In the years following the Second World War, the Manhattan Project in the US demonstrated the raw energy that could be created by nuclear fission or ‘splitting the atom’. The two bombs dropped on Japan to end the conflict also heralded the era of nuclear power.

Attention turned to non-military uses of atomic power. By 1951, a small, experimental reactor in Idaho, ‘EBR-I’, had produced the first nuclear-generated electricity, feeding into an existing grid. Three years later, the Soviet Union became the first country to manufacture nuclear power at commercial scale.

Power to the people

The Soviet Union’s nuclear reactor programme began in Obninsk at the Institute of Physics and Power Engineering, 60 miles southwest of Moscow. The 5 MW (megawatts) reactor built there was a channel-type uranium-graphite design that laid the foundation for reactors such as Sellafield.

All reactors run on similar principles, using radioactive rods as fuel. Heat is generated by nuclear fission, while water is pumped through the reactor to cool it. The hot water generates steam which drives turbines and, in turn, electrical generators. The goal of nuclear power was cheap, emissions-free electricity and it was regarded as future by the many countries that adopted it. France, for example, now receives 75% of its electricity from nuclear reactors and continues to invest in it.

Yes, please! Or, no thanks?

Obninsk ran for almost five decades until it closed in April 2002. Today there are 442 nuclear power plants operating in 31 countries. Sixty-six more reactors are under construction in another 16 countries. Many of these use the new breed of pressurised water reactors.

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