So, You Think You Are Safe?

So, you purchase an underground shelter which has a nuclear-biological-chemical air filtration system and you feel safe from the weapons effects from a nuclear weapon. The real-world problem is that virtually all of the underground shelters on the market today are Survival Shelters, and are not in fact Nuclear Shelters. A nuclear shelter has a Radiation Design Dose establishing what level of radiation the shelter is designed to operate in and what radiation doses can be expected inside the shelter. Survival shelters have no published radiation design dose of any kind. The radiation shielding from overhead or through the entranceway is unknown in a survival shelter. This is why survival shelter manufacturers do not publish the distance from ground zero the shelter is designed to operate in.

Weapons Effects Tables

The government and university expert committee working with engineer Walton McCarthy on the Principles of Protection book created Weapons Effects tables that show the overpressure and radiation doses for various size nuclear weapons at any given distance from ground zero.[i] This data is then used in proper shelter engineering to determine how much radiation shielding is required to protect people inside the shelter.

Military Survival Shelters?

Many survival shelter companies even go so far as to advertise that they sell to the military. The military is not allowed to purchase survival shelters or any product without performance data, including the radiation design dose of the shelter, internal radiation doses, TRS Rating, EMP MIL-188-125 confirmation, etc.

Overpressure, Blast and Radiation Dangers

At any given distance from ground zero, there is a level of overpressure in pounds per square inch (psi) and a level of radiation (rems). These are well-established from actual above ground nuclear weapons tests. For a 100 KT surface burst the pressure drops to zero at 2.1 miles from ground zero. But the radiation dose is still 6,500 rems. That same weapon at 0.3 miles from the shelter will impose a 100-psi overpressure load onto the shelter surface and expose it to over a million rems of neutron and gamma radiation.

What Protects You?

Many survival shelter manufacturers claim that their shelters are completely safe. What they are not telling you is that you are safe in their shelters so long as you are at least 100 miles away from ground zero. At this distance, there is no overpressure and very little fallout radiation. It is, in fact, the distance from ground zero, and not the shelter, that is protecting you from radiation.

Approximately 200 rems of radiation exposure creates a 50% chance of death. Seatbelts are required starting at 40 psi. For shelter occupants to survive a 100 KT surface burst 2.1 miles away, the shelter must protect occupants from 6,500 rems but no overpressure. At 0.3 miles, it must protect the occupants from just over a million rems and 100 psi overpressure.

The 100-mile, 2.1 mile and the 0.3 mile distances from ground zero create very different environments for a fallout shelter. Some shelter manufactures claim a 100-psi shelter rating but claim nothing about their shelter’s ability to protect occupants from radiation and ground shock at that pressure level. The shelter might survive 100-psi of overpressure but at this pressure or distance from ground zero, the shelterists will almost certainly die of lethal radiation. It makes little sense to survive a nuclear blast but die inside the shelter from a lethal dose of radiation. For this reason, the radiation levels must be published in relation to the level of overpressure. Further, a 100-psi shelter will not necessarily stop the ground shock from creating projectiles out of the people inside the shelter. In other words, a 100-psi shelter will survive, but it will not protect the people inside from becoming projectiles even if they are wearing seatbelts.

The Nuclear Shelter Radiation Design Dose

The very first step in designing a nuclear shelter is to establish the radiation design dose. There are two established types of radiation design doses: Overhead and Entranceway. The level of outside radiation is based on 1) the size of the nuclear weapon. 2) the type of burst such as ground burst, surface burst, or air burst, and 3) overpressure of the weapon which is always directly tied to the level of radiation (both neutron and gamma) at various distances from ground zero. Each of these inputs determines the design considerations for the Overhead and Entranceway radiation protection.

Total Rems in Shelter

Principles of Protection: The U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Design Standards, 6th edition, 2013, Brown Books publishes the nuclear weapons effects that set standards for overpressure and radiation exposure.

