Stefan Mehedinteanu
The Application of RCS Depressurization to Prevent Core Melting in Case of Very Small LOCA in Nuclear Reactors
A very small LOCA (in capacity of Pressure and Inventory Control (PIC) system) along of reactor coolant system (RCS)-outside core area and without operator actions to earliest and manual shutdown the reactor (not so much time for action), even all the safety systems are available, can go to a severe phase. The previous work describes a new method to prevent the core melting in the pressure tube reactors. The accident analysis using the developed model (ASQR) strengthens the importance of the inside cooling of the fuel channels in order to prevent severe accidents, despite those methods related to moderator as the last heat sink, these are not sufficient. The method concerns the use of a safety auto-depressurization of the pressurizer (ADS) by means of a new safety valve block located on the line to the degasser-condenser (DC).