YAKIMA, Wash. (AP) - Congress has decided not to reduce funding by an additional $100 million for a waste-treatment plant at the Hanford nuclear reservation, according to Rep. Doc Hastings, whose district includes the south-central Washington site.

The funding reduction, which had been proposed as part of a sweeping series of cuts to help pay for Hurricane Katrina relief, was widely criticized by officials in Washington state.

Hastings, R-Wash., said in a statement Monday the proposal deserved the bipartisan opposition it received.

"I'm pleased this is now ended. The administration should have never proposed this vit plant cut to Congress," Hastings said. "I hope our energies can now be dedicated to working with the department to set a path forward for the vit plant."

The Hanford site was created in the 1940s as part of the top-secret Manhattan Project to build the atomic bomb. Today, it is the nation's most contaminated nuclear site, and the vitrification plant is the cornerstone of cleanup work being managed by the Energy Department.

The plant, mired in delays and cost overruns for years, is being built to convert millions of gallons of highly radioactive waste stored in underground tanks into glasslike logs for permanent disposal in a nuclear waste repository. The department halted construction on large parts of the plant this year because of seismic concerns and skyrocketing costs.

The Bush administration cited those concerns in its $626 million budget request for the plant for 2006, down from $690 million in previous years. A House-Senate budget committee reduced that amount by another $100 million last month to $526 million.

In addition, the Bush administration had proposed tapping the 2005 budget for $100 million, money that was not spent but was intended to be banked for construction costs in later years. That proposal was part of a $2.3 billion package of cuts to help cover the costs of hurricane relief.

Washington state officials and the state's congressional delegation denounced the administration for labeling the funding as unnecessary. Gov. Christine Gregoire threatened to sue if the additional reductions were approved, calling them a clear violation of the federal government's cleanup obligations.

Gregoire, a Democrat, said in a telephone interview Monday that she was pleased with the news but still disappointed with the direction the project has taken. She also said she had not yet ruled out legal action, depending in part on future funding.

"We are by no means whole," she said. "I think I'm in a wait-and-see mode. Let's see what they do in the 2007 budget, and let's see if they get back to work on the construction of the waste-treatment plant."

Congress approved a series of hurricane-relief proposals Monday as part of a defense spending bill.

Hanford cleanup is governed under the Tri-Party Agreement, signed by the state, the U.S. Environmental Protection Agency and the Energy Department in 1989. Under that agreement, the plant must be operating by 2011, a deadline been pushed back three times from the original of 1999. The Energy Department has warned of the possibility of a fourth delay.