ML17252A899

Letter Informing of 06/01/1973 Occurrence of One of Two Motor Actuators (for MOV 851A), Which Controls the Flow Path from Pump No. 22 to Supply Either Injection Header, Improperly Moved to a Closed Position - Indian Point Unit 2

ML17252A899
Person / Time
Site:	Indian Point
Issue date:	06/11/1973
From:	Caldwell W Consolidated Edison Co of New York
To:	O'Leary J US Atomic Energy Commission (AEC)
References
Download: ML17252A899 (2)

Text

William E. CaldwellA Vice President ~

Consolidated Edison Company of New York, Inc. Reguratory fire .f>f; 4 Irving Place, New York. N Y 10003 Telephone (212) 460-5181 June 11, 1973 Re*:. Indian Point Unit No. 2 AEC Docket No. 50-247 Facility Operating License DPR-26 Mr. John F. O'Leary, Director Directorate of Licensing U. S. Atomic Energy Commission Washington, D. C. 20545

Dear Mr. O'Leary:

The following report of Abnormal Occurrence No. 3-2-7 is pro-vided pursuant to the requirements of Section 6.6.1.B of the Technical Specifications to Facility Operating License No.

DPR-26.

On June 1, 1973, at 0202 hours0.00234 days <br />0.0561 hours <br />3.339947e-4 weeks <br />7.6861e-5 months <br />, automatic safety injection was initiated as a result of a spurious signal from the high steam line flow logic. By design, this signal caused a trip of the reactor which at the time was operating at essentially zero power for physics testing. The three high head safety injection pumps started as expected; however, one of two motor actuators (for MOV 851A), which controlsthe flow path from pump No. 22 to supply either of the injection headers, improperly moved to a closed position. *

• Mr. A. Fasano of the Region I Regulatory' operations Office of the U. S. Atomic Energy Commission was notified by telephone on June 1, 1973 of the occurrence. In addition, a telegram was sent to the Director of the Region I Office, Mr. J. P. O'Reilly on the same date to-confirm the notificatiof?..

Investigation into the cause of the improper operation of MOV 851A revealed that the fault was due to a logic malfunction. Normally, MOV 851A would only be required to close if high head pump No. 23 failed to start. The logic circuitry that furnishes this pro-tection includes a timer component which served to delay actu-ation of the particular MOV until six seconds after the initiation of the safety injection signal. This timing, however, did not allow sufficient time for pump No. 23 to start in this instance *.

Instead, the logic controlling the actuation of MOV 851A sensed that the pump had not yet started and supplied a closing signal.

To prevent this situation from recurring, the.timers in the operating logics for MOV 851A and B were reset for 15 seconds.

It is noteworthy, that on June 6, 1973, following another simi-3830

Mr. John F. O'Leary .:..2- June 11, 1973

• Re: Indiari Point Unit No. 2 AEC Docket No. 50-247 Faciiity Operating License DPR-26 larly spurious' safety injection signal, these.logic circuits operated pro.p~rly (i.e., all, ~hree high head pumps started and MOV 851A and B remained in their proper, open position).

There are no significant safety implications related to this occurrence because all three. high head pumps did, in fact, start and render both headers** capable of supplying safety injection flow. Furthermore, though MOV 851A and B do, under certain circumstances, operate automatically in the closed direction, they can at any time be reopened manually, should it be necessary. In light of these reasons, therefore, it is considered. that the safety of the facility was not_ .compro-mised.

Our Nuclear Facilities Safety Committee has reviewed the circum-stances of this occurrence and concurs that it does not represent a significant hazards consideration.

Very truly yours ljc