According to an article published Thursday in the New York Times, "Iran has now produced roughly enough nuclear material to make, with added purification, a single atom bomb, according to nuclear experts."
Little physics here, folks.
ALL reactor fuel, with "added purification", can be used in a nuclear weapon.
It is the "added purification" which is the issue.
Is Iran actually doing "Added purification"? The IAEA says no. And it is not as trivial as the article implies. Nuclear fuel (what Iran is making) is enriched to 3%. Weapons-grade uranium needs to be enriched to 95% or higher. The required equipment, energy, and time needed to go from 3% to 95% is enormous, orders of magnitude larger than that needed for reactor fuel. And impossible to conceal (except under the Dimona reactor, which is, unlike Iran, safe from IAEA inspections.