4 Things You Need to Know  To Survive Nuclear Fallout

4 Things You Need to Know To Survive Nuclear Fallout

by Matthew Collins

Hiroshima. Chernobyl. Nagasaki. Fukushima. They’re practically household names at this point.

As such, most people know that the consequences of the radioactive fallout spread far beyond the borders of these towns and cities. What you may not realize, however, is just how far.

In some cases, the consequences might seem trivial. Take, for example, the lack of salad greens throughout France for months following the Chernobyl disaster.

Meanwhile, the black rain following the atomic blasts at Hiroshima and Nagasaki, were clearly devastating.

In this regard, radioactive fallout can be elusive—taking a ruinous toll on some, while others are left seemingly untouched.

Either way, the most important point to remember is that fallout is the inevitable result of practically any major nuclear event. It doesn’t matter whether you’re talking about a meltdown at one of the world’s 450 active nuclear facilities, a terrorist attack with a dirty bomb, or full-scale nuclear war: fallout will be a fact of life for anyone in the surrounding area.

The silver lining? Radioactive fallout isn’t nearly as instantaneous, destructive, and unpredictable as a nuclear blast or meltdown. Indeed, it is something that you can prepare for—something you can work around and navigate your way through.

So in this post, we’re going to take a deeper look at the nature of nuclear fallout.

This means we're going to look at the science behind it, the basics of how fallout works, the situations that can arise, and the challenges you may face in the event of a nuclear disaster.

We will also pay close attention to prevailing wind patterns and geography, allowing us to gauge how much radioactive fallout you would potentially be exposed to during a nuclear attack or disaster.

And perhaps most importantly, we’re going to touch on a few basic things that you can easily do in order to prepare forand ultimately surviveshort-term exposure to nuclear fallout as you make your way to safety.

For the roughly 100 million Americans living within the fallout zone of an active nuclear reactor, this could be an important read.

So let’s get started…


  • 01

    Fallout 101

  • 02

    Survive the First 72 Hours

  • 03

    Prepare for the Worst

  • 04

    Knowledge Is Power

  • 05

    Frequently Asked Questions

Fallout 101

As the name clearly implies, the definition of nuclear fallout is any residual radioactive material that falls out of the sky in the aftermath of a nuclear blast, meltdown or other critical event. If that sounds like common sense, it's because it is.

What few people appreciate, however, is the true magnitude of nuclear events—or the massive amounts of toxic fallout they can produce. After all, there are a few key things that nuclear bombs and meltdowns both do exceptionally well:


Pulverizing material over a wide area, nuclear events can create a tremendous amount of debris, ash, and particulates. These rapidly increase exposure for those in the immediate area—where the highest concentrations of fallout and radiation can be found. In a subterranean explosion, called a “base surge,” this phenomenon is even more pronouncedwith an effect akin to that of an active volcano.


Nuclear events irradiate this pulverized material, creating an unintentional but extremely toxic concentration of debris, dust, ash, and fallout—all while local residents are most likely seeking medical attention or escape.


Finally, nuclear events propel the radioactive material into the stratosphere. In fact, in some cases, nuclear events can contaminate entire wind patterns with high concentrations of irradiated fallout. That’s how these events have lasting—albeit mildereffects hundreds or thousands of miles away.

These forces work together to produce a synergistic effect that maximizes victims' exposure to toxic elements. Ergo, even and especially those who survive the initial blast can expect to face an absolute nightmare situation in terms of exposure to radiation.

When it comes to determining the extent and volume of fallout following any particular nuclear event, there are two key factors to consider…

First, there’s the location of the explosion. If it’s an airburst, then comparatively little fallout will be produced (but there will be a substantial EMP wave). However, if it’s a surface explosion, material will actually be pulled up into the nuclear cloud and irradiated before it’s carried along the plume into the upper atmosphere.

Consequently, you might think an explosion over water would be more favorable—but that’s just not the case.

You see, the explosion evaporates water and irradiates the remaining sea salt, producing much finer and smaller radioactive particles that can spread across a much larger area. This fallout can then seed clouds and rain back down on cities hundreds or even thousands of miles away.

And it goes without saying that this fallout won’t simply wash off the outside of a building. Indeed, water surface bursts can even pulverize the sea floor. During the infamous Castle Bravo nuclear test, for instance, where a massive chain reaction was accidentally triggered due to the bomb’s peculiar construction, it was reported that calcinated white powder (pulverized coral) rained down on nearby boats.

Subsurface bursts, meanwhile, become even more complicated, because the base surge they produce can flood the surrounding areas with lethal doses of radiation before the fallout even arrives.

