A second Hydrogen explosion has happened at Unit 3 of Fukushima Dai-ichi plant in Northern Japan. Similar to Unit 1 at the same location, this new explosion is likely to have been caused by the same set of circumstances.
Although the core of the Nuclear material is encased in a pill-shaped structure made from 6-inch thick stainless steel, the explosion occurred inside the concrete containment building that surrounds the pill-shaped Nuclear Vessel.
The cause of the Hydrogen gas inside the concrete containment building comes from the Zirconium Alloy that lines the fuel rod assemblies. As the heat builds up inside the Nuclear Vessel, at about 4,000 degrees, the Zirconium lining begins to melt. As this melting metal makes contact with the coolant in the Vessel, the steam generated consists of Hydrogen gas that is highly combustible.
When this Hydrogen gas ignites, the entire outer concrete containment building may explode in a massive blast. Very little radioactive material is usually released in this type of blast. The real danger is still contained in the pill shaped Vessel that houses the Plutonium and Uranium pellets in the fuel rod assemblies.
The blast from Unit 3 was so massive that it registered on the Japanese earthquake detection system as a shift in the earth’s crust. An immediate Tsunami warning was issued for the north coast of Japan once again.
Once the reading on the earthquake seismic device was determined to be the blast from unit 3 at the Fukushima Dai-ichi plant, the Tsunami warning was cancelled. The blast from the Hydrogen explosion was so massive that the estimated size of the Tsunami alert was determined to be at least 9 feet high. People from as far away as 30 miles felt the blast and believed it to be an aftershock from the massive 8.9 earthquake a few days before.
Japan has 55 operating Nuclear plants. At least two more are in danger of repeating the same course of events as those at Fukushima.
There are 2 new Nuclear power plants under construction, 1 plant that has been closed, and 11 new Nuclear Plants being prepared for construction.
Rob Robinson
