JP2018017609A - Core of boiling water reactor - Google Patents

Core of boiling water reactor Download PDF

Info

Publication number
JP2018017609A
JP2018017609A JP2016148136A JP2016148136A JP2018017609A JP 2018017609 A JP2018017609 A JP 2018017609A JP 2016148136 A JP2016148136 A JP 2016148136A JP 2016148136 A JP2016148136 A JP 2016148136A JP 2018017609 A JP2018017609 A JP 2018017609A
Authority
JP
Japan
Prior art keywords
handle
core
fuel
lattice
boiling water
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.)
Granted
Application number
JP2016148136A
Other languages
Japanese (ja)
Other versions
JP6752072B2 (en
Inventor
藤本　清志
Kiyoshi Fujimoto
清志 藤本
高橋　志郎
Shiro Takahashi
志郎 高橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi GE Nuclear Energy Ltd
Original Assignee
Hitachi GE Nuclear Energy Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi GE Nuclear Energy Ltd filed Critical Hitachi GE Nuclear Energy Ltd
Priority to JP2016148136A priority Critical patent/JP6752072B2/en
Priority to PCT/JP2017/025514 priority patent/WO2018021044A1/en
Publication of JP2018017609A publication Critical patent/JP2018017609A/en
Application granted granted Critical
Publication of JP6752072B2 publication Critical patent/JP6752072B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/30—Assemblies of a number of fuel elements in the form of a rigid unit
    • G21C3/32—Bundles of parallel pin-, rod-, or tube-shaped fuel elements
    • G21C3/33—Supporting or hanging of elements in the bundle; Means forming part of the bundle for inserting it into, or removing it from, the core; Means for coupling adjacent bundles
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
    • G21C15/02—Arrangements or disposition of passages in which heat is transferred to the coolant; Coolant flow control devices
    • 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

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Structure Of Emergency Protection For Nuclear Reactors (AREA)
  • Monitoring And Testing Of Nuclear Reactors (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a core of a boiling water reactor which can improve work efficiency of periodic inspection or fuel replace while preventing fuel rising in an operation.SOLUTION: In a core of a boiling water reactor 21 in which fuel assemblies 1 are arranged with triangle grillwork arrangement densely and a control rod 11 with Y-shaped horizontal section is inserted in the center of the three fuel assemblies (1a-1c), the long sides (71a-71c) of top surface of handles (7a-7c) provided to the three fuel assemblies (1a-1c) surrounding the control rod 11 with Y-shaped horizontal section are arranged to face the center of the control rod 11 with Y-shaped horizontal section, and a fuel rising preventing member 31 arranged upside of the top surface of the handle and preventing rising upside of the fuel assembly.SELECTED DRAWING: Figure 1

Description

本発明は、沸騰水型原子炉の炉心に係り、特に、複数体の燃料集合体が三角格子状配列にて稠密に配され、相互に隣接する３体の燃料集合体間に水平断面がＹ字型の制御棒が挿入される沸騰水型原子炉の炉心に関する。   The present invention relates to a core of a boiling water reactor, and in particular, a plurality of fuel assemblies are densely arranged in a triangular lattice arrangement, and a horizontal cross section between three fuel assemblies adjacent to each other is Y. The present invention relates to the core of a boiling water reactor into which a letter-shaped control rod is inserted.

炉心に燃料集合体が三角格子状配列にて稠密に装荷される軽水増殖炉が開発されている。例えば、特許文献１には、軽水増殖炉に装荷される燃料集合体と炉心上部支持板との間に設けたタブと板ばねにより燃料集合体の横への移動を防止し、燃料集合体のギャップ保持と制御棒の挿入性を確保する構成が記載されている。また、特許文献１には、燃料集合体と炉心上部支持板との間にホールドダウンスプリングを設け、燃料集合体の浮き上がりを防止する構成が開示されている。
また、加圧水型原子炉であるものの、特許文献２には、燃料集合体の浮き上がりを防止するために、燃料集合体上部ノズルの上面四辺に板ばねを配する構成が記載されている。また、加圧水型原子炉では制御棒を挿入する方式及び制御棒を挿入する場所が、沸騰水型原子炉とは異なり、制御棒を燃料集合体中央に上部より挿入するため、制御棒挿入時に不要な燃料集合体移動用のハンドルは取り外される。 A light water breeder reactor has been developed in which fuel assemblies are densely loaded in a triangular lattice arrangement in the core. For example, Patent Document 1 discloses that a tab and a leaf spring provided between a fuel assembly loaded in a light water breeding reactor and a core upper support plate prevent movement of the fuel assembly to the side, A configuration is described that ensures gap retention and control rod insertion. Patent Document 1 discloses a configuration in which a hold-down spring is provided between the fuel assembly and the core upper support plate to prevent the fuel assembly from being lifted.
In addition, although it is a pressurized water reactor, Patent Document 2 describes a configuration in which leaf springs are arranged on the upper four sides of the upper nozzle of the fuel assembly in order to prevent the fuel assembly from floating. Unlike pressurized water reactors, control rods are inserted in the center of the fuel assembly from the top, and the control rod insertion method and the location where the control rods are inserted are not required when inserting the control rods. The handle for moving the fuel assembly is removed.

特開平８−２２０２７６号公報JP-A-8-220276 特開平８−３６０７８号公報JP-A-8-36078

しかしながら、特許文献１に記載される構成では、炉心上部に炉心上部支持板を設置し、炉心上部支持板と水平断面六角形状の燃料集合体を上部支持機構（ホールドダウンスプリング）で支持することで、燃料浮き上がりを防止している。炉心上部支持板には、各燃料集合体に対して上部支持機構を設置するスペースが必要となるため、炉心上部支持板に設ける冷却材流路は、水平断面六角形状の燃料集合体の大きさより小さくなっている。原子炉の冷却材循環ポンプ等への機器の負担を軽減するために、炉心上部支持板での圧損を低減する必要があり、そのためには広い冷却材流路を確保する必要が有る。また、上部支持機構としてホールドダウンスプリングを用いて燃料浮き上がりを防止しているが、複数の燃料集合体に対してホールドダウンスプリングを設置する必要があり、取り付けが困難となる。
また、特許文献２に記載される構成では、原子炉運転中、燃料集合体の中央に上方から制御棒を挿入する方式であるがゆえ、燃料集合体を移動するためのハンドルは取り外されている。従って、燃料交換時において、ハンドルを取り付ける作業が必要となり、燃料交換作業の効率化を図ることはできない。
そこで、本発明は、運転時における燃料浮き上がりを防止しつつ、定期検査或は燃料交換等の作業効率を向上し得る沸騰水型原子炉の炉心を提供する。 However, in the configuration described in Patent Document 1, a core upper support plate is installed in the upper part of the core, and the upper core support plate and the fuel assembly having a hexagonal horizontal cross section are supported by an upper support mechanism (hold down spring). , Preventing fuel lift. Since the core upper support plate requires a space for installing the upper support mechanism for each fuel assembly, the coolant flow path provided in the core upper support plate is larger than the size of the fuel assembly having a horizontal cross section of hexagonal shape. It is getting smaller. In order to reduce the burden of equipment on the reactor coolant circulation pump and the like, it is necessary to reduce the pressure loss at the core upper support plate, and to that end, it is necessary to secure a wide coolant flow path. In addition, although a hold-down spring is used as an upper support mechanism to prevent the fuel from floating, it is necessary to install hold-down springs for a plurality of fuel assemblies, which makes attachment difficult.
Further, in the configuration described in Patent Document 2, since the control rod is inserted from above into the center of the fuel assembly during the operation of the reactor, the handle for moving the fuel assembly is removed. . Therefore, it is necessary to attach a handle when changing the fuel, and the efficiency of the fuel changing operation cannot be improved.
Therefore, the present invention provides a core of a boiling water reactor that can improve the working efficiency of periodic inspection or fuel replacement while preventing the fuel from floating during operation.

上記課題を解決するため、本発明は、燃料集合体が三角格子状配列で稠密に配置され、３体の燃料集合体の中心に水平断面Ｙ字型の制御棒が挿入される沸騰水型原子炉の炉心であって、前記燃料集合体は、前記水平断面Ｙ字型の制御棒を囲む３体の燃料集合体に設けられるハンドルの上面の長辺又は短辺が、前記水平断面Ｙ字型の制御棒の中心に向くように配され、前記ハンドルの上面の上方に配され、前記燃料集合体の上方への浮き上がりを抑制する燃料浮き上がり防止部材を備えることを特徴とする。   In order to solve the above problems, the present invention provides a boiling water atom in which fuel assemblies are densely arranged in a triangular lattice arrangement, and a control rod having a Y-shaped horizontal section is inserted in the center of the three fuel assemblies. A core of a reactor, wherein the fuel assembly is configured such that a long side or a short side of an upper surface of a handle provided on three fuel assemblies surrounding the horizontal cross-section Y-shaped control rod has a horizontal cross-section Y-shape. The fuel rod is disposed so as to face the center of the control rod, is disposed above the upper surface of the handle, and includes a fuel floating prevention member that suppresses the fuel assembly from floating upward.

本発明によれば、運転時における燃料浮き上がりを防止しつつ、定期検査或は燃料交換等の作業効率を向上し得る沸騰水型原子炉の炉心を提供することが可能となる。
上記した以外の課題、構成及び効果は、以下の実施形態の説明により明らかにされる。 ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the core of the boiling water nuclear reactor which can improve working efficiency, such as a periodic inspection or a fuel exchange, preventing the fuel floating at the time of a driving | operation.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

本発明の一実施例に係る実施例１の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。1 is a partial plan view of a reactor core showing a positional relationship between a fuel floating prevention member and a fuel assembly according to an embodiment of the present invention. 図１において、燃料浮き上がり防止部材を取り外した状態における炉心の部分平面図である。FIG. 2 is a partial plan view of the core in a state where a fuel floating prevention member is removed in FIG. 1. 本発明の一実施形態に係る沸騰水型原子炉の縦断面図である。1 is a longitudinal sectional view of a boiling water reactor according to an embodiment of the present invention. 図３に示す沸騰水型原子炉の炉心に装荷される燃料集合体の縦断面図である。FIG. 4 is a longitudinal sectional view of a fuel assembly loaded in the core of the boiling water reactor shown in FIG. 3. 稠密に配された燃料集合体と制御棒との配置関係を示す炉心の部分平面図である。FIG. 3 is a partial plan view of a core showing a positional relationship between densely arranged fuel assemblies and control rods. 図２のＡ−Ａ断面矢視図であって、３体の燃料集合体の上部の部分側面図である。FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and is a partial side view of the upper part of three fuel assemblies. 図１に示す燃料浮き上がり防止部材の部分平面図である。FIG. 2 is a partial plan view of a fuel floating prevention member shown in FIG. 1. 図１に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＢ―Ｂ断面矢視図である。FIG. 2 is a partial plan view showing a positional relationship between a lattice member and a handle constituting the fuel floating prevention member shown in FIG. 図１に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＣ―Ｃ断面矢視図である。FIG. 2 is a partial plan view showing a positional relationship between a lattice member and a handle constituting the fuel floating prevention member shown in FIG. 1, and a CC cross-sectional arrow view thereof. シュラウドヘッドの近傍であって、図１に示す燃料浮き上がり防止部材を設置した状態を示す図である。FIG. 2 is a view showing a state where a fuel floating prevention member shown in FIG. 1 is installed in the vicinity of the shroud head. 本発明の他の実施例に係る実施例２の燃料浮き上がり防止部材の部分平面図と、そのＤ−Ｄ断面矢視図である。It is the fragmentary top view of the fuel floating prevention member of Example 2 which concerns on the other Example of this invention, and its DD sectional arrow directional view. 図１１に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＥ―Ｅ断面矢視図である。FIG. 12 is a partial plan view showing a positional relationship between a lattice member and a handle constituting the fuel floating prevention member shown in FIG. 11, and an EE cross-sectional arrow view thereof. 図１１に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＦ―Ｆ断面矢視図である。FIG. 12 is a partial plan view showing a positional relationship between a grid member and a handle constituting the fuel floating prevention member shown in FIG. 本発明の他の実施例に係る実施例３の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。FIG. 9 is a partial plan view of a core showing a positional relationship between a fuel floating prevention member and a fuel assembly according to a third embodiment of the present invention. 図１４のＧ−Ｇ断面矢視図であって、燃料浮き上がり防止部材３と燃料集合体の上部との位置関係を示す図である。FIG. 15 is a cross-sectional view taken along the line GG in FIG. 14, showing a positional relationship between the fuel floating prevention member 3 and the upper part of the fuel assembly. 本発明の他の実施例に係る実施例４の燃料浮き上がり防止部材の部分平面図と、そのＨ―Ｈ断面矢視図及びＩ―Ｉ断面矢視図である。It is the fragmentary top view of the fuel floating prevention member of Example 4 which concerns on the other Example of this invention, its HH cross-sectional arrow view, and II cross-sectional arrow view. 本発明の他の実施例に係る実施例５の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。FIG. 10 is a partial plan view of a reactor core showing a positional relationship between a fuel floating prevention member and a fuel assembly according to a fifth embodiment of the present invention. 図１７に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＪ―Ｊ断面矢視図である。FIG. 18 is a partial plan view showing a positional relationship between a lattice member and a handle constituting the fuel floating prevention member shown in FIG. 17, and a JJ cross-sectional arrow view thereof. 図１７に示す燃料浮き上がり防止部材を構成する格子部材とハンドルとの位置関係を示す部分平面図と、そのＫ―Ｋ断面矢視図である。FIG. 18 is a partial plan view showing a positional relationship between a lattice member and a handle constituting the fuel floating prevention member shown in FIG. 17, and a KK cross-sectional arrow view thereof. 本発明の他の実施例に係る実施例６の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。It is a fragmentary top view of the core which shows the arrangement | positioning relationship with the fuel floating prevention member and fuel assembly of Example 6 which concerns on the other Example of this invention.

