Sodium
Na
Moderators & CoolantsDensity: 0.971 g/cm³
Atom density: 0.025435 atoms/b·cm
Sodium coolant for sodium-cooled fast reactors — EBR-II, BN-600/800, Natrium.
Where these numbers come from
PNNL-15870 Rev. 2, "Sodium" (id sodium): density and full isotopic composition are taken from the compendium unchanged.
Open the compendium entry for the isotope-by-isotope table and the compendium's own notes.
Material compositions from PNNL-15870 Rev. 2 (April 2021), R.S. Detwiler, R.J. McConn Jr., T.F. Grimes, S.A. Upton, and E.J. Engel, Compendium of Material Composition Data for Radiation Transport Modeling, Pacific Northwest National Laboratory. Full report (DOI 10.2172/1782721)
Composition
| Nuclide (ZAID) | Weight fraction | Atom fraction | Atom density (atoms/b·cm) |
|---|---|---|---|
| Na-23 (11023) | 1.0000e+0 | 1.0000e+0 | 2.5435e-2 |
This is the material as formulated. The cards below carry weight fractions, written negative, which is what MCNP and Serpent read as a mass basis.
Generated material cards
c Sodium
c PNNL-15870 Rev. 2, "Sodium" - reactormc.net/nrdp/material/sodium; rho = 0.971
c g/cm3 (use -0.971 on the cell card)
m23 11023.80c -1.000000 $ Na23MCNP and Serpent cards use .80c (ENDF/B-VII.1 at 293.6 K) — renumber m1 and change the suffix to match your deck. SCONE compositions are atom densities in atoms/barn-cm with the .03 suffix matching temp 300. See the library reference before changing a suffix: the mapping is not portable between vendors.
Notes
The compendium density is for solid sodium at room temperature. Liquid sodium at SFR operating temperature (~500 °C) is about 0.85 g/cm³, and the coolant density coefficient is a central safety parameter in an SFR, so do not leave this at the room-temperature value. Na-23 is the only stable isotope.