Documentation on the URESA Library

    Released: 1998-07-25

    The original data library URES was a continuous-energy neutron library for MCNP that included probability tables to represent unresolved resonances. Room-temperature data for 27 isotopes were provided on URES, based on ENDF/B-VI release 4. ZAIDs for the 27 isotopes ended in .49c.

    After the initial release, processing problems were found for 6 of the isotopes on URES: W-182, W-183, W-184, W-186, Th-232, and U-238. The problems would impact coupled neutron-photon calculations; neutron only problems would not be affected. An updated version of URES, named URESA, was then prepared. For the 6 isotopes listed above, the photon-production data have been deleted and the ZAID's have been changed from .49c to .48c. Users should note that the heating (energy-deposition) data are now inconsistent for these isotopes and should not be used. The other 21 isotopes have simply been copied over intact from URES to URESA and their ZAIDs remain .49c. It is the URESA library that is currently distributed.


    1. "ENDF/B-VI Neutron Library for MCNP with Probability Tables", Little, R.C, (1995), LA-UR-98-5718


    URESA can be downloaded either as a zip file or as a compressed tarball

    • uresa.tgz (sha512 26325c6adaefaca8297dff82fefce682427476e445b3c453110fce72d73f369638494a1bed26c406f2b7182b721c11e393b341cbbae95a2c418f63799a1d8572)
    • (sha512 34b5fb5b49c7ced6f3b8cbb636d5c9421e72aae88223507ce3b34d2b4b9e4a9f36fa12874f03d7dfdee735fd84874024a9dd99be72ffcf663f2505a68968d852)

    If further information is required contact a member of the Data Team by e-mail at