Mighty Derringer: U.S. Nuclear Terrorism Exercise Leaves Indianapolis in Ruins

June 1st, 2012

Fictional Scenario Results in Nuclear Destruction of Large Part of City: 1980s Secret Exercise Judged Positively But Underscores Range of Potential Problems – Bomb Detection, Interagency Coordination, Containment of Contamination, General Confusion – Published on The National Security Archive, Electronic Briefing Book No. 380, by Jeffrey T. Richelson and William Burr, May 29, 2012. 

Washington, D.C., May 29, 2012 – A secret exercise in 1986 by a U.S. government counter-terrorist unit uncovered a host of potential problems associated with disrupting a nuclear terrorist plot in the United States. Declassified documents released under the Freedom of Information Act (FOIA) and posted today by the National Security Archive offer the first detailed public look at the inner workings of the agencies, military units and other U.S. entities responsible for protecting the country from a terrorist nuclear attack … //


In late January and early February 2012, members of the Department of Energy’s Nuclear Emergency Support Team (NEST) patrolled Lucas Oil Stadium as well as surrounding areas of Indianapolis as a precautionary measure in advance of Super Bowl XLVI. An initial survey to gather information on background levels of radiation was followed by an actual search for signatures associated with either a nuclear explosive device or a radiation dispersal device (a ‘dirty bomb’).1 Fortunately, none was found.

Over twenty-five years earlier, for a few days in early December 1986, NEST personnel also patrolled Indianapolis, also in search of a nuclear device. That search was triggered by an intelligence report that suggested that an Improvised Nuclear Device (IND) might have been smuggled into the city by terrorists. With the assistance of the Delta Force, U.S. personnel were able to recover and disable the device in a fictitious neighboring country; unfortunately the Indianapolis device exploded and 20 square blocks in downtown Indianapolis were completely destroyed.

As it happens, the terrorist group, the intelligence report, and the detonation were fictional – elements of a NEST exercise designated MIGHTY DERRINGER, one of a number of tests designed to anticipate and prevent the potential real-world catastrophe of a terrorist nuclear strike in a major American city. Documents published today by the National Security Archive provide newly declassified details on how the MIGHTY DERRINGER exercise unfolded and how the participants later evaluated it.

This is the most extensive set of declassified documents on any nuclear counterterrorism exercise, covering every phase of the response, from concept to critiques, and it offers valuable insights into a world that is usually hidden from public scrutiny. Among the disclosures:

  • § The role of the top secret Joint Special Operations Command’s Delta Force in carrying out the assault on the terrorist cell in the fictional country of Montrev.
  • § Descriptions of the different types of disablement techniques U.S. forces utilize – emergency destruct, standard destruction, and hard entry.
  • § Assessments of the coordination problems and different perspectives of agencies that would be involved in a real-world response.

The instruction to establish NEST, known until 2002 as the Nuclear Emergency Search Team, took the form of a November 18, 1974 memo from Maj. Gen. Ernest Graves, the Atomic Energy Commission’s assistant general manager for military application, to Mahlon Gates, the manager of the commission’s Nevada Operations Office. (Document 1). Gates was “directed and authorized” to assume responsibility for the planning and execution of field operations employing AEC radiation detection systems for the “search and identification of lost or stolen nuclear weapons and special nuclear materials, bomb threats, and radiation dispersal threats” …

(full text, Documents 1 to 69, (including The Exercise and Critiques), Abreviations, Notes 1 to 4).

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