This post first appeared on the Hudson Institute’s blog Sustaining US Leadership in Nuclear Security. The December 11, 2017 explosion in New York City’s Port Authority was a disruptive, but not devastating, attack. The perpetrator wore a homemade device that he constructed using information found on the Internet. The attack alarmed the public, but there was some solace in the lack of physical damage. This was due to luck, not adequate security. It could have been much worse. What if the terrorist acquired nuclear or radiological materials and constructed a dirty bomb—a weapon that uses a conventional explosive to spew radioactive material, contaminating large areas? This is not a distant threat. Hospitals all over New York City hold blood irradiators, equipment used for blood transfusions. Inside each irradiator sits a capsule with a cesium-137 source, a highly dangerous material that the International Atomic Energy Agency (IAEA) ranks as a Category I source, reserved for the most deadly substances. Despite security concerns, the Nuclear Regulatory Commission guidelines for blood irradiators remain vague. Category I sources can cause radiation poisoning, burns, and death. Despite security concerns, the Nuclear Regulatory Commission guidelines for blood irradiators remain vague. A 2012 GAO report found that most cesium blood irradiators were secured with little more than a simple lock; some were even resting near a bay of unlocked windows. This lack of security is not only concerning, it is inexplicable. If the cesium is removed from the capsule and attached to a conventional explosive, a terrorist could create a dirty bomb with the potential to disrupt society for decades. Of course, a dirty bomb is not like a nuclear bomb when it comes to physical devastation. It is not likely to destroy buildings or spread devastating amounts of radiological material. Nonetheless, the detonation would almost certainly cause mass panic. The public would avoid the area and may question the ability of the authorities to protect them. Commerce in the affected area would collapse and the stock market would likely drop. Further, hundreds of thousands of people who think they could have been exposed would rush to the hospital, overwhelming medical networks and potentially diverting care from those who genuinely need it. A Real Threat This may sound like a scene from an action movie, but real-world examples of radiological damage exist. In 1987, cesium-137 was stolen from an abandoned hospital in Goiania, Brazil. This led to multiple deaths and more than 100,000 people being monitored for adverse effects. Today, if cesium-137 were stolen and used in a dirty bomb, the target—whether it is Port Authority, the Empire State Building, or the U.S. Capitol Building—would become a “no-go” zone for months or even years. The government would pay immense sums to decontaminate the area. That’s why dirty bombs are often referred to as weapons of mass disruption. Fortunately, non-radioactive sources for blood irradiators are readily available. If used globally, the risk of a terrorist acquiring a dirty bomb would be greatly reduced. Other options include x-ray blood irradiators, linear accelerators, and photochemical UV sterilizers. Many other countries have already replaced their cesium irradiators with alternative technologies, with x-ray irradiation proving to be the most popular option. Some Progress There is now an international initiative to replace cesium irradiators. France and Norway have replaced 100 percent of their cesium sources, while Japan has replaced about 80 percent of its stock in the wake of the 2011 Fukushima incident. The United States remains gravely behind on this front, even though the solution would increase U.S. national security with no negative impact on the quality of medical care. There are some reasons that change has been slow. Cesium-137 sources are relatively low-cost and last about 30 years due to their longer half-life, making them ideal for medical facilities. Yet, the facilities that house the irradiators are not required to have insurance. Should there be an incident, the cost of cleanup will fall on the government. Thus, the current situation lacks incentive for change, but budgetary constraints for new technology are not insurmountable. In the long-term, x-ray blood irradiators do not need security and could add to hospital savings. In the short-term, government programs already exist to ease the financial strain of transitioning to a new technology. To facilitate the transition to alternative technology, the Office of Radiological Security at the National Nuclear Security Agency (NNSA) created an initiative to replace 34 cesium irradiators by 2020. The NNSA is offering to remove the radioactive source, saving hospitals an estimated $100,000 – $200,000 per irradiator, and providing assurance that the source is disposed of properly, in addition to paying for half of the new x-ray technology (a cost of about $250,000). While replacing 34 devices is a start to increasing domestic nuclear security, there is still work to be done to replace all 550 cesium blood irradiators in U.S. hospitals. New York City now sits at the forefront of the movement to eradicate cesium-137 blood irradiators, promising to complete the transition to alternative technology by 2020. But more needs to be done. Pennsylvania, Massachusetts, Texas, and California have the highest number of cesium blood irradiators and are at higher risk. They should be encouraged to follow the Big Apple’s lead. The technology that saves lives should not pose a national security threat — and in this case, it does not have to.