Largely absent from most mainstream media reports on the Fukushima Daiichi nuclear disaster is the fact that a highly-dangerous "mixed-oxide" (MOX) fuel in present in six percent of the fuel rods at the plant's Unit 3 reactor. Why is MOX a big deal? According to the Nuclear Information Resource Center (NIRS), this plutonium-uranium fuel mixture is far more dangerous than typical enriched uranium -- a single milligram (mg) of MOX is as deadly as 2,000,000 mg of normal enriched uranium.
"In the event of such accidents (involving the accidental release of MOX), if the ICRP (International Commission on Radiological Protection) recommendations for general public exposure were adhered to, only about one mg of plutonium may be released from a MOX facility to the environment. As a comparison, in [sic] uranium fabrication facility, 2kg (2,000,000 mg) of uranium could be released in the same radiation exposure."
Amazingly, most mainstream reports that mention MOX discount it as a non-threat. But the truth of the matter is that the threat posed by MOX is very serious. The NIRS report explains that inhalation of MOX radioactive material is significantly more dangerous than inhalation of normal uranium radioactive particles.