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Scientists simulated a nuclear explosion on a major city - and how you might hope to survive it

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  • Scientists simulated a nuclear explosion on a major city - and how you might hope to survive it

    Scientists simulated a nuclear explosion on a major city - and how you might hope to survive it

    The study aims to offer advice on how people should take shelter if they are in a building which survives the blast itself, with three indoor locations identified as "critical" to avoid if you hope to survive.

    By Tom Acres, technology reporter

    Wednesday 18 January 2023 06:53, UK
    'Most dangerous' places to shelter indoors

    The researchers highlighted three places of notable danger when sheltering indoors: windows, corridors and doors.

    Ioannis Kokkinakis said these were the "most dangerous, critical indoor locations to avoid".

    "People should stay away from these locations and immediately take shelter," he warned.

    "Even in the front room facing the explosion, one can be safe from the high airspeeds if positioned at the corners of the wall facing the blast."

    The study's authors hope that understanding the impact of a nuclear explosion can help prevent injuries and guide rescue efforts, though they of course hope their advice will never be needed.



    Free Submitted: 29 October 2022 Accepted: 05 December 2022 Published Online: 17 January 2023

    Nuclear explosion impact on humans indoors featured

    Physics of Fluids 35, 016114 (2023);
    Ioannis W. Kokkinakisa) and Dimitris Drikakisb)

    This study investigates the nuclear blast effects on humans inside a building within a moderate damage zone. These effects depend on many parameters that must be better understood. In addition, the nuclear blast effects will spread further away than the devastating destruction zone, where most people are killed instantly. However, these injuries will vary depending on a person's position in the building and the air velocities attained when the blast wave enters indoors. The blast wave effects are examined for an indicative, easily reproducible indoor arrangement. The airspeed behind the blast wave accelerates to even higher velocities in the interior. The supersonic shock waves arising from the blast undergo expansion as they enter a room through an opening leading to channeling effects. The results show that most of the air is directed toward the corridor rather than through the opposite room's door, leading to high airspeed developed in rooms further down the aisle. The airspeed attained in the interior is calculated for two blast wave overpressures, 3 and 5 pounds per square inch, for which most concrete buildings do not collapse. The data reveal that the force applied to a standing person from the speed of the gusts formed at several locations in the interior is equivalent to several g-forces of body mass acceleration capable of lifting and throwing any person off the ground. It is then the impact onto solid surfaces that can lead to severe injury or death. Finally, the results reveal preferential areas in the rooms where a human can avoid the risk of exposure to the highest wind forces.


    We studied the impact of a nuclear blast corresponding to a 750 kT atomic warhead on humans indoors in a nuclear explosion's moderate damage zone (MDZ). MDZ is the area where concrete buildings may not collapse. At distances featuring overpressures of 5 psi, severe injuries and fatalities will be widespread, and damage to heavy structures will occur. At longer distances featuring an overpressure of 3 psi, severe human injuries and the destruction of smaller built-in structures will occur.

    The study revealed that the airspeed behind the blast wave induces significant forces on humans indoors. The most potent forces are experienced for a short period of up to half a second. The airspeed behind the blast wave accelerates indoors to even higher velocities. This stems from the expansion of the shock waves entering the space through an opening such as a window.
    Furthermore, channeling effects can further accelerate the air in the corridors.

    The force hitting a standing person indoors is equivalent to several g-forces of body mass acceleration and could lift a person off the ground and throw them to the walls. At an overpressure of 3 psi, the acceleration can reach 80 g, while at 5 psi, the acceleration exceeds 140 g. However, there are areas inside the rooms where the airspeed and the associated forces are reduced. The simulations provide colored maps of the indoor areas where the risk of human injury is reduced.

    Given the findings, the relevant authorities could issue instructions to prevent the nuclear blast from affecting humans situated indoors from the exposure to high-speed winds behind the incoming blast waves. Moreover, the results could guide the future design of concrete structures.

    "Safety and security don't just happen, they are the result of collective consensus and public investment. We owe our children, the most vulnerable citizens in our society, a life free of violence and fear."
    -Nelson Mandela