At a hospital in a major US city, medical equipment used to sterilise blood with radioactive caesium-137 is secured in room with a sturdy padlock on the door. And the lock's combination is written on the door frame.
That was only one of the glaring security oversights inspectors found at medical facilities that store radioactive equipment across the United States, according to a US Government Accountability Office report. The US stockpile of radioactive material, it would seem, is far from secure.
When world leaders gathered in Washington for the inaugural Nuclear Security Summit in 2010, US President Barack Obama led talks on how to reduce the risk of nuclear terrorism. This is again the main focus as leaders gather in Seoul this week for another nuclear summit that concludes today.
Unlike in 2010, leaders have another, equally challenging item on the agenda: how to secure radiological sources that could be used in a "dirty bomb". And as the examples discovered by the GAO make clear, not even Washington - a leading advocate for radiological safety - has a foolproof strategy.
Part of the reason is the sheer quantity of radioactive material. Unlike weapons-grade fissile material, which is possessed by only a few countries and stored under tight military controls, devices that use radioactive isotopes have civilian applications ranging from medical research to food sterilisation in every country around the globe. Despite regulations present in every country, there are countless opportunities for devices to go missing.
And they do. Between January 1993 and December 2011, there were nearly 2,200 incidents of loss, theft or improper disposal of nuclear and other radioactive material reported to the International Atomic Energy Agency. One such device was lost in the UAE last year, before it was recovered without incident two weeks later.
Many more devices worldwide are not recovered. In the United States alone, an estimated 200 devices are lost or misplaced each year. In theory, it should be easy for a determined terrorist to acquire radioactive material, strap it with conventional explosives and light a charge. In practice, however, it hasn't happened.
US diplomatic cables leaked last year outlined an Al Qaeda plot to launch a "dirty radiological IED" programme. In 2002, Jose Padilla, a US citizen, was arrested in connection to an Al Qaeda attempt to build and detonate a dirty bomb. And in 2006, British citizen Dhiren Barot was convicted of a similar Al Qaeda plot.
Neither Padilla nor Barot came close to producing and deploying a weapon, however. The only recorded deaths attributed to the misuse of a commercially available radiological device were accidental. In 1987, an improperly discarded medical device containing a large amount of caesium-137 killed four people in Brazil's Goiania region and injured hundreds. The clean-up cost, adjusted for inflation, was about $36 million (Dh132 million).
As the incident demonstrates, the most prevalent risk from civilian radiological devices may be accidents, both in terms of fatalities and economics.
But that does not mean that terrorism can be discounted. Graham Allison, a former nuclear-security adviser to President Ronald Reagan and director of the Belfer Center at Harvard University, says that it would be "relatively simple" to construct a radiological weapon. Such a weapon would not cause a nuclear explosion, and would not have nearly the same lethality.
Rather, Dr Allison says, it would "spread radioactive material and its damage would be primarily economic and psychological".
Togzhan Kassenova, an associate in the nuclear policy programme at the Carnegie Endowment for International Peace in Washington, says it is this threat that faces smaller countries with developing economies and a limited ability to police, monitor and control radiological material. "It is the developing countries that are especially keen to discuss radiological security at the summit," she says, "because in their view a threat of radiological terrorism is more immediate than a threat of nuclear terrorism."
High-level diplomacy can help focus attention, but it can't solve every challenge. In every country, including the UAE, there are laws that govern the use and possession of radiological substances. In most countries, however, the problem is enforcement.
There are proposals being circulated in Seoul to limit the risk of radiological terrorism. But the biggest hurdle to overcome may be a lack of inter-governmental cooperation. Nuclear non-proliferation experts have urged world leaders to devote more financial resources to the challenge and to improve information sharing across borders.
The UAE has an opportunity to be a model in this regard. The Federal Authority for Nuclear Regulation, the nation's two-year-old regulator, has issued 428 licences for the use and operation of regulated radioactive material. The trouble, agency spokesman Ayhan Evrensel says, is that the regulator does not have the legal authority to issue fines for failure to comply. The agency is working on a regulatory framework, but the lack of punitive fines means FANR has few tools to punish offenders. The agency needs this legal authority immediately.
Washington has led the way on nuclear terrorism. South Korea has focused on the risk of radiological sabotage. It is now up to countries including the UAE to devise enforcement mechanisms to prevent this material from falling into the wrong hands.
On Twitter: @gregcbruno