A subcontractor employee was using a band saw to cut a 1" metal pipe when a flash fire occurred on the third floor hydrogen fluoride area. Subcontractor employees were removing all piping associated with the Anhydrous Hydrofluoric Acid (AHF) system. These lines were being removed during plant decontamination and demolition (D&D). The subcontractor employee was attempting to cut a 90-degree elbow located at the highest elevation on the 1" line, but the lowest elevation of the overall piping run.
Several workers sustained minor injuries and millions of dollars worth of equipment was damaged by an explosion after a shaft blew out of a check valve. The valve failure rapidly released a large vapor cloud of hydrogen and hydrocarbon gases which subsequently ignited.Certain types of check and butterfly valves can undergo shaft-disk separation and fail catastrophically or "blow-out," causing toxic and/or flammable gas releases, fires, and vapor cloud explosions. Such failures can occur even when the valves are operated within their design limits of pressure and temperature.
A battery that was left on a charger over a given weekend was used to start a gasoline power generator. This battery was connected in series with another battery and the connection on the negative post was hand tightened. When an attempt was made to start the generator, the battery exploded on approximately the fifth click of the starter solenoid. No damage was done to any equipment or facilities and no one was injured.
One man was killed and another severely injured while working with a portable battery power supply.
At a test facility, a water-submersible portable battery power supply was used to power lighting. The battery power supply contained two 12-volt lead-acid automotive batteries, a wiring harness, and switching relays mounted in an air-tight case suitable for submersion in water. The case possessed ½-inch aluminum walls and a 13.8-pound lid. The box had been used periodically over two years.
An operation to increase the pressure within a hydrogen tube-trailer to 6000 psig was in progress when a burst disk failed at approximately 5200 psig and hydrogen was released. A vent line attached to the burst disk was not sufficiently anchored and bent outward violently from the thrust of the release over an approximate 4-inch moment arm, causing considerable damage to the adjacent vent system components. The operation is conducted with personnel present, but fortunately no one was in proximity when the burst disk failed.
A pressure relief device (frangible burst disk) on one of a hydrogen delivery tube trailer's 26 tubes failed prematurely and released hydrogen while filling a hydrogen storage tank at a government facility (see Attachment 1). Prior to the filling process, all procedures and safety checks, including connection to the facility's regulator/distribution control system with leak checking and follow-up verification of leak checking by facility personnel, were completed (see Attachment 2 for more details).
In the fall of 2007, the operations team began a procedure (a written procedure was being followed) to sample the liquid hydrogen (LH2) storage vessels ("tanks"), and associated transfer system. This procedure was being performed to determine the conditions within the system, and if necessary, to purge the system of any excess gaseous hydrogen (GH2) in preparation for reactivation of the system. The system had not been used since 2003.
Only 25 minutes after the normal work shift ended, an explosion occurred at a hydrogen storage and use facility that had been in a non-operational mode for several months while undergoing modifications for future tests. No one was in the facility at the time of the explosion. The event was viewed about 30 seconds after the explosion by two engineers in a blockhouse 1000 feet away. Authorities were notified and calls were placed to other personnel needed to secure the area. About 8 minutes later, the engineers moved to a vantage point about 450 feet from the facility.
The evaporator pad in a fuel cell power unit installed in a hydrogen-powered forklift caught fire during operation. The evaporator pad is used for wicking the product water created by the fuel cell. The operator dismounted the forklift, observed flames coming from the fuel cell unit, and called for help. The facility fire brigade used a fire extinguisher to put out the fire. The upper left corner of the fuel cell evaporator pad was burned entirely; the plastic bracket that holds the evaporator pad in place was distorted; there was some discoloration of the radiator.
A fuel cell forklift operator stated that he observed a "ball of fire" coming from the left side of the forklift that seemed to flash and extinguish. Investigators found no external signs of a fire, but the forklift would not start. The fuel cell power pack access panel was removed to enable investigators to search for any internal signs of a fire. Some areas inside the fuel cell stack appeared to have experienced an electrical arc or some type of overheating. All connections were verified to be tight and secure.