Pressurizer water level control method, pressurizer water level control program, and pressurizer water level control device.

Abstract

To suppress a rise in water level of a pressurizer when a filling flow control valve malfunctions.SOLUTION: A pressurizer water level control method comprises a step (S1) of acquiring a water level of a pressurizer connected to a primary coolant system during a steady-state operation of a nuclear reactor, steps (S1, S2) of adjusting a primary coolant filling flow rate from an extraction flow rate of the primary coolant from the primary coolant system 10 and a filling flow rate of the primary coolant based on the water level of a pressurizer 14, and a step (S5) of increasing an extraction amount of the primary coolant when the estimated filling flow rate based on the adjustment of the filling flow rate is inconsistent with an actual filling flow rate (S3) and the water level of the pressurizer 14 is high (S4).SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a pressurizer water level control method, a pressurizer water level control program, and a pressurizer water level control device.

Background Art

[0002] In a pressurized water reactor, a pressurizer maintains a constant pressure in the primary coolant system. The pressurizer is a tank-shaped device provided between the reactor and the steam generator, and there is a water level at the boundary between the liquid phase and the gas phase inside it. In a pressurized water reactor, by controlling the water level of the pressurizer, the amount of primary coolant is appropriately maintained and the pressure is held. For example, Patent Documents 1 and 2 describe methods for controlling the water level of a pressurizer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] A constant amount of the primary coolant inside the pressurizer is constantly extracted from the viewpoint of water quality management and the like, and it is filled to supplement it so that a constant amount of water is maintained. Here, as a method for maintaining the amount of water in the pressurizer, there is a mechanism for keeping the water level of the pressurizer constant by making the extraction flow rate constant at all times and finely adjusting the filling flow rate. At this time, if the filling flow control valve that adjusts the filling flow rate becomes fixed in a state where the filling flow rate is larger than the extracted flow rate, there is no way to control the water level of the pressurizer, so the water level of the pressurizer continues to rise, and ultimately the water level of the pressurizer can reach a high set value. As a result, when a dangerous state is predicted in the reactor, the control rod will be quickly inserted into the reactor to urgently stop the nuclear fission chain reaction (reactor trip).

[0005] This disclosure aims to solve the above-mentioned problems and to provide a pressurizer water level control method, a pressurizer water level control program, and a pressurizer water level control device that can suppress the rise in the pressurizer water level when the filling flow control valve malfunctions. [Means for solving the problem]

[0006] To achieve the above-mentioned objectives, a pressurizer water level control method according to one aspect of the present disclosure includes the steps of: obtaining the water level of a pressurizer connected to the primary coolant system during steady-state operation of a nuclear reactor; adjusting the primary coolant filling flow rate from the primary coolant extraction flow rate and the primary coolant filling flow rate based on the water level of the pressurizer; and increasing the amount of primary coolant extracted if the estimated filling flow rate based on the adjustment of the filling flow rate is inconsistent with the actual filling flow rate and the pressurizer is at a high water level.

[0007] To achieve the above-mentioned objectives, a pressurizer water level control program according to one aspect of the present disclosure causes a computer to perform the following steps: acquire the water level of a pressurizer connected to the primary coolant system during steady-state operation of the reactor; adjust the primary coolant filling flow rate from the primary coolant extraction flow rate and the primary coolant filling flow rate based on the water level of the pressurizer; determine the consistency between the estimated filling flow rate and the actual filling flow rate based on the adjustment of the filling flow rate, and the water level fluctuation of the pressurizer; and increase the amount of primary coolant extracted if the estimated filling flow rate and the actual filling flow rate are inconsistent and the pressurizer is at a high water level.

[0008] To achieve the above-mentioned objectives, a pressurizer water level control device according to one aspect of the present disclosure controls an extraction unit for extracting primary coolant from the primary coolant system and a filling unit for filling the primary coolant system, which are connected to a water level gauge for measuring the water level of a pressurizer connected to the primary coolant system of a nuclear reactor, an extraction flow meter for measuring the extraction flow rate of the primary coolant, and a filling flow meter for measuring the filling flow rate of the primary coolant, and the pressurizer water level control device controls the filling unit for filling the primary coolant system, and includes a filling flow rate adjustment unit that adjusts the filling flow rate by the filling unit based on the water level of the water level gauge and the filling flow rate of the filling flow meter during steady operation of the nuclear reactor, and an extraction amount adjustment unit that increases the extraction amount by the extraction unit when the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate of the filling flow meter are inconsistent and the pressurizer is at a high water level. [Effects of the Invention]

