ML13217A373

Monticello - Maximum Extended Load Line Limit Analysis Plus License Amendment Request - Request for Additional Information Responses

ML13217A373
Person / Time
Site:	Monticello
Issue date:	07/31/2013
From:	Schimmel M A Northern States Power Co, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-13-070, TAC ME3145
Download: ML13217A373 (17)

Text

{{#Wiki_filter:ENCLOSURE 1 CONTAINS PROPRIETARY INFORMATIONWITHHOLD FROM PUBLIC DISCLOSURE IN ACCORDANCE WITH 10 CFR 2.390@ XcelEnergyMonticello Nuclear Generating Plant2807 W County Rd 75Monticello, MN 55362July 31, 2013L-MT-13-07010 CFR 50.90U.S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555-0001Monticello Nuclear Generating PlantDocket 50-263Renewed License No. DPR-22Subject: Maximum Extended Load Line Limit Analysis Plus License AmendmentRequest -Request for Additional Information Responses (TAC ME3145)References:1)Letter from T J O'Connor (NSPM), to Document Control Desk (NRC),"License Amendment Request: Maximum Extended Load Line LimitAnalysis Plus," L-MT-10-003, dated January 21, 2010. (ADAMSAccession No. ML100280558)2) Email from T Beltz (NRC) to J Fields (NSPM), "Monticello -MELLLA+ Review -Draft Requests for Additional Information (TACNo. ME3145).docx," dated April 9, 2013.In Reference 1, Northern States Power Company, a Minnesota corporation (NSPM),doing business as Xcel Energy, requested approval of an amendment to the MonticelloNuclear Generating Plant (MNGP) Renewed Operating License (OL) and TechnicalSpecifications (TS). The proposed change would allow operation in the expandedMaximum Extended Load Line Limit Analysis Plus (MELLLA+) domain.In Reference 2 the NRC provided a Request for Additional Information (RAI) pertainingto the quench front velocity in the TRACG model.Enclosure 1 provides a report from General Electric -Hitachi (GEH) letter, GE-MNGP-AEP-3296R2, "GEH Response to RAI-3 Parts a-g and i." Enclosure 1 containsproprietary information. Document Control DeskPage 2Enclosure 2 provides a non-proprietary copy of the Enclosure 1 RAI responses. Thenon-proprietary copy of the RAI responses is being provided based on the NRC'sexpectation that the submitter of the proprietary information should provide, if possible,a non-proprietary version of the document with brackets showing where the proprietaryinformation has been deleted.Enclosure 3 contains an affidavit executed to support withholding Enclosure 1 frompublic disclosure. Information in Enclosure 1 contains proprietary information asdefined by 10 CFR 2.390. The affidavit sets forth the basis on which the informationmay be withheld from public disclosure by the NRC and addresses with specificity theconsiderations listed in 10 CFR 2.390(b)(4). Accordingly, NSPM respectfully requeststhat the proprietary information in Enclosure 1 be withheld from public disclosure inaccordance with 10 CFR 2.390(a)4, as authorized by 10 CFR 9.17(a)4.Correspondence with respect to the copyright or proprietary aspects of GEH informationor the supporting GEH affidavit in Enclosure 3 should be addressed to James FHarrison, Vice President, Regulatory Affairs, GE-Hitachi Nuclear Energy Americas LLC,3901 Castle Hayne Road, Wilmington, NC 28401.The supplemental information provided herein does not change the conclusions of theNo Significant Hazards Consideration and the Environmental Consideration evaluationsprovided in Reference 1 for the MELLLA+ license amendment request.In accordance with 10 CFR 50.91(b), a copy of this application supplement, withoutenclosures is being provided to the designated Minnesota Official.Summary of CommitmentsThis letter makes no new commitments or revisions to existing commitments. Document Control DeskPage 3I declare under penalty of perjury that the foregoing is true and correct.Executed on: July ;9, 2013Mark A. SchimmelSite Vice-PresidentMonticello Nuclear Generating PlantNorthern States Power Company-MinnesotaEnclosures (3)cc: Regional Administrator, Region Ill, USNRC (w/o enclosures)Project Manager, Monticello Nuclear Generating Plant, USNRCResident Inspector, Monticello Nuclear Generating