fissile

https://doi.org/10.1351/goldbook.F02394
  1. (of a @N04257@) Capable of undergoing fission by interaction with (slow) neutrons.
  2. (of a material) Containing one or more fissile nuclides.
Source:
PAC, 1982, 54, 1533. 'Glossary of terms used in nuclear analytical chemistry (Provisional)' on page 1542 (https://doi.org/10.1351/pac198254081533)