DE2346638C3 - Pressurized water nuclear reactor plant - Google Patents

Description

55

The invention relates to a pressurized water nuclear reactor installation mi! a reactor pressure vessel, the one in the reactor pit of a biological shield • is arranged, and with at least one primary coolant pipe connected to the reactor pressure vessel, which leads through the biological shield and concentrically and in the area of the reactor pit Distance is surrounded by a piece of pipe, whereby a cylindrical between him and the pipeline Ring cross-section arises, the pipe section having locking means formed by & 5 ring slides.

Such a nuclear reactor plant is known (US Pat. No. 53,853). Here the ring slide is through piston rings formed, which in the event of a crack in the wall of the reactor pressure vessel by the resulting Overpressure pushed in the axial direction of the main coolant line against the corresponding sealing mating surfaces which is intended to limit the amount of coolant that escapes.

By contrast, the invention makes the outer concentric pipeline for a different purpose exploited. The distance between the pipeline and the biological shield can result in a break the pipeline the coolant emerging from the primary circuit of the pressurized water reactor exerts undesirably high pressure on the outside of the reactor pressure vessel, since the pressure vessel is stored with a gap in its pit. That means the coolant would come out of the pipeline and over the Enter the annular gap in the reactor pit annulus surrounding the pressure vessel. With that would Forces become effective which are directed upwards, i.e. the forces present in normal operation are. In view of the large dimensions of the reactor pressure vessel and the considerable pressures in the Primary circuit stresses can arise from it, which with the known arrangement only with a very strong interception construction would have to be mastered.

The invention is based on the object of the pressurized water nuclear reactor installation mentioned at the outset Kind of designed so that undesirable pressure forces on the reactor pressure vessel in the event of a leak of primary coolant from a main coolant line are avoided.

According to the invention, the object set in a pressurized water nuclear reactor system is closer to that at the beginning defined type achieved in that the ring cross-section through the said closure means in normal operation is limited, but in the event of a leak in the pipeline, a relief cross-section for the Pipeline surrounding space to the outside, through the biological shield, can be released. To this Way prevents the pipe section the penetration of reactor coolant into the reactor pit, so that the The forces described cannot arise if the primary cooling circuit breaks. In normal operation however, there may well be a connection between the reactor pit and the pipe section in order to allow coolant to flow along the pipeline in the area of the biological shield.

The invention thus differs from other known nuclear reactor plants in which the Primary coolant pipes are concentrically surrounded by a pipe section (FR-PS 1523 111, DT AS 15 64 054 and 10 97 048 as well as GB-PS 9 80 386). In these known nuclear reactor systems, the is used existing radial gap only to make the pipeline mountable at all, and under certain circumstances to allow a certain accessibility to the pipeline, which is necessary for repeat tests on the Pipeline is necessary. In the arrangement according to DT-AS 15 64 054, the concentric pipes are used for the outward and return lines of the coolant.

In a preferred embodiment of the invention with one in the consisting of concrete biological shield concreted wall pipe is an annular gap between wall pipe and / or pipe section and Pipeline can be closed by a ring slide. The ring slide should be the one present in normal operation Interrupt the coolant flow through the pipe section and / or the wall pipe, as indicated above.

in order to prevent the reactor coolant from penetrating into the To prevent reactor pit. For this purpose, the ring slide can be fitted with a suitable motor drive, e.g. B. a hydraulic drive depending on suitable operating parameters such as pressure, temperature, Radiation intensity etc. can be adjusted. On the other hand, the ring slide can also be used as an automatic Blocking can be achieved when the ring slide with its acted upon surfaces itself is pressure-dependent is actuatable. This applies both in the event that a special ring slide is used and then, when the double pipe itself is movably arranged as a ring slide.

Another feature of an embodiment of the invention is that reactor pressure vessel and / or on the pipeline stops are provided, the forces with the help of the pipe section in the biological shield to initiate. With such attacks you can namely achieve that the reactor'.uck container in The area of the pipeline itself is determined where primarily with reaction forces in the case of flow is to be expected without the largely self-supporting pipe section being loaded.

For a more detailed explanation of the invention, an exemplary embodiment is given below with reference to the drawing described. Here, in Fig. 1 in a longitudinal section, a pipe connection of the outer Primary cooling circuit drawn on the reactor pressure vessel of a pressurized water reactor. Connection details shows Fig. 2 also in a section F i g. 3 shows a detail.

The reactor pressure vessel 1 has a cylindrical outer wall 2, from which essentially only pipe stubs 3 protrude, with which the light water used as the primary coolant from the reactor pressure vessel is led to a steam generator (not shown) and back. He's sitting in one cylindrical reactor pit 4, from which the nozzle 3 lead out radially.

