How Airports Catch Radiation Sources

At the end of 2022, a package contaminated with uranium was found at Heathrow Airport. Responding to this event, Wired editors published an article on methods for detecting radiation sources at airports. Due to the importance of this topic, editors have republished this material.

Radioactive materials can be detected at airports through different forms of monitoring. Covert detectors hidden in the walls at airports silently scan passengers. Customs officials measure the level of radiation using portable devices and drones, loaded with sensors, can fly across wide areas while searching for lost radioactive sources.

British ports of entry screen for all kinds of radioactive substances. However, members of the public often don’t realize that some airports are able to detect even tiny amounts of radioactivity in buildings or cargo-processing areas. 

Marco Panniello, sales director for Arktis, a company that makes radiation-detection devices and supplies them, in particular, to airports, says that systems are completely invisible to the public, since they can be easily covered by advertisements or canvas. The detection devices can be used alongside X-ray machines at airport security areas or hidden in the walls of terminal buildings. They can also be installed in doorways or used in luggage-handling locations.

The Arktis detection devices differ from Geiger counters, which work based on the internal gas amplification principle. Special material inside the Arktis’ devices reacts when it is exposed to the subatomic particles emitted by radioactive substances. This reaction produces a tiny amount of light—scintillation—which is measured by sensors and subsequently processed by computer algorithms. Because different radioactive substances prompt distinct emissions of light, it is often possible to tell immediately what kind of material has been detected—an isotope of uranium or cobalt, for example. Notifications from these devices can be integrated into security systems so staff receives automated alerts on their smartphones when radioactivity is found nearby.

From smoke alarms and other industrial gauges to medical teletherapy machines, there are many examples of objects and devices that contain radioactive material.

A report published last year by Zenobia Homan, who is at King’s College London, and colleagues noted the challenges some South Asian countries face, for example, in ensuring careful disposal of radioactive substances. She says that there are people who hunt for this specifically, they might try and steal it, or smuggle it to sell the material. In May 2021, investigators discovered a scrap dealer in India who had reportedly collected 7 kg of uranium. Officials arrested two men who had allegedly been trying to sell the uranium online.

When radioactive matter is not safely and properly disposed, the consequences can be chilling. Take the Goiânia accident in 1987.  Then two scrap metal collectors found an abandoned radiation source – a metal capsule of a radiotherapy unit in an abandoned radiotherapy institute and sold it to a scrapyard. Owner of the scrapyard, Devar Ferreira, cut this capsule and found a glowing blue powder inside it – radioactive caesium-137 chloride. Unaware of the hazard, the Devar Ferreira’s brother took some of the caesium home, where his six-year-old daughter played with the powder, painting it on her face. She died a month later. The Devar Ferreira’s wife was the first to realize the potential hazard and took the capsule to the hospital, where it was deemed hazardous. In addition to the scrapyard owner’s family, about 250 were contaminated in the incident.

A similar incident occurred in Ukraine. In the late 1970s, in the Karanskyi pit, Donetsk region, where gravel and crushed stone were mined, a radiation source was lost – a capsule with caesium-137, which was used in a radioisotope level meter. Crushed stone from this pit was used for construction and thus got first in concrete, and then in the wall of a residential building in Kramatorsk. In the period from 1980 to 1989, 6 people (4 children and 2 adults) died as a result of radiation exposure over 9 years, and another 17 people were recognized disabled.

That is why it is important to timely detect and properly dispose radiation sources.

Zenobia Homan and Bahram Ghiassee from the Henry Jackson Society, an analytical center that focuses on anti-extremism, note that international regulations and monitoring protocols for radioactive materials have improved greatly over time, especially at national borders. However, according to Ghiassee, certain countries still don’t have the capabilities to detect the movement of radioactive and nuclear material across borders.

According to the Wired