Security: nuclear materials

Scoring security

20 April 2012

A new index, published in January, ranks the security of weapons-usable nuclear material in over 170 countries.

Weapons-usable nuclear material including highly enriched uranium (that is, uranium enriched to 20% or more in uranium-235), separated plutonium, and plutonium contained in mixed-oxide fuel is stored at hundreds of sites across the globe. Some of those sites are well-secured, but many are not, leaving weapons-usable nuclear materials vulnerable to theft or sale on the black market.

A new index released in January ranks nuclear material security in 176 countries, 32 with at least one kilogram of weapons-usable nuclear material and 144 with less than one kilogram. It aims to spark international discussion about the priorities required to strengthen security and, more importantly, to encourage governments to take action to reduce risks.

“I want to be clear that the index is not about congratulating some and chastising others. Instead, it should be used as a tool for initiating discussion, analysis and debate,” said Sam Nunn, former US senator and chief executive officer of the Nuclear Threat Initiative (NTI). This international non-profit organization aims to increase global security by reducing the risk of use and preventing the spread of nuclear, biological and chemical weapons. NTI worked with the Economist Intelligence Unit (EIU) and an international panel of experts and technical advisors to develop the index. The project was funded by NTI with support of US charitable organizations the Peter G. Peterson Foundation, the John D. and Catherine T. MacArthur Foundation and the Carnegie Corporation of New York.

The Nuclear Materials Security Index uses five categories comprising 18 indicators to assess the nuclear materials security conditions (see Figure 1). The 32 states with more than 1 kilogram of weapons-usable nuclear material were evaluated across all five categories:

Figure 1: The NTI index's five indicators
Figure 1: The NTI index uses five indicators to assess nuclear materials security conditions, although fewer are used for countries with no weapons-useable material. The indicators are: 1. quantities and sites, 2. security and control, 3. global norms, 4. domestic commitments and capacity, 5. Societal factors.

Quantities & sites. This category examines the total amount of weapons-usable nuclear materials and the number of facilities within a state on the premise that the potential for theft increases with higher quantities of materials, more sites where materials are located, and more frequent transport of materials. Over time, actions that decrease quantities of materials and numbers of sites will reduce risks.

Security & control measures. This category assesses five specific measures: physical protection, control and accounting procedures, personnel and security infrastructure, security related to materials in transport, and emergency response. Because detailed information about site security and other physical protection measures are not—and should not be—publicly available, the EIU reviewed a state’s legal and regulatory system as an alternative way to assess its commitment to these measures. This approach is based on the assumption that if states have stringent legal mechanisms in place, they are more likely to have robust physical security, accounting systems, and personnel reliability measures as well. For some states (Israel, Iran, Pakistan, and North Korea), even this proxy data was not available. In those cases, because the military has a major role in securing such states’ weapons-usable nuclear materials stocks, a separate proxy based on estimates of the military’s capabilities was used.

Global Norms. This category examines the extent to which states participate in international legal agreements, take on voluntary commitments to materials security, and provide transparency about inventories and security measures. Two international legal agreements were deemed especially important for assessing a state’s commitment to nuclear materials security: (a) the Convention on the Physical Protection of Nuclear Material (CPPNM), along with a 2005 amendment to that convention, and (b) the International Convention for the Suppression of Acts of Nuclear Terrorism (ICSANT). Participation in voluntary initiatives or financial or other security-related assistance to other countries or international organizations was also assessed. Because appropriate transparency can contribute to international confidence in a state’s materials security practices, countries with weapons-usable nuclear materials were evaluated for whether they report their quantities of materials, publish broad outlines of materials security arrangements, and invite security reviews.

