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y IC12, if the eigenvalue problem or the external neutron source problem in the
whole energy range is solved. (e.g. shell source or distributed source in ANISN,
inhomogeneous source or boundary source in TWOTRAN, point source in
CITATION)
Enter IC2=1 if the PEACO routine is used by IC5=2 or =-2 for the resonance
absorption process.
[cf.] Sect.1.7, Sect.1.10
IC3
Selection of the process to get the Dancoff correction factor
The Dancoff correction factor is used in the two steps; first for the
heterogeneous effect on the admixture cross-sections in the interpolation of
resonance shielding factors upon NR approximation, second for the IR
approximation of absorption calculations of resolved resonance levels.
= 0 Use the input value specified in the material specification (cf. Sect.2.9)
= 1 Calculate by CPM
= 2 Calculate by the Tone’s method 12)
Note:
The Tone’s method is recommended for a plate type cell with neighboring
different fuels, but it is not recommended for a pin type cell.
When the double heterogeneity is solved by the PEACO routine by specifying a
negative value of MAR (Block-6 in Sect. 2.4), the Dancoff correction factor of the
microscopic heterogeneity in the material specification is used in spite of any IC3
value while that of the macroscopic heterogeneity is controlled by the IC3 value.
[cf.] Sect.1.6, Sect.2.4
IC4
Indicator for the energy range solved
= 0 Thermal range is excluded (for fast neutron reactors)
= 1 Thermal range is included (for thermal neutron reactors)
IC5
Selection of the process for resonance absorption in the resonance energy range
= 0 Interpolation of Bondarenko type table by NR approximation(NRA).
= 1 Interpolation of Bondarenko type table by IR approximation (IRA).
The IRA routine works for only one resonant R-Region (which contains
at least one nuclide(s) with IRES=2 in the material specification) in a
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