ML15086A024

ANP-3300Q3NP, Revision 0 to Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature and Low Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1 (Non-Proprietary

ML15086A024
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Site:	Arkansas Nuclear
Issue date:	03/25/2015
From:	AREVA
To:	Office of Nuclear Reactor Regulation
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ML15086A019	List: 1CAN031504, Arkansas Nuclear One, Unit 1 - Responses to Request for Additional Information on Update of the Reactor Coolant System Pressure and Temperature and the Low Temperature Overpressure Protection System Limits 1CAN031504, Responses to Request for Additional Information on Update of the Reactor Coolant System Pressure and Temperature and the Low Temperature Overpressure Protection System Limits ML15086A024
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1CAN031504 ANP-3300Q3NP, Rev. 0
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Attachment 2 toI CAN031504 AREVA document ANP-3300Q3NP, Revision 0"Response to Request for Additional Information on Reactor Coolant SystemPressure/Temperature and Low Temperature Overpressure Protection System Limits to54 EFPY for Arkansas Nuclear One, Unit 1"NON-PROPRIETARY For Information OnlyAAREVAResponse to Request for Additional Information on Reactor Coolant SystemPressure/Temperature and LowTemperature Overpressure Protection System Limits to 54 EFPY for ArkansasNuclear One, Unit 1ANP-3300Q3NP Revision 0March 2015AREVA Inc.(c) 2015 AREVA Inc.

For Information OnlyCopyright

© 2015AREVA Inc.All Rights Reserved For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page iNature of ChangesSection(s)

Item or Page(s) Description and Justification 1 All Initial Issue For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page iiContentsPacie1.0 IN T R O D U C T IO N ..............................................................................................

42.0 REQUEST FOR ADDITIONAL INFORMATION

...............................................

62 .1 A dd itio nal R A I ......................................................................................

..62.1.1 Statem ent of Additional RAI .......................................................

62.1.2 Additional RAI Response:

...........................................................

72.1.3 ANO-1 LTOP (ERV Setpoint and Limit Curves)-R eference 5 ...............................................................................

102.2 B&W Plant LTOP Methodology

............................................................

132.3 LTOP Events-Operating Experience (References 10 and 11) .............

183.0 R E FE R E N C E S ...............................................................................................

20 For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page iiiNomenclature (If applicable)-update laterAcronymADAMSANO-1/ANO1 ARTCOMSERVOFft-lbIDK~tLARLTOPP-TRAIRCSRPV/RVRVCHTSWECDefinition Agencywide Documents Access and Management systemArkansas Nuclear One, Unit 1Adjusted Reference Temperature Cold Overpressure Mitigating SystemElectromatic Relief ValveDegree Fahrenheit foot-pound Inside DiameterThermal Stress Intensity FactorLicense Amendment RequestLow Temperature Overpressure Protection Pressure

-Temperature Request for Additional Information Reactor Coolant SystemReactor Pressure Vessel/ Reactor VesselReactor Vessel Closure HeadTechnical Specifications Westinghouse Electric Corporation For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page

41.0 INTRODUCTION

By application dated November 21, 2014, as supplemented by letters dated February 6and March 10, 2015 (Agencywide Documents Access and Management System(ADAMS Accession Nos. ML14330A249, ML15041A073, and ML15071A054, respectively-References 1-3), Entergy Operations, Inc., requested changes to theTechnical Specifications (TSs) for Arkansas Nuclear One, Unit No. 1 (ANO 1). Theproposed changes revise TS 3.4.3, "Reactor Coolant System (RCS) Pressure andTemperature (P/T) Limits, TS 3.4.9, "Pressurizer,"

TS 3.4.10, "Pressurizer SafetyValves,"

and TS 3.4.11, "Low Temperature Overpressure Protection."

to update thereactor coolant system (RCS) pressure and temperature (P/T) and low temperature overpressure protection (LTOP) system limits to 54 effective full power years (EFPYs),the end of the current period of extended operation.

