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Shekhanova M.E.,RAS Nuclear Safety Institute
Journal of Physics: Conference Series | Year: 2017

In this paper we propose a method of using neutronic calculation code CORNER to the analysis of experiments on the protection of fast neutron reactor and CNFC equipment. An example of Winfrith Graphite Benchmark experiment calculation using this approach is presented. This task can be considered as one step in the general theme of the safety analysis of FR with liquid metal coolant, their fuel cycles and related equipment. CORNER implement a solution of the kinetic equation with a source in the three-dimensional hexagonal geometry based on Sn-method. The purpose of this paper is a demonstration of the application of CORNER's possibilities for the analysis of the actual reactor problems. © Published under licence by IOP Publishing Ltd.


Puetzfeld D.,University of Bremen | Obukhov Y.N.,RAS Nuclear Safety Institute
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We present a covariant derivation of the equations of motion for test bodies for a wide class of gravitational theories with nonminimal coupling, encompassing a general interaction via the complete set of nine parity-even curvature invariants. The equations of motion for spinning test bodies in such theories are explicitly derived by means of Synge's expansion technique. Our findings generalize previous results in the literature and allow for a direct comparison to the general relativistic equations of motion of pole-dipole test bodies. © 2013 American Physical Society.


Puetzfeld D.,University of Bremen | Obukhov Y.N.,RAS Nuclear Safety Institute
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We derive multipolar equations of motion for gravitational theories with general nonminimal coupling in spacetimes admitting torsion. Our very general findings allow for the systematic testing of whole classes of theories by means of extended test bodies. One peculiar feature of certain subclasses of nonminimal theories turns out to be their sensitivity to post-Riemannian spacetime structures even in experiments without microstructured test matter. © 2013 American Physical Society.


Obukhov Y.N.,RAS Nuclear Safety Institute | Puetzfeld D.,University of Bremen
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We use the Lagrange-Noether methods to derive the conservation laws for models in which matter interacts nonminimally with the gravitational field. The nonminimal coupling function can depend arbitrarily on the gravitational field strength. The obtained result generalizes earlier findings. The generalized conservation laws provide the basis for the derivation of the equations of motion for the nonminimally coupled test bodies. © 2013 American Physical Society.


Obukhov Y.N.,RAS Nuclear Safety Institute | Puetzfeld D.,University of Bremen
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We study general metric-affine theories of gravity in which the metric and connection are the two independent fundamental variables. In this framework, we use Lagrange-Noether methods to derive the identities and the conservation laws that correspond to the invariance of the action under general coordinate transformations. The results obtained are applied to generalized models with nonminimal coupling of matter and gravity, with a coupling function that depends arbitrarily on the covariant gravitational field variables. © 2014 American Physical Society.


Obukhov Y.N.,RAS Nuclear Safety Institute | Silenko A.J.,National Research Nuclear University MEPhI | Teryaev O.V.,Institute for Nuclear Problems
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We discuss the quantum dynamics of a Dirac fermion particle in the Poincaré gauge gravitational field. The minimal as well as the Pauli-type nonminimal coupling of a fermion with external fields is studied, bringing into consideration the notions of the translational and the Lorentz gravitational moments. The anomalous gravitomagnetic and gravitoelectric moments are ruled out on the basis of the covariance arguments. We derive the general Foldy-Wouthuysen transformation for an arbitrary configuration of the Poincaré gauge gravitational field without assuming it is weak. Making use of the Foldy-Wouthuysen Hamiltonian for the Dirac particle coupled to a magnetic field in a noninertial reference system, we analyze the recent experimental data and obtain bounds on the spacetime torsion. © 2014 American Physical Society.


