Re: Toxic Trivia (Polonium)

[Philip Hypes <phypes@lanl.gov>]

(snip) 
>Polonium is so radioactive that a 0.50 gram sample will reach
temperatures 
>greater than 500 degrees all by itself. The radiation energy is so
great 
>that an 
>amount too small to see would be a lethal dose! 
(snip) 
> 
>Any comment on the heating of Po-210 or the toxicity rating? 
> 
> 
After calculating the specific power of Po-210, I scrolled a little
further down on the web page I was using as a reference (from the
periodic table on the web, LANL -
http://pearl1.lanl.gov/periodic/),
and read the following: 
"The energy released by its decay is so large (140W/g) that a
capsule containing about half a gram reaches a temperature above 500C.
The capsule also presents a contact gamma-ray dose rate of 0.012 Gy/h. A
few curies (1 curie = 3.7 x 1010Bq) of polonium exhibit a blue glow,
caused by excitation of the surrounding gas."

I calculated a specific power of 141.2 W/g. Just in case anyone is 
curious, the formula for specific power can be found in NUREG/CR 5550,
Passive Nondestructive Assay of Nuclear Materials. The formula is

Power (in watts) = 2119.3Qm/(T^.5)A

Where Q is the MeV/dis 
          m is the mass of
the sample 
          T^.5 is in
years
          A is the atomic
weight (mass number)

___________________________________________________________

Philip Hypes

Los Alamos National Laboratory

Safeguards Science and Technology Group (NIS 5)

(505) 667-1556  phypes@lanl.gov

Opinions expressed are purely my own unless otherwise noted