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Radiation Detection Standards for Homeland Security

After the September 11, 2001, attacks, the fear that nuclear materials could be smuggled in one of the millions of storage containers that arrive in the U.S. over land and by sea became more pronounced. To protect the country from this danger, new technologies were needed, in particular, instruments for detecting nuclear and radiation-based threats. The radiation detection instrumentation available at that time was not built for post-9/11 homeland security needs, so standards had to be developed to support the development of new instruments with the required capabilities.

Woman standing in a lab holds a rectangular radiation detector near a metal globe that has been painted with a radiation symbol
Physicist Leticia Pibida uses a handheld radiation detector like those officers use at ports of entry to the U.S. to scan a radiological test source. 
Credit: M. Esser/NIST

Researchers in Building 245 built standard gamma ray and neutron sources, which emit a carefully calibrated flow of radiation of the type that would be given off by potential weapons. These sources were then used by industry to make sure their new instruments were detecting the correct amounts of radiation. The steady flow of radiation from these sources is also used to ensure that detection devices work properly and effectively in the field. Detectors calibrated with NIST standards are not only operated at ports of entry, but also made available to first responders in case the need should ever arise for them to deal with a nuclear terrorism event. 

Since work began in 2002, NIST researchers have developed and published approximately 20 national and international standards for homeland security applications.

A semi truck shown head-on between tall yellow detectors
Truck shown passing through radiation portal monitors that detect hidden radioactive sources
Credit: DOE National Nuclear Security Administration
Created July 29, 2019, Updated September 20, 2019