JPH10197686A - Reactor power plant and its operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress to minimum the generation quantity of waste of filtering assistant and efficiently purify condensate. SOLUTION: In a condensate filtering device 6, A filtering tower group 12 having pleats type filter element and B filtering tower group 14 having hollow fiber membrane type element are connected in parallel to each other. By separately using the towers of A filtering tower group 12 and B filtering tower group 14 before startup of plant, the condensate condensed in a condenser 5 can be washed desirably and insoluble impurity and soluble impurity can be removed better than that using only powder resin precoat type or only hollow fiber membrane type so that condensate before startup of the plant can be efficiently washed. Therefore, the condensate demineralization device can surely be prolonged in life and reduction of operation cost can be planned that much.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling water nuclear power plant and a method of operating the same, and more particularly to a condensate system having a condensate filtration device for purifying primary condensate and a condensate desalination device. The present invention relates to a power plant suitable for use.

[0002]

2. Description of the Related Art Generally, a boiling water nuclear power plant is
As shown in FIG. 9, power is generated by circulating light water. That is, the condensed water flowing into the reactor 2 from the water supply system 1 is partially vaporized by the fuel 3, and the vapor is extracted and guided to the turbine 4. The steam that has driven the turbine to perform work is condensed in the condenser 5 to be condensed. Here, the condenser 5 reacts with the steam to corrode and generate insoluble impurities mainly composed of iron. When a large amount of this insoluble impurity flows into the reactor 2, it accumulates in a form containing radioactivity on the surface of the internal structure in various places, causing an increase in the exposure of workers during work. know.

Therefore, in order to reduce the impurities brought into the reactor 2 as much as possible, it is necessary to remove the impurities by any method between the condenser 5 and the water supply system 1. The condensate containing impurities condensed in the condenser 5 is first passed through a condensate filtration device 6, and the insoluble impurities are removed by the cover filtration device 6. Next, water is passed through a condensate desalination device 7 to remove soluble impurities with an ion exchange resin in the device 7.
The temperature is raised and pressurized through a water supply pump 9 and a high-pressure water heater 10 and supplied to the reactor 2.

[0004] The condensate filtration device 6 can be roughly classified into a so-called powdered resin precoat type filtration tower in which a filtration element is coated with a powdered ion exchange resin (filtration aid), and a hollow fiber membrane filter using no filter aid. There were two types: a type filtration tower.

The powdered resin precoat type filtration tower has a structure as shown in FIG. 5, in which a conductor 22 having a condensate inlet pipe 20 and a treated water outlet pipe 21 is provided at a lower part, and a flange bolt is provided at an upper part of the conductor 22. Cover plate 23 attached by 24
, An element 25, a tube sheet 26 for holding the element 25 inside the body plate 22, and a treated water outlet pipe 2.
And a rectifying plate 27 disposed upstream of the rectifying plate 27.

There are various types of the element 25, such as a wound nylon thread, a metal wire mesh and a wedge wire structure. The gap through which the treated water flows has a size of several tens of μm. Since the particle size of the insoluble impurities of the condensed water to be filtered is distributed in a size of about 1 to 10 μm, the surface of the element 25 is coated with an ion exchange resin as a filter aid (this is Pre-coat)
use.

In this condensate filtration apparatus of the powder resin precoat type, condensate enters the inside of the body plate 22 through the treated water inlet 20 through the tube sheet 26 as shown by the arrow a, and passes through the element 25 from the inside. , Powder ion exchange resin layer 2
After the soluble impurities are chemically ion-exchanged by 8 and the soluble impurities are physically filtered, they pass downward through the element 25 as shown by the arrow b, and then pass through the rectifying plate 27 as shown by the arrow c. The water is returned from the treated water outlet pipe 21 to the condensate system.

When the specified amount of impurities is filtered in this way, backwashing is performed by flowing water in the reverse order of the arrow, and then the ion-exchange resin layer 28 and impurities are removed from the element 25.
And discharged to the outside of the tower. The ion-exchange resin layer 28 and impurities discharged from this tower are concentrated by a waste treatment device, and then incinerated or drummed. The backwashed filtration tower is newly precoated with the ion exchange resin layer 28 on the surface of the element 25, and is subjected to the condensate treatment again.

On the other hand, hollow fiber membrane filter type filtration towers are disclosed in, for example, JP-A-49-976, JP-A-56-76208, and JP-A-59-4403. As shown in FIG. 6, a main body 31 provided with a condensate inlet 32 at a lower part and a treated water outlet 33 at an upper part, a hollow fiber membrane module 35 composed of a plurality of pieces, and a holding member 36 holding a plurality of the modules 35 are provided. have.

