Normal SFP Iodine-131 level is 0.01 becquerels or less:
– Japan to Assess Its Dumping of Toxic Water (Wall Street Journal):
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.
“Cold shutdown” means the reactor cores – and the used fuel pools – decrease in temperature through 100 degrees C and continue to go down after a couple of days without additional cooling. If that doesn’t happen within 48 hours, it isn’t going to. E-V-E-R. The reactors are still ‘in service’ – which means the fuel is still reacting. It hasn’t happened at Fukushima and it never will.
More on SFP and Reactor No. 3 here:
Watch the video here.
– Radiation high at No.3 reactor pool (NHK):
The operator of the troubled Fukushima Daiichi nuclear plant has detected high levels of radioactive materials in the spent fuel pool of the No.3 reactor at the plant.
Tokyo Electric Power Company examined a water sample from the pool on Sunday. The sample contained 140,000 becquerels of radioactive cesium-134 per cubic centimeter, 150,000 becquerels of cesium-137, and 11,000 becquerels of iodine-131.
None of these substances were detected during an inspection on March 2nd, before the accident triggered by the March 11th disaster.
TEPCO says these substances may have come from damaged fuel rods in the reactor rather than the damaged spent fuel rods in the pool, because it has detected radioactive iodine, which has a short half-life. Radioactive substances such as iodine are generated during nuclear fission inside a reactor.
The company says the radioactive substances may have become attached to debris and entered the pool together.
Footage from the pool at the No.3 reactor on Sunday showed debris, believed to have been caused by a hydrogen explosion, scattered all over the interior of the reactor building.
The levels of radiation detected are almost the same as those detected in April in water samples in the fuel pool of the No.2 reactor.
Tuesday, May 10, 2011 20:22 +0900 (JST)