Domestic commitments & capacity. This category evaluates how well a state discharges international obligations to which it has committed. In particular, it assesses the domestic implementation of two international accords. They are United Nations Security Council Resolution 1540 (which imposes binding obligations on states to establish domestic controls to prevent the proliferation of nuclear, chemical and biological weapons, and their means of delivery), and the IAEA convention on the Physical Protection of Nuclear Material (CPPNM). It also examines the presence of and adherence to International Atomic Energy Agency (IAEA) safeguards agreements and looks at whether a state has an independent regulatory agency responsible for nuclear security.

Societal factors. This category examines underlying conditions that contribute to or detract from the confidence of the international community concerning the risk of nuclear theft within a state. Indicators include levels of corruption, prospects for political instability over the next two years, and the presence of groups interested in and capable of illicitly acquiring nuclear materials. The indicators addressing corruption and political stability are based on the EIU’s existing data.

Within the five broad categories, 18 indicators and 51 sub-indicators were evaluated, some of which were weighted more heavily than others. Figure 2 shows the weights assigned to the categories for states with weapons-usable nuclear material. The weights were assigned according to input from an international panel of experts including representatives from the World Institute for Nuclear Security (which is supported by NTI) and a former IAEA official.

Figure 2: Relative indicator weighting for countries with weapons-useable material
Figure 2: Relative indicator weighting for countries with weapons-useable material

Countries without weapons-usable nuclear materials were evaluated across three of the five categories: global norms (40%), domestic commitments and capacity (40%), and societal factors (20%).


The table below gives the overall rankings for the 32 countries with more than one kilogram of nuclear weapons-usable material.

NTI rankings for 32 countries with more than 1kg of nuclear weapons-useable material
NTI rankings for 32 countries with more than 1kg of nuclear weapons-useable material

The figure of one-kilogram threshold was chosen for several reasons, NTI says. Critics at India’s Institute for Defence Studies and Analysis (IDSA) argue that this amount is insufficient to make a ‘credible’ weapon, which would require a minimum of 5 kg of plutonium or 25 kg of highly enriched uranium (see also box). In explanation of the one-kilogram threshold, NTI said it believes that even small quantities of weapons-usable nuclear materials warrant stringent protection and every kilogram of nuclear materials that a non-state actor might be able to obtain could contribute to the illicit construction of a nuclear weapon. NTI says its selection of the one-kilogram threshold was not arbitrary but rather a considered decision based on IAEA guidelines. INFCIRC 225/Rev 5 recommends that quantities greater than 1 kg of HEU should be used or stored only within an area protected by additional security measures.

Australia ranks first in the table for two key reasons: first, it maintains only a small amount of weapons-usable nuclear materials; and second it scores well across all other categories.

The shading in the table indicates the typical ranking within each of the five categories. Note that most of the nuclear-armed states (United Kingdom, United States, France, Russia, Israel, China, India, Pakistan and North Korea) rank low in the quantities and sites category, as indicated by the lighter shading. This is typically because they have a large inventory of weapons-usable material held at numerous sites. The UK, which ranks lowest overall in this category, would have moved up to fourth position overall if the quantities & sites indicator had not been included in the index. Similarly the United States would move up to second overall if the quantities of materials and number of sites were not counted in the index. The United States could also improve its position in the table by ratifying relevant international agreements.

Dounreay site
The UK government is proposing to move unirradiated plutonium and high-enriched uranium-bearing fuels from secure storage at Dounreay in Scotland to Sellafield in Cumbria. Image courtesy DSRL Ltd and NDA

The report highlights the fact that Russia has made tremendous progress in securing its weapons-usable nuclear materials and that it ranks above average in its effort to secure its materials and its support of global norms. It ranks 24th overall because of its quantities of nuclear materials, large number of sites (which could be further consolidated), and the need for stronger regulations regarding the physical security of materials while in transit.

France could also better its ranking (currently 19th) by ratification of international agreements, reducing quantities, and consolidation of sites with weapons-usable nuclear materials.

