JP7228477B2 - Residual heat removal equipment, its operating method and residual heat removal method - Google Patents

Description

An embodiment of the present invention relates to a residual heat removal technique for removing decay heat generated after stopping the operation of a nuclear reactor plant.

Boiling water reactors are equipped with a mechanism to properly remove decay heat from the reactor core even in the event of a severe accident in which the primary system piping breaks and the coolant in the pressure vessel leaks out. Residual heat removal equipment that exerts such decay heat removal function is (i) low pressure water injection mode, (ii) containment vessel cooling mode, (iii) shutdown cooling mode, (iv) pressure suppression chamber pool water cooling mode. , (v) spent fuel pool water cooling mode. Among these, operation modes (i) and (ii) are executed in an emergency such as when a severe accident occurs, and operation modes (iii), (iv) and (v) are when the reactor is in a normal state. executed at some normal time.

The residual heat removal equipment uses the pool water contained in the suppression chamber as a water source. and a heat exchanger for removing heat from the water. Furthermore, the exhaust heat recovered by this heat exchanger is released to the outside by a reactor auxiliary cooling system using seawater or the like as a coolant.

Until now, residual heat removal equipment has been designed on the assumption that the upper limit temperature of the pool water in the suppression chamber is 100°C when a severe accident occurs. In other words, it was assumed that the temperature of the pool water would not exceed 100°C even if the pipe with the largest diameter among the pipes connected to the pressure vessel was completely broken and the coolant flowed into the pressure suppression chamber. . The heat removal capacity of the heat exchanger required when the residual heat removal equipment implements the emergency operation mode was designed under the assumption that the pool water from which heat is to be removed is 100° C. or less.

Patent Application Publication No. 58-4999

However, after the Great East Japan Earthquake, there is a need to consider the occurrence of a serious accident that exceeds the scale assumed so far. For this reason, it is being considered to assume that the upper limit temperature of pool water in the pressure suppression chamber is about 150°C, which exceeds the conventional 100°C. When the temperature of the pool water exceeds the initially assumed temperature (100° C.) in this way, the heat removal capacity of the heat exchanger is exceeded.

The above-described reactor auxiliary cooling equipment has a role of recovering waste heat from various equipment other than the heat exchanger of the residual heat removal equipment. When this heat exchanger operates in excess of its heat removal capacity, the cooling capacity of the reactor auxiliary cooling equipment is reduced. As a result, the cooling water supplied from the reactor auxiliary cooling system will exceed the rated temperature (35° C.), which may hinder the operation of various other equipment.

Originally, it would be desirable to review the design of these heat exchangers and reactor auxiliary cooling equipment to increase the heat removal capacity and cooling capacity. However, it is extremely difficult to make such modifications to existing nuclear reactor plants.

The embodiment of the present invention has been made in consideration of such circumstances, making maximum use of the existing equipment, and in the event of a serious accident, the containment vessel can be cooled quickly within a range that does not exceed the heat removal capacity of the heat exchanger. It is an object of the present invention to provide a residual heat removal technique capable of performing

The residual heat removal equipment according to the embodiment includes a thermometer that measures the temperature of the pool water held in the pressure suppression chamber provided in the containment vessel, a heat exchanger connected in parallel with each other, and a piping circuit provided with a bypass. a pump for flowing out the pool water held in the pressure suppression chamber to the piping circuit; and a residual heat removal facility for a nuclear power plant, wherein the flow rate of the pool water flowing out to the heat exchanger is an upper limit set in advance according to the water temperature when the measured water temperature exceeds a threshold adjusted so that the value is not exceeded.

The embodiment of the present invention provides residual heat removal technology that makes the most of existing facilities and can quickly cool the containment vessel within a range that does not exceed the heat removal capacity of the heat exchanger in the event of a severe accident.

1 is a circuit diagram of residual heat removal equipment according to a first embodiment of the present invention; FIG. FIG. 2 is a block diagram of the control unit of the residual heat removal equipment according to the first embodiment; Graph showing first correlation data and second correlation data. FIG. 4 is an explanatory diagram of the operation of the residual heat removal equipment according to the first embodiment; The circuit diagram of the residual heat removal equipment which concerns on 2nd Embodiment of this invention. The block diagram of the control part of the residual heat removal equipment which concerns on 2nd Embodiment. FIG. 11 is an operation explanatory diagram of the residual heat removal equipment according to the second embodiment and the third embodiment; The circuit diagram of the residual heat removal equipment which concerns on 3rd Embodiment of this invention. FIG. 11 is a block diagram of a control unit of residual heat removal equipment according to the third embodiment; Graph showing third correlation data. 4 is a flow chart of a method for operating residual heat removal equipment according to each embodiment.

