JPS60201290A - Cooling facility on stoppage of nuclear reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to cooling equipment during reactor shutdown in a nuclear power plant, and in particular, cooling equipment during reactor shutdown that shortens warm-up time and reduces the risk of radiation exposure. Regarding equipment.

[Technical Background of the Invention 1] In boiling water type nuclear power plants and the like, a reactor shutdown cooling facility is installed in order to quickly cool down the nuclear reactor when the reactor is shut down.

This reactor shutdown cooling equipment often shares components with low-pressure water injection equipment and containment vessel cooling equipment, which are part of the emergency core cooling system.

FIG. 1 shows the schematic configuration of these facilities. The piping 3 connecting the reactor pressure vessel 1 and the heat exchanger 2 is equipped with an isolation valve 4.
A pump 5 is inserted, and a bypass valve 7 is inserted in a pipe 6 that bypasses the heat exchanger 2.

From the outlet side piping 8 of the heat exchanger 2, a cooling piping 10 for reactor shutdown equipped with an isolation valve 9, a low-pressure water injection piping 12 equipped with an isolation valve 11, and an isolation valve 13 and a water injection nozzle 14 are provided. Containment vessel cooling piping 15 is branched and connected. Moreover, between the pressure suppression chamber 16 and the pipes 8 and 3, pipes 19.20 each having a regulating valve 17.18 are connected.

The dashed-dotted line frame in FIG. 1 indicates the low-pressure water injection equipment 21,
The two-dot chain line frame indicates the containment vessel cooling equipment 22, and the dotted line frame indicates the reactor shutdown cooling equipment 23.

Therefore, the pump 5 and the bypass valve 7 are common equipment C of the low pressure water injection equipment 21 and the reactor shutdown cooling equipment 23, and the heat exchanger 2
are the containment vessel cooling equipment 22 and the reactor shutdown cooling equipment 23.
The regulating valve 18 is a shared equipment for the low pressure water injection equipment 2.
1 and the containment vessel cooling equipment 22.

In the reactor shutdown cooling equipment 23 configured using such shared equipment, C prioritizes the use of the low-pressure water injection equipment 21 and the containment vessel cooling equipment 22 in the event of an accident during plant operation. Usable operating conditions are restricted.

On the other hand, the isolation valve 4 that constitutes the reactor shutdown cooling equipment 23,
The normal temperature of the pump 5, piping 3.8, etc. is room temperature a.
There is a large temperature difference between the temperature and the high temperature primary cooling water in the reactor pressure vessel 1.

Therefore, when the reactor shutdown cooling equipment 23 starts operating, high-temperature water is introduced into the cold section and cold/warm water is introduced into the high-temperature section. It is essential to warm up the system equipment.

This warm-up is performed by discharging high-temperature primary cooling water from the reactor pressure vessel 1 to the pressure suppression chamber 16 through the regulating valve 17 provided on the outlet side of the heat exchanger 2.
After completion of this, the operation of the reactor shutdown cooling equipment 23 is started.

[Problems with the Background Art] However, in the conventional reactor shutdown cooling equipment configured as described above, the priority is low during plant operation, and after the plant is shut down, the low pressure water injection equipment 21 and the containment Since warm-up can be started by switching the valve from the container cooling equipment 22, there is a drawback that it takes a long time until the start of operation.

In addition, since the facility water discharge path is restricted by the capacity of pipe 19, it is difficult to warm up the equipment through pipes 3. This is one reason why it takes a long time to warm up. Furthermore, since the waste water from the equipment is primary cooling water containing high radioactivity from the reactor pressure vessel 1, there is a problem in that the radiation dose in the pressure chamber 16 flowing into the reactor chamber 16 increases.

[Object of the invention] An object of the present invention is to provide cooling equipment during reactor shutdown that can shorten the IJI time and reduce the amount of primary cooling water discharged to the pressure suppression chamber. .

[Summary of the invention] In the present invention, isolation valves are provided at the entrances and exits to the reactor pressure vessel, respectively, and pumps and heat exchangers are sequentially inserted into the reactor pressure vessel from the upstream side. In the reactor shutdown cooling equipment, which has a reactor water circulation pipe and a reactor water JJI output pipe from the downstream side of the heat exchanger to the pressure suppression chamber via a regulating valve, the reactor water circulation pipe is A connecting pipe connecting the downstream side of the outlet side isolation valve and the upstream side of the inlet side isolation valve, and a regulating valve inserted in the connecting pipe;
A check valve provided on the discharge side of the pump, a bypass valve provided in parallel to the check valve, a pipe that bypasses the pump and check valve connected in series, and an intervention inserted into the pipe. The above objective is achieved by providing a cooling facility for nuclear reactor shutdown having a second pump.

[Embodiments of the invention] Hereinafter, embodiments of the present invention will be described with reference to FIG.

In FIG. 2, parts common to those in FIG. 1 are denoted by the same reference numerals.

In FIG. 2, the primary cooling water from the reactor pressure vessel 1 passes through the pipe 3, is pressurized by the pump 5, flows into the heat exchanger 2 from the pipe 3a, and after removing heat there, the water is removed from the pipe 8.1.
0, returns to the C reactor pressure vessel 1 via the isolation valve 9.