先ず、図３に本発明の一実施形態に係る沸騰水型原子炉の縦断面図を示す。図３では、資源再利用型沸騰水型原子炉（Ｒｅｓｏｕｒｃｅ−Ｒｅｎｅｗａｂｌｅ Ｂｏｉｌｉｎｇ Ｗａｔｅｒ Ｒｅａｃｔｏｒ：ＲＢＷＲ）を一例として示すが、これに限られるものでは無い。例えば、改良型沸騰水型原子炉（Ａｄｖａｎｃｅｄ Ｂｏｉｌｉｎｇ Ｗａｔｅｒ Ｒｅａｃｔｏｒ：ＡＢＷＲ）、再循環ポンプを備え減速材としての冷却水を原子炉圧力容器外へ通流し再び原子炉圧力容器内のダウンカマへ流入させることで冷却水を循環させる通常の沸騰水型原子炉（ＢＷＲ）、或は、チムニによる冷却水の自然循環方式を用いることで、ＢＷＲにおける再循環ポンプ、ＡＢＷＲにおけるインターナルポンプを不要とする高経済性単純化沸騰水型原子炉（Ｅｃｏｎｏｍｉｃ Ｓｉｍｐｌｉｆｉｅｄ Ｂｏｉｌｉｎｇ Ｗａｔｅｒ Ｒｅａｃｔｏｒ：ＥＳＢＷＲ）等、その他の原子炉へも同様に適用可能である。すなわち、沸騰水型原子炉であれば、いずれの構成においても以下に説明する本発明の構成を適用可能である。   First, FIG. 3 shows a longitudinal sectional view of a boiling water reactor according to an embodiment of the present invention. Although FIG. 3 shows a resource-recyclable boiling water reactor (RBWR) as an example, the present invention is not limited to this. For example, an improved boiling water reactor (ABWR) equipped with a recirculation pump, cooling water as a moderator is passed outside the reactor pressure vessel, and again flows into the downcomer inside the reactor pressure vessel. By using a normal boiling water reactor (BWR) that circulates cooling water in the tank, or a natural circulation method of cooling water using chimney, a recirculation pump in BWR and an internal pump in ABWR are unnecessary. The present invention can be similarly applied to other nuclear reactors such as an electronically simplified boiling water reactor (ESBWR). That is, the configuration of the present invention described below can be applied to any configuration as long as it is a boiling water reactor.

図３に示すように、資源再利用型沸騰水型原子炉（ＲＢＷＲ）は、原子炉圧力容器２０内に円筒状の炉心シュラウド２４が設けられ、炉心シュラウド２４内に、複数体の燃料集合体が装荷された炉心２１が配設されている。また、円筒状の炉心シュラウド２４の軸方向上端部はシュラウドヘッド２５で覆われており、このシュラウドヘッド２５上部に上方へと延伸する気水分離器２７及び、気水分離器２７の上方に配される蒸気乾燥器２８が設けられている。原子炉圧力容器２０と炉心シュラウド２４の間には円環状のダウンカマ２６が形成されている。ダウンカマ２６内には、インターナルポンプ１４が配設されている。   As shown in FIG. 3, the resource reuse boiling water reactor (RBWR) includes a cylindrical core shroud 24 provided in a reactor pressure vessel 20, and a plurality of fuel assemblies are provided in the core shroud 24. A core 21 loaded with is disposed. Further, the axial upper end of the cylindrical core shroud 24 is covered with a shroud head 25, and the steam / water separator 27 extending upward on the shroud head 25 and the steam / water separator 27 are arranged above the steam / water separator 27. A steam dryer 28 is provided. An annular downcomer 26 is formed between the reactor pressure vessel 20 and the core shroud 24. An internal pump 14 is disposed in the downcomer 26.

インターナルポンプ１４から吐出された冷却水は、下部プレナム３０を経て炉心２１に供給される。冷却水は、炉心２１を通過する際に加熱されて水及び蒸気を含む気液二相流となる。気水分離器２７は気液二相流を蒸気と水に分離する。分離された蒸気は、更に蒸気乾燥器２８で湿分が除去されて主蒸気配管２９ａに導かれる。この湿分が除去された蒸気は、蒸気タービン（図示せず）に導かれ、蒸気タービンを回転させる。蒸気タービンに連結された発電機が回転し、電力を発生する。蒸気タービンから排出された蒸気は、復水器（図示せず）で凝縮されて水となる。この凝縮水は、冷却水として給水配管２９ｂにより原子炉圧力容器２０内に供給される。気水分離器２７及び蒸気乾燥器２８で分離された水は、落下して冷却水としてダウンカマ２６内に達する。   Cooling water discharged from the internal pump 14 is supplied to the core 21 through the lower plenum 30. The cooling water is heated when passing through the core 21 and becomes a gas-liquid two-phase flow containing water and steam. The steam separator 27 separates the gas-liquid two-phase flow into steam and water. The separated steam is further dehumidified by the steam dryer 28 and guided to the main steam pipe 29a. The steam from which the moisture has been removed is guided to a steam turbine (not shown) to rotate the steam turbine. A generator connected to the steam turbine rotates to generate electric power. The steam discharged from the steam turbine is condensed into water by a condenser (not shown). The condensed water is supplied as cooling water into the reactor pressure vessel 20 through the water supply pipe 29b. The water separated by the steam separator 27 and the steam dryer 28 falls and reaches the downcomer 26 as cooling water.

なお、原子炉圧力容器２０の下部プレナム３０には、燃料集合体の核反応を制御するため、炉心２１へ複数の水平断面（横断面）がＹ字型の制御棒を挿入可能とする制御棒案内管が設けられ、原子炉圧力容器２０の底部よりも下方に設置された制御棒駆動機構ハウジング内に制御棒駆動機構を備え、制御棒は制御棒駆動機構に連結されている。ここで、水平断面（横断面）がＹ字型の制御棒は、中心に位置するタイロッド（またはセンタポスト）から外側に向かって延伸する３枚の翼を備え、各翼は中性子吸収材であるＢ４Ｃが充填された複数の中性子吸収棒を有する。これら３枚の翼は、タイロッド（またはセンタポスト）の周囲に相互に１２０度の間隔にて配されている。そして、炉心２１に三角格子状に稠密に装荷される複数体の燃料集合体のうち、相互に隣接する３体の燃料集合体の間に、水平断面（横断面）がＹ字型の制御棒が１本挿入される。 In the lower plenum 30 of the reactor pressure vessel 20, a control rod in which a plurality of horizontal cross-sections (cross-sections) Y-shaped control rods can be inserted into the core 21 in order to control the nuclear reaction of the fuel assembly. A guide rod is provided, and a control rod drive mechanism is provided in a control rod drive mechanism housing installed below the bottom of the reactor pressure vessel 20, and the control rod is connected to the control rod drive mechanism. Here, the horizontal cross section (cross section) Y-shaped control rod includes three blades extending outward from a tie rod (or center post) located at the center, and each blade is a neutron absorber. It has a plurality of neutron absorber bars filled with B 4 C. These three blades are arranged at intervals of 120 degrees around the tie rod (or center post). A control rod having a Y-shaped horizontal cross section (cross section) between the three fuel assemblies adjacent to each other among the plurality of fuel assemblies densely loaded into the core 21 in a triangular lattice shape. Is inserted.

炉心２１は、炉心支持板２２に支持され、炉心２１内には複数体の燃料集合体、例えば、約７００体の燃料集合体が装荷されている。また、図３に示すように燃料集合体の上部に設けられるハンドルの上方に、燃料集合体の上方への浮き上がりを抑制するための燃料浮き上がり防止部材３１が設けられている。   The core 21 is supported by a core support plate 22, and a plurality of fuel assemblies, for example, about 700 fuel assemblies are loaded in the core 21. Further, as shown in FIG. 3, a fuel lift prevention member 31 is provided above a handle provided at the upper portion of the fuel assembly to prevent the fuel assembly from lifting upward.

図４は、図３に示す資源再利用型沸騰水型原子炉（ＲＢＷＲ）の炉心に装荷される燃料集合体の縦断面図である。図４に示すように、燃料集合体１は、複数の燃料棒２、上部タイプレート３、下部タイプレート４、複数の燃料スペーサ６、チャンネルボックス５、及びハンドル７を備えている。ハンドル７は、燃料集合体１の炉心２１への装荷又は燃料集合体１の交換時にクレーン等により把持するために設けられている。また、燃料棒２は、複数の燃料ペレット（図示せず）を、密封された被覆管（図示せず）内に充填している。下部タイプレート４は各燃料棒２の下端部を支持し、上部タイプレート３は各燃料棒２の上端部を保持する。燃料集合体１の下部は、炉心支持板２２を貫通するよう配される燃料支持金具８に設けられた３つの上部開口部９に、燃料集合体１を構成する下部タイプレート４の下部が嵌合し支持される。燃料支持金具８の中央には、水平断面（横断面）がＹ字型の制御棒を上下に移動できるように制御棒移動用開口部１０が設けられている。   FIG. 4 is a longitudinal sectional view of the fuel assembly loaded in the core of the resource reuse boiling water reactor (RBWR) shown in FIG. As shown in FIG. 4, the fuel assembly 1 includes a plurality of fuel rods 2, an upper tie plate 3, a lower tie plate 4, a plurality of fuel spacers 6, a channel box 5, and a handle 7. The handle 7 is provided to be gripped by a crane or the like when the fuel assembly 1 is loaded into the core 21 or the fuel assembly 1 is replaced. Further, the fuel rod 2 is filled with a plurality of fuel pellets (not shown) in a sealed cladding tube (not shown). The lower tie plate 4 supports the lower end of each fuel rod 2, and the upper tie plate 3 holds the upper end of each fuel rod 2. The lower portion of the lower tie plate 4 constituting the fuel assembly 1 is fitted to the lower portion of the fuel assembly 1 in the three upper openings 9 provided in the fuel support fitting 8 arranged so as to penetrate the core support plate 22. It is supported. A control rod moving opening 10 is provided at the center of the fuel support fitting 8 so that a control rod having a Y-shaped horizontal cross section (transverse cross section) can be moved up and down.

図４に示すように、燃料集合体１の上部に設けられるハンドル７の上面と、ハンドル７の上方に配される格子部材３２との間に弾性体３３が配されている。換言すれば、ハンドル７の上面の一部は、弾性体３３を介して格子部材３２の下面に接している。これにより、仮に、燃料集合体１が軸方向上方へと浮き上がるよう変位した場合であっても、弾性体３３及び格子部材３２により、上記浮き上がりの変位は抑制される。すなわち、燃料集合体１の浮き上がりが防止される。なお、弾性体３３が燃料集合体１の上部に設けられるハンドル７の上面と格子部材３２の下面との間に介在することで、格子部材３２及び／又はハンドル７を有する燃料集合体１の損傷を回避でき、良好に燃料集合体１の浮き上がりを防止することができる。
弾性体３３の軸方向上端面が、格子部材３２の下面に固定され燃料浮き上がり防止部材３１が構成される。この場合、燃料浮き上がり防止部材３１を構成する弾性体３３の軸方向下端面（弾性体３３の格子部材３２の下面とは反対側の面）は、燃料集合体１を構成するハンドル７に固定されることなく、当接している。なお、この構成に代えて、弾性体３３の軸方向下端面を、燃料集合体１を構成するハンドル７の上面の一部に固定する構成としても良い。この場合、ハンドル７の上面の一部に固定された弾性体３３と、格子部材３２とが協働することで燃料浮き上がり防止部材３１を構成することになる。このように、本実施形態の資源再利用型沸騰水型原子炉（ＲＢＷＲ）の炉心では、燃料浮き上がり防止部材３１を備えることにより、上記特許文献１に開示される、上部格子板、及び、上部格子板と上部タイプレートを接続するための上部支持機構が不要となる。 As shown in FIG. 4, an elastic body 33 is disposed between the upper surface of the handle 7 provided on the upper portion of the fuel assembly 1 and a lattice member 32 disposed above the handle 7. In other words, a part of the upper surface of the handle 7 is in contact with the lower surface of the lattice member 32 via the elastic body 33. Thus, even if the fuel assembly 1 is displaced so as to float upward in the axial direction, the elastic body 33 and the lattice member 32 suppress the above-described displacement of the lift. That is, the fuel assembly 1 is prevented from floating. The elastic body 33 is interposed between the upper surface of the handle 7 provided on the upper portion of the fuel assembly 1 and the lower surface of the lattice member 32, so that the fuel assembly 1 having the lattice member 32 and / or the handle 7 is damaged. The fuel assembly 1 can be satisfactorily prevented from floating.
The upper end surface in the axial direction of the elastic body 33 is fixed to the lower surface of the lattice member 32 to constitute the fuel floating prevention member 31. In this case, the lower end surface in the axial direction of the elastic body 33 constituting the fuel floating prevention member 31 (the surface opposite to the lower surface of the lattice member 32 of the elastic body 33) is fixed to the handle 7 constituting the fuel assembly 1. Without contact. Instead of this configuration, the lower end surface in the axial direction of the elastic body 33 may be fixed to a part of the upper surface of the handle 7 constituting the fuel assembly 1. In this case, the elastic body 33 fixed to a part of the upper surface of the handle 7 and the lattice member 32 cooperate to constitute the fuel floating prevention member 31. As described above, the core of the resource reuse boiling water reactor (RBWR) according to the present embodiment includes the upper lattice plate and the upper portion disclosed in Patent Document 1 by including the fuel floating prevention member 31. An upper support mechanism for connecting the lattice plate and the upper tie plate becomes unnecessary.

図５は、稠密に配された燃料集合体１と制御棒１１との配置関係を示す炉心２１の部分平面図である。図５に示すように、各燃料集合体１は、水平断面（横断面）が六角形状のチャンネルボックス５内に複数本の燃料棒を三角格子状に束ねて稠密に配している。また、相互に隣接して三角格子状に配される３体の燃料集合体の間に、水平断面（横断面）がＹ字型の制御棒１１が配されている。資源再利用型沸騰水型原子炉（ＲＢＷＲ）は、このように複数体の燃料集合体１を炉心２１に稠密に装荷することで、水対燃料体積比を低減した沸騰水型原子炉（ＢＷＲ）である。資源再利用型沸騰水型原子炉（ＲＢＷＲ）は、従来の沸騰水型原子炉（ＢＷＲ）と比較してプルトニウム増殖比を高めており、原子炉運転時における核***性プルトニウムの発生量と消費量をほぼ同一にでき、増殖比を約１．０とすることが可能である。   FIG. 5 is a partial plan view of the core 21 showing the arrangement relationship between the densely arranged fuel assemblies 1 and the control rods 11. As shown in FIG. 5, each fuel assembly 1 is densely arranged by bundling a plurality of fuel rods in a triangular lattice shape in a channel box 5 having a hexagonal horizontal section (transverse section). Further, a control rod 11 having a horizontal cross section (transverse cross section) having a Y-shape is arranged between three fuel assemblies arranged adjacent to each other in a triangular lattice shape. In the resource reusable boiling water reactor (RBWR), a plurality of fuel assemblies 1 are densely loaded into the core 21 in this way, thereby reducing the water-to-fuel volume ratio (BWR). ). Resource-recycling boiling water reactors (RBWR) have a higher plutonium breeding ratio than conventional boiling water reactors (BWR), and the generation and consumption of fissile plutonium during reactor operation. Can be made substantially the same, and the growth ratio can be about 1.0.

