Nuclear reactors created not only large amounts of plutonium needed for the weapons programs, but a variety of other interesting and useful radioisotopes. They produced ⁶⁰Co, in which the non-conservation of parity was first discovered, and a number of transuranic isotopes that are used to study the limits of the periodic table. Reactors also produce isotopes for commercial and medical purposes:

1. ²⁴¹Am–used in smoke detectors,
2. ⁶⁰Co–used in industry to inspect weld quality, also used in cancer therapy,
3. ^99mTc–used for medical diagnosis, and
4. ¹³⁷Cs–also used for medical therapy.

Reactor neutrons have been used for material studies that involve their scattering from the crystal planes.