Thursday, 17 March 2011

Fukushima goes global?

Two major stories have been dominating the news recently: Bahrain and Fukushima. At the time of writing, 14.15 GMT, the Fukushima one looks likely to eclipse the other.

This was the situation radiation-wise at 11 a.m. (Thu 17 March) according to the BBC Q&A site
What kind of radiation levels have been recorded at Fukushima?
Levels as high as 400 millisieverts per hour have been registered at the plant itself. A couple of hours exposed to this dose-level could cause radiation sickness. However, for long periods since the crisis began, the level has been at 10 millisieverts per hour or lower. (A spinal X-ray delivers roughly one millisievert of radiation, a CT scan of the abdomen and pelvis has an effective dose of 15 millisieverts.)
To be a global threat there has to be a thermal event strong enough to force primary radioactive material (from the fuel rods themselves) tens of thousands of feet into the atmosphere. See video.
Unless the particles get to these heights they quickly sink down and the effects remain local.

Resuming writing at 14.15 GMT , the main focus is on the pond used to store ‘spent’ fuel rods.
These are still radioactive – just not in the way needed for use in the reactor itself where heat is generated to produce steam for the turbines used in generating electricity.

The water has somehow leaked from these ponds and when this happens they heat up in a chain reaction. This can cause a very dangerous fire releasing radioactive material high into the atmosphere, where it has the potential to spread globally. This is why helicopter crews are risking their lives trying to spray water into the ponds even as radiation levels in the vicinity escalate. The helicopters have to be high to avoid lethal radiation doses and this makes it difficult to target the ponds.

Tokyo Electric are trying to restore power to operate cooling pumps but this project also is hampered by radiation levels around the plant. Yet it seems to be our best hope – and by ‘our’ I mean the world’s best hope. My understanding , and I hope I’ve got it wrong, is that hundreds of these spent fuel rods could catch fire and reach temperatures of thousands of degrees. If this sent particles miles into the atmosphere the dispersion could be truly global.

Not only could this magnify the already appalling humanitarian disaster of the tsunami several fold but the whole world economy could be affected if Japan has to withdraw reserves from the US banking system, thereby causing the dollar to collapse as one of the props supporting it is removed and as oil supplies are threatened.

Hold on tight and pray.

Author, 2077 AD