You Can Make a Nuclear Bomb Without a Mushroom Cloud [Tech Talk]

Pure Computer Simulation Replaces Nuclear Tests
Supercomputer Advances Lead to 'Algorithm Competition'
Nuclear Powers Find It Easier to Develop Stronger Warheads

The most crucial moment in nuclear weapons development is undoubtedly the nuclear test. This is natural, as it is the only way to verify whether a nuclear bomb, made solely based on nuclear fission theory, functions as intended. So far, nuclear powers around the world have conducted over 2,100 nuclear tests. North Korea even devised a new method called 'underground nuclear testing' to evade international monitoring.

Nuclear test. [Image source=Getty Images Bank]

However, nuclear testing and the arms race in atomic weapons have now entered a new phase. For the first time in history, nuclear powers have begun developing nuclear weapons solely through computer simulations instead of nuclear tests. This marks the moment when the nuclear arms race, which began during the Cold War, shifts into an algorithmic competition.

The World's First Nuclear Warhead Completed Without Nuclear Testing

Nuclear weapons are bombs that utilize energy released from nuclear fission or fusion. Although the principle has been well known for decades, major nuclear powers such as the United States, the United Kingdom, and France have invested astronomical budgets to increase the efficiency of fission and fusion, creating more powerful and safer warheads.

AEW (Atomic Weapons Establishment), the UK's nuclear weapons research and manufacturing complex. [Image source=Sky News capture]

Today, nuclear weapons are researched in cutting-edge scientific facilities. First, powerful lasers are fired at nuclear materials to simulate a nuclear explosion, and the moment is captured with ultra-precise radiation cameras. The data obtained is then transferred to supercomputers to conduct 'virtual nuclear tests.' However, with recent rapid advances in computer technology, the moment when virtual nuclear tests replace actual nuclear tests is imminent.

Nuclear missile submarine of the United Kingdom.
Photo by Yonhap News

Recently, the British government announced its nuclear weapons and atomic energy industry strategy. The report, which covers nuclear weapons, nuclear submarines, and small modular reactors, also includes plans for next-generation nuclear weapons research and development. The British government stated that it plans to manufacture the A27 'Astraia,' the world's first nuclear weapon developed purely through computer simulation, calling it "the world's first nuclear weapon produced without nuclear testing."

Supercomputer Advances Move Nuclear Testing into the Virtual Realm

The core of next-generation nuclear weapons development is the latest supercomputer 'Valiant,' introduced by the UK's nuclear weapons development division. Although detailed specifications and computational power remain classified, it is estimated to possess computational capabilities at the national top supercomputer level. Valiant is expected to perfectly reproduce the explosion moment of the Astraia warhead in the digital world.

A part of Orion, an advanced camera capturing the moment of nuclear fission. [Image source=AWE homepage]

The UK is not alone in aiming to develop nuclear weapons without nuclear testing. The U.S. Department of Defense, planning to introduce next-generation warheads in the 2030s, has previously stated that "in the future, nuclear warheads can be made solely through simulations." Additionally, the Los Alamos and Livermore laboratories, responsible for U.S. nuclear weapons research, completed a 3D spatial virtual simulation in 2022 that fully replicates a nuclear explosion.

The Nuclear Arms Race Transformed into an 'Algorithm Competition'

Ironically, virtual nuclear testing is likely to widen the gap between established nuclear powers and new nuclear weapon states. The advantage of virtual nuclear testing is that simulations can be run anytime without constraints of budget or location. As a result, nuclear scientists can discover models with higher energy efficiency.

On the other hand, countries lacking advanced laser facilities, cameras, and computers must still rely on real nuclear tests. North Korea, which conducted six underground nuclear detonations from 2006 to 2017, is a representative example. The United Nations (UN) signed the Comprehensive Nuclear-Test-Ban Treaty in 1996, and any country that carries out real nuclear tests faces strict economic sanctions from the international community.

Increasingly Powerful Nuclear Weapons

As the nuclear weapons development race shifts to an 'algorithm competition,' the destructive power of nuclear weapons will grow stronger. In fact, nuclear warheads have been continuously enhanced. The nuclear yield of the atomic bombs dropped by the U.S. military on Hiroshima and Nagasaki in 1945 was a mere 16 kilotons (kt, equivalent to 1,000 tons of TNT per kt).

Underground tunnel of North Korea's Punggye-ri nuclear test site being demolished in 2018
[Image source=Yonhap News]

Today, the maximum yield of nuclear warheads used by the U.S. Navy and the British Royal Navy exceeds 450 kt. Moreover, up to 14 such warheads can be loaded onto a single nuclear missile. Even the nuclear warheads tested by North Korea, which has far inferior technology, are estimated to have a yield of about 140 kt based on seismic wave measurements.

The yield of new nuclear warheads that the U.S. and the UK plan to introduce from the 2030s is classified, but they will be at least equivalent to or more powerful than those currently in use. Thanks to simulations, designing nuclear warheads with much higher yields has become easier.

Therefore, the 'algorithm competition' in nuclear armament is a double-edged sword for humanity. While concerns about environmental pollution caused by radioactive fallout have decreased, humans can now create more powerful atomic bombs at a much faster pace than before.

Of course, it is uncertain whether nuclear warheads developed purely through computer simulations will explode exactly as intended in reality. However, it would be better if the moment of finding out never comes.