I was at a physics lecture about Fukushima given two weeks ago at the University of Cape Town. Here are some facts you may or may not know:

1. The event of a serious nuclear catastrophe is 1 in every 10000 years per nuclear plant.

2. There are between 400-500 nuclear plants in the world.

3. That means we can expect 1 Chernobyl or worse every 20 years.

4. When these events happen, the consequences last forever, it takes tens of thousands of years for the land to recover.

5. That means within 500 years, if the number of nuclear plants stays constant (at 500), we would have at least 25 city-sized exclusion zones around the world.

6. These numbers only include nuclear power plants, they don't include nuclear subs, warheads etc.

7. These numbers exclude future advances in nuclear reliability though they may only be asymptotic (Pareto). Most of the advances have likely been made already.

8. If we were to increase our nuclear power output, so as to be less reliant on coal, they reckon we would need to double the number of nuclear power plants.

9. That means we can now expect 1 Chernobyl or worse every 10 years.

10. That means within 500 years, if the number of nuclear plants stays constant (at 1000), we would have at least 50 city-sized exclusion zones around the world.

11. When a Chernobyl or worse happens, the fallout covers entire continents, leading to a number of indirectly attributable deaths from thyroid cancer and other cancers.

12. These probabilities are based on pure physics, they do not factor in negligence on the part of humans, tiredness, lack of funding, depreciation of plant, government intervention, mismanagement etc. For instance in South Africa, at the Koeberg nuclear plant, a loose bolt accidentally destroyed a power generator, and last year in September, 91 workers were accidentally exposed to very low doses of radiation (this was not widely reported to the media, and it is not clear that an investigation was ever conducted into the matter).

13. Coal plants and mining plants leak radiation on a daily basis.

14. Our parents teach us not to play with fire. Yet fire, when handled with respect and care, is a powerful technology.

15. Nuclear power, is also a fire, and a powerful technology, but it is an "eternal" fire. When a nuclear disaster occurs, the consequences are forever.

16. It is a question of asymmetric odds. The event of a disaster is remote. It is so remote that the apparatus of our human mind finds it difficult to comprehend. These events do happen, and when they do, they must be amortized over thousands of generations.

17. Only a fool would play Russian roulette at 6-1 odds. Long Term Capital Management included minds of Nobel Prize calibre, yet they played it with better odds and lost. Then they tried again under a different name and lost. That didn't stop them from trying yet a third time: http://en.wikipedia.org/wiki/Long-Term_Capital_Management

18. LTCM played the game of asymmetric odds on behalf of a fund of investors. Are we prepared to play it on behalf of generations? Even thousands of generations yet to be born? Do we have the right?

18. If it were a question of pure physics, then Nuclear power may appear to be safe and controllable. But it is also a question of people, of incentives, business deals, governments, and of consequences over future generations for which we have no right to take responsibility. We need a safe and simple power (or a combination of these).

19. The trouble with Nuclear power (and I say this as someone who was once a naive supporter) is that there are too many variables. There are hundreds of variables within the realm of physics and there are hundreds more outside. We know from other disciplines, that humans (no matter how smart) are simply just not good enough at controlling variables like that.

20. We cannot trust our models to control these things for us. Some models are more useful than others, but ultimately our models fail, whether they be Newtonian physics, or Black Scholes, that is what makes them models, they are approximations of the data that we have at hand. The question is whether we can deal with the situations that arise when our models fail us. A financial meltdown? A plane crash? A destruction of a city for tens of thousands of years?