Nuclear Materials in SCONE

Material Properties

Materials in SCONE define how neutrons interact with different regions of your geometry. Each material requires a temperature specification that affects nuclear cross-sections, and a composition listing nuclides at the density basis used by your library workflow. The examples below follow your working input style with ACE-based `nuclearData`.

nuclearData {
  handles {
    ce { type aceNeutronDatabase; aceLibrary /path/to/JEF311.aceXS; }
  }
  materials {
    Water {
      temp 600;
      composition {
        1002.06 7.7035E-06;
        8016.06 2.4673E-02;
        8017.06 9.3734E-06;
      }
    }
    Zircaloy {
      temp 600;
      composition {
        40090.06 2.1828E-02;
        40091.06 4.7601E-03;
        40092.06 7.2759E-03;
        40094.06 7.3734E-03;
        40096.06 1.1879E-03;
      }
    }
  }
}

Advanced Features

For core models, the practical complexity is isotope completeness and consistency across structural and fuel materials, not optional keyword tuning.

nuclearData {
  materials {
    UO2-31 {
      temp 600;
      composition {
        8016.06   4.5853E-02;
        8017.06   1.7420E-05;
        92234.06  5.7987E-06;
        92235.06  7.2175E-04;
        92238.06  2.2253E-02;
      }
    }
    Inconel {
      temp 600;
      composition {
        24052.06 1.5088E-02;
        26056.06 2.3229E-02;
        28058.06 2.9320E-02;
      }
    }
  }
}

Material Tips

• Use ZAID.NN format (e.g. 92235.06) for nuclide identifiers
• Set temp to match your cross-section library temperatures
• Composition values are atom densities; ensure they sum correctly

Next Steps

With materials defined, add neutron sources. The Sources section covers criticality vs. fixed-source mode and how to specify source distributions.