OLYMPIA — A new leak has been discovered in a nuclear waste storage tank at Hanford, federal authorities told state officials Friday. Gov. Jay Inslee, in a hastily called news conference, said he was advised of the leak Friday morning by the U.S. Energy Department and vowed to take legal action if necessary to force the federal government to clean it up and continue with other work at the Central Washington nuclear reservation, where millions of gallons of Cold War nuclear waste are buried in decaying tanks. “We were told this problem was dealt with years ago,” Inslee said. “Washington state has a zero tolerance policy on nuclear waste leaks.” Although the Hanford Nuclear Reservation has an estimated 1 million gallons of nuclear waste materials that have leaked into the soil around the tanks, this newly discovered leak comes in a tank that was thought to be stable. The single-walled tank, designated as T-111, has about 447,000 gallons of highly toxic transuranic waste, mostly sludge. It is leaking at a rate of about 150 to 300 gallons a year, a rate that is hard to detect. Most of the liquid was pumped out of the tank in the 1990s, and it was considered “stable” in 1995, Keith Phillips, the governor’s energy policy adviser, said. But water flowing through the porous soil is apparently entering the tank and some waste flowing out. No one knows how long the leak has been occurring. Hanford has a total of 177 tanks, some single-walled, others double-walled, which hold the waste generated by years of nuclear weapons production. Hanford was part of the Manhattan Project and helped develop the bomb dropped on Nagasaki, Japan, to help end World War II, and for years after the war helped process the uranium and plutonium used for the nation’s nuclear weapons. The leak does not create an immediate risk to public health, Inslee and other state officials said. It is underground, and could take years or even decades to reach the ground water, and an unpredictable amount of time to flow through the groundwater to the Columbia River. Hanford has a pumping station near the river that can remove most — although not all — contaminants from ground water before it flows into the river, Phillips said. Inslee said he was more concerned about the federal government’s response, even though U.S. Energy Secretary Steven Chu has been been an ally for the state in pushing for cleanup at Hanford. Across-the-board budget cuts that would be required by sequestration scheduled to begin in March could hamper any cleanup of the spill, he said. If Congress doesn’t find an alternative way to cut spending or raise taxes, workers at Hanford would likely be furloughed to satisfy the cuts from the sequester, he said. If that happens, Washington will consider legal options to force the government to keep up the pace of cleanup and address the leaking tank. “We are not going to be trapped into a dead end of arguing about priorities,” Inslee said. “I’m not coming here to say we’re going to start a lawsuit today. We are not unaware of our legal rights and we know where the federal courts are.” State Sen. Sharon Brown, a Republican whose district includes Hanford, said the leak highlights the need for more resources at the nuclear reservation. Gerry Pollet, executive director of Heart of Northwest, a citizen watchdog group, said the leak shows the state and federal government need a new plan to build new tanks quickly, empty the leaking structures, clean up the nuclear residue and remove the waste under the old tanks before more contamination reaches the Columbia River.