DE1137810B - Heat absorption device for nuclear reactors for propulsion of ships - Google Patents

Description

GERMAN

PATENT OFFICE

C19581Vinc / 21g

REGISTRATION DAYS AUGUST 10, 1959

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL: OCTOBER 11, 1962

The invention relates to a heat absorption device for a nuclear reactor with liquid in the reactor core evaporating coolant, the steam of which is fed to a heat exchanger or turbine, and with an annular water-filled protective container surrounding the reactor.

The device for absorbing the heat should on the one hand when switching off the power or when Shutting down the reactor will take effect, regardless of whether it is a normal shutdown or an emergency shutdown in the event of a fault or an accident, and it should on the other hand prevent any overpressure that may occur in the primary circuit of the reactor, and thus at the same time reduce the risk of the safety valves in this circuit opening.

The present device, which is essentially a cooling device, is primarily for nuclear reactors useful, which are built into ships to provide heat to power the ship's turbines produce.

During a normal shutdown, the ship's turbo-generators - at least one of let them run for some time to absorb the heat that has already been generated in the reactor dissipate this way. You can also use other machine equipment of the The ship.

So if normal stopping doesn't pose difficult-to-solve tasks, it is completely different in the case of an emergency shutdown; especially if any malfunction occurs, such as an unforeseen one sudden closing of the valves of the turbine (or turbines), a leak on the Heat exchanger or an electrical fault.

In the event of an emergency shutdown, the energy that is required to keep the cooling circuit running and is generally very low, from special auxiliary equipment or from an accumulator battery to be delivered.

Emergency cooling systems for nuclear reactors are already known. However, these cooling systems have significant Disadvantages and are not readily suitable for operation in ships.

In one of the known cooling systems, changes in performance are made by moving the control rods of the reactor after the pressure display of the primary system allows, so that the pressure is reasonable remains constant. This control option is intended for normal power and pressure fluctuations. If the turbine is suddenly relieved of pressure, a second control circuit is activated. In this case, the Heat absorption device

for nuclear reactors for propulsion of ships

Applicant: Commissariat a l'Energie Atomique, Paris

Representative: Dipl.-Ing. R. Beetz, patent attorney, Munich 22, Steinsdorfstr. 10

Claimed priority: France of August 14, 1958 (No. 772 524)

Pierre Jean Ricard, Paris, has been named as the inventor

Nuclear reactor generated steam delivered to the condenser. Finally, there is a third control option insofar as the bunker rooms are lined with cooling pipe registers, which in certain operating states take action. This three-part control system has when used on ships serious drawbacks. Obviously there has to be a rapid change in the turbine power be made possible. The regulation of the immersion depth of the control rods can, however, only take place slowly because otherwise the operating state of the reactor could become unstable. Therefore need for flawless Adaptation to the turbine power at least two control options are used, which is a complicated one Tax system requires. To dissipate the cooling heat when the reactor is shut down, you must Finally, the cooling pipe registers in the bunker rooms are charged with cooling liquid.

In another known system, a special emergency cooling device is provided as a The cooling circuit is separated from the operating medium circuit and connected to it by a heat exchanger is trained. However, due to the spatial separation of the reactor and emergency cooling circuit, there are long pipelines required, which increase the susceptibility to failure. In addition, the safety cooler is shunted connected to the heat exchanger, and the function of the emergency cooling system depends on the function of the helium pumps, which are in the operating

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circle of the reactor. If the helium pumps fail, the entire system is therefore at risk.

The present device is based on the task of providing a heat absorption device (cooling system) to create for nuclear reactors that is simply constructed, can be regulated quickly and is operationally reliable is working.

This goal is achieved essentially in that in a reactor of the aforementioned Gatzur Level 2 height is available. The water vapor is drawn from the upper part of the vessel via a line 3 discharged, which opens into a (not shown) heat exchanger.

