JPS6217692A - Cooling facility on isolation 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 makes it possible to always secure reactor water even if an accident occurs in a nuclear reactor, etc., and to ensure safe operation of nuclear power generation. Concerning improvements to nuclear reactor isolation cooling equipment.

[Technical background of the invention]

General B Nuclear power generation facilities require sufficient attention to ensure their safe operation, and one of these is securing reactor water during reactor isolation in the event of an accident at a nuclear reactor. In order to secure reactor water, nuclear power generation facilities have traditionally had reactor isolation cooling equipment.

This cooling equipment cuts the steam flowing from the reactor to the main steam turbine, and uses the cut steam as driving force for the turbine (also known as the RCIC turbine, which is the prime mover that drives the pump during reactor isolation). Turn the
This power rotates the pump, which draws water from a separate tank, and constantly sends the drawn water to the reactor. This prevents burnout caused by the decay heat of the reactor due to a lack of reactor water. It is intended to prevent

By the way, the cooling equipment for this food has the configuration shown in Fig. 2, and the nuclear reactor shown by reference numeral (1) has a main steam pipe (2).
) is connected to the main steam turbine (not shown) via an isolation valve. In addition, the main steam pipe (2) has a conduit (3) branched in the middle, and this conduit (3) is connected to a steam valve (4).
is connected to the turbine (5) through.

On the other hand, the turbine (5) is equipped with a pump housing directly connected to the shaft, and increases the pressure of water drawn from a separate tank (7) through a conduit (8), converting it into aqua regia through conduit Q21. It is designed to be sent through a control valve (I6) to a nozzle (2) located at the top of the reactor (1). In addition, the steam that has completed its work by the turbine (5) is stored and obtained in the pressure suppression chamber (9) via the conduit (6), and the water cooled here flows to the inlet side of the pump αυ via the conduit Ql. It has become.

The cooling equipment with the above configuration is used in the event of an emergency accident in the reactor (1), and during normal operation (during normal operation), the steam from the reactor (1) is isolated. Valve 1
A so-called closed-loop cycle is configured in which the reactor (1) returns from the water supply pipe α9 to the nuclear reactor (1) via the main steam turbine (not shown).

However, in the above configuration, if an accident occurs in the nuclear reactor or the main steam turbine,
The isolation valve I is closed, and accordingly, steam from the nuclear reactor (1) passes through the conduit (3) and the steam valve (4) to drive the turbine (5). Then, the water in the tank (7) is pumped α1) (
-Therefore, the water is drawn out as pressure water, passes through a conduit a, passes through a control valve ae, reaches a nozzle U3, and is sprayed from there to ensure reactor water. In addition, the above tank (
When the water in 7) is insufficient, water in the pressure suppression chamber (9) is used to secure reactor water for the reactor (1).

[Problems with background technology]

By the way, when an accident occurs in a nuclear reactor or the main steam turbine and the reactor is isolated, the conventional method (:
If water was supplied to the reactor from a separate tank, etc., the humidity inside the reactor would become extremely high, and since the steam generated from inside the reactor already contains a lot of moisture, The exiting steam flows into the turbine (5) in a weighted moisture state containing increasingly more moisture, which may induce erosion of turbine components, such as blades, nozzles, casings, etc.

On the other hand, even during normal operation without isolating the reactor, an accident may occur in a water supply pump, for example, and the water supply pipe Q! If there is a shortage of water sent from 9 to the reactor (1), there is a system that replenishes water from another system to the reactor (1) via the water supply pipe (c). Even if they are used to secure reactor water, the capacity is small and there are problems as it is insufficient to cool the reactor water.

[Purpose of the invention]

Therefore, in light of the above circumstances, the purpose of the present invention is to provide a cooling facility during reactor isolation that allows a sufficient amount of reactor water to be always secured regardless of whether or not the reactor is in isolation operation. do.

[Summary of the invention]

In order to achieve the above object, the present invention provides a bypass pipe in the main line leading from the pump to the reactor 1 through the conduit,
This bypass 萱1 is characterized in that the provided regulating valve, isolation valve and main line control valve are interlocked with each other to ensure that a predetermined amount of reactor water is always maintained. .

