ML19316A617
| ML19316A617 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 09/08/1975 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19316A615 | List: |
| References | |
| NUDOCS 8001130128 | |
| Download: ML19316A617 (2) | |
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DUKE POWER COMPANY j
OCONEE UNIT 2 I
Report No.: A0-270/75-17 Report Date:_ September 8, 1975 i
l Occurrence Datet August 24, 1975 1
Oconec Unit 2, Seneca, South Carolina J
Facility:
1 Increase in Component Cooling Systec activity Identification of Occurrence:
I Conditions Prior to Occurrence:_ Unit in startup 4
Description of Occurrence:
the radiation monitor trend recorder for Oconee Unit 2 On August 24, 1975, was reviewed to determine trends which might have occurred within the past l
l indicated on process 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The Component Cooling System count rate, i
23, 1975 monitor 2RIA-50, had increased from 65,000 cpm at 0800, August to 300,000 cpm at 0900, August 24, 1975. A clearly defined step was indicated at about 0930, August 23, 1975, about 20 minutes after a reactor full power. A sample of component cooling water was trip from 99 percent immediately taken and indicated that Fluorine-18 half-life 109.8 minutes in addition to the normal background activity.
was present 24, 1975, The "A" letdown cooler was removed from service at 1045, August In order to confirm 1
and by 1400 2RIA-50 count rate had decreased slightly.
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the source of leakage, the "A" letdown cooler was placed back in service The count rate immediately increased and the l
for a short period of time.
"A" cooler was again taken out of service.
l Designation of Apparent Cause of Occurrence:
l The apparent cause of the increased activity in'the Unit 2 Component Cooling i
System is a leak in the "A" letdown cooler.
Analysis of Occurrence:
The letdown coolers are located in the Reactor Building and provide. cooling This incident resulted in an for reactor coolant prior to purification.
approximately 0.2 gal./ min. leak from the Letdown System to the Component t
l All radioactivity was contained since the Component Cooling l
Cooling System.
Both the Letdown System and Component Cooling System is a closed system.
When the leakage System remained capable of performing their design function.
was discovered, the cooler was isolated and the redundant cooler placed_in j
It is concluded that the health and safety of the public was not service.
affected by this incident.
8001130/ g
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Corrective Action:
The "A" Ictdown cooler has been taken out of service and isolated and the redundant cooler placed in service.
Repairs to the "A" letdown cooler are in progress.
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