There were dirty bomb ingredients in ISIS-controlled Mosul

The Institute’s researchers estimated, based on open source information, that the cobalt 60 had decayed considerably but still had a radioactive strength which would place it in the International Atomic Energy Agency’s (IAEA’s) category 2 of radioactive sources, described as “very dangerous to the person” (IAEA, “Categorization of Radioactive Sources,” Vienna, 2005). In terms of dose strength, the sources could produce a fatal dose to an individual at a meter from the source within 2-4 hours. For individuals within 0.1 meter distance, it could occur within 2-3 minutes.

In comparison, a widely publicly discussed radioactive iridium source that went missing in Iraq in late 2015 was also category 2 (the source was later found and secured. See: “Exclusive: Radioactive material stolen in Iraq raises security concerns,” Reuters, 17 February 2016). However, the researchers estimated that at least one of the cobalt-60 sources in Mosul had a dose rate roughly twenty times greater than the missing iridium.

Lessons
The Institute says that this case has several lessons for the future, and should serve as a reminder of the risks posed by radioactive sources, many of which are poorly protected or accounted for.

It is not clear why DAESH did not use the cobalt 60 sources to make a radiological dispersal device. The researchers’ speculations include that since the cobalt 60 comes in metal form and not as a powder, it would be more difficult to use the radioactive cobalt, involving steps that can be very dangerous for unprepared and inexperienced individuals. A more likely possibility is that DAESH did not know about the cobalt 60 sources. Did courageous hospital and university staff work successfully to keep the existence of the sources secret?

Other potential reasons for the lack of use include

— The sources were judged as not destructive enough for DAESH goals;
— The use of the sources in a radiological dispersal device in the West did not fit the DAESH idea of how they would want to attack the West; or
— The DAESH leadership was preoccupied elsewhere and did not learn about the sources in Mosul or have a chance to think through the opportunities offered by the cobalt 60 sources.

“Whatever the actual case, we are relieved that these dangerous sources remained intact and were not seized by Daesh. We may not be so fortunate next time. It is important to learn from this near miss and seek improvements to further reduce the chances of a terrorist group misusing radioactive materials,” the Institute says.

The Institute says that this case should lead to reinvigorated efforts to inventory and adequately protect radioactive sources throughout the world. However, as this case highlights, improving physical protection may not be enough. It is also important for the United States and its allies to accelerate programs to identify, consolidate, and remove dangerous radioactive sources, particularly in regions of tension or where terrorists are active. “Iraq and other countries in regions of instability and insurgency should receive expedited assistance to remove cobalt 60 sources and receive cobalt-free cancer treatment mechanisms,” the Institute concludes.

— Read more in Joby Warrick and Loveday Morris, “How ISIS nearly stumbled on the ingredients for a ‘dirty bomb’,” Washington Post (22 July 2017)