(First embodiment)
An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a circuit diagram of residual heat removal equipment 10A (10) according to the first embodiment of the present invention. The residual heat removal equipment 10 of each embodiment includes a thermometer 37 for measuring the water temperature _Tp of the pool water 36 held in the pressure suppression chamber 35 provided in the containment vessel 25, and the heat exchangers 15 connected in parallel with each other. and a piping circuit 20 provided with a bypass passage 16, a pump 17 for flowing out the pool water 36 held in the pressure suppression chamber 35 to (the upstream side 20b of) the piping circuit 20, and a storage after flowing out to the piping circuit 20 and a flow meter 13 for measuring the total flow value F _a of the pool water 36 discharged into the container 25 .

Then, in the residual heat removal equipment 10 of each embodiment, when the measured water temperature T _p exceeds the threshold value T _h (T _h <T _p ; see FIGS. 4 and 7), the pool that flows out to the heat exchanger 15 The flow rate of the water 36 is adjusted so as not to exceed a preset upper limit according to the water temperature _Tp .

In each embodiment, the water temperature T _p of the pool water 36 is the temperature of the pool water 36 held in the pressure suppression chamber 35 that is measured. However, the measurement position of the water temperature T _p of the pool water 36 is not limited to this, and can be measured at any position on the pipe from the pressure suppression chamber 35 to the heat exchanger 15 .

In the residual heat removal equipment 10, at least one pump 17 and one heat exchanger 15 are connected to one piping circuit 20 to form a loop. there is In each valve provided in the piping circuit 20, the piping corresponding to the white display is in the open state, and the piping corresponding to the black display is in the closed state.

As shown in FIG. 1, a nuclear power plant 90 to which the residual heat removal equipment 10 of each embodiment is applied includes a pressure vessel 28 that hermetically accommodates a reactor core 24 and reactor water 23 that generate heat due to nuclear fission of nuclear fuel, the pressure vessel 28 and A containment vessel 25 that hermetically houses a control rod drive mechanism (not shown) and the like to prevent the release of radioactive materials, and a turbine that converts the thermal energy of steam generated by heating the reactor water 23 with the core 24 into rotational kinetic energy. (not shown), a generator (not shown) that converts this rotational kinetic energy into electrical energy, and a condenser (not shown) that cools and condenses the steam that has worked in the turbine to make condensate. have.

The pressure suppression chamber 35 is provided in the lower part of the containment vessel 25, and when the internal pressure of the pressure vessel 28 rises, steam is released to suppress the rise of the internal pressure. In addition, when a severe accident occurs and the pipe connecting the above-described equipment (not shown) and the pressure vessel 28 is broken, the reactor water 23 released from the broken pipe accumulates in the pressure suppression chamber 35 and pool water 36 . becomes. The pool water 36 is circulated inside or outside the pressure vessel 28 by the residual heat removal equipment 10 to submerge the core 24 or cool and condense the steam to suppress pressure rise.

The branch piping 48 of the piping circuit 20 is designed to keep the pool water 36 under pressure in order to prevent the core 24 from being exposed to the gas phase and overheating in the event of an accident in which the reactor water 23 flows out from the pressure vessel 28 into the containment vessel 25 . It is to be injected from the top of the container 28 . In this case, the regulating valves 18 and 19 are fully closed, the branch pipes 45 and 47 are closed, and the pool water 36 is injected into the pressure vessel 28 without heat removal by the heat exchanger 15 .

A dry well spray sparger 27 is connected to the downstream side 20 a tip of the piping circuit 20 . In the event of an accident in which the reactor water 23 flows out from the pressure vessel 28 into the containment vessel 25 , the reactor water 23 becomes steam and raises the temperature and pressure inside the containment vessel 25 . At this time, the regulating valve 18 is opened to discharge the pool water 36 from the drywell spray sparger 27, the temperature of the drywell space 26 is lowered, the steam is condensed, and the pressure rise is suppressed. Also, at this time, the regulating valve 18 of the branch pipe 46 may be opened to discharge the pool water 36 from the pressure suppression chamber spray sparger 44 .

