ML19344D645
| ML19344D645 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 04/15/1980 |
| From: | Mccrary D SOUTHERN COMPANY SERVICES, INC. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8004250390 | |
| Download: ML19344D645 (4) | |
Text
Sou:nem Comeany Ssrvic s. Inc.
Pes: office Box 2c25 5
- vagnam. A:acama 35202 Te:cenena 205 870-6131 Douglas L. Mccrary Executive Vice President the southem electnc neem April 15,1980 Docket Number:
50-321 United States Nuclear Regulatory Commission Office of Inspection and Enforcement Region II - Suite 3100 101 Marietta Street, N.W.
Atlanta, Georgia 30303 Attention: Mr. James P. O'Reilly Gentlemen:
On April 11, 1980, it was reported to your office that a potent,sl cefect existed in the cooling water supply on the residual heat removal fervice water pump motors' lube oil coolers at the Edwin I. Hatch Nuclear Plant, Unit 1.
Southern Company Services, Inc., as architect engineer for Georgia Power Company, has conducted an evaluation for a substantial safety hazard. A conclusion was reached that a substantial safety hazard did exist.
This reponse contains no proprietary information and may be placed in the NRC Public Document Room upon receipt.
Very truly yours, dXk lw Enclosure cc:
U. S. Nuclear Regulatory Commission Georgia Power Company R. J. Kelly J. H. Miller, Jr.
F. G. Mitchell, Jr.
C. F. Whitmer
'g W. A. Widner C. Bellflower 5
L. T. Gucwa
/
M. Manry
// /
C. R. Miles, Jr.
R. Staffa 8004250310
=
I United States Nuclear Regulatory Comission April 15,1980 Page 2 cc: Southern Company Services, Inc.
R. E. Conway R. A. Thomas E. L. Williamson Ozen Batum W. F. Garner L. W. Williams l
T
SUBSTANTIAL SAFETY HAZARD IN RHR SERVICE WATER PUf1P MOTORS COOLING WATER SUPPLY LINE Initial Report:
On April 11, 1980 the following personnel at Southern Company Services reported to the NRC Region II Office the existence of a possible defect in the cooling water supply line to the residual heat removal service water pump motor's lube oil coolers at the Edwin I. Hatch Nuclear Plant -
Unit 1.
Mr. Ozen Batum - Manager of Nuclear Safety & Licensing Mr. William F. Garner - Manager of Nuclear Plant Support Mr. Randy Dewberry - Project Engineer, Nuclear Plant Support Address:
Southern Company Services, Inc.
800 Shades Creek Parkway P.O. Box 2625 Birmingham, Alabama 35209 Bac kgr;,und:
During a review of the Edwin I. Hatch-Unit 1 plant service water rystem, the following potential defect was identified. The RHR service water pump motors have a single cooling water supply line. This line supplies cooling water to the lube oil coolers.
The source of cooling water is a intertie between Division I and Division II plant service water headers.
In the event of a Division I or Division II failure, check valves are provided for isolation purposes at the connection to the Division I and Division II service water pipe. Additionally, a pressure regulator was installed in the supply line to regulate the water pressure to the lube oil coolers.
The problem that exists is that a single failure in the cooling water supply line could cause a failure of the Division I and Division II residual heat removal service water pumps for Edwin I. Hatch Nuclear Plant - Unit 1.
Evaluation:
A failure of the cooling water supply line would leave the RHR pump motor lube oil coolers without cooling water.
A'.1 indications were that the motor bearings would be damaged if the moto's run without the cooling water being supplied to the lube oil coolers. This loss of RHR cooling water would result in the exceeding of the safety limit in the facility technical speci fication.
Two potential modes of failure were identified. One mode was an active failure of the pressure regulator.
Another mode was a pioe break.
r 2
Further investigation revealed that the pressure regulator and piping were seismically supported.
Corrective Action:
The internals were removed from the pressure regulator to make it a passive component, thereby alleviating the active failure concern (PR2-R41-D107). Additionally, a pressure gauge was installed on a utility outlet near the regulator. By manually throttling valve PVl-F440A, the pressure can be kept within acceptable limits. The pressure is being i
monitored on a 24-hour a day basis.
To correct against a potential failure, the mc+or cooling water system will be divided into two separate divisions. liic discharge of the Division I Plant Service Water Pumps will be the source cf cooling water for the Division I Plant Service Water Pump Motors and the Division I RHR Service Water Pump Motors. The discharge of the Division II Plant Service Water Pumps will be the source of cooling water for the Division II Plant Service Water Pump Motors and the Division II RHR Service Water Pump Motors. The existing water line will be modified and used to supply the cooling water to Division I pump motors. A new water line will be added to supply the cooling water to the Division II pump motors. This satisfies the license requirements.
The corrective action at Plant Hatch-Unit 1 will be the responsibility of Mr. M. Manry of Georgia Power Company. Georgia Power Company is pro-curing the items necessary to modify the cooling water supply lines. The systems will be connected and placed into operation during the first unit cold shutdown after receipt of the material.
However, to further improve the system a long-tenn fix will be implemented during a scheduled refueling outage after the necessary equipment and components are obtained. This fix will consist of supplying cooling water to each division of pumps separately as it is in Hatch-Unit 2.
Sumary:
Southern Company Services, as the architect / engineer for Georgia Power Company, has evaluated this problem and has concluded that it does represent a substantial safety hazard since the failure of the cooling water supply could result in the exceeding of a safety limit as defined in the facility technical specification.
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