ここで、原子炉は、燃料集合体１内の燃料の核***により運転されているが、運転時間の経過と共に核***を行うウラン−２３５の割合が少なくなるため、計画的に燃料を新しいものに交換する必要がある。燃料交換時には原子炉臨界防止のため、水平断面（横断面）がＹ字型の制御棒１１を挿入する必要があり、燃料交換時には、水平断面（横断面）がＹ字型の制御棒１１、及び水平断面（横断面）がＹ字型の制御棒と隣接する３体の燃料集合体１の組み合わせで燃料交換することが合理的である。上述のように燃料集合体１の上部には、燃料集合体移動用にハンドル７が設けられており、原子炉運転時におけるハンドル７の配置を変更することなく、燃料交換を実施できるようにすることが望ましい。   Here, the nuclear reactor is operated by fission of the fuel in the fuel assembly 1, but the proportion of uranium-235 that undergoes fission decreases as the operating time elapses, so the fuel is systematically replaced with a new one. There is a need to. It is necessary to insert a control rod 11 having a horizontal cross section (cross section) in order to prevent the criticality of the reactor when the fuel is changed. In addition, it is reasonable to replace the fuel with a combination of the three fuel assemblies 1 adjacent to the Y-shaped control rod in the horizontal section (cross section). As described above, the handle 7 is provided at the upper part of the fuel assembly 1 for moving the fuel assembly, so that fuel replacement can be performed without changing the arrangement of the handle 7 during the operation of the nuclear reactor. It is desirable.

また、水平断面（横断面）が四角形状のチャンネルボックス内に複数の燃料棒を正方格子状に配すると共に、複数体の燃料集合体を炉心に正方格子状に装荷する従来の沸騰水型原子炉に対して、資源再利用型沸騰水型原子炉（ＲＢＷＲ）では、燃料集合体一体当たりの燃料棒の本数を増大できる。しかしながら、燃料棒一本当たりの重量が軽くなるため、燃料集合体全体では、従来の沸騰水型原子炉と比較して重量は軽くなる。また、資源再利用型沸騰水型原子炉（ＲＢＷＲ）では、燃料集合体１内に三角格子状に稠密に配される燃料棒の被覆管の管径が小さくなる。そのため、仮に、従来の沸騰水型原子炉と同様の間隔にて軸方向に離間し燃料スペーサ６を配し、燃料棒を支持する構成とした場合、燃料スペーサ６による支持部間の中央の燃料棒２の水平方向の変位量が大きくなり、他の燃料棒２と接触する事態が生じることが予想される。そこで、上述の図４に示したように、従来の沸騰水型原子炉の場合と比較して、燃料スペーサ６の軸方向の設置間隔を狭くしている。燃料スペーサ６の設置間隔を狭くすることは、燃料スペーサ６の設置個数が増えることを意味し、燃料集合体１内を上方へと通流する冷却水に対する圧損が増大し、燃料集合体１を軸方向上方へと浮き上がらせるよう作用する流体力も同時に増大する。仮に、燃料集合体１が軸方向上方へと浮き上がると、燃料支持金具８の挿し込み部から下部タイプレート４が離脱し、他の構造物に接触し、燃料集合体１の損傷に至る可能性が懸念される。そのため、図３及び図４に示したように、燃料集合体１の軸方向上方に燃料浮き上がり防止部材３１を備えることに技術的意義を有するのである。以下では、格子部材３２及び弾性体３３にて燃料浮き上がり防止部材３１を構成する場合を一例として説明するが、これに限られず、燃料浮き上がり防止部材３１を格子部材３２のみで構成し、この燃料浮き上がり防止部材３１と燃料集合体１のハンドル７の上面との間に、弾性体３３を配する構成としても良いことは言うまでもない。
以下、図面を用いて本発明の実施例について、燃料浮き上がり防止部材３１を中心に詳細説明する。 Also, a conventional boiling water atom in which a plurality of fuel rods are arranged in a square lattice in a channel box having a rectangular horizontal cross section (transverse cross section), and a plurality of fuel assemblies are loaded in a square lattice in the core. In contrast to a reactor, in a resource reusable boiling water reactor (RBWR), the number of fuel rods per fuel assembly can be increased. However, since the weight per fuel rod is reduced, the weight of the entire fuel assembly is reduced as compared with a conventional boiling water reactor. Further, in the resource reusable boiling water reactor (RBWR), the diameter of the cladding tube of the fuel rods densely arranged in a triangular lattice shape in the fuel assembly 1 is reduced. For this reason, if the fuel spacer 6 is arranged to be spaced apart in the axial direction at the same interval as in the conventional boiling water reactor and the fuel rod is supported, the fuel in the center between the support portions by the fuel spacer 6 is assumed. It is expected that the amount of displacement of the rod 2 in the horizontal direction will increase and a situation where it comes into contact with another fuel rod 2 will occur. Therefore, as shown in FIG. 4 described above, the installation interval in the axial direction of the fuel spacer 6 is made narrower than in the case of the conventional boiling water reactor. Narrowing the installation interval of the fuel spacers 6 means that the number of installation of the fuel spacers 6 is increased, and the pressure loss with respect to the cooling water flowing upward in the fuel assembly 1 is increased. The fluid force acting to lift upward in the axial direction also increases at the same time. If the fuel assembly 1 is lifted upward in the axial direction, the lower tie plate 4 may be detached from the insertion portion of the fuel support fitting 8 and come into contact with other structures, leading to damage to the fuel assembly 1. Is concerned. Therefore, as shown in FIG. 3 and FIG. 4, it has technical significance in providing the fuel floating prevention member 31 at the upper side in the axial direction of the fuel assembly 1. In the following, the case where the fuel floating prevention member 31 is configured by the lattice member 32 and the elastic body 33 will be described as an example. However, the present invention is not limited to this. It goes without saying that an elastic body 33 may be arranged between the prevention member 31 and the upper surface of the handle 7 of the fuel assembly 1.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, focusing on the fuel floating prevention member 31.

図１は、本発明の一実施例に係る実施例１の燃料浮き上がり防止部材３１及び燃料集合体１との配置関係を示す炉心の部分平面図であり、図２は、図１において、燃料浮き上がり防止部材３１を取り外した状態における炉心の部分平面図である。上述したように、資源再利用型沸騰水型原子炉（ＲＢＷＲ）では、炉心２１（図３）に、例えば、約７００体の燃料集合体１が装荷さている。図１及び図２では、炉心２１に装荷される複数体の燃料集合体１のうち１０体の燃料集合体１と、相互に離接して配される３体の燃料集合体（例えば、燃料集合体１ａ〜１ｃ）の間に配置される水平断面（横断面）がＹ字型の制御棒１１（図１では点線で示す）を一例として示す。図５に示したように、各燃料集合体１は、水平断面（横断面）が六角形状のチャンネルボックス５内に複数本の燃料棒を三角格子状に束ねて稠密に配している。また、相互に隣接して三角格子状に配される３体の燃料集合体の間に、水平断面（横断面）がＹ字型の制御棒１１が配されている。水平断面（横断面）がＹ字型の制御棒１１は、相互に１２０度の間隔にて配される３枚の翼を備える。   FIG. 1 is a partial plan view of a core showing a positional relationship between a fuel floating prevention member 31 and a fuel assembly 1 according to a first embodiment of the present invention. FIG. 2 is a partial plan view of a core in a state where a prevention member 31 is removed. FIG. As described above, in the resource reusable boiling water reactor (RBWR), for example, about 700 fuel assemblies 1 are loaded in the core 21 (FIG. 3). 1 and 2, ten fuel assemblies 1 among a plurality of fuel assemblies 1 loaded in the core 21 and three fuel assemblies (for example, fuel assemblies) arranged in contact with each other are separated. As an example, a control rod 11 (shown by a dotted line in FIG. 1) having a Y-shaped horizontal section (transverse section) disposed between the bodies 1a to 1c) is shown. As shown in FIG. 5, each fuel assembly 1 is densely arranged by bundling a plurality of fuel rods in a triangular lattice shape in a channel box 5 having a hexagonal horizontal section (transverse section). Further, a control rod 11 having a horizontal cross section (transverse cross section) having a Y-shape is arranged between three fuel assemblies arranged adjacent to each other in a triangular lattice shape. The control rod 11 whose horizontal cross section (transverse cross section) is Y-shaped includes three wings arranged at intervals of 120 degrees.

図１に示すように、複数体の燃料集合体１の上方に配される燃料浮き上がり防止部材３１を構成する格子部材３２は、三角格子が二次元的に連なる形状を有する。換言すれば、燃料浮き上がり防止部材３１を構成する格子部材３２は、三角格子の繰り返しパターン形状を備える。例えば、格子部材３２ａは、燃料集合体１ａを構成するハンドル７ａ上面の長辺７１ａと交差し、格子部材３２ｂは、燃料集合体１ｂを構成するハンドル７ｂ上面の長辺７１ｂと交差し、格子部材３２ｃは、燃料集合体１ｃを構成するハンドル７ｃ上面の長辺７１ｃと交差するよう、格子部材３２が配されている。これら、相互に隣接して三角格子状に配される３体の燃料集合体である、燃料集合体１ａ、燃料集合体１ｂ、及び燃料集合体１ｃの間には、水平断面（横断面）がＹ字型の制御棒１１が配され、格子部材３２ａ、格子部材３２ｂ、及び格子部材３２ｃの接続部は、水平断面（横断面）がＹ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）（図示せず）のほぼ直上に位置している。また、格子部材３２ａはハンドル７ａ上面の長辺７１ａ（ハンドル７ａの長手方向に沿った両側面を画定する辺）と略直交するよう交差し、その交差する位置は、長辺７１ａの略中央部である。同様に、格子部材３２ｂはハンドル７ｂ上面の長辺７１ｂ（ハンドル７ｂの長手方向に沿った両側面を画定する辺）と略直交するよう交差し、その交差する位置は、長辺７１ｂの略中央部である。また、格子部材３２ｃはハンドル７ｃ上面の長辺７１ｃ（ハンドル７ｃの長手方向に沿った両側面を画定する辺）と略直交するよう交差し、その交差する位置は、長辺７１ｃの略中央部である。   As shown in FIG. 1, the lattice member 32 constituting the fuel floating prevention member 31 disposed above the plurality of fuel assemblies 1 has a shape in which triangular lattices are two-dimensionally connected. In other words, the lattice member 32 constituting the fuel floating prevention member 31 has a repeated pattern shape of a triangular lattice. For example, the lattice member 32a intersects with the long side 71a on the upper surface of the handle 7a constituting the fuel assembly 1a, and the lattice member 32b intersects with the long side 71b on the upper surface of the handle 7b constituting the fuel assembly 1b. The lattice member 32 is arranged so that 32c may cross | intersect the long side 71c of the upper surface of the handle 7c which comprises the fuel assembly 1c. Between these fuel assemblies 1a, 1b, and 1c, which are three fuel assemblies arranged adjacent to each other in a triangular lattice shape, there is a horizontal cross section (cross section). A Y-shaped control rod 11 is arranged, and a connecting portion of the lattice member 32a, the lattice member 32b, and the lattice member 32c is a tie rod (or center) whose horizontal section (transverse section) is the center of the Y-shaped control rod 11. It is located almost immediately above the post (not shown). The lattice member 32a intersects with the long side 71a of the upper surface of the handle 7a (side defining both side surfaces along the longitudinal direction of the handle 7a) so as to be substantially orthogonal, and the intersecting position is a substantially central portion of the long side 71a. It is. Similarly, the lattice member 32b intersects with a long side 71b (side defining both side surfaces along the longitudinal direction of the handle 7b) of the upper surface of the handle 7b so as to be substantially orthogonal, and the intersecting position is substantially the center of the long side 71b. Part. The lattice member 32c intersects the long side 71c (the side defining both side surfaces along the longitudinal direction of the handle 7c) on the upper surface of the handle 7c so as to be substantially orthogonal, and the intersecting position is a substantially central portion of the long side 71c. It is.

上述の関係は、他の相互に隣接して三角格子状に配される３体の燃料集合体１と、これら３体の燃料集合体１の上方に配される格子部材３２についても同様である。このように、燃料浮き上がり防止部材３１を構成する格子部材３２を、燃料集合体１を構成するハンドル７の長辺と交差するよう配することで、各燃料集合体１の上方の冷却水（冷却材）の流路を格子部材３２により大きく塞ぐことなく、広い面積の冷却水（冷却材）の流路を確保することが可能となる。また、燃料集合体１内を上方へと通流する冷却水に対する圧損の増加を抑制することも可能となる。   The above-described relationship is the same for the three fuel assemblies 1 arranged in a triangular lattice shape adjacent to each other and the lattice members 32 arranged above the three fuel assemblies 1. . As described above, the lattice member 32 constituting the fuel floating prevention member 31 is arranged so as to intersect with the long side of the handle 7 constituting the fuel assembly 1, so that the cooling water (cooling) above each fuel assembly 1 is cooled. It is possible to secure a flow path for cooling water (cooling material) having a large area without greatly closing the flow path of the material. It is also possible to suppress an increase in pressure loss with respect to the cooling water flowing upward in the fuel assembly 1.

また、図２に示すように、燃料集合体１ａを構成するハンドル７ａ上面の長辺７１ａ、燃料集合体１ｂを構成するハンドル７ｂ上面の長辺７１ｂ、及び、燃料集合体１ｃを構成するハンドル７ｃ上面の長辺７１ｃは、水平断面（横断面）がＹ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）（図示せず）に向かうよう、３体の燃料集合体１ａ〜１ｃが炉心２１に装荷されている。このような配置関係は、相互に隣接して三角格子状に配される他の３体の燃料集合体と、これら３体の燃料集合体１間に水平断面（横断面）がＹ字型の制御棒１１が配される場合においても同様である。このように、水平断面（横断面）がＹ字型の制御棒１１を囲むよう、相互に隣接して三角格子状に稠密に配される３体の燃料集合体１ａ〜１ｃのハンドル７ａ〜７ｃ上面の長辺７１ａ〜７１ｃの全てが、水平断面（横断面）がＹ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）に向くよう配されることから、原子炉運転時におけるハンドル７ａ〜７ｃの配置を変更することなく、定期検査或いは燃料交換等を実施でき、作業性を向上することが可能となる。   Further, as shown in FIG. 2, the long side 71a on the upper surface of the handle 7a constituting the fuel assembly 1a, the long side 71b on the upper surface of the handle 7b constituting the fuel assembly 1b, and the handle 7c constituting the fuel assembly 1c. The long side 71c of the upper surface has three fuel assemblies 1a to 1c such that the horizontal cross section (transverse cross section) faces a tie rod (or center post) (not shown) that is the center of the Y-shaped control rod 11. The core 21 is loaded. Such an arrangement relationship is that the other three fuel assemblies arranged adjacent to each other in the form of a triangular lattice and the horizontal cross section (transverse section) between these three fuel assemblies 1 are Y-shaped. The same applies to the case where the control rod 11 is arranged. As described above, the handles 7a to 7c of the three fuel assemblies 1a to 1c that are densely arranged adjacent to each other in a triangular lattice so that the horizontal cross section (transverse cross section) surrounds the Y-shaped control rod 11 are arranged. Since all of the long sides 71a to 71c on the upper surface are arranged so that the horizontal cross section (transverse cross section) faces the tie rod (or center post) that is the center of the Y-shaped control rod 11, the handle during operation of the reactor Periodic inspection or fuel replacement can be performed without changing the arrangement of 7a to 7c, and workability can be improved.

