– 720,000 Terabecquerels of Radioactive Materials in 100,000 Tonnes of Contaminated Water (EX-SKF, June 3, 2011):
That water is estimated to contain 720,000 terabecquerels of radioactive iodine and cesium.
That’s another “Level 7” right there.
That’s more than what has been released into the atmosphere, which the Nuclear Safety Commission estimates to be about 630,000 terabecquerels and Nuclear and Industrial Safety Agency estimates to be about 370,000 terabecquerels.
I personally think this air radiation numbers underestimate the true numbers, particularly the number from NISA. At that time (mid April), NISA said they calculated the number based on the amount of radioactive materials they estimated to be still inside the RPV. At that time, NISA assured everyone that the fuel rods were only partially damaged and they were all inside the Reactor Pressure Vessels. Now we know (and they should have known) that the RPVs were breached very early in the accident, and the melted core had at least partially escaped out of the RPV by the time they made the estimate.
Now, Fukushima is slowly approaching Chernobyl.