# thorium

/ˈθɑɹiəm/ (US) · /θˈɔːɹiəm/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/thorium
Updated: 2026-05-26

## Definition

a heavy, radioactive metal that is found in nature. It is similar to uranium and can be used to create energy in special types of nuclear reactors.

For teachers: a radioactive metallic chemical element with the symbol Th and atomic number 90. It is a fertile material that can be converted into fissile uranium-233 within a nuclear reactor.

## Examples

- Scientists are studying thorium as a safer alternative to uranium.
- Unlike traditional uranium reactors, molten salt reactors can utilize thorium to produce energy with less long-lived radioactive waste.
- The abundance of thorium in the Earth's crust makes it a potentially significant resource for future nuclear energy production, though its commercial deployment remains limited by current technological constraints.

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