DE2327756A1 - SAFETY DEVICE WITH LIQUID ABSORBER FOR NUCLEAR REACTORS - Google Patents

Description

Safety device with liquid absorber for nuclear reactors.

The invention relates to a safety device that dasu determines 1st, the reactivity of a nuclear reactor by very rapid introduction of an absorbent liquid into a volume located in the reactor core lower.

The devices to shut down the reactor Introducing a liquid absorber provide the gate part compared to the usual devices such as rule tables, that they themselves in the event of an explosion or one serious accident can work in the reactor.

Among the devices for stopping by means of an absorber « some work by directly inserting the Absorbers in the coolant or in the moderator.

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So Han has a lot of trouble getting to this extract; the separation instaxation for the absorber is 1st very space-consuming and extremely complicated.

In other devices, the absorber circulates la pipes which pass through the reactor in places; the The absorber is kept in a ready-to-use state outside the reactor core with the aid of a gas pressure; the absorber reserve is outside the reactor in a gas » pressurized canisters stored. TIe the absorber hurling bu into the tubes penetrating the reactor core, it is sufficient either to plot the teedruok in the canister bu raise or decrease the pressure bu holding the absorber outside the core.

These devices indicate the braid * uf, & a £ si ·, ^ m In Must be operated from outside. On the other hand, the liquid filled a Rehrl ·! « tations are relatively long, which is accompanied by losses and inertia when the fluids are set in motion mud, which is detrimental to rapid response and requires considerable pressure. In addition, these fz & ghe £ t «a practice an unfavorable effect on boys; (Stoi) diapfer must be arranged in order to avoid the fluidsul © ahsu «» brake.

In order to remedy these disadvantages, a safety device with absorber liquid is to be proposed, whose triggering takes place automatically and which only dl · liquid ·? amount corresponding to a column of the same height as required by the core, which makes it possible, due to the low inertia of this column, to dispose of the liquid quickly

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push and shut down without the complicated braking system.

The safety device with liquid absorber for nuclear reactors according to the invention is characterized by a cylindrical vertical reservoir with two connected collectors arranged one above the other, the upper chamber with liquid absorber, above which a Gt ** under Druok P ^ is stored, filled and the lower chamber located in the reactor core with gas under a pressure? £ »which is slightly greater than P ₁ and is provided with a connection to the outside, which ends by a closing organ in the reactor core and its tightness of depends on the working conditions of the reactor.

If the reactor works badly C breakdown in the cooling circuit, explosion ...) »so the SehlieSorgaa is partially κerstrict and the lower chamber is suddenly relieved of pressure, so that the liquid absorber in the lower chamber under the influence of the pressure _? which is still in the upper chamber herrsoht ₉ driven out.

The choice of the closing element depends on the parameter that you have wishes to monitor in the reactor. A first one Embodiment one uses a fusible uranium pastille or «such a uranium platelet, which against The neutron flow is sensitive and over its circumference with " Is soldered using a fusible metal.

3 According to a wide design for gas-cooled actuators a pressure sensitive membrane is used.

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Preferably the one ending with the closing member penetrates Connection naoh the invention the lower wall of the lower Chamber and is extended towards the interior of the lower chamber by a vertical tube, the upper end of which is calibrated in the Near the head of the lower chamber

If thus absorber liquid in the lower chamber naoh was driven out with a brush in the tightness of the closing element, it remains in this chamber. catch. The vertical pipe prevents the liquid absorber from escaping through a connection that is then open and to spread in the reactor core.

An example embodiment of the invention is intended will now be explained in more detail with reference to the accompanying single drawing.

The safety device shown consists of a vertical cylindrical reservoir 1, soft approximately in its center through a partition 2 into an upper chamber 3 and a lower chamber 4 is divided.

The lower chamber 4 has a height which is slightly greater than that of the reactor core, in which it is located is _f. The upper chamber 3 is thus arranged above the reactor core.

The chambers are connected to one another via a ring line 5 » which is tangent to the inner walls of the memory 1, in connection and which starts from the base of the lower chamber 4 and in the upper chamber 3 at the level of the partition 2 via © ine Siphonelnrioiatung 6 opens «

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The lower chamber 4 let with a vertical pipe 7 " coaxially with the memory 1, the upper end of which is located adjacent to the partition 2 and the lower end of which opens outside the Spelohers 1 and is closed by a sole organ 8, which consists of a uranium pastille or a uranium plate, which is attached to its circumference with the help of a certain temperature melting metals soldered 1st * Above the reservoir or spreader 1 there is a closed space 9 of small volume, which is provided with a valve 10 and a closable opening 11 Im upper part provided 1st. This closed space 9 is vertical with the lower chamber 4 Pipeline 12 in connection, which is hesüglioh the axis of the reservoir 1 versetst and the upper chamber 3 duroh -setet.

The reservoir is advantageous in a bushing, not shown, which is the same as that for the fissile material or Fuel used is arranged.