Nearly a quarter of the states with weapons-usable nuclear materials scored poorly on societal factors because of very high levels of corruption. Of those countries, several also scored poorly on the prospect of political instability over the next two years. The combination of those factors significantly increases the risk that nuclear materials might be stolen, with help from corrupt insiders or in the midst of government distraction or political chaos.

Many of the low-scoring nuclear-armed states are beset by societal factors that undermine international confidence in the application and enforcement of their nuclear materials security measures.

Weapons-usable materials stocks are still increasing in four states in particular: in India and Pakistan, which use those stocks for weapons, and in the United Kingdom and Japan, which reprocess plutonium for use in civilian power reactors. In addition to those four countries, some other states, such as France, continue to produce weapons-usable nuclear materials, but because of the use of plutonium as fuel in civil power reactors, their overall material inventories are currently static.

What next?

“Countries participating in the Nuclear Security Summit in Seoul [26-7 March] can use the index to stimulate discussion and define future commitments,” said Page Stoutland, NTI vice president, nuclear materials security programme, and index co-leader.

States have yet to reach a consensus on what steps matter most when it comes to securing vulnerable weapons-usable nuclear materials. Today, there is no common international system for regulating how weapons-usable nuclear materials are produced, tracked, protected, and controlled, and there is no way to measure the actions states are taking to build assurance and accountability around nuclear materials security. There is also no global institution or authority with the mandate to help create and monitor such a comprehensive security system.

According to NTI, 14 of the 32 states with weapons-usable nuclear materials in the NTI index have less than 100 kg of the material, and many of these may be good candidates to eliminate them over the next few years. Many of these countries have only small amounts of materials (which might be converted to non-weapons-usable fuels) at one or two sites (which might be shut down). During the past two decades, 19 countries plus Taiwan have set an important example by eliminating their stocks of weapons-usable nuclear materials.

Author Info:

This article was originally published in the March 2012 issue of Nuclear Engineering International magazine.

See it your way

Viyyanna Sastry and Rajiv Nayan of India’s Institute for Defence Studies and Analysis (IDSA) have criticized the NTI index in an online comment (
NTI, which says it welcomes debate about its listing, has responded with an extended rebuttal (
One of Sastry and Nayan’s criticisms was about the inverse relationship between the number of sites and the country’s security rating. It points out that the first ten rankings in the NTI index are awarded to smaller countries with smaller sites and quantities.
In a short letter to NEI, Nayan said:
“The proposition that the larger amount of nuclear materials will automatically cause nuclear insecurity is flawed. A few countries may have some problems, but it does not mean all the countries that generate a higher percentage of electricity, naturally with larger amounts [of nuclear material] will or should face security problems. This sweeping generalization basically ignores security preparedness of a country.”
In its rebuttal, NTI noted that an exploratory zeroing out India’s indicators for material quantities and number of sites only improved India’s rank by one position, from 28th to 27th overall.
A spokeswoman also told NEI that there is no correlation in the index between amounts of materials and overall score. Although the top five scorers have small quantities of materials, the Netherlands, which scored sixth, is estimated to have up to 2 tons of materials. Also, the bottom five scorers are countries with materials holdings ranging from a few kilograms up to several tons of materials.
But readers do not need to take NTI’s word for it. NTI has presented the high-level results of the index in an easily-accessible format on its website In particular, readers can modify the relative weighting of each factor and see its effect on the list momentarily. A downloadable version of the NTI Index is also available through the website, with complete results and data and extended interactive features in a Microsoft Excel spreadsheet format.

FilesNTI ranking table
Figure 1

Figure 2: Relative indicator weighting for countries with weapons-useable material Figure 2: Relative indicator weighting for countries with weapons-useable material
Figure 1: The NTI index's five indicators Figure 1: The NTI index's five indicators
NTI rankings for 32 countries with more than 1kg of nuclear weapons-useable material NTI rankings for 32 countries with more than 1kg of nuclear weapons-useable material
Dounreay site Dounreay site
Figure 1 Figure 1
NTI ranking table NTI ranking table

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