Behind the 2016 NTI Index

Does the NTI Index address nuclear safety? What is the difference between nuclear safety and nuclear security?
Although both are important, the NTI Index assesses security, not nuclear safety. Nuclear security involves the range of actions to track, protect and manage weapons-usable nuclear materials, whether they are in use, in transport or in storage, to prevent their theft or illicit acquisition, and to protect nuclear materials and nuclear facilities from acts of sabotage. The goal of nuclear safety is to protect public health and minimize potential harmful effects of nuclear activities on people or the environment, such as by ensuring safe reactor operations to prevent an accident.

Why does the NTI Index have multiple rankings and how are they different?
The “theft ranking” refers to the two sets of data that assess the nuclear materials security conditions of 24 countries with one kilogram or more of weapons-usable nuclear materials and 152 countries with less than one kilogram of or no weapons-usable nuclear materials with respect to the risk of theft of those materials. This theft ranking was included in both the 2012 and 2014 editions of the NTI Index.

The 2016 NTI Index also includes a new “sabotage ranking,” that assesses nuclear security conditions of 45 countries with nuclear facilities, the sabotage of which could result in a significant radiological release causing serious off-site health consequences.

Theft Ranking

What materials are included in the NTI Index theft ranking and what materials are not included?
The theft ranking covers highly enriched uranium (HEU), separated plutonium, and the plutonium content in fresh mixed oxide (MOX) fuel. The theft ranking does not assess security for low-enriched uranium or the radiological materials needed to build a “dirty bomb.” 

Why does the theft ranking use 1kg of weapons-usable nuclear materials as its threshold?
The threshold of one kilogram takes into account the International Atomic Energy Agency (IAEA) guidelines (INFCIRC 225, Rev. 5), which state that quantities greater than one kilogram of HEU should be afforded higher levels of protection.

Why are countries with less than one kilogram or no weapons-usable nuclear materials included in the Index?
Countries with little to no weapons-usable nuclear materials are included because they also have a responsibility not to become safe havens, staging grounds, or transit points for illicit nuclear activities.

How is the 2016 Index different from the 2014 edition?
After the launch of the 2014 NTI Index, NTI and the EIU sought feedback from experts, practitioners and officials on the index framework and overall approach.  Working with the International Panel of Experts, adjustments were made to the 2014 edition.  For example:

  • The 2016 NTI Index includes a new indicator to assess measures to protect nuclear facilities from cyber attacks.
  • Minor edits were made to three subindicators—law enforcement response training, peer review, and UNSCR 1540 implementation.

To allow direct comparison between 2012, 2014, and 2016, the EIU rescored countries for 2012 and 2014; the comparisons in the 2016 report reflect the new scoring.

Why were the scores re-calculated?
The changes made prevent an “apples to apples” comparison between the 2016 list and earlier versions. To ensure an accurate year-on-year comparison, the EIU rescored countries for previous years, and the comparisons in the 2016 report reflect that new scoring. Full details on this process are available in the full EIU Methodology at

Did any countries move from the Index of countries with materials to the Index of countries without materials?
Uzbekistan was included in the 2014 NTI Index list of countries with materials but cleaned out their inventory of weapons-usable nuclear materials in 2015. It is now included on the list of 152 countries without weapons-usable nuclear materials.

Sabotage Ranking

Are all countries with nuclear reactors included in the sabotage ranking?
No. The scope of the sabotage ranking includes only certain nuclear facilities, the sabotage of which could result in a significant radiological release causing serious off-site health consequences. Based on consultations with the International Panel of Experts, members of nuclear industry, and other technical advisers, NTI determined that only these types of nuclear facilities would lead to this set of consequences:

  • Operating nuclear power reactors or nuclear reactors that have been shut down in the last five years
  • Research reactors with a capacity of two megawatts or greater
  • Reprocessing facilities
  • Spent fuel pools, only if the fuel has been discharged in the last five years and if not associated with an operating reactor.

There are 45 countries with one or more of these facilities, and all are included in the sabotage ranking.

