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Motiva Enterprises (1406), Norco

Releases of Flammable Gas

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

Hydrogen and hydrocracker units
Cause: An unexpected piping failure on an exchanger led to a release of Hydrogen and a subsequent shutdown of the hydrogen and hydrocracker units.

Followup: No

Notes: Operations personnel immediately took corrective actions to safely shut down the units and to minimize emissions. Data gathering and investigations to perform calculations and determine root cause is ongoing.

Coker Unit
Cause: Relief valve on the coker drum opened venting pollutant to atmosphere.

Followup: No

3,809.0 pounds

Coker, HCU, West Op Ground flares
Cause: Power failures due to weather (Tropical Storm Cindy) caused various releases from Motiva sources; led to total loss of electrical instrument air compressors and the loss of several steam boilers that caused the shutdown of the HCU and RCCU process units. A voltage sag caused the Coker processor to shut down which resulted in a flaring event.

Followup: No

Notes: Motiva claims that this was not preventable because of the unforeseeable weather conditions.
39,743.0 pounds

Hydrocracker unit
Cause: Flame and pilots failed on the hydrocracker flare during unit decontamination.

Followup: Yes

Notes: The flare was relit and the unit was returned to normal operation.

Hydrocracker unit, HCU Flare (EPN #4-84
Hydrocracker unit
Cause: This incident is a normal part of a turnaround. Before the Hydrocracker can be worked on, it must be cleared of hydrocarbon. This is done by venting the unit to the flare and later to the atmosphere. This venting is considered a normal but infrequent part of plant operation.

Followup: Yes


Unspecified light olefin line
Cause: An open bleeder valve was discovered during the commissioning of a 6" light olefin line, resulting in hydrocarbons escaping to the soil.

Followup: Yes

Notes: Operations closed the bleeder valve and notified the Site Supervisor. Vacuum trucks were deployed and contaminated soils were removed. The findings of the investigation were dispersed throughout operations via shift meetings and operational procedures were reviewed. The operator found to be at fault was individually met with and reprimanded by business area management.
7.4 pounds

DU-5 Unit
Cause: An atmospheric leak of light naphtha gasoline material was identified in Motiva's Distilling unit due to a piping failure on the crude column overhead line. Initially, operations personnel identified the line dripping in two locations, and vaporizing before reaching grade.

Followup: Yes

Notes: Operations developed a plan to safely remove insulation so that the leak could be stopped. Operations installed barricade tape around affected area and monitored the leak for benzene. A catch tray was fabricated and mounted directly to the crude overhead piping to contain atmospheric emissions while the associated insulation was removed from the crude overhead line. Once the insulation was removed, a pipe clamp was installed to permanently stoped the leak. The overhead piping will be replaced during the next unit turnaround in October 2006.
60,583.0 pounds

Alkylation Unit Utililty Column PV-1108
Cause: A flammable gas leak was identified in Motiva's Alkylation unit on Utility Column PV-1108. While performing sandblasting work on the vessel, a Basic Industries employee discovered a hydrocarbon leak on the vessel, and Motiva Operations was notified.

Followup: Yes

Notes: The Norco VSERT team was activated to verify that this was a hydrocarbon leak. Once this was verified, unit operators shutdown the Alkylation Unit, isolated Utility Column PV-1108, and plugged the hole in the column to stop the leak. To prevent recurrence, Motiva has made permanent repairs to the Alkylation Utility Column PV-1108 and plans to inspect it on a routine basis. Motiva now requires sandblasting contracts to have sandblasting quality control systems in place. Motiva Coordinators perform random job site audits of sandblasting work areas to assure that quality control systems are being practiced.
6,722.0 pounds

relief valve at RCCU

Cause: Depropanizer column relief valve (RV-7207) failed at the Residual Catalytic Cracking Unit, prematurely relieving below its set pressure.

Followup: Yes

Notes: Valve was isolated to stop release, "employed proper mitigation steps for alternate relief protection to prevent further environmental impact," valve removed, sent off for repair and reinstalled. It was noted that there was a noise associated with the RV piping at the time of the release--one complaint received.
85,445.0 pounds

HCU flare
Cause: Control valve 755 malfunctioned, sending hydrogen sulfide gas to flare.

Followup: Yes

Notes: Operations closed instrument air supply line, causing valve to go into fail-safe open position. Faulty instrument air filter was repaired and re-established instrument airflow to valve. To prevent recurrence, instrument air supply filter and parts of controller were replaced.
3,671.6 pounds

Hydrocracker Unit Rectifier Absorber Column (PV-822)
Cause: A pressure swing at the HCU caused relief valve on the HCU Rectifier Absorber column (PV-822) to open to atmosphere. HCU was in process of being started post-turnaround.

