YAKIMA, WASH. ? The Bush administration said Wednesday that the government will spend an additional $450 million as part of a plan to speed the cleanup of the Hanford nuclear reservation.

Cleaning the nation’s most contaminated nuclear site will be accelerated by 35 to 45 years under an agreement reached Tuesday between the state, the Energy Department and federal regulators.

The agreement is the first reached under an Energy Department program aimed at streamlining cleanup of its sites around the country by working more closely with states and regulators. The target date for completing cleanup at Hanford, in south-central Washington, had been 2070.

The Bush administration agreed to restore $300 million it had cut from Hanford’s 2003 budget and provide an additional $150 million next year, bringing Hanford’s total budget to more than $2 billion in 2003.

The new agreement calls for speeding up retrieval of the more than 53 million gallons of highly radioactive waste stored in 177 underground tanks near the Columbia River. Over the years, the tanks have leaked more than 1 million gallons into the soil and groundwater.

Construction is expected to begin late this year on a huge plant to turn 10 percent of that waste into glass logs for long-term storage.

The new agreement also calls for faster cleanup of the Hanford corridor along the Columbia River, looking for alternative technology to dispose of less-radioactive waste, speeding up processing of scrap plutonium and speeding up cleanup of basins where lethal, corroding rods of spent nuclear fuel are stored.

Plutonium was made at the 560-square-mile Hanford site for more than 40 years for the nation’s nuclear arsenal, including the bomb that was dropped on Nagasaki during World War II.