Unexplained plumes of radioactive steam have been rising from Fukushima's Reactor Building 3, Could a major meltdown be on the way?

 

Fukushima's Reactor Building 3 exploded on 13th March 2011 as a result of a hydrogen buildup, breaching the building's containment and emitting a huge plume of radiation. The reactor itself is in meltdown.

 

And now fresh plumes of steam have been seen coming out the structure. These have now been confirmed by Tepco, the owner of the nuclear plant, from 19th December onwards. The company believes the steam is coming from the fifth floor of the building.

 

However it does not know the cause of the steam. Lethal levels of radiation and the physical damage to the structure have so far made entry and inspection impossible.

Possibility 1 - a meltdown is taking place

 

The Reactor 3 fuel storage pond still houses an estimated 89 tonnes of the plutonium-based MOX nuclear fuel employed by the reactor, composed of 514 fuel rods.

 

Ever since the explosion Tepco has been concerned that if the spent fuel storage pond dries out, the intensely radioactive spent fuel rods would melt down and produce further significant radioactive emissions.

 

One possibility is that this process may now be taking place. In the event of water loss from the pond, the water would begin to overheat and produce clouds of steam, prior to a complete meltdown. If this is the case then a second major nuclear disaster at Fukushima is in the making.