JPH0545486A - Installation of control rod drive water - Google Patents

Abstract

PURPOSE:To obtain an installation for control rod drive water which enables an increase of tolerance in design of a condensate storage tank and reduction of the capacity of a building holding the condensate storage tank in a state wherein an effective suction head of a control rod drive pump is ensured equally. CONSTITUTION:In this installation, a control rod drive water tank 27 is provided and drive water pump 13 and a drive water piping 14 are connected to this water tank 27 through a control rod drive water system suction piping 34. Filters 33, 35 and 36 are provided for a condensate system return piping 10, a tank feed water piping 29 and a control rod drive water pump minimum flow piping 20 which are connected to the water tank 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control rod drive water facility used in a boiling water reactor plant.

[0002]

2. Description of the Related Art During normal operation, the control rod drive water equipment of a boiling water reactor plant uses a part of the return water from the condensate demineralizer of the condensate supply system to the condensate storage tank of the condensate makeup water system. Securing the amount of water supplied to the water pressure control unit during normal extraction and supplying purge water to the reactor recirculation pump and reactor coolant purification system pump. Further, since the return water from the condensate demineralizer stops during the periodic inspection, the control rod drive water pump is supplied from the condensate storage tank. During scram, the amount of return water from the condensate demineralizer is insufficient for normal operation.
Most of the water is supplied from the condensate storage tank regardless of the periodic inspection.

FIG. 3 shows a system configuration of a conventional control rod drive water facility and related condensate makeup water system and condensed water supply system. The condensate make-up water system uses the condensate storage tank 1 as a water source and is connected to the condensate storage tank 1 from the suction mother pipe 2 of the condensate make-up water system to the condensate transfer pump 3
Is used to supply water to the water supply load 6 via the condensate makeup water system water supply mother pipe 4 and the condensate makeup water system water supply pipe 5. This water supply load 6
There is also a main condenser 7 inside, and the water supplied to the main condenser 7 is treated by a condensate demineralizer 9 via a condensate system pipe 8 and then via a condensate system return pipe 10. It is a circulation loop that is returned to the condensate storage tank 1.

During normal operation, the control rod drive water equipment takes out a part of the return water through the control rod drive water supply pipe 23 connected to the condensate system return pipe 10 and joins the control rod drive water intake pipe 11 with it. , The control rod drive water pump 13 through the suction filter 12, is transferred to the water pressure control unit and the control rod drive mechanism 15 via the control rod drive water pipe 14, and is also supplied to the reactor recirculation pump purge water pipe 16 and the reactor cooling. Purging water is supplied to the reactor recirculation pump 17 and the reactor coolant cleaning system pump 19 via the material purification system purge water pipe 18.

During normal purging, the flow rate required for the control rod drive water pump 13 is small, so most of the water is supplied from the control rod drive water pump minimum flow pipe 20 to the control rod drive water heater pipe. The circulation operation is branched to 21 and returned to the control rod drive system suction pipe 11 while being heated by the control rod drive water heater 22. This is to prevent dew condensation on the control rod drive water system piping inside the reactor containment, and should be installed on the control rod drive water pump minimum flow pipe 20 when the system water temperature rises too much due to circulation operation. Open the discharge valve 24 to return the hot system water to the condensate storage tank 1.

On the other hand, during the periodical inspection, the return water from the condensate demineralizer 9 is stopped, so that the water source of the control rod drive water equipment is the condensate storage tank 1 and is connected to the condensate makeup water system suction mother pipe 2. Directly taken out from the control rod drive system suction pipe 11 and joined to the control rod drive water system suction pipe 11 in the same manner as during normal operation and then through the suction filter 12 to the water pressure control unit and control rod drive mechanism 15 with the control rod drive pump 13. Along with the transfer, the reactor recirculation pump purge water pipe 16 and the reactor coolant purification system pump purge water pipe 18
17, Purge water is supplied to the reactor coolant purification system pump 19.

[0007]

Generally, the effective suction head of a pump is given by the first equation. Among these, the factors contributing to the plus side are the atmospheric pressure and the hydrostatic head difference, but since the atmospheric pressure is constant, the pump If the required suction head is large and it is necessary to secure an effective suction head, it is necessary to increase the hydrostatic head difference to increase the effective suction head.

On the other hand, the factors contributing to the negative side are the saturated vapor pressure and the pipe pressure loss, but the saturated vapor pressure has a small effect on the effective suction lift, and it is necessary to reduce the pipe pressure loss when increasing the effective suction lift. There is. Effective suction head = atmospheric pressure-saturated vapor pressure + hydrostatic head difference-pipe pressure loss (1)

In the case of a control rod drive water pump, the required suction lift of the pump is large, and the condensate storage tank, which is the water source at the time of scram in the pump design mode, is set to a somewhat high position so that the hydrostatic head difference is small. It is necessary to increase the effective suction head to make it larger.

