Optimization of a Gaseous Effluent Stack Monitor to measure IPF´s emissions

M. DI TADA, R. REY, M. NUÑEZ Y E. NASSIF

Strassoldo

Workshop; Workshop on the Signatures of Medical and Industrial Isotope Production (WOSMIP III); 2012

Pacific Northwest National Laboratory y Comprehensive Nuclear-Test-Ban Treaty Organization

Usually, stack effluent monitors design is based on requirements for the supervision of medium and low range activity concentration releases from Research Reactors (RR) and Nuclear Power Plants (NPP). When dealing with monitoring of Isotopes Production Facilities (IPF), some specific considerations in the design have to be taken into account. Residence times, detection volumes and their geometries, retention filters and type of information reported are among the variables considered for design. Tracking of specific isotopes (131I, 133Xe,135Xe) is also a possible design requirement.Though the final functional purpose may be similar when monitoring releases form RR, NPP and IPF, there are requirements specifically related to diverse information in the case of monitors that measure emissions of IPF. High activity concentrations levels as those involved in IPF´s emissions impose different design conditions. Interferences between channels may be critical. Detection geometries have to match sampling conditions in order to obtain reliable information. Therefore, a gaseous effluent monitor that is already operating reliably in a RR has to undergo a process of upgrading when the aim is to use it to measure emissions of a IPF. Relevant issues to be taken into account when adapting a RR gaseous effluent monitor to an IPF are discussed, results of MCNP simulations and experimental measurements are presented in this paper.