[ RadSafe ] Fractionation of Uranium Isotopes in Nature

[Leo M. Lowe]

Further to the recent discussions on the chemistry of natural uranium, DU 
or enriched uranium, the fractionation of uranium isotopes does occur in 
nature.  For example, despite the equal radioactivity concentrations of 
U-238 and U-234 in rocks and soils, the U-234/U-238 ratio in groundwater 
generally unity, and can reach values of 10 or more.  The US EPA drinking 
water guidelines use a U-234/U-238 ratio of 1.3 when converting between 
mass and activity concentrations of uranium in water.

Of course, this should not be taken to imply that the chemistry or 
biokinetics of natural uranium, DU  and enriched uranium differ 
significantly when discussing the potential non-radiological health impacts 
of uranium.

Regards,
Leo M. Lowe, Ph.D., P.Phys.

SENES Consultants Limited
llowe at senes.ca
www.senes.ca
Tel: (905) 764-9380
Fax:(905) 764-9386

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