OAK RIDGE, TENN. ? Construction of an above-ground storage complex for bomb-grade uranium will begin in August despite auditors’ concerns about the design, federal officials said.

An earlier proposal had called for partially burying the Y-12 National Security Complex, but U.S. Department of Energy spokesman Steven Wyatt said building the $250 million facility above ground will be “more flexible and cost-effective.”

That decision comes despite a March DOE inspector general’s report that questioned whether such a design would provide enhanced security. It also said the structure, which is expected to be completed in 2007, would cost more than a below-ground facility to build and operate.

Uranium stocks from around the Y-12 plant are to be consolidated in the new facility under heightened security,

Critics say an above-ground facility could harm security efforts.

“Instead of guarding one side of the building, you have to guard five,” Peter Stockton, a security analyst with the nonprofit watchdog group Project On Government Oversight, said.

Dennis Ruddy, president of BWXT and the plant’s general manager, disagrees, saying that burying the vaults wouldn’t automatically enhance security.

“Then you’ve got to have sensors in the building that would tell you if somebody is burrowing in under the ground,” Ruddy said. “If the facility is sitting out there and you’ve got a guard tower on every corner, you just have to look out the window to see if anybody’s monkeying around.”