Illicit Trafficking of Weapons-Usable Nuclear Material:

Facts and Uncertainties

Lyudmila Zaitseva and Friedrich Steinhausler

First published by the
F O R U M  O N  P H Y S I C S  &  S O C I E T Y

of The American Physical Society 
January 2004

1.           The danger of perceived vs. actual threats

In the recent past the issue of covert trade in nuclear material gained public prominence when it was erroneously claimed by British intelligence sources that the former Government of Iraq under Saddam Hussein had tried to obtain uranium from Niger. The far reaching consequences of such assessments for society were clearly demonstrated by US President George W. Bush in his speech on January 28, 2003, using this incorrect information as one of the reasons why terrorists and countries belonging to the “Axis of Evil” posed a potential nuclear threat.

[i] In view of the occurrence of such significant errors even in the intelligence community, it is not surprising that information in the media on the topic of illicit trafficking of nuclear material is frequently flawed by errors. Examples of such errors include failure to differentiate nuclear weapons-usable material[ii] from other radioactive material, incorrect use of physical units of activity and dose rate, and misquotation of isotopic characteristics and enrichment levels.

Since the terror attacks on September 11, 2001, many publications envisaged doomesday terrorism scenarios, including the deployment of a nuclear device as a potential threat to society. Although this possibility can no longer be excluded, the probability for it to actually happen is relatively low and, in any case, significantly lower than that for a radiological dispersal device to be used in a future terror attack.[iii]

Nevertheless, the issue of losing control over weapons-usable nuclear material has gained prominence in the debate on national security in several countries. Positions in this debate are frequently based on questionable intelligence rather than facts. This undesirable situation is largely due to the fact that information on illicit trafficking of nuclear material is often associated with a high level of secrecy.

In addition, there is a noticeable lack of sharing of relevant information among all parties involved due to the security-sensitive nature of the data and the justified concern by the security community not to reveal any weakness in the physical protection system for nuclear material.

The probability for losing control over nuclear material depends on the amount of material to be secured, the number of storage sites, and the level of physical protection provided by the facility operators.

Large quantities of nuclear weapon-usable material are stored at each of several hundred facilities worldwide. About 1,665 tons of highly enriched uranium (HEU) and 147 tons of plutonium are stored for military uses worldwide.[iv] Comparable amounts are stored at facilities under civilian control. Physical protection practices at these facilities vary significantly, ranging from dedicated nuclear weapon storage facilities under military control, to commercial reprocessing facilities under civilian control, and some research reactors with completely inadequate control.[v]    

In order to avoid the pitfalls of evaluating important security-related decisions from questionable sources of information, this paper discusses only the most reliable currently available data on illicit trafficking of weapons-usable nuclear material, contained in the Database on Nuclear Smuggling, Theft, and Orphan Radiation Sources.

2. Illicit trafficking of weapons-usable nuclear material

The Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO), which combines state-confirmed information with unconfirmed open source data, contains 25 highly-credible trafficking incidents involving weapons-usable nuclear material, i.e., highly-enriched uranium (uranium enriched to 20% U-235 and more) and plutonium-239. Seventeen of these incidents were confirmed by member states to the International Atomic Energy Agency (IAEA) (Table 1). Eight other highly-credible cases were not officially reported to the IAEA Database Program for reasons unknown to the authors, although they have been publicly confirmed by state officials and described in detail by non-proliferation experts and investigative journalists (Table 2).

Table 1. Government-confirmed cases involving weapons-usable material[vi]

Date of Seizure

Location of Seizure

Type and Amount of Material

24 May 1993

Vilnius, Lithuania

100 g of 50% HEU

10 May 1994

Tengen, Germany

6.2 g of Pu-239 (99.75%)

June 1994

St. Petersburg, Russia

2.972 kg of 90% HEU

13 Jun 1994

Landshut, Germany

795 mg of 87.7% HEU

25 Jul 1994

Munich, Germany

240 mg of Pu-239

10 Aug 1994

Munich airport, Germany

363 g of Pu-239

14 Dec 1994

Prague, Czech Rep

2.73 kg of 87.7% HEU

6 Jun 1995

Prague, Czech Rep.

415 mg of 87.7% HEU

7 Jun 1995

Moscow, Russia

1.7 kg of 21% HEU

8 Jun 1995

Ceske Budejovice,Czech Rep.

