Report: Iran reduced its nuclear weapons ability

VIENNA -- The United Nations will release a report this week certifying that Iran's ability to make a nuclear bomb has been greatly reduced because it has diluted half of its material that can be turned quickly into weapons-grade uranium, diplomats said Tuesday.

The move is part of Iran's commitments under a deal with six world powers in effect since January that mandates nuclear concessions from Tehran in exchange for a partial lifting of sanctions crippling its economy.

A key concern for the six was Iran's stockpile of 20-percent enriched uranium, which is only a technical step away from the 90-percent grade used to arm nuclear weapons. By late last year, Iran had already amassed almost enough of the 20-percent grade for one nuclear bomb, with further enrichment.

Under the agreement, Iran agreed to halt its 20-percent enrichment program and to turn half of its nearly 440-pound stockpile into oxide for reactor fuel. It also pledged to dilute the other half into low-enriched uranium.

Making weapons-grade uranium by reconverting from oxide or from the lower level would take much longer than doing so from the 20-percent enriched material, giving more time for the international community to react. Iran says it is not interested in nuclear weapons but is negotiating because it wants to end all sanctions.

The U.N. nuclear agency is due this week to report on Iran's adherence to the deal and two diplomats said it would say Iran has fulfilled its dilution commitment while continuing the process of conversion into oxide.

Iran has until June to fulfill all of its commitments under the deal. But it has to show progress in exchange for sanctions relief, and one of the diplomats said it apparently decided to complete dilution now because it was eager to get its hand on the next tranche of $4.2 billion of oil revenue funds frozen under international sanctions meant to force it into nuclear compromise.

The two are familiar with Iran's adherence to its commitments. They demanded anonymity because they were not authorized to discuss the confidential International Atomic Energy Agency report.

The November agreement between Iran and the six -- the United States, Russia, China, Britain, France and Germany -- is meant to lead into a comprehensive deal placing long-term caps on Iran's enrichment program and other atomic activities in exchange for sanctions relief.