More tests need to be carried out before the Japanese nuclear plant damaged in last month's earthquake is reopened, UN inspectors say.
Radioactive leaks from the plant have alarmed the public
The team from the International Atomic Energy Agency have just concluded a four-day inspection of the Kashiwazaki-Kariwa plant.
Head of the team Philippe Jamet said it could take months or longer for the plant to be operational again.
The plant suffered some 50 malfunctions after the 6.8 magnitude quake.
There was particular alarm after it emerged that leakages of radioactive material had been much bigger than initially estimated.
The plant's operators, The Tokyo Electric Power Company, says there is no danger to the public.
Mr Jamet told reporters that further tests were needed to assess the full extent of the damage to the Kashiwazaki-Kariwa power station.
"This is one of the tasks in the following months, year, I don't know, to be carried out if this plant is to be restarted," he said, following the six-member IAEA team's inspection of the site.
Clouds of smoke poured from the nuclear power plant on Monday
The IAEA visit was requested by the regional government in Niigata. Tokyo initially said no international inspection was necessary.
Niigata officials said bringing in outside experts would help to damp down rumours that the radiation leaks had been more serious than admitted.
The plant - reported to be the world's largest - supplies around 10% of Tokyo Electric Power's output.
The firm has said contaminated water needs to be cleaned up and dozens of other problems need to be fixed before the plant can be reopened.
Ten people were killed and hundreds were injured when the earthquake struck in mid-July.