|Program name||Package id||Status||Status date|
|Package ID||Orig. computer||Test computer|
PACTEL , out of pile model of VVER-440 reactor:
144 fuel rod simulators with electrically heated and chopped cosine axial power distribution (maximum power 1 MW)
three double-capacity coolant loops to simulate VVER plant with six loops
horizontally oriented secondary steam generators
pressurizer, high and low pressure core cooling systems
1/ 305 volume and power scaled model of Russian-designed PWR of the VVER-440 type
maximum power 1 MW equivalent to 22 % of scaled full power
full length fuel rod simulators
elevation of main components including loop seals preserved
diameter (overall height) of steam generators reduced
The main goal was to study natural circulation in a VVER plant including several single- and two-phase natural circulation modes. The heat generated in the core is transported by the coolant to the steam generators. The steam generator secondary side conditions were held constant, eliminating disturbances caused by the secondary pressure variation. The primary coolant mass was reduced stepwise in the liquid form, and the amount of the drained water was given as a boundary condition. The draining period is very short compared to the stabilizing period, therefore the different natural circulation mechanisms are clearly identified. It was expected that the characteristics of natural circulation at constant pressure is mostly dependent on the primary coolant inventory and the core power level.
During the whole experiment the steam generator level control was maintained. The secondary pressure was controlled by a PI controller.
The objectives were:
Study natural convection circulation in a VVER plant
series of quasi steady natural circulation periods
single phase natural convection and two-phase natural convection with continuous liquid flow
convection flow under reflux -boiler mode conditions
'double-blind' pre-test analyses; 'open' post-test analyses also processed
Two kinds of experiments were conducted varying the end of the experiment:
A- Experiments which were terminated by switching the core power off when the core temperature started to increase.
B- Experiments which were continued by reducing the secondary pressure. The core power was switched off after the core heat-up began again.
|Package ID||Status date||Status|
|CSNI0061/01||26-NOV-1998||Arrived at NEADB|
Keywords: data, loss-of-coolant accident, transients.