Reactor power control apparatus of a natural circulation boiling water reactor and a feed water control apparatus and nuclear power generation plant

Abstract

In order to provide a reactor power control apparatus which can maintain a stable water level when reactivity control based on control rod operation and water level adjustment is performed, this invention comprises a turbine control which calculates the load set error signal from the error between the set target generator power value and the generator power that was fed back and outputs to the turbine control apparatus; control rod control in the natural circulation boiling water reactor which calculates the control rod operation signal and outputs it to the control rod drive control apparatus; water level control inside the natural circulation boiling water reactor which calculates the water level set signal and outputs it to the feed water control apparatus; and the switch determining device which selectively outputs one of the control rod control and water level control based on the generator power that was fed back, the reactor power and water level, as well as switching rules and determination values.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram of a nuclear power generation equipment which is an embodiment of the present invention.

FIG. 2 is a longitudinal section view of the reactor of this embodiment.

FIG. 3 is a structural diagram of reactor power control apparatus of this embodiment.

FIG. 4 is a structural diagram of the water level set value signal generator.

FIG. 5 is an explanatory drawing showing an example of start-up time reactor power control-reactor flow rate curve.

FIG. 6 is an explanatory drawing showing the method for fine adjustment of reactor power at the time of rated reactor power operation.

FIG. 7 is an explanatory drawing showing the method for fine adjustment of reactor power at rated reactor power operation.

FIG. 8 is an explanatory drawing showing an example of automatic stopping in the case where reactor water level setting is manual, which is another example of the present invention.

FIG. 9 is a structural diagram of a reactor power control apparatus which is another embodiment of the present invention.

FIG. 10 is a structural diagram of a reactor power control apparatus which is another example of the present invention.

FIG. 11 is a structural diagram of a reactor power control apparatus which is another embodiment of the present invention.

FIG. 12 is structural diagram of an example of a nuclear power generation plant and a control system using the nuclear power generation plant of another embodiment of the present invention.

FIG. 13 is a structural diagram an example of a feed water control apparatus of this embodiment.

FIG. 14 is a structural diagram of an example of the power control apparatus of this embodiment.

FIG. 15 is a timing chart showing an example of water level control of this embodiment.

FIG. 16 is a flowchart showing the control process status in the example of FIG. 15.

FIG. 17 is a timing chart showing an example of reactor water level control in this embodiment.

FIG. 18 is a flowchart showing the control process status in the example of FIG. 17.

FIG. 19 is a timing chart showing an example of reactor water level control in this embodiment.

FIG. 20 is a flowchart showing the control process status in the example of FIG. 19.

FIG. 21 is structural diagram showing a feed water control apparatus of another embodiment of the present invention.

FIG. 22 is a timing chart showing an example of reactor water level control of another embodiment of present invention.

Claims

1. A nuclear reactor power control apparatus of a natural circulation boiling water reactor comprising: turbine control which calculates load set error signal or load set signal based on first error between set target generator power value and generator power value that was fed back, or based on second error between target reactor power value and reactor power that was fed back, and outputs the load set error signal or the load set signal to a turbine control apparatus;control rod control in the natural circulation boiling water reactor which calculates control rod operation signal, and outputs it to a control rod drive control apparatus;reactor water level control in the natural circulation boiling water reactor which calculates reactor water level set signal, and outputs it to a feed water control apparatus; anda switch determining device which outputs one of the control rod control and the reactor water level control selected based on the reactor power, reactor water level and the generator power that was respectively fed back, switching rules and determination values.

2. A nuclear reactor power control apparatus of a natural circulation boiling water reactor comprising: turbine control which calculates load set error signal or load set signal based on first error between set target generator power value and generator power value that was fed back, or based on second error between target reactor power value and reactor power that was fed back, and outputs the load set error signal or the load set signal to a turbine control apparatus;control rod control in the natural circulation boiling water reactor which calculates control rod operation signal, and outputs it to a control rod drive control apparatus;reactor water level control in the natural circulation boiling water reactor which calculates reactor water level set signal, and outputs it to a feed water control apparatus; anda switch determining device which transmits a signal having the first error or the second error of zero to a feed water control apparatus when the control rod control is selected based on the reactor power, reactor water level and the generator power that was respectively fed back, switching rules and determination values.

