TEHRAN (Reuters) - Iran marked "nuclear technology day" on Saturday by saying it had improved the equipment used to enrich uranium -- the process which many Western countries fear Iran is using to try to produce a nuclear bomb.
The annual celebration of its nuclear programme was overshadowed this year by the delay in starting up Iran's first nuclear power station, a project begun in the 1970s, because of a technical problem in the reactor core.
Earlier on Saturday, Foreign Minister Ali Akbar Salehi confirmed that fuel rods which had been inserted into the reactor last October, but were then removed, were now being reloaded after being cleaned. He said Bushehr should reach its "critical phase" by May 5-10.
Tehran says its nuclear programme is entirely peaceful and has dismissed international sanctions that were tightened last year as illegal and ineffective.
Talks with global powers aimed at resolving the nuclear impasse stalled in January, with Tehran insisting it would not accept any curb on its nuclear enrichment activities.
President Mahmoud Ahmadinejad used his speech to delegates at the nuclear day conference to stress the symbolic importance of Tehran having its own civil nuclear capacity, comparing the West's attempts to curb it to the hostile British and U.S. reaction to Iran's nationalization of its oil industry in the 1950s.
"If we should evaluate Iran's achievements in the nuclear field, it might exceed the nationalization of the oil industry in importance. Back then, more important than the oil itself was the independence and the honor of the nation," he said.
Fereidoun Abbasi, the head of Iran's Atomic Energy Agency told the conference that "second and third generation" centrifuges -- the machines which enrich uranium to a purity needed in nuclear reactors, or even up to nuclear weapons grade -- had been produced and tested, the official IRNA news agency reported.
He said two assembly lines had now been established at the Natanz enrichment site in central Iran producing uranium enriched to 20 percent purity -- much more potent than the level needed for nuclear fuel but still not pure enough for weapons material.
(Reporting by Hashem Kalantari and Ramin Mostafavi; Writing by Robin Pomeroy; Editing by Mike Nesbit)