WASHINGTON (AP) - The government shouldn't buy more of the new radiation detection machines it's been developing to look for smuggled nuclear materials at ports, a report from the National Research Council says.

The new machines are only marginally better at detecting hidden nuclear material than monitors already at U.S. ports, but would cost more than twice as much, says the report released Wednesday.

The Homeland Security Department, which oversees the development and deployment of the new machines, has already spent $235 million on them and could spend more than $1 billion.

The new report echoes concerns raised by Congress and the Government Accountability Office about the government's next generation radiation detectors.

Instead of purchasing more of the new machines, the government should deploy the devices it already has to ports and test them there, said the research council, part of the National Academy of Sciences.

Rep. Brad Miller, chairman of a House subcommittee that is scheduled to hear testimony about the machines Thursday, said it's time to slow down.

"We need to put the brakes on this program and thoroughly test and validate these new radiation monitors before we waste taxpayer money on a system that doesn't enhance our security," said Miller, D-N.C.

Because the threat of smuggled nuclear material and the technology to detect threats will continue to evolve, the Homeland Security Department should focus on deploying new machines incrementally instead of all at once, the report said.

The machines are intended to prevent terrorists or criminals from smuggling inside a cargo container a nuclear bomb or its explosive components.

The portal monitors now in use can detect the presence of radiation, but they cannot distinguish between threatening and nonthreatening material. Radioactive material found naturally in ceramics and kitty litter, for example, would be of no use in making a bomb.

The Department of Homeland Security says the new machines it is developing can distinguish between kitty litter and dangerous radioactive material and will produce fewer false alarms than the current ones.

The new machines are also better at detecting lightly shielded material. But the machines perform at about the same level when detecting radiological and nuclear materials hidden in a lead box or casing, the most likely way for a terrorist to attempt to sneak the materials into this country, the Government Accountability Office said in a report released Monday.

Homeland Security Department spokeswoman Sara Kuban said the department is doing a cost-benefit analysis on the current machines compared to the new ones.

---

On the Net:

tri-cityherald.com/galleries