ML20077C697

Special Rept Spr 910002:on 910413,area Temp of 102 F Allowed by Tech Spec 3.7.9 Was Exceeded for More than 8 H. Caused by Unavailability of Chilled Water to Room Cooler During Period Emergency Feedwater Pumps Were Used

ML20077C697
Person / Time
Site:	Summer
Issue date:	05/13/1991
From:	Skolds J SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
SPR-910002, NUDOCS 9105230073
Download: ML20077C697 (2)

Text

-

(

19VI ! f! 'O b H' $ fli b b6N b O ['h' i Y N'b k I 4

da=mb SCE&G

~

MAY l 31991 Mr. S. D. Ebneter Regional Administrator U. S. Nuclear Regulatory Commission Region !!, Suite 2900 101 Marietta Street, NW Atlanta, GA 30323

SUBJECT:

VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50/395 OPERATING llCENSE NO HPF-12 SPECIAL REPORT (SPR 910002) (ON0 910020)

This Special Report is being submitted pursuant to the requirements of Technical Specification 3.7.9, Area Temperature Monitoring, Action a.

k On April 12, 1991, the plant entered Mode 3 in support of maintenance activities associated with the secondary side of the Moisture Separator Reheaters. The plant remained in Mode 3 until April 19, 1991. During this period (April 12-19), normal Reactor Coolant System (RCS) temperature and pressure were maintained using the Main Steam Power Operated Relief Valves, while steam generator level was maintained using the Motor Driven Emergency Feedwater Pumps. At 0230 hours0.00266 days <br />0.0639 hours <br />3.80291e-4 weeks <br />8.7515e-5 months <br />, Apri! 13, the area temperature of iO2*F (Emergency Feedwater Pumps Area) a'iowed by Tecnni:?1 Specification 3.7.9 was exceeded for more than eight hour.5. The maximum area temperature recorded for the area was 106*F. The cumulative time that the areas were in excess of 102*F was calculated to be 134.7t' hours in the Turbine Driven Emergency feedwater Pump area and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> M the Motor Driven Emergency Feed *ater F.rp area.

The cause of the high temperature is attiibuted to the unavailability of chilled water to the icom cooler during the pariod the emergency feedwater pumps were in use.

On March 12, 1990, the Licensee submitteG Licensing Event Report 90-001 identifying a design deficiency per 10CFRU associated with the Chilled Water Syste'm. The evaluation of the design determir.cd that in the event of a High Energy Line Break (HELB) in the Intermediate Building, both trains of Chilled Water could be rendered inoperable. One action taken to protect the system from the deficiency was to isolate the cooling coils in the Motor Driven Emergency Feedwater Pump area. A modification correcting the identified deficiencies has been approved and scheduled for implementation during Refuel 6.

910523c073 910513 3 ADOCK 0500

{DR pg yo

...,y Mr. S. D. Ebneter SPR 910002 (ON0 910020)

Page 2 of 2 ,

f An operability and equipment qualification investigation was performed. This review of all qualified equipment in the subject area revealed that the most limiting operability temperature was 200*F (Limitorque operators). The range of operating temperatures for other equipment reviewed was determined to be 200'F-250*F. Therefore, there was no inoperable equipment during this time due to high ambient temperature. The engineering review also determined that there was no change to the qualified-life of 10CFR50.49 equipment within the

, area of high ambient temperature.

It should be noted that a similar environmental qualification review was performed as part of the Part 21 report (January 1990) identified in this report. The results of both reviews are consistent.

Should there be any questions, please call at your convenience.

Very truly yours, g

John L. Skolds RJB:JLS: led c: 0. W. Dixon Jr. Marsh & McLennan R. R. Mahan Document Control Desk R. J. White INP0 Records Center General Managers ANI Library G. F. Wunder NSRC C. A. Price RTS IONO 910020)

NRC Resident inspector file (818.05&818.08)

J. B. Knotts Jr.

i NUCLEAR EXCELLENCE - A SUMMER TRA0!! ION! l

-. -. . . - - -- . . - . . .-