JPS6321592A - Loop type liquid metal cooling fast breeder reactor - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] This invention reduces the diameter of the reactor vessel by suspending the reactor core from the coolant inlet piping. It concerns a loop-type liquid metal cooled fast breeder reactor that reduces the

[Prior Art] Conventionally, in a loop-type liquid metal cooled fast breeder reactor, the reactor core is fixed to a reactor vessel 2 suspended from a deck structure 3 at the top of the reactor, as shown in FIG. It was supported by a core support structure 5 extending toward the center of the reactor vessel 2.

[Problems to be Solved by the Invention] However, the core support structure 5 includes a coolant inlet pipe 7 that is introduced from outside the reactor vessel and communicates with the high-pressure blenum 6 located at the lower part of the reactor core 1, and a fuel It is necessary to provide a hole through which the in-core relay tank 8 for replacement passes, and it is also necessary to firmly support the reactor core in the event of an earthquake, so a highly rigid, thick-walled forged material is used. Although not shown in the drawings, reinforcing ribs must be provided to reinforce the structure.

The present invention has been made in view of the above circumstances, and solves the problem of clutter in the conventional technology, and provides a low-cost loop-type liquid metal fast breeder reactor with a reduced reactor vessel diameter. The purpose is to provide the following.

(B) Structure of the invention [Means for solving the problem] In response to this objective, the loop type liquid metal cooled fast breeder reactor of the present invention is characterized in that the core is suspended and supported by coolant inlet piping. .

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment.

FIG. 1 is a longitudinal sectional view of a loop type liquid metal cooled fast breeder reactor according to an embodiment of the present invention, and FIG. 2 is a plan view of the reactor core.

In FIGS. 1 and 2, reference numeral 2 indicates a reactor vessel. The reactor vessel 2 is suspended from a deck structure 3 as in the past, and a guard vessel 4 is installed on the outside thereof. Reference numeral 1 indicates a reactor core, and the reactor core 1 is composed of a large number of fuel assemblies (not shown), and a core tank 1.
It is supported on a core support plate 9 within the core support plate 9. The core support plate 9 has a large number of coolant passage holes a for supplying coolant (sodium) to the core. The core barrel 10 extends to a bottom plate 13, and a plurality of coolant passage holes are bored in a portion corresponding to the high-pressure blemish 6. The above configuration is completely the same as the conventional example shown in FIG. Although each of the reactor vessel 2, deck structure 3, guard vessel 4, core support plate 9, core barrel 10, and bottom plate 13 has a thickness, they are simply shown by lines to simplify the diagram. .

A plurality of coolant inlet pipes 7 are provided, and these are introduced into the reactor vessel 2 from the outside of the reactor vessel 2 through the vessel wall, and the direction is set at 90° inside the deck structure 3.
It extends vertically towards the bottom of the reactor vessel 2. Moreover, this coolant inlet pipe 7 is firmly joined to the deck structure at the lower end surface C portion of the deck structure 3.

The loop type liquid metal cooled fast breeder reactor of the present invention is equipped with an outer cylinder 11 on the outside of a core tank 10, the lower end of which is attached to a bottom plate 13, and the upper end is attached to an annular upper plate 12 by means of welding or the like. Watertightly joined. That is, a high-pressure brenum 6 partitioned by an outer cylinder 11, an upper plate 12, and a bottom plate 13 is formed outside the core Fa10. A plurality of coolant inlet pipes 7 are joined to the annular upper plate 12 by welding, and the coolant descends within the coolant inlet pipes 7 as indicated by the arrows in the figure, and is sufficiently pumped in the annular high-pressure blennium section. After being stirred, it flows into the high-pressure blenum below the core 1, where the flow direction is reversed and flows into the core 1.

That is, the entire core structure including the core 1 is suspended and supported by the coolant inlet pipe 7.

Reference numeral 15 indicates a steady rest, and the steady rest 15 is attached to the outer cylinder 11 side or the reactor vessel 2 side so as to leave a slight gap between the outer cylinder 11 and the reactor vessel 2 to absorb the heat displacement of 8 Jt. (example shown).

Reference numeral 16 is a coolant outlet pipe.

[Function] For example, in a 100,100O, 4-loop plant, a coolant inlet pipe of approximately 40B (1016 mφ) is used, and the entire reactor core is suspended and supported by the four coolant artificial pipes. In this case, the wall thickness of the pipe is 30II1
1, the stress due to its own weight and internal pressure is 3.5Kg/m2
, and the allowable value is BKgl 2 (SUS304 5
25℃.

S value of 3×105h). Also, if the load due to the vertical S2 earthquake is 1.5g, the stress due to this is 2
．． 8 to 9/m. In the case of a horizontal S2 earthquake, the load can be received by the photo stops placed above and below the core barrel in the axial direction, so the stress generated on the piping side at this time is 1.8 Kg/aI2, and the self-weight +Internal pressure +Vertical S2
The stress due to the earthquake + horizontal S2 ground cloud is 8.1 to 9/m2, but the allowable fa11Kg/mlR2 (SUS
304 at 525°C).

In addition, the core is suspended and supported by three coolant inlet pipes of 100,100 O, 3-lube plant technology, and a pipe diameter of about 46 B (1168 s*φ).

In this case as well, if the wall thickness of the pipe is 305II, natural hair (
8KS/l1III), and the stress due to own weight + internal pressure + vertical S2 earthquake + horizontal S2 earthquake is 9.3 Kfl/m2 < 3 (9/m2 in 11,0), ■ All of which are within the allowable values, so cooling The reactor core can be sufficiently suspended and supported by the material inlet piping, and there is no need for a core support structure on the side as in the conventional method, making it possible to reduce the diameter of the reactor vessel.

(c) Effects of the invention According to this invention, the coolant inlet piping is also used as core support means, so the high rigidity core support f on the side of the core is
iG items can be deleted. Therefore, it is possible to reduce the diameter of the reactor vessel, and it is possible to obtain a loop-type liquid metal cooled fast breeder reactor with fewer trapped materials, contributing to a reduction in plant costs.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a loop-type liquid metal cooled fast breeder reactor according to an embodiment of the present invention, and FIG. 2 is a plan view of the core of the same.
FIG. 3 is a longitudinal sectional view of a conventional loop type liquid metal cooled fast breeder reactor. 1... Reactor core 2... Reactor vessel 3... Deck structure 6... High pressure blennium 7... Coolant inlet piping 9... Core support plate 10... Core barrel 1
1...Outer cylinder 12...Top plate 13...Bottom plate 1
5...Photo stills Figure 1 Figure 3

Claims (1)

[Claims] A loop-type liquid metal cooled fast breeder reactor characterized by a core suspended and supported by coolant inlet piping.