これに対し、図１及び図２に示されるように、燃料集合体１ａを構成するハンドル７ａ上面の短辺７２ａ（ハンドル７ａの長手方向の両端部を画定する辺）、燃料集合体１ｂを構成するハンドル７ｂ上面の短辺７２ｂ（ハンドル７ｂの長手方向の両端部を画定する辺）、及び、燃料集合体１ｃを構成するハンドル７ｃ上面の短辺７１ｃ（ハンドル７ｃの長手方向の両端部を画定する辺）は、いずれの格子部材３２と交差することなく、また、水平断面（横断面）がＹ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）（図示せず）に向かうことなく配される。これは、他の燃料集合体１を構成するハンドル７においても同様である。   On the other hand, as shown in FIG. 1 and FIG. 2, the short side 72a of the upper surface of the handle 7a constituting the fuel assembly 1a (the side defining both ends in the longitudinal direction of the handle 7a) and the fuel assembly 1b are configured. The short side 72b of the upper surface of the handle 7b (side defining the longitudinal ends of the handle 7b) and the short side 71c of the upper surface of the handle 7c constituting the fuel assembly 1c (defining both longitudinal ends of the handle 7c) Side) does not intersect any grid member 32 and is directed to a tie rod (or center post) (not shown) whose horizontal section (transverse section) is the center of the Y-shaped control rod 11. It is arranged without. The same applies to the handles 7 constituting the other fuel assemblies 1.

図６は、図２のＡ−Ａ断面矢視図であって、３体の燃料集合体１ａ〜１ｃの上部の部分側面図である。図６に示すように、３体の燃料集合体１ａ〜１ｃの上部には、燃料集合体をクレーンで吊って移動可能とするハンドル７ａ、７ｂ、７ｃがそれぞれ設けられている。また、各燃料集合体１ａ〜１ｃは、上述のとおり水平断面（横断面）が六角形状のチャンネルボックス５内に複数本の燃料棒を三角格子状に束ねて稠密に配する構成であることから、チャンネルボックス５は、軸方向に延伸する６面の側面を有する。これら、６面の側面のうち、水平断面（横断面）がＹ字型の制御棒１１を構成するタイロッド（またはセンタポスト）（図示せず）を中心とし相互に１２０の間隔にて配される３枚の翼のうち、２枚の翼と対向するチャンネルボックス５の２面の側面を除く、４面の側面の上端部付近には、それぞれ、燃料集合体接触防止パッド１３が設けられている。一方、上記２枚の翼と対向するチャンネルボックス５の２面の側面の上部付近には、それぞれ、制御棒接触防止パッド１２が設けられている。図６では、隣接して配される燃料集合体１ｂと燃料集合体１ｃとの間に、水平断面（横断面）がＹ字型の制御棒１１を構成する１枚の翼が配さている状態を示している。   6 is a cross-sectional view taken along the line AA of FIG. 2 and is a partial side view of the upper part of the three fuel assemblies 1a to 1c. As shown in FIG. 6, handles 7 a, 7 b, and 7 c are provided above the three fuel assemblies 1 a to 1 c so that the fuel assemblies can be suspended by a crane and moved. Further, each fuel assembly 1a to 1c has a configuration in which a plurality of fuel rods are bundled in a triangular lattice pattern in a hexagonal shape in a hexagonal channel box 5 as described above. The channel box 5 has six side surfaces extending in the axial direction. Of these six side surfaces, the horizontal cross section (transverse cross section) is arranged at 120 intervals from each other with a tie rod (or center post) (not shown) constituting the Y-shaped control rod 11 as the center. Fuel assembly contact prevention pads 13 are provided in the vicinity of the upper ends of the four side surfaces except the two side surfaces of the channel box 5 facing the two wings of the three wings. . On the other hand, control rod contact prevention pads 12 are provided in the vicinity of the upper portions of the two side surfaces of the channel box 5 facing the two wings. In FIG. 6, a state in which one blade constituting the control rod 11 having a horizontal cross section (transverse cross section) Y-shaped is arranged between the fuel assembly 1b and the fuel assembly 1c arranged adjacent to each other. Is shown.

図６では、水平断面（横断面）がＹ字型の制御棒１１が最上部まで挿入された状態を示している。また、図２に示したように、水平断面（横断面）がＹ字型の制御棒１１が挿入される側のチャンネルボックス５の側面以外の面は、隣接する他の燃料集合体１のチャンネルボックス５の側面との間に間隙を有するが、この間隙は、水平断面（横断面）がＹ字型の制御棒１１が挿入される隣接する２つの燃料集合体である、燃料集合体１ｂのチャンネルボックス５の側面と、燃料集合体１ｃのチャンネルボックス５の側面との間隙よりも明らかに狭い。従って、図６に示すように、制御棒接触防止パッド１２の厚さは、燃料集合体接触防止パッド１３の厚さよりも大きく、これら燃料集合体１ｂに設けられた制御棒接触防止パッド１２と燃料集合体１ｃに設けられた制御棒接触防止パッド１２とが当接することにより、水平断面（横断面）がＹ字型の制御棒１１の挿入路が確保される。   FIG. 6 shows a state in which the control rod 11 having a horizontal cross section (transverse cross section) having a Y-shape is inserted to the top. Further, as shown in FIG. 2, the surface other than the side surface of the channel box 5 on the side where the control rod 11 having a Y-shaped horizontal section (transverse section) is inserted is a channel of another adjacent fuel assembly 1. There is a gap between the side surfaces of the box 5, and this gap is a gap of the fuel assembly 1 b that is two adjacent fuel assemblies into which the control rod 11 having a Y-shaped horizontal section (transverse section) is inserted. It is clearly narrower than the gap between the side surface of the channel box 5 and the side surface of the channel box 5 of the fuel assembly 1c. Therefore, as shown in FIG. 6, the thickness of the control rod contact prevention pad 12 is larger than the thickness of the fuel assembly contact prevention pad 13, and the control rod contact prevention pad 12 provided on these fuel assemblies 1b and the fuel When the control rod contact prevention pad 12 provided on the assembly 1c comes into contact, an insertion path for the control rod 11 having a horizontal cross section (transverse cross section) is secured.

図７は、図１に示す燃料浮き上がり防止部材３１の部分平面図であり、図８は、図１に示す燃料浮き上がり防止部材３１を構成する格子部材３２とハンドル７との位置関係を示す部分平面図と、そのＢ―Ｂ断面矢視図、図９は、図１に示す燃料浮き上がり防止部材３１を構成する格子部材３２とハンドル７との位置関係を示す部分平面図と、そのＣ―Ｃ断面矢視図である。   7 is a partial plan view of the fuel floating prevention member 31 shown in FIG. 1, and FIG. 8 is a partial plan view showing the positional relationship between the lattice member 32 and the handle 7 constituting the fuel floating prevention member 31 shown in FIG. 9 is a partial plan view showing the positional relationship between the lattice member 32 and the handle 7 constituting the fuel floating prevention member 31 shown in FIG. 1, and its CC cross section. It is an arrow view.

図７に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２の平面形状は、格子部材３２ａ、格子部材３２ｂ、及び格子部材３２ｃを三角格子状に組み合わせたものであり、それぞれの格子部材３２ａ、格子部材３２ｂ、及び格子部材３２ｃは、上述したように各ハンドル７ａ、ハンドル７ｂ、及びハンドル７ｃの上方に配される。また、図１にて説明したように、格子部材３２ａをハンドル７ａ上面の長辺７１ａに、格子部材３２ｂをハンドル７ｂ上面の長辺７１ｂに、また、格子部材３２ｃをハンドル７ｃの長辺７１ｃに交差するよう、燃料浮き上がり防止部材３１を構成する格子部材３２を配することで、三角格子の繰り返しパターン形状を備える格子部材３２にて、容易且つ単純な構造にて燃料浮き上がり防止部材３１を実現できる。
なお、燃料浮き上がり防止部材３１を構成する格子部材３２、制御棒接触防止パッド１２、及び燃料集合体接触防止パッド１３は、例えば、ステンレス鋼製である。 As shown in FIG. 7, the planar shape of the lattice member 32 constituting the fuel floating prevention member 31 is a combination of the lattice member 32a, the lattice member 32b, and the lattice member 32c in a triangular lattice shape. 32a, the lattice member 32b, and the lattice member 32c are arranged above the handles 7a, 7b, and 7c as described above. Further, as described in FIG. 1, the lattice member 32a is on the long side 71a on the top surface of the handle 7a, the lattice member 32b is on the long side 71b on the top surface of the handle 7b, and the lattice member 32c is on the long side 71c of the handle 7c. By arranging the lattice members 32 constituting the fuel floating prevention member 31 so as to cross each other, the fuel floating prevention member 31 can be realized with an easy and simple structure with the lattice member 32 having a repeated pattern shape of a triangular lattice. .
Note that the lattice member 32, the control rod contact prevention pad 12, and the fuel assembly contact prevention pad 13 constituting the fuel floating prevention member 31 are made of, for example, stainless steel.

図８の上図は、図１に示した燃料集合体１ａと燃料浮き上がり防止部材３１を構成する格子部材３２ａとの配置関係において、時計回り又は反時計回りに９０度回転させた状態での部分平面図であり、図８の下図は、上図のＢ−Ｂ断面矢視図である。図８の上図に示すように、格子部材３２ａは、ハンドル７ａ上面の長辺と略直交するよう交差している。
また、図９の上図は、図１に示した燃料集合体１ａと燃料浮き上がり防止部材３１を構成する格子部材３２ａとの配置関係を示しており、図９の下図は、上図のＣ−Ｃ断面矢視図である。図８の下図及び図９の下図に示すように、弾性体３３の軸方向上端面が、格子部材３２ａの下面に固定され燃料浮き上がり防止部材３１が構成される。この場合、燃料浮き上がり防止部材３１を構成する弾性体３３の軸方向下端面（弾性体３３の格子部材３２ａの下面とは反対側の面）は、燃料集合体１ａを構成するハンドル７ａに固定されることなく、当接している。本実施例では、弾性体３３として、コイルばねを用いる場合を一例として示している。図９の下図に示すように、燃料集合体１ａを構成するハンドル７ａの上面の一部は、当接する弾性体３３としてのコイルばねにより付勢され、燃料集合体１ａは軸方向下方へと適度な押圧力により押圧されている。仮に、冷却水に対する圧損により燃料集合体１ａを軸方向上方へと浮き上がらせるよう流体力が作用した場合であっても、弾性体３３としてのコイルばねのばね力により、燃料浮き上がり防止部材３１及び／又は燃料集合体１ａが損傷することを防止できる。 The upper diagram of FIG. 8 shows a portion of the fuel assembly 1a shown in FIG. 1 and the lattice member 32a constituting the fuel floating prevention member 31 that is rotated 90 degrees clockwise or counterclockwise. It is a top view and the lower figure of FIG. 8 is a BB cross-sectional arrow view of the upper figure. As shown in the upper diagram of FIG. 8, the lattice member 32a intersects with the long side of the upper surface of the handle 7a so as to be substantially orthogonal.
9 shows the positional relationship between the fuel assembly 1a shown in FIG. 1 and the lattice member 32a constituting the fuel floating prevention member 31, and the lower figure in FIG. FIG. As shown in the lower diagram of FIG. 8 and the lower diagram of FIG. 9, the upper end surface in the axial direction of the elastic body 33 is fixed to the lower surface of the lattice member 32 a to constitute the fuel floating prevention member 31. In this case, the lower end surface in the axial direction of the elastic body 33 constituting the fuel floating prevention member 31 (the surface opposite to the lower surface of the lattice member 32a of the elastic body 33) is fixed to the handle 7a constituting the fuel assembly 1a. Without contact. In this embodiment, the case where a coil spring is used as the elastic body 33 is shown as an example. As shown in the lower part of FIG. 9, a part of the upper surface of the handle 7a constituting the fuel assembly 1a is urged by a coil spring as an elastic body 33 that abuts, so that the fuel assembly 1a is moderately lowered in the axial direction. It is pressed by a strong pressing force. Even if a fluid force acts to lift the fuel assembly 1a upward in the axial direction due to pressure loss with respect to the cooling water, the fuel lift prevention member 31 and / or the spring force of the coil spring as the elastic body 33 is applied. Or it can prevent that the fuel assembly 1a is damaged.

なお、弾性体３３として、コイルばねに限らず、板ばね或いは竹の子ばね等を用いても良い。また、図８及び図９では、弾性体３３として１つのコイルばねを用いる場合を一例として示しているが、設置する弾性体３３としてのコイルばねの個数はこれに限られるものではなく、複数個のコイルばねを設置する構成としてもよい。また、本実施例では、弾性体３３としてのコイルばねの一端（軸方向上端部）を格子部材３２ａの下面に固定する構成としたがこれに限られるものではない。例えば、弾性体３３としてのコイルばねの一端（軸方向下方端）を、燃料集合体１ａを構成するハンドル７ａの上面に固定し、コイルばねの他端を格子部材３２ａの下面に固定することなく、当接させる構成としても良い。但し、長期に渡り原子炉圧力容器２０内の冷却水（冷却材）に、弾性体３３としてのコイルばねが浸漬することを考慮すると、弾性体３３としてのコイルばねの一端をハンドル７ａの上面に固定し、燃料交換時等に燃料集合体１ａと共に弾性体３３としてのコイルばねも交換することが望ましい。   The elastic body 33 is not limited to a coil spring but may be a leaf spring or a bamboo spring. 8 and 9 show an example in which one coil spring is used as the elastic body 33. However, the number of coil springs as the elastic body 33 to be installed is not limited to this, and a plurality of coil springs are used. It is good also as a structure which installs this coil spring. In the present embodiment, one end (the upper end in the axial direction) of the coil spring as the elastic body 33 is fixed to the lower surface of the lattice member 32a. However, the present invention is not limited to this. For example, one end (a lower end in the axial direction) of the coil spring as the elastic body 33 is fixed to the upper surface of the handle 7a constituting the fuel assembly 1a, and the other end of the coil spring is not fixed to the lower surface of the lattice member 32a. It is good also as a structure made to contact | abut. However, considering that the coil spring as the elastic body 33 is immersed in the cooling water (coolant) in the reactor pressure vessel 20 over a long period of time, one end of the coil spring as the elastic body 33 is placed on the upper surface of the handle 7a. It is preferable to replace the coil spring as the elastic body 33 together with the fuel assembly 1a when the fuel is replaced.

