The Likely effect of a Nuclear Attack

Light & Intense Heat

A nuclear explosion will blind you if you look directly at detonation point. There is immense heat and light. The heat cause buildings to spontaneously combust up to 2 miles away! Skin will be burnt and melted! If your Shelter survives the initial detonation, then it should protect against the heat! Any part of the Shelter made by combustible material will be destroyed!

Initial Nuclear Radiation (INR)

This penetrating radiation is emitted from the fireball almost immediately. INR extends to just under 2 miles, so anyone within this range in a Shelter will require that Shelter to be protected from INR! That's the real reason why fallout bunkers are necessary, not just to protect from the blast, but to protect from the penetrating radiation! The nuclear bunkers we offer will protect you from this devastating radiation. In years gone by they used to be as an atomic bunker, but they are just as crucial now as they were during the Cold War!

Blast Pressure Waves

At detonation the resulting blast travels as a 'pressure wave' giving birth to devastating winds! This blast wave moves over the gradient of the land and causes structures to implode due to the increased pressure overhead!

Tremors and Earthquakes

The initial blast will devastate all buildings within about 2 miles. Tremors (or ground disturbances similar to an Earthquake) would not extend beyond this range! Factors on whether or not subsurface Shelters will actually survive Tremors depend on their ability to move with the Tremors, and the type f soil its buried in! Deeper depth, flexible materials used in Shelter construction and its Design also factors....

Fallout Dust

A 'ground burst' detonation sucks up shrapnel and material from beneath, this is then vaporized and becomes radioactive! It re-forms as particles and falls to the Earth on the wind. This is called fallout, and can fall anywhere from ground zero - hundreds of miles out! It can be seen as a light coloured dust, but gives out lethal radiation which is invisible. Radiation can kill. This dust remains lethal for several days after detonation, but should really not be considered safe to touch for several months at least!

Bombs Detonating at Ground Level (Ground Burst)

A 'ground burst' creates a devastating shaking of the ground. The Earth that is destroyed and totally consumed by the mushroom cloud leaves a big crater in the ground. The re-formed Earth starts falling to Earth after half and hour, but can take as long as 2 days! This is radioactive fallout!

Fig 1

Bombs Detonating at Altitude (Air Burst)

A nuclear bomb detonating in the air is called an 'air burst'. The effect is more remarkable. The area of devastation is a third greater than a comparable bomb exploding on the surface! There is however, no fallout (as no debris is sucked up, no debris can fall to Earth).

Fig 2

Fig 3 - The Range of: Blast Pressure Wave, Fireball and Initial Nuclear Radiation (INR) Destructive Reach.....

Air burst (1 megaton)

Fig 3a

Ground burst (1 megaton)

Fig 3 b

A Total destruction x Approx. range of INR within which shielding is vital z Blistering to exposed skin
B Irreparable damage y Fire zone
C Severe/moderate damage

            What happens to fallout after a nuclear attack

Radiation emitted from fallout dust decreases over time, this decrease in radiation is accelerated at first but slows down as time passes. IE - at 7 hours, the radiation will have fallen to 1/10 (10%, or 1 tenth) of its original strength, at 2 days its down to 1/100 (1 hundredth). You have to wait until this radiation has fallen to relatively safe levels before you can emerge from your Bunker! Make a radio available so you can find out when it is safe to emerge and for how long! You may be told it is safe to spend 1 hour or so a day outside, but even then I wouldn't go out! Some of the more devastated regions may require a stay of 2 weeks, other less affected areas may only require a few days Shelter, but we at Bunker Shield always recommend a stay of one month MINIMUM!

When it is safe to go outside you do not need NBC (Nuclear, Biological and Chemical  suits! However, it is a good idea to keep outdoor clothes, and indoor clothes separate. Change clothes every time you come and go from the Shelter! 

Our Bunker's provide various levels of resistance to Blast Pressure Waves and fallout radiation. They should also resist fire, as long as you haven't used combustible materials in the construction (particularly in the above ground Shelters). There isn't any Bunker that can withstand detonation at Ground Zero, but if you survive the mushroom clouds, the factor you need fear the most is radiation fallout. That is where our Bunkers come in, and they WILL save your life! 

