CONFERENCE ON INTERNATIONAL APPROACHES TO NUCLEAR & RADIOLOGICAL SECURITY

THE UNITED STATES DEPARTMENT OF ENERGY, NATIONAL NUCLEAR SECURITY ADMINISTRATION’S OFFICE OF INTERNATIONAL MATERIAL PROTECTION & COOPERATION

MINISTRY OF THE RUSSIAN FEDERATION FOR ATOMIC ENERGY(MINATOM) & RUSSIAN RESEARCH CENTER “KURCHATOV INSTITUTE”

RADIOLOGICAL THREAT REDUCTION

BACKGROUND

After the terrorist attacks of September 11th, increasing public apprehension about the security of radioactive sources has evolved worldwide. Some of the radioactive sources used in medical, industrial and agricultural applications contain large amounts of radioactive materials. A number of these sources are unsecured and ‘orphan’ of any regulatory control and may fall into malevolent hands and become a real threat for society. A radioactive source shrouded by a conventional explosive could be easily converted into the terrorist tool dubbed by the media as a ‘dirty bomb’ - a nickname that has exacerbated public unease. Even this simple process is not necessary: the radioactive substance in the source may be easily dispersible; merely opening the container and releasing the substance into the environment is enough to create havoc.

Whether it is a dirty bomb explosion or simply the unsealing of a source, the fact is that this malevolent act would certainly disseminate radioactive particles and spread radioactive contamination. If done an urban environment, a number of blocks could be substantially contaminated; if done in a subterranean metropolitan-train-system, it could paralyse a city. Whereas diffusion of the contamination would moderate and constrain the health effects of such a device (which cannot be compared to the catastrophic effects of a nuclear, chemical or biological weapon), the public may have a different perception. A dirty bomb will not produce a large number of casualties, but terror and psychological trauma will certainly follow its explosion.

The issues we confront are the magnitude of this perceived ‘radiological’ threat and how to reduce it.

THE RADIOLOGICAL THREAT

Benchmarking

Perhaps the best point of reference to quantify the effects of malevolent use of a radioactive source is the accident that took place in the city of Goiania in Brazil around fifteen years ago . This was a security breach affecting a teletherapy unit at an abandoned clinic, resulting in a serious radiological emergency – a case of petty theft but purely non-malevolent. The unit housed a radioactive source containing an easily dispersible compound of the radionuclide cesium-137. Thieves broke in, removed and dismantled the source assembly rupturing the source capsule. Contamination of the city district ensued; fourteen people were overexposed and four died; hundreds had to be evacuated from contaminated homes and more than hundred thousand individuals had to be monitored. The decontamination operations produced 5000 m3 of radioactive waste. The social impact was such that the outlying village to Goiania, where the waste repository was installed, incorporated the three-foil symbol of radioactivity into its municipal flag!

Availability of Radioactive Sources

Radioactive sources are abundant in the world. They are extensively and commonly used in a wide range of medical, industrial, agricultural and research applications. They vary widely in physical size and properties, their amount of radioactivity, and ease of access.

In medicine, radiation sources are used for both diagnostic and therapeutic purposes. Radio-diagnostic techniques commonly employ non-radioactive radiation sources — usually X ray machines — which do not present an evident security threat. When radioactive sources are used for diagnostic purposes — notably in nuclear medicine procedures — the amount of radioactivity used is small and again does not present an evident security threat. Conversely, in radiotherapy, radioactive sources containing large amounts of radioactive materials are common. There are two main radiotherapeutic techniques, namely: the irradiation of tumours either with a radiation beam external to the body (usually termed teletheraphy), or placing the radiation source in contact with tissue (a technique usually called brachytherapy). (Teletherapy can also be performed with “accelerators”, non-radioactive radiation sources which, similar to X ray machines, do not present an evident security threat.) Many medical sources are mainly made from the radioactive element cobalt-60, which is a metal and has a half-life of around 5 years. Less frequently, the radioactive element cesium-137, with a half-life of around 30 years, is employed. Many cesium sources were manufactured using the compound cesium chlorine (CsCl), a salt whose physical form is a highly dispersible powder similar to talc in its spreading properties.

