The two fatal accidents, which were investigated by CSB, include the June 9, 2009, explosion at the ConAgra Slim Jim plant near Garner, N.C., that fatally injured four workers and injured 67 others; and a Feb. 7, 2010, explosion at the Kleen Energy natural gas powered electric generating plant under construction in Middletown, Conn., that killed six workers and injured at least 50 others.
These incidents involved the intentional release of flammable natural gas into work areas, putting workers and nearby communities at risk of fires and explosions. At the Kleen Energy facility, workers were conducting a "gas blow," a procedure that forced natural gas at high volume and pressure through newly installed piping to remove debris. The gas was vented to the atmosphere, where it accumulated, came in contact with an ignition source and exploded.
At the ConAgra facility, workers were purging a pipe feeding gas to an industrial heater. During the purging operation, gas was allowed to flow through the pipe and exit through an open valve inside the utility room where the water heater was located. Flammable gas accumulated inside the building and eventually found an ignition source.
Deadly Practices
CSB’s 15-minute video, “Deadly Practices,” includes animations that show the hazards of releasing gas into areas where it can accumulate, ignite and kill or injure workers or members of the public. The video is available online at http://www.csb.gov and on the CSB’s YouTube channel.
“The deadly accidents at Kleen Energy and ConAgra were entirely preventable,” CSB Chairperson Rafael Moure-Eraso said in the video. “At the Chemical Safety Board, it is our hope that standards will be put in place that will require these safer practices, which we believe will save lives.”
As a result of CSB’s investigation, the board released urgent recommendations aimed at preventing future tragedies. CSB recommended that OSHA promulgate regulations that address fuel gas safety for both construction and general industry.
In the video, Don Holmstrom, CSB’s Lead Investigator into both of these incidents, speaks to a key recommendation on cleaning piping at power plants. “The CSB believes that the use of flammable natural gas in gas blows is inherently unsafe and alternate methods should be used,” he said.
In September 2010, Connecticut Gov. M. Jodi Rell issued an executive order banning the use of natural gas blows during power plant construction in the state. The National Fire Protection Association (NFPA) and the International Code Council (ICC) are taking action to ban the use of natural gas for cleaning and purging pipes.
