technetium-99

Technetium-99 (⁹⁹Tc) is an isotope of technetium which decays with a half-life of 211,000 years to stable ruthenium-99, emitting beta particles[1] but no gamma rays. It is the most significant long-lived fission product of uranium fission, producing the largest fraction of the total long-lived radiation emissions of nuclear waste. Technetium-99 has a fission product yield of 6.0507 or thermal neutron fission of uranium-235.