– Radioactivity down to one-fifth of July levels (NHK, August 17, 2011):
The Japanese government and Tokyo Electric Power Company say the amount of radioactive material being emitted from the Fukushima Daiichi nuclear plant has dropped to one-fifth that of a month ago.
The government and TEPCO said on Wednesday that maximum radiation levels around the plant during the past 2 weeks were 200 million becquerels per hour.
This is one-fifth the levels detected in July, and one-10 millionth the levels in mid-March, shortly after the troubles began at the plant.
The state minister in charge of the nuclear crisis, Goshi Hosono, said the maximum reading of 200 million becquerels is just an estimate because the exact emission levels cannot be accurately measured.
He pledged to seek methods for making precise measurements and for containing radioactivity inside the plant.
The government and TEPCO said there is no major change in their timetable for bringing the plant under control, and that their goal continues to be to achieve cold shutdown of the reactors while processing contaminated wastewater and reducing radioactive emissions.
TEPCO says they are planning a “cold shutdown” of the Fukushima Dai-ichi nuclear plants in 6 to 9 months.
“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.
The government said it will draw up a plan for decontaminating the current evacuation zone by the end of August, and it will launch a model decontamination project early next month.
Experts say that before the government allows residents to return to the evacuation zone, it will be necessary to prevent new leakage of radioactive material, as well as decontaminate material already leaked and dispose of mud and sludge generated by the decontamination process.