Why is nuclear energy non-renewable?

We think of all energy sources on Earth as "renewable," even though all energy is actually "non-renewable" because of the law of thermodynamics, which states that entropy is always increasing and that energy cannot be created or destroyed, only changed in form. Examples of these sources include wave, water, wind, biomass conversion, and direct photo-voltaic electrical production.

Even though the production of nuclear power is thought to be "cleaner" than that of "fossil fuels" (hydrocarbons), at least in terms of greenhouse gas generation, it still needs to use a finite mineral resource: uranium ores. These ores are not renewable, even though they may have very long lives, and they are only found in finite amounts on Earth.

Even though fusion power produces much more, it still uses more net physical resources and is generally cleaner for the environment than fission-produced power.

Nuclear energy is considered non-renewable because it relies on the extraction of uranium, a finite resource, which is used as fuel in nuclear reactors. Once uranium is used up, it cannot be easily replenished on a human timescale. Additionally, the process of mining and refining uranium has environmental impacts and is energy-intensive.