International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

SUMMARY

The IAEA International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators was held on 4-8 May 2009 in Vienna. Two hundred and forty participants attended the conference, of which 71 were from developing Member States. Fifty Member States, of which 28 were developing Member States, and 4 international organizations participated in the conference. Twenty-six of the 240 participants were female scientists, from both developed and developing Member States. The present conference was held in cooperation with the American Nuclear Society (ANS).

The conference was opened by Y. Sokolov, Deputy Director General, Department of Energy, who presented the interest of the IAEA in accelerator applications related to structural material development and partitioning and transmutation, topics relevant for nuclear power development and their increasing interest in the world. He was followed by W. Burkart, Deputy Director General, Department of Nuclear Sciences and Applications, who spoke on the role accelerator in broad perspective of science and technology, with emphasis on practical development in education, bio-medical applications, material research, food and agriculture, environmental science, cultural heritage. Additional remarks were made by E. Pitcher, representative of the ANS.

A total of 153 oral papers were presented and 145 posters displayed during the 49 sessions of the conference, including the satellite meetings. The main objectives of the conference as stated in the announcement were to promote exchange of information among IAEA Member States representatives/delegates and to discuss new trends in:

• Accelerator Applications including Nuclear Materials Research,
• Accelerator Driven Systems (ADS) and
• Accelerator Technology.

Accelerator Applications for material testing, radiation damage investigations and industrial applications of accelerators were covered in the 11 sessions devoted to:

• Simulation of radiation damage and testing of materials for nuclear systems;
• Research and development of applications for advanced materials;
• Different aspects of industrial accelerator applications;
• Interdisciplinary endeavours.

Modern accelerators can be used in different countries for many applications including such fields as medical radiation physics, radiation biology and experimental nuclear physics, agriculture, sterilization processes, art and improving of environment. The main advantages of accelerators in material science are based on their availability in many research centres and capability of very intensive radiation loads, as compared to extremely durable and expensive neutron irradiation in reactors. They allow detailed studying the main physical mechanisms of radiation effects and investigating the influence of different irradiation conditions on degradation of physical and mechanical properties in materials of practical interest. Selection of different particles and energies can simulate very high-dose irradiation environments in advanced nuclear systems.

During the last decades many results on physical phenomena such as radiation swelling and creep, radiation hardening, helium embrittlement that determine radiation resistance of fission and fusion structural materials have been obtained under neutron and charged particle irradiations. But the detailed comparison and basic understanding of these experimental results under neutron irradiations in fission atomic reactors, neutron spallation sources and charged particle irradiations are still not satisfactory. High-dose accelerator simulation combined with theoretical modelling is a very promising tool for pre-selection of candidate materials for future innovative fission and fusion reactors, and the wide international discussion involving both accelerator specialists and material scientists is gradually progressing.

The topical area of Accelerator Driven System (ADS) in the conference was covered in the 6 sessions devoted to

• ADS: National and International ADS Programmes
• ADS: Experiments and Test Facilities
• ADS: Nuclear data

The main objective of R&D in the area of ADS over past two decades have changed from a deterministically safe nuclear power reactor to a device offering fastest rate of incinerating the plutonium & minor actinides to dispose the radiotoxic spent nuclear fuel of Uranium fuel cycle. In this way, the volume of radio-toxicity burden on a geological repository would be reduced by more than a hundred times while compared to that for open (once-through) uranium fuel cycle. In many member states of IAEA, the disposal of spent nuclear fuel is fast becoming a vexed issue for continuing with nuclear power generation. The topical area of ADS, thus, assumes an important role in the sustainability of nuclear energy.

ADS offers good opportunities due to its inherent deterministic safety feature for the development and qualification with safe in-reactor trials of new fuels and structural materials such as those needed in Gen-IV reactor systems with studies of alternative coolants such as lead and LBE in fast neutron spectrum and studies of future innovative reactor systems for sustainable thorium utilization. Having ADS in the domain of its mandate on peaceful uses of nuclear energy, IAEA should play a major role towards the realization of an ADS demonstrator. A number of structured coordinated research projects should be evolved by organising a few technical meeting of experts on ADS-related problems on subjects of nuclear data, cross-section measurements, materials development and coolant technology.

Accelerator technologies, in particular machine or whole system development were partially covered in the 5 sessions devoted to:

• Operation, Instrumentation and Control
• Research and Development

State of the art technology was presented; particularly striking was the development of RFQ’s and LINAC’s of different kinds. The impressive performance of the PSI cyclotron based accelerator complex calls attention to the question of the more appropriate accelerator for ADS systems (i.e., cyclotron versus LINAC). In particular the development of very compact sc cyclotrons could be a promising avenue to pursue in order to lower costs for different applications including ADS’s. This meeting proves that there is a significant activity in accelerator development due to the highly relevant applications in such fields as ADS programs for nuclear waste transmutation and power generation, proton and hadrontherapy, isotope production, accelerator-based neutron sources for: cargo inspection, neutron diffraction (materials research), nuclear physics (astrophysics, structure, etc.), and also accelerators for a wealth of applications as implantation, ion beam analysis, damage simulation, environmental problems, nuclear physics, education and training. Accelerator technology is gaining its place as a mature technology in the nuclear sector and is likely to play an equivalent role to the one nuclear reactor technology has had traditionally.

