The Chinese have expressed ambiguity about whether North Korea has a secret program to extract nuclear fuel from uranium in addition to its better known effort to make bombs from plutonium.

On a recent cruise to Antarctica, our vessel, the Professor Molchanov, was delayed two days in port while the ship's leasing agent struggled to extract prepaid fuel from the local authorities.

Aside from inspections, spy satellites and airborne "sniffers" can usually pick out the huge complexes needed to extract spent fuel from nuclear reactors and turn it into bomb fuel.

India has the capability to use thorium cycle based processes to extract nuclear fuel.

After North Korea declared last week that it had extracted weapons-grade fuel from a nuclear reactor, South Korea and China dismissed punitive options like economic sanctions.

That would allow technicians to extract spent fuel and divert the plutonium in the fuel to the manufacture of atomic bombs.

The big gray sheds were for reprocessing nuclear waste, extracting usable fuel from spent material.

Chemical plant: Build these on fuel deposits to extract fuel.

The new bacteria, according to its inventors, can convert virtually all kinds of sugars, making it possible to extract fuel from almost anything produced by plants: grass clippings, wheat stalks, cardboard, grocery bags and newsprint.

In Ottenstein an oil mill was built to extract fuel from rapeseed.