[0009] This disclosure makes it possible to suppress the rise in the water level of the pressurizer when the filling flow control valve malfunctions. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram of the reactor primary coolant system including the pressurizer water level control device of an embodiment. [Figure 2] Figure 2 is a block diagram of the pressurizer water level control device according to an embodiment. [Figure 3] Figure 3 is a control block diagram of the pressurizer water level control device according to the embodiment. [Figure 4] Figure 4 is a flowchart of the pressurizer water level control method according to the embodiment. [Figure 5] Figure 5 is a diagram showing the operating timing according to the pressurizer water level control method of the embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited by these embodiments. Furthermore, some of the components in the following embodiments may be easily substituted or substantially identical to those that are easily substituted by those skilled in the art.

[0012] As shown in Figure 1, the reactor primary coolant system 10 mainly includes the reactor 11, the steam generator 12, and the circulation line 13.

[0013] Reactor 11 is a pressurized water reactor (PWR), and its interior is filled with a primary coolant. The primary coolant is light water in which boron, used as a neutron moderator, is dissolved. Inside reactor 11, numerous fuel assemblies are housed, forming the reactor core. In reactor 11, the primary coolant inside is heated by the thermal energy generated by the nuclear fission of the fuel assemblies.

[0014] The steam generator 12 is connected to the reactor 11 via the hot leg 13A and cold leg 13B of the circulation line 13. The steam generator 12 has many heat transfer tubes through which the primary coolant flows, with the hot leg 13A connected to one end of each heat transfer tube and the cold leg 13B connected to the other end. The steam generator 12 is supplied with secondary coolant inside, outside the heat transfer tubes.

[0015] The circulation line 13 has the hot leg 13A and the cold leg 13B. The circulation line 13 is provided with a primary coolant pump 13C in the cold leg 13B.

[0016] Therefore, in the primary coolant system 10 of the nuclear reactor, the primary coolant circulates between the nuclear reactor 11 and the steam generator 12 via the circulation line 13. Specifically, in the primary coolant system 10 of the nuclear reactor, the primary coolant heated in the nuclear reactor 11 is sent to the steam generator 12 via the hot leg 13A by the primary coolant pump 13C. Further, in the primary coolant system 10 of the nuclear reactor, the primary coolant flowing into the steam generator 12 is cooled by performing heat exchange with the secondary coolant without contact, and the cooled primary coolant is sent to the nuclear reactor 11 via the cold leg 13B by the primary coolant pump 13C.

[0017] This primary coolant system 10 of the nuclear reactor further includes a pressurizer 14, an extraction unit 15, and a filling unit 16.

[0018] The pressurizer 14 is formed in a tank shape and is connected to the hot leg 13A. The pressurizer 14 stores and pressurizes a part of the high-temperature primary coolant passing through the hot leg 13A. The pressurized primary coolant flows into the steam generator 12 in a state where boiling is suppressed and it becomes high temperature and high pressure. The pressurizer 14 is provided with a water level gauge 14A. The water level gauge 14A measures the water level of the liquid phase of the primary coolant, for example, by the vertical pressure difference between the gas phase and the liquid phase of the primary coolant inside the pressurizer 14.

[0019] The extraction unit 15 is connected to the cold leg 13B and extracts a portion of the primary coolant. The extraction unit 15 has an extraction line 15A connected to the cold leg 13B. The extraction unit 15 is provided with an on-off valve 15B and an orifice 15C in each of the three parallel lines into which the extraction line 15A is divided. The extraction unit 15 is provided with an extraction flow meter 15D on the upstream side (cold leg 13B side) before the extraction line 15A is divided into three sections. Therefore, the extraction unit 15 extracts a portion of the primary coolant from the cold leg 13B through the orifice 15C of the line in which the on-off valve 15B is opened. When the on-off valves 15B of each line are opened together, the amount of primary coolant extracted increases by adding the orifice 15C of each line in the extraction unit 15. In the reactor primary coolant system 10 of this embodiment, during steady-state operation (when the reactor 11 is operating at its rated capacity), the extraction unit 15 keeps only one of the three lines, the on-off valve 15B, open at all times, and a fixed amount of primary coolant is extracted. The extraction flow rate of the primary coolant extracted through the extraction line 15A is measured by the extraction flow meter 15D.

