Countering Nuclear and Radiological Terrorism

The non-proliferation rationale and achievements of the collaboration between the UK and Russia for a personnel redirection programme in the Closed Nuclear Cities is described. A framework for the interaction between demand and supply dimensions of proliferation threats is developed to show how redirection programmes to enable WMD specialists move into civilian activities reduce these same threats. Early results from the UK-Russia Closed Nuclear Cities Partnership are presented and compared with the parallel US funded Nuclear Cities Initiative and similar local economic development measures.

The purpose of this paper is twofold: firstly, to summarize objectives and provisions of the 8 July 2005 Amendment to the Convention on the Physical Protection of Nuclear Material; and, secondly, to discuss implementation of the physical protection provisions of the Amendment in terms of the kinds of institutions and organizations within a State that would be expected to have a role in ensuring the effectiveness of the State’s regime for the physical protection of the nuclear material and nuclear facilities used for peaceful purposes within the territory of the State, coupled with how those institutions and organizations could be expected to fit together to form an integrated physical protection system.

Since September 11, 2001 there has been a fundamental transition in the way we view radiological sources and devices in our environment. Ionizing Radiological Sources, (IRSs) which serve a multitude of important medical, industrial, and research needs in our modern society, were not so long ago viewed as common place in an industrialized society, only of concern to health and the environment if control is lost accidentally. But, 9/11 taught us that those bent on indiscriminant terror are capable of taking the most common place elements of our advanced technology and turning them into effective weapons of mass destruction. And radiological sources quickly became the object of concern as a potentially disruptive threat to our national security.

Calculation study has been carried out to analyze the proliferation resistance of different scenarios of nuclear fuel cycle organization. Scenarios of stable and developing nuclear power were considered with involvement of thermal and fast reactors. The attention was paid mainly to the cycles with extended plutonium breeding on the basis of fast reactor technology, and to the schemes of fuel cycle organization allowing to minimize the proliferation risk.

The purpose of this paper is both to present a reflection on the international policy evolution after the end of Cold War, with the emergence of islamic terrorism and also what we consider main aspects to take into account when dealing with terrorist possibility of having improvised nuclear devices (IND’s).

Both sealed and unsealed radioactive sources are used in hospitals throughout the world for diagnostic and therapeutic purposes. High activity single sealed sources are used in teletherapy units, although these are becoming less common as they are replaced by linear accelerators, and in blood irradiator units, which are in widespread use. Lower activity sealed sources are used in brachytherapy. High activity unsealed sources are used typically for the treatment of thyroid cancer and neuroblastoma in inpatients while diagnostic doses of unsealed radioactive materials have much lower activities. In the case of a central radiopharmacy producing patient doses of radiopharmaceutical for several Nuclear Medicine departments, however, quite large amounts of radioactive materials may be held. Hospitals are, by their nature, less secure than other licensed nuclear sites and the ever-changing patient/visitor (and staff) population is a further complicating factor. Hitherto, security of radioactive materials in hospitals has tended to be considered from the perspective only of radiation safety but this approach is no longer sufficient.

Nuclear power plants have long been recognized as potential targets of terrorist attacks, and critics have long questioned the adequacy of the existing measures to defend against such attacks. The 11-S 2001, 11-M 2004 and 7-J 2005 attacks in USA, Spain and UK illustrated the deadly intentions and abilities of modern terrorist groups. These attacks also brought to surface long standing concerns about the vulnerability of nuclear installations to possible terrorist attacks. Commercial nuclear reactors contain large inventory of radioactive fission products which, if dispersed, could pose a direct radiation hazard on the population. The reactor pressure vessel (RPV), which contains the nuclear fuel, is the most critical component of the plant. This paper shows that small amount of explosive material can produce irreversible damage in the RPV and the release of radioactive material. Therefore, access of working personal to the vicinity of the RPV during the refuelling outage should be strictly limited. It should be considered a high priority security issue.

The paper presents a review of the main principles for technologies and materials protection from unauthorized proliferation and application to be considered in nuclear reactors designing. Nuclear power features certain operations sensitive to nuclear weapons proliferation (such as separation of uranium isotopes (enrichment), long storage of spent fuel, processing of spent fuel, plutonium and/or uranium recovery from spent fuel, storage of recovered fissile materials). Proliferation resistance is defined as a nuclear energy system characteristic that impedes the diversion or undeclared production of nuclear material, or misuse of technology with the purpose of acquiring nuclear weapons or other nuclear explosive devices. The basic principles of non-proliferation established in the INPRO international project sponsored by IAEA have been discussed as implemented for designing of the innovative nuclear energy systems based on fast leadcooled nuclear reactors.