The conference was also aimed at enhancing research collaboration between the different Member States to promote education on related topics and to emphasize the potential of accelerator based technology for solving a wide variety of societal issues. In order to fulfil this objective the scientific secretaries organized 6 satellite meetings, with participation of specialized experts on specific themes of interest. The topics of the satellite meetings were

• Nuclear Spallation Reactions,
• Particle Accelerators in Analytical and Educational Applications,
• Application of Electron Accelerators: Prospects and Challenges,
• European Fast Neutron Transmutation Reactor Projects (MYRRHA/XT-ADS),
• Neutron Based Techniques for the Detection of Illicit Materials and Explosives, and
• Applications of Synchrotron Radiation in Natural and Applied Sciences.

Besides scientific presentations the satellite meetings offered the possibility for plenum and round table discussions. Thus specific requests by experts from Member States could be taken into account and discussed. In total 7 round table discussions took place during the meeting. The structure of the satellite meetings was different depending on the topic ranging from mostly presentations to satellite meetings featuring discussions on scientific or educational issues.

The satellite meeting on Nuclear Spallation Reactions was held during 4 sessions.
Spallation reactions are nuclear reactions playing an important role in a wide domain of applications ranging from neutron sources for condensed matter and material studies, transmutation of nuclear waste and rare isotope production to astrophysics, simulation of detector set-ups in nuclear and particle physics experiments, and radiation protection near accelerators or in space. The simulation tools developed for these domains use nuclear model codes to compute the production yields and characteristics of all the particles and nuclei generated in these reactions. The codes are generally Monte-Carlo implementations of Intra-Nuclear Cascade or Quantum Molecular Dynamics models followed by de-excitation (principally evaporation/fission) models. This Satellite Meeting provided experts and competent practitioners a better understanding of the physical basis, approximations, strengths and weaknesses of the currently used spallation models and codes. In addition, presentations of relevant basic experimental data with emphasis on accuracies, detector efficiencies, filters and thresholds have been shown as well as the necessary tools which were developed to perform the benchmark activities, Additionally, the overall status of the benchmark activities was presented with some critical points to handle the benchmark data which were pointed out and the possible solutions of them discussed.

The satellite meeting on Particle Accelerators in Analytical and Educational Applications took place during 4 sessions.
Particle Accelerators have become important tools both, for basic and applied research for the generation of fresh knowledge as well as for applications in a large variety of fields including advanced training and education for new generation of scientists. Industrialized and developing Member States have benefited from this technology to advance their knowledge based technology not only of the industry, but also in material sciences and analytical applications in a large variety of substrates. Although accelerator technology is already well advanced, it continues to be developed with the aim of improving performance, lowering the cost and, producing specialized design for specific purposes. For instance, small accelerators are ideal tools for advanced basic and applied research in universities that covers a wide range of practical analytical applications in environmental sciences, exploration and exploitation of natural resources and materials of cultural and historical value, through techniques such as PIXE, PIGE and micro-beams, in addition to playing a fundamental role in education and training of scientists.
The experience has shown that future educational efforts with small accelerators have to be ‘science-driven’ including hands-on mentored research rather than just the classical pedagogical experiments. Unlike common believe, the tutored exposure to sophisticate instrumentation to young undergraduates is possible and desirable. Undergraduate students with proper guidance can produce first quality papers publishable in referee journals. It is acknowledge that there is a shortage of well trained scientists and engineers in the nuclear field and its applications. This shortage is more pronounced in the developing nations as they are increasingly interested in the installation of accelerators, particularly of cyclotrons for the production of radionuclides for the practice of PET. Government nuclear agencies, universities and the nuclear industry itself may have to play a more pro-active role to address the matter.

The satellite meeting on Application of Electron Accelerators, Prospects and Challenges was held during 8 sessions.
Electron beam (EB) accelerators are used in diverse industries to enhance the physical and chemical properties of materials and to reduce undesirable contaminants, such as pathogens or toxic by products. Electron beam accelerators are reliable and durable equipments that produce ionizing radiation without relying upon radioactive isotopes. EB equipment can be turned on and off as any other industrial electrical equipment. These electron accelerators can be used as tools in basic and applied research, but also in pilot plants for demonstration of the feasibility of a certain radiation processing technology, as well as in industrial-scale facilities. Different end-use areas need accelerators with different energies as well as different under-beam handling systems. For example, wire and cable insulations, heat-shrinkable tubing, and the emerging use of EB cross linked polyethylene tubing for water distribution rely upon a multiple-pass system referred to as a "race-track" system, while EB units for surface curing are installed on printing presses and coatings lines. Service centres often rely upon cart-type conveyor systems that handle diverse product forms and items. Most of the heat-shrinkable films used for food packaging are cross linked before the film is blown into its finished dimensions. Some heat-shrinkable films and tire components are irradiated as sheets. Market surveys indicate that there are more than 1400 high-current EB units in commercial use providing an estimated added value to numerous products of more than 85 billion USD.
Presentations on markets and uses of industrial EB accelerators on a world-wide basis and outlined some of the changes in the market and evolving areas of opportunity were discussed, followed by food irradiation and the use of EB for sterilization and surface decontamination. The effects of irradiation on polymeric materials were covered as well as other EB effects that are of industrial interest. Finally, the topic of EB application for wastewater treatment and the other on the use of EB for sewage sludge treatment on a large scale basis were study in term of cost analyses.

