The 290-page report is expected to guide the 2012 General Assembly if it considers ending a 30-year ban on uranium mining. The report does not recommend whether it should be lifted, but makes clear the state must address a number of environmental and public safety issues before mining can occur.

The report points to many of the concerns raised by uranium mining opponents, who have argued the East Coast's wet, hurricane-prone climate is a risky environment for mining and milling, and for separating the radioactive ore from rock.

Full-scale uranium mining has never occurred on the East Coast, except as a byproduct of other mining.

Virginia Uranium Inc. has proposed working on a 119-million-pound deposit in Pittsylvania County, near the North Carolina border. The Coles Hill deposit, as it is called, is the largest known deposit in the U.S. and the seventh largest in the world.

The uranium would be processed into yellowcake used to power nuclear power reactors. The U.S. now imports more than 90 percent of its nuclear fuel.

If Virginia decided to end the ban, the NAS study said a muscular regulatory climate would have to be in place to ensure public and worker safety and to protect the environment.

"Significant potential environmental risks are associated with extreme natural events and failures in management practices," the report states. "Extreme natural events (e.g., hurricanes, earthquakes, intense rainfall events, drought) have the potential to lead to the release of contaminants if facilities are not designed and constructed to withstand such an event or fail to perform as designed."

Opponents said the report echoed the worries they've had for years.

"From our side, this is a huge validation of the core concerns we've been raising all along," said Cale Jaffe, a staff attorney with the Southern Environmental Law Center. Based on the report, he said, it would be "unfathomable" that the General Assembly would take up the ban in the upcoming session.

The report's authors presented it Monday to the uranium subcommittee of the Virginia Coal and Energy Commission. Members were divided on the impact of the report, some saying the issue warrants more study while others said the ban should be lifted so state regulators can answer questions raised by the report.

Sen. John C. Watkins, R-Powhatan, said he'd like to see Gov. Bob McDonnell have several state departments create a regulatory framework

McDonnell's office declined to directly respond to Watkins' suggestion, but issued a statement earlier that he would have state experts review the document and have their opinions by the beginning of the year.

The NAS report squarely placed the burden on the state to construct a regulatory process that protects the public and the environment.

Virginia Uranium, which has spent hundreds of thousands of dollars lobbying legislators, has said the deposit can be mined safely and will create an economic bonanza for Southside Virginia, which has struggled economically with the decline of tobacco and textiles.

The company said the study provides a "clear road map and path forward for operating the world's safest uranium mine in Virginia."

"I don't know that it raised any questions that already hadn't been there," said Patrick Wales, project manager for Virginia Uranium. "It talks about a lot of things that we've been talking about."

Two studies released in recent weeks have supported Virginia Uranium's rosy economic projections, but have also raised the prospect of potential environmental risks.

Opponents have argued that mining and milling would threaten water supplies if a catastrophic weather event occurred, scattering radioactive tailings into waters that are sources of public supplies as far away as Hampton Roads, nearly 200 miles away. Tailings are the waste product of milling the ore.

The $1.4 million NAS study, financed by Virginia Uranium, was conducted by the Committee on Uranium Mining in Virginia. Its members including experts in mining, the environment, public health and the nuclear industry.

Among its key findings:

— If the ban was lifted, uranium mining and processing are unlikely to begin for at least five to eight years. "This period of time should be used to build a robust regulatory and management culture focused on safety and citizen involvement," the study states.

— Extreme natural events, including earthquakes, should be considered when assessing the suitability the Southside site of the uranium mining operation. Virginia was rattled by a magnitude 5.8 earthquake in August.

— While Coles Hill is the only known economically viable deposit in Virginia, "significant uranium occurrences" can be found in the Blue Ridge and Piedmont areas. Critics have said lifting the ban would open the entire state to uranium mining.

— Mining, processing and reclamation all have the potential to affect surface and groundwater, soils and air. "These activities in Virginia will depend on site-specific conditions, the rigor of the monitoring program established to provide early warning of contaminant migration, and the efforts to mitigate and control potential impacts," the report states.

— Tailing disposal sites are potential sources of contamination for "thousands of years" and the long-term risks are poorly defined.

— If Virginia develops a regulatory framework for uranium mining and milling, it should exceed international industry standards.

— "The United States federal government has only limited recent experience regulating conventional uranium processing and reclamation of uranium mining and processing facilities," the NAS report states. That experience is even more limited in an East Coast climate.

Steve Szkotak can be reached on Twitter at http://twitter.com/sszkotakap.