ML14149A435

South Texas Project, Units 1 and 2 - ALION-REP-STP-8998-02, Rev. 0, STP Casa Grande Analysis and LAR Enclosure 4-3 RAI Response, Enclosure 1 to Attachment 1

ML14149A435
Person / Time
Site:	South Texas
Issue date:	02/14/2014
From:	Munoz D ALION Science & Technology Corp
To:	Office of Nuclear Reactor Regulation
Shared Package
ML14149A439	List: ML14149A434 ML14149A435 NOC-AE-14003103, University of Texas White Paper, Means of Aggregation and NUREG-1829: Geometric and Arithmetic Means, Rev. 3, Enclosure 2 to Attachment 1
References
GSI-191, NOC-AE-14003103, ST133840343, TAC MF2400, TAC MF2401 ALION-REP-STP-8998-02, Rev. 0
Download: ML14149A435 (6)

Text

NOC-AE-1 4003103Attachment 1Enclosure 1Enclosure 1 to Attachment 1Alion report supporting resolution of APLAB, CASA Grande -LOCA Frequencies: RAI 4(ALION-REP-STP-8998-02, Rev. 0, "STP CASA Grande Analysis and LAR Enclosure 4-3RAI Response")

NOC-AE-1 4003103Attachment 1Enclosure 1Page 1 of 5SCLIONSCIENCE AND TECHNOLOGYTECHNICAL DOCUMENT COVER PAGEDocument No: ALION-REP-STP-8998-02 Revision:0 Page 1 of 5Document Title: STP CASA Grande Analysis and LAR Enclosure 4-3 RAI 1ResponseProject No: STP-8898Project Name: STP Risk Informed GSI-191 SupportClient: STP Nuclear Operating CompanyDocument Purpose/Summary: Request for additional information 1 (RAI 1) inquired about reference specific, pertinentweld break frequency information that was used in the STP CASA Grande analysis documentation (LAR Enclosure 4-3).This document cross references LAR Enclosure 4-3 with references of interest and their contents, and provides high-level clarification of their usage.This document is not considered safety related. However, it has been prepared, reviewed, and approved.Design Verification Method:X Design ReviewAlternative Calculation___ Qualification TestingProfessional Engineer (if required) Approval: N/A Date N/ADominic Muhioz/ Ernie Kee* 2/14/2014Prepared By:Printed/Typed Name Signature DateBruce Letellier 2/14/2014Reviewed By:Printed/Typed Name Signature DateMegan Stachowiak 2/14/2014Approved By:Printed/Typed Name Signature Date NOC-AE-1 4003103Attachment 1Enclosure 1Page 2 of 5ALION-REP-STP-8998-02 Revision: 0STP CASA Grande Analvsis and LAR 4-3 RAI I Document Number:Document Title:STP CASA Grande Analvsis and LAR Enclosure 4-3 RAI I ResrionseREVISION DATE Description0 See Cover Initial release.Page*Denotes a preparer from outside of the ALION organization. All technical information provided and its correctness are solely theresponsibilities of internal staff.

NOC-AE-1 4003103Attachment 1Enclosure 1Page 3 of 5Table of ContentsTable of Contents ....................................................................................................................... 3RA I #1 PRA Licensing Branch (A PLA) ............................................................................. 4R e sp o n se ....................................................................................................................................... 4Availability of Reference 8 for Review ........................................................................... 4Confirm ation of References ............................................................................................. 4Specific Aspects of References used in the LA R ......................................................... 5Cross Reference Sum m ary ........................................................................................... 5Clarification Details ...................................................................................................... 5 NOC-AE-1 4003103Attachment 1Enclosure 1Page 4 of 5RAI #1 PRA Licensing Branch (APLA)Volume 3 of the license amendment request (LAR) describes the process used to assign break frequenciesto welds in containment and cites two documents listed as references 7 & 8:7. KNF Consulting Services LLC and Scandpower Risk Management Inc. Development of LOCAInitiating Event Frequencies for South Texas Project GSI-191 Final Reportfor 2011 Work Scope.September 2011.8. University of Texas at Austin. Modeling and Sampling LOCA Frequency and Break Size for STPGSI-191 Resolution. September 2012.The staff notes that several versions of these documents are publically available in the NRC's Agency-wide Documents Access and Management System (ADAMS). A brief comparison of the fitted Johnsonparameters in the above version of Reference 8 to Table 2.2.2 revealed differences between the LAR andthe referenced document. Please confirm that Volume 3 contains the correct information from thesereports and cites the correct versions of the aforementioned references. Please clarify exactly whichaspects of the aforementioned references (e.g., by providing specific section or equation numbers) areused in the STP pilot application.ResponseAvailability of Reference 8 for ReviewLAR Enclosure 4-3 Reference 8 has been sent for publication in the NRC PDR with STP transmittal letterNOC-AE-13003070 (Letter, dated December 23, 2013, M.D. Meier to the NRC Document Control Desk) inorder to make it publically available for review.Confirmation of ReferencesThe two referenced documents number (7), and (8) in STP's GSI-191 submittal are shown below as listedin LAR Enclosure 4-3.7. KNF Consulting Services LLC and Scandpower Risk Management Inc. Development ofLOCA Initiating Event Frequencies for South Texas Project GSI-191 Final Report for 2011Work Scope. September 2011.8. University of Texas at Austin. Modeling and Sampling LOCA Frequency and Break Size forSTP GSI-191 Resolution. September 2012.The revision number and date of LAR Enclosure 4-3 Reference 7 as written has been confirmed to becorrect.The revision number and date of LAR Enclosure 4-3 Reference 8 as written has been confirmed to becorrect.

