US3625819A - Attachment means for the superstructure above the core in a light water boiling reactor - Google Patents

Attachment means for the superstructure above the core in a light water boiling reactor Download PDF

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Publication number
US3625819A
US3625819A US704938A US3625819DA US3625819A US 3625819 A US3625819 A US 3625819A US 704938 A US704938 A US 704938A US 3625819D A US3625819D A US 3625819DA US 3625819 A US3625819 A US 3625819A
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US
United States
Prior art keywords
lid
shield
tank
attachment means
hook
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US704938A
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English (en)
Inventor
Bengt Martin Sodergard
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ABB Norden Holding AB
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ASEA AB
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Filing date
Publication date
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Publication of US3625819A publication Critical patent/US3625819A/en
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C5/00—Moderator or core structure; Selection of materials for use as moderator
    • G21C5/02—Details
    • G21C5/10—Means for supporting the complete structure
    • 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

  • ABSTRACT In a light water bolllng reactor, a superstructure comprising a steam treating unit and a lid for the moderator [54] ATTACHMENT MEANS FOR THE tank is arranged above the moderator tank and is detachable SUPERSTRUCTURE ABOVE THE CORE IN A for the purpose of interchange of fuel.
  • a shield substantially LIGHT WATER BOILING REACTOR concentric with the moderator tank and having a greater 6Claims,3l)rnwing Figs. diameter is attached to the tank in such a position that the upper end of the shield is at a level above the lid of the tank. [$2] [1.8.
  • a nuclear reactor of the boiling light water type usually comprises a steel vessel in which a moderator tank is arranged and above this a steam-treating unit.
  • the moderator tank contains the reactor fuel and is provided with a detachable lid to enable the exchanges of fuel which must sometimes be carried out. So that the lid can be removed leaving free access to the upper side of the moderator tank, the steam-treating unit consisting of steam separator and steam dryer must be able to be lifted out of the reactor.
  • the steam separator is connected to the moderator tank by a number of pipes fixed in the lid of the moderator tank.
  • the lid must be tightly closed on the moderator tank and must also be held by a certain force so that it is not lifted by the internal pressure in the moderator tank.
  • the lid has been fixed by means of bolts in a flange around the upper edge of the moderator tank. These bolts are thus placed rather far down in the reactor and are consequently not easily accessible.
  • the fact that the steamtreating unit normally has at least as great a diameter as the moderator tank also contributes to impeding the loosening or tightening of the flange joint bolts from the top of the reactor. This is done by means of rods which of course must be longer the further down in the reactor the flange joint is arranged. It may even be necessary to pass these rods through the casing of the steam-treating unit in order to reach the bolts, which of course does not facilitate the operation of these.
  • the shield Since the shield is moved up to a level above the lid of the moderator tank, the flange joint is moved nearer to the top of the reactor and the rods for tightening the flange joint from the top of the reactor can therefore be made shorter in comparison with known arrangements. Since, furthermore, the shield is made with a greater diameter than the moderator tank, the flange joint also has a greater diameter than in previously known arrangements. This means that said rods for manipulating the flange joint can pas outside the casing of the steam-treating unit and not, as in the known arrangements, be passed through the casing.
  • the shield is suitably connected to the moderator tank by means of radially positioned metal plate members which are so designed that they simultaneously form a centering control for the lid of the moderator tank during insertion.
  • the other part of the flange joint comprises a number of holders, each having a bolt joint consisting of a nut and screw.
  • the bolt joint is pivotably joined to a hook.
  • Holder and hook are suitably designed so that when the bolt joint is unscrewed the hook is flush-mounted in the holder but comes into engagement position when the bolt joint is screwed up.
  • the flange part arranged on the shield is provided with a suitable engagement for said hook.
  • connection pipes between the lid and the steam separator may be designed so that they form support members and can transmit compressive forces. In certain cases this is a disadvantage and according to a particular embodiment of the invention this can be avoided by providing the lid with supporting members in the form of a number of separate pressure rods which transmit compressive forces to the lid from the part of the flange joint which is not permanently fixed to the shield.
