ML20084A496

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AO 3-2-10:on 730802,discovered That Limiting Safety Sys Setting of Channel III of overpower-overtemp delta-T Reactor Trip Circuitry Below Tech Spec Requirements.Caused by Improper Adjustment of Channel.Channel Recalibr
ML20084A496
Person / Time
Site: Indian Point Entergy icon.png
Issue date: 08/16/1973
From: Zarakas P
CONSOLIDATED EDISON CO. OF NEW YORK, INC.
To: Oleary J
US ATOMIC ENERGY COMMISSION (AEC)
References
AO-3-2-10, NUDOCS 8304050208
Download: ML20084A496 (2)


Text

r me q Peter Zarakas

, ,,[ Vice Pres @nt p

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% Consolidated Edison Company of New York,Inc.

"T ~ I s 4 living Place. New York, N.Y.10003 G \. -

fJ' a Telephone (212) 460 5042 Q7 ',\

ff \ h August 16, 1973 i b- Re: Indian Point Unit No. 2

[' g fl3 ' ~ ~ T.9 .

, AEC Docket No. 50-247

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Facility Operatiag

1. , , -; 1., j( , License DPR-26

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- fy Mr. John F. ,0' Leary Directorate of Licensing U. S.- Atomic Energy Commission Washington, D. C. 20545

Dear Mr. O' Leary:

The following report of Abnormal Occurrence No. 3-2-10 is provided pursuant to the requirements of Section 6.12.2 (a) of the Technical Specifications of Facility Operating License DPR-26.

On August 2, 1973 during the performance of periodic test and calibration pr,ocedure PT-MI, it was discovered that the limiting safety system setting of Channel III of the Overpower-Overtemperature Delta-T Reactor Trip Circuitry for (qp - qb)>AI2 was below that required by Technical Specif2. cation 2.3.1.B. At the time of the occurrence, the reactor was shutdown with the primary coolant system at 350or.

The discrepancy is believed to have resulted from an 5 improper adjustment of the channel. To correct the situ-ation, Channel III was recalibrated and tested satisfac-torily. During future calibration checks, particular attention will be paid to these instruments to enable a ..

more problem.

definitive determination as to the cause of the In considering the safety implications of the occurrence, it should be noted that the discrepancy in this instrument was detected during a routine surveillance test, which is performed monthly. Furthermore, there are three other  :

trip circuits (Channel I, II and IV) providing complete reactor protection against an excessive axial flux tilt.

Channel III, incidentally, was still operationnl for

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sass ,L COPY SENT REGION

                                                                                       .........m O                                  O Mr. John F. O' Leary                        August 16, 1973 Re:     Indian Point Unit No. 2 AEC Docket No. 50-247 Facility Operating License DPR-26 e

an axial tilt of qb > 9t For these reasons, the safety implications to the occurrence are considered to be negligible. Very truly yours, Copy to Mr. James P. O'Reilly ) s e f 9

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