ML18095A665
| ML18095A665 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/28/1990 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLR-N90229, NUDOCS 9101080280 | |
| Download: ML18095A665 (4) | |
Text
Public Service Electric and Gas Company Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-4800 Vice President - Nuclear Operations DEC 2 B 1990 NLR-N90229 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
STEAM G~NERATOR SURVEILLANCE REQUIREMENTS REQUEST FOR ADDITIONAL INFORMATION LICENSE CHANGE REQUEST 88-09 SALEM GENERATING STATION UNIT 1 DOCKET NO. 50-272 In letter dated August 28, 1990, you requested additional information concerning Public Service Electric & Gas Company's (PSE&G) license change request 88-09, steam Generator Surveillance Requirements.
In response to that letter, PSE&G hereby submits the following information.
- 1.
In Salem Unit No. 1, a 100% eddy current baseline examination was performed on all four steam generators. shows the number of tubes which received inservice inspection by generator number.
Most of the Steam Generator tubes have been examined at least one time.
Denting in these tubes has been measured in terms of restriction to various sized eddy current probes.
In addition, the amount of denting has been determined in most cases by recording amplitude (voltage) of response to a standard bobbin coil probe on the 400 KHz channel.
- 2.
Our assumption that tube denting has been arrested, or at least is not progressing significantly, is based on historical data that shows that:
- a.
No more than 80 or 90 tubes in each steam generator have restricted a standard.720" diameter coil probe.
- b.
No more than 5 or 6 tubes in each steam generator have restricted a.700" diameter probe; 6 out of 8 steam generators at both Salem Units 1 and 2 have no tubes which restrict a.700" diameter probe except in the U Bend region of low row tubes.
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Document Control Desk NLR-N90229 2
DEC 2 8 1990
- c.
There has been no consistent pattern of increase in the number of tubes restricted since the plants went on line.
In some cases, the number of restrictions has gone down, reflecting improvements in probe design and probe pushing equipment and technique over the years.
We believe that many of the restrictions and dent signals are due to mechanical dents caused by shipping and handling, as indicated by our pre=service baseline data.
- d.
Flow slot photography is performed during every outage and has yet to show any signs of "hour-glassing".
- e.
PSE&G has taken a pro-active approach toward ensuring optimum water chemistry and other controls to mitigate denting from the formation of magnetite, including virtual elimination of copper bearing alloys from the secondary water train, retubing the condensers with titanium, use of full flow condensate polishers, use of AVT water treatment, 100% sludge lancing every refueling outage, etc.
- f.
Use of profilometry probes has been limited, in view of the above factors, but when used it has indicated no significant distortion of tubes.
- 3.,* PSE&G considers restriction to a.540 11 diameter probe to be the plugging limit for a dented tube.
This is based on a recommendation from the steam generator manufactu~er. Tubes restricting a.720" diameter probe, but passing probes larger than.540" diameter are recorded and tracked for any change in restriction. contains the number of tubes that have been eddy current inspected during each outage.
Should there be any questions with regard to this submittal, please do not hesitate to contact us.
Sincerely, Attachment
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Document Control Desk NLR-N90229 c
Mr. J. c. Stone Licensing Project Manager Mr. T. Johnson Senior Resident Inspector 3
Mr. T. Martin, Administrator Region I Mr. Kent Tosch, Chief New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625 DEC 2 8 1990
NLR-N90229 BASE 1st 2nd STEAM LINE RFO RFO GENERATOR 1976 4/79 10/80
- 11 3388 454
- 12 3388 292
- 13 3387 617
- 14 3387 288 64 STEAM GENERATOR TUBE INSPECTION EDDY CURRENT INSPECTION
SUMMARY
TOTAL NUMBER OF TUBES INSPECTED SALEM UNIT NO. 1 3rd 4th 5th 6th RFO RFO RFO RFO 7th RFO 1/82 11/82 4/84 4/86 11/87 850 1225 419 1120 1220 3346 1405 1221 1221 1561 1214 3332 LCR 88-09 8th FORCED RFO 4/88 4/89 1402 205 180 207 710
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