French Polynesian officials and test veteran groups have been told former French nuclear weapons test sites in the South Pacific are stable.
The assessment was presented in Papeete to a commission which is part of an information process launched three years ago.
The update said that radioactivity is stable or decreasing.
According to the public broadcaster in French Polynesia, the exception are sediments containing plutonium in the lagoon of Fangataufa and Moruroa.
Sensors on the two former test sites suggest there is no risk of the atolls collapsing because of the damage caused by the blasts.
Atmospheric readings on seven islands, including Tahiti, Hao and Hiva Oa, show readings lower than those in mainland France.
Between 1966 and 1996 France tested 193 nuclear weapons in the South Pacific.