The nuclear power plants (NPPs) world-wide are generally very robustly designed and constructed, capable to stand very extreme conditions. Small design differences from this point of view can be found among the various reactor types of the same generation; PWR, WWER, etc. The NPP structures are thus designed to accommodate all originally thinkable unwanted conditions, to cope with various extreme scenarios and respond safely to the various considered initiating events. In addition to the robust design, a series of complex redundant and diverse safety barriers, following a defence in depth concept, have been developed to avoid negative consequences, or at least mitigate the consequences of the events. Recently, questions and debates are appearing with regard to the vulnerability of the NPPs and their possible exposure to external threats; like for example terrorist attacks involving few individuals able to by-pass security and introducing small charges of explosive inside or near-by such containments. The role of the structural materials is in these situations very important for the safety of the NPP. The worst consequences of an event can contemplate of course huge environmental damage, like release of radio-activity combined with possible human losses and considerable direct costs, and financial and logistic indirect consequences. Such negative consequences are especially impacting the nuclear industry; in fact, it can be foreseen that a single accident or serious incident may put in danger the complete NPP fleet operation simply due to public opinion justified pressure. The response of the structures subjected to non-design impacts is discussed and reviewed in this paper. Although the main focus is on structural integrity, the paper also discusses the overall risk assessment of terrorist attacks presenting the link between structural analyses and plant risk analysis.

In the twentieth century, radioactive sources have become extensively used in everyday life. These sources, in the hands of terror organizations, can become a threat to the security of civilized nations, causing severe disruption to normal life. One of the main challenges of the civilized world is to keep ahead of the terrorist organizations and take appropriate preventive measures in order to prevent and reduce to minimum the impact of their actions. In order to succeed, a joint and comprehensive effort has to be undertaken to address the scientific, technological, organizational, sociological, psychological and educational aspects of the radiological terrorism threat. In this paper, some of the main activities required for preventing radiological terror events, and the way in which a modular response plan can be prepared are discussed.

The initial stage of dispersion of ⁹⁰Sr radiological dispersion device (dirty bomb) in a terrorist event was investigated on the basis of a numerical solution of the full system of Navier-Stoks equations. Maximum inhalation doses at the level of ≥1, ≥5, ≥10, ≥50 mSv are used as evaluative criteria to assess probable consequences. The intentional release of a relatively small amount of ⁹⁰Sr using a conventional explosive has the potential to cause internal exposure to beta-radiation with relatively high maximum inhalation doses achieving hundreds of mSv, but the spatial extent of the area within which high exposures might occur is very small with most of the population receiving maximum inhalation doses between 1-10 mSv. The extent of radiation contamination (area and activity) is dependent on ⁹⁰Sr particle size, the height of release, and local weather conditions.

Under the auspices of its Euratom Research Framework Programmes, the European Commission (EC) has supported the development of the comprehensive decision support system RODOS (Real-time On-line DecisiOn Support) for off-site emergency management after nuclear accidents for more than a decade. Many national research programmes, research institutes and industrial collaborators contributed to the project, in particular the German Ministry of Environment, Nature Conservation and Reactor Safety (BMU). The RODOS system can be applied to accidental releases into the atmosphere and various aquatic environments within and across Europe. It provides coherent support before, during and after such a release to assist the analysis of the situation and decision making about short and long-term countermeasures for mitigating the consequences with respect to health, the environment, and the economy. Appropriate interfaces exist with local and national radiological monitoring data systems, meteorological measurements and forecasts, and for the adaptation to local, regional and national conditions in Europe. Within the European Integrated Project EURANOS of the 6^th Framework Programme, the RODOS system is being enhanced, among others, for radiological emergencies such as dirty bombs attacks, transport accidents and satellite crashes by extensions of the nuclide list, the source term characteristics and the atmospheric dispersion model.