The hollow fiber membrane module 35 is formed by filling a housing with a bundle of several thousand hollow fiber membranes 34 each having an outer diameter of about 1 mm, and the surface of the hollow fiber membrane 34 has a thickness of 1 μm.
There are small holes of about 0.1 μm. This hole is
Since it is sufficiently smaller than the particle size of the impurities in the condensate, no filter aid is required, and only the insoluble impurities in the condensate are physically removed.

In this hollow fiber membrane filter type, when condensate flows into the hollow fiber membrane module 35 from the condensate inlet pipe 32 as shown by the arrow, insoluble impurities are removed by the hollow fiber membrane 34 in the process. The treated water flows upward in the hollow fiber membrane module 35 and returns from the treated water outlet 33 to the condensate system.

[0012] When a predetermined amount of impurities is filtered in this way, back washing is performed. In this case, the back washing is performed by washing the membrane surface with a stream of air bubbles. The backwash waste liquid contains only the impurities collected from the condensate.

[0013] In addition to these two types of filtration devices, a pleat-type element 41 as shown in FIG. 7 has recently been developed and is currently in a test stage. The element is configured by processing the microfiltration membrane 42 into a pleated shape. This pleated element has a membrane surface of about several μm and can be used in a pre-coated state, and can be backwashed.

The above-described various filtration devices are individually installed as a plurality of condensate filtration devices. Incidentally, those related to this type of device include, for example,
-310710 and the like.

[0015]

The prior art condensate filtration devices shown in FIGS. 5 and 6 have been used alone, and therefore have the following problems.

That is, the powder resin precoat type shown in FIG. 5 uses the ion-exchange resin layer 28 as a filter aid, so that it is excellent in purifying soluble impurities. Therefore, the purification performance of insoluble impurities is unstable. In addition, the use of filtration aids generates waste after use, especially in boiling water reactor power plants that directly purify the steam generated from the reactor,
Since the waste is treated as waste containing radiation, there is a problem that the treatment cost is high.

The hollow fiber membrane filter type shown in FIG. 6 is excellent in purification of insoluble impurities because it is physically filtered by pores provided on the membrane surface. As shown in FIG. 9, it was necessary to perform purification by a condensate desalination device 7 installed downstream of the condensate filtration device 6. In particular, at the time of purification before starting the plant, since the condensate is open to the atmosphere, the carbon dioxide dissolved in the condensate from the atmosphere consumes the ion exchange capacity of the ion exchange resin in the condensate desalination unit 7, The event that the conductivity of the condensed water does not reach the specified value, or even the required ion exchange capacity at the time of seawater leak, has been consumed, resulting in the necessity of urgently changing the exchange resin.

During the rated output operation of the plant, since the condenser 5 has a function of degassing steam, there is no problem of carbon dioxide gas and the generation of insoluble impurities is extremely small. In this case, there is no need for the condensate filtration device to have a function of purifying soluble impurities.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to minimize the amount of filter aid generated as waste and to efficiently purify condensate before starting the plant. It is an object of the present invention to provide a nuclear power plant that can maintain the exchange resin of the condensate desalination apparatus healthy, and a method of operating the nuclear power plant.

[0020]

In a nuclear power plant according to the present invention, a condensing filter is connected to a condensing pipe in parallel with each other, and at least a first condensing filter having a pleated filter element is provided. It is characterized by comprising a water filtration tower and a second condensate filtration tower having a filtration element of a hollow fiber membrane type.

In the method for operating a nuclear power plant of the present invention, A) a first pleated condensate comprising a filter element pre-coated with an ion exchange resin and a filter element not pre-coated with an ion exchange resin is selectively mounted. A condensate filtration device in which a filtration tower and a condensate filtration tower having a filtration element of a hollow fiber membrane type are connected in parallel to a condensate pipe beforehand; B) A filtration element precoated with an ion exchange resin is used. The first step in which water is passed through the installed first condensate filtration tower while the condensate is not passed through the second condensate filtration tower, and the first condensate is equipped with a filtration element pre-coated with ion exchange resin. The second step in which water is passed through the water filtration tower and the second condensate filtration tower, and the first condensate in which a filtration element that is not precoated with ion exchange resin is installed. The third step of passing water through the supercondenser and the second condensing filtration tower, and the fourth step not passing water through the first condensing filtration tower, but passing water only through the second filtration tower, And is selectively executed in accordance with the state before starting and during the operation of the plant.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In the nuclear power plant according to the embodiment, as shown in FIG. 1, steam generated in the reactor 2 is extracted, and the extracted steam drives the turbine 4 to perform work, and then is condensed in the condenser 5. The condensed water is pressurized by a condensate pump 11, passes through a condensate filtration device 6 according to the present invention, and enters a condensate desalination device 7 where soluble impurities are removed. Removed, then water system 1
Low temperature feed water heater 8, water feed pump 9, high temperature feed water heater 1
Water is supplied to the reactor 2 which has been pressurized and heated through 0.

