RICHLAND, Wash. — The Energy Department wants to reduce the active management area at the Hanford nuclear reservation to as little as 10 square miles, less than 2 percent of Hanford's original 586 square miles.

The cleanup of 210 square miles along the Columbia River is going well and is scheduled for completion by 2015, the department's assistant manager for central Hanford, Matthew S. McCormick, told the Tri-City Herald.

Also planned is a less extensive cleanup of non-radioactive debris and some buildings in the 300-square-mile Hanford Reach National Monument, and areas that once a security perimeter around the nuclear works where fuel was made for atomic bombs starting in World War II.

An Environmental Protection Agency scientist, Dennis Faulk, says it's hard to believe that within a few years, the restricted area may be down to just the central Hanford plateau.

"It's hard to believe that Hanford could be known only as the central plateau in a few years," said Dennis Faulk, an environmental scientist with the Environmental Protection Agency. "This is really what we've been working toward and it's really starting to crystallize."

Cooperation with regulators has been vital, McCormick said.

Under the Tri-Party Agreement, the Energy Department, EPA and state Department of Ecology signed an agreement in principle this winter to discuss a cleanup strategy for the 75-square-mile central plateau, much the same process as was used for the area along the river.

Energy officials are proposing to divide the area into an outer zone with less contamination which would be restored for unrestricted surface use, and an inner zone of 20 square miles or less limited to industrial purposes with part of the area set aside for long-term waste management, including lined disposal areas for radioactive waste.

Also in the inner zone would be a disposal area for decommissioned nuclear submarine reactor vessels, underground waste tanks that are being emptied, fuel reprocessing buildings and US Ecology, a commercial low-level radioactive disposal facility.

Reprocessing buildings, or canyons, may be partially demolished for permanent disposal of waste underground.

Central Hanford was used for chemical processing of fuel irradiated at nearby reactors to separate plutonium, leaving contaminated soil too deep beneath the surface to dig up.

In the outer zone, where contamination is more shallow, the Energy Department is proposing to remove soil as needed for treatment and disposal at the Hanford landfill for low-level radioactive waste.

The outer zone includes about 180 waste sites such as ponds used for cooling water from heat exchangers in industrial facilities that may have had some chemical contamination, as well as areas where animals have spread radioactive contamination near the surface and areas where water that was used to shield irradiated fuel spilled as it was moved from reactors.

A key goal is to reduce the 80 square miles of contaminated ground water plumes at Hanford to a few small areas, mostly in the central plateau where it may not be technically possible to reach drinking water standards, McCormick said.

Ground water entering the Columbia River would be maintained at higher than drinking water standards, reaching the levels needed to protect fish and other aquatic life from chemicals such as chromium.

"It's a really good step forward," Faulk said.