DE2048881A1 - Fluid medium-cooled nuclear reactor - Google Patents

Description

f λ '"inta" ν / S! te

Dipl. Ing.C.Wallach
Dipl. Ing. G. Koch

Dr. T. Haib. ch

8 M "chen 2 ^{12 ti6S II / r}

Kaufingerstr 8, Tel. 24027Ö

5, OTil 1370

British Nuclear Design & Construction LiMitod _f Whetstone, Leicestershire, England, Grclilrit ^ nnien

StriSmungsraittelgski'.hlter nuclear reactor

The invention relates to a nuclear reactor flows ^ ttelgekühlten dee type in which the fuel feed Brennet off arrangements in in your Re & ktorcore provided fuel channel "introduced or removed from this ¹ who" the.

In a known embodiment of this type of reactor, standpipes lead in axial alignment with each of the fuel channels through the ceiling of a pressure vessel surrounding the reactor core, wiping the lower end of each standpipe and the associated fuel channel extends each a guide tube, which penetrates a horizontal partition, which the core from a cooling gas exit plenum separates · During normal operation of such a reactor, the cooling gas flows through each fuel assembly upwards and then through a neutron loyal pot in daa assigned guide tube and from diusem through a or several outlet openings provided in the guide tube into the outlet collecting chamber.

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When the reactor is being fed with fuel under Laatbetrieb, a used fuel assembly is removed from its fuel channel via the associated guide tube (in which it sits loosely with radial play) and the standpipe, and a new fuel assembly is introduced in its place, while at the same time the upstream cooling gate flow is in the guide tube stops when either the used or the new fuel assembly passes the outlet openings provided in the guide tube, the fuel assembly may vibrate radially _{c which can have} a detrimental effect on the structural cohesion and the strength of the fuel assembly,

This problem of the radial vibrations of a fuel assembly When loading under load, AnIaB has to consider and experiment in many ways given.

The invention thus relates to a central-flow cooled Nuclear reactor, which is used to connect a fuel channel provided in the reactor core and a fuel channel with it cooperating standpipe, which passes through a pressure vessel surrounding the core, has a guide tube, such «that a fuel assembly over the guide tube and the standpipe can be removed from the fuel channel or introduced into it, the guide tube having exit openings has, through which «in the operating state of the reactor KUhIströmmittel from the fuel channel can exit into a coolant outlet collecting chamber provided between the pressure vessel and the core.

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The invention is intended to address the aforementioned problem of the radial Vibrations of the fuel assembly leg. Pass through the exit openings in the guide tube and one considerable reduction of this tendency to radial vibrations can be achieved.

For this purpose, a Recktor -'1er mentioned type according to the invention provides that baffle or guide devices are provided outside the outlet openings, which radial · vibrations of the fuel arrangement in the ™

Passing the exit openings when inserting or significantly reduce when removing. It is preferably provided that the baffle or guide devices the Flow rate of the cooling fluid through the outlet openings limit to a predetermined value if there is no fuel assembly in the fuel channel.

According to expedient embodiments of the invention, provision can be made be that the baffle or guide device is attached to the guide tube} that the baffle or guide device one or more strip strips surrounding the guide tube at a radial distance from the outer openings, or that the baffle or guide device is at a radial distance from the exit openings around the guide tube has arranged around cylindrical jacket ring, which is old provided with several holes.

The following are two embodiments of the invention described on the basis of the drawing} show in this:

Fig. 1 is a partial sectional view of the lower end of a dl · top of the pressure vessel of a gas

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cooled standpipe penetrating the nuclear reactor as well as the upper end of a guide tube which works together with this standpipe and which leads upwards from a fuel channel provided in the reactor core _? voboi Fig. 1 illustrates a first embodiment of the invention;

Fig. 2 in a half-sectioned partial side view in gon ·

1 shows a second JP embodiment of the invention on an enlarged scale.

