In a surprise move, Norbert Röttgen, German Minister for Environment, Nature Protection and Reactor Safety, announced "after extensive examination" that he will not grant an export license for the shipment of spent research reactor fuel to Russia. This reversed the earlier decision of the regulators to allow the shipment. In a press statement, dated 6 December 2010, Röttgen declared that "the condition prior to approval would be the proof that the fuel elements can be processed without harm in the Russian Mayak facility. The presented documents do presently not allow a concluding statement according to the criteria of the [German] Nuclear Law."

While the Minister's statement theoretically leaves the door open to resolve the issue at a later stage, the decision is seen as a highly political move at a moment when the German government is under increasing pressure by the environmental movement and its "political branch", the Green Party, over its decision to extend the operational lifetimes of the reactors and to start investigating the Gorleben site for its potential aptitude to serve as a final disposal site for high level waste. An unprecedented 50,000 people protested a recent shipment of vitrified high-level waste from the French La Hague reprocessing plant to the Gorleben intermediate storage facility.

The 951 irradiated fuel elements stem from the now shut down East-German research reactor in Rossendorf. They are stored in 18 Castor MTR2 containers in the intermediate storage facility at Ahaus since 2005. The same year the US, Russia and the IAEA (International Atomic Energy Agency) signed an agreement that allowed for the return and processing of high enriched uranium containing spent fuels. Removal of the HEU spent fuel from Germany was among the commitments made by Russia at the Nuclear Security Summit in April 2010. Funds for the transfer were provided by the U.S. GTRI program.

The Rossendorf fuel originates in Russia. The current owner is the German Land Saxony. The shipment license had been requested on 21 July 2010 by Nuclear Cargo + Service (NCS). On 23 September 2010, the Bundesamt für Strahlenschutz (BFS), the competent licensing authority, had authorized the shipment considering that all the legal requirements had been fulfilled. In a statement dated 7 December 2010, BFS has explicitly welcomed the BMU decision, mentioning radiation protection reasons in particular but "not only" reasons.

German environmentalists celebrate the BMU decision as success. The Green Group in the German Bundestag has released a statement congratulating the Minister: "After many mistaken nuclear policy decisions, for once Federal Environment Minister Norbert Röttgen has finally - even if it was late in the day - taken a right decision and prohibited the planned nuclear waste shipment to Russian Mayak. (...) The actions and protests against the shipments from Ahaus to Russia were successful".