ML072770498

2007/01/18-Oyster Creek September 2007 Evidentiary Hearing - Applicant Exhibit 21, Amergen'S Oyster Creek Generating Station License Renewal ACRS Presentation, Slides 75-76, Showing Statistical Methodology Used to Evaluate External UT Grid

ML072770498
Person / Time
Site:	Oyster Creek
Issue date:	01/18/2007
From:	AmerGen Energy Co
To:	Office of Nuclear Reactor Regulation, NRC/SECY
SECY RAS
References
50-219-LR, ACRS-3378, AmerGen-Applicant-21, NRC-1398, RAS 14228
Download: ML072770498 (3)

Text

.1.APPLICANT'S EXH. 21 Official Transcript of Proceedingsj q_/.&. 7?NUCLEAR REGULATORY COMMISSION i DOCKETED USNRC October 1, 2007 (10:45pm).1 OFFICE OF SECRETARY RULEMAKINGS AND ADJUDICATIONS STAFF Reactor Safeguards License Renewal Title: Advisory Committee on Subcommittee on Plant I Docket Number: Location: Date:..(not applicable)

Rockville, Maryland, Thursday, January 18, PROCESS USING ADAMS TEMPLATE:

ACRSIACNW-O05 SUNSI REVIEW COMPLETE U.S. NUCLEAR REGULATORY COMMISSION In the Matter of Ahy A\ZIRG CID' L-I." Docket No.tI'-01 IL- Official Exhibit No. *2 O"-ED b ~r: cant ensce intervenor NR.jStajf Other IDENTIFIED on I /- 64Witness/Panel

/Action Taken: AD ITTED EJECTED WITHDRAWN Reporter/Clerk_________________

Work Order No.: NRC-1 398 Pages 1-371 NEAL R. GROSS AND CO., INC.Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.Washington, D.C. 20005 (202) 234-4433

._' Tle/n P [&ý'e = 5 EC Y_SEc y- 0 P Oyster Creek Generating Station License Renewal ACRS Presentation

-January 18, 2007 ACRS Presentation AmerGenCm... An Exelon Company Statistical Methodology 49 UT readings are recorded over a 6" by 6" area.AmierGen.1" (Typ.)Oiameter of each hote between 9/16' anti 5W8.I/16' by 114" slt centered (Typ.)000,o 0 vQ 0 0 Q4-~00 4 M.-0. 0" 0*0~ AI'~00OQi~~A stainless steel template is used to ensure that the readings are recorded consistently and in same location (+4- 1116") every time.For each location, the mean and standard error and the thinnest of the 49 readings are calculated after each inspection.

6" (Typ.)1" (Typ.)75 AmerGen.Statistical Methodology Because of roughness of the exterior surface of the drywell shell in the sand bed, there is uncertainty in the mean thickness calculated for each. grid location e The major contributor to .the uncertainty in the means is the variance from point to point due to the rough surface and not inaccuracy or repeatability of the UT Instrumentation 76 38