Environmental Engineering Reference
In-Depth Information
Alpha particle
a
Beta particle
b
Gamma ray
g
Figure 8.1
Types of radiation and shielding (Fentiman 2008)
LWR Fuel
Fabrication
Ore
Enrichment
LWRs
Used fuel
thrown away
Used fuel
to recycle
Residual
wastes
Separations
Geologic
Repository
ABRs
ABR Fuel
Fabrication
Figure 8.2
Open and closed fuel cycles (Courtesy of the Department of Energy) (USDOE
Office of Nuclear Energy 2008)
If the used nuclear fuel is buried, the fuel cycle is said to be open, but if the
used nuclear fuel is reprocessed and recycled, the fuel cycle is said to be closed.
Figure 8.2 shows the nuclear fuel cycle. A short description of the steps in the
fuel cycle will help the reader to understand the nature of the used nuclear fuel
that will be transported to the repository or the reprocessing facility.
On average, uranium is found in concentrations of 2.8 parts per million in
the earth's crust (World Nuclear Association 2008). However, like most metals,
uranium is found in rich deposits in some locations. The countries with the largest
known recoverable uranium resources are shown in Table 8.1.
Search WWH ::
Custom Search