A branch pipe 45 of the pipe circuit 20 is used when cooling the pool water 36 held in the pressure suppression chamber 35 . When the steam in the pressure vessel 28 is released to the pressure suppression chamber 35 during normal operation to suppress the pressure rise, the overheated pool water 36 is cooled. In this case, the regulating valves 18 and 19 are fully closed, the branch pipes 47 and 48 are closed, and the second on-off valve 12 connected to the bypass passage 16 is fully closed to remove heat from the pool water 36. inject.

A branch pipe 47 of the pipe circuit 20 is used for removing decay heat during normal operation and shutdown of the reactor. Reactor water 23 is taken from a reactor recirculation system (not shown), the heat is completely removed by the heat exchanger 15 , and then returned to the inside of the pressure vessel 28 . In this case, the regulating valves 18 and 19 are fully closed, the branch pipes 45 and 48 are closed, and the second on-off valve 12 connected to the bypass passage 16 is fully closed to remove heat from the pool water 36. inject.

The reactor auxiliary cooling facility 60 recovers waste heat from various facilities 61 (61a, 61b, 61c) of the nuclear power plant 90, including the heat exchanger 15 of the residual heat removal facility 10. These heat exchanger 15 and equipment 61 are connected to a cooling equipment 66 via a circulation path 65 through which cooling water 63 is circulated. The cooling equipment 66 uses seawater or the like as a coolant 68, and releases exhaust heat recovered from the heat exchanger 15 and the equipment 61 (61a, 61b, 61c) to the ocean or the like.

The cooling water 63 supplied to each of the heat exchanger 15 and the equipment 61 (61a, 61b, 61c) is connected to each of them, and the supply amount is adjusted by adjusting the flow control valve 62 (62a, 62b, 62c, 62d). is regulated. The cooling equipment 66 cools the cooling water 63 so that the initial temperature T _w does not exceed the rated temperature (35° C.). Further, the circulation pump 67 circulates the cooling water 63 so as to supply the cooling water 63 at the flow rate F _d required by the heat exchanger 15 and the flow rate required by the other equipment 61 .

FIG. 2 is a block diagram of the control section 50A of the residual heat removal equipment 10A according to the first embodiment, and FIG. 3 is a graph showing the first correlation data _D1 and the second correlation data _D2 . In this manner, the control unit 50A controls the water temperature T _p at which the amount of heat removed by the heat exchanger 15 is the limit when the bypass 16 (FIG. 1) is closed and the pool water 36 is allowed to flow out, and the upper limit value F is the first A first holding unit 51 holding the correlation data _D1 , a water temperature T _p at which the amount of heat removed by the heat exchanger 15 is limited when the bypass 16 is opened and the pool water 36 is allowed to flow out, and an upper limit value F. A second holding unit 52 holding the second correlation data _D2 , and the piping circuit 20 on the downstream side 20a (or upstream side 20b) of the heat exchanger 15 and the bypass 16 are provided to adjust the total flow rate value _Fa. An operation unit 38 that operates the regulating valve 18, a first on-off valve 11 that opens/closes the pool water 36 diverted to the heat exchanger 15, and a second on-off valve that opens/closes the pool water 36 diverted to the bypass passage 16. and a switching unit 39 for switching between 12 settings.

Further, the control unit 50A has a water temperature receiving unit 57 that receives measurement data of the water temperature T _p from the thermometer 37 and a total flow value receiving unit 58 that receives measurement data of the total flow value _Fa from the flow meter 13. are doing. The determination unit 54 determines the operation of the operation unit 38 and the switching unit 39 described above.

The first correlation data D ₁ indicates that the _amount of heat removed from the design is A total flow rate F _a that is the limit is obtained by performance calculation of the heat exchanger 15 . In the second correlation data _D2 , the amount of heat removed becomes the design limit with respect to the water temperature _Tp of the pool water 36 flowing into the heat exchanger 15 with the first on-off valve 11 and the second on-off valve 12 fully opened. Such a total flow rate value F _a is obtained by performance calculation of the heat exchanger 15 . As shown in FIG. 4, the first correlation data D ₁ is set so as to pass through the coordinates of the intersection of the threshold value T _h of the water temperature T _p and the rated value F _r of the pump flow rate value.

