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.
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 Daiichi 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.
Workers have been scrambling to remove the radioactive water from the four units and find a place to safely store it. Each unit may hold tens of thousands of gallons of radioactive water, said Minoru Ogoda of Japan's nuclear safety agency.
Meanwhile, plans to use regular power to restart the cooling system hit a roadblock when it turned out that cables had to be laid through turbine buildings flooded with the contaminated water.
Despite Sunday's troubles, officials continued to insist the situation had at least partially stabilized.
The protracted nuclear crisis has spurred concerns about the safety of food and water in Japan, which is a prime source of seafood for some countries.