ML20235Y290

Part 21 Rept Re Potential Hazard That Magnet in Class J Industrial Control Relays May Jam When Called to de-energize & Control Circuits May Not Open.Special 120-volt Coil Removed & New Relay Installed

ML20235Y290
Person / Time
Site:	Seabrook
Issue date:	10/09/1987
From:	Zerbock J TELEMECANIQUE, INC.
To:	NRC
References
REF-PT21-87-191-000, REF-PT21-87-192-000 PT21-87-191, PT21-87-191-000, PT21-87-192, PT21-87-192-000, NUDOCS 8710200292
Download: ML20235Y290 (2)

Text

l n m ~. m v s m u., w M 0CT 20 A 9 40 October 9, 1987 US Nuclear Regulatory Commission Washington, D.C. 20555 ATTN: Director, Office of Inspec* ion and Enforcement

SUBJECT:

Notification Persuant to 10CFR21 Concerning Special A.C. Coil Number 816 Used in a Type J Industrial Control Relay at the Seabrook Nuclear Station Gentlemen: l I

On August 28, 1986 New Hampshire Yankee called from Seabrook N.H. to advise i that they wished to return two Class J industrial control relays for inspection 1 and to report that the relays which are constantly energized, showed discolor-ation and embrittlement of the blue armature carrier in the magnet block.

The 131 relays installed at the site were field equipped with a special magnet coil, allowing the relay to pick-up at or below 75% of rated voltage and being capable of operating at 110% of rated voltage indefinitely.

I Upon investigation it was confirmed that the relays had the required special I operating range and that the coil withstood the increased operating temperature which results f rom magnet over-excitation. However, an armature carrier which j surrounds core and coil became discolored and embrittled in a matter of months  ;

when exposed to these temperatures continuously.

The potential hazard resulting f rom this condition is that the magnet may jam I when called to de-energize and the control circuits may not open as called for.

The product is manuf actured by Telemecanique Inc., 100 Relay Road, Plantsville, CT 06479.

Model numbers include J10A control relays having a J20M magnet block with a coil identified as 816 with 50 ohms resistance.

Corrective action has been outlined at the above listed manufacturer's facility with includes:

• Removal of the special 120V coil, detail #816 from all relay magnet blocks.

• Installation of the manufacturer's new standard 120V magnet coil, type G10JAl26 (69.2 ohms resistance).

• Equipping all relays with a minimum of two contact blocks to lower the pick-up voltage to the originally required, special value of 75% (less than 90V).

• Changing the armature carrier, P.N. 403939 to a temperature stabilized material TELEMECANIQUE INC. 2002 BETHEL ROAD,1 WESTMINSTER, MD 21157,(301) 876-2214 0710200292 871009 PDR S

ADOCK 05000443 PDR

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Page 2 Notification Persuant to 10CFR21 Concerning Special'A.C. Coil Number

.Used in a Type .J ~ Industrial Control Relay at the ' Seabrook Nuclear Station L

and_ identifying the new material by color coding. This is an extra precaution

.and will be adapted as a new standard to our relay line.

• Testing pick-up voltage - of each relay at elevated temperature to simulate performance at worst condition in operation.

'292 special coils were supplied to New Hampshire Yankee, Seabrook Nuclear Power Cenerating Station between August 23,.1985 and March 26, 1986.

Our records do not indicate shipment of like special coils to any other nuclear station using Class J industrial control relays.

' Based on this report Telemecanique Inc. believes the . reporting requirements of:  ;

10CFR21.to be complete and that no further action is planned ' or required.

Sincerely,

. C L/

Jgge H. Zer. h Engineering Managar

'l' JHZ/ jam

.cc: 'D. E. Moody, Plant Manager J. M. Vargas, Manager of Engineering R. W. Romer, Manager, Purchasing Contracts & Insurance Public Service Cc. of New Hampshire New Hampshire Yankee Division Seabrook Station, P.O. Box 300 Seabrook, NH 03874 R. J. Deloach, Project Manager, Seabrook Project i

Yankee Electric Atomic Co. l 1671 Worcester Road Framingham, MA 10701 L

George Tsouderos D. Hudgins D. Jones