— NEW YORK — The U.S. government has developed a suite of technologies that would enable it to determine the origin of a nuclear weapon used in an attack against the United States, according to a forthcoming book on America’s nuclear detectives.
In the event of such an attack, U.S. officials believe they could determine where the fissile material used in the nuclear weapon originated, as well as who carried out the assault, intelligence historian Jeffrey T. Richelson writes in “Defusing Armageddon.”
“Not only can intelligence help prevent a nuclear terrorist attack, but also in the event one occurs, it may be able to identify the entity responsible and those who contributed, particularly by providing a bomb or components,” Richelson claims in the first book-length treatment of these counter-nuclear efforts, including the Nuclear Emergency Search Team (NEST), America’s bomb hunters.
This is important, Richelson argues, because U.S. officials believe the most likely nuclear attack would involve an established nuclear power providing either a nuclear device or components to a terrorist group. Finding out which nuclear power provided these items to the terrorists would be key in crafting an appropriate U.S. response.
Earlier this month, a congressionally mandated task force reported that terrorists are likely to strike a major city with weapons of mass destruction by 2013. It added: "In our judgment, America's margin of safety is shrinking, not growing."
Richelson says U.S. officials want prospective terrorists — and the nuclear scientists who may be tempted to help them — to understand U.S. capabilities. Denying them the certainty that they can attack without consequences, U.S. officials feel, is critical to preventing an attack.
Ferreting out nuclear explosives
An attack on the United States would trigger a series of reactions among those responsible for determining the weapon’s origin. These efforts would be coordinated by the National Technical Nuclear Forensics Center, a little-known, three-year-old operation, which works closely with an Energy Department team tasked with ferreting out nuclear explosives before they go off and developing “nuclear forensics” to unearth the origin of a weapon.
U.S. officials would begin by determining the weapon’s precise location with the help of Defense Support Program satellites — infrared spy satellites that detect heat sources — and Global Positioning System satellites, all of which carry nuclear detection packages that could help pinpoint any detonation.
To gather nuclear debris — the key evidence in the detective story — a specially equipped Air Force WC-135 aircraft called “Constant Phoenix” would be deployed. The plane is a modified Boeing 707 that carries debris sampling and air-sampling equipment as well as devices to track radioactive clouds. One problem with this part of the plan, Richelson and others note, is that there is only one WC-135 left, down from a Cold War total of ten. Energy Department officials have called for development of Predator-like drones to fill the gap.
The debris would be analyzed and compared against a database of nuclear signatures, which the United States has been gathering as part of its intelligence efforts on foreign powers. With this information, the United States should be able to determine, at the very least, which country originally produced the highly enriched uranium or plutonium.
“The possibility of attribution stems from the fact that every nuclear device has distinct signatures. These include physical, chemical, elemental and isotopic properties that provide clues as to what material was in the weapon and its construction,” Richelson writes in his book, which is set for publication next month. “The shape, size, and texture of the material would determine the bomb’s physical signature. The bomb’s unique molecular components would determine the device’s chemical signatures.”
Figuring out the reactor
The United States also should be able to determine in which type of reactor the plutonium was produced, what the operating conditions were and its age, which would provide additional clues about its origins. The same would hold true for enriched uranium. There are enough signatures to suggest what kind of centrifuge — or electro-magnet — was used to enrich the uranium to bomb grade.
“By comparing the results of the initial analysis to a database of known reactor types or samples of HEU produced by different enrichment processes, forensic workers might determine the origin of the material or at least narrow the field of viable suspects, eventually pinning the blame on the culprit with the assistance of additional intelligence and data,” Richelson claims.
With all that in hand, Richelson says, the next step would be determining “bomb efficiency,” which in turn can help identify who designed the bomb.
“That information could reveal who built it. Current computer programs can assist in debris management by estimating the pre-detonation isotope mixture, which when combined with data on the mixture after the detonation might make it possible to infer the efficiency of the bomb’s design,” Richelson writes.
In turn, that could narrow down the bomb’s origin and who may have helped. But, for example, if the bomb resembled the Hiroshima bomb, called a gun-type design, it would indicate the “serious possibility that the device was made without assistance,” because those designs have been in open-source literature for decades.
Updating the database
Richelson admits that the success of nuclear detective efforts is dependent on the intelligence community’s ability to maintain a comprehensive and updated database. Otherwise, he notes, “confidence that the United States does not have samples a country’s nuclear DNA might make that country willing to provide terrorists with a bomb or nuclear material.”
These kinds of high-tech anti-nuclear efforts are likely to get the attention of the incoming Obama administration. Vice President-elect Joseph Biden has pushed for more funding and more basic research.
In 2007, Biden told the Wall Street Journal, “We need more nuclear forensics research, more scientists to analyze nuclear samples, and an assured ability -- using our own aircraft or those of cooperating states -- to quickly collect nuclear debris from the site of any attack, in this country or around the world.”
Moreover, Secretary of State-designate Hillary Rodham Clinton sponsored legislation to double the center’s budget last year.
Ironically, and perhaps tragically, says Richelson, the nuclear forensics technologies are more advanced than those associated with nuclear detection.
"Unfortunately, despite the skill and determination of NEST personnel, it may be easier to determine who was behind a terrorist nuclear attack than to prevent it."