MARATHON PIPE LINE LLC

Incident Narrative

ON 07/10/2023 AT 09:30 MOUNTAIN TIME, CONTRACTORS WERE MAKING WELD REPAIRS ON LEG STRIKER PLATES WHEN THE TANK LEG CAUGHT FIRE DUE TO GASOLINE BEING TRAPPED BETWEEN THE LEG AND STRIKER PLATE. THE TANK WAS ISOLATED FROM NORMAL OPERATIONS AS IT WAS IDLE FOR AN API 653 INSPECTION/MAINTENANCE. THE FIRE WAS IMMEDIATELY EXTINGUISHED, AND WORK STOPPED. OPERATIONS WAS NOTIFIED AT 10:30 MOUNTAIN TIME AND STAKEHOLDERS DETERMINED THAT AN NRC NOTIFICATION SHOULD BE MADE. SUPPLEMENTAL UPDATE 08/22/2023 THE TANK CLEANING PROCEDURE SPECIFIES THE MOVEMENT OF THE TANK LEG, BY EITHER LIFTING OR TAPPING WITH A HAMMER, AGAINST THE STRIKER PLATE AS A MEANS TO BREAK THE SEAL CREATED BY COHESIVE FORCES OF A LIQUID THAT COULD BE TRAPPED INSIDE THE TANK LEG. AS A RESULT OF THE INVESTIGATION, IT WAS DETERMINED THAT THERE WAS A PROCESS ERROR IN WHICH SOME DISCRETION IN THE DEGREE OF MOVEMENT OF THE LEG AGAINST THE STRIKER PLATE ALLOWED FOR THE LIQUID TO REMAIN TRAPPED INSIDE THE LEG. IN ORDER TO REMEDY THIS ISSUE, THE TANK CLEANING PROCEDURE WILL BE UPDATED TO REQUIRE COLD DRILLING FOR ALL TANK LEGS THAT DO NOT HAVE DRAINAGE HOLES. OPERATIONAL PERSONNEL DID NOT BELIEVE THAT EMPLOYEE PERFORMANCE WAS A CONTRIBUTING FACTOR IN THIS INCIDENT, BUT, RATHER, THAT THE FAILURE WAS THE RESULT OF GAPS IN THE PROCEDURE. MPL AGREES THAT ITS PROCEDURE SHOULD BE CLARIFIED. ADDITIONALLY, IT IS EDUCATING OPERATIONAL PERSONNEL REGARDING THE REQUIREMENTS OF POST-ACCIDENT DRUG AND ALCOHOL TESTING. SUPPLEMENTAL 03/08/2023 - UPDATED D7 AND D7A TO CORRECT ERRONEOUSLY REPORTED HCA DETERMINATIONS, THE ACCIDENT OCCURRED IN AN OPA AND HPA.