Updated from 3/26/2011Updated with new challenges confronting Japan as it seeks to get a damaged nuclear power plant under control. By Mari Yamaguchi and Yuri Kageyama TOKYO -- Mounting problems, including badly miscalculated radiation figures and inadequate storage tanks for huge amounts of contaminated water, stymied emergency workers Sunday as they struggled to nudge Japan's stricken nuclear complex back from the edge of disaster. Workers are attempting to remove the radioactive water from the tsunami-ravaged nuclear compound and restart the regular cooling systems for the dangerously hot fuel. The day began with company officials reporting that radiation in leaking water in the Unit 2 reactor was 10 million times above normal, a spike that forced employees to flee the unit. The day ended with officials saying the huge figure had been miscalculated and offering apologies. "The number is not credible," said Tokyo Electric Power Co. spokesman Takashi Kurita. "We are very sorry." A few hours later, TEPCO Vice President Sakae Muto said a new test had found radiation levels 100,000 times above normal -- far better than the first results, though still very high. > > Bull or Bear? Vote in Our Poll But he ruled out having an independent monitor oversee the various checks despite the errors. Officials acknowledged there was radioactive water in all four of the Fukushima Dai-ichi complex's most troubled reactors, and that airborne radiation in Unit 2 measured 1,000 millisieverts per hour, four times the limit deemed safe by the government. Those high airborne readings -- if accurate -- would make it very difficult for emergency workers to get inside to pump out the water. Officials say they still don't know where the radioactive water is coming from, though government spokesman Yukio Edano earlier said some is "almost certainly" seeping from a damaged reactor core in one of the units. The discovery late last week of pools of radioactive water has been a major setback in the mission to get the crucial cooling systems operating more than two weeks after a massive earthquake and tsunami. The magnitude-9 quake off Japan's northeast coast on March 11 triggered a tsunami that barreled onshore and disabled the Fukushima plant, complicating a humanitarian disaster that is thought to have killed about 18,000 people.