Yu. I. Orlov

Use of lead-bismuth coolant in nuclear reactors and accelerator-driven systems

Abstract Experience of using lead-bismuth coolant in reactors of Russian nuclear submarines is briefly presented. The salient points of the concept providing the safety of reactor facilities cooled by a lead-bismuth eutectic are covered. The key results of developments for use of a lead-bismuth coolant in nuclear reactors and accelerator-driven system, are presented.

Inherently safe lead — bismuth — cooled reactors

The design of the BRUS-150 lead-bismuth alloy cooled reactor is outlined. The reactor is a two-loop system with liquid metal coolant in the first loop and a steam-water cycle in the seond loop. One design application described is for a modular, single unit reactor with an electrical output of 150 to 170 MW for multipurpose central nuclear heat and electric power plants. The reactor could also be used in nuclear power plants, special nuclear power plants for utilizing weapons and reactor plutonium, and transmutation of actinides.

Tests of models of BREST-OD-300 reactor fuel elements in an autonomous lead-cooled channel of a BOR-60 reactor

A special feature of the BREST-OD-300 reactor that is now being designed is that it employs a container-type heat-conducting fuel element with mixed uranium–plutonium mononitride fuel, a lead sublayer, and an expansion volume at the top to collect gaseous products. The fuel elements are arranged in a square array with a wide spacing and are spaced by laminated spacing lattices.The substantiation of the technical solutions adopted for the construction of the reactor fuel elements and fuel assemblies, specifically, the combined effect of the coolant and heat loads on the fuel-element cladding and the spacing lattices, led to the choice of the BOR-60 sodium-cooled fast research reactor as an experimental base and required the development and construction of an autonomous lead-cooled channel loaded into a cell through a passage in the rotatable plugs of the reactor. The channel was tested for two microruns with the BOR-60 reactor operating at 45 MW. The lead temperature at the fuel assembly entrance was 595°C, the working temperature of the cladding was ≤658°C, the damaging dose was 6.5 displacements/atom, and the fuel burnup was 0.44% h.a. Analysis of the activity of the gas and the lead showed that the fuel elements are sealed. Post-reactor studies have been conducted since August 2002.

Experimental Investigations of the Hydrodynamics of the Flow Part of Models of a Water-Based Liquid-Metal Target

The hydrodynamics of the flow part of variants of a water-based design of a liquid-metal target is investigated from the standpoint of its meeting the requirements. Investigations of the measurement of the velocity fields in the region of heat release of the liquid-metal target and also of the effect of variations of certain geometric characteristics of the target on the hydrodynamics in this region are performed. The optimal values of the individual geometric parameters of the target were determined from the results of this work and conclusions are drawn concerning whether or not the target structure meets the requirements as a whole. 5 figures.

Lead–Bismuth and Lead Coolant in a New Technology for Reprocessing Liquids and Gases

Lead–bismuth and lead coolants have special features which make it possible to regard them not only as coolants for nuclear power systems but also as the working body for obtaining valuable technological products. In this article, computational and experimental results concerning the production of hydrogen, synthesis gas, fresh water, nanomaterials, water vapor, and petroleum distillates in the processes and apparatus used for direct-contact heat transfer from liquid-metal coolants to various liquids and gases by direct mixing in the absence of intermediate solid heat-exhange surfaces are presented. The results substantiate the possibilities and prospects for developing nuclear-technological systems for the production of heat, electricity, and valuable technological products.

Thermal Experiments on a Model of a Target for an Accelerator-Driven System

The results of experiments performed on a model of a window target of an accelerator-driven system are presented. The model, the special features of the structure, and the measurement systems and methodological approaches are briefly described. A eutectic sodium–potassium alloy is used to simulate the lead–bismuth eutectic alloy. The following characteristics were measured directly in the experiments or obtained by analyzing the experimental data: coolant flow rate, power, absolute coolant temperature as a function of distance from the target membrane, the absolute temperature of the membrane surface as a function of the distance from the membrane center, the standard deviations of the indicated quantities and the pulsations of the coolant and membrane temperatures. The measurements showed that large temperature pulsations are observed on the membrane surface; these must be taken into account when analyzing the strength characteristics of a real target setup.