TOKYO - Japanese Prime Minister Naoto Kan and Tokyo Electric Power Co. (TEPCO), operator of the troubled Fukushima No 1 nuclear power plant, said Tuesday that efforts to bring the crisis-hit plant under control were on schedule.

Despite a series of problems with a recently installed water circulation and decontamination system, the prime minister said Tuesday evening that the "first phase" of stable cooling had been achieved and the second stage of bringing the reactors to a safe status known as "cold shutdown" will continue.

Kan said that more progress than initially expected had been made to stabilize the plant, which was struck by a massive earthquake-triggered tsunami on March 11 that disabled the plant's vital cooling systems causing its reactors to meltdown and leak high volumes of radioactive materials into the air, land and sea.

The government stated Tuesday that it would stick to the initial time frame decided on April 17 of achieving a cold shutdown of the plant's three reactors by mid-January.

Japan's Nuclear and Industrial Safety Agency (NISA) describes this as a state in which the bottom of a pressure vessel in a reactor is held constant at 100 degrees Celsius or lower and radiation emissions are under control.

To this point the NISA also revealed Tuesday that the level of radioactivity currently leaking form the plant is just two- millionth of peak levels detected on March 15, at an annual radiation dosage of 1.7 millisieverts at the No. 1 nuclear plant's perimeters.

The government on Tuesday, however, only offered a rough three year timeframe for removing spent nuclear rods from reactor pools at the six reactor Fukushima complex.

Due to the perceived progress made in bringing the nuclear crisis under control, Industry Minister Banri Kaieda said that the government may allow some of the residents evacuated from the vicinity of the plant to return home earlier than expected. Up until now the government has imposed a mandatory 20-kilometer no- go zone around the plant, central to the world's worst nuclear disaster in 25 years.

In addition, the government announced the introduction of a 30- year program to monitor the health of the 2 million Fukushima Prefecture residents possibly exposed to harmful levels of radiation.

Around 45 percent of children in the prefecture checked in late March experienced thyroid exposure to radiation.

As Japan's nuclear saga continues to evolve, more than 600 beef cattle were found to have been fed with contaminated straw, some of which was believed to be 520 times over the legal limit, and sent for processing between March 28 and July 6.

Subsequently, Japan has banned all beef cattle shipments from Fukushima Prefecture, after meat from the prefecture showed high levels of radioactive cesium. Some of the meat has already been sold and consumed, officials said Tuesday.