JPS59184890A - Reactor cooling system facility - 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] [Field of Application of the Invention] The present invention relates to nuclear reactor cooling system equipment, particularly a recirculation system (hereinafter referred to as PLR), a residual heat removal system (hereinafter referred to as RI-i), The present invention relates to a reactor cooling system facility having a coolant purification system (hereinafter referred to as CUW), a water supply system (hereinafter referred to as FDW), and an isolation cooling system (hereinafter referred to as RCIC).

[Prior art]

Figure 1 shows the system of conventional reactor cooling system equipment, where 1 is the reactor pressure vessel, 2 is the PLR, 3 is the RHR, 4
and 5 are the stop cooling system (hereinafter referred to as SHC) and the low pressure water injection system (hereinafter referred to as L
6 is CUW.

7 is FDW and 8 is RC C.

P L R2 is the reactor pressure vessel 1. P L R for forced circulation of coolant inside the reactor pressure vessel 1, pump 9゜PL
It is composed of R pump inflow line 10P L R pump out line 11.

RHR3 branches into 10 Roshiro lines with PLR pumps,
The coolant in the reactor pressure vessel 1 that has passed through the primary side of the pump 12 and the heat exchanger 13 and is cooled is transferred to the heat exchanger outlet line 14.
5I (C passes through the PLR-8HC piping piping section 15 and connects to the PLR pump output Roshiro line 11), and the coolant that has passed through the primary side of the heat exchanger 13 is transferred to the heat exchanger outlet line. The device CU W 6 is composed of an LPCI 5 that returns directly from the LPCI 5 to the reactor pressure vessel 1 via a valve 17 , branches into a PLR pump-equipped Rosiro line 10 , and connects the primary side of the CUXV pump 18 and the CUW regenerative heat exchanger 19 . The coolant inside the reactor pressure vessel purified by the filter desalination device 20 is passed through the CUW return line 21 and the valve 22 to the W/CUW piping joint 2.
3 to the ]="DW line 24 of the FDW 7.

RCIC 8 includes RCIC pump 25 and discharge line 26
The structure is such that it is connected to the reactor pressure vessel via the reactor pressure vessel.

In the conventional reactor cooling system equipment having such a configuration, in the 5HC4, during normal operation, the internal fluid temperature of the PLR pump output Rosillo line 11S' I-I C return line 15 is approximately 177C and 72C, respectively, and both The temperature difference between the two is about 105C. Therefore, two fluids with this temperature difference continuously P L R - S during normal operation.
I (at C piping joint 16).

Because of this, there was a high risk of damage to the piping due to thermal fatigue.

In the COW 6, the PLR pump is branched from the 1-person line 10 and is purified by the CUW regeneration heat exchanger 1E01 through the CUW pump 18. FDW via CUA ■ piping joint 23
Reactor cooling entering line 24. During reactor startup, shutdown, and high-temperature standby, the internal fluid temperatures of the COW return line 21 and FDW line 24 are below 40C and 22C, respectively.
It becomes 0C or less, and the temperature difference between the two becomes 1soC or more.

Therefore, during the life of the plant, there was a high risk that the piping would be damaged due to thermal fatigue due to the temperature difference at the FDW-CUW piping joint 23.

[Purpose of the invention]

The present invention provides PLR, -8l (C piping joint and FDW-
The object of the present invention is to provide a reactor cooling system equipment that can prevent damage caused by thermal fatigue at CUW piping joints.

[Structure of the invention]

The present invention provides a nuclear reactor cooling system equipment having a recirculation system, a residual heat removal system, a coolant purification system, a water supply system, and an isolation cooling system, in which the return line for residual heat removal and at the time of reactor startup,
A flow path is provided through which the return line of the coolant purification system during shutdown and high temperature periods communicates with the reactor via at least one of the low pressure water injection system of the residual heat removal system and the isolation cooling system. It is characterized by:

That is, the SHC return water is converted to L which is a part of R H R,
It is returned to the reactor via PCI or RCIC to prevent the two fluids from mixing, and when there is a 2M degree difference between FDW and COW, for example at reactor startup, the CU"vV return water is
- PLR.・Significantly reduces the potential for piping damage due to thermal fatigue at SHC joints and PDW-CUW joints, resulting in high reliability, and the removal of SII C return piping reduces the volume of reactor containment vessel penetrations and piping. The aim is to provide nuclear reactor cooling system equipment that is rational and capable of reducing radiation exposure for employees.

[Embodiments of the invention]

2 to 7 show systems of different embodiments of the present invention, and the same parts as in FIG. 1 are given the same reference numerals.