Plant, USNRC (w/oenclosures)Minnesota Department of Commerce (w/o enclosures) L-MT-1 3-070ENCLOSURE 2GE-MNGP-AEP-3296R2, ENCLOSURE 2GEH RESPONSE TO RAI-3 PARTS A-G AND INON-PROPRIETARY9 pages follow ENCLOSURE 2GE-MNGP-AEP-3296R2GEH Response to RAI-3 Parts a-g and iNon-proprietary Information -Class I (Public)NON-PROPRIETARY NOTICEThis is a non-proprietary version of the Enclosure 1 of GE-MNGP-AEP-3296R2 whichhas the proprietary information removed. Portions of the document that have beenremoved are indicated by an open and closed bracket as shown here [[ I]. GE-MNGP-AEP-3296R2 Non-proprietary Information- Class I (Public)Enclosure 2Page 2 of 9RAI-3Detailed Code Questionsa. Please explain how TRACG differentiates between the quench front and the bulk liquidphase in any given node during A TIWS-I conditions when heat is transferred from a hotrod to the liquid downstream of the quench front.ResponseTRACG employs a one-dimensional two-fluid model in each fuel channel. Thereforethere is one void fraction and one liquid temperature for each node. Heat transfer to thebulk liquid does vary between individual surfaces in the node, such as the surfaces forindividual fuel rods, water rods and channel box. Heat transfer to the bulk liquid iscalculated according to the heat transfer selection logic described in Section 6.6.2 of theTRACG Model Description LTR [3-1]. The sum of the heat transfer to the liquid from allthe surfaces in the node is the net heat transfer to the bulk liquid. If a surface in a nodecontains a quench front, the quench front heat transfer is calculated as described inSection 6.6.13 of the TRACG Model LTR [3-1] and discussed in the response to RAI 2 inReference 3-2. The quench front heat transfer is applied to the conduction solution forthe surface containing the quench front, where it becomes an energy loss, and added as asource term to the net heat transfer to the bulk liquid in the node.b. In the response to RAI 2, the first term of Equation 2-2 describes heat transfer accordingtofihn boiling.Please explain how Equation 2-2 accounts for only part of a node being in filn boiling.Response[[ GE-MNGP-AEP-3296R2Enclosure 2Page 3 of 9Non-proprietary Information- Class I (Public)c. The response to RAI 2 states that "For conditions where the energy generation in the fuelis high, the net heat removal given by the difference between Equation 2-2 and the energygeneration rate is reduced and the quenching is similarly slowed down."Please describe by what mechanism is the quench front "slowed downi" in TRA CG?ResponseRAI 2 of Reference 3-2 contains the statement: [[ GE-MNGP-AEP-3296R2Enclosure 2Page 4 of 9Non-proprietary Information- Class I (Public)d. In the response to RAI 2, there is a discussion of Equation 2-3 that notes it is used for"conditions where the energy generation in the fiuel rod is small."Please explain how this expression changes if the energy generation is large, as may bethe case during A TWS conditions.ResponsePlease see the response to RAI 3c above for conditions where the energy generation islarge. GE-MNGP-AEP-3296R2 Non-proprietary Information- Class I (Public)Enclosure 2Page 5 of 9e. 1) Equation 2-5 relates the quench front heat transfer coefficient to reflood velocitywhich, according to the response to RAI 2, is derived fiom upstream liquid velocity.However, for non-LOCA scenarios such as A TWS-I, the cladding hot spot may be in alow void inverted annular flin boiling (IAFB) regime with oscillatory flow conditions.Please explain how Equation 2-5 is applied to scenarios such as A TWS-I whereupstream liquid velocity may be reversed.ResponseThe quench front models in TRACG were developed for LOCA application.For top down quenching, it is assumed that the quenching is by a falling film. The heattransfer coefficient used in the quench front model for top down quenching is[[ ]] as described in Section 6.6.13 of Reference 3-1.For bottom reflood quenching the heat transfer coefficient used in the quench front modelis the maximum of the above value and Equation 2-5 from Reference 3-2. Equation 2-5from Reference 3-2 has been