ANSI/ANS 19.10-2009

This standard provides a procedure for the evaluation of the best-estimate fast (E 1.0 MeV) neutron fluence 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 bot-tom of the active fuel given the neutron source in the core. This evaluation employs both fast neutron flux computations and measurement data from in-vessel and cavity dosimetry, as appropriate. The standard applies to both U.S.-designed pressurized water reactors (PWRs) and boiling water reactors (BWRs).