RU64424U1 - MONOBLOCK NUCLEAR REACTOR PLANT WITH LIQUID METAL FUEL-HEAT CARRIER - Google Patents

Abstract

The utility model relates to nuclear energy, and more narrowly to nuclear reactor installations (NRU) with fuel and coolant in the form of melts and water as the working fluid of a steam turbine installation.

The proposed monoblock nuclear reactor consists of a block of structures and devices of the first circuit 2, a block of structures and devices of the intermediate circuit 3 and includes: an active zone of a fast neutron reactor; first and intermediate circuits; a heat exchanger of the first - intermediate circuits 4, combined with the reactor core; intermediate circuit heat exchanger - a steam generator integrated in the neutron reflector cavity; a channel (channels) of a fuel melt stirrer, built-in (built-in) in the reactor core, through which an inert gas is pumped using a gas blower connected to an inert gas purification device.

The developed utility model is characterized in that the primary coolant is a suspension of thorium oxides and fissile materials in a lead melt, and the lead melt is a coolant of the intermediate circuit; the heat exchanger of the first - intermediate circuits, combined with the reactor core is a system of lowering fuel channels 5 of the primary fuel coolant melt and lifting channels 6 stirring agents for mixing the fuel coolant melt, bounded above the tube plate by the cylinder bottom of the cyclone type melt separation device of the primary circuit and gases, and from below the tube plate - the cylinder cover of the primary melt collector of the primary circuit; the inducers of pumping and mixing the suspension of the molten fuel-coolant are the jet devices located in the lower part of the lifting channels 6 of the coolant-fuel, and in the upper part of the nozzle 10.

Description

The utility model relates to nuclear energy, and more narrowly to nuclear reactor installations (NRU) with fuel and coolant in the form of melts and water as the working fluid of a steam turbine installation. Nuclear reactors with liquid salt reactors (LSR) are known in which melts of the salt composition of fluorides are the fuel and coolant.

The closest in technical essence and the achieved result is a monoblock nuclear power reactor with a liquid salt reactor [“Nuclear reactor installation with a coolant fuel in the form of fluoride salt melts”, Yakovlev PM, Kuzyakin Yu.I., Utility Model Patent No. 57040 dated September 27, 2006] .

Nuclear fuel reactor with fuel and coolant in the form of fluoride salt melts, includes thermal neutron-containing liquid ferrous metals, primary and intermediate circuits, a primary – intermediate circuit heat exchanger, pipelines and an intermediate circuit circulation pump, a steam generator pipe system, tanks for draining fluoride molten salts of the first and intermediate circuits, and A device for purifying a molten fluoride salt of nuclear reaction products. Wherein:

- structurally, the nuclear switchgear is made monoblock, in which the first and intermediate circuits and the heat exchanger of the intermediate circuit — the steam generator are located directly in the ZhSR block;

- the intermediate circuit is made in the form of channels in graphite blocks - a moderator of the reactor core and cavity in the neutron reflector block;

- the heat exchanger of the first - intermediate circuits is made in the form of channels built into the blocks of graphite - the neutron moderator of the reactor core;

- the heat exchanger of the intermediate circuit - the steam generator is made in the form of a cavity located in the block of graphite neutron reflector;

- the tube system of the steam generator is built into the cavity of the intermediate circuit located in the blocks of graphite neutron reflector;

- in the active zone of the ZhSR a channel is built in to stimulate the mixing of the molten fuel salts, through which an inert gas is passed through gas blowing;

- the channel for stimulating the mixing of the molten salt of the fuel is connected to a device for purifying the inert gas from the gaseous and volatile products of nuclear reactions contained therein.

The disadvantages of this installation include:

- high chemical activity of fluoride melts in the core and the intermediate circuit to all structural materials, except graphite;

- high relative carbon content (about 90%) in the form of graphite blocks (channels) in the reactor core, not able to withstand high radiation loads due to the appearance of cracks in them and requiring periodic replacement;

- the presence in the reactor core of light elements (lithium and beryllium salt composition of melts and carbon graphite blocks) makes the reactor thermal, depending on the accumulation of fission products with a large capture cross section of thermal neutrons;

- the fuel circulation stimulator located in the central part of the reactor core provides only sluggish circulation and mixing of the melt inside the core, which leads to an inhomogeneity of the temperature field inside the core and makes it difficult to remove slag (fission products) from the fuel melt.

The objective of the proposed utility model is the development of a monoblock nuclear reactor installation with liquid fuel-coolant less chemically active, more efficient, economical by increasing its operating time without replacing structural elements.