retained from TRAC-PIA [3-3] and TRAC-BD1 [3-4] andis based on based on Yu, Farmer and Coney [3-5].For conditions with low void fractions and downward velocities, Equation 2-5 fromReference 3-2 is not applied and the falling film quench front model is conservativelyapplied.2) Additionally, the quench fiont propagation would be well correlated with refloodvelocity for oscillatory flow conditions where low void inverted annular flow candevelop.Please provide the basis for Equation 2-5 as applied to this type of situation.ResponseThe basis for the application of Equation 2-5 from Reference 3-2 is described above andis given in Reference 3-5. GE-MNGP-AEP-3296R2 Non-proprietary Information- Class I (Public)Enclosure 2Page 6 of 93) In the "Monticello Audit slides "presented to the staff during the audit (ADAMSAccession No. ML123400521), the GEH model was compared to oscillatory resultsfrom the Stern Lab tests. However, TRA CG appeared to reduce the clad temperatureand quench much faster than the data in the Stern Lab oscillatoiy dryout tests.Please provide a description about why the reduction in clad temperature and quenchoccur faster in TRACG than in the Stern data occurs.Response GE-MNGP-AEP-3296R2 Non-proprietary Information- Class I (Public)Enclosure 2Page 7 of 9f Equation 6.6-158 in the TRACG Model Description Topical Report is an expression thatprovides the heat transfer coefficient for bottom reflood It is reportedly "based on anempirical correlation developedfor TRAC-P1A based on FLECHT reflood data." TheFLECHT data is referenced as:J.0. Cermak, et al., P WR Full Length Emergency Cooling Heat Transfer(FLECHT) Group I Test Report, WCAP- 7435, Westinghouse ElectricCompany, January 1970.Please provide clarification as to whether this statement is a carryover of thedocumentation for TRA C-P1A?Is the TRACG source code for this equation based on the Yu, Farmer, and Coney data?ResponsePlease see the response to RAI 3.e. Reference 116 in the TRACG Model LTR [3-1] isincorrect; it should be Reference 3-5. This will be corrected in the next revision ofReference 3-1.g. A discussion about Equation 2-5 is included in the response to RAI 2. It is stated that thequench front heat transfer coefficient "is consistent with the observations in Reference 2-9." Reference 2-9 notes that in the evaluation of the Harwell data, the heat transfercoefficient in the vicinity of the advancing quench front was 10O Btu/hr-f!t-F [5.6 x 1IsW/m2-K]. When a reflood velocity of 0.5 in/sec is applied to Equation 2-5, the result is aheat transfer coefficient of]. 6x107 W/m2-KPlease explain the inconsistencies between this result and the observation inReference 2-9.ResponseThere really is no inconsistency. Reference 2-9 (Thompson) of Reference 3-2 is forfalling film rewetting. It shows heat transfer coefficients just behind the quench front onthe order of I05 Btu/ft2-hr-F, which in SI units is 6x105 W/m2-K. TRACG uses a heattransfer coefficient of [[ ]] for the falling film quenching. [[For bottom reflood TRACG uses the model from References 3-4 and 3-5. The model isimplemented as described in the TRAC-BDI Model Description [3-4]: GE-MNGP-AEP-3296R2Enclosure 2Page 8 of 9Non-proprietary Information- Class I (Public)h = FATq = TO -T, is the difference between the Leidenfrost temperature and the liquidtemperature. In the above expression:Fq = aF(F =4.24.1 04V.113-5)3-6)13-7)(1 + VAT)0.130.4839(1 + vATq)20.346for (1 + vAT2) < 40for (1 + vAT2) > 40(3-8)v, is the liquid velocity.In the latter expression for a as described in Reference 3-4 and implemented withinTRACG ATq = T0 -Te is used. An examination of the original paper by Yu, Farmer andConey [3-5] has revealed that u. should be calculated as:=(+ VeAT2) for (1 + veAT2) 40a= , .. (3-9)for (1+ v AT 2) > 40where AT, = Tsat -Te is the amount of liquid subcooling. GE-MNGP-AEP-3296R2 Non-proprietary Information- Class I (Public)Enclosure 2Page 9 of 9i. The response to RAI 2 provides Equation 2-2 to describe total heat removal from the fuel.Please describe the distribution of heat transferred to the two phases in TRA CG.ResponsePlease see