図１０に、シュラウドヘッド２５の近傍であって、図１に示す燃料浮き上がり防止部材３１を設置した状態を示す。図１０は、原子炉圧力容器２０内の炉心２１の上部の側面図である。炉心２１は、三角格子状に稠密に配された燃料集合体１の最外周の側面、すなわち、最外周燃料集合体１の側面に、円環状（リング状）の炉心支持枠２３を有する。炉心支持枠２３の内側面（内周面）は、最外周燃料集合体１の形状（横断面が六角形状のチャンネルボックス５）と適合するよう凹凸を有する形状となっている。炉心支持枠２３の外側面（外周面）は、円筒形状の炉心シュラウド２４の内面（内周面）とほぼ同様の形状及び寸法を有している。炉心支持枠２３は、炉心シュラウド２４の内面（内周面）に設けた支持部（図示せず）に固定されている。図１０に示すように、燃料浮き上がり防止部材３１は、三角格子状に稠密に配された燃料集合体１を構成するハンドル７の上方に配されている。燃料浮き上がり防止部材３１の最外周部は、炉心支持枠２３にて支持されている。これにより、燃料浮き上がり防止部材３１は、炉心２１内において水平方向及び鉛直方向（軸方向）のいずれの方向に対しても固定されている。なお、本実施例では、燃料浮き上がり防止部材３１を炉心支持枠２３にて支持する構成を一例として示すが、この構成に限られるものではない。例えば、炉心シュラウド２４の内側面（内周面）に支持部材を設け、当該支持部材により、燃料浮き上がり防止部材３１の最外周部を固定する構成としても良い。   FIG. 10 shows a state where the fuel floating prevention member 31 shown in FIG. 1 is installed in the vicinity of the shroud head 25. FIG. 10 is a side view of the upper part of the core 21 in the reactor pressure vessel 20. The core 21 has an annular (ring-shaped) core support frame 23 on the outermost side surface of the fuel assembly 1 that is densely arranged in a triangular lattice pattern, that is, on the side surface of the outermost fuel assembly 1. The inner side surface (inner peripheral surface) of the core support frame 23 has a shape having irregularities so as to match the shape of the outermost peripheral fuel assembly 1 (channel box 5 having a hexagonal cross section). The outer surface (outer peripheral surface) of the core support frame 23 has substantially the same shape and dimensions as the inner surface (inner peripheral surface) of the cylindrical core shroud 24. The core support frame 23 is fixed to a support portion (not shown) provided on the inner surface (inner peripheral surface) of the core shroud 24. As shown in FIG. 10, the fuel floating prevention member 31 is disposed above the handle 7 constituting the fuel assembly 1 densely arranged in a triangular lattice shape. The outermost peripheral portion of the fuel floating prevention member 31 is supported by the core support frame 23. Thus, the fuel floating prevention member 31 is fixed in the horizontal direction and the vertical direction (axial direction) in the core 21. In the present embodiment, a configuration in which the fuel floating prevention member 31 is supported by the core support frame 23 is shown as an example, but the configuration is not limited thereto. For example, it is good also as a structure which provides a support member in the inner surface (inner peripheral surface) of the core shroud 24, and fixes the outermost peripheral part of the fuel floating prevention member 31 with the said support member.

本実施例によれば、運転時における燃料浮き上がりを防止しつつ、定期検査或は燃料交換等の作業効率を向上し得る沸騰水型原子炉の炉心を提供することが可能となる。
また、本実施例によれば、Ｙ字型の制御棒を囲むよう、相互に隣接して三角格子状に稠密に配される３体の燃料集合体のハンドル上面の長辺が、Ｙ字型の制御棒の中心に向かうよう配されることから、原子炉運転時におけるハンドルの配置を変更することなく、定期検査或いは燃料交換等を実施でき、作業性を向上することが可能となる。
更にまた、本実施例によれば、Ｙ字型の制御棒を囲むよう、相互に隣接して三角格子状に稠密に配される３体の燃料集合体のハンドル上面の長辺と交差するよう、三角格子の繰り返しパターン形状を備える格子部材を配することで、容易且つ単純な構造にて燃料浮き上がり防止部材を実現できる。
また、本実施例によれば、三角格子の繰り返しパターン形状を備える格子部材にばね等の弾性部材を配し燃料浮き上がり防止部材を構成することで、燃料集合体の軸方向上方への浮き上がりを好適に防止することが可能となる。 According to the present embodiment, it is possible to provide a boiling water reactor core that can improve the working efficiency of periodic inspection or fuel replacement while preventing the fuel from floating during operation.
Further, according to the present embodiment, the long sides of the upper surface of the handle of the three fuel assemblies that are densely arranged in a triangular lattice pattern adjacent to each other so as to surround the Y-shaped control rod are formed in the Y-shape. Therefore, the periodic inspection or the fuel change can be performed without changing the arrangement of the handles during the operation of the nuclear reactor, and the workability can be improved.
Furthermore, according to the present embodiment, the long side of the upper surface of the handle of the three fuel assemblies that are densely arranged in a triangular lattice pattern adjacent to each other so as to surround the Y-shaped control rods. By disposing a lattice member having a repetitive pattern shape of a triangular lattice, a fuel floating prevention member can be realized with an easy and simple structure.
Further, according to the present embodiment, the fuel member is prevented from being lifted in the axial direction by arranging the elastic member such as a spring on the lattice member having a repetitive pattern shape of the triangular lattice to constitute the fuel lift preventing member. Can be prevented.

図１１は、本発明の他の実施例に係る実施例２の燃料浮き上がり防止部材の部分平面図と、そのＤ−Ｄ断面矢視図である。本実施例では、燃料集合体を構成するハンドルと嵌合し得る溝又は凹部を、燃料浮き上がり防止部材を構成する格子部材の下面に設けた点が実施例１と異なる。その他の構成は実施例１と同様であり、実施例１と同様の構成要素に同一符号を付し、以下では実施例１と重複する説明を省略する。   FIG. 11: is the fragmentary top view of the fuel floating prevention member of Example 2 which concerns on the other Example of this invention, and its DD sectional arrow directional view. The present embodiment is different from the first embodiment in that a groove or a recess that can be fitted with a handle constituting the fuel assembly is provided on the lower surface of the lattice member constituting the fuel floating prevention member. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components as those of the first embodiment, and the description overlapping with the first embodiment is omitted below.

図１１の左図は、上述の実施例１において図７に示した構成と同様に、燃料浮き上がり防止部材３１を構成する格子部材３２の平面形状は、格子部材３２ａ、格子部材３２ｂ、及び格子部材３２ｃを三角格子状に組み合わせたものであり、それぞれの格子部材３２ａ、格子部材３２ｂ、及び格子部材３２ｃは、上述したように、燃料集合体１ａのハンドル７ａ、燃料集合体１ｂのハンドル７ｂ、及び燃料集合体１ｃのハンドル７ｃの上方に配される。また、図１にて説明したように、格子部材３２ａをハンドル７ａ上面の長辺７１ａに、格子部材３２ｂをハンドル７ｂ上面の長辺７１ｂに、また、格子部材３２ｃをハンドル７ｃの長辺７１ｃに交差するよう、燃料浮き上がり防止部材３１を構成する格子部材３２を配する。   In the left diagram of FIG. 11, the planar shape of the lattice member 32 constituting the fuel floating prevention member 31 is the lattice member 32a, the lattice member 32b, and the lattice member, similarly to the configuration shown in FIG. 32c are combined in a triangular lattice shape, and each of the lattice member 32a, the lattice member 32b, and the lattice member 32c includes the handle 7a of the fuel assembly 1a, the handle 7b of the fuel assembly 1b, and It is disposed above the handle 7c of the fuel assembly 1c. Further, as described in FIG. 1, the lattice member 32a is on the long side 71a on the top surface of the handle 7a, the lattice member 32b is on the long side 71b on the top surface of the handle 7b, and the lattice member 32c is on the long side 71c of the handle 7c. A grid member 32 constituting the fuel floating prevention member 31 is arranged so as to intersect.

図１１の右図は、左図のＤ―Ｄ断面矢視図である。右図に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２ａの下面に、燃料集合体１のハンドル７の上面と交差する位置に、溝３４（又は凹部）を設けている。
図１２は、図１１に示す燃料浮き上がり防止部材３１を構成する格子部材３２ａとハンドル７ａとの位置関係を示す部分平面図と、そのＥ―Ｅ断面矢視図であり、図１３は、図１１に示す燃料浮き上がり防止部材３１を構成する格子部材３２ａとハンドルとの位置関係を示す部分平面図と、そのＦ―Ｆ断面矢視図である。 The right figure of FIG. 11 is a DD cross-sectional arrow view of the left figure. As shown in the right figure, a groove 34 (or a recess) is provided on the lower surface of the lattice member 32 a constituting the fuel floating prevention member 31 at a position intersecting with the upper surface of the handle 7 of the fuel assembly 1.
FIG. 12 is a partial plan view showing the positional relationship between the grid member 32a and the handle 7a constituting the fuel floating prevention member 31 shown in FIG. 11, and its EE cross-sectional view, and FIG. FIG. 5 is a partial plan view showing a positional relationship between a lattice member 32a constituting the fuel floating prevention member 31 shown in FIG.

図１２の上図は、図１に示した燃料集合体１ａと燃料浮き上がり防止部材３１を構成する格子部材３２ａとの配置関係において、時計回り又は反時計回りに９０度回転させた状態での部分平面図であり、図１２の下図は、上図のＥ−Ｅ断面矢視図である。図１２の上図に示すように、格子部材３２ａは、ハンドル７ａ上面の長辺と略直交するよう交差している。また、図１２の下図に示すように、格子部材３２ａは、下面に略台形状の切り欠きを形成することにより得られる溝３４（又は凹部）を有する。また、溝３４（又は凹部）は、図１３の下図に示すように、格子部材３２ａの幅方向（短辺方向）に連続している。換言すれば、格子部材３２ａは、幅方向に連続する溝３４（又は凹部）を備える。溝３４（又は凹部）の底部、すなわち、図１２の下図において、格子部材３２ａの上面に最も近い部分は、平坦化され弾性体３３としてのコイルばねの一端が固定されている。このコイルばねの一端が固定された溝３４（又は凹部）の底部より、ハンドル７ａ側に向かうに従い、溝３４（又は凹部）の開口幅が緩やかに拡大するよう、ハンドル７ａ上面の短辺を挟みその両側に傾斜面を有する。このように、格子部材３２ａの下面に設けられた溝３４（又は凹部）が傾斜面を有することから、燃料集合体１ａを構成するハンドル７ａに対し格子部材３２ａの位置決めが容易となる。より詳細には、三角格子の繰り返しパターン形状を有する燃料浮き上がり防止部材３１を構成する格子部材３２を、炉心２１内に三角格子状に稠密に装荷される複数体の燃料集合体１の上方に配し、上述の図１０に示すように、炉心支持枠２３に固定する際において、格子部材３２の下面に設けられた溝３４（又は凹部）が傾斜面を有することから、燃料集合体１のハンドル７に対し上記傾斜面を介して、自己整合的に溝３４（又は凹部）をハンドル７の上面に嵌合させることが可能となり、燃料集合体１を構成するハンドル７に対し格子部材３２の位置決めが容易となる。   The upper diagram of FIG. 12 shows a portion of the fuel assembly 1a shown in FIG. 1 and the lattice member 32a constituting the fuel floating prevention member 31 in a state where the fuel assembly 1a is rotated 90 degrees clockwise or counterclockwise. It is a top view and the lower figure of FIG. 12 is an EE cross-sectional arrow view of the upper figure. As shown in the upper diagram of FIG. 12, the lattice member 32a intersects with the long side of the upper surface of the handle 7a so as to be substantially orthogonal. Moreover, as shown in the lower figure of FIG. 12, the lattice member 32a has a groove 34 (or a recess) obtained by forming a substantially trapezoidal notch on the lower surface. Moreover, the groove | channel 34 (or recessed part) is continuing in the width direction (short-side direction) of the lattice member 32a, as shown in the lower figure of FIG. In other words, the lattice member 32a includes grooves 34 (or recesses) that are continuous in the width direction. In the bottom of the groove 34 (or the recess), that is, in the lower part of FIG. 12, the part closest to the upper surface of the lattice member 32a is flattened, and one end of a coil spring as the elastic body 33 is fixed. The short side of the upper surface of the handle 7a is sandwiched so that the opening width of the groove 34 (or recess) gradually increases from the bottom of the groove 34 (or recess) to which the one end of the coil spring is fixed toward the handle 7a. It has an inclined surface on both sides. Thus, since the groove 34 (or recess) provided on the lower surface of the lattice member 32a has an inclined surface, the lattice member 32a can be easily positioned with respect to the handle 7a constituting the fuel assembly 1a. More specifically, a lattice member 32 constituting a fuel floating prevention member 31 having a triangular lattice repetitive pattern shape is arranged above a plurality of fuel assemblies 1 densely loaded in a triangular lattice shape in the core 21. As shown in FIG. 10 described above, the groove 34 (or recess) provided on the lower surface of the lattice member 32 has an inclined surface when being fixed to the core support frame 23, so that the handle of the fuel assembly 1 7, the groove 34 (or recess) can be fitted to the upper surface of the handle 7 in a self-aligning manner through the inclined surface, and the lattice member 32 is positioned with respect to the handle 7 constituting the fuel assembly 1. Becomes easy.

