Reactor tests of the HIP, in general, confirmed the results of laboratory tests on the electron arc installation (EAI). The traces of interacting working medium with the surfaces of the TIP from low density graphite (LDG) were detected. Intensity of

hydrogen interaction increased with growth of temperature along gas traffic route. The fourth heating section (HS) was observed sometimes through holes in HIP. Material ablation in these HIPs made up an order of 25-50weight%. The most defective was outer range of TIP from high density graphite (HDG).

Casings from ZrC with Pq flaking forming thermal insulation in high temperature part of HRA, in general, kept the geometry though the casings have some cracks, and at dismantling they scattered on separate fragments. The carbide casings also undergo some changes. There were separate cracks and grids of cracks. The overhead part of the HIP near to the supporting exhaust knot is underwent changes also (Fig. 7.14).

Thus, the basic defects of HIP were the cracks and an area of material flushing. The last is connected, both with chemical interacting and with an erosive material removal. The most dangerous from the point of working capacity is the ablation of HIP under contact of hot working medium with bared metal casing. The structure imperfection of HIP is increased with operating time. There is great scattering between alternative technological versions of HIP preparation. More optimum materials’ composition and reliable design of HIP will be chosen in the subsequent time of NRE development.