The Shelters that offer the most protection form fallout radiation are the ones that use dense materials in their construction. The more of this dense material you use, the better the resistance to external radiation. Different materials have different levels of effectiveness!

On the table below I have listed everyday materials that could possibly be used in building your Shelter! Their relative effectiveness at stopping radiation by 1 half is shown in terms of material thickness required to achieve this. So, for example, 2.2 Inches of Concrete give the same level of effectiveness as 3.3 Inches of Earth!

This effectiveness at stopping radiation is known as the Protective Factor (or, PF). Your average house will reduce the dosage of radiation 1/15 (1 fifteenth). So you would call this a Protective Factor of 15 (or, PF 15).  Obviously our Shelters provide many hundreds of times more Protection than this due to the density of materials we use!

Some relative protection values
Inches Inches
LEAD 0.5 STONE 2.2 Increased thicknesses of material reduce the intensity of Ionizing radiation. For example, each 2.2 in. of concrete reduces the intensity by half, so a thickness of 8.8 in. of concrete would reduce the radiation to one sixteenth of its original intensity.
TILES 1.0 to 1.9 SAND 2.9
2.0 EARTH 3.3


Here is a more visual representation of this effectiveness of differing materials. The graphic shows how much density various materials need to be to offer the same level of protection against radiation.   Four Inches of Lead will provide the same protection as 3 Feet of Soil (which happens to be the most cheapest, and readily available) option also! :-

The overall picture

In the event of a nuclear war, ultimately the types of warheads used will differ. Some will be 'air burst', while others will be 'ground burst' detonations. Either way, it is estimated 5% of the United Kingdom would be devastated from Blast Pressure Waves. Obviously, no-one knows exactly where detonations would occur, however logically we can estimate that major populations centre's would be targeted. Up to 80% of the land might not suffer from Blast Pressure Waves at all. Shelters are still necessary though (even if they are not near the detonation zones) as radiation will fall all over the British Isles and those not in a Shelter will suffer from permanent disfigurement due to radiation sickness, pass those defects on to their unborn children or die!


                    Circles of Devastation: A Key to the Nukemap Data

The following statistics represent the 100 MT Russian Tsar Bomba.  The largest man made explosion ever designed.

    • Fallout Radiation Area:  5 miles                                                                                                                   500 rads 50% - 90% death rates just from initial exposure; death can take anywhere between a few hours to weeks!
    • Air blast Area: 8 miles
      20 PSI from Blast Pressure Wave; Complete destruction. Nearly everyone killed.
    • Air blast radius: 21 miles
      5 PSI from Blast Pressure Wave; structural failure in most buildings, everyone injured and most people dead
    • Thermal radiation radius: 48 miles
      Everyone experiences 3rd degree burns, all combustible material ignites, thermal fire zone

    • Fireball radius: 2 miles
      Extent of 'mushroom' cloud firestorm; severity of effects depends on whether it is a ground burst warhead, or an airburst warhead


This picture, taken from the Nukemap, shows the level of destruction that would be caused if the Tsar Bomba - the largest USSR bomb designed - was dropped on London

This picture, taken from the Nukemap, shows the level of destruction that would be caused if the Tsar Bomba - the largest USSR bomb designed - was dropped on London

A wider view shows just how apocalyptic the circle of destruction would be

A wider view shows just how apocalyptic the circle of destruction would be



        Types of Shelters

The following table illustrates the 4 Shelter Types that Bunker Shield installs! It also compares protection variations and site locations. It is up to you if you want to use different materials, as long as you use the comparative Data given above so that the Protection Factor (PF) isn't diluted! Bunker Shield is professional in its approach to Construction and we use qualified Contractors with years of experience in this field. 

Please note, of the following examples of shelter, only Type 4 will enable survival within 2 miles of the blast site. Most of population in Britain will be within 2 miles of a blast site! Radiation spreads out about 5 miles, this alone would kill 90% of population within that 5 mile radius not protected by Bunkers! You MUST stay inside your Bunker for at LEAST 2 weeks after detonation to avoid lethal radiation exposure. I would recommend staying inside for 1 month, and have supplies to last at lease that long (if not longer).


Bunker T1 (a) and T1 (b)
Home Made

Bunker T2 
Basement Bunker

Bunker T3 
Pre-Fabricated Subsurface Shelter

Bunker T4 
Professional Construction (Bunker Shield specialises in these)

Blast Pressure Wave(PSI) resisted before structural failure results!

