PNO-II-85-102, crack-like Indications Discovered on Surface of Cross Assembly Which Ties 24-inch Discharge Piping of Recirculation Pump to Jet Pump 16-inch Ring Supply Header. Util & Nutech Performing Evaluation

PNO-II-85-102:crack-like Indications Discovered on Surface of Cross Assembly Which Ties 24-inch Discharge Piping of Recirculation Pump to Jet Pump 16-inch Ring Supply Header. Util & Nutech Performing Evaluation

ML20134A861
Person / Time
Site:	Grand Gulf
Issue date:	10/31/1985
From:	Carroll R, Crowley B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
References
PNO-II-85-102, NUDOCS 8511110066
Download: ML20134A861 (2)

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October 31, 1985 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PN0-II-85-102 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verifi-cation or evaluation, and is basically all that is known by the Region II staff on this date.

FACILITY: Mississippi Power & Light Company Licensee Emergency Classification:

Grand Gulf Unit 1 Notification of Unusual Event Docket No. 50-416 Alert Port Gibson, Mississippi Site Area Emergency General Emergency X Not Applicable

SUBJECT:

CRACK INDICATIONS ON SURFACE OF RECIRCULATION PIPING Mississippi Power & Light (MP&L) has detected numerous crack-like indications on the surface of the cross assembly which ties the 24-inch discharge piping of one recirculation pump to the piping's associated jet pump 16-inch ring supply header.

The indications were disclosed by dye penetrant testing after MP&L's contractor, Nutech Engineering Inc., had performed induction heat stress improvement work on selected recirculation piping welds. These indications are circumferentially located within a seven-inch band below the cross-to-cap weld area and within a six-inch band above the cross-to-discharge piping weld area. The base metal is more than two inches thick at these locations.

The indications are about three-quarters of an inch long and a quarter-inch deep, with the exception of one indication in the lower six-inch band which is about three and a half inches long. MP&L believes they are related to the induction heat stress improvenent process. Grano Gulf Unit I has been shut down for scheduled maintenance since October 13.

Region II is monitoring MP&L and Nutech's continuing evaluation, and is keeping the Offices of Nuclear Reactor Regulation and Inspection and Enforcement advised.

MP&L is prepared to respond to media inquiries.

The State of Mississippi has been infonned.

This information is current as of 2:30 p.m. (EST) today.

Contact:

R. Carroll, 242-5543 B. R. C rowl ey, 242-5579 0

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