Last night there was another explosion, this time in reactor No. 2 at the Fukushima Daiichi nuclear plant in Japan. This time the containment chamber was damaged and nuclear radiation is leaking out. 100 km north west of Tokyo in the city of Maebashi, authorities have recorded radiation levels ten times higher than normally and people are incouraged to stay inside.
Since the core had previously been uncovered when the cooling water levels dropped it’s now believed that a meltdown has taken place. This means that the nuclear fuel elements has become so hot that they’ve melted after which radioactive substances like cesium, xenon and iodine has been released. The technicians have been trying to cool down the reactor with sea water with added boron.
Japanese authorities have measured radiation levels of 400 millisieverts (mSv) per hour just outside the plant. After less than three hours in 400 mSv acute radiation syndrome occurs. The European limit for employees in the nuclear industry is 20 mSv per year for five years or a maximum of 50 mSv a year.
Acute Radiation Syndrome (ARS)
The lowest rate occurs at 1-2 sievert. The symptomes are nausea and vomiting for a period of more than one day, as well as fatigue, weakness and mild fever. Without qualified healthcare one out of 20 people is at risk of dying.