Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
  • G21C19/02—Details of handling arrangements
  • G21C19/06—Magazines for holding fuel elements or control elements
  • G21C19/07—Storage racks; Storage pools
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• the present invention relates to the technical sector of the nuclear industry, including the technical sector racks storage fuel assemblies or other racks for storage of waste, which racks are embedded in pools for cooling said fuel assemblies.
• the invention relates in particular to a protection assembly of a liner of a deactivation pool or a pool for storing and / or storing the fuel; in the following the term cooling pool will be retained.
• Storage racks also commonly referred to as “racks”, are in the form of crates in which fuel assemblies or highly irradiating waste are stored vertically. These racks are then embedded and deposited at the bottom of a pool for cooling said fuel assemblies.
• a vacuum rack usually weighs from a few tons to several tens of tons and can contain from 50 to 100 fuels, each weighing several hundred kilos depending on the nature of the fuel or waste.
• the storage racks generally including feet, are placed directly on the liner of the pool which is usually stainless steel.
• the liner is of small thickness, of the order of 3 to 6 millimeters, and consists of large sheets welded together.
• the weld zones generally form a prominent projection relative to the surface of the liner thus defined.
• the liner can be subjected to strong mechanical stress, especially in case of earthquakes. Indeed, during an earthquake, the racks that are simply placed at the bottom of the pool slide freely on the surface of the stainless steel liner and may be caused to move relative to the pool bottom. Depending on the power level of the earthquake the movement of the racks can be from a few millimeters to several tens of centimeters.
• Another difficulty lies in the fact that the feet of the racks abut, during the movement of said racks, against the protuberance of the pool bottom and in particular against the prominent weld lines of the constituent plates of the liner causing locally extremely important constraints with risks of tearing of said liner.
• One of the aims of the invention is therefore to remedy the aforementioned drawbacks by proposing a protection assembly for a liner of a deactivation pool or a pool for storing and / or storing or cooling the fuel. fuel assemblies or irradiating waste stored in a storage rack.
• a protection assembly for a liner of a deactivation pool or a pool for storing and / or storing or cooling the fuel. fuel assemblies or irradiating waste stored in a storage rack.
• it has been developed a set of protection of a liner of a storage pool and / or storage of fuel assemblies or cooling fuel assemblies stored in a storage rack, said liner consisting of large stainless steel sheets welded together.
• the protection assembly is composed of a protective sheet made of stainless steel or other material having a high coefficient of friction with the liner, of the same grade, that is to say of same material as the liner where of a grade such that it generates a high coefficient of friction in contact with the liner whose dimensions are such that it is able to cover the surface of the liner or part of the surface of said cooling pool , located under the rack, and sliding pads made of a material with a low coefficient of friction with stainless steel.
• Said protective sheet is intended to be arranged on the liner of the pool, and the pads are intended to be fixed under feet that includes the storage rack or directly under the rack to make contact with the protective sheet.
• the protective sheet does not include prominent welds, there is no problem obstacle to sliding racks in the pool.
• the invention makes it possible to considerably reduce the stresses on the liner since the horizontal forces are small because of the non slip of the protective sheet on the liner. There is also little or no slip between the liner and the pool concrete.
• the protective plate may comprise on its surface intended to be in contact with the liner, grooves adapted to accommodate the protruding welds of the constituent laminations of said liner. A discontinuity of the protective plate is also possible when the pad remains in contact with all or part of the protective plate.
• the coefficient of friction of the pads with the stainless steel is of the order of 0.1-0.4.
• FIG. 1 is a diagrammatic view illustrating a storage rack for fuel assemblies placed on a liner of a cooling pool not equipped with the protection assembly according to the invention
• Figure 2 is a schematic view illustrating the protection assembly according to the invention, the figure being in enlarged view at one of the feet of the rack.
• FIG. 1 illustrates the current state of the art.
• This FIG. 1 shows a storage rack (1) for fuel assemblies placed on a liner (2) of a cooling pool (3).
• the liner (2) consists of large sheets (4) welded together.
• Figure 2 illustrates the solution proposed by the invention. It represents the protection assembly (5) according to the invention. It consists of a protective plate (6) made of stainless steel and sliding pads (7) for the feet (8) of the rack (1).
• the protective sheet (6) has dimensions such that it is able to cover the surface or part of the surface of the liner (2) of the cooling pool (3) located under the rack or under the feet (8) of which he is equipped. The chosen materials and the surface condition generate a high coefficient of friction in contact with the liner.
• the protective sheet (6) typically has a thickness of between two and six millimeters.
• the pads (7) are made of a material with a low coefficient of friction with stainless steel, a coefficient of preference of 0.1 to 0.4, and in particular 0.15.
• the protective plate (6) is arranged on the liner (2) of the pool (3), and the pads (7) are fixed under the rack (1) (usually equipped with feet) to make contact with the sheet metal. protection (6).
• the protective plate (6) comprises on its surface facing the liner (2), grooves (9) or recesses, suitable for housing the welds (10) or protuberances of the constituent laminations of the liner (2) to limit the mechanical stresses at said welds (10), and to ensure the flatness of the protective sheet (6).

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Monitoring And Testing Of Nuclear Reactors (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)
• Butt Welding And Welding Of Specific Article (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (3)

Family Cites Families (3)

• 2013
  • 2013-11-21 FR FR1361469A patent/FR3013499B1/fr active Active
• 2014
  • 2014-10-31 EP EP14806001.5A patent/EP3072135A1/de not_active Ceased
  • 2014-10-31 WO PCT/FR2014/052773 patent/WO2015075340A1/fr active Application Filing

Non-Patent Citations (2)

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