The Japanese government announced Friday that the damaged reactors at the crippled Fukushima No. 1 nuclear power plant have reached a state known as "cold shutdown," about nine months after a massive earthquake triggered a tsunami that caused its reactors to meltdown and sparked a nuclear crisis unseen for 25-years globally.

Japanese Prime Minister Yoshihiko Noda confirmed the declaration at a press conference later on Friday. Noda vowed to maintain the safety at the plant and speed up the decontamination work near the plant.

Noda said the government will spend more than 1 trillion yen to fund the move for the time being and 30,000 people will be mobilized next year to conduct decontamination work near the facility.

The condition is the target set for the second stage of a timetable by the plant's operator, Tokyo Electric Power Co. and the government to bring the crippled plant under control, as part of a broader roadmap to fully decommission the plant and dispose of the nuclear waste.

The next phase of the government's lengthy, 30-year decommissioning roadmap will see some of the 100,000 residents previously evacuated from the vicinity of the radiation-leaking plant allowed to return home, officials have said.

Initially only residents from locations that were exposed to low-level doses of radiation will be allowed to return home and a 20-km evacuation zone will be maintained around the majority of the plant and its facilities, pending ongoing studies, the plant's operator said.

Noda pledged on Friday that the government will do its best to enable the evacuees to return to their homes. He said the government will also conduct thorough health management in the future, which includes body check-ups.