Patent Number: 052992411
Section: claims

1. In a transuranium element transmuting fast reactor core in which a fast reactor contains a plurality of fuel assemblies, said fuel assemblies comprising fuel pellets containing a minor actinide elements and a fissionable fuel, the amount of said minor actinide elements being controlled so as to prevent melting of said fuel pellets in said fuel assemblies, the improvement wherein the amount of .sup.242 Cm, .sup.244 Cm and .sup.241 Am in a said fuel assembly satisfy the equation EQU 1.2.times.10.sup.2 .times.M.sub.242 +2.8.times.M.sub.244 +1.1.times.10.sup.-1 .times.M.sub.241 &lt;Q.sub.1 2. The reactor core of claim 1, wherein said fuel assembly contains an amount of minor actinide elements sufficient to maintain the excess reactivity of the reactor at substantially zero during operation of the reactor, wherein said excess reactivity is the amount of fissionable elements produced by neutron capture by said minor actinide elements which exceeds fissionable elements transmuted by fission of said fissionable fuel. 3. The reactor core of claim 1, wherein said fuel assemblies contain fissionable plutonium fuel and said core contains a core area having a central portion wherein the plutonium concentration in said core area is uniform and wherein the concentration of minor actinides decreases radially from said central portion of said core area. 4. The reactor core of claim 1, wherein said fuel assemblies contain fissionable plutonium fuel and said core contains a first core area having a first plutonium concentration and a second core area having a second plutonium concentration, wherein the plutonium concentration in said first core area is higher than the plutonium concentration in said second core area and wherein the concentration of minor actinide in said first core area is higher than the concentration of minor actinide in said second core area.