A port security drill showed that closing ports and borders is hard, reopening them is harder and the cost of shipping interruptions due to terrorism is potentially huge, The Associated Press reported.

About 70 people from the federal government, several port authorities and private companies participated in the exercise developed with former CIA Director James Woolsey and Dale Watson, former director of counterterrorism for the FBI.

Participants were given three fictional scenarios to which they were supposed to react.

In one, a radioactive ``dirty'' bomb is smuggled into the Port of Los Angeles. In another, a dirty bomb is unpacked in Minneapolis from a freight container that had been shipped through Canada. And in the third, the Georgia Ports Authority arrests three men - one on the FBI's terrorist watch list - in Savannah for trying to steal cargo.

Participants in the exercise - including representatives from the Transportation Security Administration, the Office of Homeland Security, the Customs Service and the port authorities of New York, New Jersey and Georgia - decided to close ports and border crossings. Foreign trade was halted and a search for bombs began.

The drill revealed a lack of crisis coordination and communication among government and the private sector, said Marc Gerencser, vice president of Booz Allen Hamilton, a management-consulting firm that sponsored the drill.

Companies that move freight strongly opposed the decision to close the ports, Gerencser said.

``The supply chain people said, 'You can't do this, it will kill us,''' he said.

The teams decided that after eight days, ports and borders could be reopened, but with the National Guard helping to inspect cargo. However, they also discovered it isn't easy to reopen a port.

``You have jurisdictions with competing interests,'' Gerencser said. ``The FBI wants to do crime-scene inspections and customs wants to bring in revenue. Nothing forces them to work together.''

Meanwhile, the consequences of the port closings were dramatic. Participants found it would take 92 days to work through the backlog of cargo, costing the U.S. economy $58 billion. Ships were stranded, importers and exporters lost money due to spoilage and lost sales, and manufacturers began to close plants.

President Bush signed a bill last month requiring the nation's 361 seaports to develop security plans. The law also creates a sea marshal program, marine anti-terrorism teams and new standards to make container seals tamper proof.

Congress left funding for port security to the Bush administration, which under the new law is required to submit a proposal within the next six months.