Britannica Sources used in this answer

Why could thorium help extend supplies of nuclear fuel?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — actinoid element Modern version of the periodic table of the elements (printable).

Thorium can help extend nuclear fuel supplies because it is a fertile material, meaning it can be transformed into fissile fuel within a nuclear reactor.12

While natural thorium consists primarily of the isotope thorium-232, which is not itself fissile, it can undergo neutron capture when bombarded by neutrons in a reactor. This process converts thorium-232 into the fissile isotope uranium-233.12

Because thorium is approximately three times more abundant in the Earth's crust than uranium, its ability to be converted into usable fuel represents a potentially vast source of nuclear energy. By utilizing fertile materials like thorium, reactors can partially replace the fissile material consumed during operation, allowing them to run for longer periods. However, realizing this potential requires overcoming significant technical and economic barriers related to the extraction and conversion of the material.321