Identifying a Problem
Radiation screening portal monitors are one of the first lines of defense in protecting people and facilities from the spread of radioactive material. They are widely used in nuclear power plants, event security applications, customs and border crossings, as well as radiological emergency scenarios to scan pedestrians or vehicles for radiation.
Typical portal monitors, however, have a hard time distinguishing between radioactive materials passing through the portal, and radioactive materials present nearby but outside the portal. Radiation detectors measure a response regardless of where the radiation originates. This fact leads to the potential for numerous false alarm conditions in the course of normal operation, which erodes confidence in the product. This can create either confusion or complacency for operators of a radiation security checkpoint.