YAKIMA, Wash. − The government plans to ask a judge to overturn a Washington state initiative that bars the Energy Department from sending radioactive waste from other states to the Hanford nuclear site until waste already there is cleaned up.

The measure is scheduled to take effect Dec. 2.

The Justice Department planned to seek a temporary restraining order Wednesday to keep the initiative from becoming law, The Associated Press learned from a government official familiar with the case who spoke on condition of anonymity.

The government also planned to challenge the constitutionality of the initiative on the grounds it violates federal laws governing nuclear waste and interstate commerce, the official said.

The 586-square-mile Hanford reservation was created in World War II as part of the top-secret Manhattan Project to build the atomic bomb. It remains the most contaminated site in the nation, with cleanup costs expected to total $50 billion to $60 billion.

At issue are the federal government's plans for disposing of waste from World War II and Cold War-era nuclear weapons production nationwide. The Energy Department chose Hanford to dispose of some mildly radioactive waste and mixed low-level waste, which is laced with chemicals.

The site also would serve as a packaging center for some highly radioactive waste -- plutonium-contaminated rags, tools and other discarded items -- before it is shipped elsewhere for long-term disposal.

In 2003, Washington state sued to block waste shipments from entering the state, fearing Hanford would become a radioactive waste dump. The Energy Department voluntarily suspended the shipments after the lawsuit was filed, but the case remains in federal court.

Source: Associated Press