VVER-1200 Tests in No. 6 Unit of the Novovoronezh NPP During Operation in a Daily Load Schedule

The purpose of tests is experimental validation of VVER-1200 power unit operation in a daily load schedule and to work out a method of controlling and checking the operation of the equipment. A method of controlling the reactor based on the principle of localization of xenon processes in the top half of the core in combination with soft temperature control was tested. The method allows control of reactivity by changing the coolant temperature in the primary loop at the expense of steam pressure variations in an extended range in the secondary loop. The tests confirmed that VVER-1200 power units can actually operate in a daily load schedule at the end of a fuel run without actually increasing the volume of the radioactive coolant withdrawn from the primary loop.