Q3Power Generation Sources
Question
Q.3. What do you mean by fissile material?
Answer
A fissile material is an isotope capable of sustaining a nuclear fission chain reaction upon absorbing a slow (thermal) neutron, e.g., U-235, Pu-239 and U-233, which are used as nuclear reactor fuel.
Fissile materials are nuclides whose nucleus splits (undergoes fission) when it absorbs a low-energy (thermal) neutron, releasing a large amount of energy along with 2-3 more neutrons that can sustain a chain reaction. Examples are Uranium-235 (naturally occurring, 0.7% of natural uranium), Plutonium-239 and Uranium-233 (both produced artificially in reactors from fertile U-238 and Th-232 respectively). This is distinct from 'fertile' material, which itself does not fission with slow neutrons but can be converted into fissile material.