ML19320C575

Final Deficiency Rept PRD-80-26 Re Defective GE SB-12 Switches Identified in IE Circular 79-17.Switches Found to Be Installed in Switchgear Supplied by Vendor.Vendor Will Furnish New Switches to Correct Condition

ML19320C575
Person / Time
Site:	Grand Gulf
Issue date:	07/10/1980
From:	MISSISSIPPI POWER & LIGHT CO.
To:
Shared Package
ML19320C574	List: ML19320C573 ML19320C575
References
IEC-79-17, NUDOCS 8007170400
Download: ML19320C575 (1)

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. Atte. chm:nt A to AECM-80/152 Page 1 of 1 O

FINAL REPORT, PKD-80/26 I. Description of Deficiency Defective SB-12 switches identified in IE Circular 79-17 were found to be installed in switchgear supplied by the vendor.

The defect is an intermittent contact problem which will cause lack of continuity through the "a" contact of the switch that is used to energize the trip coil of the circuit breaker.

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II. Safety Implications .

The SB-12 switches are used in the' circuit breakers of the 6.9 KV switchgear units which control the reactor recirculation pumps. The safety function of the breaker is to. trip on a signal from the Reactor Protection System. The postulated failure of the SB-12 switch would prevent the energizing of the trip coil thereby preventing the breaker from fulfilling its intended safety function.

III. Corrective Action Taken The vendor will furnish new SB-12 switches to correct the condi-tion and preclude recurrence.

., l'toyoo

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