On 08/03/2017 13:15, newshound wrote:
On 3/8/2017 2:22 AM, The Natural Philosopher wrote:
On 08/03/17 01:59, Johnny B Good wrote:
On Tue, 07 Mar 2017 14:28:29 +0000, Nick wrote:

On 07/03/2017 13:52, The Natural Philosopher wrote:
On 07/03/17 13:32, Nick wrote:
Long term solutions for energy seem to require either the fabled
fusion or new breeder reactors.


Depends how long is long.

Right now spoiled for choice. U235 or plutonium are both fairly
plentiful and will both run non-breeders and there is so much U238 and
thorium its unlikely to run out in 10,000 years even if we never get
fusion working


Once it is over a few hundred years it is effectively infinite, a
problem for future generations. Who knows what technology will be like
in 200 years?


AIUI breeder reactors will potentially produce far less waste and
much
of the current waste is potentially usable fuel. We appear to have
enough Uranium and Thorium for thousands of years. Unlike fusion
technology the engineering of such reactors appears to be relatively
achievable at what will probably be a reasonable cost.

Breeders produce just as much waste in the end But tehy can burn some
of it


I also thought they tended to burn the most obnoxious waste.


Fusion on the other hand seems to be tremendously complex, if even
achievable, and hence likely to be very expensive. So what is the
point of massive funding for ITER as opposed to funding more
achievable fission designs.

Fusions is dead simple,. Build box, light sun in it.

Its just the building of the box...


Yep but the essence of my thought was even if they can build the box it
is still likely to be expensive. Hence fission will still be cheaper.
It's like even if they get to the mountain top they will just think
well
what was the point?

I'm always a bit shocked that fission reactors aren't currently
cheaper.
I find it hard to believe that economies of scale can't bring fission
prices close to coal prices.

MSR technology (aka LFTR) is the way to go if you want a nuclear
fission
based solution safe enough to be usable as an upgrade to existing coal
fired power stations.

That is the current myth: The reality is that in many ways LFTR is more
dangerous than current GENIII/GENIV reactors. And generates uglier waste
too.


Just to get it approved is probably 15-20 years let alone building a
reactor.


+1. If it is so wonderful, why are there no serious commercial plants
operating more than 50 years after the first prototypes were built.
Bradwell was operating commercially only six years after the start of
Calder Hall.

https://en.wikipedia.org/wiki/Molten_salt_reactor

There are a lot of reasons.

1) Nuclear innovation stalled after three mile island and pretty much
stopped after Chernobyl.

2) Alternatives technologies were prioritized, e.g. Liquid Metal.

3) Less concern over long lived actinide waste

4) Uranium fuel was so cheap there was no need for breeder technology.

5) Less safety concern over high pressure systems.

6) Less concern over carbon emissions.

The point is the world has changed and different requirements may make
them more desirable now. I think it is probably worth investigating them.