The steam condensed in the heat exchanger is fed into the vessel 1 as water via a line 4 returned, which is connected to the vessel at the lowest point marked 5. The condensation then enters the active reac-

the ring-shaped, water-filled protective container ίο gate cells via control devices.
According to the invention, a first water-flowing through it. Around the reactor vessel 1 is a protective container 6

Has cooling pipe system and a cooling pipe system, arranged, which the biological, d. H. the beam instead Inlet distributor to the feed line for warning protection. This tank is with pure exchanger or filled to the turbine and its effluent fresh water and contains several layers line for returning the condensed cooling 15 metal plates 7 (Fig. 2).

means is connected to the reactor vessel, so that in order to dissipate the heat that is generated during normal

the cooling circuit formed in this way, the heat exchanger or reactor operation in the radiation protection container 6 the turbine bridged, and that to control the forms, is a sea water circulation through a pipe flow of the tube system coming out of the reactor bundle 8 is provided, the steam through this second cooling tube system is little- 20 completely surrounded by the pure water. the at least one valve is provided. Use of sea water as a cooling liquid is

With such a design of a heat dissipation device, it is in no way mandatory and not a feature of the absorption device the circulation becomes through sensation; For this purpose it can also be used in any way maintained without using any of their coolants. The tube bundle 8 Pumps are required. All operating states 25 are between two annular feed manifolds 9 and of the reactor, which during operation on ships he discharge manifolds 10 are arranged. The sea water or another coolant circulates in the tubes of tube bundle 8 in the direction of arrows 11. The circulation of the sea water in the tube bundle 8 30 can be carried out by means of a pump which is arranged in the liquid circuit of the pipes 12 to which the circular inlet manifolds 9 and drain collector 10 are connected. The outflow from the collectors 10 takes place through Siphonwir-35 effect, so that the pressure in the tubes of the tube bundle 8 is below that prevailing in the container 6

can give can be mastered in a simple and safe manner, with the automatic control device is particularly simple in structure since it only has to operate a single control circuit.

The valve for controlling the flow of the steam coming out of the reactor is preferred arranged between the feed line of the heat exchanger or the turbine and the second cooling pipe system.

Furthermore, a second one, see opening in the event of excess pressure, can be used Valve between the feed line of the heat exchanger or the turbine and the second cooling pipe system be switched.

Preferably there are in the annular container between the first and second cooling pipe systems Partition walls arranged, which have passages at their lower and upper regions.

To cool the reactor when removing or changing the fuel elements, it can be advantageous use a reactor coolant circulation pump connected to the reactor vessel and the coolant conveys into the second cooling pipe system, which is connected to the one at the bottom via an additional valve Pressure and in the event of leaks the seawater will not enter this container can.

The radiation protective container 6, which contains the tube bundle 8 fed with seawater, is used in order to remove the residual heat from the reactor, which in the event of a shutdown would still be in the Reactor is contained or is still to be released.

For this purpose, a second system or bundle of pipes 13 is also in the pure water of the Container 6 arranged; the tubes of this bundle are located between an inlet manifold 14 and an outflow collector 15 in a cycle that on the one hand

Part of the reactor vessel lying inlet for the 50 via a line 16 to the line 3 of the heat

Condenser water of the heat exchanger is connected.

The invention is described on the basis of schematic drawings using an exemplary embodiment. It shows

Fig. 1 is a schematic representation of a reactor with a device according to the invention to absorb the heat in the event of a power shutdown or shutdown of the reactor is,

Fig. 2 is a larger-scale sectional view of a device according to the invention, shows the details of the protective container and the two pipe systems arranged in the container are.

In Fig. 1 the nuclear reactor is in a liquid pressure vessel 1, which contains a liquid, e.g. water, which is contained in the outer reflector to exchanger circuit or the turbine and on the other hand via erne line 17 or 18 to the vessel 1 of the reactor connected. The tasks of the lines 17 and 18 are explained in more detail below.

The line 16 contains two valves 19 and 20, which are connected in parallel to one another, where appropriate a single valve could also perform the tasks of the two valves 19 and 20. The valve 19 is provided with means for its control by special organs, while the valve 20 opens automatically at an adjustable overpressure in line 3.

The line 17 contains a valve 21 which is provided with means for controlling its opening.

A valve 22, which is a valve of the same type as the valve 21, is also located in the line 18.

In the container 6 partitions 23 are provided,

which subdivide the interior of the vessel and with

lower (inlet openings 24) and upper (outlet openings 25) passages are provided. These partitions ensure a natural circulation of the Fresh water in the container 6, namely between the spaces of the two tube bundles 8 and 13.

