The UN is basically a branch of the US State dept, so I would say this report is credible. But it's nothing new anyway. We all know Iran is NO THREAT to Israel and never will be even with a nuke. But the zionist/neocon fanatics have other plans for this world and naturally breed on misinformation and propaganda to get their way. See Iraq debacle.
Fire in Jerusalem suburb causes severe air pollution (Haaretz)
from the article: UN: Iranian uranium enrichment operating well below capacity