Doubts over radiation measurements
Japan's prime minister has sounded a resolute note, promising to win the battle against an overheating nuclear plant even as atomic safety officials raised questions about the accuracy of radiation measurements at the complex.
Naoto Kan was grave a week ago when he addressed this nation rattled by fears of radiation that has contaminated food, milk and tap water. But three weeks after a massive tsunami disabled the Fukushima power plant's cooling systems, Mr Kan vowed that Japan would create the safest system anywhere.
Japan will "do whatever it takes to win the battle" at Fukushima, he said in a televised news conference. And when the crisis ends: "We will establish a system that could respond to any situation based on an assumption that anything could happen."
While a massive earthquake and tsunami set off a series of events that disabled the plant, the accident has been exacerbated by several missteps along the way. Apparently spotting another mistake, the nuclear safety agency ordered Tokyo Electric Power (Tepco) to review its recent radiation figures, saying they seemed suspiciously high.
Tepco has repeatedly been forced to retract such figures, fuelling fears over health risks and eroding confidence in the company's ability to respond effectively to the crisis.
Among the measurements called into question was one that Tepco said showed ground water under one of the reactors contained iodine concentrations that were 10,000 times the government's standard for the plant, the safety agency's spokesman Hidehiko Nishiyama said. Sea water and air concentrations from this week also are under review.
"We have suspected their isotope analysis, and we will wait for the new results," Mr Nishiyama said, adding that the agency thinks the numbers may be too high.
Tepco has conceded that there appears to be an error in the computer programme used to analyse the data, but spokesman Junichi Matsumoto insisted that the glitch only affected readings for two radioactive isotopes, neither of which was iodine or other readings that have raised recent radiation concerns.
The Nuclear and Industrial Safety Agency has held out the possibility that a complete review of all radiation data collected since the tsunami might eventually be ordered.
In any case, it appears radiation is still streaming out of the plant, underscoring Tepco's inability to get it under control. The company has increasingly asked for international help, most recently ordering giant pumps from the US that are to arrive later this month to spray water on the reactors.