The FuTure oF nuclear Fuel cycle - MIT Energy Initiative

tricity costs. Waste management costs are slightly over 10% of fuel cycle costs and thus
between 1 and 2% of electricity costs. Several observations follow from such analysis.
• Fuel cycle decisions that do not impact the choice of the reactor have small impacts on the
cost of electricity. If it is desired to recycle SNF into LWRs for any reason or use a somewhat
more expensive disposal option for SNF, the relative cost impacts are small.
• If one chooses an alternative fuel cycle that requires a different type of reactor, the capital
cost of that reactor compared to an LWR will likely dominate the relative economics of the
two options.
• High reactor capital costs favor fuel cycles that use reactors with the lowest capital costs.
Today LWRs have the lowest capital costs and the once-through fuel cycle is the economically
preferred option. There have been proposals to develop LWRs with different
types of reactor cores and fuel cycles—including hard-spectrum reactor cores and
reactor cores to burn transuranics (plutonium, etc.). Presumably these modified LWRs
would have capital costs similar to traditional LWRs. If an alternative fuel cycle is desired
for any reason, economics will favor modifying the most economic existing reactor types
to meet those goals if that is technically viable and meets all safety requirements.
• If a new reactor type is demonstrated to be more economic than an LWR, it may drive many
fuel cycle decisions.
Fuel CyCle ChoiCeS
In the history of commercial nuclear power, three main fuel cycles have been developed:
the open fuel cycle used today in the U.S., a partly closed fuel cycle used today in countries
such as France, and a specific fast reactor fuel cycle that has been demonstrated but not deployed.
These options are analyzed in this report to provide an understanding of fuel cycles
in general.
The historical development of the commercial fuel cycle (Sidebar) was characterized by the
commercial deployment of LWRs and the belief, based on the information then available,
that uranium resources were extremely limited. Because of the relatively inefficient use of
uranium by LWRs, uranium would become expensive and economically limit the use of
nuclear energy. This led by the late 1960s to a single fuel cycle vision (Fig. 2.2) for the future.
• The first generation commercial reactors were to be light-water reactors (LWRs)—based
partly on what had been learned from the navy nuclear propulsion program. Because
LWRs extract less than 1% of the energy value of the uranium that is mined, they would
be a transition technology to more uranium-efficient reactors.
• SNF from LWRs would be chemically processed (reprocessed) to recover uranium and
plutonium for fabrication of sodium-cooled fast reactor (SFR) fuel to startup fast reactors.
The fission product wastes from the LWR SNF would be converted into high-level
wastes (HLWs) for disposal.
• The SFR would be developed and deployed. The fast reactor SNF would be reprocessed.
The plutonium and uranium in the SNF would be combined with depleted uranium to
produce new SFR fuel assemblies.
22 MIT STudy on The FuTure oF nuclear Fuel cycle