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, 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% for thermal neutron fission of uranium-235.
Technetium-99m is a short-lived (half-life about 6 hours) metastable nuclear isomer used in nuclear medicine, produced from molybdenum-99. It decays by isomeric transition to technetium-99, a desirable characteristic, since the very long half-life and type of decay of technetium-99 imposes little further radiation burden on the body.
Prop: Unit: |
t½ Ma |
Yield % |
Q * KeV |
βγ * |
---|---|---|---|---|
99Tc | 0.211 | 6.1385 | 294 | β |
126Sn | 0.230 | 0.1084 | 4050 | βγ |
79Se | 0.327 | 0.0447 | 151 | β |
93Zr | 1.53 | 5.4575 | 91 | βγ |
135Cs | 2.3 | 6.9110 | 269 | β |
107Pd | 6.5 | 1.2499 | 33 | β |
129I | 15.7 | 0.8410 | 194 | βγ |
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