METHODS FOR AT ACHIEVING MORE EFFICIENT PERFORMANCE OF FUEL ASSEMBLIES

Authors & Affiliations

Boltenko E.A.
Electrogorsk Research Center for Safety of Nuclear Power Plants, Electrogorsk, Russia

Boltenko E.A. - Senior Researcher, Dr. Sci. (Tech.), Electrogorsk Research Center for Safety of Nuclear Power Plants. Contacts: 6, Saint Constantine st., Electrogorsk, Moscow region, Russia, 142530. Tel.: (496)433-21-17, (916)233-12-11; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..

Abstract

More efficient operation of reactor plant fuel assemblies can be achieved through the use of new technical solution aimed obtaining more intense heat removal on conves heat-transfer surfaces, and higher values of departure from nucleater boiling ratio (DNBR). Technical solutions using which it is possible to obtain more intense heat removal on convex heat-transfer surfaces and higher DNBR values in reactor plant fuel assemblies are considered. One possible way in which more intense heat removal from a convex heat transfer surface can be obtained is to use interacting swirl flows. Enhancement of heat transfer on the convex heat-transfer surfaceis achieved owing to interaction between the swirled and transit flows.

The use of interacting swirled flows (swirl flow and transit flow) for enhancing heat transfer on a convex heat-transfer surface of fuel rods makes it possible to achieve significantly better heat removal in the convective region (by a factor of 2-3 as compared with a smooth surface. The CHF values in the entire region of two-phase flow are higher than the CHF values for a smooth surface (from 30% in the surface boiling region to 250% in the region of dispersed annular flow mode). By implementing an alternative heat removal arrangement in FAS in which heat is removed from both convex and concave heat heat-transfer surfaces of fuel rods, it is possible to obtain a significally lower maximal fuel rod temperature (by more than 1000 C with the reactor plant power output increased to 150%), significally higher power density in the reacto r plant, and much higher DNBR values on the concave and convex heat–transfer surfaces of fuel.

Keywords
fuel assembly, heat removal intensity, heat removal enhancement methods, convex surface, burn-out, critical heat flux

Article Text (PDF, in Russian)

References

UDC 536.24

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2016, issue 3, 3:3