Abstracts and Available Papers Presented at the
2004 International RERTR Meeting

PREDICTION OF FLOW INSTABILITY DURING NATURAL CONVECTION

Kazem Farhadi
Head of Tehran Research Reactor Research Group
Nuclear Research Center
Atomic Energy Organization of Iran (AEOI) Tehran, Iran

ABSTRACT
 

The occurrence of flow excursion instability during passive heat removal for Tehran Research Reactor (TRR) has been analyzed at low-pressure and low-mass rate of flow conditions without boiling taking place. Pressure drop-flow rate characteristics in the general case are determined upon a developed code for this purpose. The code takes into account variations of different pressure drop components caused by different powers as well as different core inlet temperatures. The analysis revealed the fact that the instability can actually occur in the natural convection mode for a range of powers per fuel plates at a predetermined inlet temperature with fixed geometry of the core. Low mass rate of flow and high sub-cooling are the two important conditions for the occurrence of static instability in the TRR. The calculated results are compared with the existing data in the literature.

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