The Washington Ecology Department formally denied Wednesday a federal request for more time to start removing boiling radioactive wastes from a Hanford storage tank.

Unofficially, the state gave the U.S. Department of Energy another year to start the work. But if removal is not under way by November 1998, the Energy Department risks fines of $10,000 per week dating back to this Halloween, the original deadline, the Ecology Department said.

The hot wastes pose a serious threat, officials at the Ecology Department said.

“High heat from within could damage the structure of this old tank, potentially causing tank failure and very serious threats to human health and the environment,” said Mike Wilson, state nuclear waste program manager in Olympia.

But the federal agency says safety concerns are behind the delays in removal.

Energy Department officials fear that trying to remove the wastes could cause a steam burst that would shoot radiation into the environment, said spokesman Guy Schein in the federal agency’s office in Richland.

Hanford manager John Wagoner was out of town, and Schein said he does not know how the Energy Department will respond to the state agency’s decision.

“We are trying to do things in a safe, effective manner that will get the waste out of there and not cause contamination to workers, the environment or the population,” Schein said.

But Wilson said the Energy Department has known about the safety concerns for years and has failed to address them.

The highly radioactive wastes, byproducts of four decades of plutonium production for nuclear weapons, are stored in 177 buried tanks containing up to 1 million gallons each.