Add script for converting Lib80x data

scripts/openmc-convert-lib80x-data

@@ -0,0 +1,99 @@
+#!/usr/bin/env python3
+
+import argparse
+from collections import defaultdict
+import glob
+import os
+
+import openmc.data
+
+
+description = """
+Convert ENDF/B-VIII.0 ACE data from LANL into an HDF5 library
+that can be used by OpenMC. This assumes that you have a directory containing
+subdirectories 'Lib80x' and 'ENDF80SaB'.
+
+"""
+
+
+class CustomFormatter(argparse.ArgumentDefaultsHelpFormatter,
+                      argparse.RawDescriptionHelpFormatter):
+    pass
+
+
+parser = argparse.ArgumentParser(
+    description=description,
+    formatter_class=CustomFormatter
+)
+parser.add_argument('-o', '--output_dir', default='lib80x_hdf5',
+                    help='Directory to create new library in')
+parser.add_argument('--libver', choices=['earliest', 'latest'],
+                    default='earliest', help="Output HDF5 versioning. Use "
+                    "'earliest' for backwards compatibility or 'latest' for "
+                    "performance")
+parser.add_argument('--datadir', help='Directory containing Lib80x and ENDF80SaB',
+                    default=os.curdir)
+args = parser.parse_args()
+assert os.path.isdir(args.datadir)
+
+# Get a list of all ACE files
+lib80x = glob.glob(os.path.join(args.datadir, 'Lib80x', '**', '*.80?nc'), recursive=True)
+lib80sab = glob.glob(os.path.join(args.datadir, 'ENDF80SaB', '**', '*.??t'), recursive=True)
+
+# Find and fix B10 ACE files
+b10files = glob.glob(os.path.join(args.datadir, 'Lib80x', '**', '5010.80?nc'), recursive=True)
+nxs1_position = 523
+for filename in b10files:
+    with open(filename, 'r+') as fh:
+        # Read NXS(1)
+        fh.seek(nxs1_position)
+        nxs1 = int(fh.read(5))
+
+        # Increase length to match actual length of XSS, but make sure this
+        # isn't done twice by checking the current length
+        if nxs1 < 86870:
+            fh.seek(nxs1_position)
+            fh.write(str(nxs1 + 53))
+
+# Group together tables for the same nuclide
+suffixes = defaultdict(list)
+for filename in sorted(lib80x + lib80sab):
+    dirname, basename = os.path.split(filename)
+    zaid, xs = basename.split('.')
+    suffixes[os.path.join(dirname, zaid)].append(xs)
+
+# Create output directory if it doesn't exist
+if not os.path.isdir(args.output_dir):
+    os.mkdir(args.output_dir)
+
+library = openmc.data.DataLibrary()
+
+for basename, xs_list in sorted(suffixes.items()):
+    # Convert first temperature for the table
+    filename = '.'.join((basename, xs_list[0]))
+    print('Converting: ' + filename)
+    if filename.endswith('t'):
+        data = openmc.data.ThermalScattering.from_ace(filename)
+    else:
+        data = openmc.data.IncidentNeutron.from_ace(filename, 'mcnp')
+
+    # For each higher temperature, add cross sections to the existing table
+    for xs in xs_list[1:]:
+        filename = '.'.join((basename, xs))
+        print('Adding: ' + filename)
+        if filename.endswith('t'):
+            data.add_temperature_from_ace(filename)
+        else:
+            data.add_temperature_from_ace(filename, 'mcnp')
+
+    # Export HDF5 file
+    h5_file = os.path.join(args.output_dir, data.name + '.h5')
+    print('Writing {}...'.format(h5_file))
+    data.export_to_hdf5(h5_file, 'w', libver=args.libver)
+
+    # Register with library
+    library.register_file(h5_file)
+
+# Write cross_sections.xml
+libpath = os.path.join(args.output_dir, 'cross_sections.xml')
+library.export_to_xml(libpath)