ML19323J247

Deficiency Rept (PRD-80/26) Re GE Type SB-12 Switches. Questions Rationale That Safety Function of Breaker Was to Trip on Signal from Reactor Protection sys.Re-evaluation Will Be Conducted & Final Rept Filed by 800710

ML19323J247
Person / Time
Site:	Grand Gulf
Issue date:	06/12/1980
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:
References
AECM-80-128, IEC-79-17, NUDOCS 8006190577
Download: ML19323J247 (2)

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MISSISSIPPI POWER & LIGHT COMPANY /

Helping Build Mississippi C" "

P. O. S O X 16 4 0, J A C K S ON MIS SIS SIP PI 3 9 2 05 June 12, 1980 PmCDUCf f CN DEPa stu tNf Office of Inspection & Enforcement U.S. Nuclear Regulatcry Cccmission Region II 101 Marietta St., N.W., Suite 3100 Atlanta, Georgia 30303 Attention: Mr. J. P. C'Reilly, Director

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/26, Status Report, GE Type SB-12 Switches (IE Circular No. 79-17)

AECM-60/12S On May 12, 1980, Mississippi Pcwer and Light CO&L) Ccepany notified Mr. M. Hunt of your office of a Potantially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns GE Type SE-12 suitches.

The investigation of this issue was initiated by our analysis of the applicability to GGNS cf NRC IE Circular 79-17, dealing with defective SB-12 switches. We have determined that SB-12 switches are employed at GGNS. These switches are used in safety related circuit breakers associated with the recirculation pump motors.

In a telephone conversation with Mr. F. Cantrell and Mr. K. Walters of your of fice on June 11, 1980, we presented cur finding that the defective SB-12 switches, as e= ployed at GGNS, did not represent a safety problem as defined in 10 CFR 50.55(e) . Cur rationale was that the safety function of the breaker w : to trip on a signal from the Reactor Protection System and that the postulated failure of the SB-12 switch would not prevent the energizing of the trip coil.

r Additienal information received this date and further investigation on this subject have given us reason to question the above stated racionale.

We intend to re-evaluate this issue and the related safety implications and 8c/'/

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MISSISSIPPI POWER & LIGHT COMPANY Office'of Inapection 5 Enforcement AEC4-80/128 U.S. Nuclear Regulatory Commission Page.2 file a final report with your office by July 10, 1980. In a telephone conversation this date, Mr. Cantrell was advised by Mr. W. Edge and Mr. G..Cesare of MP&L of our decision to re-evaluate this matter.

Yours truly, M

p J. P. McGaughy, Jr.

Assistant Vice President Nuclear Production j JGC/JDR:Im cc: Mr. N. L. Stampley Mr. T. B. McGehee Mr. T. B. Conner.

Mr. Victor Stello, Jr., Director 4 THIS COPY FOR Division of Inspection & Enforcement U.S. Nuclear Regulatory Co= mission Washington, D.C. 20555 i

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