PROBLEM TO BE SOLVED: To provide a nuclear reactor containment vessel capable of reducing a chemical concentration difference in pool water without using a power supply.SOLUTION: A nuclear reactor containment vessel 2 has a dry well 2A and suppression chambers 4 each connected to the dry well 2A via a bent pipe 5. Each suppression chamber 4 is provided with a chemical inlet 7 for inputting chemicals into pool water 6 in the suppression chamber 4. A heat transfer member 10 is disposed within each suppression chamber 4 for transferring heat between the pool water 6 located in an upper portion and chemical water 8 which is located in a lower portion and which is obtained by dissolving the chemicals in the pool water 6. The heat transfer member 10 transfers the heat of the pool water 6 in the upper portion to the chemical water 8 in the lower portion and causes heat convection within the suppression chamber 4, thereby accelerating making chemical concentrations uniform.SELECTED DRAWING: Figure 1
