According to public broadcaster NHK, some 430,000 people are living in emergency shelters or with relatives. Another 24,000 people are stranded, it said.

 

One reason for the loss of power is the damage to several nuclear reactors in the area. At one plant, Fukushima Dai-ichi, three reactors have lost the ability to cool down. A building holding one of them exploded on Monday. Operators were dumping sea water into all three reactors in a final attempt to cool their superheated containers that faced possible meltdown. If that happens, they could release radioactive material in the air.

 

Though people living within a 12-mile radius were ordered to leave over the weekend, authorities told anyone remaining there or in nearby areas to stay inside their homes following the blast.

 

Military personnel on helicopters returning to ships with the U.S. 7th Fleet registered low-level of radioactive contamination Monday, but were cleared after a scrub-down. As a precaution, the ships shifted to a different area off the coast.

 

So far, Tokyo Electric Power, the nuclear plant's operator, is holding off on imposing the rolling blackouts it earlier said it would need but the utility urged people to limit electricity use. To help reduce the power load, many regional train lines were suspended or operating on a limited schedule.

 

The impact that lack of electricity, damaged roads and railways and ruined plants would have on the world's third-largest economy helped drag down the share markets on Monday, the first business day since the disasters. The benchmark Nikkei 225 stock average fell 6.2 percent while the broader Topix index lost 7.5 percent.

 

To lessen the damage, Japan's central bank injected $184 billion into money markets.

 

Beyond the stock exchanges, recovering from the disaster is likely to weigh on already debt-burdened Japan, which has barely managed weak growth between slowdowns for 20 years.

 

Initial estimates put repair costs in the tens of billions of dollars, costs that would likely add to a massive public debt that, at 200 percent of gross domestic product, is the biggest among industrialized nations.