ML20003D646
| ML20003D646 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/23/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103300070 | |
| Download: ML20003D646 (1) | |
Text
-
SOUTH CAROLINA ELECTRIC a GAS COMPANY Post orrsct oox 764 COLUM8sA, SOUTH CAROLINA 29218 h
T. C. NicHots.Ja.
March 23, 1981
^
Wet Passiot. a.o Gacup Estcums j\\
9
((
Nvet:4m 0.caances 2 77g u.s kgp[g -
I Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Boron Dilution Event
Dear Mr. Denton:
Recently, in discussion with the Reactor Systems Branch regarding boron dilution events, it was noted that insufficient times are available for operators to take. required actions in two of the events which were evaluated. SCE&G will resolve the matter by increasing the shutdown margin from 1%$ for modes 4 and 5 to2%$andbychangingthesetpointonthesourcerangeinstrumentationfrom5 times background to 2 times background. These changes will result in increasing the times from alarm to operator action to approximately 10 minutes. The start-
. up case in the FSAR will be rewritten to better describe the event where, in fact, no problem really exists. Additional information to better describe the refueling case and to justify the use of 150 gpm for flow from the reactor make-up tank will be provided later.
When details of our solution are finalized, you will be informed. If you have any questions, please let us know.
Very truly yours,
[
T. C. Nichols, Jr.
RBC:TCN:glb cc:
V. C. Summer H. N. Cyrus G.-H. Fischer
-J.
B. Knotts, Jr.
T.'C. Nichols, Jr.
J. L. Skolds C. A. Price B. A. Bursey D. A. Nauman O. S. Bradham-W. A. Williams, Jr.-
ISEG
.R. B. Clary PRS A. R. Koon NPCF A.'A.-Smith File 4
82 0s a n no7o.
-