Dave Liquorice wrote:
On 22 Mar 2011 12:00:03 GMT, John Stumbles
wrote:

http://www.telegraph.co.uk/finance/c...pritchard/8393
984/Safe-nuclear-does-exist-and-China-is-leading-the-way-with-thorium.
html

Good to see something in a mainstream newspaper. And not a complete load
of ********

It is an interesting article, and shows the influence of goverments
and big business has on the development of new ideas or processes
that don't fit in with the agendas of either.

I don't understand this bit though:

"Professor Robert Cywinksi from Huddersfield University said thorium
must be bombarded with neutrons to drive the fission process. "There
is no chain reaction. Fission dies the moment you switch off the
photon beam. There are not enough neutrons for it continue of its own
accord," he said."

Since when have photons been neutrons?

OK, Now I am Not a Nuclear Physicist BUT what I think happens is that
high energy gamma rays - photons - or maybe its electrons or protons
alpha particles - bash into thorium. It is stable BUT if you smash it
hard enough you get slightly more out than you put in, and a few
neutrons too.

These an then be used to smash into other crap lying around - depleted
uranium works I think, and when that goes pop, it fission decays into a
smaller one if you hit it hard enough, with a net release of energy and
the heavier it is, the easier it is, up to uranium-235 which is the
heaviest naturally ocurring element. The rest we make.

Likewise in principle any element lighter than iron can be fusioned, to
make a heavier one and that also gives of energy. Iron is the most
nuclear stable of the lot.

Only uranium-235 as a natural element is capable of natural chain
reactions. The heavier stuff has decayed..

(Ok radon which is as by product of uranium decay is also around, but
only becasue teh uranim is)


BUT stuff that's nearly as heavy as uranium or uranium 238 (ordinary
depleted ****) will split quite easily IF you give it enough excess
energy, and then you do ALMOST get a chain reaction. Its like trying to
burn anthracite on a bonfire, with a bellows it works, but mostly it
goes out.

There's a lot more to it than that..moderators and coatings and stuff,
but in principle it's megawatts in, gigawatts out, and if the megawatts
fail the gigawatts stop almost instantly.

I'd say there would still be some decay products, just not as many.

Oddly enough, in a way its like fusion, in that you have to throw a lot
of energy at it to get it going, but unlike fusion you don't need the
immense pressures nor do o have the mmense temperatures sither.

here's what wiki says/ Protobns, not photons.

The energy amplifier uses a synchrotron or other appropriate accelerator
(e.g. cyclotron, fixed-field alternating-gradient) to produce a beam of
protons. These hit a heavy metal target such as lead, thorium or uranium
and produce neutrons through the process of spallation. It might be
possible to increase the neutron flux through the use of a neutron
amplifier, a thin film of fissile material surrounding the spallation
source; the use of neutron amplification in CANDU reactors has been
proposed. While CANDU is a critical design, many of the concepts can be
applied to a sub-critical system.[1][2] Thorium nuclei absorb neutrons,
thus breeding fissile uranium-233, an isotope of uranium which is not
found in nature. Moderated neutrons produce U-233 fission, releasing energy.

This design is entirely plausible with currently available technology,
but requires more study before it can be declared both practical and
economical.


(from the little I know about the subject)

I know sod all, which is probably why I don't understand the above
quote.