FIG. 4 is an operation explanatory diagram of the residual heat removal equipment 10A according to the first embodiment. When the water temperature T _p exceeds the threshold value T _h (T _h <T _p ), the control unit 50A of the first embodiment sets both the first on-off valve 11 (FIG. 1) and the second on-off valve 12 to open. . Then, the regulating valve 18 is operated so that the upper limit value F obtained by comparing the measured water temperature T _p with the second correlation data D ₂ is measured as the total flow rate value _Fa . Furthermore, the upper limit value _F obtained by collating the water temperature T _p at the time point P ₁ when the total flow rate value Fa reaches the rated value F _r of the pump 17 with the first correlation data D ₁ is measured as the total flow rate value F _a . Operate the regulating valve 18 so that

Furthermore, the setting of the second on-off valve 12 is switched from open to closed at the time point _P2 when the measured water temperature _Tp and the total flow rate value _Fa are on the first correlation data _D1 . Then, the regulating valve 18 is operated so that the upper limit value F obtained by comparing the measured water temperature T _p with the first correlation data D ₁ is measured as the total flow rate value _Fa . Then, at the time point P ₃ (T _p <T _h ) when the water temperature T _p no longer exceeds the threshold value T _h , the regulating valve 18 is operated so that the total flow rate F _a substantially coincides with the rated value F _r of the pump 17 . do.

In the above description of the first embodiment, an operation example in which only the regulating valve 18 is operated to adjust the total flow rate value _Fa was shown, but there is also an operation in which the regulating valve 19 of the branch pipe 46 is also operated. Alternatively, the pool water 36 may be circulated only in the heat exchanger 15 and the pressure suppression chamber 35 by adjusting the regulating valve of the branch pipe 45 without spraying by closing the regulating valves 18 and 19 .

Further, in the above description of the first embodiment, an operation example is shown in which both the first on-off valve 11 and the second on-off valve 12 are set to open when the water temperature T _p exceeds the threshold value T _h . However, in the first embodiment, an operation in which the first on-off valve 11 is always set to be open and the second on-off valve 12 is always set to be closed is also conceivable. In this case, the regulating valve 18 is operated so that the upper limit value F obtained by comparing the measured water temperature T _p with the first correlation data D ₁ is measured as the total flow rate value _Fa . Then, at the time point P ₃ (T _p <T _h ) when the water temperature T _p no longer exceeds the threshold value T _h , the regulating valve 18 is operated so that the total flow rate F _a substantially coincides with the rated value F _r of the pump 17 . do.

According to the first embodiment, by switching the first on-off valve 11 and the second on-off valve 12 to either "fully open" or "fully closed", a severe accident can be prevented without modifying the existing residual heat removal equipment 10. is generated, the containment vessel 25 can be quickly cooled while avoiding the heat removal capacity of the heat exchanger 15 from exceeding.

In this embodiment, the flow rate of the pool water 36 flowing out of the heat exchanger 15 is adjusted to the upper limit so that the amount of heat removed in the heat exchanger 15 reaches the design limit. From the viewpoint of the amount of heat removed by the heat exchanger, if it is lower than this upper limit, it does not have to match. From the viewpoint of cooling the pool water 36, it is desirable that the amount of heat removed in the heat exchanger 15 approximately matches the design limit.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a circuit diagram of residual heat removal equipment 10B according to the second embodiment of the present invention. FIG. 6 is a block diagram of the control section 50B of the residual heat removal equipment 10B according to the second embodiment. In FIG. 5, portions having the same configuration or function as in FIG. 1 or in FIG. 6 having the same configuration or function as in FIG.

As described above, the control unit 50B of the second embodiment has the first holding unit 51 holding the first correlation data D ₁ and the split flow rate value of the pool water 36 split to the heat exchanger 15, as in the first embodiment. A first operation unit 31 that operates the first adjustment valve 21 that adjusts _Fb , and a second operation unit 32 that operates the second adjustment valve 22 that adjusts the flow rate of the pool water 36 diverted to the bypass passage 16. I have.

Further, the control unit 50B includes, in addition to the water temperature _Tp receiving unit 57 and the total flow rate value _Fa receiving unit 58 described above, a divided flow rate value receiving unit 59 that receives measurement data of the divided flow rate value _Fb from the flow meter 29. have. The determination unit 54 determines the operations of the first operation unit 31 and the second operation unit 32 described above.

FIG. 7 is an operation explanatory diagram of the residual heat removal equipment 10B according to the second embodiment. When the water temperature T _p exceeds the threshold value T _h (T _h <T _p ) _, the control unit 50B of the second embodiment controls _the upper limit value F is measured as the divided flow rate value _Fb . Then, the second control valve 22 is operated so that the total flow rate value _Fa is measured as the rated value _Fr. Then, at the time point P ₄ (T _p <T _h ) when the water temperature T _p no longer exceeds the threshold value T _h , the first control valve 21 is fully opened and the second control valve 22 is fully closed, and the divided flow rate value F _b is approximately equal to the rated value _Fr.

