Can Terrorists Build the Bomb?

STEP 1: ACQUIRE RAW MATERIALS

Buying or stealing an entire bomb would be extremely difficult, because most countries guard their nuclear weapons zealously and outfit them with mechanical locks or electronic codes to prevent tampering. Nuclear material, on the other hand, is at least in theory a lot easier to get. And, says Laura Holgate of the nonprofit Nuclear Threat Initiative in Washington, D.C., “Once you have material, everything is easier. Our mantra is, â€It’s the material, stupid.’”

Two metals can produce a mushroom cloud: uranium and plutonium. Uranium can be found in nature, though not in bomb-grade form. Uranium ore mined from the earth consists almost entirely of the relatively stable isotope U-238 and has only tiny amounts of the isotope
U-235, which is highly fissile—it splits easily, releasing large amounts of energy.


Before it can be used in a bomb, uranium must be “enriched,” a process that sifts out nonfissile U-238 to increase the proportion of fissile U-235. The more the uranium has been enriched, the more fissile it becomes and the less is required to make a bomb. Scientists generally consider uranium consisting of more than 20 percent U-235 to be “highly enriched” and suitable for a bomb, although uranium used in advanced nuclear-weapons programs and some nuclear reactors is enriched as much as 90 percent.


Enriching uranium is a vastly complicated and expensive process well beyond a terrorist group’s reach. It requires the use of expensive centrifuges whose production and export is closely monitored and which require sophisticated expertise to operate. Iraq tried in vain for years to enrich uranium, and Iran is approaching success only after decades of effort. “Iran has poured hundreds of millions—some would say billions—into their program, and as far as we know, they’re not there yet,” says Charles Ferguson, a science
and technology fellow at the Council on
Foreign Relations. Manufacturing plutonium is even more daunting. Plutonium is produced by irradiating uranium in
a nuclear reactor—hardly a practical option for most terrorists.


But while Iran and other nations are seeking full-fledged production capabilities, a terrorist group simply has to get its hands on enough material for a single bomb. All the next Mohammed Atta would need to make a bomb big enough to instantly obliterate everything within a third of a mile is about 100 pounds of uranium enriched to 90 percent: a lump about the size of a bowling ball, or a
bigger lump if the enrichment level is lower. It takes even less plutonium, which is far more fissile than uranium, to build an equally destructive bomb: about 35 pounds, a grapefruit-size hunk.


Given its greater potency, you might expect terrorists to covet plutonium for their bomb. Plutonium is so radioactive, though—far more so than uranium—that handling it can be quickly fatal. For the same reason, it makes radiation detectors go wild. Detonating plutonium requires a complex bomb design, with multiple explosive charges timed to exquisite precision. Finally, it tends to be stored at military installations and commercial power reactors, where security is generally very tight.


Uranium is an easier target. “Highly enriched uranium is more plentiful and more dispersed,” Cochran explains.
“It’s less well-guarded in the commercial
sector. It’s easier to handle in terms of toxicity.” Even prolonged exposure to uranium brings no short-term health effects. It can increase long-term cancer risks, but that wouldn’t deter a sui-
cide jihadist. Uranium’s relatively low
radioactivity also makes it harder to detect than plutonium. And crucially, Cochran says, “it’s easier to construct a crude [nuclear] device” from uranium.


That makes highly enriched uranium the ultimate attainment for a nuke-
building terrorist. Unfortunately, there are about two thousand tons of it stored worldwide. “Russia is the mother lode,” Holgate says. Huge military budget cuts in post-Soviet Russia allowed nuclear safeguards to lapse badly in the 1990s. The U.S. has been working with Russia to improve security at its nuclear facilities, but less than a quarter of Russia’s sites have been upgraded to meet standards set by investigators from the U.S. Government Accountability Office who visited several Russian nuclear facilities
in 2000 and 2001. At one site, they
discovered a gate to the main nuclear-
storage area wide open and unattended. At another, no guards responded when the visitors set off metal detectors. Not much nuclear material seems to have leaked from Russian military facilities, however, and although there have been numerous reports of attempted sales of stolen material, most have been frauds or “involve extremely small quantities of material,” Cochran says.


A more worrisome source of nuclear material is the civilian world, including research reactors such as the one at the Institute of Nuclear Physics in Uzbekistan. Some 130 reactors powered by highly enriched uranium operate in more than 40 countries, the product of an early Cold War-era program in which the U.S. and U.S.S.R. helped their allies obtain nuclear technology. Several more reactors are shuttered but may still
keep fuel onsite. Collectively, the world’s research reactors contain 22 tons of
highly enriched uranium, enough to build hundreds of nuclear bombs.


Research-reactor fuel tends to be stored under notoriously light security.
A later GAO report, published last year, found that “the fence surrounding the [unnamed foreign research reactor] facility was in poor condition, security guards at the front gate were unarmed, and there were no guards at the reactor building, which we entered without escort.” And security often amounts to little more than a couple of lightly armed guards—no match for a team of terrorists like the group that seized an elementary school in Beslan, Russia, last summer.


Unlike the bulky, extremely radioactive fuel rods used in commercial nuclear power plants, research-reactor fuel usually consists of small pellets that weigh only a few pounds each and aren’t too hot to handle. “[A] thief could easily put several of them at a time into a backpack,” wrote Matthew Bunn, a nuclear-proliferation expert who works with Graham Allison at Harvard, in a 2004 report.


Despite all this potential, virtually no nuclear material is known to have been smuggled out of research reactors. Which raises the question: If highly enriched uranium is so poorly protected, why
hasn’t more material gone missing? Proliferation experts cite two reasons for this happy surprise. In Russia, they say, the loyalty of underpaid military officials and nuclear scientists appears to be stronger than expected. Second, fears that organized crime syndicates would try to reap huge profits through nuclear smuggling have not yet been borne out, Holgate says. Why not? “Other activities of organized crime are way less hassle,” she suggests.


Fortunately, it’s only getting harder
for terrorists to steal nuclear material. During the 1990s, a joint U.S.-Russian program upgraded security at dozens of former Soviet nuclear installations. And in recent months, security has been improving at many civilian research reactors. With the Global Threat Reduction Initiative (GTRI), a program begun by the Energy Department last year with a budget of $450 million over 10 years, the U.S. hopes to secure vulnerable nuclear material around the globe. That means cataloguing nuclear material, increasing security at research reactors and, in some cases, removing uranium from places like Uzbekistan’s Institute of Nuclear Physics. Also under the GTRI, the U.S. is working to convert research reactors to run on uranium with an enrichment level below 20 percent, which is virtually useless for bomb-making.