Radiation levels are so high inside Fukushima’s crippled nuclear reactors that a robot designed for such conditions would only have about 2 hours to explore the reactors before becoming disabled, and even a brief visit could kill a human being.
Six years after a powerful earthquake and a massive tsunami crippled the Fukushima Daiichi nuclear power plant near Sendai, Japan, scientists have detected the highest levels of radiation to date inside reactor No 2.
Tokyo Electric Power Company (TEPCO), the operator of the Fukushima site, used a camera on a telescopic arm to peek inside the reactor at the beginning of February. They discovered that the material housed inside the pressure vessel – the metal capsule used to hold the nuclear material within the containment unit—had likely melted through the receptacle’s bottom and created a 3-foot hole in the grating that lies underneath.
Black debris is visible in the images and is believed to be some of the melted nuclear fuel that has only now been spotted by TEPCO. The fuel likely melted through the pressure vessels in the other 2 reactors as well. Fortunately, the material is not a risk outside of its protective barrier.
TEPCO – which has fed the public lies about the extent of the disaster from day 1 – has yet to confirm the finding. TEPCO spokesman Tatsuhiro Yamagishi says:
“It may have been caused by nuclear fuel that would have melted and made a hole in the vessel, but it is only a hypothesis at this stage. We believe the captured images offer very useful information, but we still need to investigate given that it is very difficult to assume the actual condition inside.”
However, exploring may be difficult. TEPCO analysts measured the contamination in the reactor by examining the electronic noise caused by radiation in the images taken near the pressure vessel and found that the area is contaminated by 530 sieverts of radiation per hour. The previous high, recorded in 2012, was 73 sieverts.
To give you an idea of how outrageously high the radiation level in reactor No 2 is, consider this: If you were exposed to 1 sievert, you could suffer radiation sickness, infertility, and cataracts. Being exposed to 10 sieverts would leave you with only weeks to live. TEPCO says that their estimate has a margin of error or 30%, but it doesn’t matter. Even 159 sieverts is shockingly high.
The discovery does not mean that radiation levels have been rising. Radiation had not been measured in this particular location, so it may have been that high all along.
And since the reading was taken some distance from the melted fuel, it could actually be 10 times higher than 530 sieverts.
But even robots can’t withstand such immense radiation. TEPCO has been using remote-controlled robots to explore Fukushima and assess the extent of the damage. Last spring, it was reported that as soon as the robots got close to the reactors’ wiring, the robots simply “died.” And at 530 sieverts, the robots, which take 2 years to develop, can only last about 2 hours before they become useless. This puts a major kink in TEPCO’s plan to start taking out the reactor’s fuel by 2021.
“It will be very difficult to operate robots in there for a long time to come, and to remove the melted fuel. So the finding might greatly affect the decommissioning time schedule.”
It could take 40 years to clean up the Fukushima site. Yet, despite facing an unprecedented cleanup effort, Prime Minister Shinzo Abe has been pushing to restart reactors shut down following the 2011 disaster.
“It’s unbelievable that anyone would want to restart nuclear plants when Japan hasn’t learned how and why the Fukushima Daiichi accident happened, or learned lessons from it.”