The second key factor is meteorological. Though it’s frightening to think that something as devastating as nuclear fallout is determined by the way the wind blows, that, we're afraid, is exactly the case. This means that, due to the fine particulates produced by a nuclear blast, fallout can easily be carried over hundreds of miles in a matter of hours and days.

Of course, the greatest intensity of the fallout is felt in the immediate area of the nuclear event, but radioactive materials can nevertheless spread far and wide due to its volatile nature.

Part of this is accomplished through the animal kingdom. For livestock who graze in fields covered in nuclear fallout, for instance, their radioactive diet might prompt their extermination (as in Chernobyl). In other instances, however, they may spread the fallout further by carrying it in their fur, droppings, and bodies.

Vegetation is a concern here, too. After all, crops can be dusted with fallout from an explosion hundreds of miles away, as was the case with the French salad greens mentioned above. These plants typically have to be safely destroyed to contain exposure.

But ultimately, the nature of exposure, how it works, and what constitutes a lethal dose of radiation—these things are still widely debated and little understood. But, when it comes to fallout, there are a few things that can be said for certain:

Fallout isn’t always predictable, it’s got devastating potential, and knowing what to expect can provide a crucial advantage at a time when most people will still be reeling.

Surviving the First 72 Hours

Facing the reality of a nuclear detonation (and the fallout that comes with it) might feel overwhelming to think about. With that said, it’s far from being a hopeless scenario.

Consider Akiko Takakura, for example, who was just 300 meters from ground zero at the Hiroshima explosion, but survived unscathed. Eizo Nomura, meanwhile, was even closer, at just 155 meters from the hypocenter. That means he stood less than two football fields from a nuclear explosion, and still lived well into his eighties.

This, of course, raises the question: how did they survive a nuclear bomb going off right on top of them, while so many others perished? In reality, there are four key factors that will determine whether you’re safe from the fallout of a nuclear detonation or meltdown:


As we’ll cover in just a moment, time is crucial after a nuclear blast. You’ll only have about fifteen minutes to seek sufficient cover, but radiation will die down to acceptable levels in most of the blast area after just a few days. Note that fallout is at its absolute worst in the first 72 hours, so it’s crucial to evacuate immediately or stay sheltered. After a few weeks, you’ll be able to make longer trips outside (if you haven’t yet evacuated).


While there are a handful of cases like those mentioned above, close proximity to a nuclear blast and the immediate fallout tend to spell certain disaster. So while it makes sense to shelter in place during the worst of the fallout, your ultimate goal will be to put a safe distance between you and the bomb’s lingering radioactive effects.


In an instant, the initial fireball and scorching thermal radioactive material of a nuclear detonation gives way to what’s called gamma radiation. Gamma radiation is notoriously powerful, able to penetrate inches of heavy material (even thick lead plating) and rapidly poison the body, so shielding can play a vital role in protecting you from radiation. Notably, both of the Hiroshima survivors mentioned above were underground in a shielded concrete basement, which was the key to their survival.


Radioactive materials decay at different rates, which can affect everything from timing and distance to the amount of shielding needed to protect yourself.

Here, it's worth noting that each of these factors interacts with the others. So if you’ve got a robust enough shelter, you won’t have to worry so much about distance. Likewise if you enter an area weeks after the fallout has dissipated.

In recent years, Americans are starting to pay much closer attention to these kinds of considerations. In fact, just a few years ago, the New York Times ran an article called How to Build a Fallout Shelter. What this shows is that these kinds of considerations are hardly Cold War relics.

In that spirit, let’s take a look at how you might really survive a modern nuclear event.

First things first: if you’re exposed to a nuclear detonation or meltdown, it will be a hard thing to miss. You’ll either see it, hear about it on the news, take note of a special nuclear fallout alarm, or catch on as those around you react to what’s going on.

In the first crucial minutes, your very first priority will be finding the best possible shelter nearby. This is because you’ll have about fifteen minutes or less to do so. Remember that cars provide absolutely no protection, and that any (indoor) shelter is better than being outside.

Once you’ve found the right place, go to the deepest room inside it. You’re basically trying to put as many walls as possible between you and the outside world, even if that means holing up in a linen closet. Note that you’ll want to make sure you’re away from doors, windows, and anything else that might be exposed to the outside world.

It’s even a good idea to tape up the cracks around doors and windows, to prevent particulates from seeping in.


Reasons to Remain Calm in the Event of a Nuclear Disaster

  • First, most modern nuclear weapons have a blast zone of about one mile. For meltdowns, the most severe area of exposure will be even smaller. If you’re outside this small radius, you’ve already dodged the greatest risk of fatality.