Based on the U.S. Nuclear Regulatory Commission (NRC) staff review of theinformation provided by Entergy (ADAMS Accession Nos. ML14330A249-Reference 1),the NRC staff issued Entergy requests for additional information (RAIs); Entergyresponses to the RAIs are provided in References 2 and 3. On March 20, 2015 theNRC issued a subsequent RAI to Entergy (Reference

4) regarding the LTOP systemand the proposed revised electromatic relief valve (ERV) setpoint of 553.8 psig(Reference 4). Section 2.1 of this document provides the NRC RAI and the Entergyresponse.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 5The methodology used to establish LTOP limit curves (without location adjustments andinstrument errors) at 54 EFPY limits the maximum pressure in the vessel to 100% of theisothermal P-T limit curves determined to satisfy equation (1) of ASME Section XI, 2001Edition with 2002 Addenda, Appendix G-2215 (References 5 and 6). The previous 21and 32 EFPY the LTOP limit curves (without location adjustments and instrument errors) were provided as 110% of the isothermal P-T limit curves in accordance withASME Code Case N-514 (Reference 7). The methodologies used to establish the ERVLTOP setpoint and LTOP limit curves at 54 EFPY are provided in Sections 2.1 and 2.2of this document.

Information considered proprietary to AREVA in the following discussions is enclosed inbrackets

[ ].

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 62.0 REQUEST FOR ADDITIONAL INFORMATION A Draft request for additional information (RAI) regarding the LTOP system wasdiscussed between the NRC and Entergy on March 19, 2015 and the NRC issued thefinal RAI on March 20, 2015 (Reference 4). The RAI is presented in Section 2.1.1 andthe Entergy response is provided in Section 2.1.2. The methodologies used to establish the LTOP pressure limit (i.e., ERV setpoint of 553.8 psig), reported in Reference 1, andLTOP limit curves at 54 EFPY (Section 2.1.2, Figure 1), which are more limiting than theP-T curves for RCS temperatures less than the LTOP enable temperature of 259 'F, areprovided in Sections 2.1 and 2.2 below.2.1 Additional RAIThe NRC RAI regarding the change in the ERV LTOP setpoint was issued on March 20,2015 (Reference 4).2.1.1 Statement of Additional RAI"The proposed revised electromatic relief valve (ERV) setpoint is 553.8 psig [pounds persquare inch gauge]. The American Society of Mechanical Engineers Boiler andPressure Vessel Code (ASME Code),Section XI, Appendix G, Paragraph G-2215states that low temperature overpressure protection (LTOP) systems shall limit themaximum pressure of the vessel to 100% of the pressure determined to satisfyEquation 1 (e.g., the pressure for normal operation heatup or cooldown transients).

Theminimum allowable pressure for ANO-1 is 508 psig for the 90 deg/hour heatup transient (Table 7-1 of ANP-3300) and 513 psig for the cooldown transient (Table 7-3 of ANP-3300). Please explain how the ERV setpoint meets the ASME Code, Section XIrequirements, since the setpoint is greater than the minimum allowable pressure."

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 72.1.2 Additional RAI Response:

The 54 EFPY LTOP relief valve setpoint (553.8 psig) is based on 100% of the fracturemechanics ASME Section'XI, Appendix G, pressure-temperature (P-T) limits forisothermal conditions (Reference 5). Isothermal conditions are defined as an RCStemperature during heatup or cooldown in which there is no through-wall temperature gradient within the RV shell and closure head. The ERV setpoint is the lowest location(i.e., RV beltline, RV nozzle, and RV closure head) corrected RCS pressure based onisothermal conditions.

The ERV setpoint is applicable from 60 OF to the enabletemperature of 259 OF.The ERV LTOP setpoint value is revised from 460 psig at 32 EFPY to 553.8 psig at 54EFPY. The 54 EFPY P-T and LTOP P-T limits (i.e., P-T curves that apply at and belowthe LTOP enable temperature of 259 OF) were determined using the methodology contained in ASME Section XI, Appendix G 2001 Edition through 2002 Addenda.

The32 EFPY P-T and LTOP P-T limits were determined using the methodology contained inASME Section XI, Appendix G, 1998 Edition, Supplemented by Code Case N-514 forLTOP (Reference 7).The 2001 ASME Section Xl Code permits the use of the higher Kic fracture toughness curve and utilizes the new methodology for calculating the stress intensity factors forpressure and radial thermal gradient.

