| Prop: Unit: |
t½ Ma |
Yield % |
Q * KeV |
βγ * |
|---|---|---|---|---|
| 99Tc | 0.211 | 6.1385 | 294 | β |
| 126Sn | 0.230 | 0.1084 | 4050 | βγ |
| 79Se | 0.295 | 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 |
| Thermal | Fast | 14 MeV | |
|---|---|---|---|
| 232Th | not fissile | 6.46 ± 0.48 | 5.75 ± 0.23 |
| 233U | 6.950 ± 0.076 | 7.04 ± 0.38 | 5.66 ± 0.64 |
| 235U | 6.435 ± 0.089 | 6.06 ± 0.13 | 5.40 ± 0.58 |
| 238U | not fissile | 5.38 ± 0.26 | 4.59 ± 0.12 |
| 239Pu | 3.91 ± 0.13 | 3.92 ± 0.19 | secret |
| 241Pu | 2.95 ± 0.15 | 3.101 ± 0.078 | secret |
93Zr is a radioisotope of zirconium with a half life of 1.53 million years, decaying with a low-energy beta particle to Niobium-93m, which decays with a halflife of 14 years and a low-energy gamma ray to ordinary 93Nb. It is one of only 7 long-lived fission products. The low specific activity and low energy of its radiations limit the radioactive hazards of this isotope.
Nuclear fission produces it at a fission yield of 6.2956%, on a par with the other most abundant fission products. Nuclear reactors usually contain large amounts of zirconium as fuel rod cladding (see Zircaloy), and neutron irradiation of 92Zr also produces some 93Zr, though this is limited by 92Zr's low neutron capture cross section of 0.22 barns.
93Zr also has a low neutron capture cross section of 2.70 barns. Most fission zirconium consists of other isotopes; the other isotope with a significant neutron absorption cross section is 91Zr with a cross section of 1.24 barns. 93Zr is a less attractive candidate for disposal by nuclear transmutation than are Tc-99 and I-129. Mobility in soil is relatively low, so that geological disposal may be an adequate solution.
- ^ http://www-nds.iaea.org/sgnucdat/c1.htm Chain Fission Yields, IAEA
See also
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