ML15029A454

Grand Gulf, Unit 1, Response to Item 20 Request for Additional Information Regarding Maximum Extended Load Line Limit Plus Amendment Request, Dated 5/19/2014

ML15029A454
Person / Time
Site:	Grand Gulf
Issue date:	01/20/2015
From:	Kevin Mulligan Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2014/00088, TAC MF2798
Download: ML15029A454 (36)

Text

{{#Wiki_filter:SEntergy'Entergy Operations, Inc.P. O. Box 756Port Gibson, MS 39150Kevin MulliganSite Vice PresidentGrand Gulf Nuclear StationTel. (601) 437-7400Attachment 1 contains PROPRIETARY informationGNRO-2014/00088January 20, 2015U.S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, DC 20555-0001SUBJECT:REFERENCES:Response to Item 20 Request for Additional Information RegardingMaximum Extended Load Line Limit Plus Amendment Request, dated5/19/2014.Grand Gulf Nuclear Station, Unit 1Docket No. 50-416License No. NPF-291 Electronic Request for Additional Information Regarding "MaximumExtended Load Line Limit Plus" Amendment Request Dated 5/19/2014(TAC MF2798)2 Entergy Letter, "Maximum Extended Load Line Limit Analysis Plus(MELLLA+) License Amendment Request," GNRO-2013/00012, datedSeptember 25, 2013 (ADAMS Accession No. ML13269A140).3 Entergy Letter, "Response to Request for Additional InformationRegarding Maximum Extended Load Line Limit Plus AmendmentRequest, dated 8/27/14 (ADAMS Accession No. ML 14239A184).Dear Sir or Madam:Entergy Operations, Inc. is providing in the Attachments a response to the Reference 1 Item 20Request for Additional Information (RAI). Item 20 discusses Code-to-Code Comparisons. Allother items with regard to this RAI were previously answered via Reference 3. All figures, alongwith their tabulated data will also be provided on a CD enclosed with this letter.Attachment 1 contains proprietary information as defined by 10 CFR 2.390. General Electric-Hitachi (GEH), as the owner of the proprietary information, has executed the attached affidavit,which identifies that the attached proprietary information has been handled and classified asproprietary, is customarily held in confidence, and has been withheld from public disclosure. Theproprietary information was provided to Entergy in a GEH transmittal that is referenced by theaffidavit. The proprietary information has been faithfully reproduced in the attached such thatthe affidavit remains applicable. GEH hereby requests that the attached proprietary informationbe withheld from public disclosure in accordance with the provisions of 10 CFR 2.390 and 9.17.Information that is not considered proprietary is provided in Attachment 2. Attachment 3When Attachment I is removed from this letter, the entire document is Do.)NON-PROPRIETARY pt GNRO-2014-00088Page 2 of 2contains the affidavit which identifies that the information contained in Attachment 1 has beenhandled and classified as proprietary to GEH. On behalf of GEH, Entergy requests thatAttachment 1 be withheld from public disclosure in accordance with 10 CFR 2.390(b)(1).This letter contains no new commitments. If you have any questions or require additionalinformation, please contact Mr. James Nadeau at 601-437-2103.I declare under penalty of perjury that the foregoing is true and correct; executed onJanuary 20, 2015.Sincerely,KJM/tmcAttachments:1 AEP-647 Proprietary Responses to Item 20 of the Request for Additional Information2 AEP-647 Non-Proprietary Responses to Item 20 of the Request for AdditionalInformation3 GEH Affidavit for Attachment 1Enclosure:1 CD of Figures with Tabulated Datacc: with AttachmentsU.S. Nuclear Regulatory CommissionATTN: Mr. Marc L. DapasRegional Administrator, Region IV1600 East Lamar BoulevardArlington, TX 76011-4511U.S. Nuclear Regulatory CommissionATTN: Mr. A. Wang, NRR/DORLMail Stop OWFN/8 G14Washington, DC 20555-0001NRC Senior Resident InspectorGrand Gulf Nuclear StationPort Gibson, MS 39150State Health OfficerMississippi Department of HealthP. 0. Box 1700Jackson, MS 39215-1700

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2 toGNRO-2014/00088AEP-647 Non-Proprietary Responses to Item 20 of the Request for Additional InformationNON-PROPRIETARY NOTICEThis is a non-proprietary version of Attachment 1 which has the proprietary informationremoved. Portions of the document that have been removed are indicated by an open andclosed bracket as shown here [[ fl.

