Original article from Lexington Institute, June 6, 2014, by Daniel Gouré, Ph.D.
The greatest threat to the homeland is that a rogue power or terrorist group will slip a nuclear device onto a cargo ship bound for the United States. The detonation of such a device in a port such as New York, Long Beach, Norfolk, Charleston, Houston or Seattle-Tacoma would not only immediately cause hundreds of thousands of casualties and billions of dollars in damage but would probably shut down shipping into the United States for an indefinite period. The easiest way to accomplish this task would be putting the device inside a twenty-foot cargo container, millions of which come into this country aboard ship or across our northern and southern borders every year.
Back in 2007, Congress mandated that the Department of Homeland Security (DHS) have in place a system to screen all cargo coming into this country by December 31, 2011. Although DHS has achieved this goal for baggage and cargo aboard aircraft, it has not met the goal with respect to other modes of transportation, most notably shipping. The department has fought to delay the target date by which it would be required to meet the 100 percent screening requirement. Now, according to testimony before Congress by Kevin McAleenan, acting deputy commissioner for Customs and Border Protection, his agency acknowledged that once again it would miss the Congressionally-established deadline, this time set for July. More significant, the relatively new head of DHS, Jeh Johnson, announced that his agency now intends to flout the law entirely and limit its efforts to only screening cargoes inbound to the United States that it considers “high risk.” Why? Because, according to Johnson, the mandate is “highly improbable, hugely expensive [and] not the best use of taxpayer resources to meet this country’s port security and homeland security needs.”
Secretary Johnson’s decision is both wrong and unnecessary. It is wrong because while the arrival of a nuclear device into the United States may be a low probability event, the consequences would be so severe that defending against it must be a priority. Time and time again DHS and the intelligence community have been surprised by new and sometimes innovative attempts by terrorists to smuggle explosives aboard airplanes or conduct actions against U.S. targets. Mind you, this is the same department that requires you take off your shoes at airports because a lone terrorist tried to light a shoe bomb back in December, 2001. I would hate to see the sign “Jeh Johnson said this was Improbable” erected over the smoking ruins of a major U.S. port.
This decision is also unnecessary. There is a relatively cheap and highly effective way to screen virtually all containerized cargo for a nuclear device. Decision Sciences International Corporation, a private company, using its own funds, developed a relatively cheap and accurate cargo screening system called the Multi-Mode Passive Detection System (MMPDS). The MMPDS relies on naturally-occurring high energy neutron particles as its source and a simple detector array to measure the change in the path of the particles based on their interactions with the material inside the container. Dense materials such as uranium, plutonium and high explosives cause greater changes in the paths compared to less dense materials. The MMPDS can even detect shielded nuclear materials. Because the system is passive, meaning it doesn’t have to generate high energy particles such as x-rays, it is fast, relatively cheap, extremely accurate, safe and easy to operate.
DHS is familiar with this technology having paid for some of the testing and recently awarding the MMPDS its SAFETY (Support Anti-Terrorism by Fostering Effective Technologies) Act Developmental Testing and Evaluation Designation.
A scaled down version of the MMPDS could be deployed to screen smaller vehicles such as delivery trucks or postal vans. This version could even be placed at the warehouses used by all large package delivery services, allowing for screening of small boxes and even large envelopes. This would substantially reduce the risk from domestic terrorist bombers.
The MMPDS also addresses many of the concerns of shippers regarding screening systems. It is an open sensor array that can be erected across existing throughways such as at border crossings or cargo handling areas at ports. It takes so little time that screening would not appreciably slow down the movement of cargoes. If something suspicious is detected, the cargo can be diverted to a separate area for closer examination.
By the way, this technology has other applications as well. It can be “tuned” to use electrons instead of neutrons to detect less dense materials such as TNT or cocaine. A software change in the computer that interprets the movement of particles through the scanned material is all that is needed.