The operators of the Kashiwazaki-Kariwa power station – the largest nuclear power station in the world in terms of electrical output – have admitted there were leakages of radioactive material.
But the Tokyo Electric Power Company, which runs the plant, says there is no danger to the public.
The visit follows a request by the government of Japan’s central Nigita region, where Kashiwazaki-Kariwa is situated. Tokyo initially said no international inspection was necessary and refused to approach the IAEA.
Niigata officials said bringing in outside experts would help to damp down rumours that the radiation leaks had been more serious than admitted.
Unease arose when the leaks were found to have been much bigger than first estimated.
The power company has said getting the plant running again could take some time because contaminated water needs to be cleaned up first and dozens of other problems need to be fixed.
The magnitude 6.8 earthquake struck in mid-July and caused more than 50 malfunctions at the Kashiwazaki-Kariwa plant.
The quake killed 10 people and injured hundreds.