また、図１２の下図及び図１３の下図に示すように、格子部材３２ａの下面に設けられた溝３４（又は凹部）と、燃料集合体１ａを構成するハンドル７ａとが嵌合する。ここで、仮に、図１２の上図に白抜き矢印にて示すＡ方向への変位、すなわち、格子部材３２ａの長辺方向（長手方向）に沿った、振動或いは外力が燃料集合体１ａに付加された場合を想定する。図１２の下図に示すように、ハンドル７ａの長手方向に沿った２つの側面のうちいずれか一方が、格子部材３２ａの下面に設けられた溝３４（又は凹部）の傾斜面と当接することにより、燃料集合体１ａのＡ方向への変位が規制される。換言すれば、格子部材３２ａの下面に設けられた溝３４（又は凹部）は、燃料集合体１の変位を規制する変位規制部としての機能を有する。なお、この変位規制部としての機能は、図１１の左図において、白抜き矢印にて示す、Ｂ方向及びＣ方向の変位においても、それぞれ、燃料集合体１ｂ及び燃料集合体１ｃの変位を、格子部材３２ｂ及び格子部材３２ｃの下面に設けられた溝３４（又は凹部）により規制される。上述のように、格子部材３２の下面に設けられた溝３４（又は凹部）が燃料集合体１の変位規制部として機能することにより、実施例１において図６に示した制御棒接触防止パッド１２及び燃料集合体接触防止パッド１３を、燃料集合体１を構成するチャンネルボックス５の側面に設けることが不要となる。換言すれば、格子部材３２の下面に設けられた溝３４（又は凹部）が燃料集合体１の変位規制部として機能することにより、相互に隣接して配される燃料集合体１間の間隙及び水平断面（横断面）Ｙ字型の制御棒１１の挿入路としての間隙を確保することが可能となる。   Further, as shown in the lower diagram of FIG. 12 and the lower diagram of FIG. 13, the groove 34 (or the recess) provided in the lower surface of the lattice member 32a and the handle 7a constituting the fuel assembly 1a are fitted. Here, suppose that displacement in the A direction indicated by the white arrow in the upper diagram of FIG. 12, that is, vibration or external force along the long side direction (longitudinal direction) of the lattice member 32a is applied to the fuel assembly 1a. Assuming that As shown in the lower diagram of FIG. 12, either one of the two side surfaces along the longitudinal direction of the handle 7a abuts on the inclined surface of the groove 34 (or recess) provided on the lower surface of the lattice member 32a. The displacement of the fuel assembly 1a in the A direction is restricted. In other words, the grooves 34 (or recesses) provided on the lower surface of the lattice member 32 a have a function as a displacement restricting portion that restricts the displacement of the fuel assembly 1. In addition, the function as this displacement control part is the displacement of the fuel assembly 1b and the fuel assembly 1c, respectively, even in the displacement in the B direction and the C direction indicated by the white arrows in the left diagram of FIG. It is regulated by grooves 34 (or recesses) provided on the lower surfaces of the lattice member 32b and the lattice member 32c. As described above, the groove 34 (or recess) provided in the lower surface of the lattice member 32 functions as a displacement restricting portion of the fuel assembly 1, so that the control rod contact prevention pad 12 shown in FIG. In addition, it becomes unnecessary to provide the fuel assembly contact prevention pad 13 on the side surface of the channel box 5 constituting the fuel assembly 1. In other words, the grooves 34 (or recesses) provided in the lower surface of the lattice member 32 function as a displacement restricting portion of the fuel assembly 1, so that the gap between the fuel assemblies 1 arranged adjacent to each other and It is possible to secure a gap as an insertion path for the horizontal cross section (transverse section) Y-shaped control rod 11.

なお、格子部材３２の下面に設けられる溝３４（又は凹部）の開口幅は、嵌合するハンドル７の上面の幅（短辺）より大きければよく、開口幅は適宜設定すれば良い。   The opening width of the groove 34 (or recess) provided on the lower surface of the lattice member 32 may be larger than the width (short side) of the upper surface of the handle 7 to be fitted, and the opening width may be set as appropriate.

本実施例によれば、実施例１の効果に加え、燃料集合体を構成するハンドルに対し燃料浮き上がり防止部材を構成する格子部材の位置決めが容易となる。
また、本実施例によれば、燃料浮き上がり防止部材を構成する格子部材の下面に、燃料集合体を構成するハンドルと嵌合し得る溝（又は凹部）を有することから、燃料集合体の変位を規制することが可能となる。 According to the present embodiment, in addition to the effects of the first embodiment, the positioning of the lattice member constituting the fuel floating prevention member with respect to the handle constituting the fuel assembly is facilitated.
Further, according to the present embodiment, since the groove (or recess) that can be fitted to the handle constituting the fuel assembly is provided on the lower surface of the lattice member constituting the fuel floating prevention member, the displacement of the fuel assembly is reduced. It becomes possible to regulate.

図１４は、本発明の他の実施例に係る実施例３の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図であり、図１５は、図１４のＧ−Ｇ断面矢視図であって、燃料浮き上がり防止部材３と燃料集合体の上部との位置関係を示す図である。本実施例では、燃料浮き上がり防止部材を構成する格子部材のうち、燃料集合体のハンドルと交差するよう配される格子部材の下面に、燃料集合体がＹ字型の制御棒側へと向かう変位を規制するための燃料集合体変位規制部を設けた点が実施例１と異なる。その他の構成は実施例１と同様であり、実施例１と同様の構成要素に同一符号を付し、以下では実施例１と重複する説明を省略する。   FIG. 14 is a partial plan view of the core showing the positional relationship between the fuel floating prevention member and the fuel assembly of the third embodiment according to another embodiment of the present invention, and FIG. 15 is a cross-sectional view taken along the line GG in FIG. FIG. 4 is a view showing the positional relationship between the fuel floating prevention member 3 and the upper portion of the fuel assembly. In this embodiment, of the lattice members constituting the fuel floating prevention member, the fuel assembly is displaced toward the Y-shaped control rod side on the lower surface of the lattice member arranged to intersect the handle of the fuel assembly. The difference from the first embodiment is that a fuel assembly displacement restricting portion for restricting the fuel is provided. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components as those of the first embodiment, and the description overlapping with the first embodiment is omitted below.

図１４に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２のうち、格子部材３２ａは燃料集合体１ａを構成するハンドル７ａ上面の長辺と交差するよう配されると共に、格子部材３２ｂは燃料集合体１ｂを構成するハンドル７ｂ上面の長辺と交差するよう配される。
図１５に示すように、弾性体３３としてのコイルばねの軸方向上端面が、格子部材３２ａの下面に固定され燃料浮き上がり防止部材３１が構成される。この場合、燃料浮き上がり防止部材３１を構成する弾性体３３としてのコイルばねの軸方向下端面（弾性体３３の格子部材３２ａの下面とは反対側の面）は、燃料集合体１ａを構成するハンドル７ａに固定されることなく、当接している。また、弾性体３３としてのコイルばねの軸方向上端面が、格子部材３２ｃの下面に固定され燃料浮き上がり防止部材３１が構成される。この場合、燃料浮き上がり防止部材３１を構成する弾性体３３としてのコイルばねの軸方向下端面（弾性体３３の格子部材３２ｃの下面とは反対側の面）は、燃料集合体１ｃを構成するハンドル７ｃａに固定されることなく、当接している。
格子部材３２ａの下面うち、弾性体３３としてのコイルばねが固定される位置の近傍からＹ字型の制御棒１１へと向かう領域に、燃料集合体１ａ側へ突出する凸部を有する。また、格子部材３２ｃの下面うち、弾性体３３としてのコイルばねが固定される位置の近傍からＹ字型の制御棒１１へと向かう領域に、燃料集合体１ｃ側へ突出する凸部を有する。これら、格子部材３２ａの下面に設けられた凸部と格子部材３２ｃの下面に設けられた凸部は、格子部材３２ａ及び格子部材３２ｃの接続部を介して連続し、燃料集合体変位規制部３５を構成する。格子部材３２ａ及び格子部材３２ｃの接続部は、Ｙ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）（図示せず）の直上に位置する。また、図１５に示すように、格子部材３２ａ及び格子部材３２ｃの下面に設けられる燃料集合体変位規制部３５のうち、格子部材３２ａの側の端面は、格子部材３２ａの下面より燃料集合体１ａ側へと向かうに従いＹ字型の制御棒１１の中心側へと比較的急峻に傾斜する傾斜面を有する。また、燃料集合体変位規制部３５のうち、格子部材３２ｃの側の端面は、格子部材３２ｃの下面より燃料集合体１ｃ側へと向かうに従いＹ字型の制御棒１１の中心側へと比較的急峻に傾斜する傾斜面を有する。 As shown in FIG. 14, among the lattice members 32 constituting the fuel floating prevention member 31, the lattice member 32a is arranged so as to intersect the long side of the upper surface of the handle 7a constituting the fuel assembly 1a, and the lattice member 32b. Is arranged so as to intersect with the long side of the upper surface of the handle 7b constituting the fuel assembly 1b.
As shown in FIG. 15, the upper end surface in the axial direction of the coil spring as the elastic body 33 is fixed to the lower surface of the lattice member 32 a to constitute the fuel floating prevention member 31. In this case, the axial lower end surface (surface opposite to the lower surface of the lattice member 32a of the elastic body 33) of the coil spring as the elastic body 33 constituting the fuel floating prevention member 31 is a handle constituting the fuel assembly 1a. It abuts without being fixed to 7a. Further, the upper end surface in the axial direction of the coil spring as the elastic body 33 is fixed to the lower surface of the lattice member 32c, and the fuel floating prevention member 31 is configured. In this case, the axial lower end surface (surface opposite to the lower surface of the lattice member 32c of the elastic body 33) of the coil spring as the elastic body 33 constituting the fuel floating prevention member 31 is the handle constituting the fuel assembly 1c. It is contacting without being fixed to 7ca.
Of the lower surface of the lattice member 32a, a protrusion projecting toward the fuel assembly 1a is provided in a region from the vicinity of the position where the coil spring as the elastic body 33 is fixed to the Y-shaped control rod 11. Further, in the lower surface of the lattice member 32c, a protrusion projecting toward the fuel assembly 1c is provided in a region from the vicinity of the position where the coil spring as the elastic body 33 is fixed to the Y-shaped control rod 11. The convex portion provided on the lower surface of the lattice member 32a and the convex portion provided on the lower surface of the lattice member 32c are continuous via the connecting portion of the lattice member 32a and the lattice member 32c, and the fuel assembly displacement regulating portion 35 is provided. Configure. The connecting portion between the lattice member 32a and the lattice member 32c is located immediately above a tie rod (or center post) (not shown) that is the center of the Y-shaped control rod 11. Further, as shown in FIG. 15, among the fuel assembly displacement regulating portions 35 provided on the lower surfaces of the lattice member 32a and the lattice member 32c, the end surface on the lattice member 32a side is closer to the fuel assembly 1a than the lower surface of the lattice member 32a. As it goes to the side, it has an inclined surface that inclines relatively steeply toward the center of the Y-shaped control rod 11. Further, in the fuel assembly displacement restricting portion 35, the end surface on the lattice member 32c side is relatively closer to the center side of the Y-shaped control rod 11 as it goes from the lower surface of the lattice member 32c toward the fuel assembly 1c. It has an inclined surface that is steeply inclined.

ここで、図１４及び図１５に白抜き矢印にて示すＡ方向及びＢ方向への変位、すなわち、格子部材３２ａの長辺方向（長手方向）に沿って、Ｙ字型の制御棒１１の中心側へと向かう水平方向の振動或いは外力が燃料集合体１ａに付加され、格子部材３２ｃの長辺方向（長手方向）に沿って、Ｙ字型の制御棒１１の中心側へと向かう水平方向の振動或いは外力が燃料集合体１ｃに付加された場合を想定する。この場合、図１５に示すように、燃料集合体１ａを構成するハンドル７ａの長手方向に沿った２つの側面のうちＹ字型の制御棒１１の中心側の側面が、燃料集合体変位規制部３５の一方の端面である傾斜面と当接し、燃料集合体１ａのＡ方向への変位が規制される。また、燃料集合体１ｃを構成するハンドル７ｃの長手方向に沿った２つの側面のうちＹ字型の制御棒１１の中心側の側面が、燃料集合体変位規制部３５の他方の端面である傾斜面と当接し、燃料集合体１ｃのＣ方向への変位が規制される。これにより、燃料集合体１ａ及び燃料集合体１ｃ間に形成される間隙、すなわち、水平断面（横断面）Ｙ字型の制御棒１１の挿入路としての間隙を確保することが可能となる。よって、本実施例では、実施例１において図６に示した制御棒接触防止パッド１２を、燃料集合体１を構成するチャンネルボックス５の側面に設けることが不要となる。   Here, the center of the Y-shaped control rod 11 along the displacement in the A direction and the B direction indicated by the white arrows in FIGS. 14 and 15, that is, along the long side direction (longitudinal direction) of the lattice member 32a. A horizontal vibration or external force toward the side is applied to the fuel assembly 1a, and a horizontal direction toward the center of the Y-shaped control rod 11 along the long side direction (longitudinal direction) of the lattice member 32c. It is assumed that vibration or external force is applied to the fuel assembly 1c. In this case, as shown in FIG. 15, the side surface on the center side of the Y-shaped control rod 11 among the two side surfaces along the longitudinal direction of the handle 7a constituting the fuel assembly 1a is the fuel assembly displacement restricting portion. Abutting with the inclined surface which is one end surface of 35, displacement of the fuel assembly 1a in the A direction is restricted. Further, of the two side surfaces along the longitudinal direction of the handle 7c constituting the fuel assembly 1c, the side surface on the center side of the Y-shaped control rod 11 is an inclination that is the other end surface of the fuel assembly displacement restricting portion 35. Contact with the surface restricts displacement of the fuel assembly 1c in the C direction. As a result, it is possible to secure a gap formed between the fuel assembly 1a and the fuel assembly 1c, that is, a gap as an insertion path for the Y-shaped control rod 11 having a horizontal section (transverse section). Therefore, in this embodiment, it is not necessary to provide the control rod contact prevention pad 12 shown in FIG. 6 in Embodiment 1 on the side surface of the channel box 5 constituting the fuel assembly 1.

本実施例によれば、実施例１の効果に加え、燃料浮き上がり防止部材を構成する格子部材の下面に、燃料集合体変位規制部を有することから、燃料集合体のＹ字型の制御棒側への変位を規制することが可能となる。   According to the present embodiment, in addition to the effects of the first embodiment, since the fuel assembly displacement restricting portion is provided on the lower surface of the lattice member constituting the fuel floating prevention member, the fuel assembly has a Y-shaped control rod side. It becomes possible to regulate the displacement to the.

