Coprocessing is conceived as a method in which the plutonium is never available in a separate stream. In addition, it is possible to keep the transuranium actinides with the plutonium and uranium streams rather than allowing them to leave with the fission products and terminate in the high level waste. The recovered actinide product can be reconstructed as a fuel and recycled in light water reactors. But even after nine cycles the fuel composition does not reach equilibrium. Since the plutonium is never separated from other actinides, the potential of proliferation can be reduced.