Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F7/00—Shielded cells or rooms
  • G21F7/02—Observation devices permitting vision but shielding the observer
  • G21F7/03—Windows, e.g. shielded
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F7/00—Shielded cells or rooms
  • G21F7/02—Observation devices permitting vision but shielding the observer

Definitions

• the present invention relates to the technical field of protection against ionizing radiation.
• It relates more particularly to a radioprotective screen intended to be fixed to the periphery of an opening made in a wall separating a space subjected to ionizing radiation (called hot space), and a space not subjected to ionizing radiation (called space cold).
• hot space a space subjected to ionizing radiation
• space cold a space not subjected to ionizing radiation
• a shielded cell partitioning a space subjected to ionizing radiation comprising a metallic interior coating and at least one anti-radiation window allowing visual access from the outside to the inside of said shielded cell, which anti-radiation window comprises a sheath embedded in a concrete wall, which sheath receives an armored porthole which is associated with a radioprotective screen fixed to the periphery of an opening made in said metallic interior coating.
• These shielded cells are surrounded by walls adapted to provide effective protection against ionizing radiation, and they generally include at least one window allowing visual control, from the outside, of the operations carried out internally (see for example US 7 257 927, EP 0 430 687, US 3 505 525, FR 1 333 746).
• Such windows can comprise a sheath, embedded in a concrete wall, which sheath receives an armored porthole composed of a cast iron frame incorporating a plurality of anti-radiation glass slabs.
• the shielded enclosure may include a radioprotective screen, positioned opposite the shielded window.
• This protective radio screen also known as “alpha ice”
• alpha ice is fixed around the periphery of an opening made in a metallic interior coating which covers the walls of the armored enclosure.
• the radioprotective screen in question comprises a wall made of transparent material, the periphery of which is sandwiched in a supporting assembly made up of a fixing frame and a subframe, allowing fixing by welding with the interior coating of the shielded enclosure.
• the wall made of transparent radioprotective material is delimited by a first face, intended to be oriented towards the exterior “cold space” side, and by a second face intended to be oriented towards the interior “hot space” side.
• a peripheral edge of this first wall face comes to bear against a bearing face of the subframe by through a seal made of organic material (generally EPDM or neoprene).
• the fixing frame is provided with support means, with seal, against a peripheral edge of the second face of the wall made of transparent material.
• the present invention proposes a radioprotective screen intended to be fixed on the periphery of an opening made in a wall separating a space subjected to ionizing radiation, said hot space, and a space not subjected to ionizing radiation, called cold space, which radio protective screen comprises a wall made of transparent material, said wall made of transparent material comprising a first face intended to be oriented towards said cold space and a second face intended to be oriented towards said hot space,
• said radioprotective screen comprising a fixing frame provided with means for bearing against a peripheral edge of the other of said first face or second face of said wall made of transparent material,
• support means comprise a longitudinal support structure comprising a contact surface with the peripheral edge of the first face or of the second face facing said wall made of transparent material
• radioprotective screen further comprises securing means for securing together said subframe and said fixing frame
• this radioprotective screen being characterized in that said support means comprise elastic return means adapted to apply pressure against said longitudinal support structure in the direction of said wall made of transparent material.
• gaskets that are well resistant to ionizing radiation, in particular gaskets made of inorganic material (advantageously gaskets made of soft metal, that is to say malleable or ductile, chosen from among lead, copper, tin or cadmium, in the pure state or in the form of an alloy), or graphite gaskets.
• gaskets made of inorganic material that is to say malleable or ductile, chosen from among lead, copper, tin or cadmium, in the pure state or in the form of an alloy
• graphite gaskets are as follows:
• the elastic return means consist of a plurality of spring members regularly or at least approximately regularly distributed around the periphery of said fixing frame;
• the longitudinal support structure comprises a metal pressure profile associated with an added support profile constituting said contact surface with the peripheral edge of the face facing the wall made of transparent material and forming a seal;
• said attached bearing profile is made of a material chosen from (i) soft metals, preferably lead, copper, tin and cadmium, in the pure state or in the form of an alloy, and ( ii) graphite;
• the elastic return means are associated with pressure adjustment screws adapted to allow adjustment of the pressure applied by said elastic return means on said longitudinal support structure;
• At least some of said Belleville washers are each associated with a pressure adjustment screw.
• the present invention also relates to a shielded cell partitioning a space subjected to ionizing radiation, comprising a metallic interior coating and at least one anti-radiation window allowing visual access from the outside to the inside of said shielded cell, which anti-radiation window.
• -radiation comprises a sheath embedded in a concrete wall, which sheath receives an armored window which is associated with a radioprotective screen as defined above, fixed to the periphery of an opening made in said metallic interior coating.
• FIG. 1 is a schematic vertical sectional view which illustrates an armored cell incorporating an anti-radiation window equipped, on the hot space side, with a radiation shield in accordance with the invention
• FIG. 2 shows the radiation shield of the anti-radiation window illustrated in Figure 1, seen from the front from the hot space side of the shielded cell;
• FIG. 3 is a sectional view along the section plane 3-3 of Figure 2;
