TENNESSEE GAS PIPELINE COMPANY

Incident Narrative

ON JUNE 26, 2021, TENNESSEE GAS PIPELINE, (TGP) 24-INCH LINE 200-1 PIPELINE EXPERIENCED AN IN-SERVICE FAILURE RESULTING IN A PIPELINE RUPTURE WITH NO FIRE. THE EVENT OCCURRED IN VALVE SECTION 234-1 BETWEEN UPSTREAM CS 233 AND DOWNSTREAM CS 237. 19:25-HOURS, GAS CONTROL BEGAN TO NOTICE SLIGHT DROP IN PRESSURE HOWEVER THE PRESSURE BEGAN RETURNING TO NORMAL. 19:25-HOURS, (APPROXIMATE TIME) THE LINE BREAK DETECTION DEVICES BEGAN TO CLOSE UPSTREAM VALVE 234-1 AND DOWNSTREAM VALVE 235-1. 19:30-HOURS, (POST EVENT ESTIMATED TIME) BOTH UPSTREAM AND DOWNSTREAM MAIN LINE VALVES ARE CLOSED 20:00-HOURS, ONTARIO COUNTY SHERRIFF DEPARTMENT PERSONNEL CALLED TGP GAS CONTROL LOCATED IN HOUSTON, TEXAS; GAS CONTROL STAFF IMMEDIATELY BEGAN DISPATCHING OPERATIONS STAFF TO ONTARIO AND LIVINGSTON COUNTIES. 21:48-HOURS, OPERATIONS STAFF WAS ON SITE AND CONFIRMED THE PIPELINE BUCKLE; THERE WAS NO ACTIVE RELEASE OF GAS, NO EVIDENCE OF FIRE AND NO EMERGENCY RESPONDERS WERE ON SITE. THERE WAS NO PUBLIC EVACUATION. OTHER OPERATIONS STAFF PROMPTLY CONFIRMED THE UPSTREAM AND DOWNSTREAM MAIN LINE VALVES WERE CLOSED AND ALSO CLOSED THE TAP VALVE TO THE METER STATION CONNECTED TO LINE 200-1 IN VALVE SECTION 234-1. THERE WAS NO CUSTOMER IMPACT AS SAID METER STATION IS ALSO CONNECTED TO LINE 200-2. 22:05-HOURS, OPERATIONS STAFF CONDUCTED AN EMERGENCY RESPONSE LINE CALL AS REQUIRED BY PROCEDURE OM-159. 22:23-HOURS, TGP PROVIDED TELEPHONIC NOTIFICATION TO THE NRC OF THE EVENT WITH AN ESTIMATE OF 11,000 MCF OF GAS UNINTENTIONALLY RELEASED TO ATMOSPHERE. THE NRC REPORT NUMBER IS 1308933. 22:32-HOURS, TGP IMMEDIATELY CALLED THE PHMSA ACCIDENT INVESTIGATION DIVISION (AID) FOLLOWING THE TELEPHONIC NOTICE TO THE NRC. ON JUNE 28, 2021, TELEPHONIC NOTIFICATION WAS PROVIDED TO THE NRC FOR THE REQUIRED 48-HOUR UPDATE. THE NRC REPORT NUMBER IS 1309098. ON JUNE 28, 2021, THE FAILURE BASED ON FIELD VISUAL OBSERVATION WAS PRELIMINARILY CLASSIFIED AS A BUCKLE OR WRINKLE. SUBSEQUENT TO THE INITIAL FIELD OBSERVATIONS, A THIRD PARTY ILI VENDOR REVIEWED AND REANALYZED PRIOR IN-LINE INSPECTION (ILI) DATA FOR THE APPLICABLE SEGMENT OF PIPELINE AND IDENTIFIED THIS AS A LOCALIZED EVENT AND CLASSIFIED THE FEATURE AS A BUCKLE. THIS INFORMATION WAS SHARED WITH PHMSA SOUTHERN REGION DURING A MEETING HELD ON 7/14/2021 JULY 14, 2021. AFTER THE JUNE 28, 2021 48 HOUR NRC UPDATE REPORT 1309098, IT WAS DETERMINED THE CORRECT UNINTENTIONAL GAS RELEASE VOLUME WAS 9,162 MCF. ON JULY 9, 2021, TGP RECEIVED CORRECTIVE ACTION ORDER (CAO) CPF NO. 2-2021-010-CAO FROM PHMSA. TGP INITIATED ACTIONS TO ADDRESS THE CAO. HOWEVER, IN PARALLEL WAS MEETING WITH PHMSA TO AMEND THE CAO WHICH WAS RECEIVED ON JULY 23, 2021. ON JULY 16, 2021, THE TGP PIPELINE REPAIR WAS COMPLETED BY PIPE REPLACEMENT AND COVERED. PER THE CAO, AN INDEPENDENT THIRD PARTY METALLURGICAL FIRM WILL ANALYZE THE SPECIMEN. THE INVESTIGATION INTO THE CAUSE IS ONGOING AND A SUPPLEMENTAL REPORT WILL BE SUBMITTED WHEN ADDITIONAL INFORMATION IS OBTAINED. UPDATED JULY 20, 2022: ON MAY 24, 2022, THE DIRECTOR APPROVED THE REMOVAL OF THE PRESSURE RESTRICTIONS, AS ALLOWED BY ITEM NO. 5.A ON THE AMENDED CAO (ACAO) CPF NO. 2-2021-010-CAO. ON JUNE 29, 2022, THE DIRECTOR APPROVED THE REMEDIAL WORK PLAN (RWP), AS ALLOWED BY ITEM NO. 11.B. AND ITEM NO. 11.G. ON THE AMENDED CAO (ACAO) CPF NO. 2-2021-010-CAO. ON JULY 18, 2022, VIA EMAIL, TGP SUBMITTED CORRECTIVE ACTION ITEM NO 12. CAO DOCUMENTATION REPORT (CDR) AS REQUIRED BY AMENDED CAO (ACAO) CPF NO. 2-2021-010-CAO AND REQUESTED PROPER CLOSURE OF THE ACAO.