The water condensate storage tank serves as a water source for the condensate transfer pump, the high pressure core spray pump, the reactor isolation cooling system pump, etc. in addition to the control rod drive pump. The pump head is the largest, and this often determines the minimum installation level of the condensate storage tank. Therefore, as shown in FIG. 4, the condensate storage tank 1 is installed at a high position of the building 30 in which it is housed, and unnecessary dead space is increased in the condensate storage tank lower floor 31, while the condensate storage tank upper floor is increased. In the case of 32, the condensate storage tank 1 rises up and is chased further upward, which effectively enlarges the building volume and is not desirable in terms of layout and economy.

In order to reduce the pressure loss of the piping, it is necessary to reduce the pressure loss of the suction filter that occupies most of the pressure loss. However, in order to reduce this pressure loss, it is necessary to remove the suction filter. It is necessary to consider a method of filtering system water instead of a filter.

The present invention has been made in order to solve the above-mentioned problems. With the effective suction lift of the control rod drive pump secured as in the conventional case, the condensate storage tank is designed with a wider margin and An object of the present invention is to provide a control rod drive water facility capable of reducing the volume of a building that houses a water storage tank.

[0013]

According to the present invention, a condensate storage tank is connected to a water intake system suction mother pipe, a condensate transfer pump is connected to the water supply system suction mother pipe, and a control rod is connected to the condensate storage tank. In the control rod drive water facility where the drive water system suction pipe is connected and the drive pump and the drive water pipe are connected to this suction pipe, a control rod drive water tank is provided, and the control rod drive water system suction pipe is installed in this control rod drive water tank. The drive water pump and the drive water pipe are connected through a pipe, and a filter is installed on the condensate return pipe connected to the drive water tank, the tank water supply pipe, and the control rod drive water pump minimum flow pipe. Is characterized by.

[0014]

[Operation] By installing a dedicated drive water tank at a height that satisfies the required suction head of the control rod drive water pump, the condensate storage tank can be arranged regardless of the control rod drive water facility.
By using this driving water tank as a water source, the driving water pump can be provided with a necessary pushing pressure as in the conventional case.

Further, by removing the suction filter from the suction arrangement, the pipe pressure loss is greatly reduced.
The installation level of the driving water tank can be further increased. The function of filtering system water by removing the suction filter is to install a filter of the same capacity as the suction filter in all inflow pipes to the drive water tank, which is the water source, to drive clean system water as before. Can be supplied to.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the control rod drive water equipment according to the present invention will be described below with reference to FIGS. In addition,
In the figure, the same parts as those of the conventional example shown in FIGS.

That is, the control rod drive water equipment of the embodiment shown in FIG. 1 is provided with a dedicated control rod drive water tank 27 instead of receiving water from the condensate storage tank 1 and the condensate system return pipe 10 which are conventional water sources. The control rod drive water system suction pipe 34 connected to the drive water tank 27 receives water supply.

Specifically, the water flow is controlled from the control rod drive water tank 21 through the control rod drive water system suction pipe 34 regardless of the normal operation, the periodic inspection, and the scrum.
Supplied to 13.

The water pressurized by the control rod driving water pump 13 is connected to the control rod driving water pipe 14 to a water pressure control unit.
It is supplied to the control rod drive mechanism 15 and is purged to the reactor recirculation pump 17 and the reactor coolant purification system pump 19 by the reactor recirculation pump purge water pipe 16 and the reactor coolant purification system pump purge water pipe 18, respectively. Supply water.

During the normal purging operation, the required flow rate is small with respect to the capacity of the control rod drive water pump 13. Therefore, most of the water branches from the control rod drive water pump minimum flow pipe 20 to the control rod drive water heater pipe 21 and is returned to the control rod drive water system suction pipe 34 while being heated by the control rod drive water heater 22. It is driving. This is to prevent dew condensation on the control rod drive water system piping inside the reactor containment vessel. Also, if the system water temperature rises too much due to circulation operation, control rod drive water pump minimum flow piping 20
The discharge valve 24 installed above is opened to return the hot system water to the control rod drive water tank 27 through the filter 36.

Next, the control rod drive water tank in this embodiment
27 The action of the surroundings is shown. Return water from the condensate demineralizer 9 is supplied to the control rod drive water tank 27 through the filter 33 through the condensate return pipe 10. Similarly, the return water from the radioactive waste treatment facility 25 is also supplied to the control rod drive water tank 27 via the filter 33 by the waste treatment facility return pipe 26.

At the time of normal operation and at the time of periodic inspection, the amount of water used in the control rod drive water equipment is very small, and the amount of water entering the control rod drive water tank 27 is greater than the amount of water entering it. In many cases, the capacity of the control rod drive water tank 27 is over. Therefore, the control rod drive water tank 27
The overflow level is provided with an overflow pipe 28 and the transfer destination is the condensate storage tank 1. As a result, most of the return water other than the water used in the control rod drive equipment is returned to the condensate storage tank through the control rod drive water tank 27 and the overflow pipe 28, and finally to the condensate storage tank as in the conventional method. The functions of the condensate makeup water system and the high-pressure core spray system using the tank 1 as a water source are maintained as in the conventional case.

