TENNESSEE GAS PIPELINE COMPANY

Incident Narrative

THE STATION WAS IN MANNED OPERATION AS INVESTIGATION CONTINUED FROM AN ESD EVENT ON JUNE 29, 2019. (REFERENCE DOT REPORT #2019087) INCLEMENT WEATHER INCLUDING LIGHTNING ACTIVITY IN THE AREA CAUSED A MOMENTARY LOSS OF COMMERCIAL POWER. A COMPRESSOR STATION EMERGENCY SHUTDOWN (ESD) WAS INITIATED. THE INTERLOCKING COMPRESSOR STATION ESD FUNCTIONED AS DESIGNED RESULTING IN A PHMSA REPORTABLE GAS LOSS OF 3,506 MCF. OPERATIONS PERSONNEL WERE ON SITE DURING THE EVENT AND CONFIRMED A LOUD POP DUE TO LIGHTNING ACTIVITY. INVESTIGATION RESOURCES INCLUDING DIVISION CONTROLS SUPPORT, HOUSTON AUTOMATION AND OPERATIONS CONFIRMED LOCAL INCLEMENT WEATHER CAUSED THE LOSS OF COMMERCIAL POWER, AND THE STATION UPS SYSTEM DID NOT HOLD THE REQUIRED COMPRESSOR STATION VOLTAGE (120 VDC) IN THE INTERIM WHILE THE EMERGENCY GENERATOR WAS RAMPING UP TO COME ON-LINE. THIS INTERIM LACK OF VOLTAGE TRIGGERED THE COMPRESSOR STATION ESD. INVESTIGATION OF THIS EVENT AND INVESTIGATION AND REPAIRS CONCERNING THE JUNE 29, 2019 INCIDENT CONTINUED WITH THE STATION HELD OFF LINE BY OPERATIONS TO ALLOW CERTAIN TASKS TO OCCUR UNTIL JULY 10, 2019 AT 11:00-HOURS WHEN THE STATION RESUMED MANNED OPERATION. ON-SITE PERSONNEL WERE UNABLE TO LOCATE ANY DIRECT LIGHTNING STRIKE TO THE FACILITIES. NO DAMAGE BY THIS LIGHTNING EVENT AND INCLEMENT WEATHER WAS IDENTIFIED. THE STATION REMAINED IN MANNED OPERATION UNTIL OCTOBER 3, 2019, AT APPROXIMATELY 18:00-HOURS WHEN ALL REPAIRS FOR THE JUNE 29, 2019 INCIDENT WERE COMPLETED AND THE STATION RETURNED TO AUTOMATED OPERATION. NRC 48-HOUR UPDATE IS REPORT #1251213.