1.5 psi

6 psi

11 psi

Over 11 psi

Protection Factor

(reduction of radiation)

PF 40

PF 70

PF 200

More than PF 300

(Initial Nuclear Radiation also resisted)

Range of Bunker survivability

(based on a 1 MT airburst detonation)

No closer than 7 miles out from detonation

No closer than 3 miles out from detonation

No closer than 2 miles out from detonation

Closer than 2 miles out from detonation (this really depends on Bunker customisation, protection features and specifications)

Type of Air Supply

Pipe to outside

(at 90 degree angle)

Pipe to outside

(at 90 degree angle)  or

Kearny Air Pump

Kearny Air Pump

Kearny Air Pump

Placement of Bunker

Inside house or Outside Yard

In basement

Buried in Yard

Deep subsurface construction in Yard. Major modifications required (although will be hidden when finished)

When should Bunker Type be constructed?

At very short notice!

Can be constructed relatively quickly

At very short notice!

Can be constructed relatively quickly

At relatively short notice!

May take longer to construct than Bunker Types 1 (a), 1 (b) and 2!

Long term notice!

Requires foresight, planning and professional construction. This all takes time!

Estimated construction expense (2010 prices)


[not including labour, surveyor and professional costs]


[not including labour, surveyor and professional costs]

Kit £9,310.00+

[not including labour, surveyor and professional costs]

£51,700.00 - £125,000 (Communal Bunkers, Luxurious Bunkers, and Bunkers with a lot of extra 'military style' protection, will have a greater expense)

[Including labour, surveyor and professional costs]


Planning permission, Building Regulations and rating

Before thinking about installing a Shelter, check local government regulations before submitting plans or breaking the surface of your ground! Your local government authority will inform you if planning permission is required. The rateable value of your home MAY alter the Council rates of your home, simply because the value will increase by an estimated 4%! This is for the District Valuation Officer to decide  (Regional Assessor in Scotland).


There is an exemption from Building Regulations and Planning Permission as long as the following apply:

  1. Internal Floor area no more than 30 sq metres (322.92 Sq Ft),
  2. Depth is no greater than the distance to the nearest building, and
  3. It is a subsurface Type 4 Shelter, and not one of our 'above surface' models!

In those circumstances you do not have to submit plans. Tell your neighbours that it is water pipe maintenance, or else you run the risk of them trying to force their way into the Shelter during times of crisis!



       Blast and Fallout Concerns

The Blast Pressure Wave create winds which travel as fast as 2,000 mph within half a mile, would be 1,000 mph up to 2 miles out, and will be at hurricane levels, or 200 mph, 7 - 9 miles out! If you don't know an attack or detonation is imminent, then your only chance is diving for cover the minute an ultra brilliant light appears on the horizon! 

If you see this ultra brilliant light, drop, duck and cover (DDC)! Then, immediately head for your Bomb Shelter! The fallout radiation dust will start to fall in as little as 5 minutes (depending on your distance from the detonation point) and will be lethal if you are exposed to it for as long as 5 - 10 minutes! This initial radiation will be so intense that it could penetrate your car, home and all other buildings (including several Inches of Concrete).

If your underground bomb shelter is buried with its ceiling covered with 3 Feet of soil then this will be enough to reduce the effects of this deadly radiation. If you get to your bomb shelter within 5 - 10 minutes of the detonation, you will most likely survive. If you don't, its goodbye cruel World, and hello Heaven or Hell! If you are caught out in the open, but are AT LEAST 10 miles away from the detonation point, you will most likely survive the Blast Pressure Wave! However, even at this relatively safe distance, radioactive fallout dust will fall within half an hour! If you don't therefore find Shelter within half an hour, your death will come in an hour. If your Shelter is 10 miles away from the attack, it is said a few days in there is enough. I would say no matter where you are in the UK, stay inside for a month! 

Bunker Shields 'Type 2' basement Bunkers, will reduce the outside radiation by 100 - 200 times!  So, for example, if the Initial Radiation Intensity (INR) was a very lethal 500 R/hour (death comes within an hour at this level), your basement Bunker will reduce this radiation to 5 R/hour. You will survive these levels. Remember also that the radiation intensity will decrease as tie goes by. Up to 99% of that lethal INR will dissipate within 2 days!  

