By Janet Raloff, for Science News' Science & the Public Blog
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.