  • FIG. 1 shows a schematic section of a boiling light water reactor.
  • FIG. 2 shows the flange joint in more detail.
  • FIG. 3 is a detailed sketch of the holder and hook forming the flange joint.
  • l designates the outer casing of the reactor.
  • the moderator tank 2 with the lid 3 are arranged inside this outer casing.
  • Above the lid is the steam-treating unit 4 consisting of the steam separator unit the steam separator unit 18 and steam dryer I9. 5 is the shield, the lower part being fixed to the moderator tank and the upper part forming a mounting for the flange 6 which is arranged to fasten the steam-treating unit 4 and lid 3.
  • FIG. 2 The same designations are used in FIG. 2 as in FIG. I. It is also clear from FIG. 2 how the shield 5 is fixed to the moderator tank by means of radially positioned metal plates 7. Since the plates 7 are bevelled at the top towards the shield they form a centering control for the lid 3 during insertion. The edge 6 of the shield 5 is bent in in order to provide engagement for the hook 8. The hook is arranged in a holder 9 fixed to the steam-treating unit 4. A suitable number of holders 9 is arranged around the steam-treating unit 4. The hook 8 is operated by loosening or tightening the bolt 10 with the help of the tool 11. As is clear from the drawings it is possible to pass the tool 11 completely outside the casing of the steamtreating unit 4.
  • FIG. 2 also shows how compressive forces from the holder 9 are directly transmitted to the lid 3 by means of a rod 12.
  • a rod 12 is suitably arranged for each holder 9.
  • FIG. 3 shows more clearly the design and function of the holder 9 and the hook 8. 5 still designates the shield, 4 the steam-treating unit and 9 the holder itself.
  • the hook 8 is pivotably suspended in a bolt joint consisting of a screw 13 and a nut I4.
  • the hook 8 is further provided with a projection 15 which is influenced by a spring 16 arranged in the holder 9.
  • the joint is loosened by turning the nut 14 with the tool 11 the hook 8 first moves downward under the pressure of spring 16 and thus moves out of engagement with the shield.
  • the projection IS on the hook 8 meets the stop 17 in the holder 9 and the hook 8 returns into the holder 9.
  • the hook 8 cannot reengage when the steam-treating unit 4 is lifted up.
  • the hook 8 moves into the engagement position,influenced by the turning of nut I4 and the pressure from spring 16.
  • the joint is prestressed by continued turning of the nut.
  • the prestress is limited by torque limitation of the tool 11.
  • the nut is joumaled in a spherical seat which prevents the screw I3 from being flexurally stressed.
  • the transverse force arising is absorbed in a contact surface between the eyebolt and a flat tongue on the nut seat.
  • the thread surfaces should be extremely hard in order to reduce the risk of jamming. When choosing the material this is a requirement which is in opposition to the requirement for corrosion resistance.
  • Attachment means for a core superstructure arranged above the moderator tank in a boiling light water reactor which superstructure comprises a steam-treating unit and a lid for the moderator tank and is detachably arranged to expose the upper side of the moderator tank for fuel exchange, characterized in that a shield substantially concentric with the shell of the moderator tank and having a greater diameter than the tank is attached by means of intermediate members to the tank in such a position that the upper edge of the shield is at a level above the lid of the moderator tank and in that by means of a detachable flange joint absorbing upwardly acting force the superstructure is fixed to the upper part of the shield,
  • Attachment means according to claim 1 characterized in that the superstructure comprises a separate steam-drying unit to which one part of the flange joint is fixed.
  • Attachment means according to claim 2 characterized in that the supporting members comprise rods which are supported by the lid.
  • Attachment means according to claim 1 characterized in that the intermediate members fixing the shield to the shell of the moderator tank comprise radially positioned metal plate members which have means thereon to form a centering control for the lid of the moderator tank during insertion.
  • Attachment means according to claim 1, characterized in that the part of the flange joint fixed to the superstructure comprises a number of holders each having a bolt joint comprising a nut and screw and a hook pivotably joined to the bolt joint, and that the flange part fixed to the shield is designed to engage with said hooks.
  • Attachment means according to claim 5 characterized in that said hook is arranged to be flush-mounted in the holder when the bolt joint is unscrewed, but to come into engagement position when the boltjoint is screwed up.

