BRUSSELS (Reuters) - Belgium may have breached EU law in extending the life of two nuclear reactors because it failed to carry out a full assessment of the environmental impact, an adviser to the European Union’s top court said on Thursday.

Slideshow ( 2 images )

However, the Belgian authorities may be able to keep the reactors running while they rectify their procedural error, the advisor said in a recommendation to judges who will eventually rule on the case.

Reactors Doel 1 and 2 near Antwerp were scheduled to cease production in 2015, but the Belgian government decided in that year to extend their lives by 10 years.

Two environmental groups brought an action to Belgium’s constitutional court seeking an annulment of that decision because no environmental assessment had taken place. The Belgian court sought the advice of the European Court of Justice.

Juliane Kokott, an advocate general of the EU court, said there were grounds for taking the view that the Belgian law to extend the lives of the reactors had been enacted without a necessary environmental study.

Opinions of the advocate general are not binding, but are followed by the EU court in most cases.

Engie Electrabel, the Belgian arm of French utility Engie that operates the reactors, noted that the opinion did not rule out that the reactors could remain running.

Sara Van Dyck, energy policy adviser at Bond Beter Leefmilieu, one of the groups that brought the action, said that while the opinion was a bit confusing, the group was happy with the advice in general.

The Doel 1 and 2 reactors have been offline since April since a leak in Doel 1’s water cooling system was discovered.

Both reactors are under repair as Belgium faces a tight electricity supply situation going into winter with just two out of its seven nuclear reactors working.