Unit 3 Hydrogen Explosion — Larger Blast, Mixed-Oxide Fuel

At 11:01 JST on March 14, an even more powerful hydrogen explosion destroyed the Unit 3 reactor building, sending a large debris cloud thousands of feet into the air. Unit 3 was loaded with MOX (mixed-oxide plutonium-uranium) fuel, raising concerns about plutonium dispersal. Eleven workers were injured. The explosion damaged Units 3 and 4 interconnections. Operators continued seawater injection attempts with fire trucks as all normal cooling pathways were lost.