WO2014090106A1

WO2014090106A1 - High-pressure safe injection system for nuclear power stations

Info

Publication number: WO2014090106A1
Application number: PCT/CN2013/088601
Authority: WO
Inventors: 任云; 赖建永
Original assignee: 中国核动力研究设计院
Priority date: 2012-12-11
Filing date: 2013-12-05
Publication date: 2014-06-19
Also published as: ZA201504982B; CN103871506B; AR093899A1; GB2523949A8; GB2523949B; CN103871506A; GB201512027D0; GB2523949A

Abstract

A high-pressure safe injection system for nuclear power stations is configured on multiple loops (5) of a loop system of a reactor. The high-pressure safe injection system comprises at least one boric acid injection unit (15) and at least one coolant injection unit (16). The boric acid injection unit (15) comprises a concentrated boric acid injection box (8) and a concentrated boric acid injection pipeline (7). One end of the concentrated boric acid injection pipeline (7) is connected to the concentrated boric acid injection box (8), and the other end of the concentrated boric acid injection pipeline (7) penetrates into a containment vessel (11) and then is connected to a cold tube section (501) of a loop (5) of a loop system of the reactor. The coolant injection unit (16) comprises a water source (14) and a coolant injection pipeline (6) connected to the water source (14). The coolant injection pipeline (6) comprises a cold tube section injection pipeline (9) and a heat tube section injection pipeline (10) that are connected in parallel; the cold tube section injection pipeline (9) penetrates into the containment vessel (11) and then is connected to a cold tube section (501) of a loop (5) of a loop system of the reactor; and the heat tube section injection pipeline (10) penetrates into the containment vessel (11) and then is connected to a heat tube section (502) of a loop (5) of a loop system of the reactor. Multiple pipelines of the injection system are not mutually interfered, thereby facilitating flow control; and the injection system has high security.

Description

Nuclear power plant high pressure safety injection system

Technical field

The invention relates to the field of pressurized water reactor nuclear power plants, and particularly relates to a high pressure safety injection system for a pressurized water reactor nuclear power plant.

Background technique

In the PWR nuclear power plant, the safety injection system performs the emergency cooling function of the core in the event of a main coolant pipe or main steam pipe breakage accident, and is one of the important special safety facilities. In previous designs, the high pressure injection system utilized two of the three charge pumps of the chemical and volume control system as an injection pump. The injection flow rate of each injection pump is distributed through a parent tube and then distributed to the cold and hot sections of each loop. Such a design will affect the flow of other injection pipelines when one injection pipeline fails. A concentrated boric acid injection tank is installed in the high-pressure injection system. Only one injection line is injected into the tank through the concentrated boric acid solution, and the concentrated boric acid solution is injected into the primary circuit to maintain the core in a subcritical state. If this line fails, this feature is not possible and the emergency cooling capacity of the safety injection system is reduced.

Summary of the invention

The technical problem to be solved by the present invention is to provide a nuclear power plant safety injection system capable of independently injecting cooling water into a reactor primary circuit, improving the reliability of the system operation, and strengthening the ability of the safety injection system to perform core emergency cooling; The separately set concentrated boric acid injection series injects the boric acid solution into the core under the action of the non-safe injection system to provide sufficient negative reactivity to achieve shutdown.

In order to solve the above technical problem, the technical solution of the present invention is a high-voltage safety injection system for a nuclear power plant, which is disposed on several loops of a primary circuit of the reactor, including at least one boric acid injection. Incoming unit and at least one coolant injection unit;

The boric acid injection unit comprises a concentrated boric acid injection tank, a concentrated boric acid injection pipeline connected at one end to the concentrated boric acid injection tank, and the other end of the concentrated boric acid injection pipeline penetrates the safety shell and is connected to one of the reactor primary loop systems. Cold pipe section of the loop;

The coolant injection unit includes a water source and a coolant injection pipeline connected to the water source; the coolant injection pipeline includes a parallel cold pipe section injection pipeline and a heat pipe section injection pipeline; the cold pipe section injection pipe The road penetrates the containment and is connected to the cold pipe section of a loop of the reactor primary loop system; the heat pipe section injection pipe penetrates the containment vessel and is connected to the heat pipe section of a loop of the reactor primary circuit.

The water source may be a refueling water tank in the containment.

The concentrated boric acid injection line is provided with a boric acid injection pump; and the coolant injection line is provided with a high pressure injection pump.

The reactor primary loop system includes three loops.