  • After the initial blast, you’ll have about fifteen minutes to seek shelter before the fallout begins to set in. This gives you enough time to find the best possible shelter in the immediate area without exposure.

  • It might seem ideal to have a hazmat suit and expensive kit on hand at this point, but the best thing is good old-fashioned shelter--namely concrete. Ultimately, that’s the best protection for those first crucial days.

  • While fallout and the aftermath of a major nuclear detonation will obviously last for years, you should be through the absolute worst of it in just 72 hours.

Once you’re confident in your shelter, you’ll want to gather supplies. We’ll talk more later about which supplies are best to keep on hand (ideally you’ve got a bug-out bag), but you’ll want to lay hands on as much food, water, and other essentials as you can find without leaving your shelter. Once the fallout sets in, it won’t be safe to eat anything (even packaged food) from outside your shelter.

It’s also a good idea to take a shower, if possible, and change clothes, as this ensures that you’re not wearing fallout in your shelter. The same holds true for any pets that were outsidegive them a good wash to minimize radiation exposure. After that, waiting is the name of the game.

Note that in the immediate aftermath of a nuclear explosion, radiation levels will typically be extreme, and fallout will be at its worst. This is when you’re most likely to see effects like the black rain that came down on Hiroshima after the nuclear explosion there.

Fortunately, the worst of this fallout will dissipate quickly. In some cases, radiation levels can drop from as much as 1,000 roentgens/hour to as little as 10 roentgens/hour in just the first three days. That’s why it’s so crucial to stay inside, away from windows and doors, during the entire first 72 hours.

This is where a radio can come in handy, giving you a crucial lifeline to the outside world. After all, for the next 72 hours, you’re going to want to stay buried as deep as possible in your shelter while the intensity of radiation outside plummets to more liveable levels.

After that, in many cases it should be safe for short trips outside. Of course, there’s no guarantee, as each nuclear event plays out differently. Regardless, by the 72-hour mark, you can start thinking about making your way to safety or at least assessing your surroundings.

Here, it's important to stress that even if the nuclear event doesn’t happen in your immediate areaeven if it’s hundreds of miles awaythe fallout could still potentially reach you in a day or less. So even if you’re just watching the news about a nuclear event on television, don't hesitate to start making preparations.

Prepare for the Worst

When preparing for something like a major nuclear event (and the fallout that comes with it), you run the risk of preparing in a manner that’s either too specific or too broad to be truly helpful. So instead, it’s best to break things down to their components—then focus on doing the best job with each individual component.

For example, it’s generally a great idea to stock up on food and water. This is especially useful in the event of nuclear fallout, because the more food and water you have, the longer you’ll be able to stick to your shelter and avoid the radiation outside. Ideally, you’ll want at least a two week supply of food and water on hand.

If and when that food is depleted, you’ll need an escape plan to get you to safety. If you’re in a city, that might mean making it to the country. Or if you’re on the coast, it might entail driving to a family cabin in the mountains.

Regardless of your exit strategy, it’s important to have one, whilst keeping a few backups in case things don’t go exactly to plan.

MIRA Safety CM-6M CBRN Mask

Since any realistic exit strategy will have you leaving your home after a few days, weeks, or months, it’s prudent to stock up on hazmat gear as well. MIRA Safety’s HAZSUIT, CM-6M mask, and NBC-77 SOF filter all have a long shelf life and can be paired with Kappler chemtape, tough chemical-resistant gloves, and overboots for complete protection.

NBC-77 SOF Canister Filter

While it might be tempting to save a few dollars on your hazmat gear, it’s important to remember that not all suits are created equal. Ultra-cheap suits, for instance, can easily be punctured, exposing you to dangerous elements. Military suits, meanwhile, feature carbon lining and breathable composition, but they can be prohibitively expensive or hard to find (something we’re working on improving). Our HAZSUIT, on the other hand, strikes a nice compromise between the two, with reliable puncture-resistant performance and an appealing price point.

HAZ-Suit Hazmat Protection Suit

It’s also great to keep an emergency package around for storms, blizzards, hurricanes or tornadoes. That kit should include a crank-style emergency radio, basic first aid kit, matches, flashlights, and other basic utilities. Once again, these are all great tools to have on hand in case of nuclear warespecially the radio.

Some folks will even go as far as to prepare a special fallout room/nuclear war shelter, reinforcing walls with wood, concrete, bricks, and sand to thicken barriers and cut down on possible radiation.