More than 10,000 teletherapy sources containing a capsule of cobalt-60 are in use worldwide. Each source has a radioactivity of around one or several hundred trillion becquerel, or 1014 becquerel, which is equivalent to around 2000 curie . Cobalt, being a solid metal, is not easy to disperse. However, the capsules usually contain around 1000 pellets, each pellet having a radioactive content of around 1011 becquerel or several curie. The available information on external beam therapy sources containing cesium-137 is scarcer. These sources were used when this type of therapy first started but their use was abandoned in favour of cobalt-60. The number of sources still in service (or awaiting disposal or return to suppliers) seems to be limited. The amount of radioactivity of each source is similar to the cobalt-60 sources, i.e. around 1014 becquerel. From the standpoint of security, the difference is the high dispersibility of the cesium compound, which makes them particularly tailored to any malevolent intent to contaminate a public environment. Brachytherapy sources are more abundant and perhaps less amenable to secure than teletherapy sources but their individual radioactivity is orders of magnitude lower. The technique is commonly performed with sources of radium-226, cesium-137, and iridium-192, with a radioactivity content of around 108 to 1011 becquerel per source.

Many more radioactive sources are used in industry through applications such as irradiation of products, radiography, and gauges. There is a large number of industrial irradiators around the world. These are huge installations containing large amounts of radioactivity and are usually employed for sterilizing medical products, such as syringes, and for preserving food. Their number approaches around 300 major facilities worldwide. Their radioactivity content is so high that it is cumbersome to express it in becquerel; they range from 10,000 to 1 million curie per facility — or a million billion becquerel. In addition, there are a few thousand smaller self-contained units, each with a radioactivity of around a hundred trillion becquerel, or a few thousand curie. The radioactive element used in industrial irradiators is mainly metallic cobalt-60, with numerous “rods” containing thousands of pellets of cobalt-60 composing the source, but some facilities are still equipped with sources of cesium-137. The radioactive sources of industrial irradiators could pose a serious security hazard; but they are not easy to divert, as the perpetrators would probably die almost instantaneously from overexposure.

Numerous radioactive sources are used for purposes of industrial radiography, the number estimated at several tens of thousands. About 80% of the sources contain the radioactive element iridium-192; the remainders are sources of cobalt-60, selenium-75 and ytterbium-169. The typical activity is around 50 to 100 curies each or around three trillion becquerel. Their physical form is usually encapsulated metal, which makes them robust to desegregation. While these sources are therefore unlikely to pose a serious contamination hazard, they can produce significant injuries to individuals in contact with the source. It is relatively easy to steal an industrial radiography source, but difficult to accumulate a larger number as they are usually stored at different industrial locations. Currently, around 10,000 iridium-192 industrial radiography sources are supplied annually and replaced approximately every half a year. Their activity is around 1 to 300 curies, but typically 50 or 100 curies. Their physical form is a metal pellet. The supply of cobalt-60 sources is a few hundred per year with more than a thousand in circulation. Their activity is between 10 to 500 curies, but mostly 100 curies. In addition, around 1000 sources of selenium-75 and ytterbium-169 are supplied annually; their activity range is about 10 to 30 curies. Completing the industrial picture, millions of sources having a relatively low radioactive content are used as gauges and in other applications. They usually contain cobalt-60, cesium-137, or americium-241, come in many physical forms and their regulatory control is particularly gentle in many countries. Unless they are accumulated, the risk involved is minor.

But perhaps the most serious inventory of radioactive sources from the security perspective refers to specific unusual applications in the past. A notable example concerns thermoelectric generators containing ten thousands of curies of strontium-90– or an amount similar to the radioactivity of this radionuclide released during the Chernobyl accident. These generators were used in the former USSR supplying energy to navigational beacons for a possible dual purpose (civilian and military). Large movable irradiators were used in agriculture, notably the ‘ear of corn’ irradiators in the former USSR. They were mounted on trucks and contained large amounts of radioactivity of the dispersible compound cesium-137. Finally, little is known about the many radioactive sources used for military applications.

