Scope@ purpose@ and application This standard provides a procedure for the evaluation of the best-estimate fast (E > 1.0 MeV) neutron f luence in the annular region between the core and the inside surface of the vessel@ through the pressure vessel and the reactor cavity@ between the top and bottom of the active fuel given the neutron source in the core. This evaluation employs both fast neutron flux computations and measurement data from invessel and cavity dosimetry@ as appropriate. The standard applies to both U.S.-designed pressurized water reactors ~PWRs! and boiling water reactors (BWRs)