In the present situation, it is to be expected that an attack using a radiological dispersion device is possible, if not probable. Where or when it will happen remains of course very uncertain, but preparedness is primordial, if an adequate response is to be given. This paper will not include aspects of protection of highly active encapsulated sources; aspects of transport security; prevention and response in a context of improvised nuclear devices; proliferation issues at the level of states; risks and consequences of attacks upon nuclear facilities or clean-up and remediation strategies. It focuses on a few remaining issues: an adequate response after an attack with a radiological dispersion device (RDD), with focus upon public health, reassurance and limitation of public disruption, and secondly on a comparison between an adequate response in case of an RDD as compared to a 'normal' radiological or nuclear accident related to a facility.

Decision support system RECASS NT was developed and is still enhancing in Federal Service Roshydromet for providing on-line estimates and prognoses of radiation and chemical situation in the event of an emergency, including acts of terrorism, as well as to estimate transboundary pollutants transport. RECASS NT has been installed at all ten NPPs of the Russian Federation, in Crisis Centres of Roshydromet, concern Rosenergoatom and Minatom, at plants for destroying chemical weapon. The paper will describe the structure of RECASS NT system and discuss its possible application in case of an emergency on examples of using the system during radiation emergency response exercises at NPPs. RECASS NT can be used for developing recommendations regarding time when antiterrorism operations are better to be started with a view to minimize damage.

The presentation outlines a mobile radiological facility, designed for determining of the source term parameters and atmospheric transport and dispersion parameters in the near zone during an accident. Those parameters serve as input to the RECASS NT system for forecasting atmospheric dispersion of pollutants. Information is generated by means of field simulation of contaminant transport and dispersion through creating a cloud of superlight tracers (chaff) at the simulated release height and tracking its transport and dispersion with the radar. Results of field experiments using the mobile radiological facility carried out in the vicinity of the Kola NPP and Kursk NPP are described.

precipitates identified with infrared (IR) transmission microscopes in radiation detector-grade CdZnTe (CZT) crystals correlate precisely with poor charge collection. This indicates that Te precipitates adversely affect the electron charge collection efficiency and thus the performance of nuclear radiation detectors produced from the crystals. By employing different techniques we investigated how Te precipitates affect different CZT devices. Our measurements indicate that Te precipitates put limits on the sizes, electrode configurations and spectral performance of CZT detectors. These limits can be It has been recently demonstrated that individual Tellurium (Te) relaxed by lowering the size and density of Te precipitates in the detectors.

Radiation sources widely used in industry, medicine, agriculture, research and education are most dangerous from the viewpoint of their widespread and easy access. The probability that these sources will be stolen and used to assemble a radiological dispersive (RDD) is not negligible. Such a device can be used by terrorist groups for the purpose of contamination of industrial centers, airports, seaports and residential areas, which can affect a large sector of the economy of a country. Detonation of a RDD can lead to death and exposure of the population to radiation, but, as a whole, the use of the bomb is aimed at creating panic among population, causing economic damage and social shock to the society. In this work, ways to reduce the threat of radiation sources obtained outside and within a country will be discussed.

The threat of possible nuclear and radioactive terror causes the necessity of stringent control of trafficking of nuclear materials. The detecting abilities of currently used ≪passive≫ detection systems (radiation monitors) had practically reached their limits, especially in case of masked or shielded radioactive and fissile materials. These systems cannot detect non-radioactive materials such as lithium or heavy water since these materials do not emit the ionizing radiation.

Simultaneous measurement of neutron and gamma radiation is a very useful method for effective nuclear materials identification and control. The gamma-ray-neutron complex described in the paper is based on two multi-layer ³He neutrons detectors and two High Pressure Xenon gamma-ray spectrometers assembled in one unit. All these detectors were callibrated on neutron and gamma-ray sources. The main characteristics of the instrumentation, its testing results and gamma-and neutron radiation parameters, which have been measured are represented in the paper. The gamma-neutron sources and fissile materials reliable detection and identification capability was demonstrated.

A novel method of simultaneous detection of concealed explosive substances and heavily shielded nuclear materials is described. Experimental setup based on a portable DT neutron generator and detectors of neutrons and γ-rays has been created and tested. Results of tests with real fissioning materials are presented.

A prototype of portable sealed neutron generator has been recently built to deliver 14 MeV neutron beams tagged by a YAP:Ce α particle detector in order to produce simultaneously multiple neutron beams to irradiate complex samples. Preliminary tests performed at the Institute Ruder Boskovic, Zagreb (Croatia) on the detection of explosives and fissile materials in maririme containers are presented.