Patent Number: 
Section: claims

1. A high temperature gas cooled reactor steam generation system comprising:a nuclear reactor that has helium gas as a primary coolant and heats the primary coolant by heat generated by a nuclear reaction that decelerates neutrons by a graphite block;a steam generator that has water as a secondary coolant and heats the secondary coolant by the primary coolant via the nuclear reactor to generate steam;a primary coolant discharging unit that circulates the primary coolant between the nuclear reactor and the steam generator;a steam turbine that is operated by the steam from the steam generator; a generator that generates electricity according to an operation of the steam turbine;pressure control means including a pressure difference calculation unit that includes a primary coolant pressure detection unit disposed at an inlet of the primary coolant discharging unit and configured to detect a pressure of the primary coolant and a secondary coolant pressure detection unit disposed at an outlet of the steam generator and configured to detect a pressure of the secondary coolant and to calculate a pressure difference between the primary coolant and the secondary coolant based on the detected pressures; andpressure adjustment means including a primary coolant storage unit configured to store the helium gas therein and configured to set a pressure of the secondary coolant in the steam generator to be lower than a pressure of the primary coolant in the nuclear reactor based on the pressure difference and a primary coolant recovery and supply setting unit configured to control the primary coolant storage unit to recover or supply the primary coolant based on the pressure difference calculated in the pressure difference calculation unit. 2. The high temperature gas cooled reactor steam generation system according to claim 1, wherein the pressure adjustment means includes a secondary coolant discharging unit including a feed water pump configured to discharge the secondary coolant to the steam generator, and to decrease a discharging amount of the secondary coolant in the secondary coolant discharging unit by decreasing a rotation speed of the feed water pump based on the pressure difference between the primary coolant and the secondary coolant calculated by the pressure difference calculation unit. 3. The high temperature gas cooled reactor steam generation system according to claim 2, wherein the pressure adjustment means includes a secondary coolant flow rate variable unit configured to increase a flow rate of the secondary coolant fed to the steam turbine. 4. The high temperature gas cooled reactor steam generation system according to claim 2, wherein the pressure adjustment means includes a secondary coolant bypass flow rate variable provided at a bypass circuit bypassing the secondary coolant to the steam turbine and configured to change the flow rate of the secondary coolant, and to increase the flow rate of the secondary coolant fed to the bypass circuit. 5. The high temperature gas cooled reactor steam generation system according to claim 1, wherein the pressure adjustment means includes a secondary coolant flow rate variable configured to increase a flow rate of the secondary coolant fed to the steam turbine. 6. The high temperature gas cooled reactor steam generation system according to claim 5, wherein the pressure adjustment means includes a secondary coolant bypass flow rate variable unit provided at a bypass circuit bypassing the secondary coolant to the steam turbine and configured to change the flow rate of the secondary coolant, and to increase the flow rate of the secondary coolant fed to the bypass circuit. 7. The high temperature gas cooled reactor steam generation system according to claim 1, wherein the pressure adjustment means includes a secondary coolant bypass flow rate variable unit provided at a bypass circuit bypassing the secondary coolant to the steam turbine and configured to change the flow rate of the secondary coolant, and to increase the flow rate of the secondary coolant fed to the bypass circuit. 8. The high temperature gas cooled reactor steam generation system according to claim 1, further comprising: temperature adjustment means configured to increase an outlet temperature of the secondary coolant in the steam generator according to the setting of the pressure by the pressure adjustment means. 9. The high temperature gas cooled reactor steam generation system according to claim 8, wherein the pressure adjustment means includes a secondary coolant discharging unit including a feed water pump configured to discharge the secondary coolant to the steam generator, and to decrease a discharging amount of the secondary coolant in the secondary coolant discharging unit by decreasing a rotation speed of the feed water pump based on the pressure difference between the primary coolant and the secondary coolant calculated by the pressure difference calculation unit. 10. The high temperature gas cooled reactor steam generation system according to claim 8, wherein the temperature adjustment means includes a primary coolant temperature variable unit configured to increase a temperature of the primary coolant in the nuclear reactor. 11. The high temperature gas cooled reactor steam generation system according to claim 8, further comprising: temperature control means configured to control the temperature adjustment means so that the outlet temperature of the secondary coolant is a predetermined temperature according to the set pressure of the secondary coolant.