Dr Khadduri left Iraq in 1998 and now lives in Canada
As part of a series marking 25 years since Israel bombed Iraq's Osirak nuclear reactor, former Iraqi nuclear scientist Dr Imad Khadduri speaks to the BBC News website:
We had just finished a day's shift work and were back at our homes around 1800 [1500 GMT] that day.
I heard the explosions all the way from my home, which is about 25km [16 miles] away.
I ran to the roof for a better view, and witnessed the smoke plumes rising from the area of the Tuwaitha Research Centre [where the Osirak reactor was located] and watched the Israeli planes flying west into the sunset.
It was immediately clear that they were Israeli airplanes.
The next day, we saw the extent of the damage. A few shift workers were injured.
Many of us had a lump in our throat for our shattered efforts as we began to clear some of the rubble.
Until Israel's attack, we were only dabbling with some calculations relating to nuclear fuel burn-up and criticality calculations - nothing sophisticated and focused.
After the Israeli attack, we discussed among ourselves our gut reaction that a political decision would now come forth ordering us to make the bomb. Soon enough, it did.
We were psychologically ready for it. We embarked upon it full-heartedly. Investment and resources were heavily poured into the programme over the next 10 years.
That period saw attempts being made in the following scientific and technical areas, which are all part of a nuclear weapon programme:
- research projects in uranium enrichment or plutonium production from spent nuclear fuel
UN inspectors visit a ruined Iraqi uranium enrichment site in the 1990s
- exact manufacturing techniques for the casting of the core of the bomb
- a workable design for the bomb itself with accurate explosive lenses
- a suitable design for enabling the bomb to be carried in a long-range rocket head
- a sophisticated command and control system for the guidance, delivery, release and detonation of the bomb
Iraq managed exceedingly well in hiding the scope of its programme from foreign intelligence eyes - whether it was Mossad, the CIA or MI6 - until after the 1991 [Gulf] war.
When the IAEA [International Atomic Energy Agency] inspectors arrived they finally managed to put the pieces of the programme together on the ground, but only over a period of one year after that war.
Iran is now in a much better position, after learning from Iraq's experiences in its nuclear weapon programme.
It is more prepared, in terms of tight security and deep covertness, than was Iraq in hiding the critical aspects of its nuclear weapon programme from foreign intelligence.
A tight security apparatus and tight control - like that in Iraq during the 1980s when it engaged fully in its nuclear weapon programme - ensures Iran against actual spies roaming around, or inside, its nuclear establishments.
That would be the only reliable source on the scope of their programme.
Interview taken by Patrick Jackson, BBC News