JP2563506B2 - Reactor coolant purification equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a reactor coolant cleaning facility used in a boiling water nuclear power plant.

(Prior Art) Conventionally, a boiling water nuclear power plant is provided with a reactor coolant purification facility. This reactor coolant purification facility is configured to take out a part of the coolant flowing in the reactor output vessel, filter and desalt the salt, and then return it to the reactor pressure vessel again. Furthermore, the excess coolant generated by thermal expansion of the coolant at startup of the reactor and the excess coolant produced by the cooling water of the control rod drive mechanism flowing into the reactor pressure vessel are drained from the reactor pressure vessel. It is like this.

FIG. 2 is a system diagram showing a conventional example of a reactor coolant purification facility. A part of the coolant in the reactor pressure vessel 1 is extracted through a reactor coolant purification system pipe 30 branched from a recirculation pipe 2 connected to the lower part of the reactor pressure vessel 1, and a regenerative heat exchanger 3, After being cooled by the non-regeneration heat exchanger 4, pressurized by the reactor coolant purification system pump 5 and purified by the filter desalting device 6, heat is recovered by the regeneration heat exchanger 3 and the water supply pipe 7 is connected. After that, it returns to the reactor pressure vessel 1 again. The branch pipe 29 branched from the outlet side pipe 8 of the filter desalination apparatus 6 was provided with a pipe 11 provided with a gate valve 10 connecting to the turbine main condenser 9 and a gate valve 13 connecting to the liquid waste treatment system 12. It is connected to the pipe 14. The surplus coolant is discharged to the turbine main condenser 9 or the liquid waste treatment system 12 by closing the sluice valve 15 and opening the sluice valve 10 or the sluice valve 13. And
This wastewater is treated by the liquid waste treatment system 12, and is guided to the condensate storage tank 23 via the pipe 24. Therefore, by setting the discharge destination of the excess coolant to two, even if one cannot be used due to maintenance / inspection, etc., it can be switched to the usable one so that the drainage of the excess coolant is not hindered. ing.

Further, at the nuclear power plant, periodic inspection and fuel exchange are performed about once a year, and at that time, pool water is introduced into the reactor well pool and the temporary equipment pool.
After exchanging the fuel, the pool water of the reactor well pool and the temporary equipment pool is drained to the condensate storage tank by the fuel pool cooling and purification facility.

When the pool water is drained, the reactor pressure vessel 1 is opened as shown in FIG. 3, so that the pool water of the reactor well pool 16 and the temporary equipment pool 17 and the cooling of the reactor pressure vessel 1 are substantially provided. The material is one. Therefore, the sluice valves 13 and 15 are closed and operated in the same manner as the surplus coolant drainage method.
Opening 0 opens the pool water to the turbine main condenser 9. Therefore, it is possible to shorten the drainage time as compared with the case where the pool water drainage operation is performed only with the fuel pool cooling / purification facility (not shown).

Similarly, it is possible to discharge the pool water to the liquid waste treatment system 12 by closing the sluice valves 10 and 15 and opening the sluice valve 13, but the treatment capacity in the liquid waste treatment system 12 is small. Therefore, it is not possible to continue draining at the rated flow rate of the reactor coolant purification system pump 5, so that the contribution to shortening the pool water drainage time becomes small.

(Problems to be Solved by the Invention) In such a conventional method for operating a fuel pool cooling / purifying facility, it is possible to reduce the radioactivity level of the stored water discharged from the reactor well pool and the equipment temporary pool to the condensate storage tank. There was a problem that it was not always enough.

An object of the present invention is to improve the safety of a nuclear power plant by reducing the radioactivity level of discharge water to a condensate storage tank and a main condenser, and to shorten pool water drainage time. Accordingly, it is an object of the present invention to provide a reactor coolant purifying apparatus aiming at shortening the periodic inspection time and improving the operation efficiency.

[Structure of Invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a regenerative heat exchanger is branched from a recirculation pipe connected to a reactor pressure vessel, and a non-regenerated heat exchanger, In a reactor coolant purification facility having a reactor coolant purification pump and a pipe that has a filter desalination unit and joins a water supply pipe, the reactor coolant branching unit is branched from the downstream side of the filter desalination unit and connected to a suppression pool. Branch pipe, a stop valve provided on the branch pipe, a first pipe connecting the suppression pool and the waste treatment system via a pump, the waste treatment system and a condensate storage tank. And a second pipe for connecting to the reactor.

(Operation) In the reactor coolant purification system configured as described above, the drained pool water is purified by the filter desalting device and drained to the suppression pool. Therefore, since the discharge water is discharged into the suppression pool, the pool water can be discharged at the rated flow rate of the reactor coolant purification system pump regardless of the treatment capacity of the waste treatment system, and the pool water drainage time can be shortened. You can

(Example) Hereinafter, a reactor coolant purification facility according to an example of the present invention will be described with reference to FIG.

In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description of the structure of those parts will be omitted.

