History of Materials Research: Six decades of operation of the IEA-R1 nuclear research reactor.


The IEA-R1, the first nuclear reactor in Brazil and the first research reactor in Latin America, completed 60 years of uninterrupted operation. This was commemorated with an international workshop on the use of research reactors. The event was held from November 28 to December 1 2017 in the city of São Paulo, in the auditorium of the Nuclear and Energy Research Institute (IPEN), located on the main campus of the University of São Paulo (USP). According to the organizers, about 300 people from different countries participated in the event.

IEA-R1 is well known in Brazil for producing radioactive isotopes that are used in medicine, industry and agriculture, partially meeting the national needs. Examples are Iodine-131, produced in IEA-R1 since 1959 and used in the diagnosis and treatment of thyroid cancer, and Samarium-153, used as a palliative tool to treat pain in bone metastases.

In addition to providing these elements to hospitals, industries and other entities, the IEA-R1 has been used, since the beginning, in research in several areas, including the Materials area. This research filed uses beams of free neutron (neutrons that were separated from the nuclei of the atoms), generated in the nucleus of the reactor through the nuclear fission process. The interaction of the neutrons with the samples provides unique information on the structure and composition of the materials.

According to Frederico Genezini and Rajendra Narain Saxena, IPEN researchers and current and former manager of the Research Reactor Center (CRPq), respectively, neutrons have a very specific feature of interacting with matter. It is possible, through scattering, to carry out studies of crystalline structures, and since the neutron has a magnetic moment, it is also used to study the magnetic properties of materials.

IEA-R1.
IEA-R1.

Located at IPEN, the reactor is formed by a 9-meter deep pool of deep blue waters. This color is originated by the so-called Cherenkov effect, in which charged particles (in this case, ions generated by nuclear fission) cross the medium (in this case, water) at a higher speed than light in that medium, emitting the flashy blue radiation. The pool water is contained by 1 to 3 meter thick walls constructed of very hard concrete. The bottom of the pool houses the reactor core, in which uranium is bombarded with neutrons, generating nuclear fission reactions. As a result, the nuclei of the uranium atoms are divided into two, while two or three neutrons and a large amount of energy are released (that very strong energy that holds the protons and neutrons together in the nucleus of the atom). While in the nuclear plants the released energy is harnessed, in the research reactors the most important product is the neutrons, the reason why the reactor components aim at preserving the free neutrons.

Water and concrete around the core perform important safety functions that prevent harmful levels of radiation from passing into the vicinity of the pool, where researchers, the team responsible for the reactor and the visitors circulate (about 2,000 people visit the IEA-R1 every year).

The process of producing uranium for IEA-R1 is completely carried out in Brazil. The ore is extracted and processed in the state of Bahia, enriched to a little less than 20% at the Navy Technological Center in Iperó (São Paulo state), and finally packed inside the “fuel elements”, which are then placed in the core of the reactor. Brazil belongs to the group of only 12 countries that can enrich uranium.

Neutrons to investigate matter

Around the pool – at the bottom, the IEA-R1 reactor has 12 experimental stations, in which neutron beams extracted from the reactor are available to be used in conjunction with several experimental techniques.

According to Genezini and Saxena, at present only three of the stations have equipment installed: the high-resolution neutron diffractometer, real-time neutron imaging systems, and the experimental system for boron neutron capture therapy (BNCT). However, other stations are available – on demand – for the installation of instruments. The first two facilities are very useful for studying materials, and have advantages over equivalent equipment that uses X-rays instead of neutrons. According to Genezini and Saxena, the diffractometer allows studying crystallographic structures of materials that an X-ray diffractometer cannot always observe, besides the study of magnetic structures.

“While X-rays interact with matter through electromagnetic forces, neutrons basically interact via nuclear forces,” explains Reynaldo Pugliesi, an IPEN researcher responsible for neutron imaging equipment, designed and built at IPEN and installed in one of the IEA-R1 stations. For example, a sample of 1 cm2 analyzed at this experimental station can receive about 8 million neutrons per second.

Neutron imaging provides, without destroying or damaging the samples, two or three dimension images (the latter called neutron tomography) of details that would otherwise be imperceptible to the human eye. In particular, hydrogen-rich materials (such as oil, water, adhesives and rubbers) are particularly well captured in neutron imaging, even when encapsulated in metals such as steel, aluminum and lead. In fact, the neutrons can penetrate several inches into the metals and reveal what’s inside them. Also in this regard, neutron imaging is complementary to X-ray imaging: while neutrons reveal light materials that are behind heavy materials (such as a crepe tape inside an aluminum frame), X-rays reveal heavy materials behind lightweight materials (such as the bones in the hand).

