Thursday, February 9, 2012

IAEA: Research Reactors: Ignored Yet Irreplaceable


9February 2011

Research Reactors: Ignored Yet Irreplaceable

Rising water in a tomato plant
Rising water in a tomato plant: when scanned and illuminated with neutrons in a research reactor, the "heavy" water (black) stands out. This helps agricultural scientists from Japan and Potsdam conduct the first studies on how a plant absorbs and distributes water. (Photo: HZB)
They are small and do not produce energy for electricity production. But for over half a century, research reactors have been fostering scientific innovation and education in more than 50 countries around the world. They host ground-breaking experiments from the nuclear industry's best minds and serve as training centres for students and nuclear scientists of the future.
There are close to 240 research reactors in operation worldwide as of December 2011, according to the IAEA's Research Reactors Database (RRDB). Many of these are in developing countries in Africa, Asia and Latin America, where they are being used to improve overall scientific knowledge and help in the application of nuclear techniques to solve developmental challenges in health care, agriculture and industry.
Versatile Neutrons
The primary purpose of these non-power reactors is to provide a neutron source for research and other purposes. Neutrons are mainly used for materials testing and the production of isotopes for medicine and industry. Their applications are very diverse, ranging from testing of airplane turbines, to detecting arsenic poisoning in a hair sample or producing life-saving isotopes.
In the decades ahead, research reactor programmes are expected to make yet greater contributions - particularly in education and training, basic research, materials science and nuclear medicine, these reactors will play important role in the development, advancement and transfer of these technologies to and among developing countries. The IAEA, for its part, is committed to support its Member States in developing and improving their research reactor programmes to foster technology exchange and innovation.
"Among the activities that the IAEA organizes to support research reactors are technical meetings, publications and projects, which include the supply of equipment, human skill development and the transfer of knowledge via fellowships, scientific visits and peer reviews," said Ed Bradley, Nuclear Engineer at the IAEA Research Reactor Section.
Recent initiatives focus on three key areas: medical isotope production; education and training; and neutron imaging applications.
Production of Medical Isotopes
In any given second, all over the world, a medical patient undergoes a life-saving diagnostic imaging procedure that would not be possible without the use of radioactive isotopes, also known as radionuclides. Diagnosing cancers, heart or neurological diseases would not be possible without them. Produced in research reactors, Molybdenum-99, its derivative Technetium-99 and other isotopes are in growing demand worldwide, as national health programmes continue to expand and develop. There are only a few research reactors worldwide that produce these isotopes, and their temporary shutdown for age-related maintenance in 2008-2010 immediately triggered a global supply crisis. Depending on location and timing, the crisis cut the supply of the radioisotopes by 20 to 70 per cent. This was particularly serious, since the radioisotope has a very rapid decay rate and has to be produced weekly. Furthermore, the demand for the isotope is growing by about 3 to 5 per cent annually.
The IAEA joined international efforts to mitigate the effects of the supply shortage. IAEA support led to reactors in Poland and Czech Republic joining the community of molybdenum producers. IAEA organised meetings to update Member States on the crisis during the General Conferences in 2009, 2010 and 2011. An on-going programme helps Member States secure the supply of these isotopes by sharing molybdenum production technology, fostering international partnerships and encouraging the diversification of the sources of supply. It succeeded in preventing prolonged impacts from the crisis by promoting the exchange of best practices, and building effective regional and multilateral partnerships.
Education and Training
Research reactors' benefits extend well beyond medical applications. Nuclear engineers, as well geologists, physicists or chemists benefit daily from practical training in a research reactor. Many of these reactors are on university campuses, and are used to teach courses for nuclear engineering or physics programmes and support other science programmes, such as chemistry and biology, via specific reactor applications. And, research reactors operated for commercial purposes (such as isotope production) can offer courses or technical tours for scientists interested in their many applications.
Many Member States request training support, which, the IAEA organizes through a group fellowship training programme on research reactors at its headquarters and partner institutions every year. The training courses are dedicated to scientists and engineers mainly from developing countries.
"The training courses we organize offer practical exercises and experiments designed to reinforce theoretical lectures that students typically complete in their home countries," explains Mr. Bradley. "It is a hands-on course with a reactor dedicated to their use where fellows learn about reactor operation and engineering, and support activities such as radiation protection and safety culture."
The goal of these training courses is to provide a practical reinforcement of theoretical coursework so fellows can develop ideas to better utilize an already existing research reactor or support a project to develop a new reactor when returning to their home countries.
For the past two years, the IAEA Nuclear Energy Management School includes a dedicated session on Nuclear Infrastructure for R&D and Applications, where the important role of RRs and their numerous applications are presented in series of lectures.
Neutron Applications
Neutron imaging is one of the most popular applications of the neutron beams delivered by research reactors. Also known as neutron radiography, the technique uses neutron beams to determine industrial products' material properties. It is a proven technique used to efficiently measure the strength, durability or integrity of materials. Neutrons, unlike x-rays, are sensitive to light elements, like water or hydrogen. In addition, neutrons can penetrate much deeper into the matter than other probes. Therefore, neutron imaging can identify certain product properties that other techniques cannot. For example, neutron imaging can be used to depict three-dimensional images of brazing connections in various devices or accurately determine water distribution in the membranes of fuel cells.
"Neutrons have proven to be very helpful in performing elemental analysis of different samples through the neutron activation analysis," says Mr. Danas Ridikas, a Research Reactor Specialist at the IAEA Physics Section. "They can also be used as a source for radiation to improve the qualities of materials through techniques such as gem coloration and neutron transmutation doping of silicon."
Two new IAEA Coordinated Research Projects (CRP) to further assist Member States in the development of advanced neutron imaging and tomography techniques, as well as to increase their analytical capacity through neutron activation analysis automation, are about to start.
Innovation Through Coalition
Research reactors are extremely valuable training, research and technological tools, thus their continued availability must be assured.
However, a number of important challenges associated with ageing, under-utilization, fuel cycle and safety aspects, along with issues on staffing and funding continue to be a major concern in many countries. At the same time, many countries are increasingly interested in launching research reactor programmes and have approached the IAEA for assistance.
In response, the IAEA continues to support initiatives in, for example, core conversion and fuel repatriation projects, organizing meetings and workshops and encouraging collaboration through coordinated research projects. The IAEA is also encouraging Member States to be part of research reactor coalitions and networks, as a first step in developing their national capabilities. The IAEA's research reactor coalitions and networks currently engage 42 Member States, of which 25 countries operate research reactors, while 17 countries do not have such facilities.
Its well-known sibling, the nuclear power reactor assists development by energising electricity grids, but few realize that research reactors contribute as much to our daily lives by energising scientific innovation, research and medical care.
-- by Iulia Iliut and Rodolfo Quevenco, IAEA Division of Pubic Information
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