Orphan Sources

While the vast majority of radioactive sources are under the control of competent governmental regulatory authorities, the world is abundant in ‘orphan sources’, or sources that have never been subject to regulatory control, or were initially regulated but eventually abandoned, lost, misplaced, stolen or removed without authorization. Many industrial and medical radioactive sources are believed to be in this state and serious incidents involving orphan sources have occurred in the newly formed States of the former USSR. Following the dissolution of the former USSR, regulatory control of these sources was lost. Many sources have been abandoned in unknown locations; others are sited in unsecured places; all are amenable to misappropriation. A number have already have been found in the newly independent Republics, notably in Georgia. Obviously, these orphan sources are easier to divert than regulated sources and are prone to fall in malevolent hands. An embezzled source can be converted without major difficulty into a dirty bomb, particularly if the perpetrator is willing to disregard his or her personal safety.

SECURITY OF RADIOACTIVE SOURCES

A Safety Issue

Worldwide, no tight security measures are in general applied to chemical or biological products and radioactive sources are not an exception. Source security has traditionally been confined to preventing accidental access to the sources or petty theft (such as stealing shielding materials). Certainly no sophisticated anti-terrorist security measures are commonly in place and even well regulated radioactive sources could be stolen and diverted with relative ease, as is the case for most chemical or biological substances. This problem was widely recognized long before September 11th and the need for securing radioactive sources has always been high on the agenda of the international radiation safety community. It certainly was an integral part of the radiation safety programme of the International Atomic Energy Agency (IAEA) – the so-called UN nuclear watchdog - where source security, or the prevention of relinquishing control or of unauthorized possession of radioactive sources, has always been considered an essential precondition of radiation safety . (One only has to look as far as the Goiania accident and other similar accidents for illustration of how security is a subsidiary of safety: in each case, insecure sources led to several serious safety problems involving injuries and fatalities.) Radiation safety is concerned with preventing adverse health and environmental impacts from radiation sources ... whatever the cause. Conversely, the security of radioactive sources is about preventing loss of control, either inadvertent or intentional. Inadvertent loss can arise because a source is misplaced, forgotten, accidentally lost, or insecurely stored. Until recently these mishaps were the main focus of radioactive source security guidance and therefore are already covered by existing IAEA programmes. Serious consideration of intentional loss of control is relatively new and can occur for financial or for malevolent reasons. Financial reasons include: illegal sale for profit, avoidance of costs or other burdens of ownership (e.g. dumping to avoid disposal fees), and extortionist threats. Malevolent reasons for obtaining radioactive material include: an intent to harm others, and terrorist threats.

The IAEA Mandate

The IAEA has an international mandate in radiation safety: It is authorized by its Statute to establish international radiation safety standards and to provide for their application at the request of a State. In setting up these standards as far back as in 1992, the IAEA established international requirements for the security of radioactive sources, which require inter alia that radioactive sources “shall be kept secure so as to prevent theft or damage ... by ensuring that: control of a source not be relinquished ...; a source not be transferred unless the receiver possesses a valid authorization; and a periodic inventory of movable sources be conducted ... to confirm that they are in their assigned locations and are secure…”. The IAEA also has a mandate in the implementation of relevant international legally binding undertakings, notably the Conventions requiring notification of and assistance in radiological emergencies, which would be applicable in a radiological crisis caused by an unsecured radioactive source.

Assisting Developing Countries

As radioactive sources are used all over the world, even in the smaller and less developed countries, the IAEA launched a technical co-operation project aimed to create regulatory infrastructures for controlling these sources in 52 developing Member States of the IAEA (recently expanded to 83 Member States ). By September 2001 about 80% of the participating countries had established an inventory of their radioactive sources but about 50% still lack an effective system of authorization and control. IAEA assistance, however, can only be rendered to IAEA Member States; about 50 countries (and a number of political entities not even recognized as countries) are not IAEA members. In these territories, radioactive sources are also being used but without IAEA assistance and probably the local authorities are not even aware that they have a security problem to deal with.

