Steady-State Hydraulic Circuits

Primary circuit thermal hydraulics was investigated at zero reactor power, both under steady-state conditions and simulated emergency conditions. All the loops of secondary circuit were filled with sodium in February 1980. The investigation showed that the hydraulic resistance of the loops was two times below the design value. Power startup began on 5 April 1980. Forty and eighthy percent as well as fuel nominal power of 1470 MW(th) [600 MW(e)] was reached in mid June, mid August and on 18 December 1980, respectively. 

This chapter deals only with established regime (steady-state) flows in a hydranhc circuit. In this framewoik, we emphasize the difference between flows in convergent and divergent pipes, discuss the effect of turbulence on pipe flows, and tackle the problem of cavitation. Transient flows in hydraulic circuits will be dealt with in Chapter 6, when discussing water hammer phenomena. 

For the cold plenum, thermal-hydraulics studies should enable the thermal stresses in the structures (in particular the main vessel and the internal vessel) to be calculated, and the correct hydraulic supply to the primary pumps to be ensured. These studies should be carried out for the various operating states of the reactor symmetrical and assymmetrical vvith a secondary circuit out of operation, and for steady state conditions as well as transients. 

The required thermal hydraulic analysis has been carried out using the one dimensional plant dynamics analysis code DYANA-P. The analysis of the instantaneous sodium coolant pipe rupture requires using two different sets of equations in the primary circuit hydraulic model for the initial steady state and subsequent transient. 

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