By Calvin Biesecker
The new generation of radiation portal monitors show limited improvements over existing technology in primary screening applications when nuclear materials are lightly shielded and in some cases performed better than handheld radiation identification devices in secondary screening applications, the Government Accountability Office (GAO) said in a report issued yesterday.
The report says the Advanced Spectroscopic Portals (ASP), which are the new technology being developed to passively scan containers for the presence of radioactive materials, “were frequently able to detect certain nuclear materials when shielding was below threat guidance, and both systems had difficulty detecting such materials when shielding was somewhat greater than threat guidance.” The existing portal monitors are based on polyvinyl toluene (PVT) technology.
Customs and Border Protection (CBP) wants to eventually replace the PVT monitors because they give off numerous false alarms due to naturally occurring radioactive materials.
The Domestic Nuclear Detection Office (DNDO), the branch of the Department of Homeland Security responsible for the development and acquisition of radiation detection equipment for all of the department, didn’t test the ASP or PVT systems against higher levels of shielding because they are incapable of detecting threats at that point, GAO says. GAO’s report is entitled Combating Nuclear Smuggling: DHS Improved Testing of Advanced Radiation Detection Portal Monitors, but Preliminary Results Show Limits of the New Technology (GAO-09-655).
In secondary screening testing, the ASP systems outperformed handheld devices in identifying threats masked by naturally occurring radioactive material, the report says. “However, differences in the ability to identify certain shielded nuclear materials depended on the level of shielding, with increasing levels appearing to reduce any ASP advantages over the handheld identification devices–another indication of the fundamental limitation of passive radiation detection,” GAO says.
The performance of the ASP systems versus the PVT systems is critical given a pending certification by secretary of DHS that the new systems demonstrate a significant improvement in operational effectiveness before they can be purchased. DNDO said recently that it is hopeful for certification this October (Defense Daily, June 10). How big that step up in performance is crucial because the ASP systems are expensive.
GAO, citing a report it issued last September, estimates an ASP system will cost about $822,000 compared to $308,000 for a standard PVT system. It also says that CBP expects the operations and maintenance costs to be “significantly higher” for ASP systems because of their complexity.
Two companies, Raytheon [RTN] and Thermo Fisher Scientific [TMO], are developing competing ASP systems for DNDO. However, testing of late has not gone well.
One company’s system has completed integration testing but had field validation suspended by CBP due to “serious performance problems that may require software revisions,” GAO says. The problems led to an increase in the number of referrals to secondary screening compared to the PVT systems, CBP said. “Significant corrective actions” are required, according to CBP, before field validation resumes, GAO says.
The other company’s system had problems in integration testing and “may have to redo previous test phases to be considered for certification,” GAO says. This system is several months behind in testing, the report says.
GAO did say that DNDO’s testing program for the ASP systems has improved to the point of providing credible results.
DHS, in its response to GAO recommendations, disagreed with a call to further revise the ASP testing and certification schedule, saying it has a deliberate process in place to ensure that exit criteria are met.
Congressional officials yesterday asked DHS Secretary Janet Napolitano to thoroughly review ASP before certifying the program. The House Science Committee will hold a hearing tomorrow on the program.