Two representatives from an Iranian Resistance group known as the National Council of Resistance of Iran (NCRI) were at the National Press Club in Washington, DC to reveal the location of a top-secret nuclear site in the control of the Iranian regime. As negotiations between the U.S. and Iran are already at a highly controversial level, this highly charged, leaked information could affect those negotiations.
“Despite the Iranian regime’s claims that all of its enrichment activities are transparent and under the supervision of the International Atomic Energy Agency, it has in fact been engaged in research and development with advanced centrifuges at a secret nuclear site called Lavizan-3, in a military base in northeast Tehran suburbs.” 
This explosive discovery revealed publicly by NCRI came largely at the hands of a group that goes by the name People’s Mujahedin of Iran (MEK), which vehemently opposes the Iranian Regime of the Mullahs and has since 1989. Not to be confused with the Mujahideen in Afghanistan, MEK is made up of Shiite, left-wing nationalists and socialists.
Three years ago, it was revealed that MEK had been targeting Iranian nuclear scientists for assassination with the help of Israeli financing and training.
In short, if there is a group inside Iran that has a vested interest in helping to prevent the Iranian regime get nuclear weapons, MEK is one such group. During its presentation in Washington, NCRI insisted Iran is deceiving the international community and that the activity going on at Lavizan-3 can only be for the purpose nuclear weapons.
The question about what Iran would do with a nuclear weapon and who it might target first has been a topic of much discussion at Shoebat.com.
In late 2013, when the Obama administration’s sanctions strategy with Iran raised eyebrows, it was Saudi Arabia’s Prince Alwaleed bin Talal who expressed grave concern at the prospect of a nuclear Iran. Live-PR: http://www.live-pr.com/en/inu-tuesday-at-the-national-press-r1050564548.htm  NCR-Iran: http://ncr-iran.org/en/news/nuclear/17997-iranian-resistance-reveals-secret-nuclear-site-in-iran-used-for-uranium-enrichment-with-advanced-centrifuges