The Department of Homeland Security over the next few years plans to replace around 300 of its Radiation Portal Monitors (RPMs) deployed to the country’s northern and southern borders but for the most part the department the department has found that with proactive maintenance and having spare parts available most of the legacy fleet of stationary radiation detectors can remain operational until at least 2030, the Government Accountability Office (GAO) says in a report earlier this month.
DHS had begun planning two years ago to replace its fleet of nearly 1,400 RPMs as they approached the end of their estimated 13-year life-cycle but as of this fall the detectors are still nearly 100 percent operational and studies of have shown that they can remain operational through 2030 and possibly longer, GAO says in Radiation Portal Monitors: DHS’s Fleet Is Lasting Longer than Expected, and Future Acquisitions Focus on Operational Efficiencies (GAO-17-57). Officials from DHS and the Department of Energy’s Pacific Northwest National Laboratory tell GAO that the RPM fleet could last at least another 20 years.
Now DHS is focused on selected replacement of RPMs—which means either using existing systems that are upgraded with new alarm threshold settings or acquiring enhanced systems available commercially—“to gain operational efficiencies and reduce labor requirements at some ports,” GAO says. Between FY ’16 and FY ’18 DHS plans to replace about 120 RPMS on the northern border with upgraded RPMs, and between FY ’18 and FY ’20 to replace between 150 and 250 RPMs at the southern border with enhanced, commercially available RPMs, the report says.
The DHS Domestic Nuclear Detection Office acquires and deploys RPMs, which in turn are operated by Customs and Border Protection at ports of entry along the U.S. border. The detectors screen cargo and vehicles for the presence of radiation but can’t identify the material that causes an alarm. If there is an alarm, a cargo container or vehicle is directed to a separate area for secondary inspection by a CBP officer who uses a handheld radiation detector to resolve the alarm.
All cargo containers and vehicles entering the U.S. at land border crossing pass through an RPM and nearly 100 percent of cargo containers passing through seaports are scanned by the systems.
Over the years DHS has acquired RPMs from Ludlum Measurements, Inc. and Leidos [LDOS]. Since FY ’02, DHS has bought 1,322 RPMs from Leidos and 384 from Ludlum, most of which were in FY ‘03.
GAO says that the Ludlum RPMs have a design limitation that prevents them from being upgraded with the revised operational settings, which allows the systems to be more finely tuned to threat materials while reducing nuisance alarms triggered by innocuous naturally occurring radiation materials. RPMs upgraded with the revised operational settings have reduced nuisance alarms by 75 percent on average at the sites where the changes were made, the report says.
Without the upgrades, the Ludlum RPMs “do not have the threat discrimination capabilities equal to the upgraded Leidos RPMs,” GAO says.
The report says that DHS plan to replace more than 120 Ludlum RPMs at the northern border with upgraded Leidos systems from existing inventory. GAO says DHS plans to replace between 150 and 250 upgraded Leidos RPMs at the southern border with enhanced, commercially available systems that provide nuisance alarm levels up to 99 percent lower than legacy RPMs.
If nuisance alarms can be lowered by 99 percent, that would enable CBP to conduct remote operations at the sites where the enhanced systems are deployed, freeing up staff resources, GAO says.
DHS currently plans to begin acquiring enhanced RPMs in FY ’18, GAO says.