Atmospheric plutonium

[Gary Schroeder <schroede@mail.sep.bnl.gov>]

>Thanks for the comments of Marvin Goldman and Steven Frey. Now it is
>confirmed that Pu-238 was spread in large quantities at earlier reentries
>and we know that nobody was killed. Is it not possible to communicate this
>to the mass media and to the persons who claim disastrous effects for the
>case of burnup in the atmosphere? 

I think it's importnat to point out that no one can really make this
statement and back it up.  If excees cancers were to be induced by airborne
plutoinum, how would you know?  Any excess cancers produced by such a
source (if they exist) are likely to be statistically undetectable.

Other nuclear reentries of interest:

1.  On April 21, 1964, a US satellite which failed to achieve orbit
reentered the atmosphere carrying a 17,000 Ci Pu-238 source (SNAP-9A).
Four months later, Pu-238 above levels attributable to weapons testing was
detected in the stratosphere.  By 1970, about 16,000 Ci was estimated to
have been deposited at ground level.  UNSCEAR (1993) estimated the
world-wide individual EDE from this source to be 0.04 microrem and the
collective EDE to be 240 person-rem.

2.  Soviet satellite Cosmos 954 rentered the atmosphere over Canada on
January 24, 1978.  The core is believed to have contained 20 kg of highly
enriched uranium with 84 Ci of Sr-90, 4,900 Ci of I-131 and 86 Ci of
Cs-137.  Debris with dose rates as high as 500 rem/hr were found.   4,000
particles ranging in size from 0.1 to 1.0 mm were recovered, but it is
estimated that only 0.1% of the dispersed particles were found.  This was
obviously worse than SNAP-9A since Cosmos 954 was carrying what appears to
be an actual small reactor, not a relatively benign radioisotope thermal
generator (RTG).

If I remeber correctly, the Apollo 13 SNAP generator was recovered intact
from the ocean floor.  If wrong, I'm sure someone will correct me. 


=======================
Gary L. Schroeder
Brookhaven National Laboratory
Environmental Protection Office
gs1@bnl.gov