Hafnium
Hf
AbsorbersDensity: 13.31 g/cm³
Hafnium metal control rod absorber. All stable Hf isotopes have significant absorption cross sections, providing long control rod lifetime without depletion concerns.
Composition
| Nuclide / Element | Fraction |
|---|---|
| Hf-174 | 0.001600 |
| Hf-176 | 0.052600 |
| Hf-177 | 0.186000 |
| Hf-178 | 0.272800 |
| Hf-179 | 0.136200 |
| Hf-180 | 0.350800 |
Code output
MCNP
c Hafnium Metal (natural isotopics)
c Density: 13.31 g/cm3 (use -13.31 on cell card)
m36 72174.80c 0.001600 $ Hf-174
72176.80c 0.052600 $ Hf-176
72177.80c 0.186000 $ Hf-177
72178.80c 0.272800 $ Hf-178
72179.80c 0.136200 $ Hf-179
72180.80c 0.350800 $ Hf-180Notes
All six stable Hf isotopes have significant absorption cross sections. Successive neutron captures transmute Hf through its isotope chain, maintaining absorber effectiveness over long irradiation periods. Used in naval reactor control rods.