OAGI0001534_00003 United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of: Entergy Nuclear Operations, Inc. (Indian Point Nuclear Generating Units 2 and 3) ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 | 05000286 Exhibit #: Identified: Admitted: Withdrawn: Rejected: Stricken: Other: NYS000377-00-BD01 10/15/2012 10/15/2012 NYS000377 Submitted: June 19, 2012 • 0 . . II> ., r- .... ,,1- 0 .... ? ****il !am Gene[ator Tube Operation a! Experience 00 Steam Generator 'rube Operationai Experience [ Indign Point 2 EVe,llt ! Nude"f Rpactors I NRC Home Palle] ..... = .. ... = .. ... = .... -= -.•. = .-.= ... === = == .= .... = ....... .. _ ..... ..... .. Early; cOID _mercia1 nuclear power plant steam generator tubes were formed from Alloy 600, a cOITosion-resista.!lt pjgh-nickel alloy- 'Early supplies of the Ailoy 600 tubes were provided in a null-anneal condition. Most of the steam generator tubes which have required plugging over the years have been IT'ill-annef'lled Alloy 600 tubes. Infonnation on the operational experience with Alloy 600 tubes can be found in t,l-je follo'.'!ing NRC Infonnation Notices: • IN 98-27 ""("am Generator Tube End Cracking" • L-r...T 97 -88, "Experiences During Rece· n! ·"team Generat or Tnsoections" • IN 97·49. "B&W Once-ThrQugh Steam Generator Tube Inspection Findings" • IN 97-26. "negl'l'rtation if! Small.Radius V·Bend Regions oLSteam Generator Tubes" eo St,6-38, "Results of Steam Generator Tube " .. 94-62_ "Ot Jt!raiional EXDer1enCe on Steaifi. .. Ocnerator Tube Leaks and Tube Ruptures'! • ll'1 90-49. lIStress Corrosion ("r:.c.king in PWR St eam Generator Tubes': steam geTIerator tube man.ufacturers deterrnined that by the.rrn. a11y treating the AJloy 600 material for later tubes, the corrosion resistance of the tubes was improved Industry experience with thermally tieated Alloy 600 stea.'tl generator tubes suggests that these tubes are more resistant to in-service cracrJng than nlil1-anne aled Alloy 600 tubes. A few indications of degradation in thermally treat.ed Alloy 600 tubes have been reported, however, a.T1d one is discussed in IN 97-26, listed above. f-.JO\V, most steam generator tubes for Hew steam generators are being fabricated from thermally treatec Alloy 690, rul alloy \vith a higher a...'1l0unt of cp..rowiurn and red\lCed amount of nickeL Alloy 690 is considert:d to be very resistant to t..'1e types of degrad:ltion experi.enced by the ..A.lloy 600 lllhes. At this time, the NRC staff js noi aware of any primary br secondary side cracking in P-J1ay 690 tubing. Some WoeS have also been plugged due to fretting and denting, degradation mechanisms due to the design of the support plates and antivibration bars and the presence ofloose pa."ts, rather than tIle tubing material. In the 20 years preceding the failure at Indian Point 2 on February 15,2000, there had been seven steam generator tube ruptures in commercial nuclear power plants, all in tubes fabricated from rrJll-annealed Alloy 600. The last tube rupture occurred in 1993 at Palo Verde. j TJnit It is considered a tube rupture rather ihan mereiy tube leakage when tube leakage of reactor coolant exceeds the- ma..lce . up capacity. SeL Table 1 for information about the seven tube ruptures. Ilf01l2000 Alvj