Secret US report : A secret document prepared by the US department of energy has ranked India seventh among countries poscsessing nuclear weapons. US experts believe India possesses 150 to 250 kilogrammes of weapons-grade plutonium-- enough to produce nearly 100 nuclear warheads. Russia tops the list with 140 tonnes of the material. The United States comes next with 85 tonnes. Britain follows with 7.6 tonnes, while France is estimated to possess between six and seven tonnes and China is believed to have roughly two tonnes of plutonium,