Neutron tomography: inspection of a restoration made in a ceramic vessel to check the degree of perfection of the work.
Neutron tomography: inspection of a restoration made in a ceramic vessel to check the degree of perfection of the work.

The IEA-R1 is open to the scientific and business community through collaborations with CRPq researchers. “In this model we have many examples of institutions and companies that have used the IEA-R1 neutron beams and other instruments in the CRPq laboratories for measurements,” says Genezini. According to him, other models are not possible because there are no technicians dedicated to each instrument. “However, this model has proven to be inefficient and we are investing in instrumentation and regulations to make neutron beam equipment more accessible to people outside the organization,” concludes the CRPq manager.

History

The origins of the IEA-R1 nuclear reactor date back to the mid-1950s, when the United States, under President Dwight Eisenhower, launched the “Atoms for Peace” program, which disseminated and encouraged worldwide the peaceful use of nuclear technology. In this context, Brazil and the United States signed agreements aimed at the discovery and research of uranium in Brazil and the development and use in Brazil of radioactive isotopes for agriculture and industry. For this, it was necessary to have a nuclear reactor in the national territory.

Thus, in August 1956, the Brazilian government decreed the creation of the Institute of Atomic Energy (IEA), which would later be called IPEN, to supervise the construction and operation of the IEA-R1. The construction was carried out by the US company The Babcock & Wilcox Company, accompanied by a Brazilian team led by the first director of the IEA-R1, the Brazilian nuclear physicist Marcelo Damy de Souza Santos, also the founder of the IEA. In August 1957, the construction of the reactor was completed and, on September 16 of that same year, the reactor reached the necessary conditions to start operating. The inauguration ceremony of the IEA-R1 was held on January 25, 1958, with the presence of President Juscelino Kubitschek and the State Governor of São Paulo Jânio Quadros.

With the IEA-R1, Brazil was able to develop national knowledge to produce nuclear fuel, neutron research instruments and radioisotopes that have been used in health, agriculture and in various industries. The reactor was also used to produce, through the neutron-induced transmutation technique, semiconductors for electronic components that were exported. In addition, it was used to train reactor operators and to conduct academic work. According to Genezini and Saxena, more than 250 doctoral theses and master’s dissertations were defended during this period in the areas of Nuclear Physics and Condensed Matter, and more than a thousand scientific articles were published in indexed journals.

In the near future…

Another chapter in the history of research reactors in Brazil is being written. The Brazilian Multipurpose Reactor (RMB), a more modern nuclear reactor with 30 MW of power (versus 5 MW of IEA-R1) is underway. In conjunction with its experimental stations, the RMB will be a national laboratory open to the community for research and for production of radioisotopes, installed on a 2 million m2 site in Iperó (SP).

According to José Augusto Perrotta, technical coordinator of RMB, the reactor is still in the design phase. The conceptual and basic projects have already been completed, and the detailed project is being executed. In addition, the IBAMA (Brazilian Institute of Environment and Renewable Natural Resources) license has been issued, as well as the site license of CNEN. However, the initial timeline was affected by problems related to financial resources. “The Ministry of Science, Technology, Innovations and Communications did not release the resources in 2017,” says Perrota. “The project continued with only the resources designated in 2014. Every year without resources is a year behind schedule!” he laments.

 

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Interviews with plenary speakers of the XV Brazil-MRS Meeting: Lei Jiang (Chinese Academy of Science, China).


By studying spider webs, fish scales, lotus leaves and cactus, the Chinese scientist Lei Jiang (Technical Institute of Physics and Chemistry – Chinese Academy of Science) and his group have developed artificial systems that can be extremely useful for human being. For example, surfaces that exhibit superphobic or superphilic properties concerning water, oil and air. Professor Jiang´s surfaces and interfaces can also be intelligent and switch from superhydrophilicity to superhydrophobicity.

Prof. Jiang will come to Brazil at the end of September to present all these discoveries, and also the concept of “binary cooperative complementary nanomaterials” (BCCNMs), in a plenary lecture of the XV Brazil-MRS Meeting.

Lei Jiang obtained a B.S. in solid-state physics in 1987 and a M.S. in physical chemistry in 1990 from Jilin University of China. Then, he embraced doctoral studies in the same university. After a period in the University of Tokyo (Japan), he obtained his Ph.D. diploma in physical chemistry from Jilin University of China. From 1994 to 1996, he was postdoctoral fellow in the Akira Fujishima‘s group at Tokyo University of Science. Then, he remained in Japan as a researcher of Kanagawa Academy of Sciences and Technology. In 1999, he joined, as a Professor, the Institute of Chemistry at CAS. From 2004 to 2006, he also served as Chief Scientist of the National Center for Nanoscience and Technology of China.