The three loops are configured with four coolant injection units, wherein two coolant injection units are independently connected to the first loop and the second loop of the three loops of the reactor; The cold pipe section injection line of the coolant injection unit is connected to the cold pipe section on the third of the three loops of the reactor, and the heat pipe sections of the other two coolant injection units are injected together Connected to the heat pipe section on the third of the three loops of the reactor.

The three loops of the reactor are provided with two boric acid injection units, and the cold tube sections of the three loops are connected by a single mother tube; the concentrated boric acid injection lines of the two boric acid injection units are connected to the mother tube The concentrated boric acid injection pipeline of the two boric acid injection units is connected through a communication pipeline, and the communication pipeline is provided with an isolation crucible. The beneficial effects of the invention:

(1) A plurality of high-pressure injection lines are injected into the cold and hot sections of the multiple loops of the primary loop system, and the multiple pipelines do not interfere with each other, which facilitates flow regulation;

(2) Intensive boric acid is injected into the primary circuit by an independent concentrated boric acid injection system after the injection signal is issued. This function does not depend on the operation of the high pressure injection pump and the associated injection line;

(3) After the shutdown signal is issued, and the control rod fails to be inserted and the reactor cannot be shut down, the boric acid injection pump is automatically started, and the high concentration of boron water injected into the tank into the core is injected into the core to introduce sufficient negative Reactivity to achieve shutdown.

DRAWINGS

Figure 1 is a schematic diagram of a loop in a primary loop system of a nuclear power plant reactor;

2 is a schematic view of a nuclear power plant high pressure safety injection system according to the present invention;

Figure 3 is a partial schematic view of a nuclear power plant high pressure safety injection system applied to a three-loop reactor according to the present invention;

Figure 4 is a partial schematic view of a nuclear power plant high pressure safety injection system applied to a three-loop reactor in accordance with the present invention;

Figure 5 is a partial schematic view C of a nuclear power plant high-pressure safety injection system applied to a three-loop reactor according to the present invention;

In the figure: 1-reactor core, 2-pressure vessel, 3- steam generator, 4-pump, 5-loop, 6-coolant injection line, 7-concentrated boric acid injection line, 8-concentrated boric acid injection Box, 9-cold pipe section injection line, 10-heat pipe section injection line, 11-safety shell, 12-boric acid injection pump, 13-high pressure injection pump, 14-water source, 15-boric acid injection unit, 16-coolant Injection unit, 17-isolation 18, 18-connected line, 19-mother tube.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be further described with reference to the accompanying drawings and embodiments.

The nuclear power plant reactor includes a primary circuit system, and the primary circuit system includes three loops 5, FIG. One of the loops 5 is shown; each loop includes a heat pipe section 502 and a cold pipe section 501; the coolant enters the pressure vessel 2 from the cold pipe section 501 through the pump 4 and extracts heat from the core 1, and the coolant after drawing heat Leaving the pressure vessel 2, the heat pipe section 502 releases heat through the steam generator 3, and the released heat is returned to the cold pipe section 501 to enter the pressure vessel 2 again to achieve circulation;

As shown in FIG. 2, a nuclear power plant high pressure safety injection system of the present invention includes at least one boric acid injection unit 15 and at least one coolant injection unit 16;

The boric acid injection unit 15 includes a concentrated boric acid injection tank 8 and a concentrated boric acid injection line 7 connected at one end to the bottom of the concentrated boric acid injection tank 8. The other end of the concentrated boric acid injection line 7 penetrates through the penetration member. The shell 11 is connected to a cold tube section 501 of a loop 5 of the reactor primary loop system; the concentrated boric acid injection line 7 is provided with a boric acid injection pump 12;

The coolant injection unit 16 includes a water source 14 and a coolant injection line 6 connected to the water source 14; the coolant injection line 6 includes a parallel cold pipe section injection line 9 and a heat pipe section injection line 10 The cold pipe section injection pipe 9 penetrates the safety casing 11 through the penetration member and is connected to the cold pipe section 501 of a loop 5 of the reactor primary circuit; the heat pipe section injection pipe 10 penetrates the safety casing 11 through the penetration member. And connected to the heat pipe section 502 of a loop 5 of the primary circuit of the reactor; the coolant injection pipeline 6 is provided with a high pressure injection pump 13; the water source 14 may be a refueling water tank in the safety enclosure 11;

As shown in FIG. 3 to FIG. 4, three loops 5 of the reactor are arranged with four coolant injection units 16, wherein two coolant injection units 16 are independently connected to the third of the three loops 5 of the reactor. One and the second; the cold pipe section injection line 9 of the other two coolant injection units 16 is connected to the cold pipe section 501 on the third of the three loops 5 of the reactor, the other two The heat pipe section of the coolant injection unit 16 is injected into the pipe 10 - and connected to the third of the three loops 5 of the reactor Upper heat pipe section 502.