Even during the scrum, during normal operation, the condensate demineralizer return water, which is larger than the required capacity of the control rod drive equipment, is continuously supplied to the control rod drive water tank 27 of the water source. The control rod drive water facility functions as before. In the scrum (0 scrum) under regular inspection, the condensate demineralizer return water is stopped, but the control rod drive water tank
27 has a certain capacity, the return water of the radioactive waste treatment facility, which is the other water source, can be expected, and it can be replenished from the condensate replenishment water system by the tank water supply pipe 29 through the filter 35. Can be maintained.

As described above, by installing the control rod drive water tank 27 dedicated to the control rod drive water equipment, the effective suction lift of the control rod drive water pump 13 becomes sufficiently large, and the condensate storage tank 1 which is the conventional water source is provided. It is possible to operate regardless of the installation level.

FIG. 2 shows the condensate storage tank 1 in the above embodiment,
An outline of a sectional view of a building in which the control rod driving water tank 27, the control rod driving water pump 13 and the like are housed is shown. As is clear from FIG. 2, in this embodiment, the water source is installed as the dedicated control rod drive water tank 27 so as not to be affected by other facilities, so that the effective suction head of the control rod drive water pump 13 is higher than that of the conventional one. Can be secured. Further, since there is no restriction on the effective suction lift of the control rod drive water pump 13, it is possible to keep the floor height of the condensate storage tank lower floor 31 low by the amount that the installation position of the condensate storage tank 1 can be lowered. .. Furthermore, as much as the condensate storage tank 1 has moved to a lower position, the upper floor of the condensate storage tank 32
Since it can also be moved downward, the volume of the building 30 is reduced as a whole and the economy is improved.

Further, by installing filters 33, 35 and 36 in all the inflow pipes to the control rod drive water tank 27 and keeping the downstream side from the drive water tank 27 clean, the suction filter 12 which accounts for most of the pipe pressure loss. Can be deleted, and the effective suction head of the control rod drive water pump 13 is increased, so that the latitude of the installation location of the drive water tank 27 is further increased.

[0027]

According to the present invention, by providing a dedicated control rod driving water tank, the effective suction lift of the control rod driving pump is maintained as in the conventional case, and the condensate storage which is the conventional water source is stored. There is no connection with the tank. Therefore,
The restriction on the control rod drive water pump given to the design of the condensate storage tank is removed, the margin of the design of the condensate storage tank is increased, and as a result, the economy of the building for housing the condensate storage tank is reduced, thereby improving the economic efficiency. Contribute.

Further, by disposing a filter in all the inflow pipes to the control rod drive water tank, the system water of the control rod drive water equipment from the drive water tank to the drive water pump can be kept clean, and the pipe pressure loss It is possible to eliminate the suction filter that occupies most of the above, which increases the effective suction head of the driving water pump and increases the latitude of the installation position of the driving water tank.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a control rod drive water facility according to the present invention.

FIG. 2 is a vertical sectional view schematically showing the interior of a main part of FIG.

FIG. 3 is a system diagram showing a conventional control rod drive water facility.

FIG. 4 is a vertical cross-sectional view schematically showing the interior of a main part of FIG.

[Explanation of symbols]

1 ... Condensate storage tank 2 ... Condensate makeup water system suction mother pipe 3 ... Condensate transfer pump 4 ... Condensate makeup water system water supply mother pipe 5 ... Condensate makeup water system water supply pipe 6 ... Water supply load 7 ... Main condenser 8 ... Condensate system piping 9… Condensate demineralizer 10… Condensate system return piping 11,34… Control rod drive water system suction pipe 12… Suction filter 13… Control rod drive water pump 14… Control rod drive water pipe 15… Water pressure control unit control Rod drive mechanism 16… Reactor recirculation pump purge water piping 17… Reactor recirculation pump 18… Reactor coolant purification system pump purge water piping 19… Reactor coolant purification system pump 20… Control rod drive water pump minimum flow Pipe 21 ... Control rod drive water heater pipe 22 ... Control rod drive water heater 23 ... Control rod drive water supply pipe 24 ... Discharge valve 25 ... Radioactive waste treatment facility 26 ... Waste treatment facility return pipe 27 ... Control rod drive Water tank 28… Overflow piping 29… Tank water supply piping 30 Building 31 ... condensate storage tank bottom floor 32 ... condensate storage tank upper floor 33,35,36 ... filter

Claims (1)

[Claims] 1. A condensate storage tank is connected to a water supply system suction mother pipe, and a condensate transfer pump is connected to this water supply system suction mother pipe.
A control rod drive water tank is provided in a control rod drive water facility in which a control rod drive water system suction pipe is connected to the condensate storage tank, and a drive water pump and a drive water pipe are connected to the suction pipe. The drive water pump and the drive water pipe are connected to the drive water tank via the control rod drive water system suction pipe, and the condensate return pipe, the tank water supply pipe, and the control rod drive water pump minimum connected to the drive water tank A control rod drive water facility characterized by being equipped with a filter in the flow pipe.