In the embodiment shown in FIG. 2, a remote control valve 27 and a check valve 28 are provided between the COW return line 21, which is the outlet of the CUW filter desalination device 20, and the heat exchanger outlet line 14 of R, HR3. A tie line consisting of piping 29 is provided.

In this embodiment, during reactor startup, shutdown, high temperature standby, etc., the valve 22 provided in the CU'W return cylinder 21 is closed, and the remote control valve 27 and the valve 17 of the LPCI 5 are opened. , COW return water is not returned to FDW7, LP
Return to reactor pressure vessel 1 via CI5. By doing so, mixing of two fluids with a large temperature difference at the FDW-CUW piping junction 23 can be avoided.

Table 1 shows approximate values of the temperature of the two systems and the flow rate of FDW during reactor startup, shutdown, and high-temperature standby.As is clear from the above explanation and Table 1, The temperature difference between FDW and CUW during high temperature standby is approximately 185
Although this also applies to C, in this embodiment, the temperature difference in the vicinity of the joint between the reactor pressure vessel 1 and the LPCI 5 line during startup, shutdown, and high-temperature standby is sufficiently small, so that the problem of thermal fatigue damage does not occur.

In addition, during normal operation, the CUW return water is supplied to the remote control valve 27.
With the valve 17 of the LP CI 5 closed, the valve 22 is opened and the FDW is returned to the FDW line 24.
The temperature difference between CUW 7 and CUW 6 is about 400, which is sufficiently small to cause no problem.

In the actual case shown in FIG. 3, the CUW return line 21 which is the outlet of the CUW filter/desalination device 20
RCI between the discharge line 26 of the RCIC pump 25 and
C pump remote control valve 30. A tie line consisting of a pipe 32 in which a check valve 31 is provided is provided.

In this embodiment, during reactor startup, shutdown, high temperature standby, etc., the valve 22 provided in the CUW return line 21 is closed, and the remote control valve 30. CUW
The return water is not returned to the FDW 7 but is returned to the reactor pressure vessel 1 via R and ClC 8. By doing so, it is possible to obtain the same effect as the embodiment shown in FIG.

In the embodiment shown in FIG. 4, a tie consisting of piping 35 is provided with a remote control valve 33 and a check valve 34 between the heat exchanger outlet line 14 of the RHR 3 and the discharge line 26 of the RCIC pump 25 of the RCIC 8. a line is provided, and
Branched from the heat exchanger outlet line 14 of R, HR3 and connected to R, C
S in the conventional case shown in FIG. 1 leading to the R pump outlet line 11
HC return line 15 has been removed. In other words, this tie line has R and CI when the R and CIC pumps are in operation.
A check valve 34 is installed to prevent the C supply water from flowing backward, and the LPIC
5 Remote control valve 3 to enable system isolation when activated
3 are provided on the downstream side and upstream side of the tie line, respectively.

In this example, since the 5HC4 of R and HR3 is used when the reactor is shut down, the internal fluid is not returned to the operating PLR2 when the reactor is started, but is passed through the RCIC8 which is not operating when the reactor is started. It is returned to the furnace pressure vessel 1.

Therefore, PLR as a high temperature fluid that causes thermal fatigue,
It becomes possible to avoid repetition of the merging phenomenon of the side internal fluid and the 8l-(C side internal fluid as a low-temperature fluid).

Since the unnecessary SMC return line is no longer required, it is possible to reduce the need for SHC piping and piping support 1- in the reactor containment vessel (hereinafter referred to as PCV) 36 and SHC piping in the PCV 36.
, valves, insulation materials, instruments, etc. can be removed, making it possible to significantly reduce costs. P
Radiation of S 1-I C piping occurs during regular inspections, pipe service inspections, valve disassembly inspections, PT and R pump disassembly inspections, heat insulation repairs, air conditioner inspections, valve operation tests, etc. carried out in CV36. It is possible to eliminate exposure to radiation caused by the function, improve the efficiency of regular inspection work, and shorten work time. Also, S
Since the HC return water is returned from the top of the reactor pressure vessel 1 via the RCIC 8, the convection of the primary cooling water in the reactor pressure vessel 1 can be carried out efficiently, and the heat recovery of the primary cooling water in the reactor pressure vessel can be carried out efficiently. This is effective for shortening the SHC operating time.

In the embodiment of FIG. 5, heat exchanger outlet line 1 of RHR3
The SHC return line 15 in the prior art case of FIG.

In this embodiment, the LPCI 5 is used to open the valve 17 to return SMC return water to the reactor pressure vessel 1. In this case as well, thermal fatigue points can be reduced, and streamlining can be achieved by eliminating piping for the SHC return line.