In Fig. 1, the lower end 2 of the standpipe k emerges from the ceiling of the concrete pressure vessel 6) the lower end 2 of the standpipe is designed with an enlarged radius in order to accommodate the upper end 8 of a guide tube 10, which is an annular part * 2 iur radial alignment and fixation between the guide tube and the standpipe

Eight gas outlet openings 14 are provided in the wall of the guide tube; LH remaining between these Auetritteöffnungen, extending in the axial direction 16 of the wall parts are by welded ribs 18 amplifies "According to the invention, are radially outside of the openings 14 and the ribs 18 are welded BAW baffle. Guide devices in the form of three baffles are provided, each of which consists of a steel tire running around the ribs 18 bsw. Steel band 20 exist.

During normal operation of the reactor «the cooling gas flows through a (not shown) arranged in the fuel channel Fuel assembly up into the guide tube 10 and

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passes through the outlet openings Ik in a Külxl gas-AustrittBsammelkammer 22, which Reaktoreore (not shown) between the pressure vessel and the ISTC provided in the fuel feed to the reactor under Leatbetrieb consumed Brennetoffanordnung from dom fuel passage via the lead-Unger ear 10 and the inner tube is removed h and replaced by a fresh fuel assembly which is introduced into the fuel duct in the same way. During the entire charging process, the cooling gas flow remains through the guide tube 10 and out of this * ™

uninterrupted through the outlet openings i4 hercus.

When testing a model that is in its structure and in its dimensions generally corresponded to those shown in Figo 1, there was a significant reduction in the radial Shock velocity between the fuel assembly and achieved the guide tube.

In FIG. 2, the same or corresponding parts are denoted by the same reference numerals as in FIG. Eight gas outlet openings Ik are provided in a thickened part 2k of the guide tube 10! Due to the increased wall thickness of the part Zk , additional reinforcement parts such as the ribs 18 used in the embodiment described above are unnecessary. A baffle or guide device in the form of a cylindrical casing ring 26 with several circular openings 28 is provided around the outlet openings 1Ί and welded to the guide tube 10.

In addition to a considerable reduction in the radial vibrations of the one passing the exit openings i4 The fuel-off arrangement can be made by the unuiantelungsring

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with a suitable choice of the number and size of the openings 28 the cooling gaa a tr toning through the access openings 1 * t limit a given acceptable value when calibrating no fuel assembly is located in the fuel channel and the flow of gas through the channel would otherwise be unimpeded.

As can be seen without further ado, the above-described The invention can basically be used for any arrangement of outlet openings in a guide tube it can also be seen without further ado that a large number of Licher forms and training for the guide or impact devices exist.

Patent claims »

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Claims (2)

Claims K 1 ·) StrÖmungsmitteigekühlter nuclear reactor, which for connection between a provided in the reactor core fuel channel and cooperating with the stand pipe which has a Core surrounding pressure vessel passes through "a guide tube, such _t that a fuel assembly on the guide tube and the inner tube from the fuel channel can be removed or introduced into this, wherein the guide tube has outlet openings through which, in the operating state of the reactor, cooling fluid can exit from the fuel channel into a coolant outlet collecting chamber provided between the pressure vessel and the core, characterized in that outside the outlet openings (1U) Impact or guide devices (20, Fig. 1; 26, Fig. 2) are provided, which significantly reduce radial vibrations of the fuel assembly when passing the outlet openings (i * t) when inserting or removing. 2. Nuclear reactor according to claim 1, characterized in that that the baffle or »guide devices (26, 26) reduce the throughput of the cooling flow medium through the outlet openings (iU) limit to a specified value if do not calibrate a fuel assembly in the fuel channel is located 3 «nuclear reactor according to claim 1 or 2, characterized in that that the baffle or guide device (20, 26) is attached to the guide tube (io). 209815/0840 k. Nuclear reactor according to one or more of the preceding claims, characterized in that the impact deflector has one or more strips of strips (20, Pig. 1) surrounding the guide tube (10) at a radial distance from the outlet openings (14). 5 · Nuclear reactor according to one or more of claims 1 to 3 »characterized in that the impact or guide device one at a radial distance from the outlet openings (i4, Fig. 2) arranged around the guide tube (10) has a cylindrical casing ring (26) which is provided with several LtSchi (28). 6 · Nuclear reactor according to one or more of the preceding claims »thereby
medium one gas 1st. Claims, characterized in that the Ktihlstrbmunge- ' 209815/0840 Blank page