ENABLE OKLAHOMA INTRASTATE TRANSMISSION, LLC

Incident Narrative

ON OCTOBER 21ST, 2022, AT APPROXIMATELY 19:00 HOURS, TECH WAS DISPATCHED TO BENNINGTON CS UNIT 447 TO TROUBLESHOOT UNIT 447 GOING DOWN. TECH CORRECTED THE ISSUE, PUT IT BACK ONLINE AND DEPARTED. UNIT 447 WENT BACK DOWN ON OIL TEMPERATURE ON THE SAME DATE AT APPROXIMATELY 20:30 HOURS. AT APPROXIMATELY 20:35 HOURS, TECH ADVISED GAS CONTROL TO START UNIT 442 REMOTELY. TECH THEN WENT BACK TO STATION TO RESET THE OIL COOLER TEMPERATURE SHUTDOWN ON UNIT 447. DURING THIS TIME, UNIT 442 FAILED TO START DUE TO NOT BEING PRESSURIZED. AT APPROXIMATELY 21:05, TECH THEN STARTED UNIT 447 AND PUT BACK ONLINE AND ADVISED GAS CONTROL THAT UNIT 442 WAS UNAVAILABLE DUE TO THE LOAD VALVE FAILURE. ON MONDAY, OCTOBER 24TH, 2022, AT APPROXIMATELY 07:00 HOURS, TECH ARRIVED AT THE STATION AND WAS REVIEWING ALARMS THAT OCCURRED OVER THE WEEKEND. HE NOTICED THAT THE LOAD VALVE FAILURE ALARM ON UNIT 442 WAS STILL ACTIVE. TECH WENT OUT TO UNIT 442 TO PHYSICALLY INSPECT WHY THE ALARM WAS STILL ACTIVE. TECH DISCOVERED THAT UNIT 442'S LOAD VALVE WAS PARTIALLY OPEN AND VENTING GAS. AT 08:25 HOURS, TECH MANUALLY CLOSED THE LOAD VALVE ON UNIT 442 TO PREVENT IT FROM VENTING AND NOTIFIED HIS SUPERVISOR OF THE INCIDENT AT APPROXIMATELY 08:30 HOURS. SUPERVISOR THEN INITIATED AN INVESTIGATION OF THE INCIDENT TO TRY AND DETERMINE HOW LONG THE VALVE HAD VENTED GAS AND WHAT CAUSED THE INCIDENT. A BALANCE SEGMENT WAS DONE ON BENNINGTON COMPRESSOR STATION TO DETERMINE THE VOLUME OF GAS VENTED. IT WAS DETERMINED THAT THE VALVE HAD VENTED GAS FROM OCTOBER 21ST, 2022, AT 21:02 HOURS TO OCTOBER 24TH, 2022, AT 08:25 HOURS (APPROXIMATELY 59 HOURS AND 23 MINUTES). ON OCTOBER 24TH AT APPROXIMATELY 14:10 HOURS, SUPERVISOR NOTIFIED DOT COMPLIANCE PERSONNEL. AT THIS POINT, IT WAS DETERMINED TO BE A REPORTABLE INCIDENT. INCIDENT WAS REPORTED TO NRC ON OCTOBER 24TH, 2022, AT 14:20. ON OCTOBER 25TH, 2022, AT APPROXIMATELY 13:00 HOURS, PLC PROGRAMMER REVIEWED THE PROGRAMMING ON UNIT 442 AND DETERMINED THERE WAS NOT A LOGIC IN THE PLC THAT WOULD PREVENT THIS FROM HAPPENING. ON OCTOBER 26TH, 2022, AT APPROXIMATELY 10:00 HOURS, PLC PROGRAMMER AND STATION I&E TECH, MADE THE PLC LOGIC CHANGES THAT WOULD PREVENT THIS FROM HAPPENING AGAIN. WE NOW HAVE A TIMED LOCKOUT ON THE UNIT THAT IF IT DOES NOT START IN A CERTAIN PROGRAMMED TIME, THE VALVE WILL AUTOMATICALLY CLOSE THE VENT VALVE AND GIVE AN ALARM OF THE LOCKOUT. THE UNIT WAS LEFT LOCKED AND TAGGED OUT UNTIL SUCH PLC PROGRAMMING COULD BE TESTED AND VERIFIED TO BE ACCURATE. ON DECEMBER 1ST, 2022, AT APPROXIMATELY 08:00 HOURS, LOGIC WAS TESTED ON THE PLC FOR UNIT 442, AND PROVEN TO BE EFFECTIVE. THIS CHANGE WILL PREVENT FURTHER INCIDENTS FROM OCCURRING. A SPECIFIC CAUSE OF THE LOAD VALVE FAILURE COULD NOT BE PINPOINTED THEREFORE, A NEW LOAD VALVE (NEW VALVE AND ACTUATOR) WAS ORDERED AND IS WAITING TO BE INSTALLED. UNIT 442 IS LOCKED AND TAGGED OUT OF SERVICE UNTIL A STATION OUTAGE CAN BE SCHEDULED TO REPLACE THE LOAD VALVE ON UNIT 442. NOTE: AS DIRECTED BY AID/RODRIGUEZ, THE ""EARLIEST TIME A REPORTING CRITERIA WAS MET"" WAS CHANGED ON 4/26/2023. THE ORIGINAL DATE AND TIME, 10/24/2022 14:20, WAS CHANGED TO 10/21/2022 21:02 AS DIRECTED TO DO PER AID.