Nuclear reactor system and method for operating the same

A nuclear reactor system having a water-cooled reactor, comprising:

• reactor containment;
• a shielding pit inside said reactor containment, said shielding pit having a lower region with an outlet opening formed therein;
• a reactor pressure vessel disposed in said shielding pit;
• a moderating cell disposed downstream of said outlet opening and laterally adjacent said shielding pit, said moderating cell having a device for slowing down and diverting a melt flowing through said outlet opening;
• a catch basin downstream of said moderating cell for receiving a melt and a supply of water, said moderating cell having a bottom, and including a hollow chamber being disposed underneath said bottom of said moderating cell and being filled with water.

A nuclear reactor system having a water-cooled reactor, comprising:

• a reactor containment;
• a shielding pit inside said reactor containment, said shielding pit having a lower region with an outlet opening formed therein;
• a reactor pressure vessel disposed in said shielding pit;
• a moderating cell disposed downstream of said outlet opening and laterally adjacent said shielding pit, said moderating cell having a device for slowing down and diverting a melt flowing through said outlet opening;
• a catch basin downstream of said moderating cell for receiving a melt and a supply of water, said catch basin having a bottom, and including a continuously curved drainage channel being disposed between said moderating cell and said catch basin, for discharging at a tangent onto said bottom of said catch basin.

A method for operating a nuclear reactor system including a water-cooled reactor having a reactor containment;

• a shielding pit inside the reactor containment, the shielding pit having a lower region with an outlet opening formed therein and a bottom with a lowermost region;
• a reactor pressure vessel disposed in the shielding pit;
• a moderating cell disposed downstream of the outlet opening and horizontally adjacent the lowermost region of the shielding pit, the moderating cell having a device for slowing down and diverting a melt flowing through the outlet opening;
• and a catch basin being disposed downstream of the moderating cell and having a bottom for receiving a melt and a supply of water, which comprises:
• covering the bottom of the catch basin with water during normal operation of the reactor, and maintaining the water in the catch basin at a surface level being lower than the lowermost region of the bottom of the shielding pit.