Very well put!

The risks from nuclear power are being greatly down played.

Radioactive caesium has a half life of 30 years

Caesium's half-life is 30 years, but that doesn't make it toxic.
Indeed it is its chemical similarity to Potassium ( a completely essential and non-toxic element) that means it is taken up by the food chain, bio-accumulating in long-lived species at the top of the food chain.

It is its radioactivity that is its problem, not its toxicity.
With a half-life of 30 years (hence an eighth-life of 90 years) once you have it, you have it for life.

It is extremely unlikely that it is just one species of fish that is contaminated.
Small fish are eaten by larger fish.
Each trophic level up the chain is about 10 - 30% efficient at absorbing the nutrients (including Potassium/Caesium) in its food,so the Caesium will take a while to accumulate in the top fish predators, and then in humans, if they are stupid enough to eat the fish,
but the Caesium will be around for a long time, so it is certain to happen.

And wherever there is Caesium-137, there is also Strontium-90, because fissioning U-235 produces :
U-235 + 1n => Cs-137 + Rb-96 + 3n [ 6.2% ]
U-235 + 1n => Sr-90 + Xe-143 + 3n [ 5.8% ]
and many other fission product pairings with the highest frequency of outcome centred around atomic weights of 140 and 96.
http://upload.wikimedia.org/wikipedia/en/thumb/6/68/ThermalFissionYield.svg/500px-ThermalFissionYield.svg.png
One of each fission pairing, and often both, is always radioactive, sometimes only needing one decay step to reach a stable isotope, sometimes more.

With thanks to Dave Kimble

Please, Professor Allison, the last thing we need right now are facts.

We need a whole lot more Fear, Uncertainty and Doubt, to justify our decision to ignore the inclusion of a nuclear component in our future power generation plans.

We don't like nuclear power because we don't understand it. And anything we don't understand is to be feared, isn't it?

Coal, we know well. We know how people used to make a coal fire, all of their very own, in their own fireplace. And we know how to light the gas on the stove, once mummy had shown us how to be safe.

Of course, we know all about those elegant windmills, we used to wave little versions of them around when we were kids. Wouldn't it be nice of everyone could have a little windmill on their own rooftop. Then we wouldn't have to burn any more of that nasty coal or gas.

But we can't boil a kettle with nuclear fuel in our kitchens, can we. So it must be nasty. Even mummy couldn't show us how to boil a kettle with it, and so she must think it's dangerous too.

No more facts please. We will be much happier to pay lots more money to make our baked dinner on Sundays, than listen to people trying to persuade us that mummy was wrong.

Because she was never wrong, was she.

Good article. Logic is absent today particularly in Science and the media. Environmentalism and fear rules. People fear radioactivity but are unaware it is a big part of modern day medical testing and saves many lives every day.

Wade Allison is a nuclear and medical physicist. That is why I find this article so powerful. In particular I did not know the dosages for radiation treatment which are truly huge, but clearly not fatal.
Of course, Pericles is right, people do not want facts, actual data, they want a nice dose of panic mixed with an even more enjoyable feeling of 'I told you so'.
The Earthquake in Japan was monstrous, about 8000 times as powerful as the Christchurch quake. The resultant tsunami was of almost Biblical proportions. Some official Japanese estimates put the greatest height at over 120ft, say a bit less than 40metres.
The Fukushima nuclear reactors are old, first going on line in 1971 and have all the signs of being of a late 1950s/early 1960's design. Even then the damage to human health has been relatively small. The data on that issue in the article makes that clear.
On a personal note; am I the only one who has watched the results of the earthquake and tsunami with tears in the eyes, and am I the only one who thinks the deaths of say 20000 people as a result is awful? And most important; am I the only one who finds the concentration of the media and the antinukes on the relatively trivial events at the power plant rather than those deaths to be utterly disgusting?

sarnian - your post was a prime example of what the author was talking about .. 10,000 people dead and you're essentially talking about quite slight risks once you're outside the immediate vicinity of the reactor.

Having read more comments about the reactor in recent days I'm beginning to suspect that the danger even to the workers at the plant has been highly exagerated in the media.

But once you get outside the reactor the radioactive caesium of which you are so terrified will disperse. The business about concentration up the food chain in certain areas might be possible if there was to be a continuous production of the stuff and it was reasonably concentrated in the sea water over a fairly wide are to begin with. Further, the risk can be overcome with a program of testing, or simply avoiding fishing in the area for a time.

In any case, you realise there's been an enormous fire at the gigantic refinery at Chiba, spilling megatonnes of toxic material into the atmosphere, and you're seriously worried about the caesium? From any realistic point of view the oil fire is a vastly more important source of pollution