Interior Secretary Ken Salazar said the government was awaiting results of a study on potential environmental harm to the region.
The federal government on Monday extended for six months a moratorium on new uranium mining claims in a million-acre buffer zone around the Grand Canyon as it awaits the conclusions of a study of potential environmental harm to the region.
But he said he was not yet ready to declare the area off limits to new mining claims for the next 20 years, as many local and state officials and environmental advocates have demanded. He said in a briefing at the Grand Canyon that a 20-year moratorium was his preferred solution but that more scientific study was needed.
The decision represents at least a partial victory for environmentalists, who have grown increasingly uneasy in recent months as the Obama administration has, in their view, seemed to retreat on several environmental and regulatory fronts. They were particularly unhappy with Mr. Salazar’s decision last month, under pressure from Republicans in Congress and energy interests, to reverse his own policy that would have set aside millions of federally owned acres as wilderness protected forever from energy exploration.
Mr. Salazar said that the relatively small number of existing mining claims around the canyon would be honored but that he was leaning strongly against allowing any new activity. He said he would make a final decision after an environmental impact statement was completed by the government this year.
“This alternative, if ultimately selected,” he said, “would ensure that all public lands adjacent to Grand Canyon National Park are protected from new hard-rock mining claims, all of which are in the watershed of the Grand Canyon.”
In 2009, Mr. Salazar placed a two-year moratorium on new uranium mining claims on a million acres of public lands surrounding the Grand Canyon, overturning a Bush administration policy that encouraged thousands of new claims when the price of uranium soared in 2006 and 2007. Many of the stakeholders are foreign interests, including Rosatom, Russia’s state atomic energy corporation, and South Korea’s state-owned utility.
That moratorium was to expire in July but will now be extended until the end of December.
The impact of Monday’s decision on global uranium supplies and prices was expected to be modest. The United States is not a major supplier of uranium ore, and demand has been declining since the Fukushima Daiichi nuclear plant disaster in Japan, as countries including Germany, Italy and Switzerland move to cancel planned nuclear plants and reduce their dependence on nuclear power.
According to the United States Geological Survey, northern Arizona contains enough uranium to meet the American nuclear industry’s needs for only about six years, and the Grand Canyon region holds just a fraction of that.
Representative Raúl M. Grijalva, Democrat of Arizona, has long been an opponent of uranium mining on public and tribal lands around the Grand Canyon. He said in an interview on Monday that Republicans might try to undo the decision to protect the land but that they would be, in his words, crawling uphill.
“It’s typical of their heavy-handed approach, and they’re going to lose on this one,” Mr. Grijalva said. “The canyon is a huge economic engine for tourism, a huge conservation issue and a huge issue of water supply for California and Las Vegas and the cities of Arizona.”
Representative Cynthia M. Lummis, Republican of Wyoming, denounced the decision, however, saying that the Obama administration’s environmental policies were costing jobs and forcing the nation to look overseas for supplies of oil and critical minerals.
“It’s a legacy of unemployment and high energy costs,” Ms. Lummis said in a statement. “We will not move this country forward until the war on Western jobs comes to an end.”