Quitting the NPT will do Iran no good at this point, only harm. No longer will Iran be able to buy nuclear power plants (like Bushehr) from Russia and other countries, nor will it be able to get cooperation from abroad on building research nuclear plants. Indeed, this will take away from Russia the motivation to protect her nuclear client Iran and make the Russians amenable to more severe UN sanctions. It is best for Iran to continue their game playing with the IAEA while becoming more able to design power plants on their own.
Yemen's Houthi rebels commit to peace plan in letter to UN chief, BBC reports (Haaretz)
from the article: Iran pushes foward plan to review ties with UN nuclear watchdog