The operation of the safety device according to the invention is as follows

Since the reservoir is 1 sioh outside the reactor, you pour liquid absorber, for example lithium duroh the opening 11 until the liquid in the lower chamber 4 reaches below the upper part of the vertical tube 7. The opening 11 is then closed or sealed.

The reservoir 1 is pressurized by adding gas,

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for example argon or helium, introduces via the valve 10, so that the liquid via the ring line 5 rises to the upper chamber 3. If the entire Liquid has entered the upper chamber 3 and the gas pressure in the lower chamber 4 is clearly higher is the pressure prevailing in the reactor core, it is opened the gas supply and the valve 10 close; one can then sealed the outlet opening.

The gas in the upper chamber then has a bracket P ₁ which is slightly smaller than the Dmok Pg in the lower chamber; the pressure differential Pg - P ₁ is equal to the pressure exerted by the column of liquid.

The reservoir is then placed in a sleeve (not shown) in the reactor core containing the fuel. In fact, only the lower chamber la core is arranged; the upper chamber is located above the core.

Ia case of rapid Äiaktorea becomes the reservoir of a coolant, for example liquid »Katrins, washed around.

If the uranium plate is a nonaline Heutronflui is exposed, it remains at a temperature below the melting point of the LBtmittel and the liquid The absorber remains in the upper chamber 3 above the reactor core.

If the reactor looks through, the Heutroneafluf becomes prohlbitiv and the plate 8 is warmed up; the solder aehmllit *

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The platelet is then under the influence of pressure of the gas in the lower chamber 4 is expelled. Ss then creates a negative pressure in the lower Chamber 4 and the liquid absorber is in this Chamber thrown under the influence of the pneumatic relaxation of the gas contained in the upper chamber 3. The liquid absorber finds its balance under the upper end of the vertical tube 7 and remains trapped in the lower chamber.

The safety device according to the invention acts in certain catfish like a fuse »which is practical instantly causes a drop in the reactivity of the reactor.

It is clear that even in the event of an explosion leading to mechanical deformation of the core, the liquid absorber can descend into the lower chamber 4.

The triggering of the door direction is extremely safe, since neither an actuation from the outside nor the use an energy source outside the reactor is required.

In the case of gas-cooled reactors, the uranium plate can be used Replace with a pressure-sensitive membrane for certain safety devices.

The reservoirs provided with membranes are in the Reactor core lowered without being pressurized would and without the valve 10 needing to close.

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If the gas-cooled reactor is filled, it turns out a pressure equal to that prevailing in the factor lower chamber 4 via the valve 10 and the liquid absorber is driven into the upper chamber 3.

The membrane is sensitive to any negative pressure in the reactor and, as soon as a negative pressure is established, which exceeds a predetermined value, so bursts the membrane; das (ias from the lower chamber 4 escapes and the liquid absorber is thrown into this chamber.

Although the safety device just described which is the most advantageous for implementing the invention, of course, know a wide variety of modifications within the scope of the invention; Certain of the elements can be replaced by other elements that are able to perform the same function ode? to fulfill an equivalent technical function, be replaced

Expectations; 309881/0367 _Q

Claims (8)

Expectations 1 *) Safety device old liquid · «Absorber for nuclear reactors, characterized by a rertikalee cylindrical reservoir (1) with swel connected channels (4» 3) arranged one above the other, whereby the upper chamber (3) in the reactor is arranged above the core and with a liquid absorber is filled, above which a gas is stored _{under a pressure P 1;} that the lower chamber (4), which is located in the reactor core, is _{filled with gas at a pressure P 2} , which is slightly greater than P ₁ lit, with a connection to the outside which is in a closing element (8) ends which si oh is in the reactor core and its tightness depends on the operating conditions of the reactor * 2. Safety device according to claim 1, daduroh characterized in that the connection ending through the sole measuring element (8) extends the lower wall of the lower chamber (4) penetrated and extended against the inside of the lower chamber via a vertical tube (7), whose upper end is adjacent to the top of the lower Chamber (4) is located. 3. Safety device with liquid absorber after one of claims 1 or 2, characterized in that the invert organ consists of a uranium plate (6), which is soldered on its circumference by means of a meltable metal. 4. Safety device with liquid absorber after one of claims 1 or 2, characterized in that the closing organ is a pressure-sensitive membrane. 30 98 81/0367 - ίο - 5. Safety device with liquid absorber according to one of the preceding claims, characterized in that the reservoir (l) also has a valve (10) for introducing gas into the lower chamber (4). 6. Safety device with liquid absorber according to one of the preceding claims, characterized in that the two chambers (3 »4) of the reservoir (1) are connected via a ring line (5) which starts from the base of the lower chamber (4) and in the upper Chamber (3) opens via a siphon device (6). 7. Safety device with liquid absorber according to one of the preceding claims, characterized in that the reservoir (1) in a sleeve gleioh the Sleeves used for the fuel of the reactor are arranged. 8. Safety device according to one of the preceding Claims, characterized in that the liquid absorber consists of 6 lithium. 309881/0367