In addition, the Adjusted Reference Temperature (ART) for the limiting location at 54 EFPY is an upper shell plate material that has avalue of 180°F at the 1/4t postulated flaw depth versus a beltline weld at 32 EFPY withan ART of 212 OF at the 1/4t location (Reference 7). The use of BAW-2308 for theLinde 80 beltline resulted in the reduction of the beltline weld ART such that platematerial is controlling at 54 EFPY. Although, the 32 EFPY LTOP setpoint (Reference

14) was based on a slightly higher isothermal Appendix G curve (110% versus 100% forthe 54 EFPY LTOP curves),

it utilized the older ASME Section XI, Appendix G Code(1989 Edition) for calculating the stress intensity

factors, utilized a lower bound Kiafracture toughness curve and included a more limiting 1/4t ART of 212 OF. Therefore, the ERV enable pressure at 54 EFPY is increased relative to 32 EFPY.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Paqe 8Isothermal conditions are used for LTOP (both ERV setpoint and LTOP P-T limits)because the postulated pressurization events at low temperatures will occur at or veryclose to a steady state condition.

LTOP events occur as the result of equipment malfunction or operator error that results in mass or energy addition to the reactorcoolant system. The limiting postulated LTOP event for a B&W plant is failure of amakeup control valve (i.e., mass addition event and not an energy addition event) thatresults in an RCS pressurization rate of approximately 20 to 30 psi/minute (Reference 5,Figure 5-1), depending on the pressurizer level at the start of the event.The LTOP P-T limits are obtained by reducing the isothermal P-T limits generated inaccordance with ASME Section XI, G-2215, by the expected pressurization of the RCSdue to mass addition over a 10-minute operator action interval based on the limitingLTOP event (i.e., failed open makeup valve). The contribution to RCS pressurization byenergy addition over a 10-minute interval is negligible compared to makeup massaddition.

The LTOP P-T limit curves are lower than the HU/CD P-T curves reported inFigures 7-1 through 7-3 of ANP-3300, Revision 1, and are imposed as operating restrictions by ANO-1 during heatup and cooldown at temperatures at and below theLTOP enable temperature.

The ERV setpoint of (553.8 psig) ensures that 100% of thesteady state fracture mechanics ASME Section XI, Appendix G, pressure-temperature (P-T) limits for isothermal conditions will not be exceeded at and below the LTOPenable temperature (259 'F).Because of restrictions that preclude water-solid operation of the pressurizer (i.e., asteam or nitrogen bubble is maintained with the reactor vessel head on); the B&W plantdesign is not likely to exceed Appendix G limits due to LTOP based on review ofoperating data in Section 2.3. In addition, use of isothermal conditions for LTOP isconsistent with the methodology used by WEC for evaluation of Cold Overpressure Mitigating System (COMS), Reference

9.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Paqe 9Therefore, the ASME Section XI Appendix G derived isothermal limits are applicable and used in the development of the LTOP set-point.

The ASME Section Xl Appendix Gisothermal' limits are derived using Paragraph G-2215, Equation

1. Since the ERVsetpoint is equal to the minimum allowable pressure for isothermal conditions, thesetpoint meets the ASME Code,Section XI requirements.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Paae 10-2.1.3 ANO-1 LTOP (ERV Setpoint and Limit Curves)-Reference 5

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 11 For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Pacie 12LFigure 1 -LTOP Pressure-Temperature Limits Fur Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 132.2 B&W Plant LTOP Methodology The methodology applicable to B&W plants for establishment of LTOP P-T limits fortemperatures at and below the LTOP enable temperature is provided below. The LTOPmethodology includes the following elements.

• Definition of reactor vessel pressure limit* Definition of enable temperature

" Definition of LTOP transients

• Consequences of LTOP events" Definition of methods to protect the reactor vessel pressure limitDefinition of the Reactor Vessel Pressure Limit for LTOPPer ASME Section XI, Appendix G, 2001 edition through 2002 Addenda, LTOP systemsare required to limit the maximum pressure in the vessel to 100% of the pressuredetermined to satisfy the Equation 1 limits on fracture toughness.

Thus, thecalculational methodology is identical to those used in the Appendix G calculations.

The use of steady state temperatures (also known as isothermal),

rather than thetransient resulting from technical specification heatup and cooldown limits is based onthe likelihood that LTOP events occur during steady-state operations.

The use ofsteady state or isothermal condition as an LTOP initiation event is consistent with theapproach used by a recent P-T submittal by another B&W plant (References 12 and 13)and WEC-designed plants (Reference 9).In the past, the use of a 10% increase in pressure above the Appendix G limit wasjustified by ASME Code Case N-514. The Code Case allowed the use of 110% of theASME Section XI, Appendix G RCS pressure limits, when determining LTOP limits.This code case is no longer applicable, and 100% of the ASME Section XI, Appendix GRCS pressure limit, is now used as the limit.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 14Definition of Enable Temperature ASME Section XI, Appendix G, Article G-2215 defines the LTOP enable temperature.