[0020] The filling unit 16 is connected to the cold leg 13B and fills it with primary coolant. The filling unit 16 has a filling line 16A connected to the cold leg 13B. The filling line 16A is connected to a filling tank (not shown) where the primary coolant is stored. The filling unit 16 is equipped with a filling flow control valve 16B and a filling pump 16C in the filling line 16A. The filling unit 16 is equipped with a filling flow meter 16D between the filling flow control valve 16B and the filling pump 16C in the filling line 16A. Therefore, when the filling flow control valve 16B is opened and the filling pump 16C is driven, the filling unit 16 fills the cold leg 13B with primary coolant via the filling line 16A. In the filling section 16, the filling flow rate of the primary coolant to the cold leg 13B is adjusted by adjusting the opening degree of the filling flow rate control valve 16B. In the filling section 16, the filling flow rate of the primary coolant being filled via the filling line 16A is measured by the filling flow meter 16D.

[0021] The pressurizer water level control device 1 of the embodiment is provided in the reactor primary coolant system 10 described above. The pressurizer water level control device 1 is a computer and includes a storage unit 2, a charging flow rate adjustment unit 3, and an extraction amount adjustment unit 4, as shown in FIG. 2.

[0022] The storage unit 2 is a memory that stores various information such as the calculation content and programs of the charging flow rate adjustment unit 3 and the extraction amount adjustment unit 4. For example, it includes at least one of a main storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and an external storage device such as an HDD (Hard Disk Drive).

[0023] The charging flow rate adjustment unit 3 is an arithmetic device and includes an arithmetic circuit such as a CPU (Central Processing Unit). As shown in FIG. 3, the charging flow rate adjustment unit 3 includes a first PI arithmetic unit 3A and a second PI arithmetic unit 3B. The charging flow rate adjustment unit 3 reads and executes a program (software) from the storage unit 2 to realize the first PI arithmetic unit 3A and the second PI arithmetic unit 3B and execute their processes. Note that the charging flow rate adjustment unit 3 may execute the process by one CPU, or may be provided with a plurality of CPUs and execute the process with these plurality of CPUs. Also, the charging flow rate adjustment unit 3 may realize the first PI arithmetic unit 3A and the second PI arithmetic unit 3B with a hardware circuit. Further, the program for the charging flow rate adjustment unit 3 stored in the storage unit 2 may be stored in a recording medium readable by the pressurizer water level control device 1.

[0024] The charging flow rate adjustment unit 3 acquires the water level of the pressurizer 14 measured by the water level gauge 14A. The charging flow rate adjustment unit 3 acquires the extraction flow rate of the extraction unit 15 measured by the extraction flow meter 15D. The charging flow rate adjustment unit 3 acquires the charging flow rate of the charging unit 16 measured by the charging flow meter 16D. Also, the charging flow rate adjustment unit 3 adjusts the opening degree of the charging flow rate control valve 16B of the charging unit 16.

[0025] The extraction volume adjustment unit 4 is an arithmetic unit and includes an arithmetic circuit such as a CPU. As shown in Figure 3, the extraction volume adjustment unit 4 includes a determination unit 4A. The extraction volume adjustment unit 4 implements the determination unit 4A and performs the processing by reading and executing a program (software) from the storage unit 2. The extraction volume adjustment unit 4 may perform the processing with one CPU, or it may have multiple CPUs and perform the processing with those multiple CPUs. Furthermore, the extraction volume adjustment unit 4 may implement the determination unit 4A with a hardware circuit. In addition, the program for the extraction volume adjustment unit 4 stored in the storage unit 2 may be stored on a recording medium that can be read by the pressurizer water level control device 1.

[0026] The extraction volume adjustment unit 4 acquires the water level of the pressurizer 14 measured by the water level gauge 14A. The extraction volume adjustment unit 4 acquires the filling flow rate (actual filling flow rate) of the filling unit 16 measured by the filling flow meter 16D. The extraction volume adjustment unit 4 acquires the estimated filling flow rate based on the opening degree of the filling flow control valve 16B adjusted by the filling flow rate adjustment unit 3. Alternatively, the extraction volume adjustment unit 4 may acquire the extraction flow rate of the extraction unit 15 measured by the extraction flow meter 15D instead of the estimated filling flow rate. Furthermore, the extraction volume adjustment unit 4 increases the extraction amount of primary coolant by opening the on / off valve 15B of the extraction unit 15.

