ML17255A227
| ML17255A227 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 06/14/1983 |
| From: | Maier J ROCHESTER GAS & ELECTRIC CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8306220022 | |
| Download: ML17255A227 (4) | |
Text
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REGULATOR'f
. FORMATION,DISTRIBUTION S EM (RIDS)
AGCESSION NBR '8306220022 DOO, DATE;.83/06/14 NOTARIZED!
NO DOCKET ¹ FAGIL:50 244 Robert Emme,t Gi.nna.Nuclear Plantr Unfit li'Rochester G
05000244
'AOTH ~ NAME au THOR aF F ILIATION MAIERtJ ~ Ee Rochester Gas 8<<Electric <Corp, RECI'Pe NAME RECIPIENT AFFILIATION ORUTGHF IELDg D ~
Operating Reactors Branch 5
SUBJECT:
Discusses steam generator s'leeving.eddy current exam. Util pursuing improvementIs'in, techniques w/goal of improvi.ng'ensitivity by mixing frequencies for unwanted signal
~suppression 8 alternate probe designs, DISTRIBUTION "COPE!
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~COPIES RECEIVED LTR
=ENCL SIZEt TITLE:
OR Submittal:
Steam Generator Sleeving Review for PNR'.s NOTES;NRR/DL/SEP icy 05000244 RECIPIENT IO CODE/NAME NRA ORB5 BC 01 INTERNAL: AEOD 16 IE/'DEPER.D IR NRR/DK/MEB 06 NRA/DL/DRAB 10 NR<
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-'COPIES LTTR ENCL
'RECIPIENT ID CODE/NAME ELD/HDS4
- 13 NRR/DE/CEB 08 NRR/DE/MTEB 05 NRR/DS I/AEB
-09 NRR/DSI/RAB 07 RGN1 12 COPIES I.TTR ENCL 1
1 1
1 2
1 EXTERNAL! ACRS 17 NRC PDR 08 NTIS 15 NOTES'0 LPDR NSIG 04 14
>TOTAL NUMBER OF COPIES REQUIRED:
LTTR 31 ENCL
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~ 89 EAST AVENUE, ROCHESTER, N.Y. 14649 JOHN E. MAILER Vice Preeident June 14, 1983 Tci.cpHoNE
- Ra* coo@ 7ie 546-2700 Director of Nuclear Reactor Regulation Attention:
Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch No.
5 U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Steam Generator Sleeving Eddy Current Examination R. E. Ginna Nuclear Power Plant Docket No. 50-244
Dear Mr. Crutchfield:
As previously discussed,
'the eddy current examination of the expanded braze region of a steam generator sleeve is performed utilizing a multifrequency technique with a,radially driven differential coil design probe.
This technique <has a sensitivity level that allows for the detection of, as a minimum, a
40%
through wall defect on either the tube or the sleeve.
Calibration for this examination has been performed on a
40% through wall x 0.1875 inch diameter flat bottom hole.
We believe this technique will also detect a
30% through wall defect in the sleeve as evidenced by'he fact that the inspection identifies the evacuated braze rings.
Due to the lower frequency used for the parent tube examination, there is minimum phase spread which makes exact depth determinations difficult, as previously reported.
After further discussions with members of your staff on examination sensitivity, we would like to document the fact that we are pursuing improvements in our techniques with the goal of improving the sensitivity.
This includes looking at mixing frequencies for unwanted signal suppression, alternate probe designs to affect the same result, and improved interpretation methods (e.g., digitalization). It is our intention that the improved technique would be used for inspection at our next refueling outage.
If the mixing or improved interpretation technique is the method selected for improving sensitivity, then the method will be used with the data from the inspection of the upper joint of brazed sleeve tubes from the current outage to provide a baseline.
We will notify you of the results investiga-tion prior to our next scheduled refueling outage.
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Very truly yours, J hn E. Maier
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