Yahoo Tuning Groups Ultimate Backup metatuning Re: Oil Crisis and Nuclear fusion

Hi there,

I wonder if anyone else saw the article in last week's New Scientist
about nuclear fusion (as one of the Big Projects).

I knew about the next international fusion reactor but had no idea
until reading this article that it will actually not only break
even but actually produce power - four times as much output as
is used to run it.

Unfortunately it is delayed a year or so because the international
partners can't agree where to build it - whether in France or Japan.

For those that don't know - nuclear fusion is a "clean" version of
nuclear power.

It uses radioactive fuel - tritium - but rather than create
more radioactivity as the result of the reaction, it acutally burns it
into helium which isn't radioactive. So the main problem involves preventing the fuel
from leaking from its containers - the fuel itself is generated
from lithium, and as the other part of its fuel, it needs
deuterium, which you can get from sea water:

http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/fusion.html#c5

The other radioactivity problem involves the casing of the reactor
itself and components that are close to the reaction - they
can become radioactive. But whether they do depends on what
they are made of so that can be controlled by making the
housing of materials that don't get very radioactive when
they are irradiated, or that only convert into radioactive
materials with short half lives.

Then, there is no problem with nuclear proliferation as nuclear
fusion technology can't be used to make plutonium or atomic
bombs. Nor can the fusion reactor explode - it runs in a vacuum
and the problem is to maintain that vacuum and to maintain
the magnetic fields to contain the plasma - which has to
be heated up to many times the temperature at the center
of the sun before it can produce any power. If anything
goes wrong then the plasma simply dissipates
and the reactor stops producing power - there is very little
actual matter in the plasma at any time - or if the
vacuum gets compromised, again it just stops producing
power. It can't explode like a nuclear fission reactor
and there are no moderating rods - rather the problem
is to keep it contained enough to fuse at all and if
anything goes wrong it just fizzles out.

So, no worries about terrorists or accidents.
No greenhouse gases. The main fuel is in plentiful
supply from the sea, and tritium can be generated
from Lithium which isn't that rare. No long lived
radioactive waste to deal with. Only the problems of
leaking tritium from the fuel tanks, and of
the reactor building itself becoming radioactive
need to be addressed, and with careful work they
can be made small. Tritium, though radioactive
enough to require care, isn't highly radioactive
in the way that uranium or plutonium are.
It has a very short half life so if some of it escapes
it won't linger long.

An interesting possibility is that once large fusion power
stations can be built, it is possible that
the insights could be used to build much
smaller ones later - as confinement may well be easier
if the reactor is smaller, once one has a better
idea of what is needed to achieve it.

It really looks as though it may not be so many
years away now. There have been many ups and downs.
Originally in the middle of the twentieth century
scientiest were very optimistic and thought it would
only require a few years of research to make nuclear
fission a reality. Then, just maybe ten years ago they
were thinking it looked almost hopeless becaue
it was so difficult to contain the plasma
magnetically at the very high temperatures
needed. The magnetic confinement of the plasmas
kept leaking whatever they tried.
The thing there is that the plasma
is so hot that no ordinary material can contain it,
only a magnetic field - and the charged plasma itself
will distort the field so it is quite a complicated
situation.

But then there were some breakthroughs
in methods of containing the plasma at the
end of the last century and as a result
it became much more hopeful, I knew that
through reading the popular science journals, but
hadn't realised how far they had got - now
apparently the next prototype will actually
generate power - practical fusion reactors
can't be so very far in the future after that.
Looks like it might well be finally developed
and become practical at about the same time that
oil becomes very scarce (with some luck).

It might be the thing that takes us
from a world depending on fossil fuel
to one using renewables - well fusion power
isn't quite renewable but about close to it,
and will surely be far better for us
than relying on nuclear fission power.

Robert

Re: Oil Crisis and Nuclear fusion

🔗Robert Walker <robertwalker@...>

🔗Dante Rosati <dante@...>