Washington, D.C. ? It will cost $26.9 billion to build and operate the Yucca Mountain nuclear waste dump through 2023, the Energy Department said Friday in a new cost calculation.

The department did not release a new figure for the total life-cycle cost of the Nevada project, estimated several years ago at $58 billion. The department plans to recalculate that figure in May and it almost certainly will rise, said Edward F. “Ward” Sproat, director of the Energy Department’s Office of Civilian Radioactive Waste Management.

The $26.9 billion figure, about in line with recent estimates, assumes that the department meets its goal of opening the repository in March 2017, Sproat said during a conference call.

That 2017 opening date is a best-case scenario and Sproat cautioned it will slip if the department does not get the money it needs each year for the dump.