Governments Awareness: the International Action Plan

Governments gradually became aware of the international dimensions of the security threat associated with radioactive sources. By 1998, hundreds of specialists and governmental representatives met at the first international conference on the issue, which was organized by the IAEA jointly with Interpol, the World Customs Organization and the European Commission, in Dijon, France. The Dijon Conference produced recommendations that the IAEA General Conference made into an international Action Plan to strengthen the global safety and security of radioactive sources. Within this Plan an internationally agreed identification of the sources that were deemed to pose a potential threat, and a non-binding ‘Code of Conduct’ for States was established. In December 2000, national regulators of radioactive sources attended an international conference convened by the IAEA in Buenos Aires, Argentina. The Buenos Aires Conference recommended reinforcing the Plan, which was subsequently revised and strengthened by the IAEA Board of Governors and General Conference …ironically…on 10th September 2001… one day before the terrorist attack on New York and Washington … when a different story would commence.

AFTER SEPTEMBER 11TH

A New Threat

The September 11th attacks demonstrated a new kind of malevolence, identified by the perpetrators’ intent to induce widespread panic and harm among the civilian population, the ability to work with modern technologies, and a suicidal approach. In summary, the new considerations that September 11th has brought to radioactive source security are firstly: the more deliberate, determined effort to acquire sources for malicious purposes; and secondly: the lack of personal safety considerations in their acquisition and use. This opens up new dimensions to the problem of securing potentially harmful substances in general, including the radioactive substances that constitute radioactive sources.

The IAEA Response

The IAEA’s 45th General Conference, the week after the September 11th nightmare, passed a resolution requesting the identification of possible threats by acts of nuclear terrorism. The IAEA characterized four main possible nuclear terrorist threats: a) theft of a nuclear weapon; b) acquisition of nuclear material; c) acquisition of other radioactive material; and d) violent acts against nuclear facilities. It also developed a draft proposal for new measures addressing these threats and, as a result, the IAEA Board of Governors adopted a new Nuclear Security Plan of Action in March 2002, which is funded by voluntary contributions. Work within the plan is grouped under eight areas: physical protection of nuclear material and nuclear facilities; detection of malicious activities involving nuclear and other radioactive materials; state systems for nuclear material accountancy and control; security of radioactive material other than nuclear material; assessment of safety/security related vulnerability of nuclear facilities; response to malicious acts, or threats thereof; adherence to and implementation of international agreements, guidelines and recommendations; nuclear security co-ordination and information management. Thus, the Board recognized the significance of the radiological threat in the post-September 11th world and instructed the IAEA to strengthen its activities in this field taking account of the new dimensions.

REDUCING THE THREAT

Tuning the Basic Objectives

In face of the post-September 11th reality the overall international efforts in the security of radioactive sources is being enhanced. The basic IAEA objectives remain: assisting Member States to create and strengthen national regulatory infrastructures to ensure that radioactive sources are localized, registered, secured and controlled from ‘cradle to grave’. While these objectives are immutable, their application has to be adapted to the new security dimension. Before September 11th, it was targeted at breaches in security caused by innocent mistakes or petty theft. Today, the scope is being widened to include malevolence and terrorism.

Strategy

The IAEA’s strategy for addressing this problem is to first evaluate the possible radiological threats and postulate scenarios and from these to determine which radiation sources are most ‘desirable’ from a terrorist’s perspective. An assessment is then made of where these sources are located and how terrorists might acquire them. Prevention or minimization tasks logically follow from this analysis. First of all one should attempt to prevent acquisition of desirable sources by those with malevolent intent. Should such attempts fail, efforts should be made to delay acquisition in order to allow law enforcement time to respond, and/or to quickly recognize the material loss. Assuming that radiation sources have been acquired, the next level of action is to attempt preventing the use of any such sources. Finally, if this fails, one must strive to minimize the effectiveness or consequences of any such use.

