The French state energy giants bidding to take control of Britain's nuclear industry are facing concern over their safety record in France after the fourth radioactive incident of the summer.

The latest safety lapse occurred at a nuclear waste plant run by a subsidiary of Areva, the group which is leading a consortium in line to take over management of Sellafield in the UK.

Although the environmental impact of the leaks is limited, according to the French authorities, they have sapped confidence just as Paris is pushing to export its nuclear technology.

Areva, which is also seeking to design the next generation of British nuclear reactors, faced calls to shut down the plant at Tricastin in southern France after it was found to have emitted its annual quota of radioactive gas in just six months.

France's Nuclear Safety Authority ordered the company to stop activities resulting in carbon-14 releases until January after the failing, which involved the treatment of radioactive medical waste.

The authority added: “The impact of this discharge on the environment and the population has been judged very weak.”

But it was a further embarrassment to Anne Lauvergeon, Areva's chief executive, who is nicknamed Atomic Anne, following the overflow last month of about 75kg of untreated uranium at the same plant, which is next to the Tricastin reactor.

She initially dismissed the leak as an 'anomaly'.

But with locals having to avoid tap water and vineyard owners changing the name of their wine because Coteaux de Tricastin is now associated in Gallic minds with radioactive pollution, she admitted Areva had underestimated public fears.

Questions are also being asked about Areva's nuclear partner, EDF, the French state electricity group which hopes to take control of British Energy, after 115 of its staff were exposed to low level radiation in separate lapses at two of its power stations, including Tricastin.

The incidents have combined to give France's previously weak anti-nuclear lobby a stage from which to contest an industry which supplies 80 per of French electricity, the highest rate in the world.

Sortir Du Nucleeaire (Get Out of Nuclear Power) yesterday denounced Areva's radioactive emissions as 'very dangerous' and called for an official safety inspection of its factories.

Times Recommends

• Toyota recalls 437,000 cars including Lexus
• Myners says bonuses are bleeding pension funds
• Japanese company faked safety reports on seats