Updated 8:58 a.m.
A new utility industry study out Tuesday says an electromagnetic pulse triggered by a high-altitude nuclear explosion would threaten the nation's electric grid, but might not bring the kind of widespread and prolonged power outages sometimes predicted.
The three-year study by the Electric Power Research Institute looked at how an electromagnetic pulse, or EMP, might affect the nation's electric grid. Its publication comes just weeks after President Trump issued an executive order warning that an EMP could affect global commerce and stability and disrupt national security and economic prosperity.
Those kind of warnings have become the stuff of political debates. A 2017 Congressional report warned about the threat, and much of the current political rhetoric focuses on a potential attack from North Korea.
But EPRI CEO Michael Howard said the study was designed to bring hard research to the politics.
"We started this study to really understand the facts, not the science fiction, but the facts," Howard said. "To really understand the facts, you have to do mathematical modeling, you have to do laboratory testing."
The institute's engineers did those tests at laboratories in Charlotte, Knoxville, Tennessee and other sites, in collaboration with utilities and researchers at federal laboratories. They found, among other things, that an attack could trigger multi-state power outages similar to a major hurricane - but not a nationwide grid failure.
Report co-author Randy Horton said an electromagnetic pulse could lead to a "regional voltage collapse."
"Think of that as something like on the order of the 2003 blackout. But one of the primary things we found is that you would not have widespread transformer damage," he said.
EFFECTS OF AN EMP
Horton says an EMP is actually a series of three pulses that could affect power lines and the equipment that controls them. First an initial short pulse, an intermediate pulse similar to lightning, and a third pulse not unlike the effects of a solar flare.
Horton and his colleagues say protective measures already in place likely would minimize risk. So would relatively inexpensive tactics still being studied - such as adopting new kinds of shielding and fiber-optic cabling, additional electrical grounding and surge suppressors, and metal structures to house network equipment.
But how likely is such an attack and how much should utilities spend to get ready for it? None of the EPRI researchers wanted to say how likely they thought an attack might be.
Catherine Butler of Duke Energy said the company considers an electromagnetic pulse just one of many threats it needs to prepare for.
"So that can be electromagnetic pulses, it can be cyber-security, it can be storm hardening. All of those types of things are really important to our customers, our company and to our shareholders," Butler said.
She said the company is already using some of the tactics outlined in the EPRI report.
For utilities, whether and how to prepare for an EMP is a risk-management calculation. Other utility executives briefed on the report this week say it will help them with planning.
Mark McCullough oversees power transmission for American Electric Power, an 11-state utility based in Columbus, Ohio.
"We really like what EPRI's doing, because it's going to allow us options to mitigate the risk at hopefully lower and lower costs and minimize the impact to our customers," McCullough said.
READ THE FULL REPORT
The full report is available online Tuesday morning, at EPRI.com.
This story has been update to correct the description of the pulses in an electromagnetic attack.