Experts have estimated that around 4,000 people will die from the effects of the 1986 accident at Chernobyl.
The Chernobyl plant is now encased in a concrete shell
The figure, in the report by the Chernobyl Forum, is much lower than other estimates.
It had been suggested tens or even hundreds of thousands of lives were at risk after the radiation leak at the plant.
The explosion, in Chernobyl's number four reactor, sent a radioactive cloud across Europe.
It was the largest nuclear accident in history.
The Chernobyl Forum was set up by a number of agencies including the IAEA, the World Health Organization, a number of UN bodies and the governments of Belarus, the Russian Federation and the Ukraine to look at the impact of Chernobyl.
It has examined scientific studies carried out for the report, which has been presented to the International Atomic Energy Authority's conference in Vienna.
From the moment the leak occurred, there were fears about the potential health effects on people exposed to radiation.
The report finds more than 600,000 people received high levels of exposure, including reactor staff, emergency and recovery personnel and residents of the nearby areas.
HOW MUCH RADIATION WERE PEOPLE EXPOSED TO?
Normal lifetime exposure to ionising radiation is 2.4 millisieverts (mSv) per year. Typical lifetime exposure is 100 to 700 mSv
Average Chernobyl-related doses between 1986 and 2005 have been between 10 and 20 mSv per year, although some have been exposed to hundreds of mSvs annually
People living in areas of India, Iran, China and Brazil with high levels of radioactive materials in the soil are exposed to around 25mSv per year with no apparent health effects
The predicted 4,000 death toll includes 50 emergency workers who died of acute radiation syndrome in 1986, and from other causes in later years; nine children who died from thyroid cancer and an estimated 3,940 people who could die from cancer as a result of radiation exposure.
The report says there is "no convincing evidence" that there has been a rise in other cancers because of Chernobyl.
It says confusion over the incident's impact has arisen because many emergency and recovery workers have died since 1986 from natural causes which cannot be attributed to radiation exposure.
It says: "Widespread expectations of ill health and a tendency to attribute all health problems to exposure to radiation have led local residents to assume that Chernobyl-related fatalities were much higher.
Since the accident, some 4,000 cases of thyroid cancer have been seen, mainly in individuals who were either children or adolescents at the time of the explosion.
Drinking milk from cows that ate contaminated grass has been identified as one of the main reasons for high levels of this cancer.
However, the vast majority of those diagnosed with the condition have survived.
The report warns the mental health effect of the accident on the local population was a significant concern, citing a number of studies which showed people around Chernobyl were affected by high anxiety levels and of unexplained physical symptoms.
But it said there was no evidence to show radiation exposure in the areas around Chernobyl had had any effect on fertility, pregnancy problems, stillbirths or the overall health of children.
Dr Burton Bennett, chairman of the Chernobyl Forum and an authority on radiation effects, said: "This was a very serious accident with major health consequences, especially for thousands of workers exposed in the early days who received very high radiation doses, and for the thousands more stricken with thyroid cancer.
"By and large, however, we have not found profound negative health impacts to the rest of the population in surrounding areas, nor have we found widespread contamination that would continue to pose a substantial threat to human health, within a few exceptional, restricted areas."
Melissa Fleming, of the IFEA, said the Chernobyl Forum report showed there was "finally a consensus" on the health and environmental consequences" of the explosion.
The report also concluded that, aside from a 30km (18 mile) area surrounding the site, radiation levels in the area had returned to acceptable levels.
However, it raised concerns about the condition of the concrete sarcophagus surrounding the damaged reactor and the disposal of radioactive waste from the accident.