Ordinary nuclear power plants use uranium, Z=92, as their fuel.
Nuclear fission has done and is doing a great service to the mankind. However, the uranium still has several disadvantages. The waste products remain radioactive for thousands of years. And the world's reserves of uranium are only enough to cover less than a century of the mankind's energy consumption.
Thorium, Z=90, avoids both of these problems and a few others. China has started a new program to develop a molten salt reactor based on thorium:
The technology has been tried already in the 1950s and it was running in Oak Ridge between 1965 and 1969. The power plants may be smaller and they are safer. Kazuo Furukawa's private company - which has already built the Fuju reactor - hopes to produce a reactor in 5 years. The electricity could be profitable at current energy market prices. He even talks about a personal reactor in your garage.
Thanks to Peter F.