[0027] The pressurizer water level control method, which is the operation of the pressurizer water level control device 1, will be explained with reference to Figures 3 to 5.

[0028] As shown in Figures 3 and 4, the pressurizer water level control device 1 acquires the water level of the pressurizer 14, the filling flow rate of the filling section 16, and the extraction flow rate of the extraction section 15 during steady-state operation of the reactor 11 (step S1). During steady-state operation of the reactor 11, the water level of the pressurizer 14 is between 50% and 60%.

[0029] The pressurizer water level control device 1 sets the opening degree of the filling flow control valve 16B in the filling flow rate adjustment unit 3 (step S2). In step S2, as shown in Figure 3, the filling flow rate adjustment unit 3 takes the difference between the water level in the pressurizer 14 and the target water level that has been set in advance and stored in the memory unit 2, and performs integral control in the first PI calculation unit 3A. In step S2, the filling flow rate adjustment unit 3 also takes the difference between the filling flow rate and the extraction flow rate and performs integral control in the second PI calculation unit 3B. As a result, the filling flow rate adjustment unit 3 sets the opening degree of the filling flow control valve 16B.

[0030] The pressurizer water level control device 1 controls the extraction amount in the determination unit 4A of the extraction amount adjustment unit 4 (steps S3 to S9).

[0031] In step S3, the determination unit 4A compares the estimated filling flow rate (actual extraction flow rate of the extraction unit 15) with the actual filling flow rate and determines whether these flow rates are inconsistent. The estimated filling flow rate is the filling flow rate estimated by the opening degree of the filling flow rate control valve 16B set in the filling flow rate adjustment unit 3. The actual filling flow rate is the filling flow rate measured by the filling flow meter 16D. The determination unit 4A determines that there is an inconsistency if the comparison result is, for example, that the actual filling flow rate is greater than the difference range of each flow rate that has been set in advance and stored in the storage unit 2. In this case, it is possible that there is a malfunction in the operation of the filling flow rate control valve 16B and that it is opening to a degree exceeding the set opening degree. On the other hand, the determination unit 4A determines that there is an inconsistency if the comparison result is, for example, within the range of the difference between each flow rate that has been set in advance and stored in the storage unit 2. If an inconsistency is determined in step S3 (step S3: Yes), the process proceeds to step S4. On the other hand, if consistency is determined in step S3 (step S3: No), the process returns to step S1.

[0032] In step S4, the determination unit 4A determines whether the water level in the pressurizer 14 is high. High water level means that the acquired water level exceeds a predetermined level (for example, 65%). The predetermined level is set in advance and stored in the memory unit 2. High water level also means that the water level is trending upward. An upward trend means that the rate of increase in the water level over a predetermined time exceeds the rate of increase that is set in advance and stored in the memory unit 2. If it is determined in step S4 that the water level is high (step S4: Yes), the process proceeds to step S5. On the other hand, if it is determined in step S4 that the water level is not high (step S4: No), the process returns to step S1.

[0033] In step S5, the determination unit 4A increases the extraction amount based on the determinations made in steps S3 and S4. In the pressurizer water level control device 1 of the embodiment, the extraction amount adjustment unit 4 increases the extraction amount of the primary coolant by opening one of the remaining two on-off valves 15B that are closed in the extraction unit 15.

[0034] In step S6, the determination unit 4A determines whether a predetermined time has elapsed since the processing in step S5. The predetermined time is, for example, 5 to 10 minutes, and is indicated by the symbol T in Figure 5. If the predetermined time has elapsed in step S6 (step S6: Yes), the process proceeds to step S7. On the other hand, if the predetermined time has not elapsed in step S6 (step S6: No), step S6 is repeated.

[0035] In step S7, after processing in step S5, the determination unit 4A determines whether there is a mismatch, similar to step S3. If a mismatch is determined in step S7 (step S7: Yes), the process proceeds to step S8. On the other hand, if a consistency is determined in step S7 (step S7: No), this control is terminated.

[0036] In step S8, the determination unit 4A determines whether the water level is high, similar to step S4. If it determines in step S8 that the water level is high (step S8: Yes), the process proceeds to step S9. On the other hand, if it determines in step S8 that the water level is not high (step S8: No), this control process ends.

