RU153272U1 - ENERGY INSTALLATION - Google Patents

Abstract

1. Power plant containing a steam generator with heating and heated paths, the first of which is connected to a heat source with the formation of the first circuit, and the heated steam generator path is connected to a passive heat removal system, a pumped storage tank connected to the first circuit, the latter being located under a sealed heat-insulated a containment shell, characterized in that the inner cavity of the containment shell is additionally equipped with a sealed partition dividing it into two parts - an emergency room and a gas containment room, in which there are channels communicating them for directing the steam-air mixture and a steam condensation device made in the form of a bubbler. 2 ... Power plant according to claim 1, characterized in that the gas containment room is located around the emergency room.

Description

The inventive utility model relates to the field of nuclear energy and can be used in nuclear power plants with water-type reactors.

A known system of passive heat removal from the protective shell, consisting of a heat exchanger connected to the tank with a supply of coolant through the inlet and outlet pipes, the tank’s feed pipe is equipped with a steam receiver located in the tank with a supply of coolant and consists in organizing circulation along the cooling circuit so that until the water temperature in the tank reaches temperatures close to the saturation line at atmospheric pressure, there was no boiling of cooling water in the heat exchanger and condensation water hammer in the system circuit was excluded. (See utility model certificate No. 85029, IPC G21C 15/18, 2006)

The disadvantages of this technical solution are:

- the need for systems of an active principle of operation and emergency measures to prevent the complete drainage of the primary circuit and to put the power plant in a safe state, due to the fact that the passive heat removal system from the containment, reducing the pressure in the emergency room, intensifies the flow of the primary coolant from the gap;

- the need to create a large volume of subshell space to compensate for the "volley" discharge of the primary coolant when the primary circuit is ruptured with a full cross section;

- increased leakage of radioactive vapor-gas medium into the environment due to increased pressure in the protective sheath;

- increased formation of explosive explosive mixtures when hydrogen escapes into the emergency room during the “severe” accident, which is due to the fact that the passive heat removal system from the containment, condensing the steam generated during the first circuit, reduces the amount of the phlegmizer of the hydrogen combustion reaction by which this steam is.

The closest to the claimed utility model is a power plant (See Patent No. SU 1681032, IPC 5 F01K 13/02 of 04/04/1989) containing a steam generator with heating and heated paths, the first of which is connected to the heat source by circulation pipes to form the primary circuit and the heated path of the steam generator is connected to the air condenser of the passive heat removal system, a pumped storage tank connected to the first circuit, the latter being placed under a sealed thermally insulated protective shell.

This technical solution allows to overcome the emergency situation in a power plant with a water-type nuclear reactor when the primary circuit breaks without radioactivity exceeding the limits established by the standards, using only means based on passive principles, while due to the fact that the steam generated when the first the circuit into the protective shell does not condense, the possibility of explosive explosive mixtures when the hydrogen escapes into the emergency room during the “heavy” waria is reduced.

The disadvantages of this technical solution are:

- the need to create a large volume of subshell space, since before the pressure is equalized inside the primary circuit and the containment, the coolant expires, part of which evaporates, increasing the pressure inside the containment due to the absence of a special steam condensation system inside the containment to ensure its tightness

- increased leakage of radioactive vapor-gas medium into the environment due to increased pressure in the protective sheath.

- the possibility of explosive explosive mixtures in a "severe" accident.

The technical task is to create a technical solution to overcome the emergency in a power plant with a water-type nuclear reactor when the primary circuit breaks.

The technical result of solving this problem is to increase the safety of the power plant, namely, to reduce leaks of the radioactive vapor-gas medium outside the containment and to reduce the possibility of explosive concentrations of explosive mixtures formed when hydrogen escapes during a “severe” accident with a decrease in the dimensions of the containment.

The problem is solved in that in a power plant containing a steam generator with heating and heated paths, the first of which is connected to a heat source with the formation of the first circuit, and the heated path of the steam generator is connected to a passive heat removal system, a pumped storage tank connected to the first circuit, the last placed under a sealed thermally insulated protective shell, the inner cavity of the protective shell is additionally equipped with a sealed partition dividing it into two parts - emergency the room and the gas localization room in which the channels communicating them are arranged for directing the vapor-air mixture and the steam condensation device, made in the form of a bubbler.

The gas containment room is located around the emergency room.

This technical solution allows, due to the condensation of the steam generated during the flow of the primary circuit coolant during pressure equalization of the primary circuit and the inner cavity of the protective shell, to provide a decrease in volume in this cavity relative to the prototype. Another advantage of this technical solution is that due to the presence of a condensation device made in the form of a bubbler, it is possible to reduce the radioactivity of the leakage of the gas mixture and to reduce the possibility of the formation of an explosive mixture during the release of hydrogen during a severe accident due to the localization of a significant part of the air in the gas localization room, and in the emergency room, where hydrogen escapes in the event of a "severe" accident, there is mainly steam and thus the conditions for the formation of an explosive mixture are excluded.

The essence of the technical solution is illustrated by the drawing shown in FIG.

The power plant consists of a steam generator (1) with heating and heated paths, the first of which is connected to a heat source (2) with the formation of the primary circuit (3), and the heated path of the steam generator by pipelines (4) is connected to a passive heat removal system (5), a storage tank (6) connected to the first circuit (3) by a pipeline (7) with a non-return valve (8) installed on it. The power plant is placed under a sealed thermally insulated protective shell (9). The inner cavity of the protective shell is additionally equipped with a sealed partition (10), dividing it into two parts - the emergency room (11), where all the equipment of the primary circuit is located, and the gas localization room (12), communicated by the channel (13) for directing the vapor-air mixture and the device steam condensation (14), made in the form of a bubbler, and the gas localization room (12) is located around the emergency room (11), and the steam condensation device (14) and the channel (13) are located inside the gas localization room (12).