Threats and Scenarios

The threats or objectives usually considered in potential cases of radiological terrorism are: a) to kill or injure; b) to create social and economic disruption; or c) to create a strong bargaining position. As most experts recognize, the kill or injure threat is more difficult to achieve than most members of the public would envisage. Possible scenarios include the localized dispersion of sufficiently large quantities of radioactive material to cause deterministic effects from contamination and placement of a large source in a hidden location. Creating social or economic disruption is much easier than killing or seriously injuring someone. Social disruption will usually also result in economic disruption, and relatively small quantities can be ‘effective’ for these purposes. Scenarios considered include the spreading of radioactive material by various means, including surface, water, or air dispersion. Radioactive material introduced into foodstuffs would also be effective. In addition, a facility such as an irradiator or a shipment of significant radioactive material could be sabotaged. In trying to create a strong bargaining position the threat to use radioactive material may be enough to have the desired effect. Scenarios include taking over an industrial irradiator or a vehicle transporting radioactive material with the threat to blow it up.

‘Desirable’ Sources

The kill or severe injury threat generally requires high activity sealed sources with penetrating gamma radiation or radiation generators. The social or economic disruption threat needs medium to high activity dispersible material, preferably with a long half life, since it requires clean-up rather than decay. Alpha-emitting material (e.g. Pu) might also be ‘better’ because of the ‘fear’ factor and the difficulty of detection. The bargaining threat could result from the take-over of an industrial irradiator, a research reactor or a hospital teletherapy unit. To identify the locations of the ‘desirable’ sources that need protecting, available inventories can be used whenever possible. However, many countries do not have national inventories of radiation sources. Hence for these, it would also be important to develop a national strategy action plan for detecting and locating sources that are either disused or out of regulatory control. It should also be recognized that, from the terrorist’s viewpoint, the risk of detection is minimized if the material is acquired close to where the terrorist plans to ‘use’ it.

Acquisition

There are several ways in which ‘desirable’ radioactive sources can be acquired. These include legal purchase, black market purchase and theft. The first step in the prevention of acquisition is to try to prevent the legal purchase of significant radioactive materials by terrorists. Clearly this is not simple but there are some measures that can be taken, including performing background checks on those requesting licenses, and reviewing purchase orders for radioactive material for consistency with a stated purpose. It would also be appropriate to question whether the isotope and activity are appropriate for the industry or for the use stated in the request, and to increase administrative controls such as accounting and tracking of radioactive material.

The prevention of illegal purchase on the black market basically means detecting and finding radioactive material that may already be out of regulatory control. For this purpose it is appropriate to use standard intelligence methods to trace radioactive sources in a similar manner to those used for nuclear materials. Monitoring for radiation at appropriate locations such as at certain border crossings also has its place. Finally, trying to stop the financial resources of the terrorists will hinder their purchase of black market materials because of the high prices usually demanded.

Clearly, theft of radioactive sources is easiest from locations where security is weak, such as at hospitals and universities. In addition, there might be some concern about security during transport and those countries that do not have the desired level of security currently in place. There would appear to be a need for some increase in the level of physical security for ‘desirable’ sources. The difficulty is: which aspects of security can be added that willstill enable the sources to be used for their intended, beneficial purpose? It also logical to promote the collection and removal of disused sources, especially those in vulnerable locations. Measures to delay thieves to allow response by law enforcement, or measures to provide early detection of the theft of sources is the next best step if the theft itself cannot be prevented.

Prevention

Once the radioactive material is already on the black market or in the hands of terrorists, the strategy is to try to prevent the use of such material. To this end, it is beneficial to identify countries, or areas where the sources are most likely to be, and to target those countries for detection activities. It should be recognized, however, that border monitoring and aerial surveys may be of limited use to detect radioactive material because of deliberate shielding of the material and the ease of alternate routes across many borders. If monitoring is used, the focus should be on areas of high potential risk or benefit. The benefit of standard intelligence activities should not be underestimated, since they have played a major role in finding nuclear materials. All significant nuclear materials that have been seized have been the result of intelligence operations, not of detection by border monitors.

