[ RadSafe ] Shipment of an instrument with small quantity of uranium enriched to 50% in U-235.

James Lynch jelynch at stny.rr.com
Wed Sep 29 20:39:41 CDT 2010

  DOT shipment of instrument containing radionuclide


I am questing insight into the A1 and A2 values for shipping an 
instrument which contains a small amount of enriched uranium [normal 
form]. The uranium enrichment is 50% in U-235 (a few hundred micrograms).

49CFR173.434 Activity-mass relationships for uranium and natural 
thorium. Various enrichments of Uranium in U-235 are listed, up to 95% 

49CFR173.425 is Table 4: Table of activity limits---excepted quantities 
and articles. Fractional multiples of A1 or A2.

49CFR173.435 Table of A1 and A2 values for various radionuclides. This 
table does not address Uranium enriched in U-235 greater than 20%.

My question is: how are the A1 and A2 values determined for Uranium 
enriched to 50%? Would they have to be calculated per methodology in 

Please copy jqpublic62 at hotmail.com on responses.


ASIDE: In the late 1990's the A1 and A2 values for enriched uranium (> 
20%) was included in Table 49CFR173.435. This > 20% enriched entry is 
not in the current 49CFR173.435 table (seems to have been deleted in 2004).

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