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2 toGNRO-2014/00088Non-Proprietary InformationPage 1 of 28RAI 20.0 CODE-TO-CODE COMPARISONEvents leading to reactor instabilities cause oscillations in PCT over time. The magnitude ofthese oscillations has been seen to vary from code to code. Analyses completed by the Office ofNuclear Regulatory Research at the NRC have documented TRACE results for ATWS-I thatlead to reactor instabilities with high PCT.1. Develop a synonymous model using TRACG.2. Compare TRACG results with TRACE results for an ATWS-I turbine trip with 100%bypass event initiated from 120% Originally Licensed Thermal Power (OLTP) and 85%reactor core flow at beginning of cycle and the peak hot excess point in the cycle.Provide discussion of differences between the two calculation results, in particular,wherever possible, identify candidate constitutive models, modeling procedures, inputassumptions, or other factors that contribute to the differences.3. Provide results in tabular form and in plots of the same two cases in RAI 20.2 above(ATWS-I turbine trip with 100% bypass event initiated from 120% Originally LicensedThermal Power (OLTP) and 85% reactor core flow at beginning of cycle and the peak hotexcess point in the cycle) using a constant Train of 900K.GEH Response1. A synonymous TRACG model to the TRACE model used by the NRC has beendeveloped. The TRACG and TRACE models were developed from the same TRACGbasedeck (as referenced in Reference 20-1). The input and modeling assumptions used inthe TRACE analysis are not applicable to any specific nuclear plant; however areadequate for the intended purpose. Comparisons between key parameters are provided inTable 20-1. In some cases the modeling inputs and assumptions are different and moreconservative than standard GEH ATWSI assumptions; however, the changes arereasonable and appropriate given the purpose of these comparisons. All TRACG caseswere performed with the quench model turned on consistent with GEH ATWSImodeling.Table 20-1 -Input Comparison Between TRACE and TRACGTRACE TRACG.:. NotesVessel Radial Rings 3 3

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2 toGNRO-2014/00088Non-Proprietary InformationPage 2 of 28_________ _ :TRACE TRACG NotesChannel Groups 382 382 Channel group locations are consistentwith Figure 2.5 of Reference 20-1. It isnoted that this TRACE groupingassumes a specific harmonic plane ofsymmetry.Hot Rod Single Rod Single Rod Consistent with Table 2.1 of Referencewith with 20-1relative rod relative rodpower power(CPOWR) (CPOWR)of 1.2 of 1.2Recirculation Pump 1095 psig 1095 psigTrip (RPT) SetpointStandby Liquid Upper UpperControl System Plenum Plenum(SLCS) LocationSLCS Timing Ramp up Ramp up Section 4.1 of Reference 20-1.from 120 to from 120 to180 seconds 180after the secondsturbine trip after theturbine tripTrain -725 K -725 K TRACG cases are performed at two-900 K -900 K exposures, with a low Tmin and with ahigh Tmin. 725 K is an estimated valuefrom TRACE used for TRACGpurposes.Feedwater (FW) Reduce to Reduce to Consistent with comment on page A-44Temperature 11 OF with 1 OF with of Reference 20-1Reduction 75-second 75-secondlag lagWater Level 110 seconds 110 Section 4.1 of Reference 20-1Reduction Initiation after turbine secondsTime trip afterturbine tripWater Level 180 seconds 180 Section 4.1 of Reference 20-1. It isReduction Duration seconds noted that this rate in level reduction isTime slower (more conservative) than typicalplant response.Initial Water Level 14.9 m 14.9 m The TRACE initial water level increasesControl After above and is maintained higher than theTurbine Trip (before initial level; therefore, TRACG is110 seconds) modeled similarly for consistency.

