0, RHR Heat Exchanger Heat Transfer Performance Test, performed 12/22/14

RT-2-011-251-0, ESW Loop 'A' Flow Balance, performed 10/20/14

RT-2-012-390-1, 1A-E205 RHR Heat Exchanger Heat Transfer Test, performed 12/20/14

RT-4-049-641-1, U1 RCIC Air Accumulation Inspection, performed 5/26/15

RT-6-092-324-1, D14 EDG Overspeed Trip Test, performed 8/24/14

ST-1-008-900-1, CST and RWST Dike Inspection, performed 8/28/13

ST-2-041-475-1, SRV Position Indicating Sensors Functional Test, performed 4/4/14

ST-2-041-661-1, SRV Position Indicators Functional Test, performed 3/24/15

ST-2-049-601-1, RCIC - CST Level - Low Functional Test, performed 3/31/15

ST-2-049-602-1, RCIC - CST Level - Low Functional Test, performed 5/25/15

ST-2-088-320-1, Remote Shutdown System RCIC Operability Test, performed 6/4/13

ST-2-092-104-1, Division IV 4 kV SFGD Bus UV LSF/SAA, performed 3/21/14

ST-2-092-324-1, 4 kV D14 Bus UV Channel/Functional Test, performed 3/25/15, and 5/12/15

ST-2-107-371-1, RCIC - Keep Fill System High Point Venting, performed 9/15/13

ST-4-012-951-0, ISI Pressure Test of RHR Service Water Loop A, performed 10/2/14

ST-4-041-210-1, Main Steam Relief Valves Test, performed 4/1/14

ST-4-041-470-1, Main Steam SRV Solenoid and Air Operator Assemblies, performed 3/3/14

ST-4-095-951-1, 1A1D101 Battery Modified Performance Test, performed 3/10/04, 3/4/08, 3/3/12

ST-4-095-952-1, 1A2D101 Battery Modified Performance Test, performed 3/11/04, 3/5/08, 3/3/12

ST-4-095-971-1, 1A1D101 Safeguard Battery Service Test, performed 3/16/06, 4/2/10, 3/26/14

ST-4-095-972-1, 1A2D101 Safeguard Battery Service Test, performed 3/17/06, 4/2/10, 3/26/14

ST-4-LLR-006-1, 'K' Automatic Depressurization System Leak Test, performed 3/28/14

ST-6-008-250-1, Condensate Storage and Transfer System/Safeguard Fill Partial Flow Test (A Loop Core Spray), performed 7/29/10

ST-6-012-231-0, 'A' Loop RHRSW Pump, Valve & Flow Test, performed 4/3/15

ST-6-012-233-0, 'A' Loop RHRSW Pump Comprehensive Test, performed 12/30/14

ST-6-020-234-1, D14 EDG Fuel Oil Transfer Pump, Valve and Flow Test, performed 5/12/15

ST-6-049-230-1, RCIC Pump, Valve and Flow Test, performed 3/23/15

ST-6-049-231-1, RCIC Pump Comprehensive Test, performed 4/6/14

ST-6-051-231-1, 'A' RHR Pump, Valve, and Flow Test, performed 3/3/15

ST-6-055-231-2, HPCI Pump Comprehensive Test, performed 5/6/15

ST-6-059-201-1, PCIG Valve Test, performed 4/4/14

ST-6-092-114-1, D14

EDG 24-Hour Endurance Test, performed 3/25/15

ST-6-092-116-2, D22 EDG 4 kV Safeguard LOP LSF/SAA & Outage Testing, performed 4/21/15

ST-6-092-118-1, D14 EDG 4 kV Safeguard LOP LSF/SAA & Outage Testing, performed 2/27/12 and 3/22/14

ST-6-092-314-1, D14 EDG Slow Start Operability Test, performed 6/16/15, 4/10/15 and 5/12/15

ST-6-092-318-1, D14 EDG Fast Start Operability Test, performed 2/05/15

ST-6-092-324-1, D14 EDG LOCA/Load Reject Testing and Fast Start Operability Test, performed 7/24/13

ST-6-092-934-1, D14 EDG Governor and Voltage Regulator Post- Maintenance Testing, performed 10/22/12

ST-6-095-905-1, Safeguard Battery Weekly Inspection, performed 5/20/15

ST-6-095-911-1, 1A1D101/1A2D101 Safeguard Battery Quarterly Inspection, performed 3/6/15

ST-6-095-915-1, 1A1D101/1A2D101 Safeguard Battery Monthly Inspection, performed 5/6/15

ST-6-107-594-1, Weekly Surveillance Log, performed 5/23/15

Miscellaneous

731E769AD, Reactor Core Isolation Coolant System, Revision 11

E51-C001-J-7.1, Characteristic Curve Sheet, 6x6x10.5B, 12/1/71 Eddy Current Examination Report for 1A-E205 RHR Heat Exchanger, 4/8/10

EQ-LGS-018, EQ Target Rock Model 9867F SRV and Operator Assembly, Revision 0

ER-LG-321-1002, IST Program Plan, Revision 9

IST Pump Initial Baseline for 0C-P506, 3/2/13

IST Pump Re-Baseline for 0A-P506, 1/3/14 Letter, Anthony R. Pietrangelo (NEI) to Mark A. Satorius (NRC), Industry Initiative on Open Phase Condition, Project Number 689, 10/9/13 Letter, Exelon to NRC, Supplemental Response to Generic Letter 2008-01, 7/7/09

