29th Symposium of AER on VVER Reactor Physics and Reactor Safety (2019, Energoland, Mochovce NPP, Slovakia)
reactor dynamics and safety analysis
New method of maneuvering for WWER and PWR has been patented (RU 2 675 380 C1 from May 15, 2018 year). It is based on regulation of coolant flow-rate through the reactor, as a new effective and safe means of impact on reactivity. In particular, changing the flow-rate while maintaining a constant value of heating of the coolant in the reactor provides the big part of the required power change. This leads to many favorable results, which have the novelty signs, and advantages over the known maneuvering methods: prevents the occurrence of axial xenon oscillations during maneuvering, provides the most often demanded maneuvering graphs (including primary and secondary frequency control) without the control rods movement and without changing of the boron concentration in the coolant, provides reduced jumps in temperature and pressure in the primary and secondary circles, and reduced jumps of power in the fuel, as well as a number of additional technical and economic advantages. The new technology is justified by calculations using the BIPR-7 reactor code. The correctness of the obtained principal results and conclusions is confirmed by test calculations using the independent system coupled code KORSAR (3D neutron kinetics + Thermo-hydraulics).