Minimization of Consequences

If one fails to prevent terrorists acquiring material or using it, one can only resort to minimizing the consequences of that use. To this end, improvements in the emergency response capabilities of Member States could be made, especially those that are in higher risk areas or where existing capability is poor. Similarly, there are always ways in which the IAEA’s ability to assist Member States can be improved.

OUTLOOK

New Proposals

What initiatives can be undertaken to reduce the threat? Some are not new, are of a general nature and can be highlighted as follows:

• The global situation of orphan sources should be more precisely assessed.
• The Code of Conduct should eventually be converted into a legally binding undertaking (States do not seem ready to take this essential step yet, as they apparently first wish to agree on a precise categorization of the sources that should be covered by the Code, an action that the IAEA has already initiated).
• International assistance to developing countries should be augmented (an unsecured source anywhere can be used malevolently everywhere) and such assistance should cover not only IAEA Member States but non-Member States as well.
• A system for appraising national compliance with international security criteria should be established.
• Significant radioactive sources should be made easy to track and their physical characteristics should be more amenable to security criteria.
• The possibility of a new international marking of sources and devices should be further investigated.
• Checkpoint technology to monitor border crossings for detecting illegal movement of sources should be improved and countries should be encouraged (and helped) to implement it and to locate orphan sources.
• The complex issues related to the security during the transport of radioactive materials should be re-evaluated with the aim of strengthening control and confidentiality (a top priority on future agendas).
• The IAEA’s illicit trafficking database should be improved to facilitate the focusing of efforts.
• The international emergency response capabilities called for by the notification and assistance Conventions must be enhanced; in particular, the IAEA’s Emergency Response Centre should be upgraded and there should be further development of regional emergency action teams.

More specific initiatives related to the major thrusts of the new work are as follows:

• to remediate existing disused and orphan sources; and
• to prevent more sources becoming orphaned.

In order to regain control over existing orphan sources, and to ensure appropriate disposal of disused sources, it seems that there is a need to develop criteria for the prioritization of assistance to countries. This is simply because resources are limited and search campaigns are both time-consuming and expensive. The IAEA can assist Member States to help themselves by the development of their own national strategy action plans to locate and recover large orphan sources. Incorporated in the national strategies document will be guidance on the criteria for trying to detect sources by radiation monitoring (border, area, aerial surveys). How, when, where and why does one perform radiation surveys? Once national plans of action have been developed, the IAEA might be able to help implement these plans as appropriate and as resources allow.

To prevent future sources becoming orphaned, one urgent priority is to issue guidance on security requirements for radioactive sources. This is currently being developed. Once published, training on these requirements and an appraisal services can be offered. Additional actions to minimize the radiological terrorism risk could involve facilitating agreements with suppliers and regulators on necessary controls and checks to ensure the validity of purchase orders for significant radioactive sources. There also seems to be a need for the development of criteria for the design of certain sources in order to minimize their attractiveness for terrorist use. It would be beneficial if, for example, no dispersible or soluble forms of the radioactive material were employed.

Education and training, particularly through a train-the-trainers approach, should be an essential element of any new initiative to improve the security of radioactive sources and reduce the threat of terrorism.

The Trilateral Initiative

Recently, the Russian Ministry of Atomic Energy, the US Department of Energy and the Agency reached an agreement for a new initiative termed Securing and Managing Radioactive Sources. A tripartite project, which will be organized and managed by the Agency, will aim at securing radioactive sources in the new independent States of the former USSR. Its objectives are:

• developing an inventory of relevant sources, and their actual or likely location;
• locating the sources;
• recovering them;
• storing them in a secure manner;
• recycling the radioactive sources.

The Agency, with the consent of the parties, may invite other Member States of the to contribute to the implementation of the project in areas of their specific expertise.

CONCLUSION

In conclusion, while a large number of actions to minimize the radiological terrorism threat are already being undertaken by the IAEA, more could and should be done if funds were available. A monumental security agenda lies ahead for national governments, for the IAEA, and - last but not least - for the professional radiation safety community! The challenge will be to address the problem effectively, weighing up its importance relative to the scale of the threat posed by terrorist use of other chemical and biological agents.