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2 toGNRO-2014/00088Non-Proprietary InformationPage 3 of 28TRACE TRACG NotesPressure Control Constant Turbine The TRACG normal pressure regulatorpressure of pressure setpoint is adjusted to result in a similar924 psi at inlet dome pressure response compared toturbine first controlled TRACE for representative steam flows.stage inlet as a Some differences in the modelingfunction of produce some differences in the results.steam flow.Bypass Capacity and 100% 100% Both models assume 100% bypassTiming Bypass Bypass capacity, but they open at different ratesCapacity. Capacity. based on differences in inputValves open Valves are assumptions. These differences onlylinearly controlled affect the initial part of the transient.from 0.0 to per the TRACE results in higher peak pressure.1.0 seconds bypass Long-term instabilities are not affected.controlsystem2. Figures 20-1 through 20-18 show the comparison for key parameters with Tminapproximately equal to 725 K: Figures 20-1 through 20-9 shows the results for Peak HotExcess (PHE), and Figures 20-10 through 20-18 shows Beginning of Cycle (BOC)results. All figures, along with the tabulated data, are also included in files Plots-Compare-BOC-Tmin725.xlsx and Plots-Compare-PHE-Tmin725.xlsx, which arelocated on a CD enclosed with this letter. Considering the differences in codes, theoverall response matches well. Power and steam flow in both cases level off around 50%power, and core flow around 25% before the level reduction occurs; however, theTRACE core flow is slightly lower from about 10 to 120 seconds. Dome pressure levelsaround 955 psia for both cases. The FW temperature drop is nearly identical. The lowerpredicted core flow in TRACE results in higher inlet subcooling.The main difference in the results is the timing of oscillations. In TRACG, theseoscillations commence [[]] but it is noted that the TRACG results are more conservative. [[3. Both TRACG and TRACE models were re-performed with higher Tmin values around900 K. The results are very similar to the results discussed in #2 with the exception that[[]] It is concluded that the Tmin value is an important parameter to predict

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2 toGNRO-2014/00088Non-Proprietary InformationPage 3 of 28..TRACE TRACG' Notes...Pressure Control Constant Turbine The TRACG normal pressure regulatorpressure of pressure setpoint is adjusted to result in a similar924 psi at inlet dome pressure response compared toturbine first controlled TRACE for representative steam flows.stage inlet as a Some differences in the modelingfunction of produce some differences in the results.steam flow.Bypass Capacity and 100% 100% Both models assume 100% bypassTiming Bypass Bypass capacity, but they open at different ratesCapacity. Capacity. based on differences in inputValves open Valves are assumptions. These differences onlylinearly controlled affect the initial part of the transient.from 0.0 to per the TRACE results in higher peak pressure.1.0 seconds bypass Long-term instabilities are not affected.controlI system2. Figures 20-1 through 20-18 show the comparison for key parameters with Tminapproximately equal to 725 K: Figures 20-1 through 20-9 shows the results for Peak HotExcess (PHE), and Figures 20-10 through 20-18 shows Beginning of Cycle (BOC)results. All figures, along with the tabulated data, are also included in files Plots-Compare-BOC-Tmin725.xlsx and Plots-Compare-PHE-Tmin725.xlsx, which arelocated on a separate CD. Considering the differences in codes, the overall responsematches well. Power and steam flow in both cases level off around 50% power, and coreflow around 25% before the level reduction occurs; however, the TRACE core flow isslightly lower from about 10 to 120 seconds. Dome pressure levels around 955 psia forboth cases. The FW temperature drop is nearly identical. The lower predicted core flowin TRACE results in higher inlet subcooling.The main difference in the results is the timing of oscillations. In TRACG, theseoscillations commence [[]] but it is noted that the TRACG results are more conservative. [[]]3. Both TRACG and TRACE models were re-performed with higher Tmin values around900 K. The results are very similar to the results discussed in #2 with the exception that]] It is concluded that the Tmin value is an important parameter to predict

