95Nb is the decay product of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35-day half-life alone.
Small amounts of other isotopes may be produced as direct fission products.
Its abundance relative to the stable 93Nb in the early Solar System, estimated at 1.7×10−5, has been measured to investigate the origin of p-nuclei.
[6][7] A higher initial abundance of 92Nb has been estimated for material in the outer protosolar disk (sampled from the meteorite NWA 6704), suggesting that this nuclide was predominantly formed via the gamma process (photodisintegration) in a nearby core-collapse supernova.
[8] Niobium-92, along with niobium-94, has been detected in refined samples of terrestrial niobium and may originate from bombardment by cosmic ray muons in Earth's crust.