The reactor, already eight years behind schedule, is snagged on what Iran calls a politically motivated business dispute with longtime ally Russia.
Russia announced this month that construction would be delayed at least two months because Iran had failed to make monthly payments since January. It said the delay could cause "irreversible" damage to the project.
Because of the delay, Russia also indefinitely put off the delivery of enriched uranium fuel it had promised to provide Iran in March.
Iran, which denied falling behind in payments, was furious, convinced Russia was pressuring the country to bend to the U.N. Security Council, which has placed sanctions against it for refusing to suspend uranium enrichment.
Iranian lawmakers are now pushing for the country to ensure it does not need to rely on anyone.
"The pattern of Russia's behavior has strengthened Iran's determination to obtain the full technology to build nuclear power plants and end its dependence," conservative lawmaker Kazem Jalali said Saturday.
Rasoul Sediqi Bonabi, a nuclear scientist and independent lawmaker, added: "Russia has never been and will never be a reliable partner."
Due to have opened in 1999, the Bushehr reactor stands 95 percent complete, Iranian officials say. The facility, with its cream-colored reactor dome, overlooks the Persian Gulf and is heavily guarded, ringed with anti-aircraft guns and radar stations. Troops block roads leading to the site.
Construction began in 1974 with help from then-West Germany. Work was then interrupted during the 1979 Islamic revolution that toppled the pro-Western Shah Mohammad Reza Pahlavi and brought hard-line clerics to power. Iraq also bombed the plant during its 1980-88 war with Iran.
When Iran tried to resume the project after the war, the Germans refused to help. Iran signed deals with Argentina, Spain and other countries, only to see them canceled under U.S. pressure.
So Iran turned to Russia, signing a $1 billion contract to build the 1,000-megawatt Bushehr plant in 1995. That contract envisaged the reactor coming on stream in July 1999.
Iran's Atomic Energy Organization publicly complained Tuesday that Russia has postponed the launch five times.
"Even if the project is launched in September 2007, it will be eight years and three months behind schedule," it said. "The world has kept us waiting for more than three decades and spending several billion dollars more than any other nuclear power plant would cost without getting electricity," said political analyst Saeed Leilaz. Iran succeeded last year in enriching uranium for the first time at its enrichment facility outside the central city of Natanz. Now it is expanding the program to bring it up to a scale to produce fuel. The U.S. and its allies accuse Iran of intending to develop nuclear weapons. The top five powers at the U.N., plus Germany, have drawn up new sanctions to punish Iran for rejecting U.N. demands for a halt in uranium enrichment, a key process that can produce fuel for a reactor or the material for a nuclear warhead. Iran maintains its nuclear program is peaceful. The nuclear reactor outside the southern city of Bushehr is not part of Iran's dispute with the U.N. Security Council; the reactor itself has no potential military use. Despite the international pressure, Iran is also seeking to obtain technology to build and design other nuclear power plants. "We hope we will be among countries possessing technology to build nuclear power plants in the next few years," said Mohammad Saeedi, deputy head of Iran's Atomic Energy Organization. Iran is already building a 40-megawatt heavy water reactor in Arak, central Iran, based on domestic technology. It is also preparing to build a 360-megawatt nuclear power plant in Darkhovin, in southwestern Iran. Reformist lawmaker Noureddin Pirmoazzen said Iran's reactor ambitions will no doubt worry the West, although not as much as the enrichment program. "Any efforts by Iran to achieve nuclear proficiency will be opposed by the United States and other nuclear powers even if it is technology to build nuclear power plants," he said. AP-CS-03-17-07 1829EDT