Nuclear detection device is audited

The Department of Homeland Security has overstated the performance of costly new machines designed to detect radiological materials that could be used in bombs, according to an unreleased government report.

The department’s Domestic Nuclear Detection Office claims that new tests show the machines can more accurately detect and identify radioactive materials than existing equipment, according to a report by the Government Accountability Office, the investigative arm of Congress. But auditors said that cannot be backed up by statistical evidence.