Belt and braces

摘要

In a boiling water reactor (BWR), the water recirculation system comprises two recirculation pumps located outside the reactor pressure vessel (RPV) and a series of jet pumps inside the RPV. The system allows the operator to vary coolant flow through the core and change reactor power. In GE BWR-3 to BWR-6 designs, a ring of 16 to 24 water-jet pumps encircle the reactor vessel. The jet pumps are located in the region between the core shroud and the vessel wall, submerged in water.