WASHINGTON -- Nevada officials have requested more time to prepare challenges to the license application for a nuclear waste repository at Yucca Mountain.

A 30-day filing period for filing license contentions should be extended to 180 days, attorneys argued in a motion filed this week with the Nuclear Regulatory Commission.

The application expected to be filed by the Department of Energy in June will consist of more than 8,000 pages and will be backed up by about 100,000 pages of references, plus associated environmental studies.

The 30-day clock starts ticking for Nevada and other interested parties to file contentions after the NRC staff decides to docket the application. A docketing decision would be expected in the fall.

"Reviewing the (license application) will be a monumental task, unlike one that any potential NRC party has ever faced," attorneys said in the motion that was filed on Monday. "The 30-day period is grossly inadequate."

State officials have estimated they might prepare a record 250-500 challenges to the science research and engineering designs for the repository, as well as the Energy Department's program management. Some number of challenges likely will be consolidated or dismissed by NRC administrative judges before they can be aired, attorneys have acknowledged.

Nevada's five-member congressional delegation added its voice to the extension request in a letter sent on Wednesday to the NRC.

"In the interest of fairness and good public policy, the NRC should extend the time parties and potential parties have to review this material and submit thoughtful contentions to the commission," the lawmakers wrote.