JPS6157891A - Cooling system on suspension 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 provides a method for cooling during controlled reactor shutdown, which improves safety by satisfying the guidelines for separating the safety facility system and the regular system in a nuclear power plant. It's about systems.

[Technical background of the invention and its problems]

Nuclear power plants have an engineering safety facility system that prevents the melting of fuel cladding tubes and prevents external radiation exposure in the event of a reactor accident, and a regular system that controls during normal operation. Generally, they are electrically and mechanically separated and designed so that they do not interfere with each other even in the event of an accident.

The reactor shutdown cooling mode, which is one mode of the reactor residual heat removal system (hereinafter referred to as RHR), which is one of the engineering safety facility systems, cools the reactor during reactor shutdown during normal operation. This mode originally belongs to the commonly used mode.

FIG. 2 is a piping diagram for the current cooling mode during reactor shutdown. The cooling mode during reactor shutdown is to cool the reactor pressure vessel 1 during reactor shutdown by cooling the reactor water from the suction pipe 6 of the coolant recirculation system to the RHR heat exchanger 4 via the RHR pump 3. A system for cooling the reactor by returning reactor water to the reactor pressure vessel 1 via the discharge pipe 7 of the reactor coolant recirculation system and the reactor pressure vessel head spray pipe 5. It is. In this piping route, the reactor coolant recirculation system 2 is a regular system, and includes piping branched from the suction piping 6 of the reactor coolant recirculation system, the HR pump 3, and the RH pump.
Since the piping route from the R heat exchanger 4 to the reactor coolant recirculation system discharge piping 7 is an engineered safety facility system, the cooling mode during reactor shutdown is a mixture of the normal system and the engineering safety facility system. Becomes control.

[Purpose of the invention]

The present invention satisfies the separation guidelines for nuclear power plants and improves safety by moving the cooling mode during reactor shutdown from the engineering safety facility system RJ (R) to the permanent system with equivalent functions. The purpose is to obtain a cooling system during reactor shutdown.

[Summary of the invention]

In order to achieve this purpose, piping is used to return purified and cooled water to the reactor coolant recirculation system discharge piping in the normal reactor coolant purification system (hereinafter referred to as CUW), which maintains the water quality of the reactor water. By adding , it is possible to satisfy the function of cooling mode during reactor shutdown, and it is characterized by being controlled as a complete regular system.

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings.

FIG. 1 is a system configuration diagram showing one embodiment of the present invention, and FIG. 3 is a general piping diagram of a CUW belonging to a regular system. Generally, in a COW, reactor water is passed from the reactor pressure vessel 1 through the suction pipe 6 of the reactor coolant recirculation system to the CUW pump in order to maintain the water quality of the reactor water during normal operation, startup, shutdown, and refueling. 11. CUW via CUW regenerative heat exchanger 8
It passes through the non-regenerative heat exchanger 9 and is cooled in the CUW non-regenerative heat exchanger 9.

The cooled water is put into a filtration and demineralization device 10 for purification.

The purified water is heated again through the CUW regenerative heat exchanger 8. The heated water is delivered to the discharge pipe 7 of the reactor coolant recirculation system.
This system maintains the quality of reactor water by returning it to the reactor pressure vessel 1 through 1 process.

In contrast to such a system, the present invention adopts a cooling system in which pipes 5 and 12 are newly installed in order to satisfy the function of the cooling mode when the reactor is shut down, as shown in Figure 1. By providing the regeneration heat exchanger bypass line 12, the cooled and purified water discharged from the desalination device 10 can be returned to the reactor pressure vessel 1 through the discharge piping 7 of the reactor coolant recirculation system. By branching off the reactor pressure vessel head spray piping 5 from the regenerative heat exchanger bypass line 12, the reactor cooling function of the reactor shutdown cooling mode can be satisfied with the normal system t-trowel. .

Although the above embodiment describes the flow of reactor water using piping diagrams, the equipment and control circuits attached to this system are all commonly used systems.

〔Effect of the invention〕

As described above, according to the present invention, the cooling mode during reactor shutdown can be transferred from the engineering safety facility system to the regular system, making it possible to operate as the original regular system, which is the separation guideline for nuclear power plants. is satisfied and safety is improved.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram showing one embodiment of the present invention;
The figure is a piping diagram for cooling mode during reactor shutdown, and FIG. 3 is a piping diagram for a general reactor coolant purification system. 1...Reactor pressure vessel 2...Reactor coolant recirculation system 3...Book R pump 4...Book heat exchanger 5.
... Reactor pressure vessel head spray piping 6 ... Reactor coolant recirculation system suction pipe 7 ... Reactor coolant recirculation system discharge pipe 8 ... CUW regeneration heat exchanger 9 ... CUW non-regeneration Heat exchanger 10...filtration demineralization device 11...COW pump 12...regeneration heat exchanger bypass line (7317)
Representative Patent Attorney Noriyuki Chika (and 1 other person) Figure 1 JP-A-6L-57891 (3) Figure 2 Figure 3

Claims (1)

[Claims] At the time of reactor shutdown, the reactor coolant purification system has the function of a cooling mode at the time of reactor shutdown in the reactor residual heat removal system, which is one of the engineering safety facility systems of a nuclear power plant. cooling system.