ML20011A799

RO 335-81-46:steam Generator Tube Eddy Current Test Performed in Ctr Area of B Steam Generator to Confirm Leak Located by Helium Test.Cause Not Stated.Testing of Rows 1-18 Will Be Completed within 2 to 3 Days

ML20011A799
Person / Time
Site:	Saint Lucie
Issue date:	10/26/1981
From:	Wethy C FLORIDA POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
RO-335-81-46, NUDOCS 8111030229
Download: ML20011A799 (1)

Text

TECil/PSL #'

POST OFFICE BOX 128, FT. PIERCE, FLORIDA 33454 Ltr. Bk. #257 ,, _

g gtlN FLORIDA POWER & LIGHT COMPANY October 26, 1981 Copies to: CMW, JilB, DAS, NGR, RRJ P= q)

Offaite: JWW, COW, PLP, REU, KNH ,s

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To: Mr. J. P. O'Reilly, Director, Region II D:

Office of Inspection and Enforecement ;Q $0 Og U. S. Nuclear Regulatory Commission t7j 8/g -

Atlanta, Georgia 30303 arg to.,

From: Mr. C. M. Wethy, Plant Manager sf,. . , ,

St. Lucie Plant - DPR 67 Florida Power & Light Company h/

Miami, Florida

Subject:

MEMO FOR FACSIMILE TRANSMISSION TO CONFIRM PROMPT REFORTABLE OCCURP.ENCE 335-81-46 Steam Generator Tube Eddy Current Testing This is to confirm the telephone conversation with Mr. H. Dance at 4:15 p.m. on 10/23/81. Due to a very small tube leak located by helium testing we did Eddy Current Testing (ECT) in the " center" area of B S/G which was not part of cur original planned sample and was an area not previously extensively tested.

With a planned sample of 600 tubes (ecch S/G) to be tested we had found enough failures (degradation greater than 40% of wall thickness) to put us in Category C-3 of Tech Spec 3.4.5 which is prompt reportable per T.S. Table 4.4-2. Current results are that the tailures are concentrated in tube rows with full radius bends i.e. U shaped rather than tubes with two 90 bends. There are about 2000 of these.U bend tubes (of approxirestely 8600 total) in eacl- S/G. Based on a sinall sample, concentrated in the failure area, the defect rate is quite high as of 10/23/81. "A" S/G 2 failures of 38 tested, "B" S/G 22 failures of 120 tested. Again, this is the first time any significant ECT has been done in this area. CE states this is the first time this pattern has been seen.

Update: As of 10/26/81 "A" S/G 22 failures of 536 tested. "B" S/G 39 failures of 904 tested (4.1% and 4.3%) All but 2 failures are in rows 8-12 of the U-bend tubes; 1 is in row 13, and 1 is in row 18, the outermost U-Bend tube row.

Present plans are to complete testing in rows 1-18 over the next 2-3 days.

So far failures are in the upper bend area so the defective area is inaccessible for inspection even by pulling the tube. gp7 C. M. Wethy k gh

/6

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Plant Manager 8111030229 811026 ,,

St. Lucie Plant PDR ADOCK 05000335 S PDR , PEOPLE. . SERVING PEOPLE