17 g of 87.7% HEU

28 May 1999

Rousse, Bulgaria

4 g of 72.65% HEU

2 Oct 1999

Kara-Balta, Kyrghyzstan

1.49 g of Pu

19 Apr 2000

Batumi, Georgia

920 g of 30 (±3)% HEU

16 Sep 2000

Tbilisi airport, Georgia

Pu (0.4 g)

2 Jan 2001

Liepaja sea port, Latvia

6 g of Pu in Pu/Be sources

28 Jan 2001

Tessaloniki, Greece

3 g of Pu-239 in anti-static devices

22 Jul 2001

Paris, France

2.5 g of 72.57% HEU

Table 2. Other highly-credible cases involving weapons-usable material


Name of Incident

Type and Amount of Material

3 Feb 1992

Munich, Germany

Pu (115 mg) in smoke-detectors

6 Oct 1992

Podolsk, Russia

1.5 kg of 90% HEU

29 Jul 1993

Andreeva Guba, Russia

1.8 kg of 36% HEU

27 Nov 1993

Sevmorput, Russia

4.5 kg of 20% HEU


Sukhumi,Abkhazia, Georgia

655 g of 90% HEU


Chelyabinsk region, Russia

18.5 kg of HEU


Electrostal, Russia

3.7 kg of 21% HEU


Erlangen, Germany

0.8 g HEU

According to the IAEA state-confirmed reports, the total amount of weapons-usable material seized by law-enforcement authorities is about 9 kilograms. In other credible cases, it amounts to 30 more kilograms. Thus, a total of 39 kg of HEU and plutonium were intercepted during illicit transit, sale, and diversion attempts since 1992. In addition, a cache of 90% HEU reportedly disappeared from a research facility in Abkhazia, a break-away province of Georgia, during the military hostilities between 1992 and 1997. According to different accounts, between 655 g and 2 kg of HEU had been present on site before the conflict broke out and the staff had to leave the facility unguarded. When the specialists from the Russian Ministry of Atomic Energy were finally allowed to enter the facility in 1997, they found no HEU remaining on site. The whereabouts of the material are still unknown and concerns have been raised whether it could have fallen into the hands of criminals or terrorists.

It should be noted that since 1992 HEU has been subject to diversion and smuggling to a much higher degree than plutonium. Intercepted plutonium accounts for less than one percent of the 39 kg. About 380 g of this material were seized since 1992, of which 363 g were part of a mixed uranium oxide batch, 10 g were contained in radioactive sources, and only 6 g were weapons-grade material with a purity of 99.75%. The enrichment level of the remaining 38.6 kg of HEU varies from case to case (Figure 1). At least 4.5 kg were weapons-grade (enriched to 90% and more), which would be insufficient for building a nuclear weapon. However, if the 18.5 kg of HEU intercepted during the attempted diversion from one of the Russian nuclear weapons laboratories in the Chelyabinsk region in 1998 were weapons-grade, this batch alone might have been enough for an advanced nuclear device.

Figure 1. Amounts of seized uranium with various enrichment levels (in gram)

Amount of seized uranium

<>As demonstrated by several known thefts (Luch-Podolsk 1992, Electrostal-St. Petersburg 1994, Electrostal-Moscow 1995), significant amounts of fissile nuclear material disappeared from Russian facilities without being noticed by the facility accounting systems. Therefore, it is possible that more nuclear material has been successfully diverted since the collapse of the former Soviet Union in 1991. It is also likely that gram amounts of HEU and plutonium seized in a number of cases (e.g., Tengen 1994, Rousse 1999, Paris 2001) were only samples of larger quantities of already diverted material. Such a possibility was demonstrated by the four linked cases involving 87 % HEU (Landshut 1994, Prague 1994, Prague 1995, and Ceske Budejovice 1995). A small sample of the HEU was handed over to a German undercover policeman in Landshut, and a follow-up investigation led to the seizure of a large cache (2.73 kg) and two more samples of uranium in the Czech Republic. Subsequent analysis revealed that the material seized in all four cases was identical and likely of the same origin. A similar scheme was used in Germany in 1994, when a 240 mg sample of plutonium transferred to an undercover German intelligence agent in July, was followed by 363 g of the same material delivered on an ordinary Lufthansa flight from Moscow in August. The arrested smuggler claimed he could deliver several more kilograms of already stolen plutonium from Russia. Additional amounts of HEU and plutonium were reportedly promised in several other cases, although the validity of such claims is difficult to corroborate. Therefore, the cumulative amounts of the seized weapons-usable HEU and plutonium may represent only a fraction of the material already diverted from nuclear installations. In this sense, nuclear smuggling is often compared to drug trafficking. For example, the US law enforcement authorities admit to being able to stop between 10 to 40 % of the drugs illegally imported into the country.[vii] These figures are likely to be even lower in developing countries due to poorer border protection. Assuming that the detection rate for HEU and plutonium before they reach the end-user is similar to that of drugs, the quantity of the material that has been successfully diverted and possibly smuggled to the final destination may be 3 to 10 times higher than what has been interdicted so far.

