SHELL PIPELINE CO., L.P.

Incident Narrative

AT APPROXIMATELY 12:20 PM ON 2/26/2020 PRODUCT WAS OBSERVED ON TANK 79'S INTERNAL FLOATING ROOF. ALL PRODUCT IS CONTAINED WITHIN THE TANK WITH NO IMPACT TO SOIL OR WATER. NO INJURIES WERE REPORTED. AGENCY NOTIFICATIONS HAVE BEEN MADE. THE TANK WAS ISOLATED UNTIL PERSONNEL FROM OPERATIONS, ENGINEERING, HSSE, AND THE INTEGRITY GROUP COULD CONVENE TO DEVELOP A GO-FORWARD PLAN. RELEASE IS BELOW PHMSA REPORTABLE AMOUNT BUT REPAIR COST EXCEEDS 25000$ WHICH IS THE REASON FOR REPORTING. UPDATE: A ROOT CAUSE ANALYSIS (RCA) WAS CONDUCTED TO IDENTIFY THE CAUSE OF THE FAILURE OF THE INTERNAL FLOATING ROOF. DATA RELATED TO POTENTIAL CAUSES WERE INVESTIGATED AND NO DEFINITIVE CAUSE RELATED TO EITHER THE ROOF FAILURE OR POTENTIAL PATHS THAT COULD HAVE LED TO THE PRODUCT GETTING ON THE ROOF WAS IDENTIFIED. DATA THAT WAS EXAMINED INCLUDED, FOR EXAMPLE, ENVIRONMENTAL THREATS, FLOATING ROOF INTEGRITY ISSUES, TANK OPERATIONAL UPSETS, CHANGES IN PRODUCT CHARACTERISTICS, TANK FOUNDATION SETTLEMENT, TANK SHELL ANOMALIES AND FLOATING ROOF AND SEAL OBSTRUCTIONS. THE POTENTIAL CAUSE COULD HAVE BEEN A CONSTRICTION POINT BETWEEN THE INTERNAL TANK SHELL AND FLOATING ROOF IN THE UPPER REGION OF THE TANK. RECOMMENDATIONS WERE DEVELOPED TO PREVENT SIMILAR INCIDENT IN FUTURE. SUCH AS MONTHLY INSPECTION AND MITIGATION PLAN TO RETROFIT THESE TYPES OF PAN-ONLY STYLE FLOATING ROOFS WITH BULKHEADS TO ADD STRUCTURAL STABILITY TO THE ROOF AND COMPARTMENTALIZE THE INTERNAL ROOF TO INCREASE ITS ABILITY FOR FLOATATION AND BUOYANCY ALONG WITH THE APPROPRIATE INSTALLATION SCHEDULE SUCH AS DURING THE NEXT API 653 OUT-OF-SERVICE INSPECTION.