Israeli nuclear spy released
United States 10,000
China 400 (estimated)
United Kingdom 185
Israel 100 (estimated)
Source: Carnegie Institute
ASHKELON, Israel (CNN) -- A defiant Mordechai Vanunu has calmly walked out of prison after serving 18 years for spilling Israeli nuclear secrets to a British newspaper.
Sporting a dress shirt and tie and flashing V-for-victory signs alongside his brother Meir outside the Shikma Prison in the coastal city of Ashkelon, the former nuclear technician said he had no regrets over his actions.
"To all those calling me traitor, I am saying I am proud, I am proud and happy to do what I did," he said.
Vanunu was convicted of treason and espionage and spent most of his term in solitary confinement after providing the UK's The Sunday Times with information and pictures of Israel's secret nuclear reactor in the desert town of Dimona.
His revelations gave a clearer indication of Israel's secret nuclear program and led experts to conclude that Israel possessed the world's sixth-largest nuclear arsenal with around 100 atomic weapons.
Visibly angry, Vanunu said he suffered "cruel and barbaric treatment" at the hands of Israel's security services during his detention.
"I suffered here 18 years because I am a Christian ... if I was Jewish I wouldn't have this suffering and isolation."
The first stop for Vanunu, a 50-year-old Moroccan Jew who converted to Christianity, was to a nearby Anglican church where he was greeted by dozens of supporters.
Vanunu has said that all he wants to do after his release is leave Israel and try to resume his life.
But Israel -- where Vanunu is widely despised as a traitor -- is worried he could reveal more secrets and has banned him from leaving the country for 12 months.
Among other restrictions placed on Vanunu: he is unable to have a passport, can only have contacts with foreigners by permission for six months, is barred from foreign embassies, is not allowed to conduct media interviews and is forbidden to discuss nuclear secrets.
He also will be under close surveillance and must inform authorities of his movements.
However, Vanunu said he didn't have any more secrets to reveal and urged Israel open its reactor at Dimona to international inspections.
"The article was published; there are no more secrets. I am now ready to restart my life," he said.
"Israel doesn't need nuclear arms, especially now that all the Middles East is free from nuclear weapons."
I am a symbol of the will of freedom ... You cannot break the human spirit.
Israeli officials say the post-release restrictions on Vanunu could have been much tougher. They will be lifted if Vanunu toes the line.
"He promises to do as much damage and harm to Israel as he can," Israeli Justice Minister Joseph Lapid told CNN.
"He in this sense is a very, very unusual case where somebody spied on his country and betrayed his country and continues to do so and promises to do every harm that he can do to his country. So the sort of restrictions that we are imposing are very, very mild and moderate and limited."
Vanunu has also expressed concerns for his safety with some Israeli newspapers publishing the address in the Tel Aviv neighborhood of Jaffna where he was expected to live. It is now unclear where Vanunu will reside.
Vanunu became a technician in 1976 at Israel's Dimona Nuclear Reactor Center, where he signed a pledge to honor the Official Secrets Act.
He then secretly took photos inside the plant. At the same time, he was studying philosophy at Ben Gurion University, which many experts say contributed to a change in ideals.
By the time he was laid off from Dimona in 1985, Vanunu was feeling uncomfortable with Israel's nuclear secrets, his brother Meir said.
"He felt a duty -- according to what he said in the court, according to what he said in letters, and in my talks with him -- to speak about it to inform his own people and the international community," Meir Vanunu told CNN.
After moving to Australia, Vanunu met a Colombian journalist who encouraged him to tell his story.
Vanunu was in London for talks with The Sunday Times when he disappeared.
Shortly afterward, the newspaper published the photos of Dimona.
Two months later, while being taken into an Israeli court, Vanunu revealed how he was abducted and arrested by writing in black ink on his hand and showing it to photographers.
A file photo of the reactor at Dimona. Little else has been revealed.
He had been lured by a female Mossad agent to Rome, where he was drugged and smuggled back to Israel.
"He was extremely angry about that, and angry about the fact that they committed a crime but prevented him from speaking about it," Meir Vanunu said. "I was prevented from talking about it myself."
Convicted of treason and espionage at a closed trial, Vanunu was imprisoned for 18 years, the first 11 years and six months spent in solitary confinement.
Vanunu's admissions to The Sunday Times embarrassed Israel.
Rather than openly declare itself as a nuclear power, Israel still maintains a "strategic ambiguity" over its nuclear weapons capability.
Israel's military is believed to be capable of deploying nuclear weapons via fighter-bombers, land and submarine-launched missiles.
"We let you guess whatever you wish. What we have promised, and we keep the promise: We will not be the first to introduce nuclear weapons in the Middle East," Lapid said.
"But you must know that we are a country threatened to be annihilated by our enemies. We are the only country in the world which is threatened by annihilation. And therefore we have the full right, not only the right, we have the obligation to do the utmost to keep our security in best shape."
CNN Correspondents Walt Rodgers and Paula Hancocks contributed to this report