The release occurred between July 23-24 at Cattenom, located near Thionville in northern France, when 15,300 gallons of relatively harmless hydrochloric acid leaked from the tap of an acid tank, the French nuclear safety agency ASN announced last week.
The chemical -- used for anti-scaling treatment within one of the 1,300 megawatt plant's four nuclear reactors -- was flushed out through an above-ground wastewater pipe, but it was discovered the pipe had a gap in it. Instead of being transferred to the cooling tower, the effluent seeped into the ground.
Some of that material was recovered from the groundwater and released into the Moselle River through regular sewer pipes, with plant operator EDF initiating a groundwater monitoring program outside the plant.
EDF downplayed the incident, saying the acid spill represented no danger to the public and would present few problems outside the immediate site. ASN concurred, classifying the event as a zero on the seven-point International Nuclear Event Scale.
The incident was the latest of more than 750 recorded at Cattenom since its commissioning in 1986 and came after a transformer fire in June -- the same month the plant was singled out for criticism by ASN after undergoing three incidents in 10 days.
The agency's official explanation about the July 23-24 incident wasn't issued until Tuesday, and no word was forthcoming from EDF at the time of the event, rankling some in Luxembourg, 20 miles away from the plant.
There are no nuclear power plants in Luxembourg and Cattenom's construction in the 1980s was staunchly opposed in the country. The Luxembourg Parliament unanimously adopted a motion last year stating that Cattenom "threatens the sovereignty and sustainability of the Luxembourg nation," and demanding "the strengthening of government action to [attain its] permanent closure," Le Monde reported.
The daily newspaper Luxemburger Wort editorialized Friday the acid leak posed "worrying questions" and asked how it was possible that a significant amount of material could escape from the plant "simply because of a missing a piece of pipe."
It also showed problems with EDF's "communication policy thinking," since the event wasn't disclosed at the time, the newspaper said.
The French plant and its problems have become a political issue in the nearby German state of Saarland in the run-up to national elections next month, where members of the Green and Social Democratic parties criticized German Environment Minister Peter Altmaier for not demanding it be shut down.
In a published interview last week, Altmaier called such demands "frivolous" and indicated he would make so such request of France, triggering harsh criticism from local Green and SPD politicians, broadcaster Saarlandischer Rundfunk reported.
Member of Parliament Simone Peter, Saarland's Green Party leader, said Cattenom would only be safe "if they shut down immediately," asserting it has major design flaws, while SPD MP Mark Tressel accused Altmaier -- a member of the Chancellor Angela Merkel's Christian Democratic Union -- of not using his office to lobby for the safety of the Saarland.
In the Bundestag, the CDU has been leaning toward making a request, while the CDU in Saar have called for the shutdown of Cattenom, he told the broadcaster.