Rockville, Maryland (CNN) -- The Nuclear Regulatory Commission was poised Monday to begin a 90-day review of Japan's nuclear crisis -- including a 30-day "quick look" -- so that any lessons learned could quickly be applied to the 104 commercial reactors in the United States.
At the commission's first meeting since the March 11 earthquake and tsunami, NRC's staffers assured the five-member body they had "a high degree of confidence" in existing safeguards at U.S. nuclear power plants. But the staff suggested both near-term and long-term reviews of problems that have plagued the Japanese reactors.
The 90-day study would use "all of the currently available information" out of Japan, and the staff would issue both 30-day and 60-day "quick look" reports to update the commission and allow for any necessary changes. Results will be made public, the NRC said, and longer term investigations would likely follow.
"Here in the United States we have an obligation to the American people to undertake a systematical and methodical review of the safety of our own nuclear facilities in light of the of the natural disaster and the resulting nuclear situation in Japan," said Gregory Jaczko, chairman of the NRC.
William Borchardt, the NRC's executive director for operations, said the NRC staff has continually asked itself whether it should be proposing regulatory changes in light of events in Japan. But existing information "if anything, it's given me a bit of confidence that all of these redundancies are paying off," he said.
The staff has concluded that "U.S. plants continue to operate safely," he said.
"We do not expect the releases of radioactive material that have occurred in Japan to have any effect on the health and safety of the U.S. population," he said. Naturally occurring radiation from the sun, rocks and other sources is "100,000 times" the amount measured in the U.S. originating from Fukushima, he said.
Borchardt also gave a status report on conditions at the Fukushima Daiichi plant in Japan.
"In my view, the fact that the off site power is close to being available for use of plant equipment is perhaps the first optimistic sign we've had that things could be turning around," he said
"We believe that the spent fuel pools on units 3 and 4... that the situation there is stabilizing, that the containment in all three units 1,2, and 3 appear to be functional, and that there is water being injected into the reactive vessels in units 1,2, and 3," Borchardt added. "I would say optimistically that things appear to be on the verge of stabilizing."
Borchardt said the source of gray smoke seen emanating from Unit 3 Monday was unknown, but said there apparently "has been no increase in temperature or in radioactivity."
Borchardt also elaborated on a U.S. government recommendation that U.S. citizens evacuate from a 50-mile radius around Fukushima. That decision, he said, was based not on radiation readings, "but on what at the time was possible" given likely core damage in three reactors and problems at spent fuel pools. The recommendation was prudent and conservative, he said.
Borchardt testified the U.S. principles which govern nuclear reactor safety -- a "defense in depth" strategy, robust containment systems, redundant safety systems, and emergency preparedness -- are being borne out by the Japanese experience. In particular, the Japan incident has shown the value of "station blackout" rules, which require nuclear plants to have backup systems in case electrical power is lost.
Borchardt said while the NRC has provided assistance to Japan, it has maintained its focus on its top responsibility, ensuring the safety of domestic nuclear power plants and materials.
The NRC has sent 11 of its personnel to Japan to assist in efforts there.
The commissioner of the NRC, William Ostendorff said, "I believe that our existing licensing and oversight activities assure us that our commercial nuclear plants in this country are safe. On the other hand, I know that we must and most certainly will conduct a thoughtful and rational examination of the NRC's regulatory framework with the information and lessons learned resulting from the instance in Japan."