Are all 45 of the countries in the sabotage ranking included in the theft ranking?
Yes. 22 of the 45 countries are in the theft ranking for countries with one kilogram or more of weapons-usable nuclear materials, and the remaining 23 are in the theft ranking for countries with less than one kilogram of or no weapons-usable nuclear materials.

Are all countries with weapons-usable material included in both the theft ranking and the sabotage ranking? 
No. Two countries with weapons-usable materials that are in the theft ranking are not in the sabotage ranking. Belarus and Italy each have more than one kilogram of weapons-usable nuclear materials, but those materials are in a type of storage where an act of sabotage against them would be unlikely to cause a significant radiological release. Although those materials are still vulnerable to theft and, if stolen, could be used to build a nuclear bomb, an attack on those facilities would not pose a major radiological hazard.

About the Process

How were the 176 countries selected?  Why are some countries missing?
The number of countries in the NTI Index was determined by the scope of the Economist Intelligence Unit’s Risk Briefing service, which includes almost all countries in the world. All countries with one kilogram or more of weapons-usable nuclear materials are included in the NTI Index.  Of the remaining 169 United Nations member states, 152 are included in the Index due to EIU’s capacity to collect data in these countries.

What data sources were used for the Index?
To score the indicators for the 2016 NTI Index theft ranking, the EIU used a wide range of trusted international and national sources. International sources included the United Nations (UN), the International Atomic Energy Agency (IAEA), as well as academic and technical studies and EIU resources and databases, including reports compiled through EIU’s Risk Briefing service. National sources included legal and regulatory documents and national reports regarding nuclear materials security. In addition, 25 of the 47 countries in the theft ranking, the sabotage ranking, or both reviewed the data.

Which countries received briefings? How were governments involved in the process?
All countries in the theft ranking for countries with materials and/or the sabotage ranking (47 in all) were offered the opportunity to be briefed in-person by NTI staff on the purpose, goals, and approach of the 2016 NTI Nuclear Security Index. Thirty-six of those countries were briefed in-person or by conference call. In addition, all 47 states were asked to review and confirm preliminary data gathered by the EIU, and 25 states reviewed the data. The purpose of the data review and confirmation process was to ensure the most accurate and up-to-date information possible, given that much of the research involved subjects for which information is not always publicly available. The research team recognized that some countries might be willing, upon request, to provide the EIU with more detailed information than is readily available to the public.   

How did you select the international panel members?
NTI selected the members of the International Panel of Experts for their subject-matter expertise, as well as representation from nuclear- and non–nuclear-weapon states, from countries with and without materials, and from developed and developing nations.  For 2016, NTI added a new U.S. panel member from nuclear industry.

Did the international panel agree with NTI’s findings and recommendations?
The international panel assisted NTI and the EIU in developing the NTI Index framework and selecting indicators and determining their relative priority. The policy recommendations, however, were developed by NTI. Panel members did not score individual countries. They did not represent their country’s interests as part of the process, and they acted in their personal, not professional, capacities.

What is the difference between the Excel version of the NTI Index and the website?
The website offers all top-line data as well as NTI observations and recommendations. The Excel model, which can be downloaded from the website, offers greater ability to examine the data and correlations, compare regions, and analyze data to the sub-indicator level. The Excel version also allows the user to modify weights and subindicator scores to see how changes impact overall results.

Do I need Excel to use the Index after I’ve downloaded it?
The model is designed with Excel software. It may open in other programs but may not be fully functional.

Are the earlier reports still available?
Yes, in the Archives.

Nuclear Materials, the Threat and the Response

What’s the difference between highly enriched uranium, plutonium, mixed oxide fuel and low enriched uranium?
HEU refers to uranium with a 20 percent or higher concentration of the isotope U-235 and is most commonly produced through centrifuge enrichment. Uranium enriched to 20 percent or above is weapons-usable, although 90 percent enrichment or higher is considered optimal for nuclear weapons.  Plutonium, on the other hand, is made by irradiating uranium in a nuclear reactor.  Greater quantities of HEU than plutonium are needed to make a bomb. Mixed oxide fuel, or MOX, is a blend of plutonium and HEU, and is used in light water reactors for energy generation. For additional information about HEU, plutonium and MOX fuel, see Understanding Nuclear Materials.