Accordingly, the reactor 2, a water supply system 1 for supplying water to the reactor 2, a turbine 4 driven by steam extracted from the reactor 2, and condensing steam from the turbine 4 to condense water And a condensate system for purifying the condensed water. The condensate system includes a condenser 5, a condensate pump 11, a condensate filtration device 6, and a condensate desalination device 7. ing.
In the condensate system, the condensate filtration device 6 has a plurality of filtration towers connected in parallel.

Here, the condensate filtration device 6 is roughly composed of a group of A filtration towers 12 and a group of B filtration towers 14.

The A filtration tower group 12 in this embodiment is composed of two filtration towers as shown in FIG. 1, and each filtration tower is equipped with a pleated filtration element inside. That is, although not shown in FIG. 1, this filtration element is selected from those having a surface precoated with an ion exchange resin with a filter aid and those not having the ion exchange resin precoated. When a precoated filtration element is used, an ion exchange resin is precoated by a worker in the precoating facility 20, and the precoated filtration element is mounted on a filtration tower. Therefore, A
Each of the filtration towers of the filtration tower group 12 is selectively equipped with a pre-coated filtration element and a non-pre-coated filtration element.

Each of the B filtration tower groups 14 is constituted by a hollow fiber membrane filter type, and in this embodiment, comprises six units.
These filtration towers are connected in parallel to the condensate piping.

As shown in FIG. 2, on the upstream side of each of the filtration towers 12 and 14, there are provided flow control valves 13 and 15, respectively, which can control the flow rate of the condensed water flowing therethrough. By selectively opening and closing the valves 13 and 15, the condensed water is made to pass through a desired filtration tower. In FIG. 2, flow control valves 13 and 15 are provided on the upstream side of each of the A filtration tower group 12 and the B filtration tower group 14, but actually, as shown in FIG. Valves 13A and 15A are also provided on the side.

As described above, when the condensate filtration device 8 having the A filtration tower group 12 and the B filtration tower group 14 is operated, it is configured to be properly used according to the four operation modes.

Next, according to the operation mode, the A filtration tower group 1
An embodiment of an operation method in which the fuel cell 2 and the B filtration tower group 14 are properly used will be described. For example, each column of the A filtration tower group 12 is precoated with an ion-exchange resin, and the flow control valve 13 is opened to allow the condensate water to flow from the condensate pump 11 to the precoated A filtration tower group 12. On the other hand, the flow control valve 15 is closed so that the condensate does not flow through each column of the B filtration tower group 14. This is called operation mode 1 and is shown in FIG.

The operation mode 1 is used when the conductivity of the condensed water is significantly higher than a specified value by carbon dioxide or an ionic rust preventive applied to each device before the plant is started, or when the plant is started. This is performed when it is necessary to achieve the specified water quality in a short period of time, such as immediately before, etc. Water quality can be reached. Therefore, by performing this processing before starting the plant, the condensed water can be purified.

Further, as shown in FIG.
Using a pre-coated ion-exchange resin in the column A, a flow control valve 13
Is opened to allow the condensate to pass, and the water is also passed to the towers of the filtration tower group 14. This is called operation mode 2.

This operation mode 2 is used before starting the plant and in a state where the conductivity of the condensed water substantially satisfies the specified value, when it is desired to mainly purify insoluble impurities, or when the output of the plant is increased. This is executed when the deaeration function of the vessel 5 starts to work, and a part of the condensate is passed through the precoated filtration tower, and the condensate is partially ion-exchanged and the remaining amount of the condensate is removed. Is passed through a B filtration tower, whereby insoluble impurities can be efficiently removed from the remaining condensate.