NOC-AE-1 4003103.Attachment 1Enclosure 1Page 5 of 5Specific Aspects of References used in the LARCross Reference SummaryTable 1: LAR End 4-3 Cross Reference MatrixCross ReferenceEnclosure 4-3 (Table)CrsRerncLAR Encl. 4-3 Ref. No. Ref. Section Ref. Page Ref. Table(37) 7.8 7-55 7.19Table 2.2.2 (8) 5 44 31(8) 2.1 7(8) 5 44 32Tables 2.2.3-2.2.10 (7) 5 , 5-1 to5-4 "2Clarification DetailsWeld break frequencies are estimated in NUREG 1829 (Ref. 37 of LAR Encl. 4-3). The values from thiselicitation are titled "NUREG-1829 Quantiles" in Table 2.2.2 of LAR Encl. 4-3, and are identical to thevalues given in Table 7.19 (Pg. 7-55) of NUREG-1829 for current-day break frequencies with theexception of two additional break sizes. These two additional break sizes (in LAR Encl. 4-3, Table 2.2.2)were linearly interpolated between NUREG-1829 frequencies to be consistent with the STP probabilisticrisk assessment (PRA) SBLOCA and MBLOCA bounding break sizes of 2 inches (SBLOCA-MBLOCA) and 6inches (MBLOCA-LBLOCA). Interpolation was performed for the 5th percentile, median, mean, and 95thquantiles of the NUREG-1829 distributions as described in Section 5 of Encl. 4-3 Reference 8, and theinterpolated values are shown in Encl. 4-3 Reference 8, Table 31.The quantiles of current-day break frequencies in NUREG-1829 Table 7.19 were fit to a parametric(Bounded Johnson) distribution as described in Section 2 of LAR Encl. 4-3 Reference 8. The Johnsonparameters from Table 2.2.2 of LAR Encl. 4-3 are also described in LAR Encl. 4-3 Reference 8. Asdescribed, the parameters of the Johnson distributions closely fit the 5th percentile, median, and 95thpercentile of the NUREG-1829 distribution values (Section 2.1, Table 3 of LAR Encl. 4-3 Reference 8) withexplicitly listed parameter values in LAR Encl. 4-3 Reference 8 Table 2. The parametric fit for a Johnsondistribution at the two additional break sizes at the interpolated values of 2 and 6 inches (describedabove) are given in LAR Encl. 4-3 Reference 8 Table 32. Estimates of the mean break frequency reportedin NUREG-1829 Table 7.19 were not used in this analysis.Reference 7 Tables 5-1 through 5-4 are the source for the values in LAR Encl. 4-3 Tables 2.2.3-2.2.10. Thevalues from tables 5-1 through 5-4 were used as weighting factors to distribute NUREG-1829 total breakfrequencies across weld types and to containment locations by matching weld types with containmentweld data. In LAR Encl. 4-3, conservation of NUREG-1829 total break frequency is referred to as the"top-down" portion of the "hybrid" break frequency approach. Tables 5-1 through 5-4 from reference 7represent the product of "bottom-up" aggregation of cross-industry data on observed flaws ordegradation that may lead to breaks.