A radioactive “dirty bomb” or radiological dispersal device (RDD), made by combining radioactive material with conventional explosives to spread it, would not cause catastrophic levels of death and injury on the scale of a nuclear weapon detonation. A dirty bomb explosion could cause significant short-and long-term health problems for those in the area and could leave billions of dollars in damage due to the costs of evacuation, relocation and cleanup. Buildings would have to be demolished and debris removed. Access to a contaminated area could be limited for years, as a site is cleaned well enough to meet environmental standards for protecting the public against harmful gamma rays that could penetrate human skin and potentially cause cellular damage.
Sources Are Widespread and Vulnerable
According to the International Atomic Energy Agency (IAEA), "millions of radioactive sources have been distributed worldwide over the past 50 years." They are dispersed across thousands of commercial, industrial, medical and research sites in more than 100 countries, and many of them are poorly secured, particularly during transport when they are vulnerable to theft.
In fact, the same isotopes used for life-saving blood transfusions and cancer treatments in hospitals around the world— such as cesium-137, cobalt-60 and iridium-192—could be used to build a bomb.
Many medical, commercial and industrial groups that handle these materials are ill-equipped to secure them, and a lack of regulatory controls in many countries has led to thousands of missing or stolen radiological sources. A study by the James Martin Center for Nonproliferation Studies found an alarming 170 incidents where nuclear or radiological material was lost, stolen or outside regulatory control in 2014 alone.
A malicious release of radiation at a nuclear power plant or research facility also poses and threat and could cause damage on a similar scale to that caused during the 2011 disaster at the Fukushima Daiichi nuclear power plant in Japan. An attack that deliberately disrupts or damages a nuclear facility—through a physical attack, a cyber attack, or a combination—could result in the release of radiation that would sicken those living in the area and cause significant environmental and economic damage. The 2018 NTI Nuclear Security Index
https://www.ntiindex.org/found that many developing countries considering pursuing nuclear energy programs do not have needed measures in place to properly protect nuclear facilities from sabotage.