alt.energy.renewable

"T. Keating" wrote in message
news:ap9qu35dob3glf0m0b9l9clmdn9sfmt9ub@4ax.com...
> On Fri, 28 Mar 2008 09:47:28 -0700 (PDT), "calderhome@yahoo.com"
> wrote:
>
>>
>>
>>http://ukpress.google.com/article/ALeqM5hwwiUVDzBZM0GHevZ13mLxx_VyYQ
>>- - - - -
>>SEE
>>
>

>
> Breeders to extend the fuel supply are still in the experimental stage
> and lack many significant safety features (required to increase
> breeding ratio).

Bah!! What safety system, when eliminated, increases breeding ratio? True,
some breeders are more difficult to control due to a different
delayed-neutron coefficient, but that's not a 'safety system'. There is no
inherenent reason to eliminate *any* safety system to "increase breeding
ratio", you're just making sh__ up to scare people.

>
> Japan's prototype breeder (MonJu ~100MW) was shutdown after a
> liquid metal coolant leak after just 5 months of operation..
>
> The US's Fermi-1 breeder reactor suffered a partial core meltdown
> after just three years of operation. Basis for the Book titled
> "We Almost Lost Detroit"
>

The partial core meltdown at Fermi-1 had *nothing* to do with it being a
breeder and you probably know that. If you actually read the book, you'd
know it was a blockage in a few (or was it only one??) coolant channel
caused by a device breaking free from the bottom of the reactor vessel.
This device breaking off was not inherent to it being a breeder, it was
designed to separate some of the 'corium' should there be a complete
meltdown. It is ironic that a safety device *added to the reactor vessel*
to mitigate the effects of a core meltdown actually *caused* a partial
meltdown.

> ====
>
> As for gas cooled.. pebble bed..
> they're much smaller plants(100 to 300 MW range) , still in
> prototype research stage after several accidents, and a containment
> failure.
>
> http://www.greenparty.org.za/capetowngreens/nuclear/PBMRFactSheet.pdf
> "Fission chips: What they don't tell you
> about the Pebble-Bed Modular Reactor (PBMR)"
>

Another mis-direction. Did you read the article? It is obviously biased.
There has been *one* minor release of radioactivity from a PBMR (the one in
Germany). It was very unfortunate that the operators did not go public with
the information sooner and was thus white-washed as a cover-up. But the
truth is the amount of radioactivity released was quite low and did not
present a danger to the public.

Got a cite for your 'several accidents'?

The PBMR has some very good intrinsic safety features that you obviously
don't want to talk about. Like have it operate at full power and shut off
all the coolant flow and there is no fuel overheating or fuel failure, even
after a couple of days of no active cooling. Or the fact that there is very
little excess reactivity in a PBR because it is being constantly refueled
and needs no excess reactivity to operate. Or the fact that it operates
under lower pressures than LWRs and is thus less likely to develop a leak.
Or that the amount of energy stored in the coolant is much lower, making a
leak much easier to contain.

But I know you and your typical response. So I'm only posting this so
others can read something about PBMR's that isn't so obviously biased.

daestrom