The embodiment of FIG. 6 has a tie line having a configuration similar to that of the embodiment of FIG. A tie line consisting of a pipe 35 provided with a check valve 34, and a pipe 38 provided with a valve 37 between the upstream side of the check valve 34 of this tie line and the outlet side of the filter desalination device 20. More tie lines are connected.

In this embodiment, during reactor startup, shutdown, and high-temperature standby, the CUW return water is transferred to the FD by closing the valve 22 of the CUW return line 21, closing the valve 33, and opening the valve 37.
Instead of returning to W7, it is returned to the reactor pressure vessel 1 via the discharge line 26 of the RCIC8.

Further, when the reactor is shut down, the valve 33 is opened and the valve 37 is closed, and the secondary cooling water is returned to the reactor pressure vessel 1 via the RCI C8 which returns the water to PLI%2.

As a result, the same effects as the embodiments of FIGS. 3 and 5 can be obtained, and furthermore, the rationalization of system equipment can be done by organic system configuration.

In the embodiment of FIG. 7, a valve 39. A tie line consisting of a valve 40 and piping 41;

Valve 4 between valve 39 and valve 40 of the engine and RCIC 8.
2. A tie line consisting of a pipe 44 having a check valve 43 and a check valve 43 is connected thereto.

In this example, during reactor startup, shutdown, and high temperature standby, C
By closing the valve 22 of the UW return line 21, closing the valve 39, and opening the valves 40 and 42, the CUW return water is
Instead of returning to DW7, it is returned to reactor pressure vessel 1 via discharge lines 26 of R, C1, and C8. Also, by closing the valves 22 and 42, opening the valves 39 and 40, and opening the valve 17, the reactor pressure vessel 1
The primary cooling water can be returned to the Furthermore, after the nuclear reactor is shut down, by closing valve 42 and opening valves 39 and 40, it becomes possible to return SHC return water to F'DW 7. At this point, FDW7 is stopped,
There is no fear of thermal fatigue damage at the FDW-CUW piping joint 23. Alternatively, close valve 17, close valve 40, close valve 39,
By opening the valve 42, the SHC return water is
It is possible to return the fuel to the reactor pressure vessel 1 via the CIC line 26.

As mentioned above, FDW7 and CUW6 and PLR2 and 5HC
4 can be avoided, and the same effects as the embodiments shown in FIGS. 3 and 5 can be obtained.

As mentioned above, in the reactor cooling system equipment of the example,
Piping joint between FDW and CUW, P J, R and S H
A highly reliable atomic couplant can be obtained by eliminating the cause of thermal fatigue loss at the piping joint with C and both. Furthermore, since the SHC piping can be removed from the reactor containment vessel, the amount of piping penetrations, valves, piping, heat insulating materials, piping sabots, etc. can be significantly reduced, making it possible to construct a rational plant. By removing the SHC piping, which is radioactive piping, it is possible to reduce the radiation exposure of workers.

〔Effect of the invention〕

The present invention makes it possible to provide nuclear reactor cooling system equipment that can prevent damage caused by thermal fatigue at PLl, (, S I-I C piping joints and FDW-CUW piping joints, and is useful for industrial purposes. It's a big effect.

be.

[Brief explanation of drawings]

Figure 1 is a system diagram of conventional reactor cooling system equipment, Figure 2~
FIG. 7 is a system diagram of different embodiments of the reactor cooling system equipment of the present invention. 1...Reactor pressure vessel, 2...PLR, 3...R
HR14...SHC, 5...LPCI, 6...C
UW, 7...FDW, 8...RCIC, 10...
PL, R, pump inlet line, 11...PLR pump output line 3...heat exchanger, 14...heat exchanger outlet line, 15...SCR return line, 16...
PLR・S HC piping joint, 17...Valve, 20...
Filter desalination equipment, 2l-CUW return line, 22-
Valve, 23-CTJW/I"DW piping joint, 26...
Discharge line, 27°30.33...Remote control valve, 28
, 31.34... Check valve, 29, 32. 35... Piping, 36... p c v, 37 Remote control valve, 38.
・・Piping, 39, 4.0° 42・Remote control valve, 43・・
Check valve, 41.44...Piping.

Claims (1)

[Claims] 1. Recirculation system, residual heat removal system, coolant purification system, water supply system,
And in the reactor cooling system equipment having an isolation cooling system, the return line of the residual heat removal system and the return line of the coolant purification system at the time of reactor startup, shutdown, and high temperature periods are connected to the residual heat removal system. Reactor cooling system equipment, characterized in that a flow path communicating with the nuclear reactor is provided through at least one of a low-pressure water injection system of a removal system and the isolation cooling system.