Effect of Modernization of the Third Generation Nuclear Reactors (Model V-446) on Nuclear Safety

A set of Nuclear Reactor model V-446 applied in design AES-91/99 is regarded as an optimized project of reactor VVER-1000 on the basis of reactor model V-320. Improving the neutron- physics characteristics of the active core along with the reconstruction of reactor basic sections made the implementation of uranium- gadolinium fuel possible. Furthermore, by taking into consideration the negative coefficients of thermal reactivity for fuel pellet, reactor power and coolant liquid, as well as by designing the supplementary control line special for beyond-design accidents and also by carrying out hydraulic tests in the system of preventing an increase in the pressure of the primary circuit and also by ensuring the concept ˝Jeakage before breakage˝ with the help of the new control systems and special trouble-shooting of primary circuit equipment, valves and lines, we have opened up a new vista which will increase the safety coefficient of new generation contrary to the old models of VVER-1000.