The technical result of the proposed utility model is: a 5-7-fold reduction in the volume of the reactor core due to the exclusion of lithium and beryllium salt composition of melts and graphite blocks from the reactor core, which significantly reduces the size of the nuclear reactor and its cost, as well as increasing the efficiency of the use of nuclear reactor due to eliminating the need for periodic replacement of structural elements from graphite and reducing the amount of solid radioactive waste. A monoblock nuclear reactor with liquid fuel-coolant includes the reactor core, the first and intermediate circuits, the heat exchanger of the first - intermediate circuit, the heat exchanger of the intermediate circuit - a steam generator, and the channel for stimulating the mixing of the fuel melt by passing inert gas through it. The primary coolant coolant is a suspension of thorium oxides and fissile materials in the lead melt, the lead coolant is the lead melt, the first – intermediate circuit heat exchanger combined with the reactor core is a system of lower heat-generating channels of the primary coolant fuel-melt and lift channels stimulants for mixing the coolant fuel melt, bounded above by the tube plate of the cylinder of the first melt separation device round and gases, and from below the tube plate of the cylinder of the primary collector of the melt of the primary circuit,

The inducers of pumping and mixing the suspension of the fuel-coolant melt are the jet devices located in the lower part of the lifting channels of the fuel-coolant, and in their upper part are nozzles.

The proposed monoblock nuclear reactor consists of a block of structures and devices of the primary circuit, a block of structures and devices of the intermediate circuit, and includes:

- the active zone of a fast neutron reactor;

- first and intermediate circuits;

- heat exchanger of the first - intermediate circuits, combined with the reactor core;

- heat exchanger of the intermediate circuit - a steam generator built into the cavity of the neutron reflector;

- channel (s) of the fuel melt stirrer, built-in (built-in) in the reactor core, through which inert gas is pumped using a gas blower connected to an inert gas purification device.

The developed utility model is characterized in that:

- the primary coolant coolant is a suspension of thorium oxides and fissile materials in the lead melt, and the lead melt is the lead coolant;

- the heat exchanger of the first - intermediate circuits, combined with the reactor core, is a system of lowering heat-generating channels of the primary fuel coolant melt and the lifting channels of the fuel-coolant melt stirring channels, bounded from above by the tube plate - the cylinder bottom of the cyclone-type device for separating the primary circuit melt and gases and from the bottom with a tube plate - the cylinder cover of the primary melt collector of the primary circuit;

- the impulses for pumping and mixing the suspension of the fuel-coolant melt are the jet devices located in the lower part of the lifting channels of the fuel-coolant, and in the upper part of the nozzle.

The block of structures and devices of the primary circuit is the active zone of a fast reactor, combined with the heat exchanger of the primary - intermediate circuits, and includes: molten liquid metal fuel-coolant of the primary circuit, lowering fuel channels, lifting channels for gas initiation of circulation and mixing of the fuel-coolant, prefabricated collector and fuel circulation pumps -

coolant. An intermediate circuit coolant circulates in the interchannel space of the block.

The block of structures and devices of the intermediate circuit is the supporting structure of the monoblock of the nuclear reactor, consists of graphite blocks of the neutron reflector and includes: molten liquid metal coolant, a central cavity to accommodate the block of structures and devices of the primary circuit, peripheral cavities to accommodate the pipe system of the integrated steam generator and circulation pumps of the melt liquid metal coolant.

Figure 1 shows the proposed monoblock nuclear reactor, including:

1 Monoblock of a nuclear reactor with a fast neutron reactor, consisting of a block of structures and devices of the primary circuit and a block of structures and devices of the intermediate circuit.

2 Block designs and devices of the primary circuit.

3 Block structures and devices of the intermediate circuit.

4 The reactor core, combined with the heat exchanger of the first - intermediate circuits.

5 Lowering the fuel channels of the melt of the primary circuit.

6 Lifting channels of the melt of the primary circuit.

7 Inkjet devices for gas initiation of circulation and mixing of the primary circuit melt.

8 The cylinder of the prefabricated collector of the melt of the primary circuit.

9 Device for the separation of gas and molten primary circuit.

10 Nozzles of ejection of a two-phase mixture of gas and melt tangentially to the generatrix wall of the cylinder of the gas and melt separation device of the primary circuit.

11 Auxiliary primary melt circulation pumps.

12 The heat exchanger of the intermediate circuit - the steam generator with its pipe system.

13 Circulation pumps melt intermediate circuit.

14 Tank for draining the melt of the intermediate circuit.

15 Tank for draining the melt of the primary circuit.

16 Device for purification of inert gas from gaseous and volatile products of nuclear reactions.

17 Gas blower.

The inventive YAR operates as follows.

The functioning of the block of structures and devices of the first circuit of the nuclear reactor is as follows.