How much HEU and plutonium does it take to build a nuclear weapon?
According to the IAEA’s definition of a “significant quantity” of nuclear material, 25 kg of weapons-grade HEU or 8 kg of plutonium are the approximate quantities at which the manufacture of a nuclear explosive device cannot be excluded.

Is the threat still urgent?  Terrorists haven’t used a nuclear weapon yet.
Terrorists have expressed the desire to acquire and use weapons of mass destruction and the know-how is available. Terrorist organizations have proven to be patient and methodical: the 9/11 Commission reported that training for the 2001 attacks began more than a decade earlier. What’s more, over a hundred incidents of theft and other unauthorized activities involving nuclear and radioactive material are reported to the International Atomic Energy Agency each year. The threat is urgent because the consequences of a nuclear terrorist attack would be catastrophic.

How difficult would it be for a terrorist group to build and detonate a bomb?
The most difficult hurdle to building a bomb is acquiring sufficient quantities of weapons-usable nuclear material. The know-how is available and if terrorists were able to buy or steal enough material for a weapon, a well-organized group could likely gain or hire the expertise needed to build an elementary nuclear weapon.

Isn’t this Index a roadmap for terrorists, directing them to countries that may have accessible material or vulnerable facilities?
No. The NTI Index assesses the broad nuclear security conditions within a country at a national level and is not an on-the-ground evaluation of specific security measures in place at the facility level. Such specific details are typically kept secret, as they should be.

Doesn’t the IAEA oversee all nuclear materials already? Don’t they keep some kind of index?
Although the IAEA is the closest thing the world has to a global nuclear watchdog, it does not have the authority or resources to develop a comprehensive picture of the status of weapons-usable nuclear materials around the world or to ensure the security of nuclear materials.  Through its safeguards system, the IAEA has a crucial role in verifying that nuclear materials are not diverted by states from peaceful use to nuclear weapons. However, IAEA safeguards are not designed to prevent theft of nuclear materials and apply only to civilian materials. 

Which international treaties and regimes are most important to nuclear materials security?
There are a number of treaties that are important for nuclear materials security, including the Convention on the Physical Protection of Nuclear Material (CPPNM), its 2005 Amendment, and the International Convention for the Suppression of Acts of Nuclear Terrorism (ICSANT).

Unfortunately, the CPPNM and ICSANT are not universal and the 2005 Amendment to the CPPNM in not yet in force. That the 2005 Amendment to the CPPNM is not yet entered into force leaves a particularly large gap in the international system for securing nuclear materials, as the CPPNM in its original form requires only physical protection measures for nuclear materials in international transit. The 2005 Amendment requires physical protection measures for nuclear material in use, in storage and during domestic or international transit, as well as for nuclear facilities. Entry into force of the 2005 Amendment to the CPPNM is one of the key goals of the Nuclear Security Summit process.

The nuclear terrorism convention (ICSANT) commits states to criminalize acts of nuclear terrorism (including possession of unlawful materials and damage to nuclear facilities) and promotes information sharing and cooperation among countries on investigations and extraditions. These treaties are included in the Global Norms category of the NTI Index, along with other voluntary agreements and commitments important to nuclear materials security.

How many countries have nuclear weapons?
Nine countries currently possess nuclear weapons: the United States, Russia, the United Kingdom, China, France, India, Pakistan, Israel, and North Korea. 

What is WINS?
The World Institute for Nuclear Security is a Vienna-based organization that brings together practitioners—nuclear security experts, nuclear industry leaders, governments, and international organizations—to provide an international forum for those accountable for nuclear security to share and promote the best security practices available to secure vulnerable materials from theft. NTI helped found WINS in 2008.