ML20209C292

Submits Daily Highlight.On 840506,reactor Tripped Due to Spurious Trip Signal from One Instrumentation Channel. Component Replaced & Tested.On 840508,reactor Tripped Due to SI Resulting from Opening of Condenser Steam Dump Valve

ML20209C292
Person / Time
Site:	05000000, Diablo Canyon
Issue date:	05/09/1984
From:	Schlierling H Office of Nuclear Reactor Regulation
To:	Case E, Harold Denton, Edison G NRC
Shared Package
ML082410749	List: ML20209A984 ML20209B531 ML20209B624 ML20209B724 ML20209B847 ML20209B894 ML20209C131 ML20209C225 ML20209C292 ML20209C320 ML20209C516 ML20209C643 ML20209C669 ML20209C675 ML20209C698 ML20209C705 ML20209C710 ML20209C715 ML20209C720 ML20209C836 ML20209C847 ML20209C848 ML20209C876 ML20209C881 ML20209C908 ML20209C921 ML20209C969 ML20209C975 ML20209C981 ML20209C993 ML20209D004 ML20209D012 ML20209D018 ML20209D030 ML20209D038 ML20209D044 ML20209D045 ML20209D071 ML20209D089 ML20209D114 ML20209D127 ML20209D130 ML20209D135 ML20209D139 ML20209D146 ML20209D154 ML20209D211 ML20209D218 ML20209D230 ML20209D235 ... further results
References
FOIA-86-197 NUDOCS 8704280641
Download: ML20209C292 (1)

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'MAY S, MEMORANDUM FOR:

H. R. Denton, NRR E. G. Case, NRR G. Edison, TOSB, NRR D. G. Eisenhut, DL R. A. Purple, DL T. Novak, DL H. Thompson, DHFS R. Vollmer, DE R. Mattson, DSI T. Speis DST B. Snyder, TMIPO, NRR G. Holahan, ORAB G. Lainas DL F. Miraglia, DL THRU:

George W. Knighton, Chief

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Licensing Branch No. 3 Division of Licensing FROM:

Hans Schierling, Project Manager Licensing Branch No. 3 Division of Licensing 1

SUBJECT:

DAILY HIGHLIGHT DIABLO CANYON On May 8,1984, at approximately 1:10 pm PDT while at low power the reactor tripped due to a SI as a result of opening of the condenser stean dump valve.

The valve opened due to a spurious signal to valve instrumentation. The opening of the valve caused a valid high steam flow condition. Investigation is being conducted to determine if the spurious signal was the result of maintenance work being performed by I&C technicians. Estimated time to restore criticality is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

l Previously, on May 6,1984 at approximately 10:00 pm PDT while at low power the reactor tripped due to a spurious trip signal from one instrumentation i

channel. A component was replaced and tested. The reactor went critical again on May 8, 1984 at 4:00 am PDT.

%M Al Hans Schierling, Project Manager Licensing Branch No. 3 Division of Licensing i

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9 8704280641 870417 PDR FOIA HOLMES86-197 PDR

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