Prominent conservative lawmaker Alaeddin Boroujerdi said Iran won't ship its low enriched uranium abroad in a single batch or in several shipments, a compromise suggested by some government officials, under any circumstances.
"Nothing will be given of the 1,200 kilograms (of low enriched uranium) ... to the other side in exchange for 20 percent enriched fuel, not in one batch nor in several. It is out of question," the semiofficial ISNA news agency quoted Boroujerdi as saying Saturday.
The UN-brokered plan required Iran to send 1.2 tons (1,100 kilograms) of low-enriched uranium
- around 70 percent of its stockpile - to Russia in one batch by the end of the year, easing concerns the material would be used for a bomb.
After further enrichment in Russia, France would convert the uranium into fuel rods that would be returned to Iran for use in a reactor in Tehran that produces medical isotopes. Fuel rods cannot be further enriched into weapons-grade material.
Earlier, Iran had indicated that it may agree to send only "part" of its stockpile in several shipments. Should the talks fail to help Iran obtain the fuel from abroad, Iran has threatened to enrich uranium to the higher level needed to power the research reactor itself domestically.
The Tehran research reactor needs uranium enriched to about 20 percent, higher than the 3.5 percent-enriched uranium Iran is producing for a nuclear power plant it plans to build in southwestern Iran. Enriching uranium to even higher levels can produce weapons-grade materials.
The United States and its allies are unlikely to accept anything substantially less than the original plan, which aimed to delay Iran's potential ability of making nuclear weapons by at least a year by divesting Iran of most of its enriched uranium and returning it as research reactor fuel.
On Saturday, Russian President Dmitry Medvedev signaled that Moscow could back sanctions against Iran if it fails to take a constructive stance in international talks over its nuclear program.
He told the German magazine Der Spiegel that it would be better to avoid sanctions, but they can't be excluded if there is no progress in the talks.
If 70 percent of Iran's uranium is exported in one shipment - or at the most two shipments in quick succession
- Tehran would need about a year to produce enough uranium to again have the stockpile it needs for a weapon.