The technical solution works as follows.

Initially, the power plant is operating normally. In the rooms inside the containment (11, 12), temperature, pressure and humidity have the specified parameters. The device for condensation of steam (14) has a regular supply of water. The steam generator (1) operates in the steam generation mode, the passive heat removal system (5) is disconnected from the steam generator and is in standby mode. The storage tank (6) due to the fact that the pressure in it is lower than the pressure in the primary circuit (3) is disconnected from the primary circuit (3) by a check valve (8).

When an initial event occurs, depressurization of the primary circuit (3), the coolant of the primary circuit (3) flows into the emergency room (11). This leads to a decrease in the pressure of the primary circuit below the emergency protection settings and causes: emergency protection operation (suppression of the nuclear fission reaction); inclusion in the system of passive heat removal (5); connection of the storage tank (6). Also, the outflow of the primary coolant to the emergency room (11) leads to an increase in pressure, as a result of which through the channel (13) the vapor-gas medium passes from the emergency room (11) to the condensation device (14), where the steam condenses and the gas sparged through a layer of water enters the gas localization room (12).

After passing through dynamic processes, the following state is established. In the power plant, the level of the primary coolant is established, which is maintained by recharge from the pumped storage tank (6). The level of the primary coolant in the power plant is maintained sufficient for the development of a single-phase (water) natural circulation of the coolant in the primary circuit (3) through a heat source (2) and a steam generator (1). With the developed level of natural circulation of the primary coolant (3), the passive heat removal system (5) effectively removes heat from the primary circuit through the steam generator (1). The vapor-gas medium from the emergency room (11) enters the gas localization room (12) through the condensing device (14), while the gas leaves the gas localization room (12), and the steam condenses, heating up the water supply in the condensing device (14).

During the initial phase of the accident, the pressure in the primary circuit decreases due to the outflow of the primary coolant, and the pressure in the rooms under the containment increases for the same reason. As a result, the pressure in the primary circuit is equalized with the pressure inside the containment shell (9). At this point in time, the power of the residual heat is aligned with the power of the exhausted system of passive heat removal (5). The combination of two factors: the absence of a pressure differential between the primary circuit (3) and the containment (9) and the equality of the residual heat power generated in the heat source (2) of the power of the passive heat removal system (5), leads to the cessation of the flow of the primary coolant from the gap in emergency room (11). The volume of water stored in the condensation device (14) limits the pressure inside the protective shell (9) to a value sufficient to organize the required heat removal through the passive heat removal system (5) after draining the storage tank (6).

Subsequently, the power removed from the primary circuit (3) through the steam generator (1) to the passive heat removal system (5) begins to exceed the residual heat generated in the heat source (2). The parameters of the primary circuit (pressure, temperature, etc.) begin to decrease, which leads to a decrease in the parameters in the protective shell (9) (due to heat and mass loss from the protective shell (9)). Since the protective sheath (9) is made of high-density and thermally insulated, the rate of decrease in the parameters of the primary circuit exceeds the rate of decrease in the parameters in the protective sheath (9). Thus, the pressure in the protective shell (9) and the primary circuit (3) is maintained above the saturation pressure at the temperature of the primary circuit at the outlet of the heat source (2), which leads to the absence of boiling and, as a consequence, the absence of the primary coolant flowing into the emergency room ( eleven).

After passing through all phases of the emergency process, the installation goes to the next final state. The power plant is muffled and dampened to a cold state due to the operation of the passive heat removal system (5). The primary coolant level (3) is sufficient for the existence of a single-phase natural circulation of the primary coolant through a heat source (2) and a steam generator (1). The pressure of the primary circuit and the pressure in the containment are equal to atmospheric (or slightly higher due to gas dissolution when using the gas pressure compensation system in the reactor installation). The removal of residual heat is carried out during natural single-phase circulation of the primary coolant (3) and the passive heat removal system (5).

Thus, this technical solution allows you to:

- to ensure the transition of the power plant to the final safe state, using only passive systems and devices, with a smaller volume of rooms under a protective sheath;

- reduce the likelihood of explosive concentrations of explosive mixture during the release of hydrogen during a "severe" accident, due to the separation of steam and gas in a bubbler. Gas is concentrated in the gas localization room, and in the emergency room, where in the event of a “severe” accident, hydrogen is released, there is mainly steam;

- to reduce the projected emission of activity due to the fact that the active gas-vapor medium is bubbled through the water layer of the condensing device, and also due to the fact that the gas localization room is located around the emergency room, as a result of which the atmosphere of the gas localization room is in contact with the wall of the containment .

Claims (2)

1. Power plant containing a steam generator with heating and heated paths, the first of which is connected to a heat source with the formation of the first circuit, and the heated path of the steam generator is connected to a passive heat removal system, a storage tank connected to the first circuit, the latter being placed under a sealed heat-insulated protective shell, characterized in that the inner cavity of the protective shell is additionally equipped with a sealed partition dividing it into two parts - emergency eschenie gas and localization of the room in which they are placed reporting channels for guiding the air-steam mixture, and steam condensation device formed as a bubbler. 2. Power plant according to claim 1, characterized in that the gas localization room is located around the emergency room.

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