According to the second embodiment, regardless of the water temperature T _p of the pool water 36 , the pool water 36 can be circulated through the piping circuit 20 by matching the total flow rate value F _a with the rated value F _r . As a result, when a severe accident occurs, the containment vessel 25 can be quickly cooled while avoiding an excess of the heat removal capacity of the heat exchanger 15 .

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a circuit diagram of residual heat removal equipment 10C according to the third embodiment of the present invention. FIG. 9 is a block diagram of the controller 50C of the residual heat removal equipment 10C according to the third embodiment. In FIG. 8, parts having the same configuration or function as those in FIG. 1 or 5 or in FIG. 9 having the same configuration or function as those in FIG.

Thus, the residual heat removal equipment 10C of the third embodiment includes the first opening meter 41 for detecting the first opening degree _A1 of the first regulating valve 21, the second opening degree of the second regulating valve 22 and a second opening meter 42 for detecting A ₂ . Then, the control unit 50C adjusts the flow rate of the pool water 36 branched to the first holding unit 51 holding the first correlation data and the heat exchanger 15 in the same manner as in the first embodiment or the second embodiment. A first operating unit 31 that operates the regulating valve 21, a second operating unit 32 that operates the second regulating valve 22 that adjusts the flow rate of the pool water 36 diverted to the bypass passage 16, and a total flow rate value F _a of the pump 17 and a third holding unit 53 that holds third correlation data _D3 between the first valve opening degree _A1 and the second valve opening degree _A2 measured as the rated value F _r of .

Further, the control unit 50C, in addition to the water temperature T _p receiving unit 57 and the total flow rate value F _a receiving unit 58, receives the first valve opening A from the first opening meter 41 and the second opening meter 42. ₁ and the second valve opening _A2 . The determination unit 54 determines the operations of the first operation unit 31 and the second operation unit 32 described above.

FIG. 10 is a graph showing third correlation data. The operation of the residual heat removal equipment 10C according to the third embodiment will be described with reference to FIGS. 7 and 10. FIG. When the water temperature T _p exceeds the threshold value T _h (T _h <T _p ), the control unit 50C of the third embodiment collates the measured water temperature T _p with the first correlation data D ₁ and determines the corresponding upper limit value F to get Then, the acquired upper limit value F is collated with the third correlation data _D3 , and the first control valve 21 and the second control valve are adjusted so that the corresponding first valve opening degree _A1 and second valve opening degree _A2 are obtained. 22 each. Then, at the time point P ₄ (T _p <T _h ) when the water temperature T _p does not exceed the threshold value T _h , the first valve opening degree A ₁ becomes 100% and the second valve opening degree A ₂ becomes 0%. , each of the first control valve 21 and the second control valve 22 is operated.

According to the third embodiment, without modifying the piping circuit 20, regardless of the water temperature _Tp of the pool water 36, the total flow rate value _Fa is made to match the rated value _Fr , and the pool water 36 is supplied to the piping circuit 20 can be circulated to As a result, when a severe accident occurs, the containment vessel 25 can be quickly cooled while avoiding an excess of the heat removal capacity of the heat exchanger 15 .

In the description of each embodiment, the first on-off valve 11, the second on-off valve 12, the first adjustment valve 21, the second adjustment valve 22, and the adjustment valves 18 and 19 are controlled by the control unit 50 (50A, 50B, 50C). An example of automatic control from However, these valves may also be remotely manually operated by an operator.

A method of operating the residual heat removal equipment 10 according to each embodiment will be described based on the flowchart of FIG. 11 (see FIG. 1 as appropriate). First, a threshold value T _h for performing determination is acquired (S11). The water temperature T _p of the pool water 36 held in the pressure suppression chamber 35 is measured by the thermometer 37 (S12).

When the measured water temperature T _p exceeds the threshold value T _h (S13 Yes), the bypass 16 is set to be open (S14) to divert the pool water 36, and the piping circuit 20 provided with the heat exchanger 15 is opened. The opening is set (S15) to divert the pool water 36 to remove heat.

