6.1.6.1. XSDRNPM Data File Formats

As part of the development of the sensitivity capabilities in SCALE, the XSDRNPM module was modified to allow the writing of a new interface file containing information needed for sensitivity calculations. This same data file is used by TSUNAMI-1D. This information is written on unit NTD in the XSDRNPM input, when NTD is positive. When TSUNAMI-1D creates the inputs for the forward and adjoint XSDRNPM criticality calculations, NTD is set to 31 for the forward case and 32 for the adjoint case. The files written are ft31f001 and ft32f001, respectively.

6.1.6.2. XSDRNPM forward output file

For a forward case, XSDRNPM writes the following unformatted records on unit NTD:

RECORD 1:  IZM,IM,MXX,MS,ISCT,MM,JT,IGM
IZM - Number of zones
IM - Number of spatial intervals
MXX - Number of compositions (mixtures)
MS - Length of the XSDRNPM mixing table
ISCT - Order of the Legendre scattering expansion
MM - Number of angles in the angular quadrature
JT - Number of flux moments
IGM - Number of energy groups
RECORD 2:  IGE,IBL,IBR,ISN,IFTG,MMT,NT1,T
IGE - Geometry: 1/2/3 = plane/cylinder/sphere
IBL - Left-boundary condition: 0/1/2/3 = vacuum/reflected/periodic/white
IBR - Right-boundary condition
ISN - Sn quadrature order
IFTG - First thermal group
MMT - Number of neutron groups
NT1 - Unit number of working cross-section library
T - Problem title containing 80 characters
RECORD 3:  V,R
V(IM) - Volumes of the spatial mesh cells (single-precision)
R(IM+1) - Boundaries of the spatial mesh cells (single-precision)
RECORD 4:  W,PNC
W(MM) - Weights in the angular quadrature (single-precision)
PNC(MM,JT) - Scattering constants used to obtain flux moments from angular fluxes (single-precision)
RECORD 5:  MA,MZ
MA(IM) - Zone number by interval
MZ(IZM) - Mixture number by zone
RECORD 6:  MB,MC,XMD
MB(MS) - Mixture number in the cross-section mixing table
MC(MS) - Component (nuclide) in the cross-section mixing table
XMD(MS) - Atom density in the cross-section mixing table (single-precision)
RECORD 7:  CHI,FISNU
CHI(IGM,MXX) - \(\chi\) for each mixture (single-precision)
FISNU(IGM,MXX) - \(\bar{v}\) times the fission cross section for each mixture (single-precision)
RECORD 8:  EIGEN
EIGEN keff (single-precision)
NEXT IGM RECORDS:  XNDC
XNDC(IM,MM) - Mesh cell centered angular flux for one group (double-precision)
LAST RECORD:  TLEAKAGE
TLEAKAGE(IGM) - Total leakage from the system (single-precision)

6.1.6.3. XSDRNPM adjoint output file

For an adjoint case, XSDRNPM writes the following unformatted records on unit NTD, containing the following information:

RECORD 1:  EIGEN
EIGEN - keff value (single-precision)
NEXT IGM RECORDS:  XNDC
XNDC(IM,MM) - Mesh cell centered angular flux for one group (double-precision)

The adjoint angular fluxes are reversed in direction such that each angular flux is the importance for that direction in the forward case. This reversal is done by using the reflected angle. Also, the records are written in forward order such that the first record corresponds to the highest-energy group.