The piping 3 and the piping 10 are provided with an isolation valve 4.9 that isolates the reactor pressure vessel 1 from the reactor shutdown cooling equipment 23. When the reactor shutdown cooling equipment 23 is not used, the isolation valve 4.9 is installed. is closed.

A communication pipe 30 is connected between the downstream side of the isolation valve 4 and the upstream side of the isolation valve 9, and the communication pipe 30 is provided with a flow rate adjustment valve 31.

The discharge side piping 3a of the pump 5 has a reverse Il connected to the outlet of the pump 5.
- A valve 32 and a bypass valve 33 that bypasses this valve are inserted. Further, a small capacity warm-up pump 34 is connected between the pipes 3 and 3a so as to bypass the pump 5 and the check valve 32.

In the nuclear reactor shutdown cooling equipment of the present invention configured as described above, -C is a system in which the isolation valve 4.9 is closed and the cooling film S2 is cooled by the pump 5 or the warm-up pump 34.
It is possible to circulate the system water within 3. In this case, if the isolation valve 4.9, regulating valve 17, and regulating valve 31 are opened to appropriate opening degrees and the pump 5 or the warm-up pump 34 is driven, the circulation system in the cooling equipment 23 during reactor shutdown is High temperature water from the reactor pressure vessel 1 can be mixed in in appropriate amounts.

Therefore, when the nuclear coupler is shut down, the first flow rate regulating valve 31 is opened to a predetermined opening degree, the pump 5 is operated with the secondary cooling water of the heat exchanger 2 stopped, and the cooling equipment 2 is operated when the reactor is shut down.
After circulating the water in 3, isolation valve 4.9 and regulating valve 17
l! fl 6, if part of the water in the reactor shutdown cooling equipment 23 is drained into the pressure suppression chamber 16 through this regulating valve 17, the reactor can be shut down by taking in the high temperature primary cooling water in the reactor pressure vessel 1. The cooling equipment 23 can be quickly warmed up.

In addition, by listening to the isolation valve 4.9, closing the flow rate adjustment valve 31, and operating the warm-up pump 34, the high-temperature secondary cooling water of the reactor pressure vessel 1 is circulated little by little in the piping 3.10. This makes it possible to prevent sudden humidity changes that occur when the pump 5 is operated.

Even in this case, by adjusting the same h of the flow rate regulating valve 31, the amount of water taken in from inside the reactor pressure vessel 1 can be adjusted, and the speed of warm-up can be changed. Further, the pump 5 can be warmed up by closing the bypass valve 33 and circulating the system water in reverse.

[Effects of the Invention] As explained above, the reactor shutdown theory No. 41 equipment of the present invention is equipped with a circulation flow rate adjustment valve in the connecting pipe that connects the entrance and exit of the equipment, and also supplies IJI water to the pressure suppression chamber as necessary. Since it is equipped with a regulating valve to warm up 11. 1. In addition, primary cooling to the pressure suppression chamber 1. II water +
jl water 1 is greatly reduced, and the discharge capacity of the pressure suppression chamber can be reduced.

In addition, when using a small-capacity warm-up pump, a bypass valve is installed in the outlet check valve of the large-capacity pump.
It is possible to warm up the large-capacity pump, and it is possible to alleviate heat stress when the cooling equipment is activated when the Toi sub-reactor is shut down.

[Brief explanation of drawings]

Figure 1 [Schematic diagram of conventional cooling equipment during reactor shutdown, Figure 2]
The figure is a schematic diagram showing one embodiment of the invention. 1......Reactor pressure vessel 2...
......Heat exchanger 4.9.11.13...Isolation valve 5...Pump 7... Bypass valve 14...
・・・・・・Water injection nozzle 16・・・・・・・・・・・・
・Pressure suppression chamber 17.18...Adjusting valve 21...Low pressure water injection equipment 22...
......Containment vessel cooling equipment 23...
・・・・・・Reactor shutdown cooling equipment 30・・・・・・
・・・・・・Connection pipe 31・・・・・・・・・Flow rate adjustment valve 32・・・・・・・・・Check valve 33・・・・・・・・・・・・...Bypass valve 34...
・・・・・・・・・Warming pump agent Patent attorney Suyama
- Figure 1 Figure 2

Claims (1)

[Claims] (1) Isolation valves are provided at each entrance and exit to the reactor pressure vessel, and piping for circulating reactor water in the reactor pressure vessel, in which a pump and a heat exchanger are sequentially inserted from the upstream side, and the heat exchanger In a reactor shutdown cooling facility that has a reactor water discharge piping that reaches the pressure suppression chamber from the downstream side of the reactor via a regulating valve, A connecting pipe connecting the upstream side of the inlet side isolation valve, an I adjustment valve inserted in the connecting pipe, a check valve provided on the discharge side of the pump, and a check valve installed in parallel with the check valve. 1 for cooling at the time of shutdown of the Ushi reactor, characterized in that it has a bypass valve, a piping that bypasses the pump and the check valve connected in series, and a second pump inserted into the piping.
Facility.