[Embodiments of the invention]

The present invention 1: one embodiment will be described below with reference to the drawings.

FIG. 1 shows a schematic diagram of the reactor isolation cooling equipment according to the present invention, in which a turbine (5) is connected in the middle of a conduit (2) connecting the reactor (1) and the isolation valve (t4). The turbine (5) drives a pump directly connected to the shaft.

Pump yield υ is conduit <121. The reactor (1
) is connected to the nozzle u3 located at the top of the pipe.

By the way, in the present invention, a bypass pipe (L7) is provided branching from the conduit a leading from the pump aυ to the nozzle u3, and the bypass pipe (L7) has a control valve α second in the middle thereof, Water pipe Q! JE Connect.

The regulating valve (lI home isolation valve 0 and the control valve (le) are electrically or pneumatically connected to each other, and when the isolation valve I is closed (
When the control valve ae opens, the regulating valve (te) closes, and the isolation valve (L4) opens, and the water supply being sent from the water supply pipe Q9 to the reactor (1): In one case, a so-called reverse action circuit is incorporated in each of the control valves (1 (9, regulating valve -) so that the regulating valve (II) opens and the control valve 16 closes.

Therefore, if an accident occurs in the main steam turbine (not shown) and the isolation valve closes, the closing signal will be sent to the control valve (10E) to open this valve, and also to the left tilt adjustment. and close this valve.Then, tank (7)
Alternatively, the water in the pressure suppression chamber (9) is drawn out by the pump υ, passes through the control valve ae, and is sent from the nozzle αj to the reactor (1
), this ensures that the water is sprayed inside the furnace and cools the inside of the furnace.

On the other hand, when the isolation valve a4 is open, the control tilts to the left;
The regulating valve (18) is closed. In this case, when the water supply sent from the water supply pipe α9 to the reactor (1) is insufficient, a signal from the detector wire is sent to the regulating valve α barrel. As a result of this output signal, the regulating valve aυ is opened, and water from the pump housing is supplied to the reactor (1) for replenishment.
) will be sent to. Therefore, reactor water for the nuclear reactor (1) is secured.

〔Effect of the invention〕

As explained above, the present invention provides a conduit (1) and a bypass pipe (2) for sending water from a turbine-driven pump to the reactor during reactor isolation operation, and the regulating valve (2) provided in this bypass pipe (2) is arranged in the opposite direction to the isolation valve and the control valve. Since they are connected in an operational relationship, even if there is a shortage of reactor water in the reactor, sufficient reactor water can be secured, and as a result, the reactor can continue to operate safely without tripping.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of a reactor isolation cooling facility according to the present invention, and FIG. 2 is a schematic system diagram showing a conventional embodiment. 1... Nuclear reactor 5... Turbine 7...
Tank 9 - Pressure suppression chamber 11... Pump 12 - Conduit 14 - Isolation valve
15-Water supply pipe 16...Control valve 17-Bypass pipe 18...Adjustment valve Representative Patent attorney Noriyuki Chika Yudo Hirofumi MikiFigure 1

Claims (3)

[Claims] (1) It has a pump driven by the steam turbine of a steam turbine whose driving force is steam from the nuclear reactor, and the pump supplies water drawn from a separate tank to the nuclear reactor; A cooling facility for reactor isolation, which secures reactor water during reactor isolation or when there is a shortage of water supply to the reactor, characterized in that a bypass pipe is provided branching off from the conduit leading from the pump to the reactor. (2) The reactor isolation cooling equipment according to claim 1, wherein the bypass pipe is connected to a water supply pipe that supplies water to the reactor. (3) It has a pump driven by the steam turbine of a steam turbine whose driving force is steam from the nuclear reactor, and the pump supplies water drawn from a separate tank to the nuclear reactor; In a device that secures reactor water during reactor isolation or when there is a shortage of water supply to the reactor, an isolation valve on the way from the reactor to the main turbine, and a first valve arranged in a conduit from the pump to the reactor; and a second valve disposed on a bypass pipe that branches into a conduit leading from the pump to the reactor, and when the isolation valve is closed, the first valve is opened, and when the isolation valve is open, the second valve is opened. A nuclear reactor isolation cooling equipment characterized by opening a valve of the reactor.