Early Triage for Radiological and Nuclear Events
ISR led the (R&D) project, Early Triage for Radiological and Nuclear Events (ETRNE), that was based on the concept that in any radiological/nuclear (RN) event involving the release of radioactive material, it is vitally important to determine whether or not casualties have been internally contaminated. This project, funded by the Centre for Security Science (CSS), developed a protocol, through modeling, scientific testing and experimentation, that allows responders and receivers to use their existing hand-held radiation detectors to rapidly screen casualties of an RN event for internal contamination. Detector specific protocols were developed based on screening criteria calculated from Monte Carlo N Particle (MCNP) transport code simulations and laboratory experiment that considered the biokinetics of internal contamination.
The ETRNE work consisted of computer simulation and laboratory experimental efforts to develop internal contamination calibration factors for selected hand-held detectors. Models of the hand-held detectors were developed in Monte Carlo N Particle (MCNP) radiation transport code. Detector measurement efficiency simulations were performed for Bottle Mannequin Absorber (BOMAB) phantoms homogenously filled with a mono-isotopic radioactive solution. The measurement efficiency simulations were benchmarked and validated with measurements of BOMAB phantoms in the Human Monitoring Laboratory at Health Canada.
The effect of biokinetics was studied to assess the effect on the detector measurement efficiencies. Dose and Risk Calculation (DCAL) software was used to model the time-dependent retention of the initial intake and distribution of the retained radioactive material in the body. The distribution of the intake in the various bodily compartments defined by DCAL was ported into an MCNP input file for the ICRP 110 reference male voxel phantom. Time-dependent detector efficiency models were developed for each hand-held radiation detector used in this study.
Internal Radiological Contamination Screening protocols (the “Protocols”) were developed for each hand-held detector. Conservative simplifications regarding the intake parameters (e.g., time of intake, intake pathway, etc.) were applied to make the Protocols manageable for in-field applications. A set of screening criteria were developed for each detector. The screening criteria were based on the displayed detector reading. Using the Protocol for their specific hand-held radiation detector, responders and receivers can prioritize patients for internal contamination treatment based solely on the displayed detector reading.