Co
Cobalt
Z = 27 · Transition Metal · 58.9 u
Nuclear Engineering Significance
Impurity in structural steels that produces Co-60 (t₁/₂ = 5.27 y, strong gamma emitter) by neutron activation — a dominant source of occupational dose during reactor maintenance. Thermal absorption (σ_a = 37.2 b) is significant. Cobalt content is strictly limited in reactor-grade steels.
Basic properties
- Atomic number (Z)
- 27
- Standard atomic mass
- 58.9 u
- Category
- Transition Metal
Isotopes & cross-section data
| Isotope | Mass (A) | Half-life | ZAID | Libraries |
|---|---|---|---|---|
| Co-59 | 59 | Stable | .80c.71c.70c |