As shown in FIG. 1, at the time of periodic inspection, the reactor well pool 16 and the temporary equipment pool 17 are filled with the same coolant and are substantially integrated with the reactor pressure vessel 1. The reactor pressure vessel 1 is connected to the reactor coolant purification equipment 28 via the recirculation pipe 2, and the regenerative heat exchanger is connected from the upstream side.
3, a non-regenerated heat exchanger 4, a reactor coolant purification system pump 5, and a filter desalination device 6 are sequentially provided. A branch pipe 29 branched from the outlet side pipe 8 of the filter desalination apparatus 6 is provided with a sluice valve 19 for communicating with the suppression pool 18 and a sluice valve 13 for communicating with the liquid waste treatment system 12. Connected to 14. The suppression pool 18 is a liquid waste treatment system through a pipe 22 equipped with a residual heat removal system pump 21.
A pipe 24 is provided that is connected to the liquid waste treatment system 12 and is connected to the condensate storage tank 23.

Next, the reactor coolant purification facility 28 configured in this way
A method of draining pool water from the reactor well pool 16 and the temporary equipment pool 17 to the condensate storage tank 23 will be described.

As shown in FIG. 1, the pool water a of the reactor well pool 16 and the temporary equipment pool 17 is substantially integrated with the coolant b in the reactor pressure vessel 1, so that the reactor coolant purification system pump 5 The water can be taken into the reactor coolant purification facility 28 by operating the. The pool water taken in is cooled by the regenerative heat exchanger 3 and the non-regenerated heat exchanger 4, passed through the reactor coolant purification system pump 5, and then purified by the filter desalting device 6. The purified pool water is discharged to the suppression pool 18 via the pipe 20 by closing the sluice valves 15 and 13 and opening the sluice valve 19.

Next, the pool water drained to the suppression pool 18 is operated by the residual heat removal system pump 21 to operate the piping 22.
Is sent to the liquid waste treatment system 12 via. Then, after being purified by the liquid waste treatment system 12, it is drained to the condensate storage tank 23 via the pipe 24.

By temporarily storing the pool water discharged as described above in the suppression pool 18, the waste treatment system 12
The pool water can be discharged at the rated flow rate of the reactor coolant purification system pump 5 regardless of the processing capacity of the above. The pool water temporarily stored in the suppression pool 18 is gradually sent to the liquid waste treatment system 12 to be treated and stored in the condensate storage tank 23.

In addition, the drainage of excess coolant that occurs when the reactor starts up,
Normally, the liquid waste treatment system 12 is drained through the pipe 14, and when the liquid waste treatment system 12 cannot be used, it is drained to the suppression pool through the pipe 20 to provide the same operability as the conventional drainage method. Can have.

〔The invention's effect〕

As described above, according to the present invention, the pool water of the reactor well pool and the equipment temporary storage pool is double purified through the filter desalting device and the liquid waste treatment system, respectively, and then drained to the condensate storage tank. Therefore, the radioactivity level of the stored water in the condensate storage tank can be further reduced, and the safety of the nuclear power plant can be improved.

Further, the pool water drainage time can be further shortened by performing the pool water drainage operation of the reactor well pool and the equipment temporary storage pool according to the present invention at the same time as the drainage operation by the fuel pool cooling and purification facility, and The plant operating efficiency can be improved by shortening.

Further, in the embodiment of the present invention, instead of newly installing a pipe connecting the outlet side pipe of the filtration and desalination apparatus to the suppression pool, the pipe connecting the outlet side pipe to the turbine main condenser in the related art is deleted. As a result, it is possible to reduce the amount of piping, and it is possible to reduce the radioactivity level of the turbine equipment by not draining the excess coolant generated at the time of conventional reactor startup to the turbine main condenser.

[Brief description of drawings]

FIG. 1 is a system diagram showing a reactor coolant purification apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are system diagrams showing conventional reactor coolant purification apparatuses. 1 …… Reactor pressure vessel 2 …… Recirculation piping 3 …… Regeneration heat exchanger 4 …… Non-regeneration heat exchanger 5 …… Reactor coolant purification system pump 6 …… Filtration desalination device 12 …… Liquid disposal Waste treatment system 16 …… Reactor well pool 17 …… Temporary equipment pool 18 …… Suppression pool 21 …… Residual heat removal system pump 23 …… Condensate storage tank 28 …… Reactor coolant purification facility 29 …… Branch Piping 30 …… Piping for reactor coolant purification system

Claims (1)

(57) [Claims] 1. A recirculation pipe connected to a reactor pressure vessel, having a regenerative heat exchanger, a non-regenerative heat exchanger, a reactor coolant purification pump, and a filter desalting device. In a reactor coolant purification facility having a pipe that joins a water supply pipe, a branch pipe branched from the downstream side of the filtration desalination device and connected to a suppression pool, and a stop valve provided on this branch pipe, A reactor comprising: a first pipe connecting the suppression pool and a waste treatment system via a pump; and a second pipe connecting the waste treatment system and a condensate storage tank. Coolant purification equipment.