In most of the 25 incidents, the material was stolen or is suspected to have originated from nuclear facilities in Russia. Nuclear research institutions, fuel production facilities, and naval fuel depots have been the most frequent sites for successful material diversion. Russian weapons laboratories located in closed nuclear cities appear to have been guarded better over the past decade. There was only one diversion attempt that can be referred with a certain degree of confidence to a closed nuclear city, and it was successfully interrupted by the Russian security services in the Chelyabinsk region in 1998.

The first theft of weapons-usable material was noted in Russia in 1992, soon after the collapse of the former Soviet Union, accompanied by an economic downturn and impoverishment of the nuclear sector. An engineer involved in the material weighing and accounting procedures at Luch Scientific Production Association diverted almost daily gram amounts of 90% uranium, which were below the detection limits. Over a four month period he had accumulated 1.5 kg of the material. He was arrested by pure chance at a train station in Podolsk on his way to Moscow, where he intended to find a buyer for the HEU. The thief admitted that he had hoped to sell the material for about US$500, so he could buy a new stove and a refrigerator. Once an elite of the Soviet society, nuclear scientists were suddenly faced with dramatically decreased funding, low wages delayed for months, and bleak prospects for the future. As a result, the security of nuclear material became very vulnerable to the so-called “insider” threat from facility employees, who wanted to improve their financial situation by stealing the material and trying to sell it. In all credible thefts of weapons usable material known to date (St. Petersburg 1994, Moscow 1995, Podolsk 1992, Andreeva Guba 1994, Sevmorput 1994, Erlangen 2001), the material was diverted by insiders with access to fissile nuclear material acting both on their own initiative and upon requests by other individuals (e.g., relatives, middlemen). It should be noted that although the identities of the individuals apprehended in the 1998 diversion attempt in the Chelyabinsk region have not been revealed to the public, Minatom officials in Russia confirmed that they were conspiring facility employees. In five out of the six cases, the material was stolen with the purpose of selling it for profit, although, like in the Podolsk case, the perpetrators had only vague ideas as to where to find a buyer.

Involvement of organized crime groups could be a key factor in a successful transfer of diverted weapons-usable material to the end-user in view of their logistical capabilities in the smuggling of weapons, drugs, and people. Therefore, it is very encouraging that no apparent links to organized crime have been identified in any of the 25 smuggling cases. Also, no hard evidence has been found to link any of these cases to specific end-users, such as rogue nations or terrorist organizations, which remain the least known link in the nuclear smuggling chain.

3.           Inherent uncertainties in the current knowledge about illicit trafficking

In order to judge the validity of the current threat assessment, it is essential to also address the inherent uncertainties in the data used for the analysis, such as:

·             Corruption to defeat the physical protection system: The black market value of weapons-usable nuclear material ranges from a few hundred to several thousand US dollars per gram, which is the equivalent of at least several months’ wages for nuclear scientists and security guards in the former Soviet Union or in developing countries. Since corruption is officially acknowledged as a serious problem in many of these countries, it is safe to assume that corruption among personnel guarding and working at nuclear facilities cannot be excluded.

·             Flaws in the material accounting system: Accounting practices for nuclear material face two major limitations: (a) The mass of radioactive material is derived indirectly from counting events of radioactive decay with its inherent statistical uncertainties. This is generally acknowledged in the fuel production by defining a certain percentage of the nuclear material involved in the process as “material unaccounted for” (MUF) – a potential loophole for covert diversion of material which has already been successfully used in Russia; (b) containers holding nuclear material are equipped with seals of various degree of sophistication. Irrespective of the type of seal, these seals can be successfully faked, i.e., material can be diverted without any apparent tampering with the seal.[viii] Provided that material accounting practices rely predominantly on checking the integrity of such a seal rather than the actual content of the container, diversion of nuclear material may remain undetected for extended periods of time.

