1. (noun) a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons

• atomic number 94
• plutonium
• pu

1. (noun) a highly fissionable isotope of plutonium that is used in atomic weapons and as a reactor fuel; produced by irradiating uranium 238 with slow electrons

• weapon-grade plutonium
• weapons plutonium