LOUISVILLE GAS & ELECTRIC CO

Incident Narrative

ON OCTOBER 20, 2021 AT APPROXIMATELY 08:25 A.M. OPERATOR WAS NOTIFIED BY LANDOWNER OF PIPELINE RUPTURE NEAR BRANDENBURG, KENTUCKY, RESULTING IN AN UNCONTROLLED NATURAL GAS RELEASE. OPERATOR ARRIVED ON SITE AT APPROXIMATELY 08:45 A.M. AND THE VALVES WERE ISOLATED BY 09:06 A.M. RUPTURE OCCURRED ON AN 8-INCH CARBON STEEL PIPELINE LOCATED IN THE DOE RUN STORAGE FIELD. THE RUPTURE DID NOT CAUSE ANY INJURIES OR SIGNIFICANT THIRD-PARTY PROPERTY DAMAGE. NO IGNITION OF GAS OCCURRED DURING THIS EVENT. A SECTION OF THE PIPELINE MEASURING 7,677 FEET, INCLUDING THE SEGMENT OF PIPING INVOLVED IN THIS INCIDENT, WAS ABANDONED. THE BULK OF THE ABANDONED PIPE HAD BEEN ISOLATED BY VALVES DURING THE INCIDENT RESPONSE. SELECTIVE SEAM INTERNAL WELD CORROSION WAS IDENTIFIED AS THE CAUSE OF THE INCIDENT. LINE PIPE METALLURGY AND PIPELINE CONSTRUCTION ALSO WERE CONTRIBUTING FACTORS IN THE RUPTURE. EARLY VINTAGE (PRE-1970S) ERW LINE PIPE IS PARTICULARLY SUSCEPTIBLE TO SELECTIVE SEAM WELD CORROSION AS A RESULT OF THE STEEL CHEMISTRY AND THE ABSENCE OF A POST WELD HEAT TREATMENT THAT FULLY NORMALIZED THE SEAM WELD OF THE LINE PIPE. INSTALLING THE SEAM WELD NEAR THE 6:00 ORIENTATION CONTRIBUTED TO THE INCIDENT AS WELL BECAUSE ANY WATER AND/OR DEPOSITS THAT ACCUMULATE IN THE PIPE WILL BE IN CONTACT WITH THE CORROSION-SUSCEPTIBLE MICROSTRUCTURE OF THE SEAM WELD.