The satellite meeting on European Fast Neutron Transmutation Reactor Projects (MYRRHA/XT-ADS) was held during 2 sessions.
According to the projections published by the Intergovernmental Panel on Climate Change, the median electricity increase till 2050 will be by a factor of almost 5. It is reasonable to assume that nuclear energy will play a role in meeting this demand growth. However, there are four major challenges facing the long-term development of nuclear energy as a part of the world’s energy mix: improvement of the economic competitiveness, meeting increasingly stringent safety requirements, adhering to the criteria of sustainable development, and public acceptability. Issues linked to meeting the sustainability criteria define the scope of the covered discussions. While not involving the large quantities of gaseous products and toxic solid wastes associated with fossil fuels, radioactive waste disposal is today’s dominant public acceptance issue. In fact, small waste quantities permit a rigorous confinement strategy, and mined geological disposal is the strategy followed by some countries. Nevertheless, public opposition arguing that this does not yet constitute a safe disposal technology has largely stalled these efforts. One of the primary reasons that are cited is the long life of many of the radioisotopes generated from fission. This concern has led to increased research and technology development efforts to establish a technology aimed at reducing the amount of long lived radioactive waste through transmutation in fission reactors or hybrid systems like the ADS. A global planning of ongoing collaborations and R&D was presented as well as already foreseen experimental programmes in the framework of fast transmutation system studies.

The satellite meeting on Neutron Based Techniques for the Detection of Illicit Materials and Explosives was held during 7 sessions.
There is a worldwide need for improved technologies for the efficient inspection of cargo containers, especially in the transportation sector. The main objectives are the detection of contraband such as illicit drugs, fissile materials, explosives and weapons and the verification of declared manifests. Technology capable of detecting explosives and drugs has a vital role to play in protecting society. Presently, the detection of concealed contraband is based mainly on the use of X-rays, vapour detection and sniffer dogs. X-rays are widely used since they have many advantages, particularly their high speed and their high resolution images. However the limitations of X-ray inspection techniques have stimulated the need to develop additional methods, including those based on the use of neutrons. Neutron based techniques offer a powerful tool for the detection of illicit materials and bulk explosives, particularly because of their ability to determine composition combined with good penetration. In addition, many neutron-based techniques use accelerators, including neutron generators.
Neutron based techniques offer significant potential for the non-intrusive inspection of parcels and cargo. Neutron techniques are attractive for cargo screening as neutrons have the required penetration, they interact with matter in a manner complementary to X-rays and they can be used to determine elemental composition. However for neutron techniques to be successfully applied to cargo screening they must meet the needs of the industry and, as well, have significant advantages over the established and developing X-ray techniques. Some neutron based technologies may not represent the first level inspection, but rather a second level target-specific system which follows X-ray or other inspection.

The satellite meeting on Applications of Synchrotron Radiation in Natural and Applied Sciences was held during 2 sessions.
This satellite meeting is aiming at the applications of synchrotron radiation (SR) in the field of natural and applied sciences, with a special attention and focus on the light source in Middle East. The Synchrotron-light for Experimental Science and its Applications in Middle East (SESAME) is under construction in Amman (Jordan). SESAME is a project under the auspice of UNESCO and it is an inter-governmental organization. Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestine Authority and Turkey are the members.
Synchrotron sources have a very broad range of applications. There is, however, a strong case for some laboratories to select one or two areas in which they can become a world leader, e.g. the Canadian Light Source is focusing on Environmental science. It can be difficult for a single laboratory working in isolation to cover all scientific fields. Partnerships are necessary to allow expertise to be shared between different facilities. Builders of new sources need to visit existing ones to benefit from their experience. Synchrotron facilities have a strong track record of international co-operation which has paid dividends in the development of the scientific community. Expert emphasis the importance that members of the SR community to know about other techniques, such as ion beam or neutron scattering, in order to use the best tool to answer the questions they are addressing. Relationships with other institutions that house complementary devices are necessary and should be strongly encouraged.

Six commercial exhibitors participated to the symposium. The exhibition provided an opportunity for the participants to interact with the suppliers and get to know the new developments and procedures in the field of accelerators.