This arrangement, as just described, works in the following way:

When switching off the power or shutting down the reactor, the valves 19 and 21 are opened to to short-circuit or bridge the heat exchanger via the pipe system or bundle 13. In the Incidentally, in practice, valve 21 always remains open, as will be explained in more detail below. A natural circulation then forms via the line 3, the valve 19, the line 16, the pipes of the tube bundle 13, the line 17 and a line 26 which leads into the reflector chamber of the reactor. The tube bundle 13 then plays the role of a condenser.

On the other hand, even if the valve 19 is kept closed at will, the circulation can be introduced into the tube bundle 13 thanks to the action of the automatically opening valve 20. For example, this valve can be set to a pressure 10% above normal Pressure lies. As a result, this valve 20 also reduces in the event of unintentional setting larger pressure fluctuations in the steam line 3 the risk of undesired opening of the actual overpressure protection valves 27, which are only available at a much higher excess pressure should open.

In order to ensure the operation in the sense just described, the valve 21 must be at normal Operation to be left open; this does not result in any disadvantage, since the tube bundle 13, which is in the cold Water of the container 6 is arranged, then also acts as a condenser at overpressure.

The device is completed by a circulation pump 28, which is connected to a line 26 in a Line 29 on the one hand and via a pipe 30 and a controllable valve 31 to the line 16 on the other hand is switched on. This additional arrangement of a circulation pump 28 allows Cooling of the reactor during the work involved in removing or replacing the in the reactor sedentary fuel elements must be carried out, d. H. when the lid of the reactor is removed and the reactor vessel is filled with water. In this case, the protective container 6 is also used for cooling used; however, no natural circulation occurs in the tube bundle 13, and the circulation becomes at closed valve 21 and open valve 22 forced by the circulation pump 28.

The circulation pump 28 causes the reactor water to circulate via line 26 until it is reintroduced at point 5 (in Figs. 1 and 2) at the bottom of the vessel 1. The water runs through the line 26, the line 29, the pump 28, the line 30, the valve 31, the tube bundle 13, the Line 18, the valve 22 and that part of the line 4, which at point 5 in the reactor vessel flows out.

The device just described allows the absorption of the heat that, in the case of a Shutdown or shutdown of the reactor is still given, even if it is a sudden Stopping in an emergency or a stopping made to remove the fuel elements will. The device also allows the automatic inclusion of part of the Reactor generated heat in those cases where overpressure occurs. This can also the greatness of this overpressure are limited.

Claims (5)

PATENT CLAIMS: 1. Heat absorption device for a nuclear reactor for propelling ships with liquid coolant evaporating in the reactor core, the vapor of which is fed to a heat exchanger or turbine and with an annular water-filled protective container surrounding the reactor, characterized in that this container has a first cooling pipe system through which seawater flows and a second cooling pipe system, the inlet manifold of which is connected to the feed line to the heat exchanger or to the turbine and whose outlet manifold is connected to the return of the condensed coolant to the reactor vessel, so that the cooling circuit thus formed bridges the heat exchanger or the turbine, and that to control the flow of the out steam coming to the reactor through this second cooling pipe system is provided at least one valve. 2. Device according to claim 1, characterized in that the valve between the feed line of the heat exchanger or the turbine and the second cooling pipe system. 3. Device according to claims 1 and 2, characterized in that a second, at Overpressure opening valve between the feed line of the heat exchanger or the turbine and the second cooling pipe system is connected. 4. Device according to one or more of claims 1 to 3, characterized in that in the annular container between the first cooling pipe system and the second partition walls are arranged which contain passages in their lower and upper parts. 5. Device according to one or more of claims 1 to 4, characterized in that a circulation pump to cool the reactor when removing or changing the fuel elements (28) is provided for the reactor coolant, which is connected to the reactor vessel and the coolant in the second cooling pipe system (13) promotes, which via an additional valve (22) with the inlet for the condensate water of the heat exchanger located at the lower part of the reactor vessel connected is. Documents considered: Atompraxis, Vol. 2, 1956, pp. 140 and 141; Atomics and Nuclear Energy, Vol. 9, 1958, pp. 156 and 157. 1 sheet of drawings © 20 »660/240 10.62