Diplomats gathering in Vienna will seek a compromise over an Iranian reactor that could produce weapons ingredients when they resume talks on the Islamic Republic’s nuclear program today. European Union foreign policy chief Catherine Ashton and Iranian Foreign Minister Mohammad Javad Zarif will join diplomats from China , France , Germany , Russia, the U.K. and U.S. The sides have set a target of July 20 for a permanent accord after breaking a decade-long deadlock in Geneva last year. After the last round of talks in March, Russia called on Iran to “demonstrate goodwill” by finding a way to modify the Arak heavy-water reactor and allay concerns that it can produce plutonium, a key ingredient in nuclear weapons. Robert Einhorn, a former U.S. negotiator, said in a report for the Brookings Institution that Iran should convert the project into a light-water reactor that wouldn’t produce plutonium. Princeton University researchers […]