BLUEWATER GAS STORAGE, LLC

Incident Narrative

RE: OMO RD COMPRESSOR STATION INCIDENT NRC INCIDENT REPORT #1413461 & FOLLOW UP #1413594 ON OCTOBER 5, 2024 AT APPROXIMATELY 3:09 AM, EMERGENCY SHUTDOWN (ESD) VENT VALVES (BDV 9010) AND (BDV 9011) OPENED BECAUSE OF A LOSS OF POWER GAS PRESSURE USED TO HOLD THE ESD VALVES CLOSED. PIPELINE ISOLATION (SDV-9001) WAS ALSO OPEN, RESULTING IN A GAS RELEASE OF ~5.2 MMSCF TO ATMOSPHERE. THE LOSS OF POWER GAS WAS CAUSED BY OF A COMBINATION OF AN ISOLATION OF THE POWER GAS HEADER AND A LEAKING REGULATOR IN THE POWER GAS SYSTEM. ON OCTOBER 3, 2024, AT 10:56 A.M., THE FUEL GAS SUPPLY VALVE (SDV 9008) TRIPPED / CLOSED DUE TO HIGH PRESSURE (>475 PSIG). THE HIGH PRESSURE WAS CAUSED BY DAYTIME HEATING AND THERMAL EXPANSION OF THE GAS IN THE FUEL GAS SYSTEM. THE OMO ROAD COMPRESSOR STATION WAS SHUTDOWN AT THE TIME, MINIMIZING FUEL GAS USE AND CAUSING FUEL GAS HEADER PRESSURE TO FLUCTUATE WITH AMBIENT TEMPERATURE. IN ADDITION TO ITS PRIMARY FUNCTION TO SUPPLY FUEL TO THE NATURAL GAS FIRED ENGINES USED TO DRIVE THE GAS COMPRESSORS AT THE STATION, THE FUEL GAS SYSTEM ALSO PROVIDES POWER GAS TO THE POWER GAS HEADER. TYPICALLY, POWER GAS PRESSURE IS HIGH ENOUGH THAT THE GAS PRESSURE OVERCOMES THE SPRING TENSION USED TO OPEN THE BLOWDOWN VALVES IN THE EVENT OF AN ESD. FOLLOWING THE OVERPRESSURE CONDITION, SDV 9008 WAS NOT REOPENED BECAUSE THE COMPRESSOR STATION WAS IDLE AND THE NEED FOR FUEL GAS WAS MINIMAL. WITH SDV 9008 CLOSED AND THE POWER GAS HEADER ISOLATED, A LEAKING REGULATOR ON BDV 9011 EVENTUALLY BLED OFF ENOUGH PRESSURE FROM THE POWER GAS HEADER TO ALLOW BDV 9010 AND BDV 9011 TO FAIL OPEN AS DESIGNED. THE LEAKING REGULATOR WAS IDENTIFIED FOLLOWING THE RELEASE ON OCTOBER 5, 2024 AND REPAIRED ON OCTOBER 17, 2024. CORRECTIVE ACTION: BLUEWATER WILL IMPLEMENT CORRECTIVE ACTIONS TO PRECLUDE REPETITION OF THE INCIDENT, MINIMIZE THE AMOUNT OF VENTED GAS, AND IMPROVE REPORTING TIMELINESS. 1. UPDATE PROCEDURES TO AVOID THE ISOLATION OF THE POWER GAS HEADER: A. OPTION 1: SDV 9008 (FUEL GAS SUPPLY) WILL BE OPEN DURING NORMAL AND STAND BY OPERATIONS B. OPTION 2: (TBD) VB-9071 CHANGED TO 'NORMALLY OPEN' TO PROVIDE AN UNINTERRUPTED SUPPLY TO THE POWER GAS HEADER 2. CONTROL LOGIC AT THE SITE ALLOWED FOR THE PIPELINE VALVE (SUPPLY GAS) TO REMAIN OPEN WHEN THE VENT VALVES BDV 9010 AND BDV 9011 WERE OPEN. A. BLUEWATER HAS UPDATED LOGIC AT THE FACILITY, IF A VENT VALVE IS IN ANY POSITION OTHER THAN ""CLOSED"" THE PIPELINE VALVE FEEDING THE FACILITY (SDV 9001) WILL CLOSE. 3. SCADA ALARMS TO IMPROVE RESPONSE TIME WILL BE ADDED. A. ""VALVES OUT OF SEQUENCE"" NOTIFYING THE OPERATOR THAT THE VENT VALVE AND THE PIPELINE VALVES ARE OPEN OR IN TRAVEL. B. ""LOW PIPELINE PRESSURE"" AN ADJUSTABLE ALARM THE OPERATORS CAN SET FOR THE CURRENT OPERATING CONDITIONS ON THE PIPELINES. C. ""LOW LOW PIPELINE PRESSURE"" A NON-ADJUSTABLE ""HIGH PRIORITY"" ALARM SET AT 650 PSIG. 4. REVISE EMERGENCY PROCEDURES TO INCLUDE VOLUMETRIC THRESHOLDS FOR REPORTING NATURAL GAS RELEASES TO FEDERAL AND STATE AGENCIES CONSISTENT WITH EXISTING RULES AND REGULATIONS. 5. TRAINING: ADDITIONAL/REFRESHER TRAINING ON REPORTING REQUIREMENTS I.E. TIME TO REPORT, AND THRESHOLDS FOR REPORTING. BLUEWATER COMPLETED THE TRAINING FOR APPROPRIATE EMPLOYEES ON OCTOBER 15, 2024.