SOUTHERN STAR CENTRAL GAS PIPELINE, INC

Incident Narrative

ON JUNE 15, 2018, AT 7:37 AM LOCAL TIME SOUTHERN STAR CENTRAL GAS PIPELINE, INC. (SSCGP) INCURRED A RUPTURE AND SUBSEQUENT FIRE ON ITS 26 INCH LINE R PIPELINE SEGMENT LOCATED IN HARVEY COUNTY, KANSAS WITHIN A CLASS 1, NON-HCA AREA. THE INITIAL RUPTURE AND FIRE WAS WITNESSED BY A SSCGP EMPLOYEE ON HIS WAY TO WORK AND HE IMMEDIATELY PROCEEDED TO THE RUPTURE SITE ARRIVING AT 7:40 AM LOCAL TIME. THE EMPLOYEE NOTIFIED HEADQUARTERS ON HIS WAY TO THE SITE. SSCGP SCADA CONTROLLER IMMEDIATELY NOTICED A PRESSURE DROP ON LINE R AND SSCGP CALLED A SIGNIFICANT EVENT. LOCAL EMERGENCY RESPONDERS WERE ON SITE BY 8:12 AM. SSCGP CALLED NRC AT 7:57 AM. A SEPARATE CALL WAS MADE TO PHMSA AT 8:08 AM. MAINLINE REMOTE CONTROLLED VALVES WERE CLOSED AT 7:39 AM AND VALVES AT HESSTON STATION WERE MANUALLY CLOSED AT 7:42 AM. PARTRIDGE RCV WAS CLOSED AT 9:12 AM AND A 20"" GATE VALVE WAS MANUALLY CLOSED AT 9:15 AM, THE RUPTURE SITE WAS ISOLATED. THERE WERE NO INJURIES, FATALITIES, OR DAMAGE TO STRUCTURES, AND THE LINE SEGMENT WAS SAFETY ISOLATED, GAS FLOW STOPPED AND FIRE EXTINGUISHED BY 10:21 AM. PHMSA INVESTIGATORS EXAMINED THE SITE BEFORE ANYTHING WAS DISTURBED. AFTER BEING GIVEN PERMISSION, THE DAMAGED SECTION OF PIPE WAS SHIPPED TO G2MT LABORATORIES IN HOUSTON, TEXAS FOR METALLURGICAL EXAMINATION. SSCGP THEN MADE ARRANGEMENTS TO REPAIR THE DAMAGE AND PLACED THE AFFECTED SECTION OF LINE R BACK IN SERVICE ON 6/19/2018 AT 9:10 PM LOCAL TIME UNDER A VOLUNTARY 20% PRESSURE REDUCTION. 189 FEET OF 26"", 0.406"" WALL, X70 PIPE WAS INSTALLED TO MAKE THE PERMANENT REPAIR. THE REPLACEMENT PIPE WAS STRENGTH TESTED ON SITE. G2MT SUBMITTED THE RESULTS OF THE METALLURGICAL FAILURE EXAMINATION TO SSCGP ON 9/18/2018. KEIFNER AND ASSOCIATES PERFORMED THE ROOT CAUSE FAILURE ANALYSIS (RCFA) AND SUBMITTED THE DRAFT RESULTS TO SSCGP ON 10/23/2018. THE RCFA DETERMINED THE CAUSE OF THE RUPTURE WAS NEAR-NEUTRAL PH STRESS CORROSION CRACKING. PART G HAS BEEN REVISED TO REFLECT THE FINDINGS OF THE RCFA.