The radioactive fallout gives off so much positively charged energy which decimates living tissue cells, yet this same excitable energy burns itself out more quickly. At detonation point, up to an hour after the event, fallout will be devastating. The fallout levels would be 1000 R/hour. In half an hour your dead just from this alone! However, even this very excitable radiation energy would be down to 100 R/hour after only 7 hours, and 43 R/hour after 14 hours!  

Nuclear Fallout Time Effects

The effect of radiation burning itself out is illustrated above (and below). Its known as the '7-10 rule'!  For every 7x older the radiation fallout becomes, then the radiation has decayed to 1/10 of its original strength! That means that after the initial 7 hours, 90% of the radiation (known as gamma radiation) has dissipated! Then, of the remaining 10% of radiation that is left, 90% of that will be gone after 2 days have passed! This is why the 'naysayers' who say that Shelter building is a waste of time are very wrong! Getting to your Shelter quickly WILL save your life! Shelter building and preparation should be considered and acted upon now by anyone who has the ability. You never know when your time to prepare will run out......  

The 7-10 Rule illustration below :-


*NB - The above illustrations & decay rates only apply to devices common to the Military (such as Fusion & Fission devices),  and does not apply to  "Dirty Bomb's", commonly referred to as  RDD's (Radiological Dispersal Device's). This is because RDD's are more likely to be used by Terrorist's, who would only be able to source common commercial isotopes (used in industry). These isotopes would most likely include : nuclear power plant rods, Cobalt 60, and Cesium 137. The drawback with these commercial isotopes is that they all have longer half lives! The good side of this though  is that the contaminated area will not as be as widespread. The drawback is that long term Sheltering won't be a possibility due to longer half lives. Therefore, prompt evacuation is the better solution. You would still need a Shelter even in these circumstances however, because panic on the street would prevent an immediate escape and sheltering in your Bunker will prevent you from getting contaminated more than you have to. Also, you won't know if there are going to be any other incidents, so staying put in your Shelter would be the right thing to do! 

As bullet proof vest protects from rounds of ammunition,  then mass between yourself and Radioactive fallout protect from radiation! As much mass as you can put between the walls of your Shelter the more protection you will have! It doesn't matter what the material is (be it: Earth, Lead, Concrete, Thick Magazines, etc) Any mass that absorbs half of the radiation is considered to have a Protection Factor of 2 (PF 2),compared to an unprotected person exposed on the surface with no protection or mass surrounding them!

Government recommended (absolute minimum) PF to aim for is PF 40! This means the mass between you and the radiation has reduced intensity to 1/40th  the dose you would have received exposed in the open! This would not really be enough in a nuclear exchange and would be particularly useless near Ground Zero! It is usually considered a joke by many experts! Yet by the illustration below, you can see achieving a PF of 300 - 400 is harder than you might think! 

(With 3.6 Inches of Soil the radiation is reduced by 1/2 (giving a PF 2). Pack 18 Inches of Soil over your Bunker and the PF is 32, with 30 Inches the PF is 300, and if you can stretch to 3 Feet of Soil overhead then the PF is 1000 (or in other words, radiation is 1/1000th its original intensity). 

Below is an illustration of differing amounts of Soil (in Inches) and their respective Protection Factors (PF) :-

Obviously, the more dense and the more thick the material, the more effective the Shielding! This is a given! Where it takes 3.6 Inches of Soil to cut the incoming radiation in 1/2 (doubling the PF), it only takes 2.4 Inches of Concrete to achieve the same result! Concrete has more density. Soil is cheaper and more abundant, but a little foresight and preparation can make all the difference. Concrete Shelters offer protection that Soil alone could never hope to achieve. Additionally  the 1/10th value thickness of relative materials is as follows:  Steel - 3.3 Inches, Concrete - 11 Inches, Soil - 16 Inches, Water - 24 Inches, Wood - 38 Inches! This all means that where you have these  materials in the dimensions stated, then the radiation passing through the Bunker is 1/10th the original intensity! Simple!!! That's why we are here at Bunker you can understand the intricacies of radiation sheltering without being left in any doubt!