·             Inadequate equipment for detecting trafficking: The characteristic radiation emitted by nuclear material (mainly alpha particles, together with neutrons) is of a type that most border guards and customs officers cannot detect. Provided that they are equipped with a detection device at all, it is usually a simple gamma radiation detector. The situation is more dire still in case of traffickers familiar with the technical specifications of suitable radiation shielding, since their knowledge enables them to successfully bypass even the checkpoints equipped with alpha- and neutron radiation detectors.

·             Limited prevention of illegal border crossings: Despite major technological and logistical efforts, no country has been able to stop the illegal flow of drugs, immigrants, weapons, or stolen art across its borders. Since the physical amount of nuclear material subject to smuggling is comparatively small, it can be safely assumed that illicit trafficking of the amount of nuclear material needed for a crude nuclear device – about 50 kg of 90% HEU – can be achieved by transporting it across borders on foot or boat using the services of illegal immigrants.

·             Deliberate underreporting of diverted material: Any report about diversion or interdiction of nuclear material highlights the fact that local and national authorities had lost control over the material due to inadequate material accounting and/or physical protection. This fact in itself may be sufficient reason for some countries not to report each and every such incident. Table 2 above shows several incidents involving HEU that had happened in Russia, but were not officially reported to the IAEA. This suggests that there might have been other such incidents, which were not reported by states and therefore went unnoticed by the general public.

4.  Conclusions

Until now, only 25 highly-credible cases of illicit trafficking in nuclear material have become known since recording of such incidents was started in 1991. By comparison, there have been over 800 cases involving illicit trafficking in other nuclear and radioactive material, such as low-enriched uranium, yellowcake, medical and industrial radiation sources, during the same period of time. The inherent uncertainties in our current knowledge on nuclear smuggling make it difficult to judge whether trafficking in weapons-usable nuclear material is really such a relatively rare phenomenon, or whether it was and still is carried out in such a clandestine, professional – in criminal terms – manner, that it remains largely undetected. In either case, it is essential to improve our current understanding of the true magnitude of illicit trafficking in nuclear material, since national security and international stability heavily depend on the correct threat assessment.

Lyudmila Zaitseva established- jointly with the co-author Friedrich Steinhausler- the Database on Nuclear Smuggling, Theft and Orphan Radiation Sources (DSTO) as a Visiting Fellow at the Center for International Security and Cooperation (CISAC), Stanford University.


Friedrich Steinhausler, Chair of Biophysics and Physics at the University of Salzburg, Austria, is Director of the Government Radiological Measurements Laboratory Salzburg. He is currently chairing the NATO CLG Expert Group “Nuclear Terrorism” . He dealt with nuclear safety related issues as a Senior Officer at the International Atomic Energy Agency (IAEA Division of Nuclear Safety, Vienna) and served as member of the International Commission for Radiological Protection (ICRP) on Committee 4.


[i] US President George W. Bush, "…The British Government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa…" , quote from the State of the Union address, 28 January 2003.

[ii] Fissile material with an enrichment level of 20% or more is considered usable for a nuclear weapon according to the definition by the International Atomic Energy Agency (IAEA). However, it should be pointed out that the actual amount of nuclear material needed for building a “crude” nuclear device increases significantly with enrichment levels below 90%.

[iii] Steinhausler, F., “What It Takes to Become a Nuclear Terrorist”. American Behavioral Scientist, 1 February 2003, vol. 46, no. 6, pp. 782-795(14), Sage Publications.

[iv] Institute of Science and International Security (ISIS) at

[v] Bunn, G., Steinhausler, F., “Guarding nuclear reactors and material from terrorists and thieves,” Arms Control Today, Vol. 31, No. 8, October 2001, pp. 8-12.

[vi] IAEA Office of Physical Protection and Material Security, “Comprehensive List of Incidents Involving Illicit Trafficking in Nuclear Materials and Other Radioactive Sources: Confirmed by States”.

[vii] Phil Williams and Paul Woessner, “Nuclear material trafficking: An interim assessment”, Working Paper 95-3, Ridgway Viewpoints (Matthew B. Ridgway Center for International Security Studies, University of Pittsburgh: Pittsburgh, Pa., 1995), p. 2.

[viii] Johnston, R., “Effective vulnerability assessment for physical security devices, systems, and programs,” Austrian Military Journal (OMZ), Special Edition “Nuclear Material Protection” (2003), pp. 51-55.