U-234 mention in the paper

They attempted to control it by lowering cubes of uranium on
chains into the heavy water, had they achieved criticallity it
would have killed everyone in the immediate area.

Right Keith but problem is that some Germans were already using graphite as
moderator.

"Denyav" wrote in message
...
I rather doubt they ever seized any such thing, the heavy water used
in research at Hamburg came from Verwork and I KNOW that
heavy water isnt necessary to enrich uranium or build a working
reactor.

Yes,if you start using graphite as moderator you dont need heavy water
anymore.

Nobody, I happen to know the some of those who developed
the centrifuge technology for BNFL (now Urenco) in the 60's and 70's

Prior to that they, like the Soviets and Americans used gaseous diffusion
The first US centrifuge system went live at Piketon Ohio in the 1980's

If we examine the Soviet plants we see

Angarsk Electrolytic Chemical Combine (AEKhK)
1957, 308 gas diffusion machines

ELECTROCHEMICAL PLANT (EKhZ)
aka Kranoyarsk-45 decommisioned its
gaseous diffusion plant in 1990

Urals Electrochemical Combine (UEKhK)
began producing highly enriched uranium (HEU) in 1949
using the gaseous diffusion process

Siberian Chemical Combine (SKhK)
aka Tomsk-7 established in 1949, and began producing highly enriched
uranium (HEU) for the Soviet nuclear weapons program in 1953.
using the gaseous diffusion process


The centrifuge process requires both precision engineering and
some rather exotic alloys as the feed stock, uranium hexafluoride
is amazing corrosive. The Germans lacked the basic alloys necessary
which critically affected their enrichment programmes in the same
way it delayed their jet engine pogramme.

The father of modern gas cenrifuges is Dr.Zippe,he is the one who
developed
german cetrifuges for Kammlers SS advanced weapons research.
After war he was jailed and taken to USSR,soviets asked him to build a
centrifuge with 10% efficiency (regarded as a very good value during that
time
by both Soviets and Americans) but he came up with a design with
asthonishing
(for that time) efficieny almost 30% .(needless to say this design

Pure fantasy

The best efficiency for a single centrifuge is VERY much smaller
than 30%, thats why they build trains of dozens of the damm things

was a
slightly improved version of Kammlers centrifuges).
Soviets etremely impressed by his work offered him a monetary award and a
free
ticket home.
In 50s Dr.Zippe came to US and took a faculty position at Virginia Tech,I
am
sure the quality of US centrifuge designers he helped to train would say
something about the quality of this centrifuge pioneering talent.


They would , they'd say he never designed a single one since all
US enrichment plants until 1981 were the gaseous diffusion type

http://www.nrc.gov/materials/fuel-cycle-fac/faq.html

Keith

The best efficiency for a single centrifuge is VERY much smaller
than 30%, thats why they build trains of dozens of the damm things


Thats because of seperation factor which is around 1,05.

They would , they'd say he never designed a single one since all
US enrichment plants until 1981 were the gaseous diffusion type


Thats correct and proves my point ,before arrival of Zippe at Virginia,US was a
backward country as far as gas centrifuge technology concerned and to correct
this situation US scientists launched a campaign to bring Zippe to US as
development helper.Only after Zippe's arrival,US recognized the importance of
centrifuge technology for the production of nuclear weapons,as a consequense of
this late recognization US pressurized (West) German goverment to classify ALL
centrifuge research made in (West) Germany.West German government bowed to US
pressure and classifed ALL German centrifuge research on August 1,1960,needless
to say many of classified research was conducted by Zippe.
(I always wondered why US classifies so many scientific documents,to protect
advanced US technology or to protect much more advanced foreign technology?)