In 2010, both the German and Belgian governments introduced reforms aimed at taxing fuels used for nuclear reactors.
Following a dispute, Engie Electrabel initiated arbitration proceedings against his German partner PreussenElektra – (an E.ON’s subsidiary) to define the amount of German and Belgian nuclear taxes to be passed on to each other. After a decision of the German Constitutional Court finding the tax unconstitutional, the debate focused on the Belgian nuclear tax. The arbitral tribunal ruled in PreussenElecktra’s favour, finding that they were not obliged to pay the belgian nuclear tax which amounted to €321 million.