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  • 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)
  • Structure Of Emergency Protection For Nuclear Reactors (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
US704938A 1967-02-14 1968-02-12 Attachment means for the superstructure above the core in a light water boiling reactor Expired - Lifetime US3625819A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE2015/67A SE324189B (no) 1967-02-14 1967-02-14

Publications (1)

Publication Number Publication Date
US3625819A true US3625819A (en) 1971-12-07

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ID=20259236

Family Applications (1)

Application Number Title Priority Date Filing Date
US704938A Expired - Lifetime US3625819A (en) 1967-02-14 1968-02-12 Attachment means for the superstructure above the core in a light water boiling reactor

Country Status (7)

Country Link
US (1) US3625819A (no)
DE (1) DE1639183B2 (no)
DK (1) DK120249B (no)
FR (1) FR1554253A (no)
GB (1) GB1207021A (no)
NO (1) NO125560B (no)
SE (1) SE324189B (no)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793142A (en) * 1971-10-11 1974-02-19 Asea Atom Ab Nuclear reactor having means for clamping a steam treating unit
EP0390373A2 (en) * 1989-03-27 1990-10-03 General Electric Company Steam-water separating system for boiling water nuclear reactors
US5319689A (en) * 1992-03-12 1994-06-07 General Electric Company Compactable phase-separator assembly for dual-phase nuclear reactor
US20070153964A1 (en) * 2006-01-04 2007-07-05 General Electric Company Method and device for stabilizing a steam dryer assembly in nuclear reactor pressure vessel
US20120014493A1 (en) * 2010-07-13 2012-01-19 Westinghouse Electric Company Llc Reactor head seismic support tie rod system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2806820A (en) * 1947-08-18 1957-09-17 Eugene P Wigner Neutronic reactor
US3144393A (en) * 1962-10-29 1964-08-11 Raber Marvin Subcooled liquiod inlet fog cooled nuclear reactors
US3150053A (en) * 1961-12-11 1964-09-22 Arthur J Goldman Steam-water mixing device for steam-cooled reactor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2806820A (en) * 1947-08-18 1957-09-17 Eugene P Wigner Neutronic reactor
US3150053A (en) * 1961-12-11 1964-09-22 Arthur J Goldman Steam-water mixing device for steam-cooled reactor
US3144393A (en) * 1962-10-29 1964-08-11 Raber Marvin Subcooled liquiod inlet fog cooled nuclear reactors

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3793142A (en) * 1971-10-11 1974-02-19 Asea Atom Ab Nuclear reactor having means for clamping a steam treating unit
EP0390373A2 (en) * 1989-03-27 1990-10-03 General Electric Company Steam-water separating system for boiling water nuclear reactors
EP0390373A3 (en) * 1989-03-27 1991-01-16 General Electric Company Steam-water separating system for boiling water nuclear reactors
US5319689A (en) * 1992-03-12 1994-06-07 General Electric Company Compactable phase-separator assembly for dual-phase nuclear reactor
US8311179B2 (en) 2006-01-04 2012-11-13 General Electric Company Methods for stabilizing a steam dryer assembly in a nuclear reactor pressure vessel
US20070153964A1 (en) * 2006-01-04 2007-07-05 General Electric Company Method and device for stabilizing a steam dryer assembly in nuclear reactor pressure vessel
US7596199B2 (en) * 2006-01-04 2009-09-29 General Electric Company Method and device for stabilizing a steam dryer assembly in nuclear reactor pressure vessel
US20120014493A1 (en) * 2010-07-13 2012-01-19 Westinghouse Electric Company Llc Reactor head seismic support tie rod system
WO2012009130A1 (en) * 2010-07-13 2012-01-19 Westinghouse Electric Company Llc Reactor head seismic support tie rod system
CN103069499A (zh) * 2010-07-13 2013-04-24 西屋电气有限责任公司 反应堆顶盖防震支承拉杆系统
EP2593941A1 (en) * 2010-07-13 2013-05-22 Westinghouse Electric Company LLC Reactor head seismic support tie rod system
JP2013538335A (ja) * 2010-07-13 2013-10-10 ウエスチングハウス・エレクトリック・カンパニー・エルエルシー 原子炉蓋耐震支持タイ・ロッド・システム
EP2593941A4 (en) * 2010-07-13 2015-04-22 Westinghouse Electric Corp PULLING SYSTEM FOR SEISMIC SUPPORT OF A REACTOR HEAD
US9324462B2 (en) * 2010-07-13 2016-04-26 Westinghouse Electric Company Llc Reactor head seismic support tie rod system
CN103069499B (zh) * 2010-07-13 2016-07-06 西屋电气有限责任公司 反应堆顶盖防震支承拉杆系统

Also Published As

Publication number Publication date
SE324189B (no) 1970-05-25
DE1639183A1 (de) 1971-03-11
DK120249B (da) 1971-05-03
DE1639183B2 (de) 1971-11-25
NO125560B (no) 1972-09-25
FR1554253A (no) 1969-01-17
GB1207021A (en) 1970-09-30

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