Re: german atomic bomb research


"Eunometic" <eunometic@xxxxxxxxxxxx> wrote in message
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Keith W wrote:
"Eunometic" <eunometic@xxxxxxxxxxxx> wrote in message
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Keith W wrote:
"Juergen Nieveler" <juergen.nieveler.nospam@xxxxxxxx> wrote in message
news:Xns97F185E446B91juergennieveler@xxxxxxxxxxxxxxx
"roostertail" <robertdaleroostertail@xxxxxxxxxxx> wrote:

rob : did the germans have enough nuclear material for a dirty
nuclear
bomb. If so how would they have put it together?

I'm not Rob, but Germany had enough Uranium to build a small reactor
(using cubes suspended by wires into heavy water).


Which didnt work and thus never produced any radioisotopes.

Keith


It did work and it did produce fission and radioisoptopes.


It failed to reach criticallity. The rate of fission was little higher
than
occurs in nature.

It wasn't intended to do reach criticality: it was meant to confirm
theory and provide data. In that sense it worked perfectly well. It
is the neutron multiplication factor and neutron loss that are the
critical parameters in determining criticality.


It stilll didnt work



It was a criticality experiment in a subcritical reactor. A lattice of
uranium cubes was created by suspension of the cubes from chains. The
lattice was lowered into heavy water moderator while a neutron source
was applied. The the neutron source initiated fission in the uranium
cubes and neutrons from the fission were slowed by the moderator and
then went on to produce further neutrons. The neutron multiplication
effect was about 7.

Far short of that required for an operating reactor

Actually it's not far short. A practical system would require some
form of heat extraction; some form of control rod or shielding between


And a workable design


> It wasn't a self sustaining reaction; the neutron
source was necessary.

i.e. It didnt work


If the dimensions had of been increased by 50%
the reduced surface area to volume ratio would have ensured that the
reaction was self sustaining.

And the lack of control rods and shielding would have guaranteed
the world's first reactor accident.

Nutron levels do no buildup instantly in a reactor due to the relience
on delayed release neutrons; this is what makes them controllable.


Tell that to the Chernobyl operators

An enlarged version of the lattice reactor clearly would have
incorporated some means of control. Neutron absorbers and shielding
placed between the lattice is not difficult thing to achive at all; the
lattice design lends itself well to that.

Yet the desing was not pursued post wat

Initial experiments with
graphite moderator had failed and set the program askew for several
years unitill the contamination by neutron absorbers of the supposeldly
'ultra pure' graphite was discovered. Withdrawl of the lattice from
the moderator/heavy water is completely effective in modulating or
controling the rate of reaction; it is simply not practicable in that

This must be some new definition of practical. The reactor
didnt bloody work

after many hours or days of opperation the buildup or radioisoptopes
would ensure a significant heat generation when the cubes were
withdrawn. In an criticality experiment this is not an issue.


Erm no, fast neutrons from a working reactor heat up
the containment., decay heat is a different issue




A self sustaining reaction was not
expected; the experiment protocol called for immediate withdrawl of the
uranium cubes should it start.


The reality would have been nasty, fast neutrons and gamma radiation
are not known for their health giving properties.

The experimental unit was burried and deeply recessed in the earth.
You should be able to comprehend that unless the victim was burried in
the earth along side of it or sitting right on top of the lid that he
would receive no practicable exposure.


Unless of course he was standing above the BURIED reactor.
There was no shielding on the bloody lid

Sheesh

Keith


.

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