Preliminary Evaluation of Effluent Radioactivity Monitoring Systems for BWR (Boiling Water Reactor) Plants.

摘要

The need for upgrading the effluent monitoring systems at commercial nuclear power plants was recognized following the TMI-2 accident in 1979 (NUREG-0737 Clarification of TMI Action Plan Requirements). The report discusses some of the generic issues associated with the transport and subsequent sampling of noble gases, particulates, and iodine species that utilities must consider to ensure accurate reporting during severe accident conditions. In light of these generic concerns, a specific postaccident upgrade is discussed, major measurement uncertainties are identified, and recommendations are made. The focus of these recommendations is the transport behavior of iodine; sample-line losses may result in an order of magnitude error for near-real-time measurements. Finally, a recommendation for a laboratory sample-line test program is made.