The Senate insisted Thursday on opening up the Arctic National Wildlife Refuge for drilling after being blocked by environmentalists for decades, then voted overwhelmingly to prohibit exporting any of the oil pumped from the region. With a 51-48 vote, the Senate approved requiring the Interior Department to begin selling oil leases for the coastal plain of the Alaska refuge within two years, the Associated Press reported. Opening the refuge, which was set aside for protection 44 years ago, has been one of President Bush's top energy priorities. Bush, in Argentina for a two-day summit, hailed the vote. "Increasing our domestic energy supply will help lower gasoline prices and utility bills," he said in a statement. "We can and should produce more crude oil here at home in environmentally responsible ways. The most promising site for oil in America is a 2,000-acre site in the Arctic National Wildlife Refuge, and thanks to technology, we can reach this energy with little impact on the land or wildlife." Bush and other drilling advocates argue that the country needs the estimated 10.5 billion barrels of oil that are believed to lie beneath the refuges coastal tundra in northeastern Alaska and slow the growing dependence on oil imports. The United States now uses about 7.3 billion barrels of oil a year.