ML20003H993
| ML20003H993 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 05/04/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8105080299 | |
| Download: ML20003H993 (2) | |
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i SOUTH CAROLINA ELECTRIC a GAS COMPANY POST OFFICE 80x 784 CotunelA, SOUTH CAROLINA 29218 we. NU'.N$fe"i.co.
May 4, 1981 A'o-wo. o d
Mr. James P. O'Reilly, Director ji (p, [
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'2 U. S. Nuclear Regulatory Commission b
V Region II, Suite 3100 A#
- p 101 Marietta Street, N. W.
g Atlanta, Georgia 30303 9 f,
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Subject:
Virgil C. Summer Nuclear Station Docke No. 50/395 Significant Deficiency - Failure of The Chilled Water System Centrifugal Chiller Unit (80-16-04)
Nuclear Engineering File 14.553
Dear Mr. O'Reilly:
On May 20, 1980, an interim report was written on the subject significant i
deficiency. 'the purpose of this letter is to inform you of the permanent corrective action for this significant deficiency.
The low flow cutout in the Service Water to the Chilia Condenser has been deleted. Motor operated, ASME Section III Code Class 2, active, 1E qualified i
butterfly valves have been installed in the Service Water inlet to the Chillers which 'OPEN' when the Chiller starts running and ' SHUT' when the Chiller stops running.
An administrative controls program has been instituted through general operating procedures to regulate flow to the operating Chiller in order to mair~
l tain proper conditions for continuous Chiller operation. Similar provisions are l
made for the idle Chiller to er._ce automatic start and operation in the event conditions require the idle f. hiller be put in service, particularly in response
(
to an Engineered Safeguards (ESF) actuation.
l t
To provide added reliability of the administrative controls program, a l
dual range temperature alarm for both high and low temperature conditions in the Service Water return from the Chiller has replaced the single setpoint high temperature alarm.
The FSAR and System Descriptior are being changed to reflect the hardware changes, additional surveillance requirements and changes in system operation.
l The described permanent corrective action is in progress and completion is l
anticipated by June 1, 1981.
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t. James P. O'Reilly May 4, 1981 Page Two The subject deficiency has been discussed at great length with Gilbert Associates, Inc., the Architect / Engineer, with regard to cause and corrective action. It has been determined that the cause of this deficiency was an over-attentiveness to post accident conditions when specifying the minimum temperature of the inlet water to the Chillers without due regard for normal operating con-ditions.
In order to prevent recurrence of this type of deficiency, the incident has been discussed with cognizant Nuclear Engineering personnel and the signif-icance of normal operating as well as accident conditions have been emphasized.
Furthermore, similar discussions have been conducted by cognizant engineering personael at Gilbert Associates, Inc.
Additional action to ensure the effectiveness of other safety-related systems has been an evaluation of systems and components for similar susceptibi-lity as found with the Chillers. This evaluation has determined that the design of these systems and components has considered all operating conditions.
This letter is considered to be a final report on the subject deficiency.
If you have any questions or if I may be of further assistance on this matter, please call me.
Very truly yours, T. C. Nichols, Jr.
MDQ:TCN:glb cc:
V. C. Summer G. H. Fischer T. C. Nichols, Jr.
O. W. Dixon, Jr.
C. A. Price D. A. Nauman W. A. Williams, Jr.
R. B. Clary A. R. Koon A. A. Smith H. N. Cyrus J. B. Knotts, Jr.
J. L. Skolds B. A. Bursey O. S. Bradham M. D. Quinton J. E. Mabon Document Management Brancl.
(55e/21/LER Only)
I&E (Washington)
ISEG NPCF File PRS
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