TRANSCONTINENTAL GAS PIPE LINE COMPANY

Incident Narrative

WHILE PERFORMING ARIEL PATROLS, BUBBLES WERE SPOTTED ON A TRANSCO ROW, WHERE TRANSCO OPERATES 4 PIPELINES. IMMEDIATLEY, THE NRC WAS CONTACTED ALONG WITH THE LOUISIANA STATE POLICE. TRANSCO OPERATORS HAVE ISOLATED THE LINE. THE CURRENT STATUS OF THE INCIDENT INVESTIGATION IS IN THE PRELIMINARY STAGE. THIS REPORT WILL BE UPDATED AS MORE DATA IS RECIEVED. SUPLEMENTAL LEAK REPORT UPDATE: - ON 9/27/2012 THE LEAK WAS INVESTIGATED THE LEAK WAS LOCATED ON A PIPELINE LOCATED IN A INLET TO THE GOM. - DIVERS EXPOSED THE LINE AND REMOVED EXTERNAL COATING (MASTIC AND CONCRETE). - WE IDENTIFIED AN ISOLATED PINHOLE LEAK AT THE SIX O'CLOCK POSITION IN A GIRTH WELD, - WE THEN REMOVED COATING AND CLEANED PIPE 3' ON BOTH SIDES OF THE GIRTH WELD - THE PIPE WAS VISUALLY INSPECTED AND A UT INSPECTION OF LEAK AREA WAS ALSO PREFORMENED.THE INSPECTIONS CONFIRMED AN ISOLATED PINHOLE LEAK. - THE DIVERS INSTALLED A MECHANICAL LEAK CLAMP. - THE ARE AFFECTED WAS RECOATED AND CHECKED FOR LEAKS. - THE LINE WAS THEN RETURNED TO SERVICE ON 10-1-2012. WE DETERMINED THAT THE CAUSE OF THE LEAK WAS AN ISOLATED PINHOLE LEAK AT 6'OCLOCK POSITION, ON A GIRTH WELD DUE TO INTERNAL CORROSION. THIS CONCLUSION IS CONSISTANT WITH TGPL'S FIELD TECHNICIANS EXPERIENCE WITH PREVIOUS INCIDENTS OF THIS NATURE.