While this might seem like overkill, a few minor considerations can actually upgrade an existing storm/hurricane shelter to something that would increase your odds of surviving a nuclear event. Plus, even just a few inches of barrier could provide much needed protection from the gamma radiation mentioned above. In the end, there's a wealth of knowledge to consult online, and there are plenty of contractors who would be willing to work with you on a custom setup.

Perhaps the most specific preparation for nuclear fallout should be in your bug-out bag. After all, you may be at work, school, or otherwise away from home when a nuclear event occurs—in which case a bug-out bag is a crucial lifeline to get you to safety.

That’s why there are a few must-have items we recommend for everyone’s bug-out bag:

Thyrosafe tablets

Thyrosafe tablets are a cheap and east purchase—and one of the items most likely to save your life. But how do they work? Well, these powerful pills flood your thyroid with safe iodine, enough to keep your system from absorbing any for the next 24 hours. This is crucial, because radioactive iodine (I-131) is a major factor in nuclear fallout, accumulating in your thyroid and rapidly poisoning the rest your body with radiation. One little pill, however, has the power to stop that process dead in its tracks.

A reliable gas mask

A reliable gas mask, like the MIRA Safety CM-6M or military-grade CM-7M full-face gas mask, is a bug-out bag must-have. Although dangerous radiation can pierce concrete with ease, radioactive particles can still be extremely dangerous, especially in the immediate aftermath of a nuclear explosion. There might also be fires and chemical or biological elements in the environment. While a gas mask is only part of a larger system of personal protective equipment (PPE), it remains a staple, as it's highly mobile, easy to carry, and can save your life in the right circumstances.

A gas mask filter

To filter out that radioactive iodine, you'll need a gas mask filter that's reactor-rated. In this regard, the MIRA Safety NBC-77 SOF filter is a great choice, because it also provides protection against a number of other chemical, biological, and radiological threats while having a twenty-year shelf life and lightweight construction.

An emergency radio

Even if you’ve already got one at home, an emergency radio is well-worth the investment. After all, when hunkering down in a shelter, there’s a good chance that cell phones and standard phone lines will go down, but emergency radio broadcasts will let you know whether it’s safe to go outside. Note that these things cost just a few bucks, they’re compact, and they can be just as much of a lifesaver as the Thyrosafe tablets.

Whatever else fits

Lastly, pack whatever else fits, including a hazmat suit and chemtape for sealing things up. Granted, these inclusions won’t necessarily be practical in most bug-out bags—indeed, it might be a better idea to just double down on your food supplies. Nonetheless, a hazmat suit and chemtape can be helpful for navigating the environment after you survive the first 72 hours. A gas mask, however, is a definite must-have, because it can be carried with ease and donned in a matter of seconds, while a hazmat suit can take substantially longer to deploy.

Of course, this is all in addition to what you might already have in your standard bug-out bag—but it shouldn’t add too much weight. Note that MIRA Safety even offers a special package that includes a gas mask, filter, Thyrosafe tablets, and a drop-leg pouch to store it all.

Regardless, these key preparations are easy to makeand potentially extremely useful in other situations as well (particularly in relation to the gas mask).

Knowledge is Power

We understand that the prospect of surviving the aftermath of a nuclear event is rather daunting. Hopefully, however, it seems a bit less overwhelming than it did just a few minutes ago.

Make no mistake—it would still almost certainly be the single most challenging day of your life. And a variety of factors will inevitably remain well outside of your control. However, with a bit of careful preparation and consideration, you can vastly increase your own odds of surviving the nightmare of a nuclear explosion and attendant fallout.

Remember: it’s all about those crucial first 72 hours. From the first fifteen minutes to those first three days, simple decisions could have massive consequences for your survival. So find the safest possible shelter, hunker down, and wait out the worst of the radiation.

Granted, even after everything we’ve covered, even after preparation and planning, you’ve still got to be ready in case things go awry. So, what will you do if your primary shelter is suddenly out of the question? What if you don’t have a bug-out bag handy?

Preparing for multiple contingencies with layered plans can further improve your chances of survival and help you adapt to challenges on the fly. Therefore, be sure to identify good shelter locations near the places you spend most of your time, and stock up on backups wherever possible.

There are a number of great resources on fallout, radiation exposure, and the science behind it all at ready.gov and CDC.gov, so feel free to do as much additional research as you’ve got time for. One day, you may be glad you did.


Frequently Asked Questions

How do you prepare for nuclear war?
When is it safe to go outside after a nuclear bomb?
Could you survive a fallout?
How long does nuclear fallout last?