ML20141G612

Forwards Interim Plugging Criteria Return to Power Rept, Per Sixth Refuel Outage SG ISI Rept

ML20141G612
Person / Time
Site:	Braidwood
Issue date:	05/15/1997
From:	Tulon T COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20141G617	List: ML20141G612 ML20141G636
References
NUDOCS 9705220430
Download: ML20141G612 (2)

Text

_,

t Commonwcalth Edimn Company

.o liraidworx! Generating Station Route 01, flux M Dsareville, IL 60407%i9 4 Tel H15-494-280 i May 15,1997 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555

Subject:

Braidwood Station Unit i Sixth Refuel Outage Steam Generator Inservice inspection Report Docket No. STN 50-456

References:

(1) NUREG-1276, Technical Specifications, Braidwood Station, Unit Nos. I and 2 l (2) Letter from John B.1-losmer to U. S. Nuclear Regulatory l Commission, Additional Information Pertaining to Braidwood I Unit i Locked Tube Circumferential Indications, dated April j 30,1997 )

l Specification 4.4.5.5.d of Reference (1) requires that for the implementation of a voltage based repair criteria for Steam Generator tube suppon plate intersections, the staff should l be notified prior to returning the Steam Generators to service should certain conditions l l

arise.

• The estimated leakage based on the actual measured voltage distribution did not exceed the site allowable limit of 26.8 gpm.

• No indications were identified to extend beyond the confines of the tube support plates (TSP).

• No indications attributed to Primary Water Stress Corrosion Cracking (PWSCC) were identified at TSP elevations.

• No cracking of the TSPs was identified.

• All tubes which previously passed a 0.610 inch bobbin coil probe, passed the 0.610 inch probe during the AIR 06 outage.

The conditional burst probability, based on the actual measured voltage distribution, f

did not exceed lx10 2

• One circumferential indication was identified at a dented TSP intersection (24 volts). /

This indication was removed from service. /I

• A Steam Generator internals inspection identified circumferenoal indications at the top of the tubesheet in the tubes locked for the 3.0 Volt interim Plugging Criteria. An assessment of the safety significance of these tubes having circumferential indications and a root cause determination was sent to the NRC in Reference (2).

220083 ,

9705220430 970515 ADOCK 05000456; POR O l lhl A l'nicom Company

s t

Document Conno! Desk May 15.1997 Pane 2 Attached is an Interim Plugging Criteria Return to Power Report. The results from the Braidwood Unit 1 Sixth Refuel Outage (AIR 06) Steam Generator eddy current examination are contained in this report. The examination incorporated the requirements of the 3.0 Volt Interim Plugging Criteria for tube support plate intersections. A Technical Specification amendment for the 3.0 Volt Interim Plugging Criteria was approved by the NRC on May 14,1997.

Specification 4.4.5.5.e of Reference (1) requires that the results ofinspections of F* tubes be reported to the Commission prior to the resumption of plant operation. F* was not applied to any Steam Generator tubes during the Braidwood Unit I sixth refuel outage.

F* has never been applied to any tubes in the Bradwood Unit i Steam Generators.

l Please direct any questions regarding this submittal to Terrence Simpkin, Braidwood

! Regulatory Assurance Supervisor, (815) 458-2801, extension 2980.

Very truly yours,

[

T' athy J. Tulon ation Manager Braidwood Nuclear Generating Station TTUthMhN013 &w Attachment cc: Senior Resident Inspector - Braidwood Braidwood Project Manager - NRR Regional Administrator - Rill