ML14132A195

ANP-3304NP, Rev. 0, Areva Response to NRC Follow-Up on Srxb RAI-6: ASME Overpressure Analysis.

ML14132A195
Person / Time
Site:	Monticello
Issue date:	05/09/2014
From:	AREVA NP
To:	Office of Nuclear Reactor Regulation
References
L-MT-14-041, TAC MF2479 ANP-3304NP, Rev. 0
Download: ML14132A195 (14)

Text

L-MT-14-041Enclosure 1ENCLOSURE 1AREVA LICENSING REPORT NO. ANP-3304NP, REVISION 0AREVA Response to NRC Follow-Up onSRXB RAI-6: ASME Overpressure AnalysisNon-Proprietary9 pages follow Controlled DocumentAAREVAAREVA Response to NRC Follow-Up on ANP-3304NPRevision 0SRXB RAI-6: ASME OverpressureAnalysisLicensing ReportApril 2014AREVA Inc.(c) 2014 AREVA Inc.

Controlled DocumentCopyright © 2014AREVA Inc.All Rights Reserved Controlled DocumentAREVA Inc.ANP-3304NPRevision 0AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensing Report Page iNature of ChangesSection(s)Item or Page(s) Description and Justification1 All Initial Issue Controlled DocumentAREVA Inc.AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensina RpnnrtANP-3304NPRevision 0Paae iiContents1.02.03.0PaqeINTRODUCTION ............................................................................................... 1-1AREVA RESPONSE ......................................................................................... 2-1REFERENCES .................................................................................................. 3-1List of TablesTable 1 Monticello Sensitivity Results for Initial Dome Pressure ................................ 2-1 Controlled DocumentAREVA Inc.AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensinq ReportANP-3304NPRevision 0Pa~qe iiiNomenclatureAcronymASMENRCRAISRXBDefinitionAmerican Society of Mechanical EngineersNuclear Regulatory Commission, U.S.Request for Additional InformationReactor Systems Branch of NRC Controlled DocumentAREVA Inc. ANP-3304NPRevision 0AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensing Report Page 1-11.0 INTRODUCTIONThe ASME overpressure analysis is performed to demonstrate the safety/relief valveshave sufficient capacity and performance to satisfy the requirements established by theASME Boiler and Pressure Vessel Code. For Monticello the maximum allowablereactor dome pressure is 1332 psig (1347 psia) and the maximum allowable vesselpressure is 1375 psig (1390 psia). In SRXB RAI-6 the NRC staff requested justificationthat it is conservative to initiate this analysis from the maximum initial dome pressure.This was requested since if the event was initiated from a lower pressure condition atthe same power level, the initial steady state void fraction could be higher, leading to agreater void collapse and resultant neutron flux spike. In Enclosure 2 of Reference 1,the licensee provided a response to SRXB RAI-6.In Reference 2 the NRC provided a follow-up RAI.Follow-Up to SRXB RAI-6 re: ASME Overpressure AnalysisThe NRC staff requested the licensee to justify the assumption for the maximumallowable initial dome pressure. At a lower pressure condition at the same power level,the initial steady state void fraction could be higher, leading to a greater void collapseand resultant neutron flux spike.In its letter dated January 31, 2014, the licensee provided a response to SRXB RAI-6,acknowledging the potentially limiting characteristics of a lower initial dome pressure,and confirmed that the higher pressure initial condition was more limiting. The licenseestated:... a lower initial dome pressure may experience a larger pressure increase (peakpressure -initial pressure) during the event. However, a lower initial domepressure also has more margin to the pressure limit. AREVA calculations haveshown the increase in the pressure rise during the event does not offset theincrease in initial pressure margin.The licensee also provided results of an analysis, applicable to Monticello, thatevaluated both initial pressure conditions, and indicated that the lower initial pressureresult was bounded by the higher initial pressure result by a margin of 5 pound per Controlled DocumentAREVA Inc. ANP-3304NPRevision 0AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensingq Report Paqe 1-2square inch (psi). The NRC staff verified the licensee's response, which is based onAREVA's prior modeling experience, by reviewing the topical report suite describingthese modeling approaches. The NRC staff was unable to locate, in its record system,a clear disposition for this initial condition that verified the licensee's assertion that thisanalysis would be applicable to Monticello. In light of the facts that the difference inpeak pressures in the sensitivity analyses was 5 psi, and the licensee's indicatedmargin to the dome pressure safety limit was 6 psi, the NRC staff determined thatsupplemental information is required to verify the applicability of the experientialanalyses to Monticello specifically.Please provide relevant excerpts from an NRC-approved topical report with adisposition for the selection of initial conditions, or demonstrate that the chosen initialcondition is the most conservative with respect to the limiting vessel pressure.