When the water temperature T _p exceeds the threshold value T _h (Yes in S13), the specific driving operation is different in each embodiment and is as follows. In the first embodiment, the first correlation data D ₁ and the second correlation data D ₂ are referred to, and switching between the “fully open” and “fully closed” settings of the first on-off valve 11 and the second on-off valve 12 and the setting of the adjustment valve 18 are performed. operation. In the second embodiment, the split flow rate value _Fb of the pool water 36 diverted to the heat exchanger 15 is based on the first correlation data _D1 , and the total flow rate value _Fa substantially matches the rated value _Fr. , the first adjusting valve 21 and the second adjusting valve 22 are adjusted. In the third embodiment, the opening degrees of the first regulating valve 21 and the second regulating valve 22 corresponding to the water temperature _Tp of the pool water 36 are adjusted based on the third correlation data _D3 , and the total flow rate _Fa is set to the rated value. substantially match the value F _r .

Further, the measurement of the water temperature _Tp of the pool water 36 is continued (S16 No, S12), and when the measured water temperature Tp no longer exceeds the threshold _Th (S13 No), the bypass 16 is closed (S17). Then, the piping circuit 20 provided with the heat exchanger 15 is set to be open (S15), and the heat of the entire amount of the pool water 36 is removed. Then, when the containment vessel 25 is sufficiently cooled, the operation mode of the residual heat removal equipment 10 is terminated (S16 Yes, END).

According to the residual heat removal equipment of at least one embodiment described above, by opening/closing the bypass passage of the heat exchanger according to the water temperature of the pool water, the existing equipment can be utilized to the fullest extent and heat can be removed in the event of a serious accident. It is possible to quickly cool the containment vessel within a range that does not exceed the heat removal capacity of the exchanger.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

For example, the operator may read the measurement data of the water temperature and the flow rate, compare it with the data of the relationship between the upper limit value of the flow rate and the water temperature created in advance, and operate the valve. By operating the valve using data on the relationship between the upper limit of the flow rate and the water temperature, the operator can reliably control the amount of heat removed from the pool water 36 in the heat exchanger 15 so as not to exceed the design upper limit. Also, the upper limit value F is set so that the amount of heat removed by the heat exchanger 15 matches the design limit, but this is based on the design limit of the heat removal amount and the safety margin. It also includes the case where the upper limit value F is set corresponding to the amount of heat removed that is lower by the amount.

DESCRIPTION OF SYMBOLS 10 (10A, 10B, 10C)... Residual heat removal equipment, 11... 1st opening-and-closing valve, 12... 2nd opening-and-closing valve, 13... Flow meter, 14... Flow meter, 15... Heat exchanger, 16... Bypass path, 17 Pump 18 Regulating valve 20 Piping circuit 20a Piping circuit on the upstream side 20b Piping circuit on the downstream side 21 First regulating valve 22 Second regulating valve 23 Reactor water 24 Core 25 Containment vessel 26 Dry well space 27 Dry well spray sparger 28 Pressure vessel 31 First operation unit 32 Second operation unit 35 Pressure suppression chamber 36 Pool water , 37... thermometer, 38... operating unit, 39... switching unit, 41... first opening meter, 42... second opening meter, 44... pressure suppression chamber spray sparger, 45, 46, 47, 48... branch pipe , 50 (50A, 50B, 50C)...control section, 51...first holding section, 52...second holding section, 53...third holding section, 54...judgment section, 56...valve opening degree information receiving section, 57... Water temperature receiving unit 58 Total flow value receiving unit 59 Partial flow value receiving unit 60 Reactor auxiliary component cooling equipment 61 (61a, 61b, 61c) Other equipment 62 Flow control valve 63 cooling water, 65... circulation path, 66... cooling equipment,
67 Circulation pump 68 Refrigerant 90 Nuclear power plant T _p Water temperature T _h Threshold value F _a Total flow value F _b Partial flow value F _r Rated value D ₁ First correlation Data, D ₂ . . . second correlation data, P(P ₁ , P ₂ , P ₃ , P ₄ ) .

