Via the Wall Street Journal:
The Obama administration initially demanded a complete dismantling of the nearly 20,000 centrifuges Iran has amassed to enrich uranium for the production of nuclear fuel. Tehran said it would ultimately need up to at least five times that number to have enough fuel to power the country’s reactors.
Iran denies it is seeking nuclear weapons and says its activities are for peaceful purposes only, such as the production of energy.
Signs of a potential compromise have emerged in recent days with Iranian state media reporting that Tehran and its negotiating partners, the five permanent members of the United Nations Security Council along with Germany—a diplomatic bloc known as the P5-+1—focused on a number of 4,000 centrifuges.
U.S. officials have neither confirmed nor denied the numbers. Outside experts said the number could be acceptable to the P5+1 and to Congress because it would place constraints on Iran’s ability to produce weapons-usable fuel.
“It’s not as simple as saying X-number of centrifuges, because it has to be taken as a whole package,” said another senior U.S. official. “We’re looking at all of the ways that we can basically block off any potential combination that they could think of how to get to a weapon.”
The White House’s outreach to Congress will be critical to sealing an agreement with Iran. The issue of Congress’s role is a contentious one.
The White House is arguing that an agreement wouldn’t be a formal treaty, and, therefore, wouldn’t require congressional approval. Leading U.S. lawmakers are threatening to impose new sanctions if a deal isn’t seen as doing enough to roll back Tehran’s nuclear capabilities.