JPH1090468A - Emergency core cooling system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To simplify the equipment while ensuring multiplexing and providing diversity in the configuration of a heat removal system, a low-pressure water injection system, an emergency power supply, and a system division. Provided is an emergency core cooling device that can achieve both reliability and economy. SOLUTION: Two systems of HPCFs 11 and 12 and one system of R are provided.
CIC 21, 2 systems of LPFLs 31, 32, 1 system of core flooding system 41, steel containment vessel 51, containment outer peripheral pool 52, and emergency diesel generators 61, 62, 6
3 is comprised. Emergency diesel generator 61,
62 is a high pressure water injection system 11 or 12 and a low pressure water injection system 31
Alternatively, it is formed so as to supply a power supply capacity capable of performing both of the 32 operations. The emergency diesel generator 63 is formed so as to supply the minimum necessary power capable of operating the RCIC 21, the static containment vessel heat removal and injection device 53, and the recirculation core flooding system 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an emergency core cooling system, and more particularly to an emergency core cooling system of a nuclear reactor for guiding a reactor to a safe state when an abnormal event occurs in a BWR plant. .

[0002]

2. Description of the Related Art In general, various safety devices are provided in a nuclear power plant so that the reactor can be brought into a safe state even if various abnormal events occur. In addition, it is confirmed that each safety device is arranged in consideration of safety, multiplicity, and economy in the event of an abnormality, and has sufficient safety.

An emergency core cooling apparatus of this kind which has been generally employed in the past is, for example, a two-system high-pressure water injection apparatus (hereinafter referred to as an HPFL apparatus) as described in Japanese Patent Application Laid-Open No. 62-217193. One system is provided with a high-pressure core water injection device (hereinafter referred to as an HPI device), two systems are provided with a low-pressure core spray device (hereinafter referred to as an LPCS device), and one system is provided with a low-pressure water injection device (hereinafter referred to as an LPFL device). Normal.

Usually, each of the above HPFL devices, LP
The CS device and the LPFL device have a motor-driven pump, and the HPI device has a turbine-driven pump. Further, each of the LPCS device and the LPFL device has a heat exchanger (cooler) that functions as a residual heat removal system (RHR).

[0005] The emergency core cooling device has three diesel generators as emergency power supplies in case the normal drive power supply is lost. Each HPFL device, LPCS device,
The pump of the LPFL device is driven by these diesel generators. Further, the emergency core cooling device includes a first section having an HPFL apparatus and an LPCS apparatus, a second section having an HPFL apparatus and an LPCS apparatus, and an HPI section.
The device is divided into three sections, namely a third section having an apparatus and an LPFL apparatus. Usually, one diesel generator is assigned to each section.

[0006]

The emergency core cooling device thus formed is required not only to have high reliability but also to bring out the maximum effect with a necessary minimum capacity. In particular, improvements in economy and performance have been pursued.

In the above prior art, the high pressure water injection system, the low pressure water injection system, the heat removal system, and the power supply system of the emergency core cooling system are assigned to three sections, and the HPFL device and HPCI device in the high pressure water injection system are driven by a pump drive source. In order to secure not only multiplicity but also diversity. However, the RHR, which is a heat removal system, has three similar systems in three sections, and the diesel generator, which is a power supply system, has three similar systems in three sections. Although the system has multiplicity as the number of systems, it does not have diversity as a device.

The present invention has been made in view of the foregoing, and an object of the present invention is to provide a system using a containment heat removal system which is a static heat removal system in addition to a dynamic heat removal system RHR. This type of emergency core cooling system is provided, which is capable of simplifying the system with diversity while ensuring multiplexing in the configuration of the sections, and consequently achieving both reliability and economy. Is to do.

Further, a second object of the present invention is to adopt an emergency core cooling system having a multiplicity and diversity in a low-pressure core cooling system by adopting a core flooding system in one of three low-pressure core cooling systems. It is to provide a device. Further, a third object of the present invention is to provide an emergency core having versatility and diversity using a small-capacity diesel generator in addition to a large-capacity diesel generator used in a general emergency core cooling device. It is to provide a cooling device.

[0010]

That is, the present invention provides an emergency core cooling system including a high-pressure core cooling system, a low-pressure core cooling system, a residual heat removal system, and a first emergency power supply for supplying power thereto. A first system configuration, a second system configuration including a high-pressure core cooling system, a low-pressure core cooling system, a residual heat removal system, and a second emergency power supply for supplying power thereto, and are driven by a turbine. High pressure core cooling system, containment vessel heat removal / water injection system for injecting coolant into the space formed between the containment vessel and the living body shielding wall, and a third emergency power supply for supplying power to the containment vessel heat removal / water injection system And a third system configuration including the connection device, thereby achieving the intended purpose.

[0011] That is, HPCF and RHR are installed respectively in the divisions I and II of the emergency reactor cooling system, and in the division III, a reactor isolation cooling system (hereinafter referred to as RCIC system), a steel containment vessel and a living body. By the containment vessel heat removal water injection system that injects coolant into the space formed in the space with the shielding wall,
The present invention is designed to remove residual heat when an abnormality occurs in a nuclear reactor, thereby improving the reliability of an emergency core cooling device.

