International Reactor Dosimetry File 2002 - IAEA Publications

For the convenience of the metrology community, the group form of
IRDF-2002 is also available in the simplified ENDF-like format, in addition to
the pointwise and group files in strict ENDF-6 format. The simplified format
means that all relevant metrology information is available in file MF = 3.
Reaction data that produce a metastable state are normally given in file MF =
10. Conversion of MF = 10 information to MF = 3 data in the metrology file is
accompanied by introducing special MT numbers to prevent confusion.
These special MT numbers for metastable nuclides in file MF = 10 are as
follows:
MT = 292 for (n,2n) reaction products with metastable state in MF = 10;
MT = 291 for (n,n') reaction products with metastable state in MF = 10;
MT = 293 for (n,γ) reaction products with metastable state in MF = 10;
MT = 294 for (n,p) reaction products with metastable state in MF = 10;
MT = 295 for (n,α) reaction products with metastable state in MF = 10.
Another contribution from file MF = 10 is MT = 231 for (n,np) reactions
stored in MF = 10 of the ENDF-6 file.
The pointwise cross-section data were converted to the extended SAND-II
group structure using a flat weighting spectrum. Neutron temperature is 300 K.
Uncertainties are given in the form of covariance matrices for all
metrology reactions. This information is included in the group version as NI
subsection(s) in the file MF = 33.
Originally, the uncertainties were given in the ‘point data’ library for the
Sc-45(n,γ)Sc-46 reaction as a combination of file MF = 32 and MF = 33 data.
File MF = 32 was converted to file MF = 33 format, and this information was
inserted as an extra NI subsection in file MF = 33 of the group version.
108