Nuclear Power Plant Explosions at Fukushima-Daiichi

Abstract

The Great East Japan Earthquake on March 11, 2011 generated a series of large tsunami waves. The tsunami waves reached area deep within the units at Fukushima Daiichi nuclear power plant. The station blackout and loss of all instrumentation and control systems at reactor 1-4 at Fukushima Daiichi nuclear power plant caused the loss of control and cooling means of three reactor units that were operational up to the time of the earthquake. These three reactor cores were heated up due to reactor decay heating. Severe damage of the fuel and a series of explosions occurred. The explosions of unit 1 and 3 at Fukushima Daiichi nuclear power plant have been investigated using image processing. The explosion of unit 1 is a typical gas explosion with the following steam release from the reactor container vessel. It seems that the destruction of the reactor building of unit 3 initiated by the major leakage from the reactor container vessel or gas explosion and following massive release of internal fluid accelerated the structural destruction. The ejected flammable gas burned as a counter flow flame on the roof of the reactor building of unit 3.