ML20138G737

Forwards Response to RAI Re Combustion Engineering Designed Welded SG Tube Sleeves

ML20138G737
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	12/23/1996
From:	Mueller J COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9701020236
Download: ML20138G737 (2)

Text

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g' , Commonwralth 14hv>n Company l

, . Zion Generating Station 101 Shiloh floulcuni te Zion,11. NU)9 275)?

Tei m 7 w 20s4 l

l December 23,1996 j U.S. Nuclear Regislatory Commission l Attn: Document Control Desk l Washington, D.C. 20555

Subject:

Zion Station Units 1 and 2  ;

l Response to Request for Additional Information Operating Licenses DPR-39 and DPR-48 NRC Docket Nos. 50-295 and 50-304 l

Reference:

Letter from C. Y. Shiraki, U. S. Nuclear Regulatory Commission, to i I. Johnson, Commonwealth Edison, dated September 30,1996, Request for l Additional Information.

i i

l l This letter provides Commonwealth Edison's (Comed's) response to an NRC Request for Additional Information regarding Combustion Engineering designed welded steam generator tube sleeves. Responses to the specific items in the request are provided in the attachment to this letter.

Please direct any questions you may have concerning this submittal to this office.

Respectfully,  ;

[ ,1)./)

J. H. Mueller Site Vice President 7jon Station l'

Attachment l

cc: NRC Regional Administrator - Rill i Zion Station Project Manager - NRR I Senior Resident inspector - Zion Station Office of Nuclear Facility Safety - IDNS

[~ h I IDNS Resident Inspector Zion NLA

." Reg. Assurance File

• 1, l 01 'y DCD Licensing I 9701020236 961223

! PDR ADOCK 05000295' P PDR l

A i,mcom company

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t ATTACHMENT j RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION

1. REQUEST: During the Zion Unit 2 SG tube inspections in the current refueling outage, what is Comed's intention regarding inspection of the upper weld in the existing CE designed welded sleeves? Include inspection scope and nondestructive examination methodologies to be used.

RESPONSE: During the current Zion Unit 2 Outage (Z2R14) inspections of the CE sleeve upper welds were performed using the advanced multi-frequency eddy current tester (Zetec Miz-30) and Plus Point Probe, as described in Topical Report CEN-629-P, Revision 00, Sections 4.5.7 and 5.0. The inspections included 100% of both the newly

installed and the existing sleeves.

2. REQUEST: What is Comed's intention regarding disposition of sleeved tubes with weld zone indications? Include past practice and present intentions. If Comed intends to t leave weld zone indications (WZis) in service, provide the basis for the acceptability of this practice including the uncertainty in locating the exact position of volumetric flaws.

RESPONSE: During the current Zion Unit 2 Refueling Outage (Z2R14) all sleeves identified as having weld zone indications were removed from service by plugging, ,

regardless of the location of the indication relative to the weld centerline. In future outages Comed may elect to leave sleeves with eddy current indications in service, if it ,

is determined that the indications are above the weld centerline / pressure boundary. The {

process to determine if a sleeve with an indication can remain in service is outlined in j Figures 5-1 and 5-2 of Topical Report CEN-629-P, Revision 00. The EPRI Appendix H  ;

qualification document for the use of the Plus Point Probe on CE sleeves qualified the l eddy current technique for determining an indication's location with respect to the weld centerline.

3. REQUEST: The staff is currently reviewing a TS amendment dated September 3,1996, that will add certain portions of the new CE Topical Report to the TS. Commonwealth Edison also docketed a letter dated September 18, 1996, that discusses certain technological enhancements it has adopted, within the requirements of the TS, that have not changed the sleeve design or the reliability of the sleeving process, in its letter of September 18,1996 Comed also docketed its intention to submit a TS amendment that will refer to the process enhancements contained in the letter. l Exclusive of these reviews and commitments, is it Comed's intention to adopt the new CE Topical Report in its entirety? If so, how will Comed incorporate this topical report i into its TS for future sleeving operations? l RESPONSE: Comed intends to request a Techhical Specification amendment which will j allow use of the entire CE Topical Report. The amendment request is scheduled to be l submitted by January 15, 1997, so that the entire report may be used during the Zion Unit 1 Refueling Outage (ZlR15), which is currently scheduled to start on April 5, l 1997.