An airborne survey of gamma radiation sources around the Pickering and Darlington nuclear stations in Toronto, Ontario found normal levels outside the plants.
The $200,000 survey was conducted last fall for Ontario Power Generation, the provincial company that owns the facilities, to check whether any radiation from the two atomic plants had spread into neighbouring communities.
Environmentalists have dismissed the results, saying large gamma ray sources are not found around nuclear stations unless they have had a severe accident that ruptures containment systems.
The group wants Ontario Power to reduce routine emissions of tritium, which emits a form of radiation that wasn't measured in the survey.