Tuesday, April 5, 2011

Fukushima - growing nuclear catastrophe in slow motion

 Fukushima- planetary hotspot

The Guardian has invited readers with a relevant or specialist scientific background to suggest ideas for how the dire situation at Fukushima's crippled and leaking nuclear power station might be contained.

At present, the now highly-contaminated site is storing vast quantities of water that have been hosed in, a desperate and makeshift attempt to cool the reactor cores - and even spent fuel rods.

That is the dire situation that has arisen, following the breakdown in normal cooling systems. Fukushima has been hit with a double whammy from both earthquake and tsunami damage.  The earthquake, at a massive 9.0 magnitude, damaged the reactor cores, and the tsunami knocked out power supply to the coolant systems.

It's easy to propose solutions, from the comfort of one's armchair, without worrying about one's exposure to hard penetrating radiation, but here, for what it is worth, is my advice, posting as sciencebod,  to those brave workers, who suddenly find themselves in the wrong place and at the wrong time:

"First of all, stop thinking about quick fixes, panaceas etc. Fission products continue to give off decay heat long after the control rods are inserted to absorb neutrons and stop the chain reaction. Secondly, any leakage from reactor core sends the primary fission products – notably I -131 and Cs -137 into the air, which then get incorporated into the thyroid and other body tissues, bombarding with radiation from WITHIN, so the issue is one of containment – attempting to keep the nasties on site, while protecting the workers from external radiation (they are not at risk from internal, since the hazard of ingested I-131 and Cs-137 is well known and preventable).

So how does one contain, given there are accumulations of hosed water – a make-shift remedy in view of failed pumps etc – and cracks in concrete containment ponds etc?

Desperate situations call for desperate measures – remember Red Adair, and how liquid nitrogen was finally used to tame the Kuwaiti fires started by Saddam’s retreating troops.
The chief problem at present is radioactive contaminated water that has to be disposed of to free up space for more contaminated water. Dumping it in the ocean may seem acceptable, given the diluting power of the Pacific, but it is not. It is polluting the planet. Contaminated water must be kept on site for as long as possible. But how?

Here’s the answer. When you cool water, the ice that is first formed tends to be pure water. Dissolved substances tend to stay in the water that has not yet frozen. Import ice-making machines into Fukushima, powered of diesel generators, and then periodically drain off the highly radioactive liquid below the ice (remembering that ice floats on top) and store that on site. Flush the ice briefly with fresh water to cleanse of contaminants, then let it melt in situ, and run the weakly radioactive melt into the sea.

Nope, it’s not a panacea, just an Elastoplast job, but it might help preserve a shred of credibility for the nuclear industry if it can contain its problem, instead of using the sea as a convenient dump. And let’s not forget that not all nuclear reactors are situated on coastlines, so my “ice solution” might be one they should consider on inland river locations etc. in the event of a problem comparable to Fukushima.

I have also posted a copy to the Independent, where I blog as newsjunkie.