Material Densities and. Atomic Weights

2) the material densities and atomic weights, 3) the number of neutrons released per fission, k) the parameters describing the moderating ability of the materials (principally the moderators), 3) the angular distributions of neutrons scattered from the atoms of the various materials, etc These properties are discussed in the following sections. 

The densities, atomic or molecular weights, and nuclear densities of the principal reactor materials are listed in Table 2 3 1.1 at room temperature (20 C) and for operating reactor conditions  

Material Atomic or Mol. Wt. Density gm/cm3 20 c Oueratina Nuclear Density Nuclel/cm3 (20 ( 

The appropriate cross sections for the nuclear reactions tahlng place In a reactor are dependent on the particular neutron accounting procedure employed In the reactor physics calculations. The usual Banford procedure Is to calculate the effective multiplication factor of the reactor via the veU-knoiin Fenal four factor foxtnula. (Section 2.2) 

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