Nevertheless, officials remained hopeful they can stick to their freshly minted "roadmap" for cleaning up the radiation leak and stabilizing the Fukushima Dai-ichi plant by year's end so they can begin returning tens of thousands of evacuees to their homes.
"Even I had expected high radioactivity in those areas. I'm sure (plant operator Tokyo Electric Power Co.) and other experts have factored in those figures when they compiled the roadmap," Chief Cabinet Secretary Yukio Edano said.
Officials said Monday that radiation had spiked in a water tank in Unit 2 and contaminated water was discovered in other areas of the plant. They also described in detail for the first time the damage to fuel in three troubled reactors, saying pellets had melted.
That damage — sometimes referred to as a partial meltdown — had already been widely assumed, but the confirmation, along with the continued release of radiation from other areas, serves to underscore how difficult and how long the cleanup process will be. In fact, government officials themselves have acknowledged that there are still many setbacks that could crop up to slow down their timeline.
Angry at the slow response to the nuclear crisis and to the catastrophic earthquake and tsunami that caused it, lawmakers tore into Prime Minister Naoto Kan.
"You should be bowing your head in apology. You clearly have no leadership at all," Masashi Waki, a lawmaker from the opposition Liberal Democratic Party, shouted at Kan.
"I am sincerely apologizing for what has happened," Kan said, stressing the government was doing all it could to handle the unprecedented disasters.
TEPCO's president, Masataka Shimizu, appeared ill at ease as lawmakers heckled and taunted him.
Workers have not been able to enter the reactor buildings at the stricken plant since the first days after the cooling systems were wrecked by the March 11 earthquake and tsunami that left more than 27,000 people dead or missing. Hydrogen explosions in both buildings in the first few days destroyed their roofs and scattered radioactive debris.
Click image to see photos of quake, tsunami damage