Japan: Radioactive Iodine-131 In Reactor No. 4 Spent Fuel Pool At 22,000 Times Normal

– Japan to Assess Its Dumping of Toxic Water (Wall Street Journal):

According to Tepco, nearly 27,000 tons of water in total was pumped into the most heavily damaged reactors, Nos. 1, 2 and 3. Each reactor facility is designed to hold about 300 tons of water.

“We wanted to avoid releasing radioactive water into the ocean. But that was an unavoidable operation,” Mr. Nishiyama said. “We also failed to provide proper notice to neighboring countries.”
…
A new concern arose late Wednesday with the discovery that water in reactor No. 4’s spent fuel pool was vastly more radioactive than normal. A water sample taken Tuesday contained 220 becquerels of iodine-131 per cubic centimeter. That compares with a level of just 0.01 becquerels or less for normal spent-fuel pools. Such pools allow used nuclear fuel to slowly cool down over a matter of years.

See also:

– TEPCO Admits Damage To Part Of Fukushima Reactor No. 4 Spent Nuclear Fuel Pool – Japan Government: ‘We Must Devise Some Ways’ To Reinforce The Quake Resistance Of The Buildings, Where Radiation Levels Are High

– Chief Nuclear Engineer Arnie Gundersen: ‘Worst-Case Is the Unit 4 Fuel Pool, Which Has Enormous Amounts of Plutonium And Depleted Uranium’ ‘If That Catches Fire It Could Devastate A Large Area’