# 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 zonesIM - Number of spatial intervalsMXX - Number of compositions (mixtures)MS - Length of the XSDRNPM mixing tableISCT - Order of the Legendre scattering expansionMM - Number of angles in the angular quadratureJT - Number of flux momentsIGM - Number of energy groups

- RECORD 2: IGE,IBL,IBR,ISN,IFTG,MMT,NT1,T
- IGE - Geometry: 1/2/3 = plane/cylinder/sphereIBL - Left-boundary condition: 0/1/2/3 = vacuum/reflected/periodic/whiteIBR - Right-boundary conditionISN - S
_{n}quadrature orderIFTG - First thermal groupMMT - Number of neutron groupsNT1 - Unit number of working cross-section libraryT - 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 intervalMZ(IZM) - Mixture number by zone

- RECORD 6: MB,MC,XMD
- MB(MS) - Mixture number in the cross-section mixing tableMC(MS) - Component (nuclide) in the cross-section mixing tableXMD(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
*k*_{eff}(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 -
*k*_{eff}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.