Mobile Radiation Portal Monitors (RPM)

A mobile Radiation Portal Monitor (RPM) is a truck-mounted RPM system designed to detect nuclear materials in cargo containers. The mobile RPM is appropriate for seaport, rail, airport, and vehicle cargo applications, though the mobile RMP is mostly used by Customs and Border Patrol (CBP) at seaports while stationary RPM is used at land borders. The system is designed to examine cargo in shipping containers and can operate in stationary mode, with cargo passing between a pair of mobile RPMs, or in mobile mode, driving past stationary objects. The primary focus of the mobile RPM is to detect and interdict illicit radiological materials at ports of entry.

A mobile RPM system consists of a truck equipped with two detection panels mounted on the truck chassis. The systems are totally passive and do not emit any radiation themselves. The detection panels contain both gamma and neutron sensors that can detect plutonium, highly enriched uranium, and radioisotopes emanating from nuclear devices, dirty bombs, special nuclear materials and isotopes used in medicine and industry. The system can inspect areas ranging from close to the ground to several feet in the air, with no gap in detector coverage in between. Reflective presence sensors are used to trigger RPM measurements. Speed and distance detectors are part of the system's ancillary equipment. On-board computers analyze, display, and record information within easy reach of the vehicle operator and facilitate communication with the base of operations.

In April 2006, it was widely announced that the Department of Homeland Security signed a $20 million contract with defense contractor Burtek, Inc. to provide 200 of those detectors. The first of the trucks was deployed at the Port of New York/New Jersey in early May, and additional devices would soon appear at ports across the country. The portal monitors are manufactured by Science Applications International Corporation/Exploranium; the commercial trucks are manufactured by Ford Motor Company; and Burtek Inc. designed and assembled the completed vehicle.

While CBP already employs the use of stationary RPM, According to Burtek, key benefits of mobile RMP include:

• Safe environment for operators
• Rapid deployment and setup
• Effective detection of radiological materials
• One- or two-person operation (depending on the amount of cargo to be screened in a day)
• Easily redeployed to new locations, or to deal with temporary screening or peak demand
• Adaptable to existing port operations; does not require operational changes
• Cost-effective screening for low-volume, multiple locations
• The technology is the same as CBP already employs at several busy border crossings, but is adapted to be mobile enough to be placed on a truck.