Neutron emission is typically associated with the fission of uranium or plutonium fuel in a nuclear reactor. However, there are other potential sources of neutrons that may be encountered. Understanding the fundamentals of the interaction of neutrons with matter and choosing the proper neutron shielding materials solution are important steps in working safely in areas where neutron radiation may be present.

Like gamma radiation, neutrons undergo scattering and absorption interactions with matter. These interactions form the basis for methods used to shield and measure neutron radiation. However, unlike gamma radiation, which interacts primarily with the electrons in matter, neutrons interact primarily with the nucleus. Consequently, the types of materials favored for neutron shielding are quite different than the dense, high atomic number absorbers which are most effective in the attenuation of gamma radiation. Additionally, whereas different isotopes of an element will have essentially identical gamma attenuation properties, different isotopes of an element often have significantly different neutron attenuation properties.