• the armored cell 1 illustrated in Figure 1 is delimited by concrete walls 2 (partially shown) in one of which is provided an anti-radiation window 3.
• the concrete walls 2 have a significant thickness which can go up to 1.5 meters.
• the anti-radiation window 3 is adapted to allow a person P located outside the armored cell 1, cold space side F, to monitor operations carried out on radioactive products within the internal hot space C.
• This anti-radiation window 3 comprises a sheath 31 in the form of a metal frame, for example made of steel or cast iron, embedded in the concrete wall 2 of the armored cell 1, this sheath 31 receiving an armored window 32 consisting of a block optic formed here of two slabs of lead glass 321 and 322.
• the inside of the armored cell 1 comprises a metal coating 4 in which an opening 41 is made opposite the anti-radiation window 3, and on the periphery of which the opening 41 is fixed by welding the periphery of 'a protective radio screen 5, detailed in Figures 2 and 3.
• the metal coating 4, also called “casing”, is advantageously made of stainless steel.
• the radioprotective screen 5 comprises a wall 6 made of transparent material, delimited by a first face 61 intended to be oriented towards the side of the cold space F of the shielded cell 1 (that is to say oriented towards the slabs. lead glass 321 and 322), and a second face 62 intended to be oriented towards the hot space C.
• first and second faces 61, 62 of the wall 6 made of transparent material are connected by an edge 63.
• the wall 6 of transparent material can be made of glass.
• This radioprotective screen 5 also comprises a peripheral structure 7, formed of a counterframe 8 and a fixing frame 9, which peripheral structure 7 is adapted to hold the wall 6 made of transparent material and to allow its fixing to the metal coating 4 of the shielded enclosure 1.
• the perimeter of the wall 6 of transparent material is sandwiched between the subframe 8 and the fixing frame 9, and securing means, here in the form of a screw 10, ensure the securing between these counterframe. 8 and fixing frame 9.
• the periphery of the wall 6 made of transparent material is positioned in a rebate 81 of the subframe 8, with a peripheral edge 61 1 of the first face 61 of this wall 6 made of transparent material which is positioned in said rebate 81, against a bearing face 811 of the subframe 8, by means of a seal 11.
• the periphery of the wall 6 made of transparent material is positioned in a rebate 91 of the fixing frame 9, with a peripheral edge 621 of the second face 62 of this wall 6 made of transparent material which is positioned in said rebate 91, facing the face 911 of a wing 912 of this rebate 91; and the fixing frame 9 is provided with means 12 for bearing against said peripheral edge 621 of the second face 62 of said wall 6 made of transparent material.
• These means 12 include:
• the attached support profile 1212 is associated with the metal pressure profile 121 1 by gluing or by simple interlocking of complementary shapes.
• the elastic return means consist of a plurality of spring members in the form of Belleville washers 122 regularly or at least approximately regularly distributed around the periphery of the fixing frame 9, which are each interposed between the metal pressure profile 121 1 and the active end 1231 of pressure adjustment screws 123.
• the pressure adjustment screws 123 pass through the flange 912 of the rebate 91 of the fixing frame 9 via a threaded hole 9120. And the end 1232 of the pressure adjustment screws 123, which is opposite to that 1231 cooperating with the associated Belleville washer 122, is accessible from the outside of the fixing frame 9. This opposite end of screw 1232 cooperates with a locking locknut 124 and has a recess 1233 for its rotation operation by a suitable tool (such as a wrench, screwdriver, etc.).
• a suitable tool such as a wrench, screwdriver, etc.
• the metal pressure profile 121 1 is for example made of steel, stainless steel (stainless steel), bronze or brass.
• the seals 1 1 and 1212 can be made of inorganic material. They can thus be made of soft metal (that is to say malleable / ductile), preferably chosen from lead, copper, tin or cadmium (in the pure state or in the form of alloys) .
• They can also be made of graphite.
• the two joint structures 1 1 and 1212 are made of the same material.
• the fixing frame 9 and the subframe 8 are in contact with each other at the level of a contact plane 13 through which the securing screws 10 pass.
• These securing screws 10 are regularly or at least approximately regularly distributed over the periphery of the fixing frame 9 and of the subframe 8, for example at the same pitch as the pressure adjustment screws 123.
• the radioprotective screen 5 can be fixed in the other direction on the peripheral edge of the opening 41, that is to say with the subframe 8 facing the hot space side. C and the fixing frame 9 facing the cold space side F (in particular to allow the dismantling of the fixing frame 9 from the cold space side
• the support means 12 make it possible to apply a permanent pressure on the seal 1 1 sandwiched between the wall 6 of transparent material and the support face 81 1 of the rebate 81 of the counter. frame 8, and also on the seal 1212 sandwiched between the wall 6 of transparent material and the fixing frame 9.
• seals 11 and 1212 which are resistant to ionizing radiation, but which, by their nature, may have a tendency to collapse or creep slightly over time.
• the support means 12 then constitute an elastic creep compensation system by maintaining the pressure on the seals.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
• Securing Of Glass Panes Or The Like (AREA)
• Building Environments (AREA)
• Gasket Seals (AREA)
• Transforming Electric Information Into Light Information (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

Country Status (7)

Families Citing this family (2)

Family Cites Families (10)

• 2019
  • 2019-02-05 FR FR1901123A patent/FR3092431B1/fr active Active
• 2020
  • 2020-02-04 US US17/428,134 patent/US11488738B2/en active Active
  • 2020-02-04 EP EP20709643.9A patent/EP3921853B1/de active Active
  • 2020-02-04 WO PCT/FR2020/050184 patent/WO2020161432A1/fr unknown
  • 2020-02-04 KR KR1020217024872A patent/KR20220030919A/ko active Search and Examination
  • 2020-02-04 JP JP2021545365A patent/JP7416812B2/ja active Active
  • 2020-02-04 CA CA3128446A patent/CA3128446A1/fr active Pending

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