To the nozzle 3, which is not shown in a manner around the circumference of the reactor pressure vessel are distributed, connect to the main coolant lines, the tubes of which are denoted by 5. These pipes lead, as you can see, at a distance 6 through the concrete 7 of the biological shield, which the reactor pressure vessel 1 surrounds. In the concrete 7 a wall pipe 8 is attached, which is attached to the end faces with two annular disks 9 on the Concrete 7 takes effect.

The distance between the pipe 5 and the Wall pipe 8 forms an annulus. In this one is concentrically approximately in the middle between the two Pipe section 10 is guided outside the concrete 7, that is to say in the gap 11 between the reactor pressure vessel 1 and the concrete 7 in the form of a ring 12 with approximately five times the wall thickness of the pipe section 10 continues.

At the end of the ring 12 facing the reactor pressure vessel 1, a flange 14 is welded, which points into the interior of the ring 12 and there with an edge i5 beveled at 45 ° on a correspondingly beveled outer surface 16 of the pipe socket 3 rests. Furthermore, in the interior of the ring 12 Spacers 18 are arranged with which the ring is centered with respect to the connection piece 3 and the tube 5.

The end of the pipe section 10 facing away from the reactor pressure vessel 1 also has a flange-like shape ring 20 angled outwards. This is, as shown in FIG. 3 shows on a larger scale, with a 3-bolt 21 with the interposition of disc springs 22 set, which on the flange 20, the pipe section 10 against a Press stop 23.

At the approach of the ring 12 on the pipe section 10, an annular disk 25 is articulated at 26, as shown in FIG. 2 shows. For this purpose, the annular disk 25 has a projection 27 in which a bolt 28 is articulated. The bolt 28 is screwed into the end of the ring \ 2. On the opposite side, the annular disk 25 carries a further pivot pin 30. A rod 31, which is guided by a stop 32, engages on this. Two nuts 33 are fastened on the rod, which determine the maximum opening movement of the annular disk 25 with their distance from the stop 32.

In the construction according to the invention, a limited flow is through a normal operation Air duct 35 possible in the direction of arrow 36, the pipe section 10 also being washed around. However, it arises in the Air duct 35 or the associated rooms z. B. increased pressure in an accident, the as Open the ring disk 25 acting on the non-return valve. This creates an enlarged opening cross-section created, which leads out of the reactor pit 4, so that a pressure relief takes place.

At a very high pressure in the space 39 of the reactor pit, which is separated by a thermal insulation 4 between the reactor pressure vessel 1 and the concrete 7 of the biological shield is also the Ring 12 pushed away from the reactor pressure vessel 1 against the action of the springs 22, which also a relief cross-section is released. Nevertheless, it is largely ruled out that about a rupture of the primary line 5 outflowing coolant in the interior of the reactor pit 4 an increased Pressure builds up. This coolant is namely with the pipe section 10 from the area of the biological shield led out. The thickened ring 12 ensures sufficient mechanical strength of the Pipe section 10 in the parts in which no pressure relief by a support on the concrete 7 or by a counter pressure. It can also be used as a stop on the connector 3 from Reactor pressure vessel 1 absorb outgoing forces.

1 sheet of drawings

Claims (5)

Patent claims: 1. Pressurized water nuclear reactor plant with a reactor pressure vessel in the reactor pit a biological shield is arranged, and with at least one on the reactor pressure vessel connected primary coolant pipeline that runs through the biological shield and in the area the reactor pit is surrounded concentrically and at a distance by a piece of pipe, whereby between him and the pipeline a cylindrical ring cross-section is created, the pipe section having closure means formed by ring slide, characterized in that by this closure means (25, 31 or 23, 21, 22) can be limited in normal operation of the annular groove (6) is, however, in the event of a leak in the pipeline (5), a relief cross-section for the pipeline (5) surrounding space to the outside, through the biological shield (7), can be released. 2. Pressurized water nuclear reactor installation according to claim 1 with a biological shield concrete wall pipe, characterized in that an annular gap between wall pipe (8) and Pipe section (10) and / or the pipe section (10) and the pipe (5) through an annular slide (12, 25, 31) is lockable. 3. Pressurized water nuclear reactor according to claim 1 or 2, characterized in that on Reactor pressure vessel (1) and / or stops are provided on the pipeline (5) that carry the forces Allow the help of the pipe section (10) to be introduced into the biological shield (7). 4. Pressurized water nuclear reactor installation according to claim 1, characterized in that the pipe back (10) can even be moved as a ring slide. 5. Pressurized water nuclear reactor plant according to claim 1 or 2, characterized in that between the pipe section (10) and the reactor pressure vessel (1) a reinforced ring (12), the main coolant line (5) Koi centrically surrounds with a gap and at one end with a flange (14) on The pipe socket (3) of the main coolant line is attached, but with its other end to the coaxial wall pipe forms the annular gap for the annular slide (25, 30), and that when one occurs very high pressure in the reactor pit space surrounding the reactor pressure vessel, this ring (12) is axially displaceable while releasing a relief cross-section.