The previously secret nuclear site has become a center for Iran’s nuclear activity because of the 2,700 centrifuges enriching uranium to the 20-percent level. The Islamic state says it is producing 20 percent uranium to make fuel for a research reactor in Tehran that produces medical isotopes. However, days after the recent failed talks with the International Atomic Energy Agency, Iranian officials announced the enrichment process will not stop even “for a moment.” 
 
 The regime’s uranium enrichment process takes place at two known sites: the Natanz facility with more than 10,000 centrifuges and Fordow with more than 2,700. In late 2011 the plant at Fordow began producing uranium enriched to 20 percent fissile purity, compared with the 3.5 percent level needed for nuclear energy plants. Buried 300 feet underground, the nuclear fortress at Fordow is immune to air strikes or bunker bombs. Tehran has repeatedly blamed Israel for a string of explosive disasters that have hit Iranian nuclear targets, including the death of Mostafa Ahmadi Roshan, one of Natanz's top nuclear scientists, killed when his car exploded in January last year. Three rounds of talks last year between Iran and the six powers - Russia, the United States, China, Britain, France and Germany - produced no breakthrough, increasing speculation Israel could attack Iranian nuclear installations.
– Iran today denied reports that an explosion had ripped through its Fordow nuclear site, which is buried 300 feet underground and considered safe from air strikes, the Telegraph and Reuters report. "The false news of an explosion at Fordow is Western propaganda ahead of nuclear negotiations to influence their process and outcome," state media quoted a nuclear official as saying. Seems the story started on a right-wing website called WND, which attributed it to an unnamed "former intelligence officer" in Iran—but that hasn't quelled speculation entirely. "Any explosion in Iran that doesn't hurt people but hurts its assets is welcome," said Israel's defense minister. And an Israeli foreign policy expert said Iran may have cooked up the story to keep inspectors from entering Fordow. After all, the story broke right after Iranian state media reported that talks could resume between Tehran and Western powers, although the EU quickly said no such agreement existed. Also note that Fordow started making uranium at 20% fissile purity in 2011, far higher than the 3.5% needed at nuclear energy plants.