ML20140D015

Ro:On 860314,safety Injection & Subsequent Reactor Trip Occurred Due to High Steam Flow & Low Steam Line Pressure Signals.Cause Unknown.Sys Returned to Normal Status After Protection Sys Completed Safety Function

ML20140D015
Person / Time
Site:	Diablo Canyon
Issue date:	03/17/1986
From:	Thornberry R PACIFIC GAS & ELECTRIC CO.
To:	Briam W SAN LUIS OBISPO, CA
References
NUDOCS 8603250553
Download: ML20140D015 (2)

Text

, PACIFIC GAS AND E LE C T RI C C O M PANY DIABLO CANYON POWER PLANT lllllllgg PO. Box 56 Avila Beach. Cahtomia 93424 *(805) 595-7351 k" " "

"mW R C THORNBERRY PL ANT MANAGER March 17, 1986 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 summary report concerning the following Unusual Events at the Diablo Canyon Power Plant site.

On March 14, 1986, while Unit I was increasing power fron 98% to 100% power, a safety injection and subsequent reactor trip occurred from high steam flow ard low steam line pressure signals.

An Unusual Event was declared by the Shift Forenan at 1428 PST and emergency notifications were started.

The Unusual Event was concluded at 1500 PST, March 14, 1986 and all response organizations were notified. A second Unusual Event was declared at 1556 PST when a second Unit 1 safety injection occurred in response to high steam flow and low temperature signals while returning all systens to their normal status.

The Unusual Event was concluded at 1559 PST, March 14, 1986 and all response organizations were nntified.

After the protection systen completed its safety function, all systems ware returned to their normal status. These events have in no way affected the health and safety of the public and no discharge of radioactive materials was made to  !

the environment. )

j Sincerely, 8603250553 860317 , /

PDR ADOCK 05000275 (

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Robert C. Thornberry p RCT:jhr

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f1 (Tir. W1VlMam Briam -rd- Warcbh XF, Mn;Lt s

-a cc Mr. Benjamin P. Tong, Chief Nuclear Power Plant Planning P. O. Box 9577 Sacramento, CA 95823 Mr. John B. Martin, Administrator U 5. Nuclear Regulatory Comission, Region V 1450 Maria Lane, Suite 210 Walnut Creek,.CA 94596-5368 Mr. George Whiting, Sheriff San Luis Obispo County P. 0. Box 32 San Luis Obispo, CA 93401 Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing Office of Nuclear Reactor Regulatior.

V. S. Nuclear Regulatory Commissior Washington, D. C. 20555

. Director, .0f fice of Management Information and Progran Control U. S. Nuclear Regulatory Commission Washington, D. C. 20555 DC0480 2