For the ANO One Unit 1 plant, the RTNDT of the limiting material is 180 'F. The RTNDTplus 50 'F value corresponds to 230 'F. The maximum transient condition fluidtemperature occurs during heatup at 90 °F/hour when the maximum temperature difference of 290F is calculated between the metal temperature (at RTNDT plus 50 'F or230 'F) and the fluid temperature.

This results in an enable temperature of 230 'F plus29 'F or 259 'F.Definition of LTOP Transients LTOP events occur as a result of equipment malfunction or operator error that results inmass or energy addition to the reactor coolant system. In the B&W plant operating history up to 2015, only once have the technical specification Appendix G limits beenviolated due to an LTOP event. Because of restrictions that preclude water-solid operation of the pressurizer (i.e., a steam or nitrogen bubble is maintained with thereactor vessel head on); the B&W plant design is not likely to exceed Appendix G limitsdue to LTOP.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 15In the B&W design, mass can be injected into the system through:1. the four HPI nozzles (one or two of which also serve as normal makeup);2. the core flood nozzles through which the core flood tank system, decay heatremoval system, and low pressure injection system (LPI) can provide addedinventory; and3. the pressurizer spray nozzle via HPI, LPI, or the nitrogen addition system.Energy can be added to the RCS via:1. failure of the decay heat removal system;2. actuation of the pressurizer heaters; and3. reactor coolant pumps.As a result, the following transients were postulated and evaluated for their potential toincrease reactor vessel pressure:

1. Erroneous actuation of the High Pressure Injection (HPI) system2. Erroneous opening of the core flood tank discharge valve3. Erroneous addition of nitrogen to the pressurizer

4. Makeup control valve (makeup to the RCS) fails full open5. All pressurizer heaters erroneously energized

6. Temporary loss of the Decay Heat Removal System's (DHRS) capability toremove decay heat from the RCS7. Thermal expansion of the RCS after starting an RC pump due to stored thermalenergy in the steam generator For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 16Consequences of LTOP EventsThe postulated LTOP events were analyzed to determine the rate of RCS pressureincrease and/or the total amount of pressure increase that the system wouldexperience.

A stand-alone thermal-hydraulic model of the pressurizer was used forthese predictions.

Capabilities to model RCS inventory increases (e.g., makeup, HPI),inventory decreases (e.g., letdown),

RCS expansion, and pressurizer heaters wereincluded.

A range of initial pressures and pressurizer levels were applied so that thepressurization rates could be applied to different initial P-T operating conditions.

A briefsummary of each transient response is provided below.1. Erroneous actuation of the High Pressure Injection (HPI) system -this eventwould be the most limiting LTOP transient.

However, HPI actuation results in avery .rapid pressurization of the RCS and precludes achieving the necessary 10 minutes for operator action. Thus, this event is prevented below the LTOPenable temperature through plant procedures.

2. Erroneous opening of the core flood tank discharge valve -this event isprecluded by closing and locking out the breakers of the motor operated blockvalves before the RCS pressure decreases below the CFT pressure (600 psig).This will occur prior to cooling below the LTOP enable temperature.

3. Erroneous addition of nitrogen to the pressurizer

-this event cannot over-pressurize the RCS because of plant equipment that regulates the nitrogenpressure to 150 psig (i.e., pressure regulator and relief valves).4. Makeup control valve (makeup to the RCS) fails full open -this event results in apressurization rate of 20 to 30 psi/minute and is the most limiting of the remaining LTOP events.5. All pressurizer heaters erroneously energized

-this event is a slow transient (9 to12 psi/minute) and is bounded by the failed makeup control valve event.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 176. Temporary loss of the Decay Heat Removal System's (DHRS) capability toremove decay heat from the RCS -this event is a slow transient (7 psi/minute) and is bounded by the failed makeup control valve event.7. Thermal expansion of the RCS after starting an RC pump due to stored thermalenergy in the steam generator

-this event results in a finite increase in pressurethat is less than the margin between the Appendix G and LTOP limits. Becauseof the presence of a pressurizer bubble, this event is much less severe than atother PWRs.In summary, the most limiting, credible event is the failed open makeup control valve.Because of system design differences, the plant response is sensitive to the makeuppump head-capacity curve and system resistance.