図１６は、本発明の他の実施例に係る実施例４の燃料浮き上がり防止部材の部分平面図と、そのＨ―Ｈ断面矢視図及びＩ―Ｉ断面矢視図である。本実施例では、燃料浮き上がり防止部材を構成する格子部材のうち、ハンドルと交差する領域以外の領域における格子部材の下面の形状を、下方（燃料集合体側）に向かうに従い幅が小さくなる、すなわち、垂直断面形状が細くなるよう構成した点が実施例１と異なる。その他の構成は実施例１と同様であり、実施例１と同様の構成要素に同一符号を付し、以下では実施例１と重複する説明を省略する。   FIG. 16: is the fragmentary top view of the fuel floating prevention member of Example 4 which concerns on the other Example of this invention, its HH cross section arrow view, and II cross section arrow view. In this embodiment, among the lattice members constituting the fuel floating prevention member, the width of the lower surface of the lattice member in the region other than the region intersecting with the handle is reduced toward the lower side (fuel assembly side). The difference from the first embodiment is that the vertical cross-sectional shape is reduced. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components as those of the first embodiment, and the description overlapping with the first embodiment is omitted below.

図１６の上図に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２のうち、格子部材３２ａは燃料集合体１ａを構成するハンドル７ａ上面の長辺と交差するよう配されると共に、格子部材３２ｂは燃料集合体１ｂを構成するハンドル７ｂ上面の長辺と交差するよう配され、格子部材３２ｃは燃料集合体１ｃを構成するハンドル７ｃ上面の長辺と交差するよう配される。   As shown in the upper diagram of FIG. 16, among the lattice members 32 constituting the fuel floating prevention member 31, the lattice member 32a is arranged so as to intersect the long side of the upper surface of the handle 7a constituting the fuel assembly 1a, The lattice member 32b is arranged so as to intersect with the long side of the upper surface of the handle 7b constituting the fuel assembly 1b, and the lattice member 32c is arranged so as to intersect with the long side of the upper surface of the handle 7c constituting the fuel assembly 1c.

図１６の左下図に示すように、上図における格子部材３２ａのＨ―Ｈ断面形状は、四角形状を成す。このＨ―Ｈ断面の位置が、燃料集合体１ａを構成するハンドル７ａ上面の長辺と交差する位置に相当する。一方、図１６の右下図に示すように、上図における格子部材３２ａのＩ―Ｉ断面形状は、下部側の形状が下方（燃料集合体側）へ向かうに従い幅が小さくなる、すなわち、垂直断面形状が細くなる形状を有する。このＩ―Ｉ断面の位置は、燃料集合体１ａを構成するハンドル７ａ上面の長辺と交差しない位置に相当する。すなわち、本実施例の燃料浮き上がり防止部材３１を構成する格子部材３２は、燃料集合体１を構成するハンドル７と交差する領域においては、その垂直断面形状を四角形状とすることで、図示しない弾性体３３としてのコイルばねの一端を固定し易い形状とすると共に、ハンドル７と交差しない領域においては垂直断面形状が、下部側において下方（燃料集合体側）へ向かうに従い幅が小さくなる、すなわち、垂直断面形状が細くなる形状とすることで、燃料集合体１内を上方へと通流する冷却水（冷却材）に対する圧損が低減される。換言すれば、燃料浮き上がり防止部材３１を構成する格子部材３２のうち、燃料集合体１を構成するハンドル７と交差する領域以外の領域において、燃料集合体１の上部出口から流出する流体（冷却水）が格子部材３２に衝突する際、格子部材３２で受ける流体力を低減できる。これにより、燃料浮き上がり防止部材３１の健全性を向上することが可能となる。   As shown in the lower left diagram of FIG. 16, the HH cross-sectional shape of the lattice member 32a in the upper diagram is a quadrilateral shape. The position of the HH cross section corresponds to the position intersecting the long side of the upper surface of the handle 7a constituting the fuel assembly 1a. On the other hand, as shown in the lower right figure of FIG. 16, the II cross-sectional shape of the lattice member 32a in the upper figure becomes smaller as the lower side shape goes downward (fuel assembly side), that is, the vertical cross-sectional shape. Has a shape that narrows. The position of the II section corresponds to a position that does not intersect the long side of the upper surface of the handle 7a constituting the fuel assembly 1a. That is, the lattice member 32 constituting the fuel floating prevention member 31 of the present embodiment has a rectangular cross section in a region intersecting with the handle 7 constituting the fuel assembly 1, thereby forming an elastic (not shown). One end of the coil spring as the body 33 is easily fixed, and the vertical cross-sectional shape in the region not intersecting with the handle 7 is reduced in width toward the lower side (fuel assembly side) on the lower side, that is, vertical. By making the cross-sectional shape thinner, the pressure loss to the cooling water (coolant) flowing upward in the fuel assembly 1 is reduced. In other words, the fluid (cooling water) flowing out from the upper outlet of the fuel assembly 1 in the region other than the region intersecting the handle 7 constituting the fuel assembly 1 in the lattice member 32 constituting the fuel floating prevention member 31. ) Impinges on the lattice member 32, the fluid force received by the lattice member 32 can be reduced. Thereby, it is possible to improve the soundness of the fuel floating prevention member 31.

本実施例によれば、実施例１の効果に加え、冷却水である流体の衝突による燃料浮き上がり防止部材が受ける流体力を低減でき、燃料浮き上がり防止部材の健全性の向上を図ることが可能となる。   According to the present embodiment, in addition to the effects of the first embodiment, it is possible to reduce the fluid force received by the fuel floating prevention member due to the collision of the fluid that is the cooling water, and to improve the soundness of the fuel floating prevention member. Become.

図１７は、本発明の他の実施例に係る実施例５の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。本実施例では、燃料浮き上がり防止部材を構成する各格子部材に、各燃料集合体を構成するハンドルの上面と対応して延伸する格子拡大部材を有する構成とした点が実施例１と異なる。その他の構成は実施例１と同様であり、実施例１と同様の構成要素に同一符号を付し、以下では実施例１と重複する説明を省略する。   FIG. 17 is a partial plan view of the core showing the positional relationship between the fuel floating prevention member and the fuel assembly according to the fifth embodiment of the present invention. The present embodiment is different from the first embodiment in that each lattice member constituting the fuel floating prevention member has a lattice enlargement member extending corresponding to the upper surface of the handle constituting each fuel assembly. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components as those of the first embodiment, and the description overlapping with the first embodiment is omitted below.

図１７に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２のうち、燃料集合体１ａを構成するハンドル７ａ上面の長辺と交差するよう配される格子部材３２ａは、当該ハンドル７ａ上面の長辺と交差する位置に、ハンドル７ａの上面に対応して延伸する格子拡大部材３６ａを有する。図１７に示すように、格子拡大部材３６ａの平面の面積は、ハンドル７ａの上面の面積以上である。格子部材３２ａと格子拡大部材３６ａは相互に直交する。また、燃料集合体１ｂを構成するハンドル７ｂ上面の長辺と交差するよう配される格子部材３２ｂは、当該ハンドル７ｂ上面の長辺と交差する位置に、ハンドル７ｂの上面に対応して延伸する格子拡大部材３６ｂを有する。格子拡大部材３６ｂの平面の面積はハンドル７ｂの上面の面積以上であり、格子部材３２ｂと格子拡大部材３６ｂは相互に直交する。同様に、燃料集合体１ｃを構成するハンドル７ｃ上面の長辺と交差するよう配される格子部材３２ｃは、当該ハンドル７ｃ上面の長辺と交差する位置に、ハンドル７ｃの上面に対応して延伸する格子拡大部材３６ｃを有する。格子拡大部材３６ｃの平面の面積はハンドル７ｃの上面の面積以上であり、格子部材３２ｃと格子拡大部材３６ｃは相互に直交する。   As shown in FIG. 17, among the lattice members 32 constituting the fuel floating prevention member 31, the lattice member 32a arranged to intersect the long side of the upper surface of the handle 7a constituting the fuel assembly 1a is the upper surface of the handle 7a. A grid expanding member 36a extending corresponding to the upper surface of the handle 7a is provided at a position intersecting with the long side. As shown in FIG. 17, the area of the plane of the lattice expansion member 36a is equal to or larger than the area of the upper surface of the handle 7a. The lattice member 32a and the lattice enlargement member 36a are orthogonal to each other. Further, the lattice member 32b arranged so as to intersect with the long side of the upper surface of the handle 7b constituting the fuel assembly 1b extends to a position intersecting with the long side of the upper surface of the handle 7b corresponding to the upper surface of the handle 7b. It has a lattice expansion member 36b. The area of the plane of the lattice expansion member 36b is equal to or larger than the area of the upper surface of the handle 7b, and the lattice member 32b and the lattice expansion member 36b are orthogonal to each other. Similarly, the lattice member 32c arranged so as to intersect with the long side of the upper surface of the handle 7c constituting the fuel assembly 1c extends to the position intersecting with the long side of the upper surface of the handle 7c corresponding to the upper surface of the handle 7c. It has a lattice expansion member 36c. The area of the plane of the lattice expansion member 36c is equal to or larger than the area of the upper surface of the handle 7c, and the lattice member 32c and the lattice expansion member 36c are orthogonal to each other.

図１８は、図１７に示す燃料浮き上がり防止部材３１を構成する格子部材３２ａ及び格子拡大部材３６ａ並びにハンドル７ａとの位置関係を示す部分平面図とそのＪ―Ｊ断面矢視図であり、図１９は、図１７に示す燃料浮き上がり防止部材３１を構成する格子部材３２ａ及び格子拡大部材３６ａ並びにハンドル７ａとの位置関係を示す部分平面図と、そのＫ―Ｋ断面矢視図である。
図１８の上図は、図１７に示した燃料集合体１ａと燃料浮き上がり防止部材３１を構成する格子部材３２ａとの配置関係において、時計回り又は反時計回りに９０度回転させた状態での部分平面図であり、図１８の下図は、上図のＪ―Ｊ断面矢視図である。図１８の上図に示すように、格子拡大部材３６ａは、燃料集合体１ａを構成するハンドル７ａの上面と同等の長さ及び同等の幅を有する。弾性体３３としてのコイルばねの一端は、格子拡大部材３６ａの下面に固定され、弾性体３３としてのコイルばねの一端はハンドル７ａに固定されることなく、当接している。 18 is a partial plan view showing the positional relationship between the lattice member 32a, the lattice expansion member 36a and the handle 7a constituting the fuel floating prevention member 31 shown in FIG. These are the partial top view which shows the positional relationship with the lattice member 32a and the lattice expansion member 36a which comprise the fuel floating prevention member 31 shown in FIG. 17, and the handle | steering-wheel 7a, and its KK cross-sectional arrow view.
The upper part of FIG. 18 shows a portion of the fuel assembly 1a shown in FIG. 17 and the lattice member 32a constituting the fuel floating prevention member 31 in a state where the fuel assembly 1a is rotated 90 degrees clockwise or counterclockwise. FIG. 18 is a plan view, and a lower diagram in FIG. 18 is a cross-sectional view taken along the line JJ in the upper diagram. As shown in the upper diagram of FIG. 18, the lattice expansion member 36a has the same length and the same width as the upper surface of the handle 7a constituting the fuel assembly 1a. One end of the coil spring as the elastic body 33 is fixed to the lower surface of the lattice expanding member 36a, and one end of the coil spring as the elastic body 33 is in contact with the handle 7a without being fixed.

図１９の上図は、図１７に示した燃料集合体１ａと、格子部材３２ａ及び格子拡大部材３６ａとの配置関係と同様であり、図１９の下図は、Ｋ―Ｋ断面矢視図である。図１９の下図に示すように、格子拡大部材３６ａの下面に、長手方向に沿って相互に離間し、一端が固定される２つの弾性体３３としてのコイルばねを備える。２つの弾性体３３としてのコイルばねの他端は固定されることなく、ハンドル７ａの上面と当接している。このように、格子拡大部材３６ａにて、ハンドル７ａの上面全面にて、燃料集合体１ａの軸方向上への浮き上がりを防止できる。なお、図１９の下図に示すように、格子拡大部材３６ａを有することにより、弾性体３３としてのコイルばねを複数配することが可能となり、１つ当たりのコイルばね（弾性体３３）への負荷を低減することも可能となる。   The upper diagram of FIG. 19 is the same as the arrangement relationship of the fuel assembly 1a shown in FIG. 17, the lattice member 32a, and the lattice expansion member 36a, and the lower diagram of FIG. . As shown in the lower part of FIG. 19, the lower surface of the lattice expansion member 36a is provided with coil springs as two elastic bodies 33 which are spaced apart from each other along the longitudinal direction and fixed at one end. The other ends of the coil springs as the two elastic bodies 33 are not fixed and are in contact with the upper surface of the handle 7a. As described above, the lattice expanding member 36a can prevent the fuel assembly 1a from being lifted up in the axial direction over the entire upper surface of the handle 7a. In addition, as shown in the lower figure of FIG. 19, by having the lattice expansion member 36a, it becomes possible to arrange a plurality of coil springs as the elastic body 33, and the load to one coil spring (elastic body 33). Can also be reduced.

本実施例によれば、実施例１による効果に加え、料浮き上がり防止部材を構成する各格子部材に格子拡大部材を備えることで、より効果的に燃料集合体の浮き上がりを防止することができる。
また、本実施例によれば、燃料浮き上がり防止部材及び／又は燃料集合体が損傷することを防止すために配される弾性体の負荷を低減でき、弾性体の長寿命化を図ることが可能となる。 According to the present embodiment, in addition to the effects of the first embodiment, each lattice member constituting the material floating prevention member is provided with the lattice expansion member, so that the lift of the fuel assembly can be more effectively prevented.
Further, according to the present embodiment, it is possible to reduce the load of the elastic body arranged to prevent the fuel floating prevention member and / or the fuel assembly from being damaged, and to extend the life of the elastic body. It becomes.

