Tag Archives: Fallout

Designing a Nuclear Fallout Shelter

What does a nuclear fallout shelter actually look like? I had no idea, and so I did some research. Wikipedia covers the basics, but what I was really after were floor plans.

Unfortunately, there seem to be only two types of solution: Tiny home shelters with space for a handful of people for a few days, and huge cold-war era billion dollar projects built to shelter entire governments. There are a few exceptions, medium-sized bunkers built by wealthy individuals, but there is very little information about them available. As for floor plans… I found for pretty much nothing.

So I resorted to what I always do when I can’t (or don’t want to) find the genuine thing, I made a nuclear fallout shelter up from scratch. Please note that this is not supposed to be a design that “could actually work”, it’s just a baseline to have a consistent setting for the beginning of my NaNoWriMo 2008 novel.

A private fallout shelter would have to sustain its occupant for a minimum of two days, which some authorities consider the earliest acceptable time to leave a shelter at all, and only for evacuation to safer areas. The fall-out shelter would remain closed for two to three weeks – it would still be used for sleeping afterwards, but it seems to be the consensus that working outside is safe after 2-3 weeks.

The shelter would be built underground to provide the best possible protection from radiation. It’s designed as a safe refugee and fall out shelter, and less as a blast shelter.

Here’s a very rough floor plan design for the nuclear shelter:

The scale is probably a little off, and with the beds being bunk beds, ie. for two persons each, the shelter’s maximum of 18 occupants may require larger space for storage and sanitary necessities. Since bigger bunkers are a lot more costly, the shelter would be still as small as feasible, and occupants will be expected to stay in their bunks a lot of the time.

The rooms are not very high – I assume 2m ceiling height at the most.


I am not entirely sure how such a fallout shelter would handle water storage and waste disposal. I am assuming it uses a septic tank to dispose of excrements. Packaging won’t pose a problem, because everything that is consumed in the shelter has to be stored in the shelter when it is sealed anyway.


For the water supply, the shelter would likely have a large water tank and/or a pump to drain water from underground sources. 18 adult males, staying in the shelter for two weeks, would require over 930 liters of water just for drinking. Showers use anything between 4 and 12 liters per minute. The military recommends a minimum of one change of uniform and one shower per week to maintain health.

Shower water can be recycled to an extent; not only for flushing toilets, but there are actually techniques where a part of water used to shower once is recycled and used instead of fresh water for the next shower. Let’s assume 10 liters of water for this purpose, per person and week. I am not sure how to quantify water for cooking, but presumably this could be very little by using MRE’s. In total this works out to less than two cubic meters of water for two weeks, if I made no big mistake in my assumptions. Two cubic meters is something you can comfortably store, even if you double the capacity for safety and luxury. Even with a pump / well, the bunker would still store several day’s worth of water at least to cover for emergencies.

Since this particular bunker is located in the outskirts of a large city I am assuming a well is not practical.

Nuclear Fallout Shelter

Entrances and Exits

The airlock pictured in the floor plan is not something I envision as a “true” space-ship type airlock, but rather a way to minimize contamination of the inside – if a single door opens directly into the bunker, the wind is likely to blow particles inside. The outer door is much stronger than the inner one.

There is a small emergency exit on the other side of the shelter. It is not usable to bring equipment into or out of the bunker, and will only be used by the occupants to escape in case the main entrance becomes blocked.


The bunker’s energy is generated by a small diesel generator in a back room. The same room will have an exhaust to the outside. The ventilation system could be hand-powered in an emergency.


A battery-powered emergency lighting system serves as a back-up to prevent people stumbling for their flashlights in total darkness; besides, that same total darkness in an enclosed space could quickly lead to panic.

Other equipment

Naturally the bunker is equipped with Geiger counters, both actual Geiger counters capable of measuring small amounts of radiation, as well as civil defense radiological survey meters. There are hand-portable units as well as as units mounted outside.

There is a gasmask for every occupant.

Each room has a fire extinguisher and dual smoke detectors / CO detectors.

The shelter has a tv and a radio (with above ground antenna) in the main room, and ham radio in the generator room (not in the main room because communication may need to be private or censored).

It has a telephone line – expected to stop working in any real emergency, but the effort of adding it in is minimal and the possible benefit huge. It is also a convenience while the bunker is not in actual use.

Since they are small and incredibly useful, the bunker stores a couple of cheap notebook computers – if nothing else, video games and digital books can keep the occupants entertained. The shelter also has a selection of hard-copy books, both fiction and non-fiction “”how-to” style books.

The generator room is also equipped with a small work bench and stores a full set of tools and spare parts and materials.

Equipment is disconnected when not in use, and Faraday cages are used to protect some equipment against an EMP – just in case.

Anything else?

If I forgot something that I need for story purposes, it’ll be easy to add it in later. And if you think there’s something essentially wrong with the design… well, feel free to comment! It doesn’t have to be an actual working design, but it doesn’t hurt to flesh this out more, so others can use it for their own gaming or writing.