WASHINGTON (Reuters) – U.S. public support for expanding nuclear power appears to be slipping after Japan's nuclear crisis while New York's governor said on Tuesday an aging plant near New York City will be the top priority in a federal review of earthquake risk to such facilities.

President Barack Obama last year announced loan guarantees to build the first U.S. nuclear power plant in nearly three decades. But the nuclear disaster triggered by Japan's 9.0 magnitude earthquake may be making Americans less inclined to embrace more nuclear energy due to safety fears.

In a poll released on Monday by the Pew Research Center for the People & the Press, 52 percent of 1,004 U.S. adults surveyed from March 17-20 said they oppose the expansion of nuclear power now, up from 47 percent last October.

A poll of 814 U.S. adults released on Tuesday by the Civil Society Institute, which has been critical of nuclear energy, found that less than half of those questioned -- 46 percent -- said they support more nuclear power reactors in the United States and 44 percent oppose new reactors.

Fifty-eight percent of those questioned said they are less supportive of expanding nuclear power in the United States than they were a month ago. The poll was conducted March 15-16.

"The Fukushima nuclear reactor disaster in Japan is causing a renewed and intensifying skepticism about the future of nuclear power," said Pam Solo, president of the Civil Society Institute, based in Newton, Massachusetts.

Many Americans have harbored safety concerns about nuclear power since the 1979 disaster at the Three Mile Island plant in Pennsylvania.

New York Governor Andrew Cuomo said the Nuclear Regulatory Commission (NRC) has pledged to make the Indian Point nuclear power plant north of New York City their top priority in a review of seismic risk at U.S. nuclear plants.

PLANT'S SAFETY DEFENDED

Indian Point owner Entergy Corp purchased a full-page advertisement in the New York Times on Tuesday touting comments by U.S. Energy Secretary Steve Chu saying that the reactor is safe and an NRC report saying all U.S. nuclear plants remain safe.

An NRC report last September found Indian Point, situated near two geological fault lines, was at the greatest risk from seismic activity among the 27 nuclear plants under review. The plant provides up to 30 percent of New York City's power.

Entergy also said it is considering a plan to store mobile emergency generators off-site that could be relocated to Indian Point after any emergency. Reactors at the crippled Japanese plant overheated when the tsunami knocked out backup generators to power the cooling system. The quake had cut off main power.

A report from the International Atomic Energy Agency questioned whether utilities licensed to run older U.S. nuclear reactors are doing enough to upgrade plant safety.

The report, issued by the U.N. nuclear watchdog two days before the earthquake and tsunami that crippled the Fukushima power plant in Japan, sounds an alarm about the safety at some older U.S. nuclear plants.

The IAEA assessed how America's nuclear plants are regulated at the request of the NRC.

Obama last week ordered a comprehensive review of the safety of U.S. nuclear power facilities, maintaining his support for nuclear energy while seeking to apply lessons from the situation in Japan.

Some lawmakers and anti-nuclear activists have called for safety measures in quake-prone California, where the Pacific Gas & Electric's Diablo Canyon plant and Edison International's San Onofre plant sit near faults.

"New information about the severe seismic risk ... make clear that these two plants require immediate attention in light of the catastrophic events in Japan," said Barbara Boxer, who along with fellow California Democratic Senator Dianne Feinstein has asked the NRC to conduct a review of the safety and emergency preparedness of the plants.

(Editing by Will Dunham)

ALBANY, New York (Reuters) – U.S. regulators have promised to make the Indian Point nuclear power plant near New York City their top priority in a review of seismic risk at U.S. nuclear plants, New York Governor Andrew Cuomo said on Tuesday.

The plant 25 miles of New York City, already a source of safety concern among state officials, has faced renewed scrutiny since the March 11 earthquake and tsunami that crippled Japan's Fukushima Daiichi nuclear power complex.

Cuomo, a Democrat who has worked to prevent the federal relicensing of the Indian Point facility, said the U.S. Nuclear Regulatory Commission has pledged to make the plant its "top priority" as it reviews earthquake risk at 27 nuclear facilities throughout the country.

"It is essential that the NRC move quickly to answer the significant and longstanding safety questions surrounding Indian Point," Cuomo said after New York state officials met with regulators at the NRC's Maryland headquarters.

An NRC report in September found Indian Point was at the greatest risk from seismic activity among the nuclear plants under review. Indian Point sits near two geological fault lines. The plant provides up to 30 percent of New York City's power.

The NRC will be investigating 27 plants' ability to handle earthquakes.

"It is important to note that while the study indicated the seismic risk has increased for some plants, it is not by a margin that would give us cause for any immediate concern," Eliot Brenner, a spokesman for the NRC said in a statement.

Indian Point owner Entergy Corp purchased a full-page advertisement in The New York Times on Tuesday touting comments by U.S. Energy Secretary Steve Chu saying that the reactor is safe and an NRC report saying all U.S. nuclear plants remain safe.

It was built to withstand an earthquake 100 times the magnitude of any quake measured in the area, Entergy said in the advertisement. The company has pledged to conduct its own review of seismic risk and safety procedures.

Entergy also said it is considering a plan to store mobile emergency generators off-site that could be relocated to Indian Point after any emergency. Reactors at the crippled Japanese plant overheated when the tsunami knocked out backup generators to power the cooling system. The quake had cut off main power.

The NRC has agreed to share data related to seismic risk with the state and will include the governor's staff in on-site reviews of the plant, said Lieutenant Governor Robert Duffy.

"This is an emotional topic, and we want to make sure we have all the facts before we make a decision," said Cuomo, who added that he does not know when the review would take place but that it would be "expeditious."

WASHINGTON (Reuters) – The United States will block imports of milk and fresh produce from areas of Japan near a crippled nuclear power plant, the Food and Drug Administration said on Tuesday.

All milk and milk products and fresh fruits and vegetables from four Japanese prefectures -- Fukushima, Ibaraki, Tochigi and Gunma -- will be stopped from entering the United States, the FDA said in a statement.

The agency was responding to fears that contaminated food from Japan could make it to U.S. stores.

Above-safety radiation levels have been discovered in 11 types of vegetables from the Fukushima area in northeast Japan where a six-reactor nuclear plant was battered by a March 11 earthquake and tsunami, the Japanese government said.

Radiation also has also been found in milk, tap water and the nearby Pacific sea, although Japan and experts insist levels are still far from dangerous to humans.

The agency said previously that exports from Japan were limited due to the infrastructure damage from the disaster.

Japanese officials also have ordered a stop to the sale of raw milk, spinach and kakina from Fukushima prefecture, and of spinach and kakina from Ibaraki, Tochigi and Gunma prefectures.

Foods from Japan make up less than 4 percent of all foods imported into the United States, the FDA said.

(Editing by Peter Cooney)