A strategy and new deadlines to make environmental cleanup decisions for central Hanford have been agreed on by the Department of Energy and its regulators.
It's the final in a series of major changes to the legally binding Tri-Party Agreement that have been under negotiation during the past two years.
Earlier this month, new deadlines for retrieving radioactive waste from underground tanks and treating it at the vitrification plant were set. In September, new deadlines were set to address the cleanup of solid waste temporarily buried since 1970 until the nation had a geological repository available in New Mexico for transuranic waste, which typically is debris contaminated with plutonium.
The latest round of changes announced Friday set the stage for cleanup of central Hanford.
"We needed a strategy so as we complete cleanup of the river corridor by 2015, we could ramp up cleanup in the Central Plateau at the same pace," said Matt McCormick, manager of DOE's Hanford Richland Operations Office.
It's expected to be more challenging than cleanup along the Columbia River because contamination levels are greater, some of the buildings are larger and more complex and some of the contamination is so deep underground.
The 75 square miles of central Hanford has 900 unneeded structures, including five huge chemical processing plants, and 800 waste sites with buried waste or contaminated soil. It also includes the underground tanks holding 53 million gallons of radioactive waste, but that waste is being addressed separately in the Tri-Party Agreement.
The new deadlines are the first to include a focus specifically on one of Hanford's tough technical problems, deep soil contamination, after 450 billion gallons of contaminated liquids were discharged into the ground from World War II through the 1980s.
The soil contamination is too deep to just dig up at 250 to 300 feet below the surface and could contaminate ground water if it migrates deeper.
DOE will have until fall 2012 to submit a plan to investigate the deep soil contamination and until fall 2015 to develop a proposal for cleaning it up, said Craig Cameron, an Environmental Protection Agency scientist.
New technologies need to be developed and tested to immobilize it where it is, treat it while it remains underground or find a way to retrieve it without digging. DOE is investigating options that include drying out soil or using chemical methods to contain contamination.
Generally the new deadlines give DOE more time to prepare for the work, both because of technical challenges and because of a decision to focus cleanup and available dollars in recent years on cleaning up along the Columbia River rather than central Hanford.
The Tri-Party agencies have agreed to divide central Hanford work into three groupings for planning and cleanup: ground water, the inner area and the outer area. The inner area could be less than 10 square miles.
For the outer area and ground water, DOE will be required to have proposed plans complete by the end of 2012.
However, the inner area is more complicated and planning work has been divided into eight subprojects. They include the huge processing canyons for removing plutonium from irradiated fuel, waste burial grounds, liquid waste disposal areas and the deep contamination.
DOE, EPA and the state tentatively agreed to the changes in late March, but then accepted public comment before making a final decision this month.
w Annette Cary: 582-1533; acary@tricityherald. com; more Hanford news at hanfordnews.com.