The incident occurred at a power generator during the shutdown of one reactor unit. Hydrogen leaked from the cooling circuit of the generator due to damaged sealing. The hydrogen ignited. The fire was extinguished after 1 hour 40 minutes.

There was a massive explosion at one of the generator-turbine units of a coal-based power station. Undetected hydrogen leak from the generator was identified as a major trigger.According to the news, some workers, unaware of the leak, were trying to fix some dirt blocks and loose nuts and bearings in the generator. Just below was an oil tank. Fire sparked spread in minutes up to 16 metres, setting off the blast with a heavy noise.It took hours to control the fire. Four persons were injured.

The incident occurred at the hydrogen coolant circuit, when purging the hydrogen with carbon dioxide and air, aiming at finding a leak. Following a preliminary investigation, the power plant company explained that hydrogen was still present when air was injected, creating the condition for the formation of an explosive mixture. According to the sources referred to news mentioned in the References, it appears during the leak search activity, workers deviated from the established procedure.

A catastrophic failure of the low pressure turbine followed by fire and flooding severely damaged the generator. The main turbine automatically tripped due to an erroneous mechanical over speed signal caused by high vibrations. The reactor, which was operating at 93 percent power, received an automatic scram signal triggered by the turbine trip. The high vibration was caused by catastrophic failure of the turbine blades. Ejected blade parts ripped through the turbine casing and severed condenser tubes and other piping.

A short circuit occurred in a bus bar system in a transformer building, causing a fire in adjacent switches. This was followed by the tripping out of the three refinery turbo-alternators, cutting off the National Grid supply, and loss of refinery electrical power, steam and air supplies for some 30 minutes.The cause of the incident was a fault in a 15 kiva circuit breaker voltage transformer which led to a bus bar fault During the power loss and shutdown of plant, a hydrogen leak developed on a valve, and a tube of a fin-fan condense bank failed.

A hydrogen-cooled electricity generator exploded inside a coal-fired power plant killing two workers and injuring fifty others. An investigation into the incident found that a hydrogen gas leak may have caused the explosion, which occurred as the generator was being tested following routine maintenance.A press release of the company (see references) immediately after the accident stated that their "safety procedures may not have been followed"

A technical failure in the High-Pressure turbine blades caused high vibrations in lubricating oil pipes. Some pipes broke off and the oil leak caught fire from hot surfaces. Also the generator's hydrogen leaked out and exploded. The fire caused the loss of control air and electrical power of several safety-related components: for instance, two turbo-blowers and main heat exchanges were inoperable The fire also affected a main circulation water pipe expansion joint causing outpouring of sea water which caused the flood of the lower levels of the turbine and reactor buildings

Maintenance works were ongoing after an outage at a turbine and generator unit of the plant. Fifteen maintenance mechanics were working at that time on the unit. An access cover was removed causing the release of hydrogen and resulting in multiple explosions and fires. The explosion was heard 35 miles away. The blast tore a huge section from a building holding the six coal-fired generators of the plant and caused two fatalities and several injuries. The hydrogen was used as cooler of the unit. It should have been purged before opening the system.

On April 29, 1991, a nuclear Power Plant experienced a main generator hydrogen fire. Although a senior reactor operator (SRO) and auxiliary operators from another shift were available immediately, the need to provide personnel for the fire brigade and yet perform the many actions required by the event caused a heavy workload for the control room staff. This workload contributed to the licensee's failure to notify some key emergency response personnel as specified in the licensee's procedure.

The plant was operating at 92% power when a ground fault on a land steam exhauster caused the supply breaker to a motor control centre (MCC) to trip. This supply breaker could not be reclosed. The loss of the MCC resulted in a loss of the hydrogen side seal oil pump for the main generator that is powered from that MCC. The plant continued operation as the licensee procedures and technical manual of the turbine-generator manufacturer (Westinghouse) allow full-load operation with the hydrogen side seal oil pump shut down.