In order to achieve the second object,
The present invention is based on the classification of emergency reactor cooling system
FL equipment is installed, and core flooding system is installed in Category III.
For this reason, the pump of the LPFL apparatus and the pump of the core flooding system are provided with a low-pressure water injection apparatus having a variety due to different capacities.

Further, in order to achieve the third object,
Emergency reactor cooling system categories I and II are equipped with large capacity diesel generators to operate the HPFL, LPFL and RHR existing in categories I and II. By installing a small-capacity diesel generator to operate the heat removal and injection system for the containment vessel, the system is equipped with an emergency core cooling system that minimizes the system capacity while having both versatility and diversity. .

That is, the emergency core cooling device thus formed is classified into emergency reactor safety device categories I and II.
Equipped with a HPFL device, LPFL device, RHR, and diesel generator, and in the third category, RCIC device, recirculation core flooding maintenance device, static containment heat removal water injection device, static containment heat removal device, small capacity diesel It is equipped with a generator, and is equipped with a high-pressure water injection device, a low-pressure water injection device, a residual heat removal device, and a power supply independently in three sections, so that the safety of the reactor can be improved.

Further, in the present invention, a static containment heat removal device is installed in the category III, thereby eliminating one RHR and reducing the capacity of the diesel generator, thereby maintaining high safety. The economy can be improved, and the pump of the high pressure water injection system is motor driven and turbine driven,
Pumps for low-pressure irrigation systems have large and small capacities, dynamic and static devices for residual heat removal, and large and small capacity diesel generators for power supply. Can be improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 systematically shows a first embodiment of the emergency core cooling system. In this embodiment, two systems of HPCFs 11 and 12 and one system of RCIC2
1 and 2 LPFLs 31 and 32, 1 system core flooding system 41, steel containment vessel 51, containment vessel outer peripheral pool 52,
And emergency diesel generators 61, 62, 63 and a condensate storage tank 71.

The emergency diesel generators 61 and 62 include a high-pressure water injection system 11 or 12 and a low-pressure water injection system 31 or 3.
Both are designed to provide a power supply capacity that allows both operations. Emergency diesel generator 63 is RCIC2
1. It is designed so as to supply the minimum necessary power supply capacity that allows the operation of the three systems of the containment vessel heat removal / water injection pump 53 and the core flood pump 41.

The above configuration of the present embodiment is a structure having independence so that the safety function of the device can be achieved even if a single failure is assumed, and the power source, the pump, the pump control member, and all other devices are I / O. Pipes 13 and 1 for transferring coolant to each section with three sections consisting of section, section II and section III
5. Piping 16, 17 connected to the condensate storage tank 71
And a high-pressure core water injection system composed of a high-pressure water injection system pump 11 and 12, or a turbine-driven high-pressure water injection system composed of a pipe 23 connecting the pipe 22 and the condensate storage tank 71, and an RCIC pump 21.

One of the driving sources of the high-pressure core water injection pumps 11, 12 is shared with the RCIC pump 21, and is driven by a steam turbine so as to cope with a reactor shutdown state when all power is lost. On the other hand, when the external power supply is lost during LOCA, the high-pressure water injection pump 11 or 12 supplies power from the in-house power supply to the emergency diesel generator 61.
Alternatively, the motor is driven so that it can operate even if it is changed to 62. In addition, by installing two high-pressure core water injection systems, even if a single failure is assumed, the high-pressure water injection cooling function can always be maintained.

Further, the two systems of the pipes 35 and 36 and the low-pressure water injection pumps 31 and 32 are shared with an RHR (residual heat removal system) pump. As a result, the function of flooding the reactor core during an accident is exhibited, and the decay heat when the reactor is stopped is removed by the heat exchangers 33 and 34 of the low-pressure water injection system. One low-pressure water injection system 41 has a function of a core flooding system by reducing the capacity of the pump.

Next, a system for removing residual heat will be described below. Two low pressure core injection pumps 31, 32
Shares a function with the residual heat removal system. Further, as a system for removing residual heat, there is a containment container heat removal system composed of a pipe 55 connected to the condensate storage tank 71 and a containment container heat removal water injection pump 53. Water is stored in the outer peripheral pool 52 of the containment vessel by the containment vessel heat removal pump 53 to remove heat from the wall of the containment vessel. As a result, the residual heat removing function of the residual heat removing system has a variety of functions.

In FIG. 1, two high pressure water injection pumps 1 are shown.
Pump 2 for cooling system at the time of reactor isolation of 1, 12 and 1 system
1. A pump 41 of a core flooding system of one system, a residual heat removal system using heat exchangers 33 and 34 which are also used as pumps 31 and 32 of a two-system low pressure water injection system, and an outer peripheral pool of a steel containment vessel 51 A combination of emergency diesel generators 61, 62, and 63 required when the power supply is lost is shown for a containment heat removal system that injects water into 52 and removes residual heat.