[0037] In step S9, the determination unit 4A increases the extraction amount based on the determinations made in steps S7 and S8. In the pressurizer water level control device 1 of this embodiment, the extraction amount adjustment unit 4 increases the extraction amount of primary coolant by opening the other of the two remaining on-off valves 15B that are closed in the extraction unit 15. After the processing in step S9, the control is terminated or restarted from step S1. If the water level in the pressurizer 14 is trending downwards after the processing in step S9, the other of the two remaining on-off valves 15B may be closed.

[0038] In the operation of the pressurizer water level control device 1 described above, if the process in step S5 is not performed, for example, as shown by the solid line A in Figure 5, the water level in the pressurizer 14 will rise to the level that would cause a reactor trip at time T0 after the water level has started to rise. In contrast, in the pressurizer water level control device 1 (pressurizer water level control method, pressurizer water level control program) of the embodiment, by opening one of the remaining two on-off valves 15B that are closed in the extraction unit 15 in step S5, for example, as shown by the dashed line B in Figure 5, the rise in the water level in the pressurizer 14 is delayed, so that a margin of time T0 to time T1 is obtained before the water level reaches the level that would cause a reactor trip compared to the solid line A. Furthermore, in the pressurizer water level control device 1 (pressurizer water level control method, pressurizer water level control program) of the embodiment, by opening the other of the remaining two on-off valves 15B that are closed in the extraction unit 15 in step S9, for example, as shown by the dashed line C in Figure 5, the rise in the water level of the pressurizer 14 is further delayed, thus providing a further extended margin of time T0 to time T2 until the water level reaches the level that would cause a reactor trip, relative to the solid line A.

[0039] As described above, the pressurizer water level control method of the embodiment described above includes the steps of: obtaining the water level of a pressurizer 14 connected to the primary coolant system 10 during steady-state operation of the reactor 11; adjusting the primary coolant filling flow rate from the primary coolant extraction flow rate and the primary coolant filling flow rate based on the water level of the pressurizer 14; and increasing the amount of primary coolant extracted if the estimated filling flow rate based on the adjustment of the filling flow rate is inconsistent with the actual filling flow rate and the pressurizer 14 is at a high water level.

[0040] According to this pressurizer water level control method, if there is a mismatch between the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate, and if the water level in the pressurizer 14 is high, it can be determined that there is a malfunction in the filling flow rate control valve 16B, and by taking measures to increase the amount of primary coolant extracted, the rise in the water level of the pressurizer 14 can be suppressed. As a result, the pressurizer water level control method of this embodiment can enhance the ability to continue operation by avoiding unnecessary reactor trips, or it can minimize the impact of power generation on the power grid during a reactor trip by gaining time before a reactor trip occurs.

[0041] Furthermore, the pressurizer water level control method of the embodiment further includes a step of further increasing the amount of primary coolant extracted if, after a certain period of time when the amount of primary coolant extracted has been increased, the estimated filling flow rate and the actual filling flow rate are inconsistent and the pressurizer water level is high.

[0042] This pressurizer water level control method provides more time to repair the filling flow control valve 16B before a reactor trip occurs. In particular, the pressurizer water level control method of this embodiment can suppress the potential impact on downstream systems of the primary coolant system by gradually increasing the extraction amount.

[0043] Furthermore, in the pressurizer water level control method of the embodiment, multiple orifices for extracting the primary coolant are arranged, and the step of increasing the amount of primary coolant extracted involves increasing the number of open orifice systems.

[0044] According to this pressurizer water level control method, the orifice maintains a constant flow rate, allowing for a stable increase in the extraction flow rate. Furthermore, multiple orifice systems for extracting the primary coolant are generally provided in the primary coolant system of a pressurized water reactor, and such equipment can be utilized.

[0045] Furthermore, in the pressurizer water level control method of the embodiment, the water level of the pressurizer 14 can be determined when it exceeds a predetermined water level in the pressurizer 14.

[0046] Furthermore, in the pressurizer water level control method of the embodiment, the water level of the pressurizer 14 can be determined when the water level of the pressurizer 14 is on an upward trend.

[0047] Furthermore, in the pressurizer water level control method of the embodiment, the relationship between the estimated filling flow rate and the actual filling flow rate can be replaced with the relationship between the extraction flow rate and the actual filling flow rate.

[0048] The pressurizer water level control program of the embodiment causes the computer to perform the following steps: acquire the water level of the pressurizer 14 connected to the primary coolant system 10 during steady operation of the reactor 11; adjust the primary coolant filling flow rate from the primary coolant extraction flow rate and the primary coolant filling flow rate based on the water level of the pressurizer 14; and increase the amount of primary coolant extracted if the estimated filling flow rate based on the adjustment of the filling flow rate does not match the actual filling flow rate and the pressurizer 14 is at a high water level.

