<?xml version='1.0' encoding='utf-8'?>
<model>
  <materials>
    <material depletable="true" id="1" name="UO2">
      <density units="g/cm3" value="10.29769"/>
      <nuclide ao="4.4843e-06" name="U234"/>
      <nuclide ao="0.00055815" name="U235"/>
      <nuclide ao="0.022408" name="U238"/>
      <nuclide ao="0.045829" name="O16"/>
    </material>
    <material id="2" name="light water">
      <density units="g/cm3" value="1.0"/>
      <nuclide ao="2.0" name="H1"/>
      <nuclide ao="1.0" name="O16"/>
      <sab name="c_H_in_H2O"/>
    </material>
  </materials>
  <geometry>
    <cell id="1" material="1" region="-1" universe="1"/>
    <cell id="2" material="2" region="1" universe="1"/>
    <cell fill="2" id="3" region="2 -3 4 -5" universe="3"/>
    <lattice id="2">
      <pitch>1.2 1.2</pitch>
      <outer>1</outer>
      <dimension>2 2</dimension>
      <lower_left>-1.2 -1.2</lower_left>
      <universes>
1 1 
1 1 </universes>
    </lattice>
    <surface coeffs="0.0 0.0 0.4" id="1" type="z-cylinder"/>
    <surface boundary="reflective" coeffs="-1.2" id="2" name="minimum x" type="x-plane"/>
    <surface boundary="reflective" coeffs="1.2" id="3" name="maximum x" type="x-plane"/>
    <surface boundary="reflective" coeffs="-1.2" id="4" name="minimum y" type="y-plane"/>
    <surface boundary="reflective" coeffs="1.2" id="5" name="maximum y" type="y-plane"/>
  </geometry>
  <settings>
    <run_mode>eigenvalue</run_mode>
    <particles>1000</particles>
    <batches>10</batches>
    <inactive>5</inactive>
  </settings>
  <tallies>
    <filter id="1" type="energy">
      <bins>0.0 0.253 1000.0 1000000.0 20000000.0</bins>
    </filter>
    <filter id="2" type="distribcell">
      <bins>1</bins>
    </filter>
    <tally id="1" name="distribcell tally">
      <filters>1 2</filters>
      <nuclides>U234 U235 U238</nuclides>
      <scores>nu-fission total</scores>
    </tally>
  </tallies>
</model>
