TOKYO - (AP) - Two weeks after a tsunami triggered a crisis at anuclear plant, Japan's government said Friday there is a possiblebreach at a reactor - meaning radioactive contamination at thecomplex is more serious than once thought - but there could beother explanations for highly radioactive water detected at thesite. Japanese leaders defended their decision not to evacuate peoplefrom a wider area around the plant, insisting they are safe if theystay indoors. But officials also said residents may want tovoluntarily move to areas with better facilities, since supplies inthe tsunami-devastated region are running short. The escalation in the nuclear plant crisis came as the deathtoll from the quake and tsunami passed 10,000 on Friday. Across thebattered northeast coast, hundreds of thousands of people whosehomes were destroyed still have no power, no hot meals and, in manycases, no showers for 14 days. The uncertain nuclear situation again halted work at theFukushima Dai-ichi complex, where authorities have been scramblingto stop the overheated facility from leaking dangerous radiation.Low levels of radiation have been seeping out since the March 11quake and tsunami knocked out the plant's cooling system, but abreach could mean a much larger release of contaminants. The mostlikely consequence would be contamination of the groundwater. "The situation today at the Fukushima Dai-ichi power plant isstill very grave and serious. We must remain vigilant," a somberPrime Minister Naoto Kan said. "We are not in a position where wecan be optimistic. We must treat every development with the utmostcare." The possible breach in the plant's Unit 3 might be a crack or ahole in the stainless steel chamber of the reactor core or in thespent fuel pool that's lined with several feet of reinforcedconcrete. The temperature and pressure inside the core, which holdsthe fuel rods, remained stable and was far lower than what wouldfurther melt the core. Suspicions of a possible breach were raised when two workerssuffered skin burns after wading into water 10,000 times moreradioactive than levels normally found in water in or around areactor, the Nuclear and Industrial Safety Agency said. Water with equally high radiation levels was found in the Unit 1reactor building, Tokyo Electric Power Co. officials said. Waterwas also discovered in Units 2 and 4, and the company said itsuspects that, too, is radioactive. Officials acknowledged thewater would delay work inside the plant. Plant officials and government regulators say they don't knowthe source of the radioactive water discovered at Units 1 and 3. Itcould have come from a leaking reactor core, associated pipes, or aspent fuel pool. Or it may be the result of overfilling the poolswith emergency cooling water. Friday marked two weeks to the day since the magnitude-9.0 quaketriggered a tsunami that flattened cities along the northeasterncoast. With the cleanup and recovery operations continuing and morethan 17,400 listed as missing, the final number of dead wasexpected to surpass 18,000.

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Concern in Tokyo over radiation in tap waterPower lines up in progress at Japan nuclear plantJapanese helicopters drop seawater on nuclear reactor