1.   But recycled plutonium fell out of favor over the years, except in Japan, as uranium fuel became cheaper.

2.   The comments also come as Japanese nuclear officials prepared to send back a possibly faulty shipment of fuel made of recycled plutonium and uranium to a maker in Britain.

3.   The Japanese government continues to urge the use of recycled plutonium, which critics say is a dangerously volatile form of nuclear fuel.

4.   Under the plan, recycled plutonium will be fed into light-water reactors in a mixture with uranium so it burns in a similar manner as enriched uranium.