No subject

politicians & public.
Adding reprocessing would probably make the job twice as tough.

I also think its important not to forget the significant challenges of
handling, dismantling and re-fabricating SNF robotically, whilst maintaining
cooling throughout the process (presumably submerged in a pool of sodium).

We usually hear only about the electro-reprocessing facilities, but there
must be more to it than that.

For example, look at the robotic infrastructure for handling irradiated fuel
in reactors where on-line refuelling is performed, such as in Candu
reactors.
The robotic fuelling machines are some of the most expensive pieces of
equipment in the plant ! .....and all they do, is just move fuel bundles
around: no disassembly, chopping up, conversion to fluoride salts,
electro-refining, re-conversion to metal and later re-casting and
re-fabricating the fuel elements.

Defective fueling machines have in the past put Candu plants out of action
for extended periods, while the robotic mechanisms are repaired.
With so little information about IFR/PRISM available publicly, we can only
speculate what sort of problems a more complex robotic system, working in a
pool of opaque, flammable sodium coolant could cause (the fueling machines
are continuously cooled, as the radioactive fuel inside generates a lot of
heat).

In the book "Plentiful Energy - The story of the Integral Fast Reactor"
(http://bravenewclimate.com/2012/02/19/ifr-fad-10/ ) it is claimed that
"spent metal fuel can be processed with much cheaper techniques" than oxide
SNF.
That isn't really saying much !
What fraction of plutonium and other TRUs slip through the processing & into
the waste stream ?
...at what cost, for each factor-of-ten improvement ?
And if we don't care that much about the waste stream, then why bother
reprocessing at all ?

Evidently, that is the intent for the UK bid.

Wouldn't it be better to limit the fuel processing to a simple
"melt-refining" that just removes the fuel-damaging, neutron-absorbing
volatile fission products ?
According to TerraPower (the Bill Gates outfit), periodic melt refining in
their TWR reactor allows burn-ups exceeding 50% to be achieved.
If the "melt-refining" is carried out in recycled fuel rod tubes (ie. no
chopping up, fluoride conversion, electro-refining & re-fabrication), then
the reprocessing plant essentially disappears.
(See http://lumma.org/temp/Ellis_et_al-TWRs_A_Truly_Sustainable_Resource.pdf
)


 Jaro
^^^^^^^^^^^^^^^^^^^^^^^^^



-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of George Stanford
Sent: July-02-12 1:13 AM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] [NucNews] Which nuclear technology has future?

Dear  Dr. Parthasarathy:

      Thanks for your note.  It raises some interesting thoughts.  I
intersperse some comments below.
.
At 10:06 PM 7/1/2012, parthasarathy k s wrote:
>Dear Dr Stanford,
>
>Who will spend money for the developmental efforts? Uranium is cheaply 
>available. LWR is not certainly the best; but it is readily available. 
>Funding for R & D on newer technologies will have to come from the 
>Government. I recall your comments that IFR technology is more 
>completely developed compared to the breeders.
.
GSS:  (a) Actually, the IFR IS a breeder -- or  else a net burner of Pu, or
an "isobreeder," depending on its loading.

<SNIP>