Turning the world’s biggest civilian plutonium stockpile into electricity
07 December 2011
GE Hitachi Nuclear Energy has proposed to the UK government to build an advanced nuclear reactor that would consume the country’s stockpile of radioactive plutonium. The technology called PRISM, or Power Reactor Innovative Small Module, would use the plutonium to generate low-carbon electricity. At 87 tons, the UK has the world’s largest civilian stockpile of plutonium, and it is growing.

Conventional reactors use water cooling, but water-cooled reactors leave some 95 percent of the fuel’s potential energy untapped. PRISM is a so-called “fast reactor.” It uses liquid sodium, rather than water, to cool the reactor allowing the neutrons to maintain higher energies and improving the efficiency of the fission reaction.
PRISM incorporates 'passive safety' features and can shut down automatically in the unlikely event that such an action is needed. PRISM does not require automatic systems, valves or operators to remove reactor heat after a shutdown with a complete loss electrical power.
Another benefit is PRISM’s relatively small size and simplified design. The reactor can be built in modules and transported to the power plant site, lowering the costs and adding another level of component control.
GE Hitachi Nuclear Energy says that the PRISM reactor would use practically all the plutonium stored at Sellafield to create low-carbon electricity, turning it into an asset.