ML19105A198
| ML19105A198 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/11/1975 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Moseley N NRC/RGN-II |
| References | |
| Serial No. 794 | |
| Download: ML19105A198 (2) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY.
R:iOHMOND,VIROiNIA 23261
- \\
Mr. Norman C. Moseley, Director {
Off ice of Inspection and Enf orcenf.. 1.\\
'Mali *se,ii<>n U.S. Nuclear Regulatory Commissiorl.,,)t(~' _
-P9c1<oirci.h, Region II - Suite 818
- c:j.
230 Peachtree Street, Northwest
- .;~.~:/ ', i,&;,'*
Atlanta, Georgia 30303 Nos.
License Nos.
Dear Mr. Moseley:
The purpose of this letter is to document discussions,vh.ich have been held with members of your staff concerning the steam generator tube phenomena referred to as 11denting 11 and to apprise you of the current developments as we know them.
During the current refueling outage on Unit No. 1, inspections were con-ducted on the steam generator tubes to acquire additional informat:i.on con-cerning "denting." As.you are probably aware, steam generator tube diameter reductions, i.e.
11denting, 11 have been experienced at a number of operating nuclear power. otations.
Because of the generic nature of the phenomena, the
. nu.clear steam supply system manufacturer, Westinghouse Electric Corporation,
- f.s doi.ng extensive invest:f.gations and studies into the matter, Enclosed here-with are two Technical Bulletins prepared by Westinghouse summ.nr:lzing the 11denting" phenomena.
A meeting between the Regulatory Staff and representatives from Westing-house was held in Bethesda, Maryland on November 21, 1975 to discuss 11denting 11 on a generic basis.
I understand that a representative from Region 11 was in attendance at that.meeting.
AB a result of the meeting, it was agreed that Westinghouse would prepare a topical report on "denting" and would apprise the Regulatory Staff of their proposed investigative program.
AB related to our units, the inspections ~onducted on the Unit No. 1 steam generator tubes indicate that there is significant "denting."
The moot severe "denting" has occurred on steam gene-rator "A 11
- Thea data obtained during the inspections are presently being evaluated to quantify the amount of denting which has occurred.
In an attempt to minimize further dentirig, we have c.hanged our met-hod for controlling feedwater pH by changing from annuonia to cyclo-hexylamine on both units.
I e
Mr. Norman c. Moseley Fage 2 Both tbe Station 'tluclear Safety and Operating Committee and the System Nuclear Safety and Operating Committee have reviewed the matter of 11denting.
11 We are continuing to follow the generic implications of this phenomena and will continue to apprise you and your.staff of significant ~evelopments *.
Attachments cc:
Mr. Robert W. Reid \\./'
Very truly yours,
~.2Y;.~tCt/;la/
C. M. Stal 0lings Vice President-Power Supply and Production Operations
.;