In the mid-1950's nuclear fission had still to be turned into a commercial power source.

Technetium-99 is produced by the nuclear fission of both uranium-235 and plutonium-239.

Talking as if the secret of nuclear fission was something new.

She was the first to mention the idea of nuclear fission in 1934.

It was a bit like watching very slow nuclear fission.

The knowledge of nuclear fission was the line he decided to draw.

What if he was spoken of as a coming man in nuclear fission?

It was an important step in the discovery of nuclear fission.

This situation, however, changed in the late 1930s, with the discovery of nuclear fission.

He wondered if the Japanese were working on nuclear fission.