Russian Scientists Have Come Up With A Unique Method For Evaluating The Quality Of Materials For Nuclear Power Plants
Scientists of Tomsk Polytechnic University (TPU) have proposed a new tool that has no analogs in the world for studying structural materials of nuclear reactors — the so-called accelerated atom beams, which can significantly accelerate the research of new promising materials for nuclear power for radiation resistance, the press service of TPU reported.
TPU employees presented the results of their work on Saturday at the VII International Congress "energy flows and radiation effects" (EFRE-2020) held in Tomsk.
The conditions under which the structural elements of operating nuclear reactors, including nuclear power plants, are very strict. During their life cycle, they are exposed to such intense ionizing radiation that the number of impacts that fall on the share of each atom of the crystal lattice of these elements reaches 100-200, the atoms change position, resulting in radiation damage to structural elements.
Therefore, one of the crucial problems of radiation materials science is to study and improve the stability of structural materials to such operating conditions. In other words, they should not significantly change their properties during the entire period of use in the reactor. If the radiation resistance of the reactor structural elements, especially the fuel elements, is low, their deformation and destruction may occur.
To solve this problem, scientists in various research centers around the world conduct research on materials by placing them in a neutron irradiation chamber near a nuclear reactor and tracking the appearance of significant changes. In this case, the study takes several years. Therefore, this way is not very convenient for the rapid development of new materials and technologies.
"Currently, instead of neutron irradiation, simulated irradiation with charged particle beams is used. During simulated irradiation, the same conditions are recreated as in a nuclear reactor when irradiated with a neutron beam, the same amount of radiation damage. However, the radiation load that a particular material receives in a nuclear reactor can be collected in a few hours instead of several years," said Alexander Pushkarev, one of the authors of the work, Professor of the Department of materials science of TPU.
In the practice of radiation materials science, two tools are currently used for simulated irradiation: electron beams and ion beams. However, the mechanisms of the formation of radiation defects during irradiation with charged particle beams and neutrons differ significantly. That significantly reduces the reliability of the results of the study of the radiation resistance of materials.
Polytechnic scientists have proposed a new tool — beams of accelerated atoms. They are formed using a high-power ion beam generator developed at TPU by Professor Gennady Remnev. First, a beam of accelerated ions is formed, then they are recharged, and accelerated atoms are formed. In the future, accelerated atoms with the energy of hundreds of kilo electronvolts are used to irradiate materials. According to scientists, the developed tool has no analogs in the world.
"From the point of view of radiation materials science, this is a unique tool. It differs in that it allows you to quickly dial a dose similar to the radiation dose in a nuclear reactor, and spend much less energy on the formation of defects. Besides, the mechanisms of the formation of radiation defects in metals under irradiation with accelerated atoms and neutrons are very similar. That makes it possible to increase the reliability of the performed studies of the radiation resistance of materials," Pushkarev explained.
These studies were carried out by TPU employees with colleagues from Dalian Polytechnic University (China).