Desperate to be seen to be doing something (or is it because
they are afraid of upsetting the powers that be) Governments worldwide
are plumping for nuclear power rather than renewable energy to
counter global warming. As we reported in the last two issues
of Green Health Watch, this makes things look pretty bleak, what
with (i) the huge potential for radioactive contamination and
(ii) the fast vanishing supplies of high-quality uranium ore.
Another alternative, albeit nuclear, was rejected by the European
Commission in 1999 and 2000: a much safer way to produce nuclear
energy called 'accelerator-driven system (ADS)' using a much less
radioactive substance, thorium.
In an 'accelerator-driven system' (ADS), a very strong external
beam of protons is needed to trigger and maintain the heat-generating
reactions. If a reaction appears to be getting out of control,
you simply switch the proton beam off. In an ADS, the chain reaction
which can become an atomic bomb or melt down a conventional reactor,
could only occur through utter negligence or sabotage by an insider.
A fault or, for instance, a bomb, would halt the reaction instantly.
On the other hand, a terrorist bomb on a conventional reactor
could contaminate land and people for hundreds, may be thousands
of miles. Professor Egil Lillestol* estimates that the technology
would require only 550 million euros and 15 years to develop.
One major remaining problem is how to safely contain the molten
lead (highly corrosive) used in the ADS process.
There is three times as much thorium as uranium in the Earth's
crust. It produces 250 times more energy than uranium. Thorium
waste loses its radioactivity in hundreds of years rather than
tens of thousands. So what's the problem? Australia has the world's
largest reserves of thorium, but India, which is sitting on about
a quarter, has already planned its transition to ADS-thorium reactors.
Egil believes that the prime objection to both EU and global investment
in ADS-thorium technology is more political than scientific. The
countries which currently supply or process uranium ore are, understandably,
not supportive. Nor are the countries which are still jealously
guarding nuclear-uranium know-how. Those which have ADS-thorium
know-how are also, to some degree, keeping it to themselves and
working on different prototypes rather than pooling their expertise.
Developing ADS-thorium technology within a relevant global warming
timescale will demand (i) an acceptance that global power balance
will shift from oil and uranium-owning nations to thorium-owning
nations, and (ii) an unprecedented level of international cooperation
* professor at the Institute of Physics and Technology, University
of Bergen (Norway)