However, in this case, the A filtration tower group 12 and the B filtration tower group 14 can meet the requirements by changing the distribution ratio of the condensed water flow rate by appropriately adjusting the opening of the flow control valves 13 and 15. A corresponding removal can be performed. For example, when the emphasis is placed on the removal of insoluble impurities, the opening of the flow control valve 13 may be further opened as compared with the case where the condensate flow rate is half the flow rate. . If the emphasis is placed on the removal of soluble impurities, the opposite may be performed.

In the operation mode 3, as shown in FIG. 3, an ion exchange resin which is not pre-coated on the A filtration group 12 is used.
2 is opened to allow the condensate to flow and the B filter group to flow. In this operation mode 3, since water flows through the group A of filtration towers 12 of ion exchange resin which is not pre-coated and also flows through the group B of filtration towers B of a hollow fiber membrane filter type, the condensate is dissolved after the plant output rises. This is performed when the concentration of the sexual impurity is low and when the insoluble impurity is removed.

Further, in the operation mode 4, water is not passed through the A filtration tower group 12, but is passed through the hollow fiber membrane filter type condensate filtration tower. This operation mode 4 is executed when it is desired to remove insoluble impurities brought into the nuclear reactor 2 as much as possible irrespective of the state of the plant such as start-up and rated operation.

In the method of the present invention, as described above, the A filter tower group 12 and the B filter tower group 14 of different types are used, and these are independently controlled according to the condensed state before the plant is started or the state during operation. A filtration tower group 12
Since a filtration element that does or does not have an ion-exchange resin to be used is attached, the function of removing condensate can be arbitrarily changed. For this reason, the condensed water before the start of printing can be reliably purified, so that the soundness and operation rate of the plant can be improved.

Further, in the plant of the embodiment, the condensate filtration device 6 has the A filtration tower group 12 having pleated elements.
And a group of B filtration towers 14 having a hollow fiber membrane type element are connected in parallel with each other.
By properly using each tower of the filtration tower group 12 and each tower of the B filtration tower group 14, desired washing can be performed on the condensed water condensed by the condenser 5, as in the prior art. Compared to those using only the powder resin precoat type or those using only the hollow fiber membrane type, it is possible to remove insoluble impurities and also to remove soluble impurities. The condensate can be efficiently washed. Therefore, the condensate before the start of the plant can be efficiently washed, so that the life of the condensate desalination apparatus can be reliably prolonged, and the operating cost can be reduced accordingly.

Further, in the filtration tower used for the A filtration tower group 12, the filtration element pre-coated with the ion exchange resin and the filtration element not pre-coated with the ion exchange resin are selectively mounted. If an ion exchange resin is used, the generation of waste can be suppressed as much as possible, and the processing cost can be reduced as compared with a conventional example using a condensate filtration device using only a powder resin precoat type.

FIG. 4 shows another embodiment of the present invention.
By the way, as described above, when the A filtration tower group 12 and the B filtration tower group 14 of different types are provided as the condensate filtration device 6, when water is passed through these, there is a characteristic that the pressure loss is different.

FIG. 8 shows the operation time and the change of the filtration differential pressure when water is passed through and washed through the filtration tower repeatedly. The horizontal axis represents the operation time, and the vertical axis represents the inlet pipe and the outlet pipe. It represents the pressure difference of the contained fluid. Curve A in the figure shows the change with time of the differential pressure of the hollow fiber membrane type, curve B shows the change with time of the differential pressure of the filtration tower precoated with the ion exchange resin, and curve C shows the difference with the filtration tower without the precoating of the ion exchange resin. The changes over time with pressure are shown.

In the figure, in the curve a, the increase in the differential pressure with respect to time increases almost linearly, and the same differential pressure form is again obtained after the cleaning step a '. The curve b has a characteristic that the expected value is lower than that of the curve a and increases linearly from there, and increases exponentially at the inflection point b ′. As a result, a similar differential pressure form is obtained. Curve C has almost the same form as Curve B, but has a feature that it is slightly lower than expected at Curve B, and increases one-hourly from there, and has a larger differential pressure rise than Curve B. I can understand.

Then, the flow rate of water passing through each of the towers is inversely dependent on each filtration pressure difference. In other words, while the flow rate of water increases in a filtration tower with a low differential pressure, the flow rate of water decreases in a filtration tower with a high differential pressure, causing uneven flow rates on both sides. Therefore, it is necessary to provide the flow control valves 13 and 15 to control the flow rate of each filtration tower. That is, the flow control valve 1
By adjusting the openings of 3, 15 the flow rate of water through each filtration tower can be adjusted. Therefore, it is necessary to detect the differential pressure in order to adjust the openings of the flow valves 13, 15.

