– Record-high radiation detected at Fukushima (ABC News, August 2, 2011):
The company that owns Japan’s stricken Fukushima nuclear power plant says it has detected record-high radiation on site.
Almost five months after Japan’s government announced a nuclear emergency, the company which owns the Fukushima nuclear plant, Tokyo Electric Power Company (TEPCO), says radiation levels have reached at least 10 sieverts per hour near Fukushima’s No. 1 and No. 2 reactors.
The radiation levels are more than double the previous record high that was reached in early June.
One nuclear expert predicts the clean-up from the March 11 earthquake and tsunami will be even more difficult, but there is speculation that the reading could be an aberration.
Peter Burns, former chief executive officer of the Australian Radiation Protection and Nuclear Safety Agency, says given the scale of the Fukushima emergency, the high reading is to be expected.
“The levels reported of 10 sieverts per hour are very high levels and it’s going to be very difficult to manage workers going into those areas and doing operations,” he said.
“To put the 10 sieverts into context, that 10 sieverts is actually a lethal dose of radiation. So you can’t afford to be exposed for more than a few minutes at those levels.
“It means you’re directly exposed to fuel rods in the reactors or the spent fuel ponds very closely and while it’s possible to get to those levels it means there is very little shielding going on there.”
In the week after the quake and tsunami, which triggered an explosion at the facility and a nuclear meltdown, military helicopters water bombed the power plant to try stop fuel rods and containment pools being exposed to the air.
Mr Burns says in addition to the damage, those working on the reactor now also have to contend with contaminated waste generated by the clean-up operation.
“There have been reports it’s a huge problem of a huge inventory of contaminated materials – water and other materials that are going to have to be managed over the next years,” he said.
“Obviously these have to be contained by some mechanism and then removed to various storage sites so that they can be properly managed over what will be decades.
“The ways of doing it are reasonably well known, what you have to do, but it’s just managing it on the scale that they’re going to have to manage it on would be unique in the world.”
Tony Irwin, a former reactor manager now with the Australian National University, says TEPCO has now set up a water treatment plant.
“To pump this contaminated water through this treatment plant, you remove the radioactive materials and this is the water that is now re-circulating back to cool the reactor,” he said.
“So all this water is now being contained and treated.”
AbnormalityMr Irwin says thanks to the new water treatment plant, much of the contaminated water is being contained on site and this month’s recent high readings could be an abnormality.
“I think it’s an isolated … probably some sort of debris from the hydrogen explosions. They’ve found small isolated high-radiation debris around the site and this I think [it] looks to be another one of those,” he said.
“So it’s probably only a very small area where there is this 10 sieverts an hour. They’ve found other rubble that’s one sievert an hour as well.”
The record-high reading comes as the Japan government suspends all beef cattle shipments from Iwate prefecture, north of the Fukushima reactor site.
It is the third prefecture to be slapped with a ban due to contamination fears.
Jyunichi Tokuyama from Iwate Prefecture’s agricultural department says he was stunned to learn that the contamination was found that far north.
“Iwate Prefecture is 200 to 300 kilometres from the nuclear plant, which has caused the beef to be contaminated. We didn’t even consider that the explosion would have affected us being so far away. I’m very surprised,” he said.
The Japanese government says radiated rice straw was fed to the cattle and it is also considering suspending cattle shipments in a fourth prefecture.