The Moskovsky Komsomolets newspaper published a large article about the tests of the muon tomograph at the Kalinin NPP. This tomograph was developed at the NEVOD Scientific and Educational Center of MEPhI in cooperation with colleagues from VNIIAES and the Institute of High Energy Physics. Below is the full text of the article.
One of the most technologically advanced nuclear power plants in Russia, the Kalinin NPP, is located on the territory of the Tver region. The station is firmly established in the list of leaders in electricity production. In addition, Russian nuclear scientists are moving science forward, helping in the development and implementation of high import-independent technologies.
Today we will talk about the muon tomograph, which is undergoing the final stage of research at the Kalinin NPP. This is a unique domestic development created by specialists of the MEPhI in cooperation with JSC VNIIAES (part of the management circuit of the Rosenergoatom concern). It allows to conduct a complete and accurate remote inspection of a nuclear reactor. I
In the future, this technology will improve the safety of large industrial facilities, including those not related to nuclear energy. To understand the principles of its operation, you will need a small educational course in physics. The muon is a subatomic particle. The muon flux gets to us absolutely for free, it arises in the upper atmosphere of our planet under the influence of cosmic radiation. Therefore, the technology used by atomic scientists does not require artificial sources of muons, the main thing is to track the trajectory of each particle in real time through the thickness of the material. "The method is based on capturing the muon flux passing through the object and obtaining a "picture" of the object's internal structure resembling an X-ray image.Muons have a high penetrating power. Several “pictures” from different angles allow us to assemble a three-dimensional image of the object," explains Sergey Kiselyov, Deputy Head of the Department of Nuclear Safety and Reliability of the Kalinin NPP.
The principle of studying materials by means of muon tomography (MT) is already known to the world scientific community, for example, MT was used to assess the condition of emergency reactors at the Fukushima nuclear power plant. The tecnology developed by MEPhI is peculiar because, firstly, it is completely domestic and does not depend on the supply of imported components, and secondly, it is the world's first mobile muon tomography instrument with such high spatial and temporal resolution - detection of a 20 centimeters only defect measuring is possible at a distance of more than 60 meters. In other words, at the moment it is the most accurate mobile MT installation in the world.
A muon tomograph prototype was installed near the reactor compartment of power unit No. 4 of the Kalinin NPP. This is a fairly large device that is mounted on a two-axle trailer chassis with a hydraulic lift, it looks like 3x3 square meters of "frames" located one after another with a sensitive coating. As for the technological filling, these are two complementary recording systems: a scintillation detector and a drift tube detector. Each detector has certain advantages, and together they form a unique system that allows real-time recording with high accuracy (about 0.1 degrees) all muon tracks arriving within the tomograph aperture.
The large sensitive area compensates for the relatively weak natural muon flux (only 100 particles per 1 square meter per second) and provides a high rate of statistics collection. In a stationary position, the tomograph can perform 2D muonography. If you perform muonography of the same object from several points, you can get a three-dimensional image. At the current stage, tomography technology is being developed at the Kalinin NPP, recording systems and software are being optimized.
The successful completion of the study will allow us to move to the industrial production of a line of muon tomographs. In addition to nuclear facilities, muon tomographs, which prototype is being tested at the Kalinin NPP, can be used for surveys of volcanoes, buildings, bridges, dams, cooling towers, bulky transport cargo, etc. But their main task, of course, is to improve the safety and reliability of the equipment of the nuclear energy complex. In previous publications, we told you that the nuclear power plant is constantly being modernized, working and controlling systems are being systematically replaced with more and more advanced ones.
This work is carried out by a special unit, which employs dozens of highly qualified specialists. The use of MT will be another, and very important, step on this path, moreover, it will advance the entire Russian science.