3. A nuclear reactor power control apparatus of a natural circulation boiling water reactor comprising: turbine control which calculates load set error signal or load set signal based on reactor power error which is error between set target reactor power value and reactor power that was fed back, and outputs the load set error signal or the load set signal to a turbine control apparatus;control rod control in the natural circulation boiling water reactor which calculates control rod operation signal, and outputs it to a control rod drive control apparatus;reactor water level control in the natural circulation boiling water reactor which calculates reactor water level set signal, and outputs it to a feed water control apparatus; anda switch determining device which compares the reactor power, reactor water level and generator power that was respectively fed back and the switching rules and determination values stored respectively in the memory apparatus, and switches between the control rod control and the reactor water level control based on the results of the comparison.

4. A nuclear reactor power control apparatus of a natural circulation boiling water reactor comprising: turbine control which calculates load set error signal or load set signal based on first error between set target generator power value and generator power value that was fed back, or based on second error between target reactor power value and reactor power that was fed back, and outputs the load set error signal or the load set signal to a turbine control apparatus;control rod control in the natural circulation boiling water reactor which calculates control rod operation signal, and outputs it to a control rod drive control apparatus;reactor water level control which calculates reactor water level set signal based on the error between set core flow rate set value and core flow rate measured value, and outputs it to the feed water control apparatus; anda switch determining device which outputs one of the control rod control and the reactor water level control selected based on the reactor power, reactor water level and the generator power that was respectively fed back, switching rules and determination values.

5. A nuclear reactor power control apparatus of a natural circulation boiling water reactor comprising: turbine control which calculates load set error signal or load set signal based on first error between set target generator power value and generator power value that was fed back, or based on second error between target reactor power value and reactor power that was fed back, and outputs the load set error signal or the load set signal to the turbine control apparatus;control rod control in the natural circulation boiling water reactor which calculates control rod operation signal, and outputs it to a control rod drive control apparatus;reactor water level control for controlling reactor water level based on the error between the set core minimum critical power ratio and the minimum critical power ratio evaluated by the process computer; anda switch determining device which switches between the control rod control and the reactor water level control based on the reactor power, reactor water level, the minimum critical power ratio and the generator power that was respectively fed back and the switching rules and determination values stored respectively in the memory apparatus.

6. The nuclear reactor power control apparatus of a natural circulation boiling water reactor according to any one of claims 1 to 5, further comprising: a standard water level signal generator for generating standard water level signal,wherein the switch determining device selects one of the output of the control rod operation signal to the control rod drive control apparatus and the output of the reactor water level set signal to the feed water control apparatus based on conversion rules and determination values.

7. The nuclear reactor power control apparatus of a natural circulation boiling water reactor according to claim 6, further comprising: a manual switching device for selecting operations for manual switching,wherein when the selected operation for switching is set, and the switching signal from the switch determining device is in the OFF state, one of the output of the control rod operation signal to the control rod drive control apparatus and the output of the reactor water level set signal to the feed water control apparatus selected by switching signal from the manual switching device.

8. The nuclear reactor power control apparatus of a natural circulation boiling water reactor according to any one of claims 1, 3, 4 and 5, wherein when the control rod control is selected by the switch determining device, fixed water level set signal is output to the water level control apparatus.

9. The nuclear reactor power control apparatus of a natural circulation boiling water reactor according to any one of claims 1 to 4, further comprising: a power limiter for limiting reactor power such that the water level set signal includes in the water level setting range.

10. The nuclear reactor power control apparatus of a natural circulation boiling water reactor according to claim 5, wherein reactor water level set value is increased at a fixed change ratio by a water level setting increasing device, when the minimum critical power ratio error which is the error between the minimum critical power ratio and the set signal, and the reactor water level set value is output to the reactor water level control system as the water level set signal.