Followup: No

Notes: Motiva has modified a low level alarm on the HCU High Pressure Separator to mitigate the pressure swings on the Rectifier Absorber Column.
63.0 pounds

Cause: Refinery letter states that "the main air blower for Motiva's RCCU unit tripped unexpectedly which..resulted in an emergency shut down of the RCCU and RGHT units." Upon start up of RCCU, it is suspected the RCCU flare pilot was unlit causing release to air of Ethylene, Propylene, 1,3=Butadiene, VOC, Flammable Gas, HRVOC. HEAVY FLARING ALSO OCCURRED AT SHELL CHEMICAL LP but will be included in a separate report (GO-1 flare). Follow-up report states that "Motiva WAS NOT ABLE TO DETERMINE THE ULTIMATE CAUSE of the loss of the pilot flame, but that gas pressure being set above the design pressure or severe weather conditions may have contributed to the loss of pilot flame. FLARE.

Followup: Yes

Notes: RQ. Reportable quantities were exceeded during this incident. "All released materials were dispersed naturally in the atmosphere from the RCCU flare stack." Release was stopped by the re-lighting of the flare. Also flare pilot flame-out alarm was placed back into service and refresher training provided to all operations personnel on the importance of maintaining flare pilot flames. LDEQ report states that according to "LDEQ Enforcement Division, this incident is being included in an Enforcement Action being drafted by the LDEQ Enforcement Division."
33,872.9 pounds

FLARE - HCU Elevated Flare [EPN4-84], Relief Valve [RV1178 & RV1204]
Cause: Loss of electrical breaker powering most of the large motors in the hydrocracking unit caused two columns to "release to atmosphere;" RV-1178 on the Rectified Absorber Column for 30secs, RV-1204 on the Caustic Water Wash column "momentarily." FLARE.

Followup: Yes

Notes: BRQ. Refinery Follow-up Letter states "final calculations confirm that no reportable quantities were exceeded as a result of this release." Breaker loss discovered & repaired, operations returned to normal.

HCU relief valve (RV-1178)
Cause: Release caused by a loss of separation in the High Pressure Separator which caused a relief valve to release. HCU relief valve (RV-1178) relieved to atmosphere due to a loss of product separation in PV-816 (HCU High Pressure Seperator). Rectified Absorber Column (PV-822) pressure built and was relieved by opening to the atmosphere.


Notes: BRQ. Letter is predated by several months and appears to be a form. Data is accurate to the event and signed on the 17th of february.

Relief Valve at Residual Catalytic Cracking Unit
Cause: Motiva's Residual Catalytic Cracking Unit (RCCU) experienced a premature opening of a relief valve (RV) on the RCCU debutanizer column. The RCCU was operating under normal conditions at the time of the release, and operational data proves that the associated equipment did not reach the relief valve set point pressure to cause the RV to open. A contract pressure equipment company was called out to help identify any mechanical problems with the RV. Additionally, RCCU operations lowered the debutanizer column pressure 3psig aas a precautionary measure until troubleshooting efforts are completed. An update report was provided by Motiva on September 10, 2012.

Followup: Yes

Notes: A contract pressure equipment company was called out to help identify any mechanical problems with the RV. Additionally, RCCU operations lowered the debutanizer column pressure 3psig as a precautionary measure until troubleshooting efforts are completed. Upon investigation, the reportable quantity for flammable gas was exceeded in this release. 2189 pounds of flammable gas were were reported through the SPOC. The reportable quantity of flammable gas includes 1000 pounds. Refinery's attachment of listed pollutants released is too unfocused/fuzzy to read accurately.
2,189.0 pounds

FLARE: HCU flare (EPN-4-84)
Cause: The HIC on the low pressure separator (PV-817) was opened to the HCU flare (EPN-4-84) because an atmospheric relief valve (RV-4297) on the rectified absorber column (PV-822) at the Hydrocracking Unit relieved prior to its set point. Hydrocracker Flaring

Followup: No

Notes: RV-4297 was isolated and repaired. Flaring stopped once the unit was stabilized.

RCCU Flare (FE-201)
Cause: Motiva's Residual Catalytic Cracking Unit (RCCU) experienced a perceived flame outage on its elevated flare (FE-201) during planned shutdown and decontamination activities. Alarms on the RCCU Elevated Flare indicated that a flame was not present. Operations personnel went in the field and verified that a flame was actually present and the alarm was incorrect. As a precautionary measure, decontamination efforts stopped. Once flame verification was complete, decontamination efforts were restarted.

Followup: No