On behalf of 11,000 workers in the nuclear industry, Prospect said the tenth report by the Committee on Medical Aspects of Radiation in the Environment had given nuclear power stations a clean bill of health.

"This proves conclusively that there is no connection between living in proximity to nuclear power stations and incidence of childhood cancer," said Mike Graham, Prospect national secretary. "This is very good news for the public and our members who work or live near nuclear power stations."

The COMARE study into 32,000 cases of childhood cancer between 1969-93 is the largest such study ever carried out. The data is still being analysed but it shows no evidence of increased risk of childhood cancer within a 25km radius of any nuclear power station.

COMARE did find evidence of a higher than expected incidence around some nuclear sites, but when the figures are corrected for other known factors such as affluence, regional variations and other potential causes, the increased incidence of leukaemias disappears except at Sellafield and Dounreay. For these sites, COMARE confirmed that the number of cases was so small they could not be directly attributed to any one causal effect and could be the result of statistical chance.

Professor Bryn Bridges, COMARE chairman, indicated that the database of cancers showed that the variability of incidence across Great Britain as a whole did not exceed 5%, making it likely that the highest levels of cancer would be reported at locations remote from any nuclear plant.

The tenth COMARE report of childhood cancer incidence was produced on a nationwide basis to enable patterns identified in earlier reports around nuclear sites to be seen in the context of patterns in the rest of the UK.

Prospect represents scientists, engineers, managers and specialists at British Nuclear Fuels, the UK Atomic Energy Authority, British Energy, the Atomic Weapons Establishment, the Devonport and Rosyth dockyards and other nuclear installations.