11. A feed water control apparatus for a natural circulation boiling water reactor comprising a reactor pressure vessel, a chimney arranged in the reactor pressure vessel, a coolant ascending path formed in the chimney, a coolant descending path formed between rate and the measured-reactor water level.

13. The feed water control apparatus for a natural circulation boiling water reactor according to claim 11, further comprising: first and second reactor water level measuring apparatuses each having different detection ranges and provided with the reactor pressure vessel,wherein the reactor water level control apparatus selects one of first reactor water level signal from the first reactor water level measuring apparatus and second reactor water level signal from the second reactor water level measuring apparatus based on a target water level control range, and uses the selected reactor water level signal as said measured reactor water level signal.

14. The feed water control apparatus for a natural circulation boiling water reactor according to claim 11, wherein the feed water control using the feed water flow rate control signal from the water level control apparatus is performed in the period of stable operation and substantially in the rated reactor power state.

15. A nuclear power generation plant comprising: a natural circulation boiling water reactor having a reactor pressure vessel, a chimney arranged in the the reactor pressure vessel and the chimney, comprising:a reactor water level control apparatus for detecting error for reactor water level set value based on the flow rate of steam exhausted from the reactor pressure vessel, the flow rate of feed water being supplied to the reactor pressure vessel, measured reactor water level signal and the reactor water level set value, and calculating flow rate control signal of feed water being supplied to the reactor pressure vessel based on the error for the reactor water level set value and load demand error signal: anda pump drive apparatus for generating rotation speed command of feed water pump which pressurizes the feed water, based on the feed water flow rate control signal from the reactor water level control apparatus.

12. The feed water control apparatus for a natural circulation boiling water reactor according to claim 11, wherein the reactor water level control apparatus generates added signal by adding signal corresponding to the reactor power control signal to the reactor water level set value, and detects the error for the reactor water level set value based on the added signal, the main steam flow rate, the feed water flow reactor pressure vessel, a coolant ascending path formed in the chimney and a coolant descending path between the reactor pressure vessel and the chimney; a turbine being driven by steam exhausted from the reactor pressure vessel;a condensing apparatus for condensing the steam exhausted from the turbine;a feed water pump for supplying feed water exhausted from the condensing apparatus to the reactor pressure vessel;a steam flow rate measuring apparatus for measuring flow rate of the steam introduced to the turbine;a feed water flow rate measuring apparatus for measuring the flow rate of the feed water;reactor water level measuring apparatuses for measuring reactor water level in the reactor pressure vessel;a reactor water level control apparatus for detecting error for reactor water level set value based on the steam flow rate measured by the steam flow rate measuring apparatus, the feed water flow rate measured by the feed water flow rate measuring apparatus, the reactor water level signal measured by the water level measuring apparatus and the reactor water level set value, and calculating flow rate control signal of the feed water based on the error for the reactor water level set value and load demand error signal; anda pump drive apparatus for generating rotation speed command of the feed water pump based on the feed water flow rate control signal from the reactor water level control apparatus.

16. The nuclear power generation plant according to claim 15, further comprising: a reactor power control apparatus for generating reactor power control signal,wherein the water level control apparatus generates added signal by adding signal corresponding to the reactor power control signal to the reactor water level set value, and detects the error for the reactor water level set value based on the added signal, the main steam flow rate, the feed water flow rate and the measured reactor water level.

17. The nuclear power generation plant according to claim 15, wherein the reactor water level measuring apparatuses include a first water level measuring apparatus and a second water level measuring apparatus each having different detection ranges, and the reactor water level control apparatus selects one of first reactor water level signal from the first reactor water level measuring apparatus and second reactor water level signal from the second reactor water level measuring apparatus based on a target water level control range, and uses the selected reactor water level signal as said measured reactor water level signal.

18. The nuclear power generation plant according to claim 15, wherein the feed water control using the feed water flow rate control signal from the water level control apparatus is performed in the period of stable operation and substantially in the rated reactor power state.