Calculation of hydraulic non-uniformity in a reactor annular cavity

A Technique has been suggested for approximated calculation of hydraulic non-uniformity of coolant distribution at the inlet portion of the WWER reactor cooling system. Azimuthal hydraulic non-uniformity at the manifold inlet caused by the effect of coolant supply through pipes, is determined. The problem is solved in the approximated analytical approach and also numerically by solving the Navier-Stokes type equations. It is shown that at the outlet of slot channels into a free volume of the manifold a certain increase in hydraulic non-uniformity (jet inversion phenomenon) should be observed. A conclusion on satisfactory agreement of the results obtained with the experimental data is made