Automated Method for Determining the Areas Covered by Gamma Sensitive Criticality Detectors

摘要

A description of the computer program LOCAS is given. LOCAS was developed at the Hanford site to assist in evaluating what areas in a facility are covered by the gamma-sensitive criticality detectors for various alarm trip settings. Detectors may be grouped into ''2 of n'' sets, and there may be multiple sets. Representations of facility walls are stored in a wall library file, and detector coordinates may also be stored in a library file. Program output consists of numerical tables of dose rates and/or printhead graphics with print characters representing dose rates in a user-defined search plane. The primary limitations of the code are: the assumed photon spectrum is that of prompt gammas from fission, without including the effect of neutron interactions, which tend to produce higher energy photons, and limited inclusion of photon scattering through the use of dose buildup factors. For the purpose of evaluating the areas covered by a detector set, these limitations are conservative, i.e., they tend to underestimate the areas covered by the detection system. 5 refs., 2 figs., 1 tab. (ERA citation 14:003310)