Search

In this paper, we consider means to develop and improve a dc traction power supply systems and its adaptation for high-speed mine lines. One way to improve and increase the efficiency of the traction power supply system is to increase the rated voltage in the dc traction grid up to 24 kV. This allows increasing the throughput and carrying capacity of railways, increasing the distance between substations, and reducing the cross section of the traction grid wires and electricity losses in power supply devices. All this, as well as the absence of supply voltage unbalance under dc, inductive losses, and a significantly lower electromagnetic effect on the infrastructure, is more efficient than all ac traction power supply systems. We determined the directions of numerical modeling and proposed nonlinear numerical models that allow analyzing the interaction of sources of electromagnetic fields of traditional and superconducting electrical equipment under the conditions of an unlimited region of magnetic field propagation and the absence of symmetry of the field distribution in space. To determine the effect of electromagnetic fields on the integral parameters of traditional and superconducting electrical equipment, an algorithm and a package of applied programs were developed. We performed studies and substantiated the parameters and dimensions of superconducting inductive reactors of smoothing traction substation filters at which the volume of occupied space is minimized and the best use of superconducting material is ensured at a specified energy intensity.

Utilization of DC and AC HTS cable lines in electrical grid enables enhancement of the transmission capacity, reduced power losses, lowering of allotment areas, improvement of environmental conditions and improvement of fire and explosion safety of these power transmission lines. An HTS DC cable lines (CL) bring the new additional advantages, including the opportunity to introduce into the power system a new electric link without increasing fault current level. It allows to connect input stations in the city on medium voltage sites and, as a result, improves the reliability of the energy supply to customers. Federal Grid Company of Unified Energy System (FGC UES) started with the development and construction of a HTS DC cable link, which included the cable, cryogenics, AC/DC/AC converters, terminations and cable coupling joints. The link will connect two substations on downtown area. The purpose of this project is to operate at 50 MW HTS cable in the live network of St. Petersburg to demonstrate its effectiveness and improve the reliability of the grid. Nowadays are developed all the elements of the line and all technologies required for cable manufacturing. After successful tests of two 30-m HTS cable samples together with current leads and coupling boxes, full scale production of all devises for HTS DC cable line was began. This paper describes the current status of the production and tests of the HTS cable line elements.

The design of the ASTRA facility and critical assemblies that simulate physics features of modular high-temperature reactors (HTHR-Ms) with a graphite moderator and reflectors loaded with fuel particles having multilayer ceramic coatings is described in detail. Geometrical dimensions of the main elements and regions of the critical assemblies, composition of the materials used, and experimental results for various configurations of the critical assemblies are presented. A detailed computational benchmark model allowing for the structural and compositional features of the critical assembly configurations in question is developed on the basis of all the above data. The results are to be used for verification of the neutronics codes used for calculations of high-temperature helium-cooled reactors.

The “zero” power ASTRA critical facility at the Kurchatov Institute is intended for experimental investigation of neutronics of HTGR reactors. Spherical graphite elements with multilayer coated fuel particles inside, along with pure graphite and absorber containing spherical elements can be used in different configurations of cores. Reactor-grade graphite blocks are used in the structures of bottom, side, top, and/or internal reflectors. Hardware capabilities of the facility allow creation of the critical assemblies with the outer diameter and height of the side reflector of up to 3.8 and 4.6 m, respectively. The ASTRA critical facility was used to simulate the HTGR reactors earlier designed in Russia, PBMR reactor (being developed in RSA) and is going to be used under the international GT-MHR project (France, Japan, Russia, USA) mainly for the purpose of obtaining experimental benchmark data for computer code validations. Brief description of the ASTRA facility characteristics, investigated core configurations, experimental methods, and results is given in the paper.

The TOPAZ‐2 reactor system is a heterogeneous epithermal system fueled with highly‐enriched fuel based on uranium oxide, cooled by a sodium‐potassium liquid metal (NaK), using a zirconium hydride moderator, with 37 thermionic fuel elements (TFEs) built into the core. The core is surrounded by a radial beryllium reflector which contains rotating regulating drums with moderating segments. An important problem is the guaranteeing of nuclear safety upon the accidental falling of the TOPAZ‐2 reactor into water, which leads to the growth of the reactivity of the reactor. It has turned out that it is necessary to use the Monte‐Carlo method for the conduct of neutronics calculations of such a complex reactor. In the United States (U.S.) and Russia, different codes based on the Monte‐Carlo method are used for calculations — the MCNP code in the U.S., and the MCU‐2 code in Russia. The goal of this work is the comparison of the codes and neutronics data used in the U.S. and Russia for the basis of the TOPAZ‐2 nuclea...