As shown in FIG. 5, the three loops 5 of the reactor are provided with two boric acid injection units 15, and the cold tube segments 501 of the three loops 5 are connected by a single mother tube 19; the two boric acid injection units 15 The concentrated boric acid injection line 7 is connected to the mother tube 19; the pipeline section between the high pressure injection pump 13 and the concentrated borate tank 8 on the concentrated boric acid injection line 7 of the two boric acid injection units 15 passes A communication line 18 is connected, and the communication line 18 is provided with an isolation crucible 17.

Specific work items:

(1) Safe injection process

The following actions are performed as soon as the signal is received:

A) Start 4 high pressure injection pumps on the 4 coolant injection units 16;

B) start two boric acid injection pumps A and B;

During the injection phase, the reactor coolant pressure drops rapidly, injecting boron-containing water into the cold section 501 of a loop 5 of the primary loop system and into the reactor core.

The input of the high pressure injection pump 13 and the boric acid injection pump 12 refills the reactor pressure vessel and submerges the reactor core.

Simultaneous injection of cold tube section 501 and heat pipe section 502 ensures that the boron concentration of the core is below its solubility limit.

During the long-term injection phase, the safety injection system still maintains a simultaneous injection into the hot and cold sections until:

A) complete core cooling;

B) Environmental conditions (pressure, temperature and radioactivity levels) allow access to the containment.

(2) Concentrated boric acid injection shutdown The boric acid injection subsystem is used as a second shutdown when the reactor needs to be shut down and the control rod fails. When the reactor protection system issues a shutdown signal and the control rod fails to be inserted, resulting in failure to stop the reactor, the boric acid injection pump 12 is automatically activated according to the logic of the shutdown signal and the power range neutron fluence rate signal. The high concentration of boron water in the two boric acid injection tanks 8 is injected into the core to introduce sufficient negative reactivity to achieve shutdown. If one of the boric acid injection units 15 fails, the isolation crucible 17 on the communication line 18 can be opened, and the high-concentration boric acid solution is injected into the cold-circuit section 501 of the three loops of the primary loop system by the intact boric acid injection unit 15 to realize the shutdown function. .

Claims

& He J wants

1. A high-pressure safety injection system for a nuclear power plant, which is configured on several loops of the reactor primary loop system, and is characterized by: including at least one boric acid injection unit and at least one coolant injection unit;

The boric acid injection unit includes a concentrated boric acid injection box, a concentrated boric acid injection pipeline with one end connected to the concentrated boric acid injection tank, and the other end of the concentrated boric acid injection pipeline penetrates into the containment vessel and is connected to one of the reactor primary loop systems. The cold pipe section of the loop;

The coolant injection unit includes a water source and a coolant injection pipeline connected to the water source; the coolant injection pipeline includes a parallel cold pipe section injection pipeline and a hot pipe section injection pipeline; the cold pipe section injection pipe The pipeline penetrates into the containment vessel and is connected to a cold pipe section of a loop of the reactor primary loop system; the hot pipe section injection pipeline penetrates into the containment vessel and is connected to a hot pipe section of a loop of the reactor primary loop system.

2. The high-pressure safety injection system according to claim 1, characterized in that: the water source can be a refueling water tank in the containment vessel.

3. The high-pressure safety injection system according to claim 1, characterized in that: a boric acid injection pump is provided on the concentrated boric acid injection pipeline; a high-pressure safety injection pump is provided on the coolant injection pipeline.

4. The high-pressure safety injection system according to claim 1, characterized in that: the reactor primary loop system includes three loops.

5. The high-pressure safety injection system according to claim 4, characterized in that: the three loops are configured with four coolant injection units, wherein two coolant injection units are independently connected to three of the reactor The first and second loops in the loop; the cold pipe section injection pipelines of the other two coolant injection units are also connected to the cold pipe section injection pipelines on the third loop among the three loops of the reactor. Pipe sections, the hot pipe section injection pipelines of the other two coolant injection units are also connected to the heat pipe section on the third of the three loops of the reactor.

6. The high-pressure safety injection system according to claim 4, characterized in that: the three loops of the reactor are equipped with two boric acid injection units, and the cold pipe sections of the three loops are connected through a mother pipe; The concentrated boric acid injection pipelines of the two boric acid injection units are connected to the mother pipe; the concentrated boric acid injection pipelines of the two boric acid injection units are connected through a connecting pipeline, and an isolation valve is provided on the connecting pipeline. .