Nearly six years ago, the devastating Japanese tsunami smashed into the Fukushima Daiichi nuclear power plant. Things quickly spiraled out of control, and the world watched in horror as three of nuclear reactors melted down. While Japanese authorities scrambled to solve the problem, it soon became clear that it wasn’t going to be a quick-fix. Now, after a camera found a hole in the grating beneath the containment unit, and new readings from inside the second reactor are at “unimaginable levels.” That doesn’t mean, however, that they’re rising–only that areas that researchers weren’t able to access are now accessible.
The readings, taken by analysts at the Tokyo Electric Power Company, (Tepco) were found to be far higher than any previous ones. According to The Japan Times, radiation levels are at 530 sieverts per hour, while the previous high, recorded back in 2012, was 73. Sieverts are a measuring scale based on radiation’s effect on the human body.
“A single dose of one sievert is enough to cause radiation sickness and nausea,” explained Justin McCurry for The Guardian. “Five sieverts would kill half those exposed to it within a month, and a single dose of 10 sieverts would prove fatal within weeks.” Luckily, according to reports, there are no signs that the recently examined reactor is leaking radiation into the ocean.
The findings occurred when Tepco used a telescopic camera to look deep inside reactor number two last week. What they found was frightening, and hasn’t been fully explained. The metal container that held nuclear material inside the larger containment unit had melted through the bottom, creating a large hole in the grating underneath it.
“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,” Tepco spokesman Tatsuhiro Yamagishi told Agence France-Presse. “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.” One of those images, in particular, showed something interesting: what might be the first spent nuclear fuel rods discovered.
While the 530 sieverts is extraordinarily high, experts don’t expect it to be the highest. “Similar remote investigations are being planned for Daiichi Units 1 and 3. We should not be surprised if even higher radiation levels are found there, but only actual measurements will tell.”
The decommissioning project is a long-term thing. Expected to take up to 40 years, it’s a big, complicated, and dangerous job. Estimates by the Japanese government put the cost upwards of $190 billion dollars.