TC OIL PIPELINE OPERATIONS INC

Incident Narrative

ON 6 FEBRUARY 2019, AT 08:14 CST, AN EMPLOYEE IDENTIFIED A SMALL VOLUME OF CRUDE OIL ON THE KEYSTONE PIPELINE SYSTEM AND PLATTE PIPELINE SYSTEM RIGHT OF WAY IN ST. CHARLES COUNTY, MO. THIS RESULTED IN THE IMMEDIATE SHUTDOWN OF THE KEYSTONE PIPELINE. THE NATIONAL RESPONSE CENTER (NRC) WAS NOTIFIED AND THERE WAS NO IMPACT TO WATER. A 48-HR UPDATE TO THE NRC GENERATED REPORT 1237163. THE SOURCE OF THE LEAK WAS DETERMINED TO BE A FEATURE LOCATED UNDER A PREVIOUS COMPOSITE WRAP REPAIR. STOPPLES WERE INSTALLED UPSTREAM AND DOWNSTREAM OF THE FEATURE AND THE PIPELINE REPAIRED. THE PIPELINE WAS SUBSEQUENTLY RESTARTED ON 19 FEBRUARY 2019. THE FAILED SECTION WAS TRANSPORTED FOR MECHANICAL AND METALLURGICAL TESTING AND A ROOT CAUSE FAILURE ANALYSIS COMPLETED. 20190802 FINAL REPORT. THE COMPOSITE WRAP WAS INADEQUATELY DESIGNED FOR THE METAL LOSS FEATURE IT WAS TO PROTECT, AS THE APPLICATOR'S INTERPRETATION OF THE FEATURE AS MECHANICAL DAMAGE LED TO FEWER WRAPS THAN CORROSION GIVEN THE NAMING CONVENTION USED IN THE COMPOSITE VENDOR'S SOFTWARE. FEATURE DIRECT EXAMINATION CONCLUDED BLUNT METAL LOSS WITH NO EVIDENCE OF SHARP EDGES OR STRESS CONCENTRATORS, AND THE FEATURE ROOT CAUSE ANALYSIS DETERMINED THE ACCELERATED RATE OF CORROSION WAS PRIMARILY CAUSED BY STRAY DIRECT CURRENT INTERFERENCE AND WAS SUBSEQUENTLY REPAIRED. THE RCFA INDICATED THE PRIMARY CAUSE OF THE LEAK WAS A THROUGH-WALL CRACK THAT EXHIBITED SIGNS OF FATIGUE, INITIATED FROM LOCALIZED STRESS CONCENTRATIONS IN THE IRREGULAR PITTED SURFACE OF THE REPAIRED METAL LOSS FEATURE.