“A nuclear weapon is a complicated object, but it is no longer a mysterious object to build. At this point it is possible to build a crude bomb, even with reduced efficiency and a certain probability that it will not explode, producing a nuclear reaction.”
To understand the effects of a low-functioning bomb, it is sufficient to remember August 6, 1945 at 8:16 a.m. Eight seconds and an untested device were sufficient to kill 140,000 people. This is without counting refugees and the fallout that contaminated the area for years.
“The Hiroshima bomb had 10 percent efficiency,” said Schaerf, “This means that it is sufficient for a nuclear bomb to explode for it to cause great damage. A Hiroshima bomb is essentially a sphere with a hole in the centre from which a sub-critical mass is shot, using an explosive charge, that unites with the other sub-critical mass forming a critical mass. This is done mainly with Uranium 235.”
“The problem,” he continued, “is not building the device in and of itself, but obtaining the material, which is 50 to 60 kg of Uranium 235, enriched above 80 percent to 90 percent purity.”
Uranium enrichment is the central issue of the Iranian question. In the currently operational plant, uranium is enriched at a percentage level useful for producing electricity, but uranium is enriched at 20 percent purity for medical purposes. In some cases it has been enriched to 27 percent purity, perhaps “an operational error.”
What is the danger threshold?
“Natural uranium is at 7 per 1,000, enriched to 4 percent purity it is reactor grade and above 80 percent to 90 percent it becomes bomb grade uranium. There are also old research reactors or submarine engines that use highly enriched uranium, but today they are no longer made. Acquiring highly enriched uranium is fundamental to building a bomb. What is Iran’s problem? The problem is that a plant that enriches from 7 per 1,000 to 4 percent can enrich up to 80 percent to 90 percent. It’s exactly the same technology. Every time the uranium goes through the machine, it is enriched by a certain amount. It’s enough to repeat the cycle. The more it is repeated, the more it is enriched. For every cycle it gains what in technical terms are known as separation units. It’s like washing clothes and removing stains on each wash cycle.”
Is the technology of the Islamic Republic adequate to accomplish these processes?
“Yes. The centrifuges used for civilian nuclear purposes are the same as those used for military purposes. It would eventually be possible to improve the process. That’s it. But there are no technological obstacles that impede enrichment of uranium to 90 percent purity. It’s only a political decision.”
And what are the time lines?
“It is an objective that can be reached in a reasonable amount of time, from six months to a year and a half, with plants already in existence. Optimists say that Iran wants to give the impression of wanting to become a nuclear power. The pessimists say Iran wants to become a nuclear power. The difference, therefore, is between the intention and the threat. As of today, Iran possesses a nuclear reactor at Bushehr and no major expansion programme. If building a reactor takes effectively ten years, what sense is there in beginning to enrich uranium now when it will be needed in ten years time? Additionally, Iran is an oil producer and exporter and does not fear an energy crisis.”
But Iran does not refine oil. It sells crude and buys refined products.
“This is true, but it costs less to build a refinery than to build a reactor and it provides far more secure energy. Therefore Iran has no industrial and economic reasons to refine uranium. Besides, it is a country experiencing an economic crisis that is wasting enormous resources to this end.”
The Iranian government has declared it will use enriched uranium for medical purposes.
“One doesn’t start a nuclear programme to build a reactor in a university. It would be uneconomical. Additionally, it isn’t necessary to just use uranium in oncology medicine. There are many radioactive nuclei that are far more efficient than uranium. On the other hand, heavy elements are poisonous. It is not an ideal solution. A nuclear programme is a politically prestigious programme.”
Now, a question for Carlo Schaerf in his role as president of ISODARCO. Can nuclear power be a deterrent?
It is a fact that nuclear war hasn’t broken out, but it is also a fact that we have been lucky because there have been many moments when we came very close.
There is a lot of anecdotal evidence ranging from the Cuban Missile Crisis to other less known incidents. Once, for example, U.S. missiles were put on the highest alert level because radar picked up a flight of geese over the Arctic.
In spite of the political climate between the U.S. and Russia, (the former USSR, editor’s note) being a lot more relaxed, missiles are still kept in a state of readiness. The risk of incidents, therefore, persists. For this reason it is important, in my opinion, to reduce the number of warheads. Going back to your question on deterrence, I remember in the 60s I was in the United States when Secretary of Defense Robert McNamara said that 600 bombs were a “reasonable deterrence.” Now we are up to 25,000. The excess is a status symbol, these are “psychological bombs.”
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Carlo Schaerf is a former Professor of Physics at the University of Rome “Tor Vergata” and was also a member of the Academic Senate of the University. He also previously held the position of Chairman of the National Committee for the Physical Sciences of the Ministry of Public Education and the National Committee for Nuclear Research of INFN (the National Institute for Nuclear Physics). Along with Professor Edoardo Amaldi, Professor Schaerf founded The International School on Disarmament and Research on Conflicts (ISODARCO). In 1970, Professor Schaerf served as Director in 1970 and in 1991, became the Chairman of the Board. He has edited over fifteen books on disarmament issues, authored over 100 articles in scientific journals and also the editor of 10 books on various topics on physics.