[0049] According to this pressurizer water level control program, if there is a mismatch between the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate, and if the water level in the pressurizer 14 is high, it can be determined that there is a malfunction in the filling flow rate control valve 16B, and by taking measures to increase the amount of primary coolant extracted, the rise in the water level of the pressurizer 14 can be suppressed. As a result, the pressurizer water level control program of this embodiment can enhance the ability to continue operation by avoiding unnecessary reactor trips, or it can minimize the impact of power generation on the power grid during a reactor trip by gaining time before a reactor trip occurs.

[0050] The pressurizer water level control device of this embodiment controls a pressurizer water level control unit that controls an extraction unit 15 that extracts primary coolant from the primary coolant system 10 and a filling unit 16 that fills the primary coolant into the primary coolant system 10, connected to a water level gauge 14A that measures the water level of a pressurizer 14 connected to the primary coolant system 10 of the reactor 11, an extraction flow meter 15D that measures the extraction flow rate of the primary coolant, and a filling flow meter 16D that measures the filling flow rate of the primary coolant. The apparatus 1 includes a filling flow rate adjustment unit 3 that adjusts the filling flow rate by the filling unit 16 based on the water level of the water level gauge 14A during steady operation of the reactor 11, using the extraction flow rate of the extraction flow meter 15D and the filling flow rate of the filling flow meter 16D as a basis, and an extraction amount adjustment unit 4 that increases the extraction amount by the extraction unit 15 when the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate of the filling flow meter 16D are mismatched and the water level of the pressurizer 14 is high.

[0051] According to this pressurizer water level control device, if there is a mismatch between the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate, and if the water level in the pressurizer 14 is high, it can be determined that there is a malfunction in the filling flow rate control valve 16B, and by taking measures to increase the amount of primary coolant extracted, the rise in the water level of the pressurizer 14 can be suppressed. As a result, the pressurizer water level control device of this embodiment can enhance the ability to continue operation by avoiding unnecessary reactor trips, or it can minimize the impact on the power grid of power generation during a reactor trip by gaining time before a reactor trip occurs.

[0052] This disclosure includes the following inventions: [Invention 1] The steps include obtaining the water level in a pressurizer connected to the primary coolant system during steady-state operation of the reactor, A step of adjusting the filling flow rate of the primary coolant from the primary coolant system based on the water level of the pressurizer and the filling flow rate of the primary coolant, If the estimated filling flow rate based on the adjustment of the filling flow rate is inconsistent with the actual filling flow rate, and the pressurizer is at a high water level, the step of increasing the amount of primary coolant extracted, A method for controlling the water level of a pressurizer, including the method described above. [Invention 2] A pressurizer water level control method according to Invention 1, further comprising the step of further increasing the amount of primary coolant extracted if, after a certain period of time, the estimated filling flow rate and the actual filling flow rate are inconsistent and the pressurizer is at a high water level. [Invention 3] A pressurizer water level control method according to invention 1 or 2, wherein the step of increasing the amount of primary coolant extracted by arranging multiple orifices is to increase the number of open orifice systems. [Invention 4] A method for controlling the water level of a pressurizer according to any one of inventions 1 to 3, wherein the water level of the pressurizer exceeds a predetermined water level in the pressurizer. [Invention 5] The pressurizer water level control method according to any one of inventions 1 to 3, wherein the water level of the pressurizer is such that the water level of the pressurizer tends to rise. [Invention 6] A pressurizer water level control method according to any one of Inventions 1 to 5, wherein the relationship between the estimated filling flow rate and the actual filling flow rate is replaced with the relationship between the extraction flow rate and the actual filling flow rate. [Invention 7] The steps include obtaining the water level in a pressurizer connected to the primary coolant system during steady-state operation of the reactor, A step of adjusting the filling flow rate of the primary coolant from the primary coolant system based on the water level of the pressurizer and the filling flow rate of the primary coolant, The steps include determining the consistency between the estimated filling flow rate and the actual filling flow rate based on the adjustment of the filling flow rate, and determining the water level fluctuation in the pressurizer, If the estimated filling flow rate and the actual filling flow rate are inconsistent, and the pressurizer is at a high water level, the step of increasing the amount of primary coolant extracted, Make the computer execute it. Pressurizer water level control program. [Invention 8] A pressurizer water level control device that controls an extraction unit for extracting primary coolant from the primary coolant system and a filling unit for filling the primary coolant system, which are connected to a water level gauge for measuring the water level of a pressurizer connected to the primary coolant system of a nuclear reactor, an extraction flow meter for measuring the extraction flow rate of the primary coolant, and a filling flow meter for measuring the filling flow rate of the primary coolant, wherein the pressurizer water level control device controls the extraction unit for extracting primary coolant from the primary coolant system and the filling unit for filling the primary coolant system, A filling flow rate adjustment unit adjusts the filling flow rate by the filling unit based on the water level of the water level gauge during steady operation of the reactor, using the extraction flow rate of the extraction flow meter and the filling flow rate of the filling flow meter. If the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate of the filling flow meter are inconsistent, and the pressurizer is at a high water level, the extraction amount adjustment unit increases the extraction amount by the extraction unit. A pressurizer water level control device, including a pressurizer water level control device. [Explanation of Symbols]