Claims (6)

a thermometer for measuring the temperature of the pool water held in the pressure suppression chamber provided in the containment vessel;
A piping circuit provided with a heat exchanger and a bypass channel that are connected in parallel with each other;
a pump that causes the pool water held in the pressure suppression chamber to flow out to the piping circuit;
a flow meter for measuring the total flow rate of the pool water discharged into the containment vessel after being discharged into the piping circuit ;
The residual heat removal equipment is adjusted so that the flow rate of the pool water flowing out to the heat exchanger does not exceed an upper limit set in advance according to the water temperature when the measured water temperature exceeds a threshold value. There is
a first holding unit that holds first correlation data between the water temperature and the upper limit value at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by closing the bypass;
a second holding unit that holds second correlation data between the water temperature and the upper limit value at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by opening the bypass;
an operation unit that operates an adjustment valve that is provided in the piping circuit on the upstream side or downstream side of the heat exchanger and the bypass passage and that adjusts the total flow rate;
a switching unit that switches settings of a first on-off valve that opens/closes the pool water that is diverted to the heat exchanger and a second on-off valve that opens/closes the pool water that is diverted to the bypass path,
when the water temperature exceeds the threshold, both the first on-off valve and the second on-off valve are set to open;
operating the regulating valve so that the upper limit value obtained by comparing the measured water temperature with the second correlation data is measured as the total flow rate value;
operating the regulating valve so that the upper limit value obtained by comparing the water temperature when the total flow rate reaches the rated value of the pump with the first correlation data is measured as the total flow rate;
Switching the setting of the second on-off valve from open to closed at the time when the measured water temperature and the total flow rate value are on the first correlation data,
operating the regulating valve so that the upper limit value obtained by comparing the measured water temperature with the first correlation data is measured as the total flow rate value;
A residual heat removal facility, wherein once the water temperature no longer exceeds the threshold, the regulating valve is operated such that the total flow value substantially corresponds to the rated value of the pump. a thermometer for measuring the temperature of the pool water held in the pressure suppression chamber provided in the containment vessel;
A piping circuit provided with a heat exchanger and a bypass channel that are connected in parallel with each other;
a pump that causes the pool water held in the pressure suppression chamber to flow out to the piping circuit;
a flow meter for measuring the total flow rate of the pool water discharged into the containment vessel after being discharged into the piping circuit ;
The residual heat removal equipment is adjusted so that the flow rate of the pool water flowing out to the heat exchanger does not exceed an upper limit set in advance according to the water temperature when the measured water temperature exceeds a threshold value. There is
a first holding unit that holds first correlation data between the water temperature and the upper limit value at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by closing the bypass;
a first operation unit that operates a first adjustment valve that adjusts a split flow rate value of the pool water that is split into the heat exchanger;
a second operation unit that operates a second adjustment valve that adjusts the flow rate of the pool water diverted to the bypass,
when the water temperature exceeds the threshold, operating the first regulating valve so that the upper limit value obtained by comparing the measured water temperature with the first correlation data is measured as the divided flow rate value;
operating the second control valve so that the total flow rate value is measured as the rated value of the pump;
Residual heat removal equipment, wherein when the water temperature no longer exceeds the threshold value, the first control valve is fully opened and the second control valve is fully closed so that the diversion flow rate value substantially matches the rated value. . a thermometer for measuring the temperature of the pool water held in the pressure suppression chamber provided in the containment vessel;
A piping circuit provided with a heat exchanger and a bypass channel that are connected in parallel with each other;
a pump that causes the pool water held in the pressure suppression chamber to flow out to the piping circuit;
a flow meter for measuring the total flow rate of the pool water discharged into the containment vessel after being discharged into the piping circuit ;
The residual heat removal equipment is adjusted so that the flow rate of the pool water flowing out to the heat exchanger does not exceed an upper limit set in advance according to the water temperature when the measured water temperature exceeds a threshold value. There is
a first holding unit that holds first correlation data between the water temperature and the upper limit value at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by closing the bypass;
a first operation unit that operates a first adjustment valve that adjusts the flow rate of the pool water diverted to the heat exchanger;
a second operation unit that operates a second adjustment valve that adjusts the flow rate of the pool water diverted to the bypass;
a first opening meter for detecting a first valve opening of the first regulating valve;
a second opening meter for detecting the opening of the second valve of the second control valve;
a third holding unit holding third correlation data between the first valve opening degree and the second valve opening degree for which the total flow rate value is measured as the rated value of the pump;
if the water temperature exceeds the threshold, comparing the measured water temperature with the first correlation data to obtain the corresponding upper limit;
operating each of the first control valve and the second control valve so that the acquired upper limit value is collated with the third correlation data and the corresponding first valve opening degree and the second valve opening degree are obtained;