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2 toGNRO-2014/00088Non-Proprietary InformationPage 4 of 28fuel cladding temperatures during an ATWSI event. Figures 20-19 through 20-36 showthe comparison for key parameters: Figures 20-19 through 20-27 shows the results forPHE, and Figures 20-28 through 20-36 shows BOC results. All figures, along with thetabulated data, are also included in files Plots-Compare-BOC-Tmin900.xlsx and Plots-Compare-PHE-Tmin900.xlsx, which are located on a separate CD.Figure 20-0 shows a comparison of the calculated PCTs for both Tmjn values.Figure 20-0. PCT Comparison, PHEI]]References20-1 BNL-97068-2012, "Brookhaven National Laboratory -BWR Anticipated TransientsWithout Scram in the MELLLA+ Expanded operating Domain," March 30, 2012.

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2 toGNRO-2014/00088Non-Proprietary InformationPage 5 of 28ATWSI-TTWBP PLOTSTmin = 725 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 6 of 28Figure 20-1. Reactor Power, Tmin = 725 K, PHE (1)Figure 20-2. Core Flow, T.,i = 725 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationFigure 20-3. Dome Pressure, T.,. = 725 K, PHEPage 7 of 28Figure 20-4. Maximum Peak Clad Temperature, TW. = 725 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 8 of 28Figure 20-5. Downcomer Level, Tj,, = 725 K, PHEFigure 20-6. Feedwater Flow, Tmin 725 K, PHE[[1]

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2 toGNRO-2014/00088[[Non-Proprietary InformationFigure 20-7. Steamline Flow, Tmi. = 725 K, PHEPage 9 of 28FeFigure 20-8. Feedwater Temperature, Tmin = 725 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 10 of 28Figure 20-9. Core Inlet Subcooling, Tmjn = 725 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 11 of 28ATWSI-TTWBP PLOTSTmin -725 K, BOC

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2 toG N RO-2014/00088Non-Proprietary InformationPage 12 of 28[[Figure 20-10. Reactor Power, Twn = 725 K, BOCFFFigure 20-11. Core Flow, Train= 725 K, BOC[II

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2 toGNRO-2014/00088Non-Proprietary InformationPage 13 of 28[[Figure 20-12. Dome Pressure, Tmin = 725 K, BOCFigure 20-13. Maximum Peak Clad Temperature, Tmin, 725 K, BOC[[

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2 to Non-Proprietary InformationGNRO-2014/00088Figure 20-14. Downcomer Level, Tmin = 725 K, BOC[[Page 14 of 28FFFigure 20-15. Feedwater Flow, n= 725 K, BOC[[

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2 toGNRO-2014/00088Non-Proprietary InformationPage 15 of 28Figure 20-16. Steamline Flow, Tmin = 725 K, BOCFigure 20-17. Feedwater Temperature, Tminz 725 K, BOC

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2 toGNRO-2014/00088Non-Proprietary InformationPage 16 of 28Figure 20-18. Core Inlet Subcooling, Train = 725 K, BOC[[

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2 toGNRO-2014/00088Non-Proprietary InformationPage 17 of 28ATWSI-TTWBP PLOTSTmin = 900 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 18 of 28Figure 20-19. Reactor Power, Tmin = 900 K, PHEFigure 20-20. Core Flow, = 900 K, PHE1]

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2 toGNRO-2014/00088Non-Proprietary InformationPage 19 of 28Figure 20-21. Dome Pressure, Tmin = 900 K, PHEFigure 20-22. Maximum Peak Clad Temperature, Tnn = 900 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 20 of 28Figure 20-23. Downcomer Level, Tmin = 900 K, PHE[[Figure 20-24. Feedwater Flow, Train = 900 K, PHE