Therefore, in the embodiment, as shown in FIG.
A differential pressure detector 16 for detecting the differential pressure between the upstream and downstream of each filtration tower in the A filtration tower group 12, and a differential pressure detector 17 for detecting the upstream and downstream differential pressure of each filtration tower in the B filtration tower group 14 And is installed. Output portions of the differential pressure detectors 16 and 17 are connected to a valve opening adjuster 18 that can control the flow control valves 13 and 15. The valve opening adjuster 18 has a calculation function, and adjusts the opening of the flow control valves 13 and 15 based on the calculation result.

For example, when the condensate filtration device 6 is operated in the operation mode 2, that is, the ion exchange resin precoated on the tower of the A filtration tower group 12 is used, and the precoated A is used.
When the flow rate control valve 13 is opened to allow the condensate to pass through the filtration tower group 12 and the water is also passed through the tower of the filtration tower group 14, the removal function of the precoated ion exchange resin reaches a saturated state, For this reason, since the condensed water becomes difficult to flow, the curve B is in the state of the inflection point B '. When this is detected by the differential pressure detector 16, the valve opening adjuster 18 calculates and calculates the difference between the differential pressures. A signal for reducing the degree of opening is output to the flow control valve 15 of the B filtration tower group 14, and the flow rate of water flowing through the B filtration tower group 14 is reduced.

As a result, the flow rates of the pre-coat type A filtration tower group 12 and the hollow fiber membrane type B filtration tower group 14 are kept uniform, so that the A filtration tower group 12 and the B filtration tower group Operation management can be easily performed, and cleaning according to the purpose can be accurately performed.

This is because not only the operation mode 2 but also the ion-exchange resin which is not pre-coated on the A-filtration group 12 is used. The same can be said for the operation mode 3 in which water is passed through the B filtration group. In addition, since the cleaning state of the filtration element can be grasped from the detection values of the differential pressure detectors 16 and 17, as in operation modes 1 and 4, A
Even when only one of the filtration tower group 12 and the B filtration tower group 14 is operating, the cleaning time can be known.

Further, the valve opening regulator 18 can be set so as to selectively operate the A filtration tower group 12 and the B filtration tower group 14 according to the operation mode of the plant.
The use of the filtration tower group 12 and the B filtration tower group 14 can be automatically performed.

[0048]

As described above, according to the first and second aspects of the present invention,
According to 2, the condensate filtration device comprises a first filtration tower having a pleated filtration element and a second filtration tower having a hollow fiber membrane type element connected in parallel with each other, and the first filtration tower and the second filtration tower By using the two filtration towers separately, the condensate condensed in the condenser can be washed as desired, so that insoluble impurities can be removed and the solubility can be reduced. Impurities can also be removed, and condensate before starting the plant can be efficiently washed.As a result, the life of the condensate desalination unit can be reliably extended, and the operating cost can be reduced accordingly. effective.

According to the third aspect of the present invention, the apparatus has the differential pressure detecting means and the control means so as to keep the flow rates of the first filtration tower and the second filtration tower uniform. In addition to the effects of the first and second aspects, it is possible to provide an apparatus that can easily perform the operation management of the first and second super towers and can appropriately perform cleaning according to the purpose.

According to the fourth and fifth aspects, the condensate removal function can be arbitrarily changed according to the condensate state before the plant is started or during operation. There is an effect that desired washing can be performed on the condensed water, and in particular, according to claim 5, since the flow rate flowing through the first filtration tower and the second filtration tower is configured to be kept uniform,
Operation management of the first and second filtration towers can be easily performed,
There is an effect that cleaning according to the purpose can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a schematic piping diagram showing an embodiment in which a nuclear power plant according to the present invention is applied to a boiling water nuclear power plant.

FIG. 2 is a piping diagram showing a condensate filtration device.

FIG. 3 is an explanatory view of an operation mode showing one embodiment of an operation method of a power plant when the apparatus of the present invention is used.

FIG. 4 is a piping diagram for explaining the relationship between a valve opening regulator and a flow control valve, showing details of a condensate filtration device.

FIG. 5 is an explanatory sectional view showing a general powder resin precoat type condensate filtration device.

FIG. 6 is an explanatory sectional view showing a general hollow fiber membrane filter type condensate filtration device.

FIG. 7 is an explanatory perspective view showing a pleated element.

FIG. 8 is an explanatory diagram showing the relationship between the differential pressure in the upstream and downstream portions of various filtration towers and the operation time.

