Which material is a naturally occurring fuel feedstock used in some nuclear reactors?

Which material is a naturally occurring fuel feedstock used in some nuclear reactors?

• A. Smoke Detectors
• B. Natural Uranium
• C. High Level Radiation
• D. Plutonium

Answer: (B)

Natural uranium is used as a fuel feedstock in some reactors because it exists in nature and contains a small amount of fissile uranium-235. About 0.7% of natural uranium is U-235, with the rest mostly U-238. In reactors with a very efficient neutron economy, such as heavy-water moderated designs, that small fraction is enough to sustain a chain reaction, so enrichment isn’t required. Smoke detectors don’t provide fuel; they use americium-241. High level radiation describes a hazard, not a fuel material. Plutonium is produced in reactors and isn’t obtained as a natural feedstock in the same way as natural uranium.

Natural uranium is used as a fuel feedstock in some reactors because it exists in nature and contains a small amount of fissile uranium-235. About 0.7% of natural uranium is U-235, with the rest mostly U-238. In reactors with a very efficient neutron economy, such as heavy-water moderated designs, that small fraction is enough to sustain a chain reaction, so enrichment isn’t required. Smoke detectors don’t provide fuel; they use americium-241. High level radiation describes a hazard, not a fuel material. Plutonium is produced in reactors and isn’t obtained as a natural feedstock in the same way as natural uranium.