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2 toGNRO-2014/00088Non-Proprietary InformationPage 21 of 28Figure 20-25. Steamline Flow, Tmin = 900 K, PHEFigure 20-26. Feedwater Temperature, T.. = 900 K, PHE

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2 toG N RO-2014/00088Non-Proprietary InformationPage 22 of 28Figure 20-27. Core Inlet Subcooling, Trin = 900 K, PHE

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2 toG N RO-2014/00088Non-Proprietary InformationPage 23 of 28ATWSI-TTWBP PLOTSTrin = 900 K, BOC

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2 toGNRO-2014/00088Non-Proprietary InformationPage 24 of 28Figure 20-28. Reactor Power, Tmin = 900 K, BOCFigure 20-29. Core Flow, Tn.. = 900 K, BOC

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2 toGNRO-2014/00088Non-Proprietary InformationPage 25 of 28Figure 20-30. Dome Pressure, Tn. = 900 K, BOC[[I1]Figure 20-31. Maximum Peak Clad Temperature, Tna. = 900 K, BOC

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2 toGNRO-2014/00088Non-Proprietary InformationPage 26 of 28Figure 20-32. Downcomer Level, Trai = 900 K, BOCFigure 20-33. Feedwater Flow, Trn = 900 K, BOC

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2 toG N RO-2014/00088Non-Proprietary InformationPage 27 of 28Figure 20-34. Steamline Flow, Tmin = 900 K, BOCFigure 20-35. Feedwater Temperature, T",i = 900 K, BOC

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2 toGNRO-2014/00088Non-Proprietary InformationPage 28 of 28Figure 20-36. Core Inlet Subcooling, Tni = 900 K, BOC[I

