RU2243602C1 - Operating process of nuclear reactor cooling circuit - Google Patents

Abstract

FIELD: nuclear power engineering; cooling nuclear reactors.

SUBSTANCE: operating process of nuclear reactor cooling circuit includes coolant supply to inlet conduit and its discharge from outlet conduit in even number of parallel flows over pipelines to steam generators and then to main circulating pumps, as well as compensation and makeup of coolant volume; cooling circuit operating process also includes coolant supply to reactor in even number of opposing parallel flows by means of supply conduit divided into two parts by means of closed dampers and communicating flows of outlet coolant by means of crossbars with normally open dampers; coolant volume compensation and makeup is provided to one of discharge coolant sections distant from reactor.

EFFECT: enhanced safety in emergency situations involving breakdown of one of independent primary-circuit coolant supply pipelines.

1 cl, 1 dwg

Description

The invention relates to nuclear energy and can be used to cool nuclear reactors.

A known method of controlling a nuclear reactor [US Patent No. 4299657, G 21C 7/06, 1981] with water cooling, comprising the arrangement of the reactor core with control rods located therein, as well as the process of controlling the energy release field by changing the chemical or physical state of the coolant to achieve optimal energy release.

The disadvantage of this method is that a change in the chemical state can lead to damage and destruction of the coolant coolant circuit.

There is also known a method of operating a cooling circuit of a nuclear reactor [NPR Production Reactor in the USA. The journal “Nuclear Technology Abroad” No. 4, pp. 19-23], taken as a prototype, including the supply of the coolant to the supply line and the discharge of the waste coolant from the discharge line by an even number of parallel flows through the pipelines to the steam generators and then to the main circulation pumps, and also compensation, replenishment of the coolant volume.

The first disadvantage of this method is that the coolant is supplied to the reactor through supply pipelines through a closed supply communication connecting the coolant flows, which is then distributed to the group distributors of the coolant. In the event of an emergency rupture of one of the supply pipelines, the coolant rushes into the gap from two sides: from the direction of the coolant supply direction through the pipeline that has received a break, and from the opposite side from the non-emergency pipeline through the closed supply communication to the gap.

The second disadvantage of the prototype is that when one of the independent supply pipes ruptures, the water from the emergency reserve is supplied to the closed supply communication and then to the gap, not reaching the reactor core, which impairs heat dissipation from the fuel elements and can lead to their higher damage.

The third disadvantage of the prototype is that the pressure compensators are embedded directly into the closed communication of the heat transfer fluid, located directly at the outlet of the reactor. Therefore, in an accident with a rupture of one of the supply pipelines, a rarefaction wave passes quickly through the supply lines, through the reactor’s technological channels and then the pressure drop is constrained by the operation of pressure compensators, which prevents the emergency stock water from flowing into the technological channels and impairs the heat removal from the fuel elements.

The objective of the invention is to provide safer operation of the cooling circuit of a nuclear reactor in an emergency with a rupture of one of the independent pipelines for supplying the coolant of the first circulation circuit.

The problem is solved in that in the method of operating the cooling circuit of a nuclear reactor, which includes supplying the coolant to the inlet communication and the outlet of the outgoing coolant from the outgoing communication with an even number of parallel flows through the pipelines to the steam generators and then to the main circulation pumps, as well as compensation, replenishment of the coolant volume, operation of the cooling circuit is carried out in the mode of supply of the coolant to the reactor with an even number of countercurrent parallel flows by means of a divided into two parts by closed valves of the inlet communication and communicating flows of the waste coolant by means of jumpers with normally open shutters, while compensation and replenishment of the volume of coolant is provided in a section of one of the flows of the coolant remote from the reactor.

The essence of the method of operating the cooling circuit of a nuclear reactor is illustrated in the drawing.

