日本原子力研究開発機構
A partial meltdown was reported to be possible at unit 3. At 13:00 JST reactors 1 and 3 are vented to release overpressure and then re-filled with water and boric acid for cooling, and to inhibit further nuclear reactions. Unit 2 was possibly suffering a lower than normal water level, but was thought to be stable; although pressure inside the containment vessel was high. The Japan Atomic Energy Agency announced that it was rating the situation at unit 1 as level 4 (an accident with local consequences) on the International Nuclear and Radiological Event Scale.