Homeland Security chief Tom Ridge acknowledged Tuesday "an enormous amount of uncertainty'' about the new Department of Homeland Security, but asked workers to be patient while the department begins to take shape.

"I know there's a lot of anxiety,'' Ridge said. "I suspect there's an enormous amount of uncertainty. Hopefully, there is a little bit of excitement.''

Future department employees got a chance to lob questions at their potential boss — although many won't be answered until a new personnel system is worked out, he said.

One thing was certain: much will remain unchanged in the first year, Ridge said. The department's 170,000 employees will maintain their pay, benefits and other provisions under their current union contracts until a single personnel system is set up to replace those of the 22 agencies forming the department. Even after that, he said, the retirement system will not change.

The town hall meeting marked the beginning of the dialogue needed to forge the innerworkings of the department, said Ridge, who promised regular, "honest and candid'' communication with employees.

The Office of Homeland Security is in the process of becoming a Cabinet-level department. It will begin taking shape early next year, eventually comprising nearly two dozen government agencies ranging from the Coast Guard to the Secret Service.

President Bush chose Ridge to head the department, but Ridge must still be confirmed by the Senate.

Asked whether he found a physical home for the department yet, Ridge said his staff has been looking in Washington and neighboring states Maryland and Virginia, and hoped to find a place by March 1, when many of the agencies fold into the department. "As soon as we know, we'll let you know,'' he promised.

Serving a dose of pep with his answers, Ridge reassured workers of the task before them. "There is no conceivable way that this country can harden every target,'' he said. "... But around this whole enterprise is the notion of all of us working together to manage the risk.''

"It's not just about building a new department, it's about taking on this mission,'' he said.