ABSTRACT
Long-term sustainable energy sources are limited to solar, geothermal, fuel-efficient fission and fusion. Ultimate choices must have acceptable environmental and societal impacts. The laser fusion option, and particularly the fusion-fission hybrid breeder, carry with them strong technical implications for proliferation. Proof of the scientific feasibility of both magnetically confined fusion (MCF) and inertially confined fusion (ICF) may be close at hand, although technical and commercial feasibility are some distance away for both. Earlier entry into commercial feasibility may result if fusion sources are used to breed fissile Pu-239 or U-233, taking advantage of the resulting tenfold energy gain of fission over fusion. The result could be a practically inexhaustible energy source in, for example, reserves of fissionable (but largely non-fissile) uranium.
The status of MCF and ICF research is briefly reviewed in order to demonstrate the scale of effort in these areas and to identify the major participants. Attention is then focused specifically on the fusion-fission hybrid breeder. The hybrid breeder offers the possibility of breeding reactor fuel efficiently in only a few carefully guarded nuclear parks and potentially in proliferation-resistant forms. The MCF breeder has little implication for the development of nuclear weapon technology, and institutional arrangements for control of the fissile material produced can be similar to those in other areas. It is suggested that economic factors will be primary determinants in the choice between thorium and uranium raw materials, the latter appearing more likely at present. The ICF breeder, in contrast to the MCF breeder, carries dual implications for proliferation: the supply of fissile materials, and the spread of knowledge useful for development of a thermonuclear weapon capability. For this reason, some aspects of ICF research are protected by classification in the United States. ICF hybrids uniquely threaten to supply both ‘limiting ingredients’ essential for fusion weaponry—knowledge and fissile material. Although the danger is not immediate, any future unsafeguarded IQF hybrids should be regarded with suspicion.
