CSB Issues Urgent Safety Recommendations Following CITGO Refinery Accident

On Dec. 9, the U.S. Chemical Safety Board (CSB) issued urgent safety recommendations calling on CITGO Petroleum Corp. to conduct third-party safety audits and improve its emergency water mitigation system in the event of another release of potentially deadly hydrogen fluoride (HF) vapor, as occurred last July at the company’s Corpus Christi, Texas, refinery.

“CSB takes any action involving the release of HF extremely seriously,” said CSB Chairman and CEO John Bresland during a Dec. 9 press conference. “The frequency of accidents in U.S. refineries is very troubling. These accidents cost lives, inflict injuries and, as we saw in Corpus Christi, endanger communities. I call on all refineries to redouble their commitment to safer operations and safer communities.”

CSB is making these recommendations in advance of its final investigation report on the CITGO refinery incident, which is expected in August 2010. CSB issues such urgent recommendations when board members determine an imminent hazard may be present and has the potential to cause serious harm unless rectified in a short timeframe.

The Accident

On July 19, hydrocarbons and hydrogen fluoride suddenly were released from CITGO’s Corpus Christi refinery’s HF alkylation unit. The hydrocarbons ignited, leading to a fire that burned for several days. The fire critically injured one employee and another was treated for possible hydrogen fluoride exposure.

CSB investigators determined that a blockage of liquid caused by the sudden failure of a control valve led to violent shaking within the process recycle piping. The shaking broke threaded pipe connections resulting in the release of hydrocarbons, which ignited. The ensuing fire caused multiple additional fires and the release of approximately 42,000 pounds of hydrogen fluoride from equipment and piping within the unit.

The refinery used a water spray system to absorb the released HF, but the CSB cited scientific literature to conclude that at least 4,000 pounds of HF likely escaped from the unit into the atmosphere and left the facility. Investigators determined that during the first day of response efforts, CITGO nearly exhausted the stored water supply for the water mitigation system. The refinery began pumping salt water from the ship channel into the refinery fire water supply. Multiple failures occurred during the saltwater transfer, including ruptures of the barge-to-shore transfer hoses and water pump engine failures.

CSB released video of the initial pipe failure, release, ignition and fire as captured by two refinery surveillance cameras. These videos are available on CSB’s Web site.

Recommendations

CSB’s urgent recommendations call on CITGO to develop and initiate plans within 30 days to ensure an adequate water supply to the refinery’s HF mitigation system. The company should also report planned or completed actions to the Refinery Terminal Fire Company and the Local Emergency Planning Committee every 30 days until all planned activities are fully implemented.

A second urgent recommendation called on CITGO to commission independent, third-party audits of the safety of its two HF alkylation units at refineries in Corpus Christi and Lemont, Illinois. The audits should compare safety practices at the alkylation units to those recommended by the American Petroleum Institute (API). Investigators said that CITGO had never conducted such an audit of the units, despite an existing industry recommendation for audits every 3 years.

Security Questions

According to Bresland, CITGO raised objections to the CSB’s release of the surveillance video, saying that doing so would “raise substantial issues of national security” and would “only sensationalize this unfortunate accident.” CSB subsequently received affirmation from the Department of Homeland Security that the video did not fall under certain classifications requiring protection from disclosure.

During the press conference, Bresland said it was his belief that CITGO was attempting to use this national security classification “to limit public disclosure of the details of this accident for purposes unrelated to security.”

“I admonish all companies that experience significant chemical releases not to attempt to use unwarranted security labels to try to interfere with the public’s right to know,” Bresland said.

In a company statement, CITGO claimed “… by raising concerns to CSB's release of the incident videos at this time to the public, we were simply acting in good faith to maintain and preserve the security of our refinery. Moreover, CITGO has provided these videos to all the investigating agencies that requested them.”

CITGO: Committed to Operating Safely

CITGO released a statement Dec. 9 indicating the company already has taken action on the board's recommendations and remains committed to fully cooperating with the ongoing investigation.

“We hold nothing in higher regard than the safety of our employees and members of the local community,” the company said.

“Our engineering calculations of the amounts of hydrogen fluoride (HF) released were based upon and supported by thousands of air monitoring samples taken by CITGO as well as the U.S. Environmental Protection Agency (EPA) and a rigorous mass balance,” the company stated. “Through ongoing efforts and in coordination with participating organizations, we remain committed to operating safely and preventing future incidents.”

Investigations Supervisor Robert Hall, P.E., told EHS Today during the conference call that the CITGO refinery’s work force does appear committed to safety. “The workers out at the refinery are very interested in working in a safe environment and [in] the safety of the community,” he said.

Hall added, however, that CSB’s investigation findings and subsequent urgent recommendations bring some of the management systems into question. In particular, he said, it is troubling that while API recommends conducting safety audits every 3 years, CITGO has never performed one.

“I think that points to a management issue with respect to the safety culture,” Hall said.

“In general, we feel companies that are both operating refineries and are operating hazard chemical plants need to have the highest level of chemical process safety possible to make sure they operate safely day in and day out,” said Bresland. “It requires constant diligence and constant attention to process safety management.”

Bresland added that CSB hopes these recommendations, along with the final report, will continue to improve the safety of the Corpus Christi facility and other U.S. refineries.

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