the response to RAI 3b.References:3-1 GE Nuclear Energy, "TRACG Model Description," NEDE 32176P, Revision 4, January2008.3-2 Response to Monticello Nuclear Generating Plant -Draft Request for Additionalinformation re: MELLLA+ License Amendment Request Review (TAC No. ME3145) -Revision 1, GE-MNGP-AEP-3223, December 14, 2012.3-3 USNRC, "TRAC-P IA: An Advanced Best-Estimate Computer Program for PWR LOCAAnalysis," NUREG/CR-0665, Los Alamos Scientific Laboratory, May 1979.3-4 USNRC, "TRAC-BDI: An Advanced Best-Estimate Computer Program for BoilingReactor Loss-of-Coolant Accident Analysis," NUREG/CR-2178, October 1981.3-5 S. K. W. Yu, P. R. Farmer and M. W. Coney, "Methods and Correlations for the Predictionof Quenching Rates on Hot Surfaces," International Journal of Multiphase Flow, 3, 1977,pp. 415-443.3-6 Presentations from the NRC Audit of Monticello MELLLA+ ATWS/I, October 240" and25th, GE-MNGP-AEP-321 1, October 30, 2012.3-7 T. S. Thompson, "On the Process of Rewetting a Hot Surface by a Falling Liquid Film,"Nuclear Engineering and Design Volume 31, Issue 2, January 1975, pp 234-245. L-MT-13-070ENCLOSURE 3GENERAL ELECTRIC -HITACHI AFFIDAVIT FORWITHHOLDING PROPRIETARY INFORMATION3 pages follow GE-Hitachi Nuclear Energy Americas LLCAFFIDAVITI, James F. Harrison, state as follows:(1) I am the Vice President Fuel Licensing of GE-Hitachi Nuclear Energy Americas LLC(GEH), and have been delegated the function of reviewing the information described inparagraph (2) which is sought to be withheld, and have been authorized to apply for itswithholding.(2) The information sought to be withheld is contained in Enclosure 1 of GEH letter, GE-MNGP-AEP-3296R2, "GEH Response to MELLLA Plus Requests for AdditionalInformation," dated July 19, 2013. The GEH proprietary information in Enclosure 1, whichis entitled "GEH Response to RAI-3 Parts a-g and i," is identified by a dark red dottedunderline inside double square brackets. This sentence is an .e.x.ample3. In each case,the superscript notation (3) refers to Paragraph (3) of this affidavit that 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 EnergyProiect v. Nuclear Regulatory Commission, 975 F.2.d 871 (D.C. Cir. 1992), and PublicCitizen Health Research Group v. FDA, 704 F.2.d 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 GEH or 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, that may include potential products of GEH.d. Information that discloses trade secret or potentially patentable subject matter forwhich it may be desirable to obtain patent protection.Affidavit for GE-MNGP-AEP-3296R2Page 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 tothe NRC in confidence. The information is of a sort customarily held in confidence byGEH, 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. Access to suchdocuments within GEH is limited to a "need to know" basis.(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 results of an analysis performed by GEH to support the Monticello MaximumExtended Load Line Limit Analysis Plus (MELLLA+) license application. This analysis ispart of the GEH MELLLA+ methodology. Development of the MELLLA+ methodologyand the supporting analysis techniques and information, and their application to the design,modification, and processes were achieved at a significant cost to GEH.The development of the evaluation methodology along with the interpretation andapplication of the analytical results is derived from the extensive experience database thatconstitutes a major 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.Affidavit for GE-MNGP-AEP-3296R2Page 2 of 3 GE-Hitachi Nuclear Energy Americas LLCThe 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 itscompetitors 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 affidavit and the matters stated therein aretrue and correct to the best of my knowledge, information, and belief.Executed on this 19th day of July, 2013.James F. HarrisonVice President Fuel LicensingGE-Hitachi Nuclear Energy Americas LLC3901 Castle Hayne RdWilmington, NC 28401james.harrison@ge.comAffidavit for GE-MNGP-AEP-3296R2Page 3 of 3 }}