In Summary:

A nuclear explosion will introduce itself to you with immense heat and light. The initial effects (prior to radiation) will be the blast pressure wave's and heat that can be as hot as the surface of the sun! This is where you remember (and enact) the drop, duck and cover (DDC) maneuver! This is to protect from rays of heat which will set you on fire and also protects from flying vehicles and the like...

The winds will be at hurricane strength up to 9 miles away. This will be upon you quicker than you think. Diving behind a solid wall could be a good idea (as long as the wall doesn't collapse on top of you). It would be better to find a hole in the ground or something. Here are some warhead sizes and detonation distances so you can gauge how long you have before the blast pressure waves reach you:

  • Five hundred Kilo Tons (KT), detonating at 2.2 miles out, will arrive in roughly 8 seconds and will endure 3 seconds.
  • A One Mega Ton (MT) warhead exploding (double the strength), at 5 miles out (double the distance), would arrive in roughly 20 seconds.     

If you have constructed a subsurface fallout shelter in your garden then the following Protection Factor's (PF) applies:

  •  30" (Inches) of soil = PF 300 (meaning the occupants would receive 1/300th of the radiation that the surface receives). 
  •  3' (Feet) of soil = PF 1000 (meaning the occupants would receive 1/1000th of the radiation that the surface receives).



           Organization Space of Bomb Shelter Population

It is recommended that you assign a bomb Shelter Manager (plus helpers). They will ensure the occupants of the shelter are broken down into manageable groups (called Shelter Units). This will especially be the case in a communal shelter! Doing this is essential because you have to discipline and control those who may panic, and keep a 'radiation exposure'  tally for everyone in the shelter. Each Shelter Unit will have a Unit Leader to liaise with Shelter Manager.

It may be impractical to have a Dosimeter on each individual's person, so the Unit Leader's will have to estimate the radiation exposure for every individual in their particular Unit. A radiation exposure tally has to be filled in by everyone in the Shelter. If anyone in the shelter cannot fill these in then the Leader's will have to ensure someone else does it for them (and accurately).

Once the shelter has been segregated into Shelter Units and Unit Leaders chosen, then everyone must know how to fill out the radiation exposure tally's. Ideally, these forms should be handed out before radiation arrives (so within 10 minutes maximum). The forms must have the right name on and filled in faithfully and truthfully. This is the Unit Leaders responsibility!

Radiation sensitivity categories

It may be necessary to separate people according to certain categories! Knowing which category to put people in (preferably before the radiation arrives) is helpful so you know which individuals require extra shielding. The effects of radiation on individuals varies according to whether you are: slim or fat (extra body mass helps), healthy or ill, young or old, and male or female!

Radiation Sensitivity Categories =

- Categories of individuals who may require extra shielding :-

  • The very old (thinner skin can be more prone to radiation damage)
  • Pregnant (carries risk of miscarriage), 
  • Babies (can grow up deformed),
  • Showing signs of radiation sickness,
  • Toddlers and young Children (more likely to suffer from radiation sickness),
  • People who have a cold or flu (these flu symptoms can mask symptoms of radiation sickness)

[As well as the initial risk of radiation sickness, the risk of complications arising after many years will always be there! Such complications include:

  • Various forms of Cancer's,
  • The Cancer you are most at risk from is  Leukemia,
  • Being unable to procreate (Sterility),
  • Eye Cataracts, and/or 
  • Injury to your DNA (Genetic Injury which you could easily pass on to any future Children). 

The above risks should not be on your mind to much when you are making decisions during a nuclear exchange or incident because it is possible to reduce the likely hood of these future effects taking place by keeping radiation exposure to a minimum at all times]. 

It is a general rule of thumb that the old, the infirm, the ill and the young are most at risk from radiation poisoning. Despite this being true though, it is a good idea for the Shelter Manager to treat everyone in the shelter as equal when it comes to radiation dangers, with exception to the very young and pregnant who need to be considered as requiring special protection and measures. Pregnant women should have their radiation exposure tally marked 'PG',  also on the next line write;  'Radiation: Sensitivity Category.”



          Space in your Bomb Shelter


So how do you ensure that the areas of highest protection in the shelter can fit everyone?