FIG. 9 is a piping diagram showing a conventional nuclear power plant.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Water supply system, 2 ... Nuclear reactor, 4 ... Steam turbine, 5 ... Condenser, 6 ... Condensate filtration apparatus, 12 ... A filtration tower, 14 ... B tower filtration tower, 13, 15 ... Flow control valve, 16 , 17: Differential pressure detector, 18: Valved E controller, 7: Condensate desalination device.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshihiro Shiozawa 3-2-1 Sachimachi, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Co., Ltd.

Claims (5)

[Claims] In a nuclear power plant having a condensate system in which a condensate filtration device and a condensate desalination device are connected in series to a condensate pipe, the condensate filter is connected in parallel to the condensate pipe. A nuclear power plant, characterized in that at least the filtration element comprises a first condensate filtration tower having a pleated filtration element and a second condensate filtration tower having a hollow fiber membrane type filtration element. 2. In a nuclear power plant having a condensate system in which a condensate filtration device and a condensate desalination device are connected in series to a condensate pipe, the condensate filter is connected in parallel to the condensate pipe. The first condensate filtration tower having at least a filtration element having a pleated filtration element and a second condensate filtration tower having a filtration element having a hollow fiber membrane type, wherein the condensate filtration tower, filtration A nuclear power plant, wherein an ion exchange resin having a pre-coated element and an ion exchange resin not having a pre-coated filter element are selectively mounted. 3. A nuclear power plant having a condensate system in which a condensate filtration device and a condensate desalination device are connected in series to a condensate pipe, wherein the condensate filtration device has a pleated filter element. A first condensate filtration tower having, and a second condensate filtration tower connected in parallel with the first condensate filtration tower, and having a filtration element of a hollow fiber membrane type,
A differential pressure detector for detecting a differential pressure between an upstream portion and a downstream portion of each of the first and second condensate filtration towers; and a first and a second condensate filter based on a detection signal of the differential pressure detector. A nuclear power plant having control means for adjusting a flow rate of condensate to the water filtration tower. 4. A method for operating a nuclear power plant having a condensate system in which a condensate filtration device and a condensate desalination device are connected in series to a condensate pipe, wherein the filter element and the ion exchange resin are precoated with an ion exchange resin. A first condensate filtration tower consisting of a pleated type to which a filtration element not pre-coated is selectively mounted,
Using a condensate filtration device in which a second condensate filtration tower having a hollow fiber membrane type filter element and a condensate pipe are connected in parallel to the condensate pipe, the first condensate is equipped with a filter element pre-coated with ion exchange resin. While the water is passed through the condensate filtration tower, the first step in which the condensate is not passed through the second condensate filtration tower, and the water is passed through the first condensate filtration tower equipped with a filtration element pre-coated with ion exchange resin Along with the second step of passing water through the second condensate filtration tower, and passing water through the first condensate filtration tower equipped with a filtration element that does not precoat the ion exchange resin, Selectively execute the third step of passing water and the fourth step of not passing water to the first condensate filtration tower while passing water only to the second filtration tower according to the state before plant startup and during plant operation. Nuclear power plant characterized by Driving method. 5. A method for operating a nuclear power plant having a condensate system in which a condensate filtration device and a condensate desalination device are connected in series to a condensate pipe, wherein the filter element and the ion exchange resin are precoated with an ion exchange resin. A first condensate filtration tower consisting of a pleated type, on which a filtration element not pre-coated is selectively mounted,
A second condensate filtration tower having a hollow fiber membrane type filtration element and a condensate filtration device connected in parallel to a condensate pipe in advance, and a second condensate filtration element pre-coated with an ion exchange resin is mounted. While the water is passed through the first condensate filtration tower, the first step in which condensate is not passed through the second condensate filtration tower, and the first condensate filtration tower equipped with a filtration element pre-coated with ion exchange resin. Along with water, the second step of passing water through the second condensate filtration tower, and passing water through the first condensate filtration tower equipped with a filtration element that does not precoat the ion exchange resin, and the second condensate filtration tower The third step of passing water through the first condensing filtration tower and the fourth step of passing water only through the second filtration tower while not passing through the first condensing filtration tower are selectively performed according to the state before the plant is started and during the operation of the plant. And the second and third steps are performed Based on the magnitude of the pressure difference between the upstream part and the downstream part of the first and second condensing filtration towers, the flow rate of the first condensing filtration tower and the flow rate of the second condensing filtration tower are approximately A method for operating a nuclear power plant characterized by equalizing.