GOLDEN TRIANGLE STORAGE, INC.

Incident Narrative

ON 9-13-2021 THE EVENT STARTED WHEN PREPARING FOR TROPICAL STORM NICHOLAS. AS PART OF THE PREPAREDNESS OPERATIONS, THE FACILITY WAS SWITCHED TO GENERATOR POWER TO ENSURE THE SAFETY OF OPERATIONS SHOULD THERE BE A LOSS OF COMMERCIAL POWER. DURING THE POWER TRANSFER, THE AUTO TRANSFER SWITCH DID NOT CHANGE OVER QUICKLY ENOUGH TO PREVENT THE ESD SYSTEM FROM SENSING A POWER LOSS. AS A RESULT, THE ESD SYSTEM ACTUATED AND BLEW DOWN THE COMPRESSOR BUILDING PIPING. WITH GENERATOR POWER ONLINE, THE OPERATOR RESET THE ESD AND STARTED COMPRESSOR C. HOWEVER, AN AUTOMATED BLOWDOWN VALVE REQUIRED FOR THE ESD ON COMPRESSOR C FAILED TO CLOSE TO 100% DESPITE THE VALVE CLOSE LIMIT INDICATOR SHOWED CLOSED. THE ESD ACTIVATED DETECTION SYSTEM AT THE BLOWDOWN SILENCER DID NOT ACTIVATE DUE TO THE LOW FLOW RATE OF GAS AT THE BLOWDOWN SILENCER. THE OPERATOR ON SHIFT NOTICED GAS VAPORS COMING OUT OF THE BLOWDOWN SILENCER AT 8:30 PM. THE OPERATOR CALLED THE I&E TECH. AT 8:30 PM 9/13/21 TO NOTIFY HIM OF THE VAPORS COMING OUT OF THE BLOWDOWN SILENCER. THE I&E TECH WAS ALREADY ON HIS WAY TO WORK TO STAY THE NIGHT FOR THE STORM. WHEN THE I&E TECH ARRIVED, THE LEAK APPEARED TO BE SMALL, AND WAS TOO DANGEROUS WITH WINDS, RAIN, AND LIGHTING TO INVESTIGATE THE LEAK. ONCE THE STORM PASSED AT 8:30 AM THE I&E TECH DISCOVERED THE PARTIALLY OPEN BLOWDOWN VALVE AND COMPLETELY CLOSED IT. THIS FAILURE TO HAVE 100% CLOSURE RESULTED IN NATURAL GAS ESCAPING THROUGH THE VENT OUT OF THE BLOWDOWN SILENCER. DURING A REVIEW OF THE SYSTEM BALANCE ANALYSIS EQUATIONS FOUND THAT ENOUGH GAS MAY HAD BEEN RELEASED TO THE ATMOSPHERE TO TRIGGER REPORTING. FURTHER INVESTIGATION INDICATED THAT A REPORT OF THE RELEASE REQUIRED. THE REPORT WAS MADE AT 2:15 CST. TO THE NRC.