Radiological Safety Training for Uranium Facilities
Module 101 - Properties of Uranium
An unwanted byprodu ct of 233U
production in a breeder reactor. Due
to its much shorter half-life, 232U
contributes most of the radioactivity
in samples of 233U.
Manufactured by irrad iating 232Th
1.6 x 10 5 y
with neutrons. It is a criticality
hazard because it is fissile.
U. It is
A decay product of
concentrated with 235U during
enrichment. Highly enriched uranium
2.5 x 105 y
contains about 1% 234U. Most of the
radioactivity of enriched uranium is
from the 234U.
Fissile with slow neutrons; therefore,
it is of primary interest for reactors
7.1 x 108 y
and weap ons. If not ha ndled safely,
an accumulation of
Some 235U is converted to 236U in
2.3 x 107 y
reactors. It is also present in
reprocessed reactor fuel.
The most abundant uranium isotope.
It is fissionable with fast neutrons;
4.5 x 109 y
however, it is not fissile (i.e., with
thermal neutrons) so it is not a
As uranium goes through radioactive decay, it produces other radioactive elements known as
radioactive decay products (also called progeny or daughter products). These radioactive decay
products are also radioactive and have to be taken into account for radiological protection purposes.