Frank von Hippel and colleagues review some disposal options for radioactive plutonium waste (Nature 485, 167–168; 2012). Another option is the profitable consumption of plutonium from thermal nuclear plants in a fast-spectrum breeder reactor with fuel recycling.
A prototype Integral Fast Reactor was operated at the Argonne West National Laboratory in Idaho for 30 years until 1994. 'Burning' spent nuclear fuel produces a fraction of the waste of current reactors, and it has low radiotoxicity (W.H. Hannum (ed.) Prog. Nucl. Energy 31, 1–217; 1997).
The reactor's metal fuel (mainly uranium, plutonium and zirconium) and liquid-sodium coolant provide passive safety. An unpressurized pool vessel disperses decay heat by natural convection, even when cooling pumps are inoperable and the heat sink is lost.
The fuel-recycling system generates vast amounts of clean electricity, extending uranium supplies 150-fold — unlike today's once-through-and-throw-away cycle. Its proliferation risk is low because the products are unsuitable for use in fissile weapons.
The company GE Hitachi has designed an integral fast reactor, the 311-megawatt electric Power Reactor Innovative Small Module (PRISM), that is intended for commercial use. A prototype plant is already being considered in the United States, and the company has recommended these plants to the UK government for plutonium disposal (see go.nature.com/dwiqvg).