Authors & Affiliations

Loshchinin M.V., Pometico R.S., Selivanov Yu.F., Smirnov A.M.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Loshchinin V.M. - head of laboratory, A.I. Leypunsky Institute for Physics and Power Engineering. Contacts: 1, sq. Bondarenko, Obninsk, Kaluga reg., Russia, 249033. Tel.: (484)399-48-69, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Pometico R.S. – leading researcher, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering.
Selivanov Yu.F. – leading researcher, Cand. Sci. (Tech.), A.I. Leypunsky Institute for Physics and Power Engineering.
Smirnov A.M. – senior researcher, Department of safety of nuclear powerplants, A.I. Leypunsky Institute for Physics and Power Engineering.

Abstract

Present work involves development of methods for increasing the critical power of reactor – reactor plant VVER-1200 in the occurrence of the phenomenon of a sharp deterioration in the heat transfer characteristics of a heat carrier (heat transfer crisis). Increase critical power of reactor has two objectives. First – increase operational nuclear capacity and parameters of the coolant, due to the requirements of improving economic performance of nuclear power plants.In this case it is necessary to preserve the stock power until burnout. The second goal also is to increase the safety of nuclear installations. Raising the level of critical power allowsone to avoid the overheating of fuel rods at uncontrolled surge capacity associated with failuresin the system of CPS and other reasons. Among the many ways of increasing the critical power (the use of supercritical parameters of the coolant, coolants with a high boiling point, etc.) for the VVER-1200 is the most suitable using a variety of devices, which would intensify the heat and stirred the coolant, so-called mixing grids (lattices-intensifiers) with the properties of the spacing of the fuel elements or without them.

In the present work results of researches of influence on the heat transfer crisis type, amount and location of placement in the fuel Assembly mixing grids. In particular the use of the grid, recruited from profiled cell elements. The results using grids “cyclone”, “whirlwind” and “run” (design protection), a name which reflects the type of influence of grids on the flow of coolant. In the experiments with freon and water using lattices, “cyclone” was proven a complete failure as intensifiers of heat exchange. Therefore, the bulk of the research was todetermine the effectiveness of effect on the critical power of individual FA in grids “vortex”.

In experiments it was obtained that the presenceof mixing grids led taking into account all the experimental regimes used to increase the critical power on average by about 8 – 10 %.

Keywords
water cooled reactors, experimental study, model of subassembly, water, freon, crisis of heat exchange, mixing grids, heat transfer, lattice type “vortex” and “driving, placement of gratings, efficiency

Article Text (PDF, in Russian)

References

UDC 621.039.548:621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2016, issue 5, 5:5