Letter, NRC to Limerick, RAI Regarding Generic Letter 2008-01, 1/12/10

Letter, R. Clark to G. Beck, Station Blackout Analysis, LGS, Units 1 and 2, 6/10/92

LGS 1 and 2, IST Basis, 3rd Ten Year Interval, 2/18/10 M-251, Design Specification for Nuclear Service Flexible Metal Hose, Revision 10

NEDC-31465, LGS Unit 1 EQ Report - Main Steam Safety Relief Valve Actuator, 8/10/87

NUPIC Audit Report on ATC Nuclear, 7/14/14

NUPIC Audit Report on Meggitt Safety Systems, 6/24/13

NUPIC Audit Report on Nuclear Logistics, 5/16/13 NUPIC Audit Report on Scientech Division of Curtiss Wright Flow Control, 12/29/14 Specification P-300, Design Specification for Piping, Revision 47

System Health Report, System P092 - EDG, Unit 1, 1/1/15 - 3/31/15

System Health Report, System P092B - 4 kV, Unit 1, 1/1/15 - 3/31/15

System Health Report, System P093 - 480 Vac, Unit 1, 1/1/15 - 3/31/15

Procedures

8M-092-012, 2.3 kV and 4 kV Power Circuit Breaker Overhaul, Revision 0

ARC-MCR-116, RCIC Pump Room Flood, Revision 2

ARC-MRC-008 D5, 10 Station Auxiliary Bus Open Phase, Revision 1

CY-LG-120-168, Spray Pond Treatment Activities, Revision 6

E-1, Loss of all AC Power, Revision 46

E-10/20, Loss of Offsite Power, Revision 53

E-D144, Loss of D144 Safeguard Load Center, Revision 10

IC-11-00328, Calibration Procedure for Bailey Type 701 Controller, Revision 4

IC-11-00713, Tuning of Inner Loop and Outer Loop RCIC Controls, Revision 2

IC-11-02002, EDG Voltage Regulators, Revision 18

IC-C-11-04067, Testing/Replacement of Agastat GP, TR, and 7000 Series Relays, Revision 10 M-092-004, Preventive Maintenance Procedure for Q-Listed 4 kV Air Circuit Breaker, Revision 8 M-093-004, 480 Vac MCC Breaker Assembly and Cubicle Terminal Maintenance, Revision 12

M-200-002, 2.3 kV and 4 kV Power Circuit Breaker Overhaul, Revision 8

MA-AA-716-230-1003, Thermography Program Guide, Revision 4

MA-AA-733-1001, Guidance for Check Valve General Visual Inspection, Revision 7 M-C-700-230, 480 Volt ABB/ITE Load Center Breaker Maintenance, Revision 15

NEM-MS-03.1, Piping Minimum Wall Thickness Calculation, Revision 5

OP-LG-103-102-1002, Strategies for Successful Transient Mitigation, Revision 18

RT-2-050-406-1, RCIC Turbine Exhaust Pressure - High; Channel 'A' Calibration Functional Test, Revision 6

RT-2-050-407-1, RCIC Turbine Exhaust Pressure - High; Channel 'E' Calibration Functional Test, Revision 7

RT-6-049-331-1, RCIC Overspeed Trip Test, Revision 6

RT-6-092-324-1, D14 EDG Overspeed Trip Test, Revision 29

S08.0.C, Transferring Water between the RWST and the CST, Revision 17

S08.9.A, Inspection of Condensate/Refuel Water Storage and Transfer System, Revision 15 S12.1.A, RHR Service Water System Startup, Revision 52 S12.2.A, Shutdown of RHR Service Water Pumps and System, Revision 34

S12.7.B, Cooling Tower or Spray Pond as a Heat Sink for RHRSW and ESW, Revision 20

S12.8.B, Chemical Treatment of ESW/RHRSW, Revision 35

S49.1.A, Normal RCIC Line-up for Automatic Operation, Revision 25

S49.3.A, RCIC Fill and Vent, Revision 33 S92.6.A, Transfer of a 4 kV Safeguard Bus from 101 Safeguard Feed to 201 Safeguard Feed and Vice Versa, Revision 19

SE-1, Remote Shutdown, Revision 71

SE-10, LOCA, Revision 59

SE-10-1, Breaker Reset Following LOCA, Revision 6

SE-17, Loss of Single Phase from Offsite Source, Revision 1

SE-4-1, Reactor Enclosure Flooding, Revision 9

SM-AA-300, Procurement Engineering Support Activities, Revision 6

SM-AA-300-1001, Procurement Engineering Process and Responsibilities, Revision 17

SP-220, Replacement of 'B' Loop RHRSW Return Piping During 2R13, Revision 0

ST-2-055-601-1, ECCS - CST Level - Low, Division 2 (HPCI) Functional Test, Revision 15

ST-2-092-104-1, Division IV 4 kV Safeguard Bus Undervoltage LSF/SAA, Revision 4

ST-2-092-324-1, 4 kV Emergency D14 Bus Undervoltage Channel/Functional Test, Revision 27

ST-6-012-231-0, 'A' Loop RHRSW Pump, Valve and Flow Test, Revision 66 and 68