2007 — Oct 2, Fire, 1,000 deep tunnel at Xcel hydroelectric plant, Georgetown, CO — 5

— 5 CSB. Investigation Report. Xcel Energy Hydroelectric Plant Penstock Fire. Aug 2010.
— 5 NFPA. “2007 Multiple-Death Fires.” NFPA Journal, Sep/Oct 2008, p. 60.

Narrative Information

CSB Executive Summary: “Incident Synopsis. On October 2, 2007, a chemical fire inside a permit-required confined space at Xcel Energy‘s hydroelectric plant in a remote mountain location 45 miles (72 kilometers) west of Denver, Colorado, killed five and injured three workers. Industrial painting contractors were in the initial stages of recoating the 1,530-foot (466-meter) steel portion of a 4,300-foot (1,311-meter) enclosed penstock tunnel with an epoxy coating product when a flash fire occurred. Flammable solvent being used to clean the epoxy application equipment in the open penstock atmosphere ignited, likely from a static spark. The initial fire quickly grew as it ignited additional buckets of solvent and substantial amounts of combustible epoxy material, trapping and preventing five of the 11 workers from exiting the single point of egress within the penstock. Fourteen community emergency response teams responded to the incident. The five trapped workers communicated using handheld radios with co-workers and emergency responders for approximately 45 minutes before succumbing to smoke inhalation.

“…Scope of the Investigation. Catastrophic workplace accidents typically are not the result of a single error or one piece of faulty equipment; rather, higher-level safety system deficiencies are often found at facilities where such accidents occur. It has also been established that accident prevention is most effective when these systemic causes are understood and learned. As such, the U.S. Chemical Safety Board (CSB) examined both the technical and organizational causes of the fire at Xcel Energy‘s Cabin Creek penstock.

“The investigation found that a number of safety issues contributed to the accident, including a lack of planning for hazardous work, inadequate contractor selection and oversight, and insufficient regulatory standards pertaining to the use of flammables within confined spaces. The investigation also examined the technical aspects of recoating a penstock, the work conditions of the unique confined space, and the training the contractors received prior to starting work. Finally, the CSB evaluated aspects of emergency response, including planning for timely and qualified rescue and the need for certified confined space rescue responders in the state of Colorado.

“…Incident Description. On October 2, 2007, a work crew of industrial painters employed by RPI Coating, Inc. (RPI) began applying a new epoxy coating to the steel interior section of the penstock at the Cabin Creek hydroelectric plant operated by Xcel Energy, Inc. (Xcel), located south of Georgetown, Colorado.

“Shortly after the epoxy application commenced, the work crew experienced problems with the spraying process, resulting in poor coating quality. Spraying was terminated and the crew began cleaning the sprayer system equipment with a flammable solvent, methyl ethyl ketone (MEK), to remove epoxy residue before taking the equipment out of the penstock. During this cleaning operation, MEK vapors inside one of the two epoxy hoppers ignited and flashed. The resulting fire grew quickly, consuming several other open containers of MEK and numerous buckets of epoxy material positioned around the sprayer.

“Four RPI crew members positioned on the side of the fire nearest the exit evacuated the penstock, although three were later treated for injuries: one received minor burns, one fractured his arm, and another suffered breathing difficulties. Five additional crew members trapped opposite the exit were unable to evacuate due to the fire and narrow configuration of the penstock. The five workers later succumbed to smoke inhalation inside the penstock and died….” (CSB. Investigation Report. Xcel Energy Hydroelectric Plant Penstock Fire. 2010, pp. 10-12.)

Sources

National Fire Protection Association. “2007 Multiple-Death Fires.” NFPA Journal, Sep/Oct 2008, pp. 57-63.

U.S. Chemical Safety and Hazard Investigation Board. Investigation Report. Xcel Energy Hydroelectric Plant Penstock Fire. Washington, DC: CSB Report No. 2008-01-1-CO, Aug 2010, 180 pages. Accessed 5-31-2016 at: http://www.csb.gov/xcel-energy-company-hydroelectric-tunnel-fire/