How are Nuclear Weapons Tested? 

How and Why Scientists Have Tested the Most Dangerous Weapons Ever to Exist 

There have been over 2,000 nuclear weapons tested since the first bomb test in 1945 (1). Scientists perform these tests to gather data about a specific weapon to answer questions like “will the bomb go off?” and “what is the magnitude of the explosion?” 

To begin, a nuclear bomb is a high-power explosive device that uses nuclear fusion or nuclear fission. Nuclear fusion is when two light atom nuclei combine to form a heavier nucleus at high temperatures, producing nuclear energy. Nuclear fission is when the neutron of a radioactive element hits the nucleus of another atom, displacing the neutrons and causing a chain reaction with each nucleus collision releasing some energy (2). These collisions collectively release enormous amounts of energy, which are released in the explosion. The chained collision of the atoms gives the bombs a self-sustaining nature, part of what separates them from less advanced weaponry. Between the two processes, nuclear fusion is generally thought to be the more efficient one.

In the early years of nuclear weapon testing, scientists conducted controlled nuclear explosions above ground. These tests had significant downsides, as the surrounding area of the explosion was generally rendered uninhabitable because the bomb’s radiation contaminated the land (3). Soon after realizing these effects, scientists resorted to testing the bombs deep underground to hopefully prevent radiation. Still, the cavities and residual traces of radiation ultimately led most scientists to stop conducting explosion tests altogether. Now, there is a global taboo on nuclear weapon testing, with the last test being from North Korea in 2017 (4).  

Many countries have resorted to subcritical nuclear weapon testing instead of regular nuclear bomb testing. Subcritical weapons are tested around 1,000 feet below the surface and involve using special chemical explosives to heat specific nuclear elements, mainly Plutonium, to simulate an explosion. Unlike normal bombs, subcritical weapons don’t involve a self-sustaining nuclear reaction, making the explosions less hazardous and weaker, while also being safer for the environment (5). With all of this being said, caution must be exercised when discovering more about the potential of nuclear weapons. If countries return to testing their weapons on a large scale, tests could spiral out of control as countries attempt to gain further military potency. The following effects of these tests could be catastrophic to the environment and people alike.

Bibliography

1. ican. (n.d.). The Human Cost of Nuclear Testing. ICAN. https://www.icanw.org/nuclear_tests
2.  Campaign for Nuclear Disarmament. (2017). How do nuclear weapons work? – Campaign for Nuclear Disarmament. Campaign for Nuclear Disarmament. https://cnduk.org/how-do-nuclear-weapons-work/
3. Conover, E. (2026, January 6). Here’s the science behind nuclear weapons testing. Science News. http://sciencenews.org/article/nuclear-weapons-testing-explained-video
4. North Korea’s Nuclear Weapons and Missile Programs. (2025). Congress.gov. https://www.congress.gov/crs-product/IF10472
5. MSTS Editor. (2022, September 20). Smaller experiments, bigger discoveries: How subcritical experiments enable smarter stockpile stewardship – Nevada National Security Site. Nevada National Security Site. https://nnss.gov/news/article/smaller-experiments-bigger-discoveries-how-subcritical-experiments-enable-smarter-stockpile-stewardship/