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Shell Chemical East (26336), Norco

Releases of Butadiene

LDEQ Accident Number
Accident Date
Point Source(s) Notes Amount of Release

Pump 5016B
Cause: On 12/9/12, Shell Chemical OL-5 operations discovered a pressure gauge on the piping of Pump 5016B in the OL-5 Process Unit leaking hydrocarbon. Operations personnel immediately isolated the pressure gauge to stop the leak.

Followup: Yes

Notes: Operations personnel immediately isolated the pressure gauge to stop the leak. Operations also isolated the storm drain to contain the spilled material. A pumper truck was called to remove the liquid. The pressure gauge was replaced before the pump was returned to service. No materials were released above the RQ.

OL-5 Elevated Flare (EPN 6-84)
Cause: On December 2, 2012, Shell Chemical's OL-5 Process Unit experienced an unexpected leak of the Core Exchanger, which led to flaring at the OL-5 Elevated Flare to isolate the leaking exchanger, repair, and return it to service. The release began on December 2, 2012 at 6:15 AM and ended on December 6, 2012 at 11:55 PM. Repairs were made to the core exchanger and the unit was safely returned to normal operations conditions.

Followup: Yes

Notes: The unit was secured and adjustments made to minimize flaring. Preparations were begun to complete repairs to the core exchanger. The flaring was stopped once the repairs were completed and the OL-5 process unit was safely restored to normal conditions. To prevent recurrence, maintenance practices were reviewed and improvements were made. Entire PDF report was not able to be uploaded. Contact LABB for the full report.
6,341.0 pounds

Furnace in the OL-5 Process Unit
Cause: On May 9, 2012 Shell Chemicals OL-5 Process Unit experienced a small fire during restart of a furnace. After feed to the furnace was established as part of furnace start up, a gasket on the 42" feed line failed. Hydrocarbon vapors from the leaking gasket were then ignited.

Followup: No

Notes: The valve providing feed to the furnace was closed and the fire was extinguished. Upon further investigation of the gasket failure it was discovered that recommended maintenance practices for installation of these type gaskets was not followed during this installation. After inspection it was also believed that the nuts and bolts used were worn and may have reached the end of their useful life. New quality control procedures are being put in place to ensure that the proper installation is used in future installation of this type gasket. It was also recommended that the nuts and bolts be replaced during the repair work on the flange and that closer inspections of the nuts and bolts be done during future repairs. LABB was only able to find the final follow-up; there was no facility letter. Shell estimates that there was a leakage of approximately 200lbs of quench oil which is broken down in the pollutants.

OL-5 Elevated Flare FE-101 (EPN 6-84); OL-5 Ground Flare FG-101 (EPN 7-84)
Cause: On March 12, 2012 Shell Chemical's OL-5 Unit Operators got an indication that the Process Gas Compressor (PGC) first stage control valve had opened to the flare system due to high suction pressure. The PGC turbine had slowed down causing the kickback valves to open. Slowdown of the turbine was caused by a high level in the surface condenser. The materials were released from OL-5 Elevated Flare FE-101 (EPN 6-84) and OL-5 Ground Flare FG-101 (EPN 7-84).

Followup: No

Notes: OL-5 Operations lowered the surface condenser level and the kickback flows to lower the first stage suction pressure. These actions stopped the flaring. All materials routed to flare were combusted with an approximate destruction efficiency of 99.5% released from the OL-5 Elevated Flare and Ol-5 Ground Flare to the atmosphere and dispersed naturally. Maintenance was called in to troubleshoot the surface condenser level indication. Instrument mechanics checked level controller and found dirt on the flapper nozzle. The nozzle was cleaned and proper operation of the control valve was checked. Instrument mechanics also found the door to the instrument center in the open position, which possibly allowed dirt into the enclosure. Operational rounds have been updated to include the task to check enclosure doors. Propylene is listed in the LDEQ's Verbal report as having been released as well, but there is no mention of it later on in the follow-up report from Shell. The measurements were obtained by adding the same pollutants from both flares together. Initial report states material did go offsite. Air was monitored around the perimeter of the facility. No reportable quantities were exceeded, but permit levels were exceeded for ethylbenzene, toluene, and xylene.
16.1 pounds

1-90 (GO-1 Elevated Flare, FE-602)
5-84 (West Ops Elevated Flare, FE-601)
8-84 RCCU Elevated Flare (FE-201)
Cause: On May 10, Motiva's Residual Catalytic Cracking Unit (RCCU) discovered a catalyst leak in the unit's second cyclone dip leg. Operations responded immediately and worked to isolate this section of the unit. However, due to the location of the leak it was determined the line could not be isolated without diverting the RCCU process unit to hot circulation. The diverting process required flaring at the GO-1 Elevated flare (EPN 1-90) and West Ops Ground Flare (EPN 9-84). Additional flaring occurred at the Motiva RCCU Elevated Flare (EPN 8-84). Emissions from that flare should be addressed in a separate letter from Motiva. The reintroduction of Motiva's RCCU untreated dry gas resulted in the shell GO-1 unit flaring to the West Ops Elevated Flare.

Followup: Yes

Notes: Once system was secured, Motiva's maintenance personnel began repairs at the catalyst leak point. By May 12, the repairs on the system were completed and the system was returned to service. The diversion and reintroduction of RCCU Untreated Dry Gas caused the Shell GO-1 unit to flare to the GO-1 Elevated Flare (EPN 1-90) until unit specifications were met. This flaring exceeded reportable quantities.
7.2 pounds