Re: Question About Historical Criticality Accident

["Michael C. Baker" <mcbaker@lanl.gov>]

The Nuclear Criticality Information report (DOE/NCT-04, March 
1989)  contains a revised version of "A Review of Criticality Accidents" 
(TID-4500).  In that revised report it lists three early criticality 
accidents as follows:

June 6, 1945 - pseudosphere of uranium cubes, water reflected, local control

August 21, 1945 - plutonium core reflected with tungsten carbide, hand assembly

May 21, 1945 - plutonium core reflected with beryllium, hand assembly

I also checked the original document TID-4500 and it lists the same 
dates.  Also, in the criticality safety training here at Los Alamos I seem 
to recall that the accident in question occurred shortly after the dropping 
of both bombs which would agree with the August 21st date.  For more 
information or guidance to another reference, you might try contacting 
Thomas McLaughlin who is the group leader for criticality safety at Los 
Alamos. His email is tpm@lanl.gov.  If he doesn't know the answer to your 
question he can probably provide you with a contact to a person who does.

Mike

______________________________________________

Michael C. Baker, Ph.D., P.E.
Environmental Technology Group
Environmental Science & Waste Technology Division
Los Alamos National Laboratory
Mail Stop J594, Los Alamos, NM 87545

mcbaker@lanl.gov

(505) 667-7334 (phone)
(505) 665-8346 (fax)
(505) 996-3519 (pager)
______________________________________________

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