Well first you have to find those areas which offer the highest protection. Then the Shelter Manager should consider this problem seriously. He needs to consider 3 things: 

  1. The total number of people in the shelter
  2. How much space is there in the most secure areas of your shelter
  3. How long can the total number of people that can fit in this area stay there comfortably?

The Shelter Manager will know how many people are in the shelter, if he doesn't, then assign someone else as Shelter Manager because he isn't fit to lead! He should also by this time have collated the names of people who fall under the Radiation Sensitivity Categories, the number of Shelter Units (and their respective Leaders), and a record of any people who have any special technical skill that they can contribute with (IE, First Aid, Electronic Engineering, Doctors, Web Engineers, etc).  

The second question can be answered by having access to the interior schematics (or a rough drawing of the interior of the shelter) showing dimensions of the rooms (with lengths and breadth measured accurately and clearly). If you really don't know how to tell which parts of the shelter will offer the highest protection against radiation then the Shelter Manager will have to wait until the fallout reaches the shelter, then as the radiation inside increases he can measure each part of the shelter with his survey meter (Geiger Counter). Obviously,  its then just a matter of choosing the rooms with the lowest amount of radiation levels to house people under the Radiation Sensitivity Categories! After the radiation arrives for the first time it may be necessary for absolutely EVERYBODY to stay inside the rooms which offers the best protection from radiation. Once this initial radiation declines (after about 7 hours, the Initial Radiation has dissipated), healthy people can occupy rooms with higher levels of radiation. This, of course, is dependent upon enough space being available in the safer areas of the shelter. 

You can work out if there is enough space in the safer rooms by the following simple formula = 

  • Work out the Sq Ft area of the safer room/s
  • Divide by 10, (Sq Ft allowed per person for a short stay or stand).
  • If the number you arrive at is greater than number of people, then you have enough space in that particular room. 
  • If, however, that number is less than the number of people, then you will have to cram people in to the room/s.
You can cram people into the safer room/s by allocating 5 Sq Ft per person (instead of 10 Sq Ft per person).

When you cram people into the safer room/s, make sure that the room/s have plenty of fresh air and light. Otherwise you run the risk of people fainting, blind panic and Claustrophobia. 

The Shelter Manager will have to work all of this out within 10 minutes of the doors being shut!!!


           Bomb Shelter Entrance way Problems

Question: If a large number of people are entering the shelter WHILE radiation fallout is descending, whats the risk?

If people stop and cram themselves so that the shelter doors are blocked, then this is very problematic. If radiation fallout has started to descend then they may very well be covered in dust particles riddled with very energetic and lethal radiation! They may be dropping these dust particles inside the shelter (by trying to get shake them off), and they may have blocked the shelter entrance because they don't know which way they are going and are trying to get their bearings. 

It is therefore a good idea for the Shelter Manager to train and allocate someone to stand at the Bunker entrance way and direct people. These people should see to it that any radioactive dust is discarded (along with contaminated outer clothing) BEFORE coming into the Bunker.  

This allocated entrance person should also have a sealed large bucket or container (a lead container is perfect) where contaminated clothes can be safely stored. Those new arrivals should then be given concise directions. The entrance-way person is also responsible for clearing dust particles from entrance (and putting them in container), and if necessary, discarding radioactive dust outside (as long as the shelter entrance is covered so that fresh dust doesn't fall on him/her).

Entrance-way people MUST wear Dosimeters. These entrance-way people must also be listed as a 'Radiation Sensitive Category' (and be given special protection in safe room (the part of the shelter which offers higest protection from radiation). They should abandon their post when radiation levels read 10 R (rads) on their Dosimeter. If no-one else arrives, or looks likely to arrive, AFTER radioactive dust begins to descend then they should close the doors IMMEDIATELY! 

Entrance-way people therefore need to have the lead storage container ready, and also have brooms and dustpans available  Umbrellas are handy too!

Having directions on the walls of the entrance-way with arrows pointing to safest rooms will also help alleviate the pressure on the entrance-way person. If their ISN'T an entrance-way person then instructions on the walls giving instructions to new arrivals to discard their outer clothes and put them in the lead container, will be mandatory (have this anyway, even if you DO have an entrance-way person, as during the chaos some people may slip past him/her). 

Copyright: © Lee Holden, Director, Bunker Shield, 2013 AD. All rights reserved.

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