<?xml version="1.0"?>
<materials>

  <material id="1">
    <density value="4.5" units="g/cc" />
    <nuclide name="U235" ao="1.0" />
    <nuclide name="H1" ao="0.5" />
    <nuclide name="C0" ao="0.5" />
  </material>

</materials>