Prof. Jiang (H index=92) is author of two books, 8 review papers and book chapters, and over 500 papers including articles in Nature, Nature Nanotechnology, Nature Materials, among many other high-impact journals. He holds dozens of granted patents and patent applications. His publications have been cited more than 38,000 times.

Lei Jiang is academician of CAS since 2009, foreign member of the US National Academy of Engineering since 2016, fellow of the Royal Society of Chemistry since 2010, and fellow of The World Academy of Sciences (TWAS) since 2012. Jiang acts in the boards of scientific journals Small, Advanced Functional Materials, Advanced Materials Interfaces, NPG Asia Materials, Journal of Inorganic Biochemistry and Materials Research Innovations. He has received many awards and honors granted by Chinese entities. His contributions have also been recognized with the TWAS Chemistry Award in 2011 and the MRS Mid-Career Researcher Award in 2014.

Here follows an interview with Professor Jiang.

SBPMat newsletter: – Explain in a few words your approach to learning from nature.

Lei Jiang: – We learn from nature mainly focusing on biological interfaces with superwettability, and then we investigated the correlation between the multiscale structures and superwettability. After that we design target molecules to prepare bioinspired functional materials with promising applications, such as self-cleaning coatings, water/oil separation, water collection, and energy conversion. Finally, by combining two complementary properties and achieving reversible switching between them, we were able to develop bioinspired smart interfacial materials with superwettability.

SBPMat newsletter: – Do you and your group perform nature observation by yourselves?

Lei Jiang: – Yes, we perform nature observation by ourselves.

SBPMat newsletter: – Do you search for specific plants or animals having in mind specific applications?

Lei Jiang: – Yes, we mainly focus on specific plants or animals with superwettability.

SBPMat newsletter: – Do you work in collaboration with biologists and materials engineers from other groups to understand nature and produce the artificial materials systems?

Lei Jiang: – Yes, we always work in collaboration with other groups, who are focused on materials, mechanics, biology etc., to understand nature and produce the artificial materials systems.

SBPMat newsletter: – Are there products in the market, or almost there, based on your discoveries? How were they created (through patent licensing, spinoff companies, joint development)?

Lei Jiang: – We have transferred several research findings in the laboratory to practical products in the market. Until now, we have cofounded 3 technology companies.  As one of the very first commercially available bioinspired material produced in large scale, our superhydrophilic coatings have been applied to landmark buildings such as the China National Grand Theatre, and the Beijing International Airport. Our oil/water separation system has also been applied to more than 630 ships travelling around the world. Based on the materials with special wettability, a bioinspired green printing technology is also currently being used to print newspapers by many publishers.

SBPMat newsletter: – To those readers who may be very curious about your concept of “binary cooperative complementary nanomaterials”, please say a couple of words about it. Is there a philosophical idea behind that concept?

Lei Jiang: – Binary cooperative complementary materials, consisting of two components with entirely opposite physiochemical properties at the nanoscale, are presented as a novel principle for the design and construct of functional materials. By summarizing recent achievement in materials science, it can be found that the cooperative interaction distance between the pair of complementary properties must be comparable with the scale of related physical or chemical parameter. When the binary components are in the cooperative distance, the cooperation between these building blocks becomes dominant and endows the macroscopic materials with unique properties and advanced functionalities that cannot be achieved by either of building blocks. The law of unity and interpenetration of opposites was proposed in “Dialectics of Nature,” an unfinished 1883 work by Friedrich Engels. He stated “Everywhere we look in nature, we see the dynamic co-existence of opposing tendencies. This creative tension is what gives life and motion.” Dialectic was derived from the works of philosophers G. W. F. Hegel (1831) and Heraclitus (500 BC), who thought that everything was constantly changing and that all things consisted of two opposite elements that could change into each other. Ancient Chinese philosophers also utilized “Yin” and “Yang” as two basic polarities of the universe to interpret the binary cooperative complementary phenomenon in nature and the universe. However, Engels simply thought the idea of “Yin” and “Yang” was just an embryo of dialectics in ancient China. However, Chinese philosophers had already studied the evolution process and unity of two opposite elements quantitatively. For example, “I Ching” (1000–750 BC), an ancient Chinese book of changes, stated that 64 Yin-Yang combinations known as “64-gua” are possible with hexagrams (patterns of 6 broken and unbroken lines).

Please find the details about “binary cooperative complementary materials” in ” Science China Materials, 2016, 59, 239–246, http://link.springer.com/article/10.1007/s40843-016-5051-6 ”

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Link to the abstract of the XV Brazil-MRS Meeting plenary talk “Smart Interfacial Materials from Super-Wettability to Binary Cooperative Complementary Systems”: http://sbpmat.org.br/15encontro/speakers/abstracts/5.pdf