The Iowa Department of Transportation plans to install radiation detectors at five of the state’s weigh stations, an IDOT official told Land Line.

The machines are being installed as part of the state’s homeland security effort, Capt. Tom Sever of IDOT said. Intended as a deterrent, the machines can detect materials that can be used in “dirty bombs” – or more serious weapons.

“It’s just another technological tool we can use to scan more trucks for certain commodities,” he said.

Sever said final homes for the detectors had not yet been decided, but possible locations include:

• The Cedar Scale on I-80;
• The Dallas Scale on I-80;
• The Jasper Scale on I-80;
• The Worth Scale on I-35;
• The Clark Scale on I-35;
• The Fremont Scale on I-29; and
• A new scale being built on 218 in Lee County.

“We’re pretty sure that three will be on 80, at least,” Sever said. “And the others are tentative.”

He said the detectors will not delay trucks going through the scales; in fact, trucks should be able to move through at up to 20 mph. The only delays would occur if the machines detected something suspicious.

Officers at the scales will receive an alert from the detectors if the machines find any load containing radioactive material. The manufacturer told Iowa officials that only one out of every 1,000 trucks will generate a false reading, and the machines can be recalibrated if they are too sensitive.

“If something was detected, then we have handheld (detectors),” he said. “But we try to sort through everything before anything more serious takes place.”

Few trucks carry loads that would set off the detectors. Sever said radioactive materials make up less than 1 percent of all hazmat loads in the United States.

“They should not see any major changes,” he said. “Every now and again there might be a false reading, and if they have all their paperwork and documentation . . . that simplifies the process.”

The machines should not have any effect on drivers who pass through it. The detectors, unlike X-ray machines, do not project any type of radiation into the trucks. Rather, they detect whether anything is producing radiation inside the truck.

Sever said more of the machines could be added in the future, but “we’ll have to see how everything goes with these.”

“The unique thing about these are that they’re semi-portable, so we could actually, if things go well, pick up and move them from location to location,” he said.

Iowa joins a small list of states that have radiation detectors in use. The Des Moines Register reported recently that both California and Tennessee have similar machines in use. In Tennessee, one has been operating on the Interstate 40/75 corridor since 2002. And California has detectors operating at more than 15 of its truck inspection facilities, with more sites scheduled to have the machines by this fall.

The first detectors in Iowa could be installed as early as the end of the year.

--by Mark H. Reddig, associate editor

Mark Reddig can be reached at mark_reddig@landlinemag.com.