ENABLE GAS TRANSMISSION, LLC

Incident Narrative

ON 5/2/2019 AT 22:39 ENABLE GAS TRANSMISSION LINE BT-1 EXPERIENCED A FAILURE NEAR HOT SPRINGS VILLAGE IN GARLAND COUNTY, ARKANSAS. THE FAILED SECTION OF BT-1 WAS SENT TO STRESS ENGINEERING SERVICES (SES) FOR METALLURGICAL ANALYSES. AS OF THE DUE DATE FOR THIS REPORT, THE LINE IS CURRENTLY OUT OF SERVICE AND THE RESULTS OF THE ANALYSIS HAVE NOT BEEN RECEIVED. PRELIMINARY FINDINGS FOR THE FAILURE ARE NEAR NEUTRAL STRESS CORROSION CRACKING ACTING WITHIN AREA OF EXTERNAL CORROSION. THE NRC WAS NOTIFIED ON 5/3/2019 AT 02:03 (NRC#1244490). A 48 HOUR FOLLOW UP CALL WAS PROVIDED TO THE NRC ON 5/4/2019 AT 14:54 (NRC# 1244649). THE FAILURE INVESTIGATION IS ON-GOING. ------UPDATE------ BASED ON EXAMINATIONS AND ANALYSIS BY STRESS ENGINEERING, IT WAS DETERMINED THE PIPE FAILED AS A RESULT OF NEAR-NEUTRAL PH STRESS CORROSION CRACKING (SCC) IN CONCERT WITH GENERAL EXTERNAL CORROSION THAT REDUCED THE WALL THICKNESS NEAR THE 6 O'CLOCK ORIENTATION OF THE PIPE. THE PIPELINE CONTINUES TO BE OUT OF SERVICE UNTIL ALL OF THE 30"" IS HYDROTESTED. ------UPDATE------ THE LINE HAS BEEN FULLY HYDROTESTED AND WAS PLACED BACK INTO SERVICE ON FEBRUARY 2, 2020. 09/25/2019 SUPPLEMENTAL A.10 GAS LOSS VOLUME UPDATED. D.7 UPDATED CONSTRUCTION COSTS D.7.F GAS LOSS TOTAL UPDATED G.1 UPDATED TO DETERMINED BY METALLURGICAL ANALYSIS H. NARRATIVE UPDATED 2/3/2020 SUPPLEMENTAL A.15.B UPDATED TO 2/2/2020 AND 09:30 C.3.D UPDATED TO API-5L C.3.E UPDATED TO SUBMERGED ARC WELDING D.7 COSTS UPDATED E.5.C ENTERED 88,338 H. NARRATIVE UPDATED