The Homeland Security Department is trying to ramp up wearable devices that can detect nuclear radiation.

DHS has made a handful of awards for well-developed prototypes, of wearable products from companies including Leidos and Physical Sciences, Inc., according to a recent FBO posting.

Last year, DHS made a broad agency announcement soliciting proposals for so-called Wearable Intelligent Nuclear Detection, or WIND, technology. Employees would wear the products to ensure nuclear devices weren't secretly being transported in areas like marine vessels, metro systems, or other public areas, according to DHS.

DHS was specifically searching for "advanced technology demonstrations," which are for "mature prototype capable of providing reliable performance measurements in a challenging and realistic, albeit simulated, operational environment," the BAA said. Awards were for roughly $4 million to $5 million.

DHS' Domestic Nuclear Detection Office, whose mission is to protect the U.S. from nuclear devices, was specifically searching for a modular wearable system that could sense, localize and identify nuclear particles, including gamma rays and neutrons.

The office also wanted detection units that weighed less than 22 pounds, which is roughly the weight of current detection systems, the BAA said. Technology with "reconfigurable components" to fit various use cases would also be ideal.

The BAA noted DHS is looking for both hardware and software—including advanced algorithms—that could help map the area around a device, highlighting "spatial correlations" in the data each wearable piece collects and relays back to a central hub.

Last year, DNDO awarded a contract for a "human portable tripwire"—Customs and Border Protection, Transportation Security Administration and Coast Guard officers would be equipped with wearable radiation detectors that "passively monitor the environment and alert the user when nuclear or other radioactive material is present."