A. V. Beznosov

Tribology of hydrostatic bearings of coolant pumps of fast neutron reactors with lead coolant

The paper describes the results of developing substantiated designs of hydrostatic bearings for coolant pumps of new-model fast neutron reactors with lead coolant. Analytical assessments of the properties of the high-temperature (450–550°C) lead coolant, which affect the serviceability of sliding bearings of submerged pumps of reactor circuits, are made. The choice of the hydrostatic bearing as the basic variant in the BREST-300 reactor is shown to be well founded. Experimental and calculation-theoretical studies are carried out for water and liquid heavy metal coolants to determine hydrodynamic and other characteristics of various members of the hydrostatic bearing. The results of the full-scale experiment are compared with the data calculated by the known methods. Two basic optimal variants of the design of the hydrostatic bearing are studied experimentally in water and high-temperature lead melt. The results of the experimental and calculation-theoretical studies are used to refine the available method for the calculation of hydrostatic bearings and develop recommendations for the optimal design schemes of such bearings as applied to conditions of reactors with the lead coolant.

Investigation of friction units of nuclear plants operating in heavy high-temperature liquid-metal heat carriers. Part 2. Experimental results

The tribological problems posed by heavy liquid-metal heat carriers used in the circuits of nuclear power plants are discussed. The results of experimental study of the vibrational wear of heat-exchanging tubes in the interfaces with the spacing grates are presented. These results are applicable for testing the vibrational strength of the steam generator of a fast neutron reactor with lead heat carrier. Experimental investigation and service-life tests of involute-profile cylindrical tooth gears and sliding bearings working in fast neutron reactors containing the lead heat carrier are conducted. Experimental and theoretical study is performed on the wear of steel and cast-iron sliding bearings in the recycling pumps of reactors operating in lead, eutectic lead-bismuth and lead-lithium alloys. It is shown experimentally that the tooth gears from 40X13 steel and SCh20 grey iron are capable of operating in the lead heat carrier for 500 and 400 hours, respectively, at the temperature 450°C when the concentration of thermodynamically active oxygen in the lead is close to saturation, the contact stress in the gearing is 758 MPa, the gear rotational frequency is 500 min−1 or less, and the gear ratio is 1.5 (the peripheral velocity of the gear and the wheel over the pitchline is 2.1 m/s). The likely causes of destruction of the gear teeth are adhesive wear and insufficient heat resistance (refractorability) of the tooth material at 450–500°C.

Friction in the annular gaps between the control rods and housing of the BREST reactor

Friction and wear between the casing of the control rod and the reactor housing with cyclic rod motion and circulation of high-temperature molten lead in the annular gap.

Friction in high-temperature lead coolant

The behavior of a frictional pair in high-temperature lead coolant during reciprocating longitudinal motion is considered. The frictional coefficient is determined as a function of the path traveled by the samples.

Study of characteristics of structures of flow and bearings for the main circulation pumps of fast neutron reactors cooled lead cooled

Results of experimental and calculation-theoretical studies aimed at substantiating a design of the flow part and hydrostatic sliding bearings of circulation pumps of reactors with a lead coolant are presented.

Contact friction in lead and lead-bismuth coolants

Analytical and experimental data are presented for the tribological characteristics of contact pairs in heavy-metal liquid coolant.

Wear of frictional surfaces in high-temperature lead and lead—bismuth coolants

The wear of frictional steel and cast-iron surfaces in high-temperature (400–550°C) liquid-metal coolants in BREST and SVBR nuclear-power units is studied experimentally. It is shown that long life of the surfaces in reactor operation may be ensured by applying and maintaining protective oxide coatings.

Vibrational wear of pipe-spacer pair in steam generator with lead coolant

The vibrational wear at the junctions of heat-exchanger pipe and spacer grids is studied experimentally, so as to confirm the shock resistance of hot-water generators in fast reactors with lead coolant. Endurance tests of tube and spacer samples are conducted. Metallographic and profilometric data on samples subjected to vibrational wear are presented. The wear mechanism is described. A preliminary estimate is obtained for the pipe life in the steam generator.

Wear of the pipe-spacing grating pair of a steam generator in a lead heat carrier

The results of the solution of tribological problems emerging when friction units operate in heavy liquid metals as heat carriers in nuclear power plants are presented. An installation has been developed to simulate the vibrational wear of friction units in heat exchanging tubes of interfaced units with spacing gratings in order to simulate resistance to the vibration of the steam generator of a fast neutron reactor with lead heat carriers. A method of study has been developed, samples of tubes and spacing gratings have been tested for vibrational wear, and metallographic and profilometric exploration has been performed. The wear mechanism is described and the tentative life of the steam generator pipes is assessed.

Investigation of nuclear-reactor friction units operating in heavy high-temperature liquid-metal heat carriers. Part 1. Experimental equipment

Experimental equipment designed for solving tribological problems arising in friction units operating in heavy liquid-metal heat carriers for nuclear-reactor circuits is discussed. In order to study fretting corrosion, a setup has been produced that simulates the wear of a fuel element in contact with a spacer grid cell. Thus, the vibration strength of the steam generator of a fast-neutron reactor with a lead heat carrier is substantiated. An experimental setup for studying and carrying out endurance testing of cylindrical gears with standard circuit and plain bearings operating in fast-neutron reactors in the medium of a lead heat carrier is described. Experimental specimens of circulation pumps for reactor equipment are developed for investigation of the wear of steel and cast-iron plain bearings operating in lead medium and the wear of eutectic lead-bismuth and lead-lithium alloys.