Approaches to the system of radioactive waste classification in the USA and the Russian Federation were considered. The variety of sources of radioactive waste generation is shown. The necessity of radio-active waste classification and characterization is justified. The main problems in the fieldì of radioactive waste management in two countries are outlined, the ways of development of two systems to improve the activity of radioactive waste management are presented.  The basic principles of assessing the sustainability in the field of radioactive waste management INPRO and reducing the potential exposure of personnel and population of ALARA are shown. Comparisons of two national systems of radioactive waste classification were made and compliance with the IAEA recommendations was assessed.

The thermophysical properties of the main combustion products of organic substances N₂, O₂, CO₂ , H₂ are calculated by the equation of state on the basis of perturbation theory under normal conditions and in the area of high pressures. The method of calculating the viscosity of individual substances based on the Chapman − Enskog equation using the values of the radial distribution function is analyzed.

A model of a quantum-mechanical system organized by the principle of a neural network is considered. The role of neurons is played by quantum particles evolving under the action of an external doublewell potential. The instanton acts as a spike. The connection between neurons is provided by the interaction potential . The connection is directional due to asymmetry of the interaction potential. Thus, the complete Hamiltonian of the system is . The system is investigated by PIMC metod. It is shown that with a certain choice of parameters in this system, the transfer of activity in long chains of neurons is possible.

A study of thorium atoms implanted in silicon oxide was carried out usimg the density functional theory method. The charge properties of Th in the ThO₂:nSiO₂ and Th:nSiO₂ compounds, where Th acts as an interstitial and substitutional impurity in cristobalite, have been studied. Geometric optimization of structures is carried out with allowance for electron-electron  interactions, self-consistent distribution of electron density is investigated, and Bader effective charges are estimated.

In this paper, we report the characteristics of the generated beams, the extracted electron beam and the beam of secondary electrons/positrons, of the LPI accelerator complex Pakhra as of November 2019 for testing and calibrating detectors used in large accelerator and astrophysical experiments. At energies of 250– 500 MeV of the electron beam ejected into Hall 1 from the S-25R synchrotron, its energy resolution is δ ~ 1% and the intensity can be changed by collimators in the range of 10³ –10¹⁰ s⁻¹ . The quasi-monochromatic beam of secondary electrons produced in Hall 2 typically has an energy in the range of 50–300 MeV, a corresponding energy resolution of δ = 14–2%, and an intensity of ~ 10² s⁻¹ . The performed simulation of the characteristics of the secondary positron beam allowed selecting the optimal geometry of the setup and showed good agreement with the experimental data obtained later.

A variant of the protons beam delivery system with an energy of 60 MeV for the future oncoophthalmological center for proton radiation therapy at the isochronous cyclotron C-80 at PNPI was designed. The requirements to the beam characteristics were defined. Based on a series of calculations, the optimal parameters and composition of the beam line elemenós are determined. It is shown that such a beam line allows one to alternately and efficiently switch from the isotope production mode on the cyclotron to the mode of operation of the center of proton radiation therapy without a fundamental overhaul of the accelerator systems.

Production of long-lived charged particles (LLCP) with the masses of the order of 100 GeV in ultraperipheral collisions (UPC) of protons or heavy ions  at the Large Hadron Collider (LHC) is considered. A new approach for the search of such particles utilizing forward detectors of the ATLAS and CMS collaborations is proposed. Achievable bounds on the masses and lifetimes of the LLCP are estimated from the currently available LHC data.

The charge-exchange reaction  π^-p→nω(783)φ(1020), ω→ π⁺ π^- π⁰ ,  φ→K⁺K^- is studied on the upgraded VES facility (U-70, Protvino). There  are 905 events of ωφ - -system selected. The signal near  threshold  (M ~1.9 GeV/c² ) is observed in ωφ invariant mass. The five-particles partial wave analyses shows that (J^ps = 0⁺⁺) state dominates. Under the assumption of the resonant nature of the signal, its mass and width are obtained:  M  = 1814 ± 31 MeV/c²,  Г=182 ± 19 MeV/c².

Nowadays, graphene physics is aimed at finding a way to control the band gap of graphene, which is necessary for application of graphene in nanoelectronics. The purpose of this work is to investigate the systems that break an inversion symmetry of a hexagonal lattice. The electronic properties of armchair and zigzag graphene nanoribbons are obtained and the dependence  of the electronic properties on the edge effects is shown.