Sample Problem 11. TRX-1 Infinite Lattice Cell

  TEST 11 -- TRX-1 INF. LATTICE CELL
  0  5  0  1  2  1  0  3  69  3
  2  2  10  40  1  1  3  5  4  3
  CELL
  FUEL  300  .75892  3  1.15  1.15/
  CLAD  300  .28085  -3/
  MOD  300  1.78489  -3/
  1  1  U235  6.253E-4  FREE/
  1  1  U238  4.7205E-2  FREE/
  1  2  AL27  5.1728E-2  FREE/
  1  3  H1  6.676E-2  H20/
  1  3  016  3.338E-2  FREE/
  CHI  F238  F235  C238
  2  NFTOT  1  U238
  3  NFTOT  1  U235
  4  NG  1  U238
  45  24/
  STOP

The entire self-shielding calculation is repeated, but this time everything is homogenized into IMIX=1 using the given volumes and the computed region flux moments from the RZMFLX file. Note that the results are collapsed into two groups. The resulting breakpoint will be at 0.625 eV so that the response edits can be used to calculate the epithermal-to-thermal ratios usually quoted for thermal critical assemblies. These two-group cross sections could also be used to calculate the net leakage from the system using a two-dimensional RZ transport code, thereby determining whether the basic cross-section set gives a multiplication close to critical.