The landmark Joint Comprehensive Plan of Action (JCPOA) agreed in 2015 between Iran and major world powers was intended to prevent the development of a nuclear weapon. However, US President Donald Trump’s decision to unilaterally withdraw from the deal last May and re-impose harsh sanctions on the country unravelled the agreement, which limited Iranian scientists from enriching uranium beyond a certain percentage. Tehran announced in May that it will be withdrawing from key elements of the deal over time – starting with the limit on uranium enrichment.
It has led to questions over how close Iran actually is to developing a nuclear weapon of their own, and how uranium enrichment can lead to the eventuality.
The Iranians maintain that they intend to use their uranium stockpile to fuel nuclear power plants – but countries like the US and Israel have always doubted this.
The uranium used in nuclear reactors is usually enriched to 4 percent.
The JCPOA limited Iran to enrichment of 3.67 percent – well below the 90 percent usually required to create a nuclear bomb.
However, Iran’s breach means they could reach that level in the near future.
On a technical level, the hard work has already been done if Iran truly seeks a nuclear weapon – because more than half the effort needed to reach the 90 percent level is spent getting to 4 percent.
Once uranium is enriched to 20 percent – which Tehran has done previously – only a tenth of the work remains.
Tehran’s decision to surpass the 300kg limit of uranium hexaflouride – equivalent to 202.8kg of low-enriched uranium – stoked further fears that Iran will accumulate enough highly-enriched uranium to produce a nuclear warhead.
The process streamlines itself as the material gets more refined and less has to be moved about.
Nuclear nonproliferation specialist Anne Harrington said: “It’s really hard at the start because you have very, very little of the uranium isotope you want.
“Natural uranium is almost all U-238 and initially getting that little bit of U-235 out is really difficult.
“But the more refined you make it the faster the refinement process happens.”
However, various nuclear experts doubt that Iran, even if they were to reach the limit, would develop a nuclear bomb.
Ms Harrington added: “Even once Iran crosses the 300kg threshold, they are still a long way off from having a stockpile sufficient to produce a bomb.
“At 3.67 percent, they would need to stockpile approximately three times the current limit to have enough material for one bomb, and that material would need to be further enriched.”
She added that instead of developing a weapon, Iran’s breach signals a desire to assert Iranian sovereignty over their own actions.
Meanwhile, security expert Jan Ruzicka noted: “This could clearly see this escalating further into something nasty and dangerous.
“But does this get Iran closer to the bomb?
“Technically speaking, yes in some ways, but it’s still a way to go from where they are — even if they overstep this threshold.
“It’s significant, yes, but dangerous I’d say potentially not immediately with a view to the nuclear bomb.”
Currently, the US, Russia, Britain, France, China, India, Pakistan, North Korea and Israel possess nuclear warheads.
Supreme Leader Ayatollah Khamanei issued a religious ruling in 2005 that the production, stockpiling and use of nuclear weapons are forbidden under Islam.
Iran has maintained its insistence that it can enrich uranium for peaceful purposes.