[0053] 1. Pressurizer water level control device 3. Filling flow rate adjustment section 4 Extraction amount adjustment section 10 Primary coolant system 11 Nuclear reactor 14 Pressurizer 14A water level gauge 15 Extraction part 15C Orifice 15D Extraction Flowmeter 16 Filling section 16D Filling Flow Meter

Claims

1. The steps include obtaining the water level in a pressurizer connected to the primary coolant system during steady-state operation of the reactor, A step of adjusting the filling flow rate of the primary coolant from the primary coolant system based on the water level of the pressurizer and the filling flow rate of the primary coolant, If the estimated filling flow rate based on the adjustment of the filling flow rate is inconsistent with the actual filling flow rate, and the pressurizer is at a high water level, the step of increasing the amount of primary coolant extracted, A method for controlling the water level of a pressurizer, including the method described above.

2. The pressurizer water level control method according to claim 1, further comprising the step of further increasing the amount of primary coolant extracted if, after a certain period of time, the estimated filling flow rate and the actual filling flow rate are inconsistent and the pressurizer is at a high water level.

3. The pressurizer water level control method according to claim 1, wherein the step of arranging multiple orifices for extracting the primary coolant and increasing the amount of the primary coolant extracted is to increase the number of open orifice systems.

4. The pressurizer water level control method according to claim 1, wherein the water level of the pressurizer exceeds a predetermined water level in the pressurizer.

5. The pressurizer water level control method according to claim 1, wherein the water level of the pressurizer is such that the water level of the pressurizer tends to rise.

6. The pressurizer water level control method according to claim 1, wherein the relationship between the estimated filling flow rate and the actual filling flow rate is replaced with the relationship between the extraction flow rate and the actual filling flow rate.

7. The steps include obtaining the water level in a pressurizer connected to the primary coolant system during steady-state operation of the reactor, A step of adjusting the filling flow rate of the primary coolant from the primary coolant system based on the water level of the pressurizer and the filling flow rate of the primary coolant, The steps include determining the consistency between the estimated filling flow rate and the actual filling flow rate based on the adjustment of the filling flow rate, and determining the water level fluctuation in the pressurizer, If the estimated filling flow rate and the actual filling flow rate are inconsistent, and the pressurizer is at a high water level, the step of increasing the amount of primary coolant extracted, Make the computer execute it. Pressurizer water level control program.

8. A pressurizer water level control device that controls an extraction unit for extracting primary coolant from the primary coolant system and a filling unit for filling the primary coolant system, which are connected to a water level gauge for measuring the water level of a pressurizer connected to the primary coolant system of a nuclear reactor, an extraction flow meter for measuring the extraction flow rate of the primary coolant, and a filling flow meter for measuring the filling flow rate of the primary coolant, wherein the pressurizer water level control device controls the extraction unit for extracting primary coolant from the primary coolant system and the filling unit for filling the primary coolant system, A filling flow rate adjustment unit adjusts the filling flow rate by the filling unit based on the water level of the water level gauge during steady operation of the reactor, using the extraction flow rate of the extraction flow meter and the filling flow rate of the filling flow meter. If the estimated filling flow rate based on the adjustment of the filling flow rate and the actual filling flow rate of the filling flow meter are inconsistent, and the pressurizer is at a high water level, the extraction amount adjustment unit increases the extraction amount by the extraction unit. A pressurizer water level control device, including a pressurizer water level control device.

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