Public support for increased nuclear power is waning in the wake of the crisis in Japan, according to two new polls out this week.

Instead, more Americans favor development of renewable energy resources, increased energy efficiency and more oil and gas drilling, the national surveys show.

A poll released yesterday by the Pew Research Center found that 52 percent of those surveyed oppose the increased use of nuclear power, up from 47 percent last October. And a separate poll out today from the Civil Society Institute found that 58 percent of Americans are "less supportive of expanding nuclear power in the United States" than they were a month ago.

The surveys come as the nuclear industry is bracing to take a hit as a result of earthquake- and tsunami-caused nuclear turmoil in Japan. Some Democrats in Congress have already begun questioning the safety of domestic nuclear reactors and calling for regulators to put the brakes on new permits and licenses. But Republicans insist nuclear power in the United States remains safe and must be a part of the nation's energy mix. And the Obama administration, so far, has remained supportive of the energy source.

Steve Kerekes, a spokesman for the Nuclear Energy Institute, a trade group, said the industry was not surprised by the decline in support.

"Our support declined after Three Mile Island, and over time, as we improved our operating performance and demonstrated that we're a reliable source of electricity to help drive our nation's economy, the numbers rebounded, and I daresay the difference, I think, we have this time that we didn't have last time would be the renewed commitment on industry's part to communicate our achievements to the American people," Kerekes said.

He said the trade group is coordinating with its members to help provide "credible information both on what's happening in Japan and within the industry" at home.

But opponents of nuclear power are already latching onto the polls' findings.

Sean Farren, a clean energy advocate at Environment America, said of the CSI poll, "This poll shows what we have long known; when Americans know the real risk of nuclear, they know it isn't worth it."

The surveys, both conducted last week, found that as support for nuclear power has diminished, public opinion has increased for other energy sources.

The CSI poll concluded that 76 percent of the 814 respondents are "more supportive than ... a month ago to using clean renewable energy resources -- such as wind and solar -- and increased energy efficiency as an alternative to more nuclear power in the United States." And 74 percent of respondents said they would support shifting federal loan guarantee funding from nuclear power to wind and solar.

The Pew poll noted a rise in public support for expanded offshore oil and gas drilling, which had waned last summer after the Deepwater Horizon blowout and oil spill. The survey found that 57 percent of the 1,004 respondents said they would favor more oil and gas drilling in domestic waters, up from 44 percent in a similar poll last June. Thirty-seven percent of respondents were opposed to increased drilling in the new poll, down from 52 percent last summer. The uptick in support could be due to escalating gasoline prices.