In the I and II categories, electric-driven high-pressure core water injection pumps 11 and 12 and electric-drive low-pressure core water injection pumps 31 and 32 which are also used as a residual heat removal system are arranged, and are necessary for the operation of these devices. Emergency diesel generators 61 and 62 having the following capacity are arranged. On the other hand, in the III category, a core flooding system constituted by a turbine-driven high-pressure water injection pump 21 also serving as an RCIC, a pipe 42 having a pump having a smaller capacity than one LPFL, and a core flooding pump 41, A pipe 55 for storing water in the outer peripheral pool 52 and a containment heat removal / water injection pump 53 are provided, and an emergency diesel generator 63 having a capacity required for operation of these devices is provided.

In the section III, the number of pumps and the pump capacity are smaller than those in the sections I and II, so that the electric load is reduced, and power can be supplied by a small-capacity diesel generator such as an air-cooled diesel generator.

As described above, the reactor core cooling system for a nuclear reactor according to the present embodiment is formed so as to be capable of independently injecting water in three systems as a high-pressure water injection system, and to be capable of injecting water independently in three systems as a low-pressure water injection system. The emergency diesel generator at the time of power loss is formed so that the residual heat can be removed independently in the system in which the two heat exchangers 33 and 34 are arranged as the residual heat removal system and in the containment heat removal system. Two large-capacity diesel generators 61 and 62 and one small-capacity diesel generator 63 are arranged. Classes I and II are filled with a large-capacity diesel generator, and class III is a small-capacity diesel generator. It is formed so that the capacity can be filled by the machine.

Therefore, the reliability and safety of the plant can be greatly improved without lowering the core cooling capacity, and the cost related to the ECCS can be reduced by eliminating one heat exchanger and adopting a small-capacity diesel generator. It can be significantly reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, in addition to the configuration of the embodiment of FIG. 1, the containment vessel heat removal / water injection system pump 53 is a diesel-driven pump. With this configuration, the power load of the category III is only the core flooding system, and the power supplied by the air-cooled small-capacity emergency diesel generator 63 is used only by the core flooding system.

Therefore, the reliability and safety of the plant can be greatly improved without lowering the core cooling capacity, and the cost relating to the ECCS can be reduced by eliminating one heat exchanger and employing a small capacity diesel generator. It can be significantly reduced.

A third embodiment of the present invention will be described with reference to the drawings. In FIG. 3, in addition to the configuration of the embodiment of FIG. 1, a containment container heat removal system is provided with a containment container upper cooling device 54. The containment vessel upper cooling device 54 branches off from the containment vessel heat removal water injection pump 53 and has a configuration in which a ring-shaped water injection pipe 56 is provided at the top of the steel containment vessel 51. The design is such that cooling water always flows when water injection is performed.

With this configuration, even in the event that the heat removal system using the dynamic equipment does not function, the heat can be removed from the outer peripheral pool 52 of the containment vessel and the surface of the steel containment vessel 51, and the containment vessel can be removed. Can be prevented from increasing remarkably.

As described above, the emergency core cooling device thus formed is provided with a high-pressure water injection device, a low-pressure water injection device, a residual heat removal device, and a power source independently in three sections. Therefore, the safety of the reactor can be improved.

[0032]

As described above, according to the present invention, it is possible to obtain an emergency core cooling device capable of greatly improving the reliability and safety of a plant and reducing the cost related to ECCS. it can.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a first embodiment of an emergency core cooling device of the present invention.

FIG. 2 is a system diagram showing a second embodiment of the emergency core cooling device of the present invention.

FIG. 3 is a system diagram showing a third embodiment of the emergency core cooling device of the present invention.

[Explanation of symbols]

11, 12 ... high-pressure core injection pump, 21 ... reactor isolation cooling system pump, 31, 32 ... low-pressure core injection pump,
33, 34: residual heat removal system heat exchanger, 41: core flooding pump, 51: steel containment vessel, 52: containment outer peripheral pool, 53: containment vessel heat removal / water injection pump, 54: containment vessel upper cooling device .

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Masayoshi Matsumoto 3-1-1, Sakaicho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Plant

Claims (4)

[Claims] 1. A first system comprising a high-pressure core cooling system, a low-pressure core cooling system, a residual heat removal system, and a first emergency power supply for supplying power thereto, a high-pressure core cooling system, and a low-pressure core cooling. System, a residual heat removal system, and a second system configuration including a second emergency power supply for supplying power thereto, and a high-pressure core cooling system driven by a turbine, a containment vessel and a living body shielding wall. A containment vessel heat removal / water injection system for injecting coolant into the formed space, a third emergency power supply for supplying power to the containment vessel heat removal / water injection system, and a third equipped with a connection device therefor
An emergency core cooling device comprising a system configuration. 2. A core flooding system is provided in the third system configuration, and a third emergency power supply unit that supplies power to the core flooding system when a normal power supply is lost to the core flooding system is provided. Emergency core cooling system. 3. The emergency core cooling device according to claim 2, wherein the first and second emergency power supply devices are water-cooled diesel generators, and the third emergency power supply device is an air-cooled diesel generator. 4. The emergency core cooling device according to claim 2, wherein the pump of the containment vessel heat removal and injection system in the third system configuration is driven by using an internal combustion engine.