ML20100K224
| ML20100K224 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/26/1984 |
| From: | Thornberry R PACIFIC GAS & ELECTRIC CO. |
| To: | Briam W SAN LUIS OBISPO, CA |
| References | |
| NUDOCS 8412110006 | |
| Download: ML20100K224 (2) | |
Text
.3 PACIFIC OAS AND E LE C T RIC C O M PANY DIABLO CANYON POWER PLANT ppg RO. Box 56
- Avila Beach. Cahfomia 93424 (805) 595-7351 i
R.C. THORNBERRY
^ ^ " ' " ^ * ^ " ' "
November 26, 1984 Mr. William Briam, Administrator San Luis Obispo County Administrative Office County Government Center San Luis Obispo, CA 93408
Dear Mr. Briam:
Pursuant to NUREG-0654, Revision 1, Appendix 1, the following is a sumary report concerning an Unusual Event at the Diablo Canyon Nuclear Power Plant site.
On November 24, 1984, a malfunction of the turbine control system resulted in the opening of the 10 and 35 percent steam dumps due to sudden load rejection. This led to a Hi-Hi Steam Generator Level Turbine trip, resulting in a Reactor trip.
In accordance with the Trip Recovery Procedure (EP OP-0), the steam dump controller was switched to Pressure Control. While in the Pressure Control Mode the steam dump cooldown valves opened producing a high steam flow safety injection signal. The safety injection signal caused the Emergency Core Cooling System to initiate and discharge to the Reactor Coolant System.
This condition caused an alarm at the state Office of Emergency Services.
An Un w.al Event was declared by the Shift Foreman at 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br /> and emergency notification was started. After the protection system completed its safety functions, all systems were returned to their previous status.
The Unusual Event was concluded at 1639 hours0.019 days <br />0.455 hours <br />0.00271 weeks <br />6.236395e-4 months <br />, November 24, 1984 and all response organizations were.iotified.
This event has in no way affected the health and safety of the public and no discharge of radioactive materials were made to the environment.
i Sincerely, s/ s R. C. THORNBERRY r
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2 Mr. William Briaa November 26, 1984 cc: Mr. William Medigovich, Director California Office of Emergency Services P. O. Box 9577 Sacramento, CA 95823 Mr. John J. Kearns California Office _ of Emergency Services P. O. Box 9577 Sacramento, CA 95823 Ms. Ann Vasquez California Office of Emergency Services P. O. Box 9577.
Sacramento, CA 95823 Mr. John B. Martin, Administrator U. S. Nuclear Regulatory Comission, Region V 1450 Maria Lane, Suite 210 Walnut Creek, CA 94596-5368 Mr. George Whiting, Sheriff San Luis Obispo County P. O. Box 32 San Luis Obispo, CA' 93401 Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comission Washington, D. C.
20555 Director, Office of Management Information and Program Control U. S. Nuclear Regulatory Comission Washington, D. C.
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