Re: I'm hearing bad things about breeder reactors

From: Eunometic (eunometic_at_yahoo.com.au)
Date: 06/10/04 

Date: Thu, 10 Jun 2004 13:23:46 GMT

"brianb" <bri1600bv@hotmail.com> wrote in message
news:68a6629.0406090711.701863fd@posting.google.com...
> eunometic@yahoo.com.au (Eunometic) wrote in message
news:<e935396a.0406081726.2b818661@posting.google.com>...
> > bri1600bv@hotmail.com (brianb) wrote in message
news:<68a6629.0406080759.931460d@posting.google.com>...
> > > They're saying that they could never work out the kinks and that
they
> > > are incredibly expensive etc.
> > >
> > > Are breeder reactors in general more expensive than non
breeders, if
> > > they CAN work out the kinks?
> > >
> > > Does anyone know what the current status of research and such
is?
> > >
> > > Is it only breeder reactors that can burn plutonium? Or is the
idea
> > > that by turning U238 into plutonium in a breeder that this
plutonium
> > > can be burned elsewhere? I guess I'm confused about the
difference
> > > between "breeder reactor" and "reprocessing". Anyone know?
Thanks in
> > > advance.
> >
> > All of the breeder programes were cut short of their full
development
> > and test cycle as instigated. The IFR for instance was cut down
by
> > Jimmy Carter of political reasons not technical or economic ones.
The
> > Japanese even offered to continue funding the research. The IFR
was
> > very proliferation resistent becuase the pyro-processing can't
produce
> > pure plutonium and never left the reator building however the fear
was
> > that such reactors would ultimetly spread the abillity of other
> > countries to produce bombs.
> >
> > Yes there concerns relating to corrosion reistence of materials
but
> > saying that there are problems that need to be solved is not the
same
> > as saying that those problems are difficult to solve. For
instance
> > you can't test the corrosion resistence of various alloys and
> > materials unless you actualy have a program to test them by
exposure
> > to real conditions.
> >
> > The IFR (integral Fuel Reactor) was fueled with a mixture of
enriched
> > uranium. Over its life the U235 would be fissioned for energy
while
> > the U238 would convert into Plutonium at a rate faster than U235
was
> > used up. The fuel would occaisionaly be partialy removed and
> > 'pyro-processed' in the reactor building itself (eliminating a
> > security issue) and returned to the reactor. As a result the IFR
only
> > needed one fueling in its entire life. During pyroprocessing the
> > 'actinides' were removed and returned to the reactor in a seperate
> > part where their decay would provide energy and where high flux
> > neutrons would destroy the actinides.
> >
> > Becuase the actinieds were destroyed by 'transmutation' the IFR
did
> > not produce long term waste. IE the volume and activity of waste
is
> > drasticaly reduced.
> >
> > Becuase the IFR needed such little fuel and even produced more
than it
> > used the japanese calculated that they could absorb all the
uranium
> > they needed into special polymer membranse suspended in the sea.
> > While the Uranium would be expensice the price of electricity
would be
> > hardly effected. They calculated that this would given mankind
> > millions of years of energy.
> >
> > The French reactor 'super phenix' had some problems with tube
welds
> > and has only been opperated small amount of time. It was
restarted
> > recently for some transmutation experiments. The IFR can never
have
> > that problem becuase it has the fuel in tubes suspended in to
molten
> > sodium pool rather than the other way around.
>
> Thanks for your reply. Did the IFR ever get to a point where it
could
> be made for commercial use? I know they had a plant in Idaho, I
read
> an interview with the guy in charge. I think Clinton finally put
the
> nail in the coffin.

I believe it got close. You need to build test plants and after that
pilot plants. There are a lot of practical things to learn. The
Molten Salt reactor also got close but it had corrosion problems. A
lot of the issues relate to the reactors breeding but not breeding
enough but overall the consensus is that these reactors are very
feasible.

There are VHTGR (Very Hight Temperature Gas Reactors) that are
breeders. One of the more intersting cycles is the molten lead
breeder. They can be built up to any size but if kept down to below
200MW they can be be built as a self contained capsule that is sealed
at the factory. The complete unit is shipped and then runs for 20
year with no intervention completely on passive cooling. It is then
switched of for a while and shipped back to the factory for disposal.
the Russians have a lead bismuth one. A chap called Greenspan is
trying to build one in the USA. Then there are the thermal breeders
that don't need fast neutrons. There are neutron beam pumped
breeders.

There is quite literaly dozens of viable ways of building breeders.
almost to many to choose from.

>
> Anyway, I find this field fascinating. What is your academic
> background? Are you currently a nuclear engineer?

I am a professional electrical engineer. Mainly involved in
Automation and that put me into high availability fault tolerant
control systems that are applied in critical plant like nuclear
reactors. Energy is more of a personal and political interest for
me.

> You and the other
> responders have alot of knowledge. I almost feel like going back to
> school and majoring in Nuclear Engineering...I have a math
background
> and did well in Physics but I'd obviously have alot to learn.

alt.engineering.nuclear used to have some interesting boys and girls.
You might go through google there. At some point I expect a great
many people will need to work in the nuclear industry.