(Adds arrival of uranium in Russia, U.S. and IAEA officials) By Louis Charbonneau DRESDEN, Germany, Dec 18 (Reuters) - Russian experts working by night removed a large quantity of highly enriched uranium from a Soviet-era reactor in Germany on Monday and flew it to Russia for processing. Anti-nuclear protesters forced a convoy carrying the material to stop briefly despite efforts to keep the route secret and a heavy police presence. Some 326 kg (717 lb) of enriched uranium, enough for several bombs, was heading to a processing centre in Podolsk, Russia from the former Rossendorf research reactor near Dresden, where the material was stored, U.S. and German officials said. Moscow's atomic energy agency Rosatom said in a statement on its website that the shipment had arrived in Russia. Roughly two-thirds of the uranium is highly enriched. In Russia it will be mixed with low-grade uranium to make reactor fuel that no longer represents a proliferation risk. "This action is an important step towards promoting a global cleanout of HEU (highly enriched uranium) in the civilian sector," said Arnaud Atger, a senior official at the U.N.'s International Atomic Energy Agency (IAEA) in Vienna. "The security of HEU is of particular concern due to the technical feasibility of constructing a crude nuclear explosive device from HEU," he told reporters. Atger, along with colleagues from the U.S. National Nuclear Security Administration (NNSA), assisted the Russians. The U.S. official charged with helping Russia and the IAEA recover enriched uranium around the world, NNSA Assistant Deputy Administrator Andrew Bieniawski, also welcomed the transport as a blow to any terrorist plans to acquire atomic weapons. "Every kilogram of material that is moved is one less kilogram that could be used by terrorists to make a bomb," he told Reuters. "The total amount of 326 kg is the largest ever shipment ever done under our programme." Bieniawski said Washington had spent some $25 million to upgrade the Podolsk plant processing the HEU to help make it "one of the most secure facilities in Russia and the world." The U.S-Russian nuclear material recovery programme is two years old and is called the Global Threat Reduction Initiative. GLOBAL STOCKPILES OF ENRICHED URANIUM The Rossendorf reactor was built by the Soviet Union in communist East Germany and remains a key site for scientific research. The reactor was shut down in the early 1990s. Nuclear experts estimate there are some 1,850 tonnes of highly enriched uranium in global stockpiles. As many as 500 uniformed German police and more undercover officers provided security for the transport from the forested Rossendorf research centre to Dresden airport, police said. A convoy of around 40 police vehicles escorted the silver armoured truck carrying the uranium on its pre-dawn 10-km (6-mile) journey to a waiting Ilyushin 76 Russian cargo plane. Security officials kept the route for the journey secret and dispatched a second decoy convoy to confuse anti-nuclear protesters. But 20 to 30 activists still managed to find the right one and force it to stop briefly and change route. "The nuclear material should be kept in Dresden, because such transports always involve risks," Tobias Muenchmeyer, a Greenpeace nuclear expert, told Reuters television. Rossendorf officials said all precautions had been taken to ensure security of the material, even if the plane had crashed. The German state of Saxony paid for Monday's shipment. The United States funded all previous such operations.
