permit substitution of nuclear power for coal if necessary, or to provide a desirable diversity of power sources.
The relative roles advanced converters and breeders might play in the energy supply sector cannot easily be predicted. Conditions that have a reasonable chance of eventuating would be favorable to the installation of both types of reactors (steady growth in electrical demand; economic attractiveness of nuclear power relative to other sources of electricity; and satisfactory resolution of the political and social issues discussed later in this chapter).
Breeders are more flexible in their ability to respond to quite rapid growth in demand as well as to rather moderate growth. Thus, although the two types of reactors both serve, in a sense, as insurance that increased supplies of electricity could be provided if needed, breeders provide broader coverage. The probability that such coverage will be needed by, say, 2010 may not be very high. However, the risk of inadequate supply could be high, and insurance is of greatest value against high-risk, low-probability events.
Advanced converters offer insurance against moderate growth in demand for electricity, compared to past experience, and limited supplies of uranium, so long as they are not expensive. Advanced converters would also be a useful adjunct to breeders in a breeder economy. Thus, conditions favorable to their development are also flexible.*
CONAES concludes that these considerations lead to the recommendation that both types of reactors should be developed. If only one type can be developed, breeders should receive priority, as covering more contingencies. If, for whatever reasons, development of the breeder is so long deferred as to preclude the option of commercialization in the early twenty-first century, the commitment should be made to expeditious development of the advanced converter.
The committee recommends the following course of action.
Development of the LMFBR should continue, but without immediate commitment to construction of prototype reactors. CONAES was divided on the issue of whether to recommend construction of the Clinch River breeder reactor as part of this development program.
A majority of the committee considered the Clinch River breeder