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How is plutonium-239 produced from uranium-238 in a nuclear reactor?

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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. — transuranium element Modern version of the periodic table of the elements (printable).

In a nuclear reactor, plutonium-239 is produced from uranium-238 through a process of neutron capture followed by successive beta decays.123

The transformation occurs in the following sequence:

Neutron Capture: A uranium-238 nucleus absorbs a neutron to become the isotope uranium-239.13
First Beta Decay: Uranium-239 is unstable and undergoes negative beta-particle decay with a half-life of approximately 23.5 minutes. During this process, a neutron in the nucleus is transformed into a proton, emitting a beta particle and converting the atom into neptunium-239.143
Second Beta Decay: Neptunium-239 is also unstable and undergoes further beta decay, with a half-life of about 2.356 days, to yield plutonium-239.13

This process allows fertile uranium-238 to be converted into fissile plutonium-239, which can then be used as fuel in nuclear power reactors or for other applications.123