Schematic view of the Fukushima Daiichi nuclear power plants. Schematic view of a plant building and its vicinity. We, science communicators at Miraikan, are providing information concerned with the earthquake, the tsunami, and the Fukushima Daiichi nuclear power plant, which helps you to understand the issues up front. Why did the hydrogen explosions happen at the Fukushima nuclear plant?. Because of the explosion at reactor 1, the building shell violently collapsed on March 12th.
The same type of explosion occurred at reactor 3 on March 14th, and at reactor 4 on March 15th. The wall of the building shell is ferroconcrete 1m-thick, so you can imagine how fierce the explosions were. This is the opposite of what we find for heavier gases such as propane or gasoline fumes, which hover near the ground, creating a greater danger for explosion.
With the exception of oxygen, any gas can cause asphyxiation. Hydrogen is nontoxic and nonpoisonous. Hydrogen does not create "fumes. More safety information about hydrogen can be found at the following websites: www. Amid the wreckage. McCullough noted that "Ohio Power Co. Cooling things down. Water from fire hoses sprays on a hydrogen delivery truck and the surrounding area to keep the area cool after the explosion. A prompt response. A fireman walks through debris near a hydrogen delivery truck after the explosion.
The local fire department arrived quickly on the scene to assist the other emergency response teams in fighting the fire and aiding injured workers. In the aftermath of the incident at the Muskingum River Power Plant, AEP personnel conducted their own examination into the cause of the explosion. Due to the fatality and the injuries sustained by workers at the facility, the U.
The device had been replaced by the hydrogen vendor several months prior, when the vendor was on-site to make repairs related to an apparent leak. The replacement relief device assembly did not have a fusible plug to support the disc. When the rupture disc failed, the disc, or a piece of fusible plug left in the vent pipe during the replacement several months prior to the explosion, penetrated a bend in the piping, permitting the hydrogen to vent lower down in the area of the tanks as well as up the normal vent path, McCullough explained.
OSHA brought enforcement actions against the involved entities as a result of the findings from its investigation of the incident. Hydrogen fires are invisible and if a worker believes that there is a hydrogen leak, it should always be presumed that a flame is present. When workers are required to fight hydrogen-related fires , employers must provide workers with necessary protective gear to protect them from such invisible flames and potential explosion hazards.
There are several OSHA standards that may apply to employers who produce or use hydrogen. These contaminants, particularly magnetite, can block the water makeup ports and the drain valves. This was found to be the case on 6 makeup ports and on most drain valves. The blocked drain valves made it very difficult to clean the cells and to unblock the makeup ports.
Recommendation 2 - Replace the existing low-purity LP purity analyzer with a fail-safe model that ensures the vent valve is opened under the conditions described above. Carry out a risk assessment of the current LP purity analyzers to determine the level of risk associated with a loss of sample flow. Recommendation 3 - Fit hydrogen purity analyzers that fail safe either between the stages of the compressor or immediately after the compressor.
Carry out a risk assessment of the current LP and HP purity analyzers to determine the level of risk associated with a loss of sample flow failure. Recommendation 4 - Fit pot-type water seals with open trough water makeup as a replacement for the existing U-tube and pot-type seals The original design drawings for the gasholder show the inlet and outlet pipes extend 50 mm above the water line. The actual measured extension was less than 20 mm. Small variations in the level control could allow water to enter the lines.
Recommendation 5 - The building is fitted with partially closed-in ends that can trap the gas under the roof. The current construction standard for this type of facility is to have the storage banks in an open area rather than inside a building of any kind.
Any leakage will then quickly disperse into the atmosphere and not form an explosive mixture. This is not practicable at the current plant, but improvements are possible. Recommendation 7 - Conduct an investigation into the feasibility of establishing a gas-up station away from the hydrogen generation plant, possibly near the CO2 plant, to allow the units to be gassed from transportable pallets in an emergency.
Ignition Source. Summary A hydrogen generation plant experienced a fire and significant damage due to a concussive combustion event that started in a high-pressure hydrogen feed pipe. System Description A certain hydrogen plant is designed to continuously produce hydrogen at a purity of
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