Radiation is at its highest since the 2011 meltdown.
The radiation levels inside Japan’s damaged Fukushima Daiichi nuclear reactor No. 2 have soared in recent weeks, reaching a maximum of 530 sieverts per hour, a number experts have called “unimaginable“.
Radiation is now by far the highest it has been since the reactor was struck by a tsunami in March 2011 – and scientists are struggling to explain what’s going on.
The previous maximum radiation level recorded in the reactor was 73 sieverts per hour, a reading taken not long after the meltdown almost six years ago. The levels are now more than seven times that amount.
Exactly what’s causing the levels to creep upwards again is currently stumping the Tokyo Electric Power Company (Tepco). But the good news is that they say the radiation is safely contained within the reactor, so there’s no risk to the greater population.
The latest readings were taken near the entrance of the No. 2 reactor, immediately below the pressure vessel that contains the reactor core.
To get an idea of the radiation levels inside, the team used a remote-operated camera to take photos of the area – the deepest point in the reactor to date – and then analysed the electronic noise in the images to measure radiation levels.
The technique has an error margin of plus or minus 30 percent, which means that it’s not highly accurate. But even at the lowest end of the measurements, the levels would still be 370 sieverts per hour – and could be as high as 690 sieverts per hour.
These unexpectedly high levels are complicating Tepco’s plan to decommission the nuclear reactor. The most recent aim was to have workers find the fuel cells and start dismantling the plant by 2021 – a job that’s predicted to take up to half a century. (Click to Article)