How does the fuel become more radioactive?

Typically, LWRs use uranium enriched to 3–5\% U-235, the only fissile isotope that is found in significant quantity in nature. During the nuclear reaction inside a reactor, the fissile isotopes in nuclear fuel are consumed, producing more and more fission products, most of which are considered radioactive waste.

How does nuclear fuel become radioactive?

During the fission process, two things happen to the uranium in the fuel. First, uranium atoms split, creating energy that is used to produce electricity. The fission creates radioactive isotopes of lighter elements such as cesium-137 and strontium-90.

What would happen in a nuclear reactor with no control rods?

If all control rods are fully removed, reactivity is significantly above 1, and the reactor quickly runs hotter and hotter, until some other factor slows the reaction rate. Control rods are partially removed from the core to allow the nuclear chain reaction to start up and increase to the desired power level.

What is fuel rod in nuclear reactor?

A long, slender, zirconium metal tube containing pellets of fissionable material, which provide fuel for nuclear reactors. Fuel rods are assembled into bundles called fuel assemblies, which are loaded individually into the reactor core.

What do fuel rods do in a nuclear reactor?

The purpose of the fuel rod is to keep the fuel in a well-defined geometry and to provide the first barrier separating the fission products from the environment. Preserving its integrity is therefore the primary goal of fuel design and rules for reactor operation.

Why are the multiple fuel rods in a nuclear reactor?

The fuel rods: source of enriched Uranium fuel that undergoes fission reactions. The moderator: the fuel rods are encased in the moderator (graphite is sometimes used) and help the fission reaction to proceed efficiently. The control rods: normally made of Boron, these help control the fission reaction.

Which substance is commonly used in the fuel rods of a nuclear reactor?

Reactors use uranium for nuclear fuel. The uranium is processed into small ceramic pellets and stacked together into sealed metal tubes called fuel rods. Typically more than 200 of these rods are bundled together to form a fuel assembly.