Bear with me now, I have to work through a few concepts.

Around 1939, following the culmination of the above developments, physicists Leo Szilard, Edward Teller, and Eugene Wigner urged Einstein to write to Franklin D. Roosevelt, the then president of the US about the possibility that the Germans, then in conflict with the US, would be attempting to build and use a uranium-based weapon. 

The left is more than one page and has been preserved in the Franklin D. Roosevelt Presidential Library.

The Einstein Letter (click here) 

Below is Albert Einstein's desk on the day he died. (click here)

Before there was an atomic bomb here had to be enriched uranium. The project to build an atomic weapon with unknown capacity began in 1939 and it was called "The Manhattan Project." (click here)

Remember I asked a question of any Presidential Candidate to what U-235 was, etc. Well, here it is. Not difficult to find. Now, the 'isotope' concept is rather interesting to understand.

KINDLY remember, the war/defense department of any country with modern day weapons is not possible without science.

Making Enriched Uranium (click here) 

The most complicated issue to be addressed in making of an atomic bomb was the production of ample amounts of "enriched" uranium to sustain a chain reaction. At the time, uranium-235 was very hard to extract. In fact, the ratio of conversion from uranium ore to uranium metal is 500:1. 

Compounding this, the one part of uranium that is finally refined from the ore is over 99% uranium-238, which is practically useless for an atomic bomb. To make the task even more difficult, the useful U-235 and nearly useless U-238 are isotopes, nearly identical in their chemical makeup. 

No ordinary chemical extraction method could separate them; only mechanical methods could work.

A massive enrichment laboratory/plant was constructed at Oak Ridge, Tennessee (click here). Harold Urey and his colleagues at Columbia University devised an extraction system that worked on the principle of gaseous diffusion, and Ernest Lawrence (inventor of the Cyclotron) at the University of California in Berkeley implemented a process involving magnetic separation of the two isotopes.

Next, a gas centrifuge was used to further separate the lighter U-235 from the heavier, non-fissionable U-238. Once all of these procedures had been completed, all that needed to be done was to put to the test the entire concept behind atomic fission ("splitting the atom," in layman's terms).

The process of extracting U-235 is a grossly wasteful process. The current places of uranium enrichment are Germany, the Netherlands, the UK and the USA.

URENCO operates plants in Germany, the Netherlands, (click here) the UK and the US, using URENCO's world-leading centrifuge technology to enrich uranium for the use as a nuclear fuel for civil power generation. URENCO's focus is on providing safe, cost effective and reliable.

 

uranium enrichment services within a framework of environmental, social and corporate responsibility. Our goal is to further increase worldwide market share and to become the leading supplier in the extended global enrichment market.

I am sure they have exceptionally tight security, right?