Well, if you happen to have medical equipment lying around nearby with a cobalt source inside versus not having a pile of ANFO components, and people willing to risk death for the cause, making the dirty bomb might be more convenient than making an Oklahoma city type bomb - which is actually a pretty large object, requiring a van. I don’t know if a dirty bomb would be a much smaller object.
It’s like the difference between using a car for a suicide bomb vs. using an airplane as a bomb. Cars are a LOT easier to obtain, but equally clearly both systems have been used. I don’t expect dirty bombs to be used frequently, but they certainly are a possibility these days.
Yeah. Say the bad guys figure out how to operate the controls to get the cobalt-60 source from at the bottom of the tube to up in the radiotherapy machine. They then crowbar open the shutters or something. Now, they literally have minutes for someone to grab the source and somehow cram it into some explosives. Then that person keels over and dies, but maybe they have the explosives behind some crude shielding (sandbags or water barrels or something) on a truck.
They drive the truck bomb to some people they don’t like. Boom. A truck bomb can kill 50+ people routinely.
Unless they did some design work, and arranged the explosives just so, and maybe ground the cobalt-60 rod into powder somehow with a disposable suicide squad…I think the bomb would go off, a couple big chunks of C-60 would land somewhere, and maybe a few people who happened to blunder across the C-60 pieces would get sick.
The only way it would kill more than a few people would be if no one checked with geiger counters.
As I mentioned in a post above, I suspect that a group like IS would expend at least two suicide attackers doing a dirty bombing when it would take only one with conventional. That is, you’d lose at least one guy loading the cobalt source into the bomb, and one guy driving the truck with the suicide bomb. Or you could expend 2 people driving two separate trucks. When you think about it, a second truck bomb would probably kill a lot more people in total than a dirty one.
Those guys might be raghead nutjobs, but I would suspect they are capable of basic logistics planning (they must have, or their humvees wouldn’t be running) and basic consideration between alternatives.
There would be ways to get medical isotopes without killing the person handling them. They’ve got short enough half-lives that it’s impractical to stockpile them for long, so you need to be able to make more, which is usually done using an on-site particle accelerator. You then need to transport the material somehow from the accelerator to the therapy site, and they have equipment to do this safely.
It would be interesting to know what medical radioactive materials they stumbled upon. I used to work in a nuclear pharmacy, and everything we produced was for injection or ingestion, and had a half life of about six hours. It was significantly less dangerous than a sunny day outside or making a Don Miguel burrito in the Stop n Shop microwave.
Cobalt-60 seems to a common culprit, it has a long enough half life to remain dangerous. According to a quick google it seems to be used for external beam radiotherapy and sterilization.