This book establishes the Total Rems in Shelter or TRS which is a two-number radiation exposure system. A TRS of 5-10 indicates that the shelterists will receive a maximum of 5 rems from the overhead and entranceway at the 10-psi distance from a given size surface burst weapon which is usually based on a 100 KT surface burst.

“Survial Shelter” vs. “Nuclear Shelter”

Only real nuclear shelters will have a TRS rating. The maximum radiation dose by this standard is 25 rems from all sources for both gamma and neutron radiation at a given overpressure rating or distance from ground zero during the first 30-day period. Past actual nuclear weapons test show that 99.99% of the total lifetime radiation dose will be delivered during the first 30 days. Most of the radiation that enters underground shelters comes through the entranceway. Incredibly, many survival shelter companies put two entranceways on the shelter so the radiation dose is doubled.

Electromagnetic Pulse (EMP) Shielding

All nuclear weapon burst types (surface, air, high altitude) produce an Electromagnetic Pulse that fries anything with a computer chip and can produce power grid outages. Virtually all underground shelters will provide some EMP shielding. However, any shelter that does not meet MIL-188-125 (MIL-188-125 High-Altitude Electromagnetic Pulse (Hemp) Protection for Ground-Based C4I Facilities Performing Critical, Time-Urgent Missions) shielding leaves electronics, computers and communications equipment vulnerable to EMP damaging frequencies.

MIL-188-125 is an EMP Shielding military standard used all over the world. The decibel (dB) scale is used to reflect the logarithmic progression of shielding efficiencies, and is not related to sound. Military compliance to this standard is usually met using specific individual aluminum enclosures, not Faraday Cages, for all MEE (Military Essential Equipment) communications and electronics equipment. If an underground shelter is not shielded to this MIL-188-125, it is not EMP shielded.

The term “EMP Shielded” is an ambiguous term and is very misunderstood especially in the underground shelter industry. A shelter said to be EMP Shielded but that is not shielded to MIL-188-125 specifications will not protect electronics inside the shelter from an EMP event. The “EMP Shielding” claim does not necessarily mean that the shelter is EMP shielded for all EMP frequencies at the minimum required decibel (dB) levels to provide protection to the electronic Mission Essential Equipment (MEE).

FEMA Shelter Standards

The general public relies on FEMA to check that shelter standards are adhered to. However, FEMA does not certify or approve underground shelters. FEMA only publishes tornado shelter guidelines. They do not publish or suggest any Nuclear-Biological-Chemical (NBC) warfare shelter guidelines or standards. A shelter manufacturer may claim that its shelter meets or even exceeds FEMA tornado shelter guidelines. But there are no FEMA NBC shelter guidelines, and there are no FEMA shelter certifications or approvals since FEMA is not a certifying agency. Underground shelter manufacturers can claim anything with no data to support their deceptive protection claims and that is exactly what is happening. Shelter manufacturers are unchecked.

The Principles of Protection

There has only been one book in the past 40 years to address a set of standards for underground shelters. It was written by Walton McCarthy with help of a committee of government, university and industry experts and has been on the market for 20 years. Principles of Protection: The U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Design Standards, 6th edition, 2013, Brown Books, defines scores of engineering standards for proper shelter design protection from nuclear blast, radiation, biochemical threats and EMP. This book has a weapon effects table from actual nuclear weapons tests (insert link here) developed by committee of experts. The nuclear shelter engineering book’s committee included experts from the US Department of Energy, US Department of Defense, Strategic Applications International, Nuclear Engineering Laboratory from the University of Illinois, Oak Ridge National Laboratories, Chemical Division of Edgewood Arsenal, Brookhaven National Laboratory, US Defense Nuclear Agency and the US National Bureau of Standards.

Principles of Protection is available on Mr. McCarthy has designed, engineered, manufactured and installed more than 1,400 shelters since 1977. More details on Walton McCarthy can be found on Mr. McCarthy is presently the principle engineer for NORAD Shelter Systems LLC.

[i] Principles of Protection: The U.S. Handbook of NBC Weapon Fundamentals and Shelter Engineering Design Standards, 6th edition, 2013, Brown Books, Weapon Effects Tables Appendix A.