Burinskii A.,RAS Nuclear Safety Institute
Gravitation and Cosmology | Year: 2015

The gravitational and electromagnetic (EM) fields of the Dirac electron are described by the Kerr-Newman (KN) solution. We elaborate a regular source of the KN solution which satisfies the requirement of flat space-time inside the source and realization of the exact KN solution outside the source. This requirement removes the conflict between gravity and quantum theory and determines many details of the source structure. In particular, we obtain that the KN source should forms a gravitating bag model, similar to the known MIT and SLAC bag models. As opposed to the known bag models, the self-interacting Higgs field should be confined inside the bag, while outside the bag the gauge symmetry should be unbroken to provide the external KN gravity. We show that the twistorial structure of the Kerr geometry (the Kerr theorem) determines the Dirac equation structure, resulting in a variable mass term which is generated inside the bag through interaction with the confined Higgs field. Similarly to the other bag models, ellipsoidal deformations of the KN bag creates a string-like structure of the dressed electron—a circular string located along the perimeter of the KN bag. © 2015, Pleiades Publishing, Ltd.


Burinskii A.,RAS Nuclear Safety Institute
Journal of Experimental and Theoretical Physics | Year: 2015

The Kerr–Newman (KN) black hole (BH) solution exhibits the external gravitational and electromagnetic field corresponding to that of the Dirac electron. For the large spin/mass ratio, a ≫ m, the BH loses horizons and acquires a naked singular ring creating two-sheeted topology. This space is regularized by the Higgs mechanism of symmetry breaking, leading to an extended particle that has a regular spinning core compatible with the external KN solution. We show that this core has much in common with the known MIT and SLAC bag models, but has the important advantage of being in accordance with the external gravitational and electromagnetic fields of the KN solution. A peculiar two-sheeted structure of Kerr’s gravity provides a framework for the implementation of the Higgs mechanism of symmetry breaking in configuration space in accordance with the concept of the electroweak sector of the Standard Model. Similar to other bag models, the KN bag is flexible and pliant to deformations. For parameters of a spinning electron, the bag takes the shape of a thin rotating disk of the Compton radius, with a ring–string structure and a quark-like singular pole formed at the sharp edge of this disk, indicating that the considered lepton bag forms a single bag–string–quark system. © 2015, Pleiades Publishing, Inc.


Ozrin V.D.,RAS Nuclear Safety Institute
Journal of Nuclear Materials | Year: 2011

A model for radial redistribution of oxygen in irradiated UO2 fuel under conditions of temperature and fission rate gradients has been developed. The oxygen transport in irradiated fuel is considered as a two-scale problem. On the local scale defined by the grain size, irradiated fuel is considered as a multi-phase system including solid solution of fission products in UO2 matrix, solid precipitates (metal phase, grey phase of complex ternary compounds, the phase of condensed CsI) formed at the gas/solid interface and the gas phase in the intergranular bubbles. Intraganular transport of fission products is described by a set of diffusion equations which are supplemented by the condition of partial thermochemical equilibrium in the subsystem "precipitates & gas phase". The boundary conditions are formulated basing on thermochemical equilibrium on the interface of subsystems "solid solution" and "precipitates & gas phase". Calculation of the partial thermochemical equilibrium yields local values of the oxygen chemical potential and the deviation from fuel stoichiometry. On the global scale defined by the fuel pellet size, spatial variations of the oxygen potential caused by the temperature gradients or the presence of sources/sinks at the pellet boundary determine thermal diffusion fluxes resulting in redistribution of oxygen. The whole set of equations describing local equilibration and the transport in the local and global scales is solved in a self-consistent manner. The model results for radial distribution of oxygen potential of UO2 calculated for typical reactor operating conditions and the fuel burnup up ∼100 MW d/kg HM are in satisfactory agreement with experimental data. © 2011 Elsevier B.V. All rights reserved.


Burinskii A.Y.,RAS Nuclear Safety Institute
Theoretical and Mathematical Physics | Year: 2013

The four-dimensional Kerr-Schild geometry contains two stringy structures. The first is the closed string formed by the Kerr singular ring, and the second is an open complex string obtained in the complex structure of the Kerr-Schild geometry. The real and complex Kerr strings together form a membrane source of the over-rotating Kerr-Newman solution without a horizon, a = J/m ≫ m. It was also recently found that the principal null congruence of the Kerr geometry is determined by the Kerr theorem as a quartic in the projective twistor space, which corresponds to an embedding of the Calabi-Yau twofold into the bulk of the Kerr geometry. We describe this embedding in detail and show that the four sheets of the twistorial K3 surface represent an analytic extension of the Kerr congruence created by antipodal involution. © 2013 Pleiades Publishing, Ltd.

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