When the water temperature no longer exceeds the threshold value, each of the first control valve and the second control valve is adjusted so that the degree of opening of the first valve is 100% and the degree of opening of the second valve is 0%. Residual heat removal equipment to operate. measuring the temperature of pool water held in a pressure suppression chamber provided in the containment vessel;
a step of pumping out the pool water held in the pressure suppression chamber into a piping circuit provided with a heat exchanger and a bypass passage that are connected in parallel with each other;
measuring the total flow value of the pool water discharged into the containment vessel after being discharged into the piping circuit;
adjusting the flow rate of the pool water flowing out to the heat exchanger not to exceed an upper limit value set in advance according to the water temperature when the measured water temperature exceeds a threshold value. In the residual heat removal method,
a step of preparing first correlation data between the water temperature and the upper limit at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by closing the bypass;
a step of preparing second correlation data between the water temperature and the upper limit at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by opening the bypass;
When the water temperature exceeds the threshold value, a first on-off valve that opens/closes the pool water diverted to the heat exchanger and a second on-off valve that opens/closes the pool water diverted to the bypass. setting open;
The piping circuit upstream or downstream of the heat exchanger and the bypass so that the upper limit value obtained by comparing the measured water temperature with the second correlation data is measured as the total flow rate value operating a regulating valve for regulating the total flow value provided in
The step of operating the regulating valve so that the upper limit value obtained by comparing the water temperature at the time when the total flow rate reaches the rated value of the pump with the first correlation data is measured as the total flow rate. and,
a step of switching the setting of the second on-off valve from open to closed when the measured water temperature and the total flow rate value are on top of the first correlation data;
a step of operating the regulating valve so that the upper limit value obtained by comparing the measured water temperature with the first correlation data is measured as the total flow rate value;
and, when the water temperature no longer exceeds the threshold, operating the regulating valve such that the total flow value substantially matches the rated value of the pump. measuring the temperature of pool water held in a pressure suppression chamber provided in the containment vessel;
a step of pumping out the pool water held in the pressure suppression chamber into a piping circuit provided with a heat exchanger and a bypass passage that are connected in parallel with each other;
measuring the total flow value of the pool water discharged into the containment vessel after being discharged into the piping circuit;
adjusting the flow rate of the pool water flowing out to the heat exchanger not to exceed an upper limit value set in advance according to the water temperature when the measured water temperature exceeds a threshold value. In the residual heat removal method,
a step of preparing first correlation data between the water temperature and the upper limit value at which the amount of heat removed by the heat exchanger becomes the upper limit value when the pool water is allowed to flow out by closing the bypass passage;
When the water temperature exceeds the threshold value, the upper limit value obtained by comparing the measured water temperature with the first correlation data is measured as the divided flow rate value of the pool water diverted to the heat exchanger. a step of operating a first regulating valve that adjusts this diversion flow rate;
operating a second regulating valve that adjusts the flow rate of the pool water diverted to the bypass so that the total flow rate value is measured as the rated value of the pump;
when the water temperature no longer exceeds the threshold value, the first regulating valve is fully opened and the second regulating valve is fully closed so that the divided flow rate value substantially matches the rated value. Residual heat removal method. measuring the temperature of pool water held in a pressure suppression chamber provided in the containment vessel;
a step of pumping out the pool water held in the pressure suppression chamber into a piping circuit provided with a heat exchanger and a bypass passage that are connected in parallel with each other;
measuring the total flow value of the pool water discharged into the containment vessel after being discharged into the piping circuit;
adjusting the flow rate of the pool water flowing out to the heat exchanger not to exceed an upper limit value set in advance according to the water temperature when the measured water temperature exceeds a threshold value. In the residual heat removal method,
a step of preparing first correlation data between the water temperature and the upper limit at which the amount of heat removed by the heat exchanger is limited when the pool water is allowed to flow out by closing the bypass;
A first valve opening degree of a first adjusting valve for adjusting the flow rate of the pool water diverted to the heat exchanger and the pool water diverted to the bypass passage, wherein the total flow rate value is measured as the rated value of the pump. a step of preparing third correlation data with the second valve opening of the second regulating valve that adjusts the flow rate of
if the water temperature exceeds the threshold, comparing the measured water temperature with the first correlation data to obtain the corresponding upper limit value;
A step of comparing the acquired upper limit value with the third correlation data and operating each of the first control valve and the second control valve so that the corresponding degrees of opening of the first valve and the degrees of opening of the second valve are obtained. and,
When the water temperature no longer exceeds the threshold value, each of the first control valve and the second control valve is adjusted so that the degree of opening of the first valve is 100% and the degree of opening of the second valve is 0%. A method for residual heat removal, comprising the step of operating.

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