Management of Commercially Generated Radioactive Waste - U.S. ...

3.14
We do not yet have sufficient operating experience with nuclear plants to predict this
life cycle with high confidence. These plants are generally assumed to have lifetimes in
the range of 30 to 40 years. The upper end of this range was used here to be conservative
in regard to the amount of radioactive waste to be managed for a specific system. The
declining load factor as facilities age has not yet been observed in nuclear plants but is
similar to the experience of large central-station fossil-fuel generating units.
Using the year 2000 as a reference point, the impacts of other growth assumptions can
be derived by comparison to this case. For example, a 500 GWe system in the year 2000 would
produce approximately twice the impacts of Case 3 if allowed to run out its useful life, or
a 125 GWe system in the year 2000 would produce approximately one-half as much impact.
Case 4--250 GWe in Year 2000 and Constant--This case follows the same growth pattern
as Case 3 up to the year 2000. Then, instead of phasing out capacity as plants are decom-
missioned, new capacity is added to maintain the total capacity at 250 Gwe until the
year 2040, beyond which time the case is not analyzed. A total of 316,000 MTHM of spent
fuel is produced in this case.
This case illustrates the rate at which continuous waste management requirements and
impacts would occur in a constant or steady-state system. An approximate equilibrium is
established.
Waste management requirements and impacts at other constant capacity levels can be
obtained by comparing capacities and impacts to this case.
Case 5--250 GWe in Year 2000 and 500 GWe in 2040--This case also follows the same
growth pattern as Case 3 up to the year 2000. After that, however, capacity additions con-
tinue until a doubled capacity of 500 GWe is reached in the year 2040. Beyond the
year 2040, the case is not analyzed. A total of 427,000 MTHM of spent fuel is produced in
this case.
No equilibrium is established in this case. It illustrates the waste management
requirements and impacts for a continuously expanding system. Results can be extrapolated
to other growth rates by comparing the differences between the year 2040 capacities in
Cases 4 and 5 to the difference in impacts. For example, a capacity of 750 GWe in the
year 2040 would have twice the additional impact over Case 4 that Case 5 has.
3.2.3 Resource Commitment Assessment
In most instances, data describing environmental impacts that are caused by commitments
of resources are presented as land and water requirements, material requirements, energy
consumption, and manpower requirements for construction, operation, and decommissioning of
the facilities. Resource commitments are combined by facilities on a single reference plant
basis for analyzing predisposal activities in Section 4.7 and for geologic repositories in
Section 5.4. Resource commitments are further aggregated by plant to systems of waste
management and disposal within fuel cycle options in Chapter 7.