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.