Guide to Performing Computational Analysis of Criticality Accident Alarm Systems ORNL/TM-2013-211

by Thomas M. Miller, Douglas E. Peplow


This document provides guidance on performing computational analyses of Criticality Accident Alarm Systems (CAAS). A brief overview of ANSI/ANS-8.3-1997 (R2012) [1], the standard that the United States Department of Energy uses to guide the placement of CAAS detectors, is provided with a focus on the parts of the standard that are most applicable to calculating CAAS detector responses and evaluating CAAS detector coverage. This is followed by a brief discussion of how CAAS detector response calculations differ from eigenvalue calculations that criticality safety practitioners perform regularly. The remainder of the document provides computational examples of how to determine the minimum accident of concern according to ANSI/ANS-8.3-1997 (R2012), how to calculate the response of a CAAS detector due to a specific criticality accident, and how to evaluate the coverage of a CAAS detector for criticality accidents. These practical examples are solved applying SCALE 6.1 [2] and MCNP5 [3], but the methodologies can be applied to other radiation transport codes with similar capabilities, including deterministic codes.

Publication Citation

2017 June 2, 2017