| 摘要 |
PURPOSE:To improve the thermal efficiency of a nuclear reactor and the safety of the reactor and to reduce the size of the construction over the entire part of the reactor by disposing a heat exchanger for a primary cooling system in a riser for conducting primary cooling water and providing a heat retaining wall around the riser. CONSTITUTION:A reactor core 3 and the heat exchanger 23 for the primary cooling system thereof are provided in the pool water of the boric acid water in a reactor pressure vessel 21 and the reactor power is controlled by adjusting the concn. of the boric acid water which is the primary cooling water. The heat exchanger 23 is disposed in the riser for guiding the primary cooling water heated in the core 3. The heat retaining wall 24 which isolates the descending flow of the primary cooling water after the heat exchange with the heat exchanger 23 is provided around the riser 6. The primary cooling water heated in the core 3 is thereby sent at a short distance to the heat exchanger 23 by which the water is subjected to the heat exchange; in addition, the direct contact of the riser 6 and the heat exchanger 23 with the pool water is obviated. Since the primary cooling water lowered in temp. by the heat exchange is guided to the heat retaining wall 24, the quantity of the heat radiation to the pool water is decreased. |
