Nunn May

[FRAMEP@ORAU.GOV]

Better late than never:

Some time ago, a question was raised about the identity of the 
radioactive material sent by the spy Alan Nunn May to the Soviets.
Specifically the question was "Was it plutonium or U-233'

Quoting Bertrand Goldschmidt in his book Atomic Rivals (1990 Rutgers
Univ Press)  May "had furnished a plutonium capsule containing 160
micrograms of U-233 to a Soviet agent on August 9, and another member
of the embassy had immediately taken it to Moscow by plane" 
Goldschmidt had isolated the original sample of U-233 from which the
160 micrograms was taken.

The book Klaus Fuchs Atom Spy by Robert C Williams (Harvard
University Press 1987) states that it was U-233, and if I remember
correctly, U-235 as well.  Williams cites an official government report that
might have the specifics.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov