EMP Blast

EMP - High Altitude Electromagnetic Pulse

A nuclear detonation in the upper atmosphere creates an electromagnetic pulse (EMP), a powerful, damaging electromagnetic field covering a subcontinent-scale region. 

It is important to note that, due to the statistical nature of field characteristics, most conventional computers and low voltage electronics will likely be unaffected and available to be reenergized if power grid operation can be restored – a key factor in enabling cost effective power grid protection strategies – and in preserving the viability of most of the customer “load” that will also be essential to such strategies. 

The size of the affected region depends on burst height, and certain features of the warhead.

Based on the full range of U.S. and international government studies and laboratory hardware vulnerability tests, and on U.S. and Russian nuclear testing, an EMP strike on an unprotected power grid, especially given its large, multi-region footprint, would cause an extended duration, subcontinent-scale duration power outage, and would precipitate cascading, direct and indirect failures of all other critical societal infrastructures.

EMP has been studied and addressed diligently as a military threat for over 50 years.  In the United States, EMP has been treated by DOD as an active, growing hazard for decades. In 2011 the U.S. Defense Science Board renewed and highlighted this policy, issuing an interim report citing progress, coupled with ongoing recommendations for EMP survivability of certain DOD assets.  In 2015, DOD expanded these recommendations to mandate EMP protection of “all mission critical facilities,” and announced its plans to reopen, upgrade and reoccupy the Cheyenne Mountain military complex due to its intrinsic EMP-protected characteristics.

The Congressional EMP Commission noted that deterring attack from terrorists who acquire nuclear weapons would be especially difficult because “such groups have no state identity, have only one or a few weapons, and are motivated to attack the US without regard for their own safety.”

The United States and its partners abroad conduct a variety of programs to reduce the likelihood that terrorist groups can acquire the nuclear materials and other components necessary for building such weapons. The Cooperative Threat Reduction (CTR) program, for example, helps secure nuclear materials in the former Soviet Union.  While these programs have demonstrated substantial progress in reducing the threat that nuclear materials will be stolen, current
estimates assess that, as of January 2012, there were still approximately 1440 tons of highly enriched uranium and around 500 tons of separated plutonium stockpiled globally -- providing a vast array of potential targets for terrorists seeking such materials.  Other concerns include increasing proliferation of “nuclear weapon precursor” technology, and security concerns associated with the growing stockpiles of nuclear warheads and missiles in the control of unstable or unfriendly nations.