TENNESSEE GAS PIPELINE COMPANY — Gas transmission and gathering — incident on 2020-06-04

Gas transmission and gathering incident in MOREHEAD, ROWAN County, KY. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 11029.8 NATURAL GAS released, $450 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20200069.

Operator ID: 19160.

Reported incident date: 6/4/2020 14:27.

Cause detail: EQUIPMENT NOT INSTALLED PROPERLY

Cause detail: AT 2:20 PM TENNESSEE GAS PIPELINE COMPANY, L.L.C. (TGP) CONTROL ROOM RECEIVED AN ALARM OF AN EMERGENCY SHUTDOWN (ESD) AT STATION 110 IN MOREHEAD, KENTUCKY. AT 2:32 PM, AN OPERATOR ARRIVED ON SITE TO BEGIN ASSESSING THE ESD SYSTEM. THE RELEASED WAS STOPPED AT 2:45 PM AND AT 4:30 PM, WHILE ATTEMPTING TO RESET THE ESD SYSTEM, IT WAS DISCOVERED THAT VALVE 1D7, WHICH IS ON A SUCTION LINE COMING OFF OF LINE 100-7, DID NOT CLOSE AS DESIGNED DURING THE ESD. BECAUSE THE VALVE DID NOT CLOSE DURING THE ESD, GAS FROM THE MAINLINE WAS MAKING ITS WAY THROUGH THE SUCTION SIDE OF THE STATION AND OUT OF THE STATION SILENCER, VENTING TO ATMOSPHERE. AN EMERGENCY RESPONSE CALL WAS HELD AT 5:00 PM TO DISCUSS THE EVENT. BECAUSE THE 1D7 VALVE DID NOT CLOSE IT WAS FORECASTED THAT THE GAS LOSS QUANTITY WOULD EXCEED 3,000 MCF. AS A RESULT OF THIS FORECAST THE EVENT WAS REPORTED TO THE NRC. THE INITIAL ASSESSMENT DISCOVERED THAT A LIGHTNING EVENT CAUSED THE STATION TO ESD. AFTER FURTHER INVESTIGATION, IT WAS FOUND THAT THE VALVE OPERATOR ON VALVE 1D7 HAD RECENTLY BEEN REPLACED WITHOUT A MANAGEMENT-OF-CHANGE (MOC). THE VALVE OPERATOR HAD A DEFAULT CONFIGURATION FOR "PRESSURE-UP" ACTIVATION ON AN ESD SYSTEM; HOWEVER, THE ESD SYSTEM AT STATION 110 FUNCTIONS AS A "PRESSURE-DOWN" ESD SYSTEM. INSTALLATION OF THE VALVE OPERATOR WITHOUT AWARENESS OF ITS DEFAULT DESIGN CONFIGURATION, CAUSED VALVE 1D7 NOT TO CLOSE DURING THE ESD AT THE STATION. AS A CORRECTIVE ACTION, TGP REVIEWED ITS MOC PROCEDURE WITH OPERATORS AT STATION 110. OPERATORS WERE RETRAINED TO RECOGNIZE THAT A MOC IS NEEDED FOR MAKING CHANGES TO THE NORMAL DESIGN CONDITIONS OR DESIGN PARAMETERS OF PIPELINE OPERATIONS.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: INCORRECT OPERATION — INCORRECT INSTALLATION.

PHMSA indexed costs: $22,819 reported total cost, $22,714.479 in 1984 dollars, $30,842.418 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.