Work to stabilize Japan's tsunami-hit nuclear power plant is on track and the government plans to declare it stable by the end of the year as planned, the prime minister said Friday.
Temperatures of the three melted reactor cores have fallen below the boiling point and radiation leaks have significantly subsided, Prime Minister Yoshihiko Noda said.
Those are the two key conditions to achieve what Japanese nuclear officials call "cold shutdown conditions," a milestone in the effort to stabilize and eventually close the Fukushima Dai-ichi plant altogether.
"We're about ready to draw a conclusion," Noda told a news conference Friday, marking the end of the current parliamentary session.
Some nuclear experts, however, question that claim because the nuclear fuel moved as it melted, so its condition and locations are little known.
The March 11 earthquake and tsunami that set off the radiation crisis at Fukushima Dai-ichi also heavily damaged the plant, and the damage and radiation concerns have limited how much information can be obtained about spent fuel rods and reactor cores.
The government and plant operator Tokyo Electric Power Co. are expected to make a monthly progress report around Dec. 16, and a formal announcement of cold shutdown is expected then.
Nuclear safety officials said the core temperatures and radiation leakage have met the requirements for some time now, and they are now making an overall safety evaluation to determine whether the plant can stably run the cooling system and properly launch crisis management steps in case of an unexpected development.
The crisis forced some 100,000 people to evacuate their homes, and part of the no-go zone near the plant may be uninhabitable for decades.
Noda said bringing the plant to the stable conditions is only a passing point on the path toward full closure of Fukushima Dai-ichi, which the government estimates will take 30 years.
Concerns about food safety stemming from radiation leaks in the area is also a pressing issue, Noda said, citing recent ban on rice grown in Fukushima and a trace of cesium detected in baby formula.
"We must address concerns about (food) safety and provide fuller explanations about it. We still need work in that area," he added.