During normal operation of the cooling circuit of a nuclear reactor, water is supplied to the reactor under pressure through independent supply pipelines 1 by an even number of countercurrent flows in parallel, through a feed communication 2 divided into two parts by closed valves 18, then to group distribution manifolds 3 through the technological channels 4 of the nuclear reactor with fuel elements, where the heat carrier is heated. Then, the coolant flows from the technological channels to the group collectors 5 for collecting the coolant, then the outgoing coolant is discharged from the outgoing communication 6 with an even number of parallel communicating outflows of the outgoing coolant through jumpers with normally open valves 19 through the outlets of the coolant 7 from the reactor. To compensate for changes in the volume of the coolant in the circulation circuit caused by changes in the temperature of the coolant due to changes in reactor power, compensation tanks 8 of the volume of the coolant in the circulation circuit are used, partially filled with water under gas pressure, which is held by the compressors 9. Recharge pumps are used to feed the coolant into the circulation circuit 10. The circulation of the coolant in the circuit is ensured by the operation of the main circulation pumps 11L and 11R. To perform the repair of the circulation circuit at a stopped reactor, valves 12, 18, 19 are used. The valves shown darkened are closed and, accordingly, the darkened valves are open. The check valves 13, as well as check valves 13R and 13L, which, if necessary, act as gate valves and check valves, are also installed in the circulation circuit. To remove heat from the coolant heated in the reactor, steam generators are used 14. Tanks for storing emergency water supply 15 are connected by pipelines 16 to the circulation circuit at the inlet to the main coolant circulation pumps 11L and 11R and have a water recharge system 17.

To eliminate the first two drawbacks of the prototype in the circulation circuit on the pipelines connecting the coolant supply pipelines to each other, and on the closed supply communication, valves 18 are installed that are closed during operation of the reactor at power, which, when the coolant supply pipe breaks in section A-A, provides water to the reactor via the second non-emergency water supply pipe to remove heat from the fuel rods. At the same time, water from the emergency reserve compensates for the loss of water in the gap and ensures the supply of the required amount of water to avoid exceeding the allowable limit of damage to the fuel rods; for this, the emergency supply of water is supplied to each coolant supply pipe through check valves 13C. To reduce the loss of coolant from the circulation circuit to the gap A-A, the main circulation pumps 11R, which supply the coolant to the reactor through the emergency pipeline, are turned off and cut off with valves. For repairs, the reactor is stopped, the repaired pipelines and the equipment of the circulation circuit are cut off by closing the gate valves 12R, 19, closing the gate valves 13R and then empty through the drains, while the coolant flow through the reactor and the fuel elements are cooled through other independent coolant supply and removal pipelines.

To eliminate the third drawback of the prototype valves 19, connecting the pipelines for the removal of coolant from the reactor, are open, while the compensation and replenishment of the volume of the coolant is carried out in one of the outlet pipelines 7. In contrast to the prototype, compensation and recharge of the volume of the coolant only partially inhibit the pressure drop in the primary circuit after rupture and do not interfere with the supply of water to the reactor from a non-emergency pipeline. In addition, due to the large length of the pipelines, the location of the insert in the compensation pipe and replenishing the coolant volume far from the reactor allows longer than in the prototype to move along the contour of the rarefaction wave, which ensures unhindered water supply to the reactor from the non-emergency pipeline.

Thus, the cooling and operation of the cooling circuit of a nuclear reactor in an emergency is ensured.

Claims (1)

A method of operating a cooling circuit of a nuclear reactor, comprising supplying a coolant to the inlet communication and withdrawing the outgoing coolant from the outgoing communication with an even number of parallel flows through the pipelines to the steam generators and then to the main circulation pumps, as well as compensation, replenishment of the coolant volume, characterized in that the operation of the cooling circuit carried out in the mode of supply of the coolant to the reactor with an even number of counter parallel flows by means of a closed in two parts inlet valves bubbled communication and communicating exhaust coolant flows through the jumper with normally open valves, and the volume compensation and makeup coolant is provided in the portion remote from the reactor of one of the exhaust coolant flows.