Crashing a jet into a nuclear reactor helped officials prepare for the worst

You can never be too careful.
Interesting Engineering
An F-4 Phantom jet slamming into facility walls.Sandia Laboratories

Reinforced concrete is strong — to test that fact, the U.S. government once decided to crash a jet into a slab of it. An F4 Phantom jet, to be exact, slamming into the material at roughly 500 mph (804.6 km/h).

While it seems like a bizarre waste of a good plane, the 1988 experiment had a clear purpose. The government was concerned about the strength of the material, as it was used to construct nuclear reactor facilities. Checking whether a plane would survive crashing into the sides could help protect against a nuclear meltdown — the Soviet Union's Chernobyl disaster was only two years prior.

Ever since the first nuclear power plant went live back on June 26, 1954, in Obninsk, Russia, the world has feared a devastating accident or terrorist attack could spark an apocalyptic event. While there have been a couple of incidents which caused nuclear reactors to leak radiation, the accidents were never a result of terrorist activity. The lack of human-imposed damage is largely due to the fact that many government agencies have developed impeccably tough walls to keep radiation in and keep terrorists out.

Can reinforced concrete stop a jet going 500 MPH?

Sandia Laboratories examined the strength of reinforced concrete by launching a fully-loaded F-4 Phantom jet directly at a massive slab of concrete to investigate the survivability of a nuclear power plant in the event of a terrorist attack. The following clip shows the incredible experiment.

Miraculously, the concrete block survived almost completely unscathed. The test aimed to investigate the impact of a jet onto a piece of reinforced concrete measuring 12 feet (3.66 meters) thick. The aircraft of choice is a fully functional F-4 Phantom. It was loaded onto a rocket sled track and was accelerated up to 480 mph, or about 770 km/h where it slammed directly into a slab of reinforced concrete. The jet did not contain jet fuel but was rather filled with water. The test did not look to examine the damage of an ensuing fire.

The jet was traveling so fast upon impact; it shatterd into millions of tiny pieces. The only section which remained intact was the small section of the wing which missed the target entirely. While the video is mesmerizing in its magnificent deconstruction, the resulting damage to the concrete block is surprisingly minuscule.

The damage left behind the nuclear reactor was merely a scratch

The maximum scar depth was 2.36 inches (60 mm) at a maximum. The structural damage sustained was merely a scratch. However, the force launched the block back nearl 6 ft (1.82 m). Nevertheless, behind the impact remained an incredibly high-energy impact. As the engine exploded into tiny fragments, it experienced an acceleration force of more than 700 times the force of Earth's gravity.

While the experiment looks incredibly devastating, it proves reinforced concrete can easily stop a jet from inflicting serious damage to a nuclear reactor. Although not all factors were examined during the experiment, it is important to note the many more safety precautions government officials take to ensure the security of the reactor and the people of the country.

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