It is one of the most likely ways that terrorists can cause mass casualties – a crude nuclear device smuggled into the country via a cargo container, truck, or boat. Yet, experts say, seven years after the 9/11 attacks, a gaping nuclear loophole remains at the nation's borders and seaports.
The original wide-sweeping and aggressive plan by the Department of Homeland Security (DHS) to install advanced radiation detection monitors at all the nation's seaports, borders, rail stations, and more has ballooned in cost even though its goals have been scaled back.
The program, according to the Government Accountability Office (GAO), was originally estimated at $1.2 billion two years ago and is now estimated to run over $3 billion, though the current plan eliminates placing monitors at rail stations and screening extra-wide trucks.
But cost is not the only issue; internal government investigations as well as outside experts have concluded that the new and 'advanced' radiation portal monitors that the Domestic Nuclear Detection Office (DNDO) proposes buying aren't worth their high price tag.
"The Advanced Spectroscopic Portal monitors are not cost-effective. Additional units should not be purchased," Tom Cochran, senior scientist at the Nuclear Program of the Natural Resources Defense Council, told Congress recently.
The new monitors, according to Cochran, do not reliably detect highly enriched uranium.
"If the threat has the wherewithal to develop an improvised nuclear explosive device out of HEU," Cochran said, "that same threat would have the wherewithal to defeat these systems almost 100 percent of the time".
Cochran also told Congress that he believes the priorities of the federal government's plan to protect the U.S. from a dirty bomb are misplaced and that the focus should be on eliminating the source of the material.
"I don't think we're going to solve this threat problem by pouring more money into advanced methods of detecting radiation coming across borders because the physics is simply against us with respect to the material that represents the greatest threat," said Cochran.
Last month's hearing was the latest installment of what has been a two year process in determining whether or not DNDO, under the umbrella of DHS, should upgrade the radiation detection monitors it uses to detect the presence of dangerous radiological material in vehicles and cargo containers.
"The DNDO needed to prove the increase in security we'd receive is worth the high price of the monitors," said Gene Aloise at the GAO. "They've never done that".
In 2006, the DNDO spent over $80 million on three new kinds of radiation monitors, all of which had lousy results in field tests, according to the GAO. The best performing of the new detectors was only able to correctly identify masked highly enriched uranium and depleted uranium 53 percent of the time, said the GAO. The other two performed even worse, with 45 percent and 17 percent success rates. Despite the low success rates in their own field tests, DNDO went ahead with an initial purchase saying they would continue to test the monitors.
Then in 2007 Congress demanded another round of tests and today testing continues on the devices, which have yet to be deployed at the nation's porous borders and ports. DNDO has purchased 75 of the monitors for around $360,000 each and critics say the office already has enough evidence before them to know they shouldn't but any more.
A spokesperson for DHS told ABCNews.com that it is the "prudent path" to "continue to undertake comprehensive testing and evaluation" of the portal detectors yet she declined to give a timeline for when the testing phase would end.
"The bottom line is that Secretary Chertoff will not certify the devices until all the testing has been completed," said DHS press secretary Laura Keehner.
Now, the latest criticism of the DNDO's testing comes this week in a new report by the GAO which concludes that the DNDO's most recent report on test results "could potentially be misleading" because the manner in which they are reported "makes them appear more conclusive and precise than they really are".
Keehner said that DHS has a "strong disagreement" with the GAO's statement that their test result presentation could be misleading.
At a recent Congressional hearing, Sen. Joe Leiberman (I-Conn.) expressed his concerns that the DNDO has not been forthcoming with the GAO in providing the documentation needed for them do their investigation.
"These are vitally important programs and the importance of GAO's work in helping Congress oversee them cannot be underestimated," said Leiberman.
Even with the proposed new technology, much of the responsibility to detect nuclear smugglers at the borders and ports rests with the inspectors themselves. In a 2006 government test, radiation detection alarms actually went off, but the undercover investigators used counterfeit documents, which said they were licensed to carry the material, to successfully get the material past border inspectors and into the country.