11.6. MALOCS2: Module To Collapse AMPX Master Cross Section libraries

L.M. Petrie

11.6.1. Introduction

MALOCS2 (Miniature AMPX Library Of Cross Sections) is a module to collapse AMPX master cross-section libraries. The SCALE MALOCS2 module is an extension of the AMPX module MALOCS. MALOCS2 provides capability to read the collapsing spectrum from the output flux file produced by XSDRNPM, and also has extended options for collapsing Legendre moments of the 2D elastic scattering matrix. The module can be used to collapse neutron, gamma-ray, or coupled neutron-gamma master libraries.

11.6.2. MALOCS Input Data

broadfilename

filename of the collapsed library [no default]

crosssectionprint

cross section printing option [none]

none - don’t print any cross sections

onedxsecs - print the 1D cross sections

twodxsecs N - print the 2D cross sections through Legendre order N

epsilon

epsilon for when to print invalid moment messages[0.05]

finefilename

filename of the input library [no default]

fluxfilename

filename of an xsdrn flux file to be used in the collapse [no default]

numgammagroups

the number of fine gamma groups [no default]

gammacollapse

the broad group by fine group collapse structure for the gammas

must come after “numgammagroups”

latticezones

identifies the zones to be used as fuel, gap, clad, and moderator [1,2,3,4]

max2dweightorder

maximum Legendre order to be collapsed [max Legendre order of the nuclide]

numneutrongroups

the number of fine neutron groups [no default]

neutroncollapse

the broad group by fine group collapse structure for the neutrons

must come after “numneutrongroups”

printepsilon

not used [2.0D-6]

problemfilename

filename of the xsdrn data file that corresponds to the flux file [no default]

sigmatotalpl

flag to turn on doing a within group correction using the Pl weighted sigma total

‘y’ or ‘yes’ is true, anything else is false [true]

updatechi

flag to turn on updating the total chi

‘y’ or ‘yes’ is true, anything else is false [true]

validate2ds

flag to validate the Legendre moments of the collapsed 2D cross sections

‘y’ or ‘yes’ is true, anything else is false [true]

weighttype

type of weighting to be done

innercell - cell weight over a subset of the zones

innercell is followed by the largest zone number in the innercell

cell - cell weight over the whole cell

zone - weight each zone independently

region - cell weight each nuclide over only the zones it is in

default is region

wgtsource

source of the weighting flux

nuclideflux - use the flux from the nuclide on the fine group library

inputflux - read a flux from input

[default is to use an xsdrn flux]

end

terminates input stream

11.6.3. MALOCS Example Problem

The following problem shortens the 56 group library to just the nuclides that will be used to run a fixed source, 1-D discrete ordinates calculation of a void sphere with a neutron source in it, surrounded by a sphere of water, and then surrounded by an iron sphere. The flux from the discrete ordinates problem is then used to collapse the short library to 14 groups using a zone collapse method. Finally, the collapsed library is listed showing the nuclides on it, and copied back to the input directory.

=shell
  ln -s ${DATA}/scale.rev04.xn56v7.1 ft51f001
end
=ajax
  0$$ 52 e
  1$$ 1  1t
  2$$ 51 8  2t
  3$$ 1001 1002 8016 8017 26054 26056 26057 26058 3t
end
=csas1   parm=bonami
generate a flx file to be used to collapse a library
v7-56n
read composition
  iron  1 1.0 293.0  end iron
  water 2 1.0 293.0  end water
end composition
read celldata
  multiregion spherical end
  0 1.0  2 10.0  1 15.0  end zone
  moredata
    ievt=0 iqm=1 ntd=61 fwr=62 source(1)=15
    0.2 0.2 0.2 0.5 0.5 0.5 0.5 0.5 0.5 0.2 0.2 0.2 0.05 0.05 0.05
  end moredata
end celldata
end
=malocs2
' the input fine group cross section library to be collapsed
  finefilename=ft52f001
' the output collapsed cross section library
  broadfilename=ft53f001
' the file with the fluxes from xsdrn to be used to collapse the XSs
  fluxfilename=ft62f001
' the file containing the description of the xsdrn problem
  problemfilename=ft61f001
' number of fine neutron groups
  numneutrongroups=56
' fine group to broad group correspondence array
  neutroncollapse
  4r1 4r2 4r3 4r4 4r5 4r6 4r7 4r8 4r9 4r10 4r11 4r12 4r13 4r14
' type of weighting to be used in doing the collapse
  weighttype=zone
  end
end
=paleale
  0$$ 53 e 1$$ 0 1t
end
=shell
  cp ft53f001 ${OUTDIR}
end