''I recognize that there have been problems in the past,'' Bodman said as he emerged wearing a hard hat from a five-mile tunnel drilled into the ancient volcanic ridge 90 miles northwest of Las Vegas. ''But we've been working very hard collectively to change that.''

Bodman said he hoped Congress would speed legislation the Energy Department proposed last week that would remove hurdles to licensing, building and operating the dump.

''The legislation will allow us to provide stability, provide clarity, as well as predictability to the Yucca Mountain project,'' he said, ''and will help lay a solid foundation for America's future energy security.''

The bill, sponsored in the Senate by Energy Committee Chairman Pete Domenici, R-N.M., faces a fight from Nevada's congressional delegation including Senate minority leader Harry Reid, D-Nev.

The measure would raise the amount of highly radioactive waste that could be entombed at the site from 77,000 tons to 132,000 tons, and it would tap a special nuclear waste fund, reducing its exposure to congressional budget battles. Some $9 billion has been spent so far on the $58 billion project.

Reid, traveling Thursday in Nevada, called the bill ''an admission of failure.''

''This bill will not pass the Senate, and I believe that Yucca Mountain will never open,'' Reid said.