By Janet Raloff

Web edition: July 23, 2009

Enlarge

EMP Hit Zone

Altitude determines EMP zone where peak fields can reach 50,000 volts. Blast above dark spot, 62 miles up, yields ground-effects zone within inner circle; outer circle is effects zone for a blast 330 miles up.

Credit: Defense Nuclear Agency

Electromagnetic pulse is hardly a household term. But perhaps it should be. Every computer we buy, every system we turn over to computer control, every device that relies on electronic components — all cars, TVs and phones, for instance — makes us more vulnerable to such a high-energy rain of electrons.

EMP is a powerful and potentially devastating form of electromagnetic "fallout." It’s usually associated with nuclear weapons, although it can be triggered by any major explosive bursts. Unlike radioactive fallout, this rain won’t directly harm living things. It will just catastrophically fry all electronics and modern electrical systems by inducing staggeringly large and rapid current or voltage surges.

It makes a great equalizer for small nations looking to stand up to military Goliaths, argues Rep. Roscoe Bartlett (Rep.-Md.), a former research scientist and engineer who has worked in the past on projects for NASA and the military. All one needs to wreak some serious EMP damage, he charges, is a sea-worthy steamer, $100,000 to buy a scud-missile launcher, and a crude nuclear weapon. Then fling the device high into the air and detonate its warhead.

Such a system might not paralyze the entire United States, he concedes. ”But you could shut down all of New England. And if you missed by 100 miles, it’s as good as a bulls-eye.”

Bartlett brought up questions about the power industry’s vulnerability to EMPs this morning at a House Science subcommittee hearing convened to look at what’s needed to roll out a nationwide “smart grid.” Emerging sensor-driven systems would allow the U.S. power-distribution system to converse back and forth with any devices we plug into it.

A smart grid should, among other things, allow our dishwasher, air conditioner, clothes drier or office lighting to know when the regional demand for power is highest, forcing a need for extra — and higher-cost per kilowatt-hour — generation. Technology already exists to let our electron-fueled gizmos know what the instantaneous cost of power is. So, if we were able to program our appliances and lighting to only run when that cost was low, consumers could help reduce the peaks and valleys in electrical generation (something utilities crave) — and cut our energy costs.

But the core of smart-grid technology — computer-controlled circuits, relays and sensors — would be vulnerable sitting ducks for EMPs, Bartlett charged. And he isn’t alone in feeling so.

Western society’s vulnerability to EMPs is very real, acknowledged Suedeen Kelly, a Federal Energy Regulatory Commission member who testified at today’s hearing.

“This is indeed a very serious concern that we must address in the context of the smart grid,” added George Arnold of the National Institute of Standards and Technology in Gaithersburg, Md. On the bright side, he said that at least some manufacturers are “sensitive to the issue” and have informed smart-grid developers of efforts being investigated to harden key circuitry.

However, Arnold cited a report on the nation’s EMP vulnerabilities that concluded it’s not practical to try and protect the entire electrical power system — or even all high-value components. So priorities will have to be set as to which assets are most critical,and then focus on shielding them.

But that’s at some indeterminate time in the future. What if a rain of EMPs arrived tomorrow, Bartlett asked?

Depending on the altitude of a detonation, a wide area could be impacted, noted Paul De Martini. This vice president for advanced technology at Southern California Edison, in Rosemead, Calif., also testified at today’s hearing.

Aspects of an EMP weapon might resemble a lightning strike — something the power grid should be able to handle, he said. But other features of an EMP assault would be more akin to events triggered by large solar flares and could damage large elements of the nation’s bulk-transmission system. This is especially true for some “very large, high-voltage transformers that are essentially custom-made,” De Martini said.

Although a spare unit might exist at one utility or another, De Martini noted that obtaining some units — like a new 500,000-volt transformer — requires a long lead time. How long? “It could be two to three years,” he said.

That might make the idea of an EMP attack tempting for some of America’s adversaries, said Bartlett. Because the electronic revolution has not reached North Korea, for example, he argued that it could weather an EMP with “little or no effect.”

But in the United States, a community zapped by EMP weaponry could expect nothing less than physical, economic and civic paralysis. An electronic Armageddon, if you will.

To maximize the real estate zapped, the detonation must take place at relatively high altitude so that the resulting line-of-sight stream of electrons would fan out across a huge swath. For instance, I noted in a story years ago, a small nuclear detonation from a satellite orbiting 250 miles above Omaha might literally shut down traffic coast-to-coast, fry bank computers everywhere and wipe out the North American power grid. Any and everything that relied on vehicles, electricity or computers would remain out of service until the fried circuits were replaced. All gazillion of them.

Only the Amish and others not reliant on late 20th — much less our 21st — century technology would escape unscathed. No wonder the military kept almost all data on EMPs classified until the mid 1960s. Even when I wrote a feature series on EMP weaponry, more than two decades ago, the Defense Department was still reluctant to talk about the nation’s vulnerability. Since then, public discussion of EMP has all but dried up.

But clearly it remains on Bartlett’s radar screen.

At today’s hearing, he recalled sitting in a hotel room in Vienna, Austria, with three members of the Russian Duma several years back. Bartlett said one of them boasted that if Moscow wanted to really injure America, with no fear of retaliation, it would simply authorize a sub to launch a ballistic missile. “’We’d detonate a nuclear weapon high above your country,’” the Russian official told him, “’and shut down your power grid — and your communications — for six months or so.’”

Bartlett recalled another of the Russians adding, ‘“If one weapon wouldn’t do it, we have some spares. Like about 10,000.”

Earlier this week, Bartlett reported, the Secretary of Defense told him that DOD was counting on “deterrence” to protect the United States from EMP terrorism. And Bartlett said he told him: ‘Mr. Secretary, that’s not going to work.’”

America’s leaders have to understand, Bartlett argues, that “The 'smarter' we make the grid, the more vulnerable we are. And unless you’re incorporating EMP protection, you’re simply making it worse rather than better, as far as security is concerned.” To stave off attacks, the congressman recommends that the United States look to technologically limit its vulnerability  — because “vulnerability invites attacks.”

If all of this sounds like a playbook for foreign terrorists, don’t worry; I’m hardly letting the cat out of the bag. A novel about an EMP attack on the United States is out, Bartlett noted this morning, and a feature film based on it is in the works.