ML19253C374

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Forwards IE Info Notice 79-27, Steam Generator Tube Ruptures at Two PWR Plants. No Response Required
ML19253C374
Person / Time
Site: FitzPatrick Constellation icon.png
Issue date: 11/16/1979
From: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To: Leonard J
POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
References
NUDOCS 7912050278
Download: ML19253C374 (1)


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Docket No. 50-333 Power Authority of the State of New York James A. FitzPatrick Nuclear Power Plant ATTN:

Mr. J. D. Leonard Resident Manager P. O. Box 41 Lycoming, New York 13093 Gentlemen:

The enclosed IE Information Notice No. 79-27 provides information with regard to the sequence of events that followed incidents involving steam generator tube ruptures at two PWR units.

If you have any questions regarding this matter, please contact this office.

Sincerely, n'd2- }//, kO?b i -

Boyce H. Grier

[w Director

Enclosures:

1.

IE Information Notice No. 79-27 2.

List of Recently Issued Information Notices CONTACT:

W. H. Baunack (215-337-5334) cc w/encls:

George T. Berry, Executive Director P. W. Lyon, Manager - Nuclear Operations A. Klausmann, Director, Quality Assurance 1503 051 M. C. Cosgrove, Quality Assurance Supervisor J. F. Davis, Chairman, Safety Review Committee V. J. Cassan, Assistant General Counsel G. M. Wilverding, Licensing Supervisor 7912050 2 77

ENCLOSURE 1 SSINS No.:

6870 Accession No.:

7910250488 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON D.C.

20555 IE Information Notice No. 79-27 Dato:

November 35, 1979 Page 1 of 9 STEAM GENERATOR TUBE RUPTURES AT TWO PWR PLANTS Description c' Circumstances:

In recent months two incidents involving steam generator tube ruptures have occurred.

In both instances, the units were cooled down and placed in the residual heat removal mode with existing procedures.

Event of June 25, 1979 at the Doel 2 Nuclear Power Plant in Belgium The first event occurred on June 25, 1979, at the Doel 2 nuclear power plant in Belgium.

The Doel unit is a 390 Mwe Westinghouse two-loop reactor.

The event consisted of a rupture of several tubes in the loop B steam generator.

The resultant leakage between the primary and secondary systems was estimated to be 125 gpm.

The event started when the plant was heated up after a shutdown caused by a malfunction of the main steam isolation valve.

At the time of the incident the primary coolant pressure was:

2233 psi and the temperature:

491 F.

The reactor remained subcritical throughout the event.

The first indication of abnormal behavior was a rapid decrease of the primary system pressure (approximately:

28 psi / min.).

This was followed by the sequence of events listed below:

Time, min.

1.

Increase of charging flow demand, requiring startup of a second

1. 8 charging pump.

2.

Automatic isolation of the CVCS letdown line.

2.4 3.

Shut off of the pressurizer heaters due to low liquid level in the 2.4 pressurizer.

DUPLICATL DOCUMENT Entire document previously entered into system under:

-)?/o Mo 483 1503 052 aNo No. of pages:

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