This requires each plant to evaluatea plant specific response.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 18Definition of Methods to Protect the Reactor Vessel Pressure LimitIn general, each plant is equipped with either: (1) a dual setpoint pilot operated reliefvalve that is set below the LTOP limit, or (2) an additional relief valve (e.g., decay heatremoval system relief valve) that is also set below the LTOP limit. In. the event of reliefvalve failure, plant operation is limited (i.e., combination of operating

pressure, pressurizer level) such that, in the event of the most limiting LTOP event, failed openmakeup control valve, either: (1) ten minutes are available between the time thepressure-temperature operating limits are exceeded and the LTOP limits are violated, thus, providing adequate time for the operator to terminate the event, or (2) theavailable makeup tank volume would be exceeded and thus terminate the event beforethe LTOP limit is violated.

2.3 LTOP Events-Operating Experience Low temperature pressurization events became an issue for the operating plants inearly 1976 when the NRC conducted a review of reported pressure transients that hadoccurred.

For each of the 30 events identified at the time, the Technical Specification pressure-temperature limits were exceeded.

These overpressurization events, whichoccurred mostly during startup and shutdown operations when the RCS was in a watersolid condition, were caused either by equipment malfunction, procedural deficiencies, or incorrect operator action. (Reference 10)For the B&W-designed plants, there has been only one instance of exceeding theTechnical Specification pressure limit. This single event, identified as one of the30 events by the NRC review, occurred at Oconee Unit 1 in 1972, five months beforeinitial criticality.

This event was not a transient, but was a planned operation as part ofthe zero power physics testing procedure.

B&W-designed plants have a much lowerpotential for startup and cooldown overpressure transients than other PWR's and adisproportionately lower frequency of occurrence for such events.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 19From 1979 through 1987 there have been 61 LTOP events that have occurred inWestinghouse plants. The LTOP event type contributions are discussed in EPRI ReportTR-103084-.T2 and a summary of each of these LTOP events is provided in Appendix Aof the report (Reference 11).An informal review of the INPO operating experience (OE) database for LTOP eventsthat occurred between 1995 to the present date revealed at least 9 additional LTOPevents that occurred at Combustion Engineering and Westinghouse designed plants.

For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additional Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Page 2

03.0 REFERENCES

1. License Amendment Request Update the Reactor Coolant SystemPressure and Temperature and the Low Temperature Overpressure Protection System Limits, Arkansas Nuclear One, Unit 1, AdamsAccession Numbers ML14330A246, ML14330A249, ML14330A250, November 21, 20142. Responses to Request for Additional Information Update the ReactorCoolant System Pressure and Temperature and the Low Temperature Overpressure Protection System Limits, Adams Accession NumberML15041A073, February 6, 20153. Responses to Request for Additional Information Update the ReactorCoolant System Pressure and Temperature and the Low Temperature Overpressure Protection System Limits Arkansas Nuclear One, AdamsAccession Number 15071A054, March 10, 20154. E-mail from NRC Singal, Balwant to Bob Clark, March 20, 2015, 11:57a.m., FW: Arkansas Nuclear One, Unit No. 1, Request for Additional Information (Second Round) -License Amendment Request (TACMF5292)5.[6.[7.[8. Not used For Information OnlyAREVA Inc. ANP-3300Q3NP Revision 0Response to Request for Additibnal Information on Reactor Coolant System Pressure/Temperature andLow Temperature Overpressure Protection System Limits to 54 EFPY for Arkansas Nuclear One, Unit 1Pagqe 219. WCAP-14040-A, Revision 4,Methodology Used to Develop ColdOverpressure Mitigating System Setpoints and RCS Heatup andCooldown Limit Curves, May 2004, Adams Accession NumberML050120209 10.[11. EPRI Report TR-1 03084-T2, System Aspects of Reactor Pressure VesselIntegrity, Final Report, November 199312. Duke Energy Carolinas, LLC Oconee Nuclear Station (ONS), Units 1, 2,and 3, Docket Numbers 50-269, 50-270, and 50-287, License Amendment Request to Update Pressure-Temperature Limit Curves, LicenseAmendment Request (LAR) No. 2012-10, Adams Accession NumberML13058A059, Enclosure 2, ANP-312713.NRC SER, OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3,ISSUANCE OF AMENDMENTS REGARDING REVISED PRESSURE-TEMPERATURE LIMITS (TAC NOS. MF0763, MF0764, AND MF0765),ADAM Accession Number ML14041A093, February 27, 201414.[I