NORTH DAKOTA PIPELINE COMPANY LLC

Incident Narrative

ON JUNE 22, 2021, AT APPROXIMATELY 1:45 PM CDT, PIPELINE MAINTENANCE WELDERS WERE PERFORMING A BUTTERING WELD PASS FOR THE INSTALLATION OF A REPAIR SLEEVE ON LINE 84 AT MP 38.49 WHEN A SMALL FIRE (APPROXIMATELY 1 CUBIC FOOT IN SIZE) OCCURRED DUE TO BURN THROUGH. THE FIRE SELF-EXTINGUISHED AFTER APPROXIMATELY FIVE MINUTES. APPROXIMATELY ONE TEASPOON OF RESIDUAL OIL WAS RELEASED. NO LEAKING PRODUCT WAS SEEN AFTER THE FIRE DISSIPATED. OPERATIONS WAS NOTIFIED AND THEY WERE DISPATCHED TO THE SITE. THE EDMONTON CONTROL CENTER WAS NOTIFIED OF THE EVENT. LINE 84 WAS ALREADY SHUT DOWN DUE TO SCHEDULED WORK AND WAS ISOLATED. NO INJURIES OCCURRED AS A RESULT OF THE EVENT. THE NRC WAS NOTIFIED ON JUNE 22, 2021 AT 3:45 PM CDT (#1308498). A PLIDCO SLEEVE WAS INSTALLED ON THE PIPE. A CUTOUT/REPLACEMENT AT THE BURN THROUGH SITE WAS COMPLETED ON NOVEMBER 3, 2021. A THIRD-PARTY METALLURGICAL ANALYSIS WAS CONDUCTED TO AID IN THE INVESTIGATION TO DETERMINE A ROOT CAUSE. EVIDENCE SUGGESTS THAT THE WELDING PERFORMED WAS OUTSIDE THE ACCEPTABLE RANGE LISTED ON THE WELD PROCEDURE DATA SHEET AND HIGHER THAN ALLOWABLE WELDING PARAMETERS DUE TO THE MACHINE SETTINGS BEING TOO HIGH. THERE WAS NO PRE-WELD VERIFICATION USING CALIBRATED EQUIPMENT AND NO CONTINUAL MONITORING TO ENSURE PROPER OPERATION WITHIN THE RESTRICTED WELDING PARAMETER RANGE PRIOR TO THE BURN THROUGH OCCURRING. THERE WERE NO PIPE ANOMALIES DETECTED OR INDICATIONS TO SUGGEST THE WELDING PARAMETERS OUTLINED ON THE WELD PROCEDURE DATA SHEET WERE INAPPROPRIATE OR THAT ENVIRONMENTAL FACTORS AND FLOW CHARACTERISTICS IN THE PIPELINE CONTRIBUTED TO THE BURN THROUGH. CORRECTIVE AND PREVENTATIVE ACTIONS TO BE IMPLEMENTED INCLUDE DEVELOPMENT OF IN-SERVICE WELD PROCEDURE DATA SHEETS TO ENHANCE SAFETY AND USABILITY TO FURTHER REDUCE THE RISK OF BURN THROUGH DURING WELDING ON THIN-WALLED PIPE (LESS THAN OR EQUAL TO 0.250 INCH), UPDATING REQUIREMENTS FOR WELD PARAMETER MONITORING TO BETTER REFLECT THE TIGHTER LEVEL OF CONTROL REQUIRED FOR WELD PARAMETER MONITORING ON THIN-WALLED PIPE, PRESENT OVERALL LESSONS LEARNED AS A RESULT OF THE INVESTIGATION AND AN AWARENESS PRESENTATION OUTLINING THE RISKS ASSOCIATED WITH THIN-WALL WELDING AND EMPHASIZE THE IMPORTANCE OF WELD PARAMETER CONTROL AS A MATTER OF SAFETY AND BURN THROUGH PREVENTION. *THE ACTUAL VOLUME RELEASED AT MP 38.49 WAS 0.0013 GALLONS. THE PHMSA PORTAL DOES NOT RECOGNIZE VOLUMES LESS THAN 0.1 BARRELS THEREFORE THAT IS THE VOLUME ENTERED IN PART A.