Methods of Modeling Tests

Model tests of the component units of HRAs are, along with calculations, the main tool for the experimental substantiation of the construction at the stage of technical project development. The tests were performed with model samples of component units under laboratory conditions. A specific feature of these studies is the separate influence of different action conditions. The complex action was estimated using the superposition principle by alternating separate tests in stages. This course of action is admissible in the case of the block HRA construction and is caused by the complexity of simulating natural operation conditions. The results obtained on high-temperature testing units allowed optimizing the design and technological solutions used in the HRA development.

At the initial period of NRE development, estimating the efficiency of the con­struction units of the NRE core was difficult because of the lack of sufficiently complete information on the physical and mechanical properties of materials, espe­cially at high temperatures. It was necessary to verify the correctness of the design and technological solutions in laboratory studies and prereactor tests. To solve these problems, a structure of the experimental equipment was created at the RIHRE, some instruments of the structure being unique. During the development of methods for testing refractory ceramic materials in a broad temperature range from 300 to 3,000K, a number of difficulties related to the specific properties of these materials were encountered.

The high hardness and high brittleness of carbides, nitrides, and other refractory materials complicating their machining exclude the option of using large samples of a complicated shape because of technological restrictions on their manufacturing. The easy oxidizability of these materials upon heating in air requires performing tests in a vacuum or inert medium and preventing the possible interaction of samples with heater materials.

For these reasons, standard setups for testing metals could not be used and it was necessary to develop or refine a structure of high-temperature setups satisfying these requirements.

A. Lanin, Nuclear Rocket Engine Reactor, Springer Series in Materials Science 170, 21

DOI: 10.1007/978-3-642-32430-7_3, © Springer-Verlag Berlin Heidelberg 2013

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Fig. 3.1 General view of a universal high-temperature installation UHTI-1 for mechanical tests up to 3,200 K in argon environment and b the scheme of a design of the heating chamber and loading device, (1 measuring compartment, 2 dynamometer, 3 bars of a sample fastening, 4, 5 graphite heater)

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