Fusion reactor for nuclear energy (Fusion)
Food irradiation (Gamma decay)
Emergency Exit Signs (Beta decay)
Smoke detectors (Alpha decay)
Radioactive iodine treatment (RAI) for imaging thyroid cancer (Gamma decay OR beta decay)
Providing power in space crafts (Alpha decay)
Using uranium-235 at nuclear power plants (Alpha decay; Fission)
Positron emission tomography (PET) scan to identify active parts of body (Beta decay)