Yu. M. Semchenkov

Erratum to: “The concept of extending the service life of the VVER-440-based power units at the Novovoronezh Nuclear Power Plant”

Basic statements of the Concept of Extending the Service Life of the VVER-440-Based Power Units at the Novovoronezh NPP beyond 45 years are considered. This topic is raised in connection with the fact that that in December 2016 and in December 2017 the extended service lives of Units 3 and 4 at this NPP will expire. The adopted concept of repeatedly extending the service life of the Novovoronezh NPP Unit 4 implies fitting the power unit with additional reactor core cooling systems with a view to extend the (ultimate) design-basis accidents (which have hitherto been adopted to be a loss of coolant accident involving a leak of reactor coolant through a break with a nominal diameter of 100 mm) to a reactor coolant leak equivalent to rupture of the main reactor coolant pipeline. The modified Unit 4 will also use the safety systems of Unit 3 that is going to be decommissioned. Preliminary calculated assessments of the new design-basis accident scenario involving rupture of the reactor coolant pipeline in Unit 4 fitted with a new configuration of safety systems confirmed the correctness of the adopted concept of repeatedly extending the service life of Unit 4.

Problems and Prospects of New Generation Light-Water Reactors at Supercritical Pressure

Basic problems in neutron physics, structural materials of fuel rods, and assemblies (FA) for a new generation light-water reactors with supercritical parameters of coolant are considered.

Prospects for development of nuclear power stations equipped with VVER reactors

The prospects for further development in Russia of nuclear stations equipped with water-cooled water-moderated reactors are considered.

Prospects for and problems of using light-water supercritical-pressure coolant in nuclear reactors in order to increase the efficiency of the nuclear fuel cycle

Trends in the development of the power sector of the Russian and world power industries both at present time and in the near future are analyzed. Trends in the rise of prices for reserves of fossil and nuclear fuels used for electricity production are compared. An analysis of the competitiveness of electricity production at nuclear power plants as compared to the competitiveness of electricity produced at coal-fired and natural-gas-fired thermal power plants is performed. The efficiency of the open nuclear fuel cycle and various versions of the closed nuclear fuel cycle is discussed. The requirements on light-water reactors under the scenario of dynamic development of the nuclear power industry in Russia are determined. Results of analyzing the efficiency of fuel utilization for various versions of vessel-type light-water reactors with supercritical coolant are given. Advantages and problems of reactors with supercritical-pressure water are listed.

Increasing the rated capacity of power units installed at Russian nuclear power stations equipped with VVER-1000 reactors

Safe operation of the Balakovo nuclear power station’s Unit 2 built around a VVER-1000 reactor at a thermal power output of 3120 MW with meeting of the safety criteria and compliance with the requirements of existing regulatory documents is substantiated. Results from measurements of process parameters at a power output equal to 104% of its nominal value are presented.

Measurement of the Absolute Power of a Fuel Assembly and Current by Direct-Charge Detectors on a SK-fiz Critical Test Stand

A series of investigations studying the currents of rhodium sensors in in-reactor monitoring systems and the relation between the currents and the energy release in the fuel elements in the nearest neighbor environment in a VVÉR-1000 fuel assembly model was completed in 2001–2002 at the Russsian Science Center Kurchatov Institute. The experiments were performed on the SK-fiz critical test stand; the calculations were performed using the high precision MCU-REA/2 computer program, implementing the Monte Carlo method. The reference experimental-computational method for determining the relation between the DCD current and the number of fissions in the six neighboring fuel elements and fuel assembly is described, the effects due to the arrangement of the DCDs at the center and in the fourth row of the fuel assembly are studied, and the experimental data are compared with the computational results.The possibilities of the only high-flux critical test stand in the industry are demonstrated (the thermal-neutron flux density 1011 sec–1·cm–2, high accuracy of the experimental and computational methods). The SK-fiz stand and the high precision MCU-REA/2 computer program make it possible to perform comprehensive and detailed investigations of the relationship between the DCD current and the local and integral energy release in fuel assemblies.