A U.S. government watchdog group is worried that one of Washington’s nuclear agencies isn’t doing enough to study and prevent the economic impact of a nuclear dirty bomb.

The September 30th report comes from the Government Accountability Office, a nonpartisan group that studies various issues for Congress. In its report the GAO called out the Nuclear Regulatory Commission, saying it “has not taken steps to address certain radiological security risks.”

The NRC is the part of the federal government that oversees nuclear waste, regulates radiological material, and oversees reactor safety. And what, according to the GAO, was the Commission’s great sin? “NRC has not taken actions to incorporate consideration of socioeconomic consequences into its regulations,” the report said.

A dirty bomb is a rare thing, so rare in fact that they’ve never been used in a war. The concept is that someone attaches an explosive to radioactive material. When the bomb goes off it spreads the radioactive material, poisons an area, and kills people. A dirty bomb isn’t comparable, in any way, to a nuclear weapon. Most experts agree that the bulk of the damage would come from the initial blast and not the radioactive material itself.

In the popular imagination, a dirty bomb would send radioactive particles high into the air where the wind would disperse them throughout a large area. In reality, most radioactive material is so heavy that it doesn’t travel very far. From 2010 to 2014, Israel detonated a series of dirty bombs in the desert near the Dimona nuclear reactor.

Israel said it was conducting the tests as a defensive measure in order to practice cleanup and get an idea of what its effects would be. They weren’t great. Israel detonated 20 different bombs that included a payload of 99mTc, a common radioactive substance used in medical imaging. The particles didn’t spread far.

Despite the incredible rarity and unlikelihood of a dirty bomb, America became obsessed with it after 9/11. If terrorists could slip into the country and fly planes into the World Trade Center, wouldn’t it be possible for them to steal some radioactive material from a hospital and build a dirty bomb?

In the decades after 9/11, many government agencies got serious about shoring up shortcomings around security and regulations regarding nuclear materials. According to the GAO, however, the NRC hasn’t kept up. “NRC has not implemented 11 out of 18 actions we have recommended since 2012,” the report said. “NRC has not taken action to consider socioeconomic consequences in its decision-making criteria for determining security requirements for radioactive materials.”

The report constantly reminded the reader that dirty bombs are bad for business. “Several studies…43 radiological experts we previously convened, officials we interviewed for this report, and the NRC-led Task Force all agree—and recent events corroborate—that the socioeconomic consequences from a dirty bomb would be severe,” it said. “For example, in 2017 and 2018, Sandia National Laboratories estimated that a dirty bomb…could cause an estimated $24 to $30 billion in damages and economic losses, most of which would be socioeconomic.”

As evidence of the real-life impact of this dirty bomb fear, the GAO pointed to an incident that had nothing at all to do with explosives. In 2019, a government contractor pierced a medical device containing cesium-137 at the University of Washington. This was an industrial accident, not a dirty bomb, but—according to the GAO—the economic impact was severe.

“Over 80 research programs valued in the tens of millions of dollars were affected, and over 200 researchers and laboratory staff had to be relocated,” the GAO said. “Several researchers could not find replacement laboratories to host their research and were compelled to seek employment elsewhere. NNSA estimated the total cost of the incident—including cleanup, remediation, reconstruction, and other costs—to be $156 million.”

Thirteen people were exposed during this accident and had to be decontaminated. “Though not a dirty bomb, and not an uninsured incident, the accident illustrates the costs that can result from the release of even a small quantity of material,” the GAO said in a 2021 report on the incident.