Neptunium-237 is a transuranic radioactive material with a long physical half-life (2.14 million years). Neptunium-237 is produced by irradiating plutonium with neutrons in a nuclear reactor. The primary use for Np-237 is in-core nuclear reactor dosimetry, and as target material for reactor productions of plutonium-238.
We have preserved a small amount (less than 150 g) of high-purity neptunium-237 oxide powder and metal wire, previously identified as excess, for scientific research. Neptunium-237 is available from our Laboratory by requesting this material through the National Isotope Development Center at Oak Ridge National Laboratory.