A report from the Energy Department shows costs for the superconducting supercollider jumped nearly 50 percent and construction time extended another year.

In a report to lawmakers Tuesday, the department estimated the cost at $8.2 billion compared with the initial estimate of $5.3 billion and extended by one year its projected completion date, pushing it back to the fall 1999.The report said the cost increases were largely due to design changes recommended by scientists who said the improvements were needed to assure the project's success.

The facility, to be built in the Dallas-Fort Worth area of Texas, will be used by scientists to study subatomic particles in hopes of learning more about the fundamental properties of matter and energy.