Controlled DocumentAREVA Inc. ANP-3304NPRevision 0AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensingq Report Page 2-12.0 AREVA RESPONSEAREVA topical reports do not address the selection of the initial dome pressure that isconservative for calculating the peak pressure for ASME overpressure analysis.Therefore, Monticello specific calculations have been performed to demonstrate that themaximum initial dome pressure is the most conservative initial pressure for calculatingthe Monticello peak transient pressure with AREVA transient methods.Monticello ASME analyses are summarized in Section 7.1 of Reference 4. The limitingconditions were repeated with lower values for the initial dome pressure. For each initialdome pressure, an energy balance for the vessel was performed to determine theappropriate values for the steam flow, core inlet enthalpy etc.The Monticello calculations are summarized in Table 1. These results show the trenddescribed in Reference 1. For the reasons mentioned in the original RAI, a lower initialdome pressure experiences a larger pressure increase (peak pressure -initialpressure) during the event. However, a lower initial dome pressure also has moremargin to the pressure limit. The AREVA calculations for Monticello show the sametrend described in the original response; when the ASME analysis is performed with alower initial dome pressure, the increase in the pressure rise during the event does notoffset the increase in initial pressure margin.Table 1 Monticello Sensitivity Results for Initial Dome PressureInitial Dome Peak Vessel Pressure Peak Dome PressurePressure [psia] Lower Plenum [ psig] [psig][1040 1360 1326Pressure Limit 1375 1332 Controlled DocumentAREVA Inc. ANP-3304NPRevision 0AREVA Response to NRC Follow-Up on SRXB RAI-6: ASME Overpressure AnalysisLicensingq Report Page 3-13.0 REFERENCES1. Letter from Xcel Energy to NRC, "AREVA ATRIUM 1 OXM Fuel Transition -Response to Request for Additional Information (TAC MF2479)", L-MT-14-003,January 31, 2014 (ML 14035A297).2. Email from NRC (Terry Beltz) to Xcel Energy (John Fields), "Monticello NuclearGenerating Plant -NRC Staff Request for Additional Information (Follow-upQuestion) re:AREVA Fuel Transition License Amendment Request (TAC No.MF2479)", March 27, 2014.3. Letter from Xcel Energy to NRC, "License Amendment Request for Transition toAREVA ATRIUM 1OXM Fuel and AREVA Safety Analysis Methodology",L-MT-13-055, July 15, 2013 (ML 13200A187).4. ANP-3213(P) Revision 1, Monticello Fuel Transition Cycle 28 Reload LicensingAnalysis (EPU/MELLLA), AREVA NP, June 2013.

L-MT-14-041Enclosure 3ENCLOSURE 3AREVA AFFIDAVIT FORWITHHOLDING PROPRIETARY INFORMATION3 pages follow AFFIDAVITSTATE OF WASHINGTON )) ss.COUNTY OF BENTON )1. My name is Alan B. Meginnis. I am Manager, Product Licensing, for AREVAInc. and as such I am authorized to execute this Affidavit.2. I am familiar with the criteria applied by AREVA to determine whether certainAREVA information is proprietary. I am familiar with the policies established byAREVA to ensure the proper application of these criteria.3. I am familiar with the AREVA information contained in the reportANP-3304P, Revision 0, "AREVA Response to NRC Follow-Up on SRXB RAI-6: ASMEOverpressure Analysis," dated April 2014 and referred to herein as "Document." Informationcontained in this Document has been classified by AREVA as proprietary in accordance with thepolicies established by AREVA for the control and protection of proprietary and confidentialinformation.4. This Document contains information of a proprietary and confidential natureand is of the type customarily held in confidence by AREVA and not made available to thepublic. Based on my experience, I am aware that other companies regard information of thekind contained in this Document as proprietary and confidential.5. This Document has been made available to the U.S. Nuclear RegulatoryCommission in confidence with the request that the information contained in this Document bewithheld from public disclosure. The request for withholding of proprietary information is madein accordance with 10 CFR 2.390. The information for which withholding from disclosure is requested qualifies under 10 CFR 2.390(a)(4) "Trade secrets and commercial or financialinformation."6. The following criteria are customarily applied by AREVA to determine whetherinformation should be classified as proprietary:(a) The information reveals details of AREVA's research and development plansand programs or their results.(b) Use of the information by a competitor would permit the competitor tosignificantly reduce its expenditures, in time or resources, to design, produce,or market a similar product or service.(c) The information includes test data or analytical techniques concerning aprocess, methodology, or component, the application of which results in acompetitive advantage for AREVA.(d) The information reveals certain distinguishing aspects of a process,methodology, or component, the exclusive use of which provides acompetitive advantage for AREVA in product optimization or marketability.(e) The information is vital to a competitive advantage held by AREVA, would behelpful to competitors to AREVA, and would likely cause substantial harm tothe competitive position of AREVA.The information in the Document is considered proprietary for the reasons set forth inparagraphs 6(b), 6(d) and 6(e) above.7. In accordance with AREVA's policies governing the protection and control ofinformation, proprietary information contained in this Document have been made available, on alimited basis, to others outside AREVA only as required and under suitable agreement providingfor nondisclosure and limited use of the information.8. AREVA policy requires that proprietary information be kept in a secured file orarea and distributed on a need-to-know basis.

9. The foregoing statements are true and correct to the best of my knowledge,information, and belief.Ii-SUBSCRIBED before me this ._______day of A -v V- ,2014.NOTARY PUBLIC, STATE OF WA/ GTONMY COMMISSION EXPIRES: 1/14/2016