PURPOSE: To prevent generated gas from flowing into a reactor core part in case of a break of a heat transfer pipe, and to intend improvement of safety by integrally building an electromagnetic coolant circulation pump part into the down stream side of a heat exchanger part in a steam generator.
CONSTITUTION: A coolant sodium Na introduced to a steam generator 20 generates a steam by heat-exchanging with water in heat transfer tubes at a heat exchanger part 24, the heat exchanged Na is sucked by a pump duct 30 and returns to a nuclear reactor vessel by the function of an electromagnetic pump part 26. In very rare case of break of the heat transfer tubes, a huge amount of water and steam flows outside the tubes to cause chemical reaction with the Na and to generate a huge amount of high temperature hydrogen gas which flows into the duct 30. At that moment, the Na cooling a three-phase coil 32 and a fixed iron core 28 at the pump part 32 is removed to bring about an overheat condition and hence the copper in the coil 32 melts away to disable conduction of power thus disabling the pump parts 26. As this pump part 26 has no rotary inertia, transportation of the Na ceases immediately after the break, flowing of the great amount of the hydrogen gas into the reacor core part can be prevented.
MAEDA KIYOHIKO
HASHIMOTO HIROSHI
| JPS61794A | 1986-01-06 | |||
| JPS63193092A | 1988-08-10 | |||
| JPS5540694U | 1980-03-15 |