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3 toGNRO-2014/00088GEH Affidavit for Attachment 1 GE-Hitachi Nuclear Energy Americas LLCAFFIDAVITI, James F. Harrison, state as follows:(1) I am the Vice President, Regulatory Affairs, Fuel Licensing, of GE-Hitachi Nuclear EnergyAmericas LLC ("GEH"), and have been delegated the function of reviewing the informationdescribed in paragraph (2) which is sought to be withheld, and have been authorized toapply for its withholding.(2) The information sought to be withheld is contained in Enclosures 1 and 3 of GEH letter,GEH-GGNS-AEP-647, "GEH Response to MELLLA+ NRC RAI 20," dated October 30,2014. The GEH proprietary information in Enclosure 1, which is entitled "GEH Responseto NRC RAI 20 in Support of GGNS MELLLA+ LAR," is identified by a dotted underlineinside double square brackets. .Tlis sentence is.an example..* The content ofEnclosure 3 is proprietary in its entirety. The labelling of the Enclosure 3 content carriesthe notation "GEH Proprietary Information -Class II (Internal)13 .' In each case, thesuperscript notation 13 refers to Paragraph (3) of this affidavit, which provides the basis forthe proprietary determination.(3) In making this application for withholding of proprietary information of which it is theowner or licensee, GEH relies upon the exemption from disclosure set forth in the Freedomof Information Act ("FOIA"), 5 U.S.C. Sec. 552(b)(4), and the Trade Secrets Act, 18 U.S.C.Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.390(a)(4) for trade secrets(Exemption 4). The material for which exemption 'from disclosure is here sought alsoqualifies under the narrower definition of trade secret, within the meanings assigned tothose terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass EnergyProject v. Nuclear Regulatory Commission, 975 F.2d 871 (D.C. Cir. 1992), and PublicCitizen Health Research Group v. FDA, 704 F.2d 1280 (D.C. Cir. 1983).(4) The information sought to be withheld is considered to be proprietary for the reasons setforth in paragraphs (4)a. and (4)b. Some examples of categories of information that fit intothe definition of proprietary information are:a. Information that discloses a process, method, or apparatus, including supporting dataand analyses, where prevention of its use by GEH's competitors without license fromGEH constitutes a competitive economic advantage over other companies;b. Information that, if used by a competitor, would reduce their expenditure of resourcesor improve their competitive position in the design, manufacture, shipment,installation, assurance of quality, or licensing of a similar product;c. Information that reveals aspects of past, present, or future GEH customer-fundeddevelopment plans and programs, resulting in potential products to GEH;d. Information that discloses trade secret or potentially patentable subject matter forwhich it may be desirable to obtain patent protection.GEH-GGNS-AEP-647Page I of 3 GE-Hitachi Nuclear Energy Americas LLC(5) To address 10 CFR 2.390(b)(4), the information sought to be withheld is being submitted toNRC in confidence. The information is of a sort customarily held in confidence by GEH,and is in fact so held. The information sought to be withheld has, to the best of myknowledge and belief, consistently been held in confidence by GEH, not been disclosedpublicly, and not been made available in public sources. All disclosures to third parties,including any required transmittals to the NRC, have been made, or must be made, pursuantto regulatory provisions or proprietary or confidentiality agreements that provide formaintaining the information in confidence. The initial designation of this information asproprietary information, and the subsequent steps taken to prevent its unauthorizeddisclosure, are as set forth in the following paragraphs (6) and (7).(6) Initial approval of proprietary treatment of a document is made by the manager of theoriginating component, who is the person most likely to be acquainted with the value andsensitivity of the information in relation to industry knowledge, or who is the person mostlikely to be subject to the terms under which it was licensed to GEH.(7) The procedure for approval of external release of such a document typically requires reviewby the staff manager, project manager, principal scientist, or other equivalent authority fortechnical content, competitive effect, and determination of the accuracy of the proprietarydesignation. Disclosures outside GEH are limited to regulatory bodies, customers, andpotential customers, and their agents, suppliers, and licensees, and others with a legitimateneed for the information, and then only in accordance with appropriate regulatoryprovisions or proprietary or confidentiality agreements.(8) The information identified in paragraph (2), above, is classified as proprietary because itcontains the details of GEH methodology. These methods, techniques, and data along withtheir application to the design, modification, and analyses were achieved at a significantcost to GEH.The development of the evaluation processes along with the interpretation and applicationof the analytical results is derived from the extensive experience databases that constitute amajor GEH asset.(9) Public disclosure of the information sought to be withheld is likely to cause substantialharm to GEH's competitive position and foreclose or reduce the availability of profit-making opportunities. The information is part of GEH's comprehensive BWR safety andtechnology base, and its commercial value extends beyond the original development cost.The value of the technology base goes beyond the extensive physical database andanalytical methodology and includes development of the expertise to determine and applythe appropriate evaluation process. In addition, the technology base includes the valuederived from providing analyses done with NRC-approved methods.The research, development, engineering, analytical and NRC review costs comprise asubstantial investment of time and money by GEH. The precise value of the expertise todevise an evaluation process and apply the correct analytical methodology is difficult toquantify, but it clearly is substantial. GEH's competitive advantage will be lost if itsGEH-GGNS-AEP-647Page 2 of 3 GE-Hitachi Nuclear Energy Americas LLCcompetitors are able to use the results of the GEH experience to normalize or verify theirown process or if they are able to claim an equivalent understanding by demonstrating thatthey can arrive at the same or similar conclusions.The value of this information to GEH would be lost if the information were disclosed to thepublic. Making such information available to competitors without their having beenrequired to undertake a similar expenditure of resources would unfairly provide competitorswith a windfall, and deprive GEH of the opportunity to exercise its competitive advantageto seek an adequate return on its large investment in developing and obtaining these veryvaluable analytical tools.I declare under penalty of perjury that the foregoing is true and correct.Executed on this 30th day of October 2014.rJames F. HarrisonVice President, Fuel Licensing, Regulatory AffairsGE-Hitachi Nuclear Energy Americas LLC3901 Castle Hayne Rd.Wilmington, NC 28401James.Harrison@ge.comGEH-GGNS-AEP-647Page 3 of 3 }}