A nuclear reactor runs on fast neutrons due to the absence of a moderator (graphite and other light elements) in its core. The reproduction coefficient of the fissile isotope of uranium-233 from thorium-232 in the fuel is at least 1 and does not decrease during the reactor campaign.

The heat released during fission of uranium-233 nuclei heats the fuel-heat carrier of the primary circuit, which is used as a suspension of thorium-232 oxides and the fissile uranium-233 isotope in a lead melt. Due to the almost identical (difference within 5%) density of oxides with molten lead and continuous mixing, they are uniformly placed in the entire volume of the coolant fuel. The hot melt of the heat-transfer fluid transfers heat to the melt of the coolant of the intermediate circuit circulating in the inter-channel space of the core — the heat exchanger of the first and intermediate circuits 4.

The circulation of the melt along the primary circuit and continuous intensive mixing of all components of the suspension is ensured by the operation of special inkjet devices 7 that produce a homogeneous two-phase flow of a suspension of fuel-coolant and inert gas in the lifting channels 6.

At the exit from the channels 6, a homogeneous two-phase flow of a suspension of fuel-coolant and inert gas at a speed of several meters per second is ejected through nozzles 10 tangentially to the cylinder generatrix of device 9. The intensive rotation of the two-phase flow ensures its effective separation into liquid and gas fractions due to centrifugal forces . The separation of inert gas and the continuous removal of all gaseous and volatile gases along with it, as well as separation during centrifugation of the melt and subsequent removal of most other fission products (so-called slag) with a density significantly lower than the density of the lead melt, provides insignificant changes in the initial composition of the primary melt even during continuous operation of the reactor.

The melt of the primary circuit by auxiliary circulation pumps 11, which operate only when starting and stopping the reactor, is fed into the lifting channels 6 to ensure circulation and centrifugation of the heat-transfer fluid.

Inert gas, which is an active working fluid in jet devices 7, is continuously cleaned of gaseous and volatile products of nuclear reactions in device 16 and gas blower 17 is again fed to the inputs of inkjet devices 7.

The functioning of the block structures and devices of the intermediate circuit of the nuclear reactor is as follows.

The liquid metal coolant of the intermediate circuit (lead melt) with its circulation pumps 13 is pumped through the central cavity with the block of structures and devices of the first circuit located in it, is heated in the interchannel space of the core — the heat exchanger of the first and intermediate circuits 4, cooling the melt of the primary circuit, and then enters peripheral cavities of the block, where it gives off heat to the pipe system 12 of the steam generator.

The main positive results of the developed utility model of nuclear weapons are as follows:

- In the proposed fast neutron reactor with a liquid metal fuel-coolant and with a reproduction coefficient of the fissile isotope of at least 1, there is no problem of fuel poisoning by fission products with large capture cross sections of thermal and resonant neutrons.

- The use of thorium-232 and uranium-233 oxides as a suspension in a lead melt with continuous intensive mixing of the melt allowed us to return to the developed technologies of liquid metal coolants and to obtain nuclear power plants with an almost unlimited campaign of fuel reserves.

- To ensure the necessary duration of the reactor campaign, only timely replenishment of thorium-232 oxide is necessary, which does not pose a serious problem even when the reactor is operating at energy power levels and does not require large financial costs due to the low cost of the initial fuel - thorium-232 oxide.

- Continuous cleaning of the fuel-coolant melt from gaseous, volatile and other harmful decay products of fissile material nuclei allows maintaining the initial fractional composition of the fuel suspension in the lead melt throughout the reactor campaign.

- Reducing the volume of the reactor core by 5-7 times significantly reduces the size of the nuclear reactor as a whole and its cost, increases the efficiency of the use of nuclear reactor and reduces the amount of accumulated solid radioactive waste.

Claims (1)

Monoblock nuclear reactor installation with liquid metal fuel-coolant, including the reactor core, the first and intermediate circuits, the heat exchanger of the first - intermediate circuit, the heat exchanger of the intermediate circuit - a steam generator, a channel for stimulating the mixing of the fuel melt by passing inert gas through it, characterized in that The primary circuit coolant is a suspension of thorium oxides and fissile materials in a lead melt, and the intermediate circuit coolant is lead is molten, the heat exchanger of the first and intermediate circuits, combined with the reactor core, is a system of lowering heat-releasing channels of the primary fuel-coolant melt and lifting channels of mixing agents for mixing the fuel-coolant melt, bounded above by the tube plate of the cylinder of the device for separating the primary melt and gases and from below the tube plate of the cylinder of the primary collector of the melt of the primary circuit, the drivers of pumping and mixing the suspension of the molten fuel- eplonositelya are located at the bottom of the lifting channel fuel-coolant jet device, and in their upper part, the nozzle.