Re: Cassini Mission and Plutonium RTG's

[Bernard L Cohen <blc+@pitt.edu>]

On Wed, 27 Aug 1997, Otto G. Raabe wrote:

> Perkins and Thomas ("Worldwide Fallout", pp 53-82, TRANSURANIUM ELEMENTS IN
> THE ENVIRONMENT, W.C. Hanson, Ed. DOE/TIC-22800, 1980) have compiled a list
> of all U.S., French, U.K. USSR, and Chinese nuclear tests and releases up
> to 1980, and conclude: "Since the first nuclear weapons test at Alamogordo,
> N. Mex., on July 16, 1945, approximately 360,000 Ci of 239,240Pu has been
> injected into the atmosphere. In addition, 17,000 Ci of 238Pu entered the
> atmosphere in April 1964 as a result of the high-altitude burnup of a
> SNAP-9 satellite power source."
> 
> Maybe you can answer your question by comparing your calculation with the
> data provided by Perkins and Thomas (1980).

	--Apparently my problem was in assuming that more than half of the
fission yield came from plutonium; The numbers you quote imply that only
about 6% of the fission yield was from Pu and 94% was from Uranium. I am
surprised at this;  as the old saying goes, "you learn something new every
day".