FLINT HILLS RESOURCES, LC

Incident Narrative

UPDATED SECTION A, SECTION B, SECTION D AND SECTION G TO INCLUDE RESULTS OF INITIAL IMMEDIATE CAUSE ANALYSIS. AN FHR EMPLOYEE OBSERVED DISCOLORED VEGETATION ON THE ROSANKY TO NIXON SEGMENT AT APPROXIMATELY 09:23 ON MAY 4, 2021. THE EMPLOYEE WAS PERFORMING A GROUND PATROL IN RESPONSE TO A PRESSURE ANOMALY, THE SEQUENCE OF WHICH IS DESCRIBED BELOW. FHR SHUT THE LINE DOWN, INCLUDING THE ROSANKY TO NIXON SEGMENT, ON APRIL 21, 2021 AS A SCHEDULED SHUTDOWN. A LEAK ALARM WAS RECEIVED ON APRIL 22, 2021 AT WHICH POINT FHR INITIATED REVIEW AND MOBILIZED FIELD EMPLOYEES. IT WAS DETERMINED THAT THE FIRST PRESSURE LOSS OCCURRED ON APRIL 21, 2021 AT 20:38, APPROXIMATELY 2 HOURS FOLLOWING THE SCHEDULED SHUTDOWN. WHEN THE ALARM WAS RECEIVED, FHR'S LEAK DETECTION TEAM INITIATED A REVIEW OF RELEVANT DATA. APRIL 22, 2021: OPERATIONS MOBILIZED TO VERIFY STATION INTEGRITY, SELECT RIVER CROSSINGS AND ABOVE GROUND APPURTENANCES; THERE WERE NO INDICATIONS OF A RELEASE. APRIL 22, 2021: OPERATIONS INITIATED AERIAL PATROLS (TWO PASSES) OF THE LINE; THERE WERE NO INDICATIONS OF A RELEASE. APRIL 22 -24, 2021: OPERATIONS INITIATED A GROUND PATROL ALONG THE PIPELINE SEGMENTS, ALSO VERIFYING STATION INTEGRITY AND OBSERVING WATER CROSSINGS; THERE WERE NO INDICATIONS OF A RELEASE. APRIL 24, 2021: OPERATIONS INITIATED ADDITIONAL AERIAL PATROLS (TWO PASSES) FOLLOWING A RAIN EVENT; THERE WERE NO INDICATIONS OF A RELEASE. APRIL 25, 2021: FHR PERFORMED CONTROLLED PRESSURE CHECKS ON THE LINE SEGMENTS. THE PRESSURE CHECK NARROWED THE POTENTIAL RELEASE LOCATION TO THE APPROXIMATELY 20-MILE ROSANKY TO NIXON SEGMENT. APRIL 27 - 28, 2021: OPERATIONS CONTRACTED A COMPANY WITH CANINES CAPABLE OF BELOW GROUND OIL DETECTION. THE LINE WAS PATROLLED WITH THE CANINES; THERE WERE NO INDICATIONS OF A RELEASE. APRIL 29 - 30, 2021: NITROGEN AND TRACER GAS WERE PROCURED AND MOBILIZED, AND ASSET MODIFICATIONS WERE COMPLETED TO RENDER THE LINE CAPABLE OF A PURGE AND TRACER GAS STUDY. MAY 1 -2, 2021: OPERATIONS INITIATED A DRONE PATROL. THE DRONE WAS EQUIPPED WITH FORWARD LOOKING INFRARED (FLIR), AND THE PATROL ALSO INCLUDED A VISUAL INSPECTION; THERE WERE NO INDICATIONS OF A RELEASE. MAY 3 - 4, 2021: OPERATIONS COMPLETED A LINE PURGE, FILLED THE LINE WITH A NITROGEN AND TRACER GAS MIXTURE, AND DEPLOYED DETECTION EQUIPMENT TO TRAVERSE THE ROW VIA GROUND PATROL. DURING THE TRACER DETECTION WALKDOWN AND RESULTING GROUND PATROL, OPERATIONS DISCOVERED THE ABOVE REFERENCED VISUAL INDICATION OF A RELEASE ON MAY 4, 2021, CONFIRMING THE RELEASE. FHR BEGAN EXCAVATION ON THE AFTERNOON OF MAY 4, 2021. A PINHOLE WAS DISCOVERED AT THE APPROXIMATE 6 O'CLOCK POSITION ON THE PIPELINE. A CLAMP WAS INSTALLED AT APPROXIMATELY 17:30 ON MAY 4, 2021. ON MAY 5, 2021, THE SEGMENT OF PIPE WAS REMOVED AND REPLACED. THE REMOVED PIPE WAS SENT TO A THIRD PARTY FOR METALLURGICAL ANALYSIS. NOTIFICATION WAS MADE TO THE NRC AT APPROXIMATELY 10:05 ON MAY 4, 2021. BASED ON AVAILABLE INFORMATION, THE INITIAL RELEASE WAS REPORTED AS LESS THAN 600 BARRELS. SUBSEQUENT REVIEW OF AVAILABLE DATA HAS REDUCED THE ESTIMATED RELEASE VOLUME TO 60 BARRELS, PENDING THE RESULTS OF FURTHER INVESTIGATION. THE UPDATED ESTIMATE WAS REPORTED TO THE NRC ON MAY 6, 2021 AT 10:03 AS PART OF THE 48-HOUR FOLLOW UP.