Nevertheless, the effectiveness of radiation detection equipment in the maritime environment remains limited.

FORBES: In The Works: New Radiation Monitoring For US Ports

Rare earth elements are also used for military applications, such as advanced optics technologies, radar and radiation detection equipment, and advanced communications systems, according to a 2011 research report by the US Government Accountability Office.

BBC: US to build $120m rare earth research institute

Researchers at Sandia National Laboratories have developed radiation-detection pods that can monitor airborne radiation using drones, without endangering human flight crews.

FORBES: Drones To Be Deployed As Nuclear Fallout Detectors

To date, DNDO has, among other things, tested boat-mounted radiation detectors, detection equipment that can be carried in a backpack, and handheld radiological detection and identification devices that can withstand exposure to water.

FORBES: In The Works: New Radiation Monitoring For US Ports

Chemical and biological sensors already in place on the National Mall will be supplemented with radiological detection equipment, including radiation pagers on the belts of some law enforcement officers.

CNN: Security at record high for WWII Memorial ceremony