Federal nuclear regulators issued a hopeful report today on Japan's nuclear crisis and outlined plans for a two-tiered review of the safety of 104 U.S. reactors.

Containment Units 1, 2 and 3 at the crippled Fukushima Daiichi nuclear plant, which was rocked by a massive earthquake and tsunami on March 11, appear to be stabilizing, as are spent fuel pools at the complex, said Bill Borchardt, the U.S. Nuclear Regulatory Commission's executive director of operations.

The earthquake affected 10 reactors, and the ensuing tsunami caused a loss of emergency power to six units at the Fukushima Daiichi plant. In the wake of explosions and fires at the power plant, NRC is now struggling to ascertain if Units 1, 2 and 3 have experienced core damage, Borchardt said.

"Today, all three units appear to be in a stable condition with seawater injection being used to keep the reactors cool," Borchardt told commissioners today. "Containment integrity for all three units is also currently maintained."

Although gray smoke was seen rising from the nuclear complex this morning, Borchardt said there were no indications of increased temperature or radioactivity at the plant (see related story).

Tokyo Electric Power Co. has extended power to a site near the crippled plant, and Japanese officials are in the process of laying temporary cables to pumps and valves in Units 1 and 2 and will do the same for Units 3 and 4 during the next couple of days, he said.

"The fact that off-site power is close to being available for use at plant equipment is perhaps the first optimistic sign that things could be turning around," Borchardt said.

NRC has sent at least 11 experts to Japan to gather information and consult with Japanese officials.

U.S. reactor review

NRC could vote as early as today on plans to conduct a 90-day review of information coming out of Japan and how those findings relate to oversight of the fleet of U.S. reactors.

The short-term review will provide a snapshot of U.S. reactor safety and could evaluate how nuclear plants would deal with emergencies.

NRC reports will be made after 30 and 60 days and have limited stakeholder involvement, Borchardt said.

The plan will also address the implementation of a separate long-term review of technical issues and potential changes to NRC's oversight program and rulemakings, Borchardt said.

The commission has not stated a start date of that lengthier review because it would be launched after more conclusive information is obtained on the Japan disaster. That study, he said, will include "substantial stakeholder involvement."

Simultaneously, NRC has launched a plant-by-plant review that President Obama called for last week (E&ENews PM, March 17).

The commission is reviewing its 35-year regulatory framework in light of the Japan crisis.

Borchardt said the agency is confident in the safety of the U.S. fleet. NRC has fine-tuned its regulations in response to past emergencies, including the partial meltdown at Pennsylvania's Three Mile Island power plant and the terrorist attacks of Sept. 11, 2001.

The agency has issued a notice to the industry that the commission will be following up to ensure that emergency responses at U.S. reactors "haven't fallen into disuse because they haven't been used," Borchardt said.