ML17252A894

Letter Informing of 08/02/1973 Discovery of the Limiting Safety System Setting of Channel III of the Overpower-Overtemperature Delta-T Reactor Trip Circuitry for Q/T - Q/B) Was Below Technical Specification - Indian Point Unit 2

ML17252A894
Person / Time
Site:	Indian Point
Issue date:	08/16/1973
From:	Zarakas P Consolidated Edison Co of New York
To:	O'Leary J US Atomic Energy Commission (AEC)
References
Download: ML17252A894 (2)

Text

Peter Zarakas Vice President

~egulatory. D.ock~t *fBI August 16, 1973 Indian Point Unit No. 2 AEC Docket No. 50-247 Facility Operating

'License DPR-26

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, 19 7 3, during the performance o.f periodic test- .

and calibration procedure PT-MI~ it was discovered that the limiting safety system setting of Channel III of the Overpowe*r-Overtemperature Del ta-T Reactor Trip* Circuitry for (q1= - qb) > ~I 2 was below that required by Technical Specification 2.3.1.B. At the time of the occurrence, the reactor was shutdown with the primary* coolant system at 350°F.

The discrepancy is believed-to have resulted from an improper adjustment of the channel. To correct the situ-

.at ion, Char:inel*III was recalibrated and tested satisfac-torily. During future calibration checks, particular attention will be paid to t~ese instruments to enable a more definitive determirtation as to the cause of the problem.

• 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 operational for

Mr. John F. O'Leary August 16, 1973

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~e: Indian Point Unit No. 2 AEC Docket No. 50-247 Facility Operating License DPR-26 an axial tilt of qb > qt. For these reaso'ns, the safety implications to the occurrence are considered to be negligible.

truly yours, Copy to Mr. James P. O'Reilly