図２０は、本発明の他の実施例に係る実施例６の燃料浮き上がり防止部材及び燃料集合体との配置関係を示す炉心の部分平面図である。本実施例では、燃料集合体を構成するハンドル上面の短辺（ハンドルの長手方向の両端部を画定する辺）がＹ字型の制御棒の中心であるタイロッド（またはセンタポスト）を向くよう燃料集合体を炉心に装荷する共に、複数の格子部材の接続部がハンドル上面の長辺と交差するよう燃料浮き上がり防止部材を構成する格子部材を配する点が実施例１と異なる。その他の構成は実施例１と同様であり、実施例１と同様の構成要素に同一符号を付し、以下では実施例１と重複する説明を省略する。   FIG. 20 is a partial plan view of the core showing the positional relationship between the fuel floating prevention member and the fuel assembly according to the sixth embodiment of the present invention. In this embodiment, the fuel is such that the short side of the upper surface of the handle constituting the fuel assembly (the side defining both ends in the longitudinal direction of the handle) faces the tie rod (or center post) that is the center of the Y-shaped control rod. The difference from the first embodiment is that the assembly is loaded on the core and the lattice member constituting the fuel floating prevention member is arranged so that the connecting portions of the plurality of lattice members intersect the long side of the upper surface of the handle. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components as those of the first embodiment, and the description overlapping with the first embodiment is omitted below.

図２０に示すように、相互に隣接し三角格子状に稠密に配される燃料集合体１ａ、燃料集合体１ｂ、及び燃料集合体１ｃの間に水平断面（横断面）がＹ字型の制御棒１１が配されている。燃料集合体１ａを構成するハンドル７ａ上面の短辺７２ａ（ハンドル７ａの長手方向に沿った両側面を画定する辺）、燃料集合体１ｂを構成するハンドル７ｂ上面の短辺７２ｂ（ハンドル７ｂの長手方向に沿った両側面を画定する辺）、及び燃料集合体１ｃを構成するハンドル７ｃ上面の短辺７２ｃ（ハンドル７ｃの長手方向に沿った両側面を画定する辺）は、Ｙ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）（図示せず）に向かうよう配されている。このような配置関係は、相互に隣接して三角格子状に配される他の３体の燃料集合体と、これら３体の燃料集合体１間にＹ字型の制御棒１１が配される場合においても同様である。このように、水平断面（横断面）がＹ字型の制御棒１１を囲むよう、相互に隣接して三角格子状に稠密に配される３体の燃料集合体１ａ〜１ｃのハンドル７ａ〜７ｃ上面の短辺７２ａ〜７２ｃの全てが、水平断面（横断面）がＹ字型の制御棒１１の中心であるタイロッド（またはセンタポスト）に向くよう配されることから、原子炉運転時におけるハンドル７ａ〜７ｃの配置を変更することなく、定期検査或いは燃料交換等を実施でき、作業性を向上することが可能となる。   As shown in FIG. 20, the horizontal cross section (cross section) is Y-shaped control between the fuel assemblies 1a, the fuel assemblies 1b, and the fuel assemblies 1c that are adjacent to each other and densely arranged in a triangular lattice shape. A bar 11 is arranged. The short side 72a of the upper surface of the handle 7a constituting the fuel assembly 1a (side defining both side surfaces along the longitudinal direction of the handle 7a), and the short side 72b of the upper surface of the handle 7b constituting the fuel assembly 1b (the length of the handle 7b) Side defining the both side surfaces along the direction) and the short side 72c of the upper surface of the handle 7c constituting the fuel assembly 1c (side defining both side surfaces along the longitudinal direction of the handle 7c) are Y-shaped control. It is arranged to face the tie rod (or center post) (not shown) which is the center of the rod 11. Such an arrangement relationship is such that three other fuel assemblies arranged in a triangular lattice pattern adjacent to each other, and a Y-shaped control rod 11 are arranged between these three fuel assemblies 1. The same applies to cases. As described above, the handles 7a to 7c of the three fuel assemblies 1a to 1c that are densely arranged adjacent to each other in a triangular lattice so that the horizontal cross section (transverse cross section) surrounds the Y-shaped control rod 11 are arranged. Since all of the short sides 72a to 72c on the upper surface are arranged so that the horizontal cross section (transverse cross section) faces the tie rod (or center post) that is the center of the Y-shaped control rod 11, the handle during operation of the reactor Periodic inspection or fuel replacement can be performed without changing the arrangement of 7a to 7c, and workability can be improved.

また、図２０に示すように、燃料浮き上がり防止部材３１を構成する格子部材３２は、三角格子の繰り返しパターン形状を備える。例えば、燃料集合体１ａのハンドル７ａの上方に配される格子部材３２は、ハンドル７ａ上面の長辺７１ａ（ハンドル７ａの長手方向に沿った両側面を画定する辺）と略直交するよう長辺７１ａの略中央部に配される格子部材３２ａ、長辺７１ａの略中央部にて長辺７１ａに対し所定の傾斜角にて交差する格子部材３２ｄ、及び長辺７１ａの略中央部にて長辺７１ａに対し所定の傾斜角にて交差する格子部材３２ｅを有する。換言すれば、格子部材３２ａ、格子部材３２ｄ、及び格子部材３２ｅの接続部が長辺７１ａの略中央部上方に位置する。格子部材３２ａ、格子部材３２ｄ、及び格子部材３２ｅの接続部の下面に一端が固定され、他端がハンドル７ａの上面に固定されることなく当接する弾性体３３としてのコイルばね（図示せず）が設けられている。   Moreover, as shown in FIG. 20, the lattice member 32 which comprises the fuel floating prevention member 31 is provided with the repeating pattern shape of a triangular lattice. For example, the lattice member 32 disposed above the handle 7a of the fuel assembly 1a has long sides so as to be substantially orthogonal to the long sides 71a (sides defining both side surfaces along the longitudinal direction of the handle 7a) of the upper surface of the handle 7a. Lattice member 32a arranged at a substantially central portion of 71a, a lattice member 32d intersecting the long side 71a at a predetermined inclination angle at a substantially central portion of the long side 71a, and a long portion at a substantially central portion of the long side 71a. The grid member 32e intersects the side 71a at a predetermined inclination angle. In other words, the connecting portion of the lattice member 32a, the lattice member 32d, and the lattice member 32e is positioned substantially above the center of the long side 71a. A coil spring (not shown) as an elastic body 33 with one end fixed to the lower surface of the connecting portion of the lattice member 32a, lattice member 32d, and lattice member 32e and the other end abutting without being fixed to the upper surface of the handle 7a. Is provided.

上述の関係は、他の相互に隣接して三角格子状に配される３体の燃料集合体１と、これら３体の燃料集合体１の上方に配される格子部材３２についても同様である。このように、各燃料集合体１は、３本の格子部材の接続部にて浮き上がりが防止されることから、格子部材３２により構成される燃料浮き上がり防止部材３１の健全性が向上される。   The above-described relationship is the same for the three fuel assemblies 1 arranged in a triangular lattice shape adjacent to each other and the lattice members 32 arranged above the three fuel assemblies 1. . As described above, each fuel assembly 1 is prevented from being lifted at the connection portion of the three lattice members, and thus the soundness of the fuel lift preventing member 31 constituted by the lattice member 32 is improved.

なお、３本の格子部材の接続部の下面の形状は、上述の実施例１（図８、図９）又は実施例２（図１２、図１３）と同様の形状とすれば良く、また、実施例５に示した格子拡大部材（図１７〜図１９）を備える構成としても良い。更には、格子部材において接続部以外の領域の下面の形状を上述の実施例４に示した形状（図１６の右下図）としても良い。   In addition, the shape of the lower surface of the connection part of the three lattice members may be the same as that of the above-described Example 1 (FIGS. 8 and 9) or Example 2 (FIGS. 12 and 13). It is good also as a structure provided with the lattice expansion member (FIGS. 17-19) shown in Example 5. FIG. Furthermore, the shape of the lower surface of the region other than the connection portion in the lattice member may be the shape shown in the above-described embodiment 4 (the lower right diagram in FIG. 16).

本実施例によれば、実施例１の効果に加え、燃料浮き上がり防止部材を構成する複数本の格子部材の接続部にて、燃料集合体の浮き上がりが防止されることから、燃料浮き上がり防止部材の健全性を更に向上することが可能となる。   According to the present embodiment, in addition to the effects of the first embodiment, the fuel assembly is prevented from rising at the connecting portions of the plurality of lattice members constituting the fuel floating prevention member. Soundness can be further improved.

なお、上述の実施例１〜実施例６では、沸騰水型原子炉の一例として、資源再利用型沸騰水型原子炉（ＲＢＷＲ）を示したが、これに限られるものではなく、水平断面が六角形状のチャンネルボックスを有する燃料集合体を、相互に隣接して三角格子状に稠密に装荷する炉心構造であれば、例えば、改良型沸騰水型原子炉（ＡＢＷＲ）、高経済性単純化沸騰水型原子炉（ＥＳＢＷＲ）、或いは再循環ポンプを有する通常の沸騰水型原子炉（ＢＷＲ）にも同様に適用できる。   In Examples 1 to 6, the resource reuse type boiling water reactor (RBWR) is shown as an example of the boiling water reactor. However, the present invention is not limited to this, and a horizontal cross section is shown. For example, an improved boiling water reactor (ABWR), a high-efficiency simplified boiling, if a core structure in which fuel assemblies having hexagonal channel boxes are densely loaded adjacent to each other in a triangular lattice shape The present invention can be similarly applied to a water reactor (ESBWR) or a normal boiling water reactor (BWR) having a recirculation pump.

また、上述の実施例２〜実施例５に示した構成を、任意の組み合わせにて沸騰水型原子炉を構成しても良い。例えば、実施例２と実施例３とを組み合わせ、格子部材３２の下面に溝３４（又は凹部）及び燃料集合体変位規制部３５を備える構成としても良い。また、実施例２と実施例４とを組み合わせ、格子部材３２の下面であってハンドルと交差する領域に溝３４（又は凹部）を設け、ハンドルと交差する領域以外の領域における格子部材３２の下面の形状を垂直断面形状が細くする構成としても良い。また、実施例２〜実施例５の構成を全て組み合わせても良く、すなわち、実施例２〜実施例５のうち、２つ以上の実施例を任意に組み合わせても良い。   Moreover, you may comprise a boiling water reactor by the structure shown in the above-mentioned Example 2-Example 5 by arbitrary combinations. For example, the second embodiment and the third embodiment may be combined, and the configuration may be such that the groove 34 (or the recess) and the fuel assembly displacement regulating portion 35 are provided on the lower surface of the lattice member 32. Also, the second embodiment and the fourth embodiment are combined, and a groove 34 (or a recess) is provided in the lower surface of the lattice member 32 and intersects the handle, and the lower surface of the lattice member 32 in a region other than the region intersecting the handle. The configuration may be such that the vertical cross-sectional shape is narrow. Moreover, you may combine all the structures of Example 2-Example 5, ie, among Example 2-Example 5, you may combine 2 or more Examples arbitrarily.

なお、本発明は上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。   In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

１，１ａ，１ｂ，１ｃ・・・燃料集合体
２・・・燃料棒
３・・・上部タイプレート
４・・・下部タイプレート
５・・・チャンネルボックス
６・・・燃料スペーサ
７，７ａ，７ｂ，７ｃ・・・ハンドル
８・・・燃料支持金具
９・・・上部開口部
１０・・・制御棒移動用開口部
１１・・・制御棒
１２・・・制御棒接触防止パッド
１３・・・燃料集合体接触防止パッド
１４・・・インターナルポンプ
２０・・・原子炉圧力容器
２１・・・炉心
２２・・・炉心支持板
２３・・・炉心支持枠
２４・・・炉心シュラウド
２５・・・シュラウドヘッド
２６・・・ダウンカマ
２７・・・気水分離器
２８・・・蒸気乾燥器
２９ａ・・・主蒸気配管
２９ｂ・・・給水配管
３０・・・下部プレナム
３１・・・燃料浮き上がり防止部材
３２，３２ａ，３２ｂ，３２ｃ，３２ｄ，３２ｅ・・・格子部材
３３・・・弾性体
３４・・・溝
３５・・・燃料集合体変位規制部
３６ａ，３６ｂ，３６ｃ，３６ｄ，３６ｅ・・・格子拡大部材
７１ａ，７１ｂ，７１ｃ・・・長辺７１ａ，７１ｂ，７１ｃ
７２ａ，７２ｂ，７２ｃ・・・短辺７２ａ，７２ｂ，７２ｃ 1, 1a, 1b, 1c ... Fuel assembly 2 ... Fuel rod 3 ... Upper tie plate 4 ... Lower tie plate 5 ... Channel box 6 ... Fuel spacers 7, 7a, 7b 7c ... handle 8 ... fuel support fitting 9 ... upper opening 10 ... control rod moving opening 11 ... control rod 12 ... control rod contact prevention pad 13 ... fuel Aggregate contact prevention pad 14 ... internal pump 20 ... reactor pressure vessel 21 ... core 22 ... core support plate 23 ... core support frame 24 ... core shroud 25 ... shroud Head 26 ... Downcomer 27 ... Steam separator 28 ... Steam dryer 29a ... Main steam pipe 29b ... Water supply pipe 30 ... Lower plenum 31 ... Fuel lift prevention member 32, 32a, 32b, 32c, 2d, 32e ... lattice member 33 ... elastic body 34 ... groove 35 ... fuel assembly displacement restricting portions 36a, 36b, 36c, 36d, 36e ... lattice expanding members 71a, 71b, 71c ..Long sides 71a, 71b, 71c
72a, 72b, 72c ... short sides 72a, 72b, 72c

Claims (15)

燃料集合体が三角格子状配列で稠密に配置され、３体の燃料集合体の中心に水平断面Ｙ字型の制御棒が挿入される沸騰水型原子炉の炉心であって、
前記燃料集合体は、前記水平断面Ｙ字型の制御棒を囲む３体の燃料集合体に設けられるハンドルの上面の長辺又は短辺が、前記水平断面Ｙ字型の制御棒の中心に向くように配され、
前記ハンドルの上面の上方に配され、前記燃料集合体の上方への浮き上がりを抑制する燃料浮き上がり防止部材を備えることを特徴とする沸騰水型原子炉の炉心。 A core of a boiling water reactor in which fuel assemblies are densely arranged in a triangular lattice arrangement, and a control rod having a Y-shaped horizontal section is inserted in the center of the three fuel assemblies,
In the fuel assembly, the long side or the short side of the upper surface of the handle provided in the three fuel assemblies surrounding the horizontal cross-section Y-shaped control rod faces the center of the horizontal cross-section Y-shaped control rod. Arranged and
A core of a boiling water reactor, comprising a fuel lift prevention member disposed above the upper surface of the handle and suppressing upward lift of the fuel assembly. 請求項１に記載の沸騰水型原子炉の炉心において、
前記燃料浮き上がり防止部材は、三角格子の繰り返しパターン形状を有する格子部材を備えることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 1,
The core of a boiling water reactor, wherein the fuel floating prevention member includes a lattice member having a repetitive pattern shape of a triangular lattice. 請求項２に記載の沸騰水型原子炉の炉心において、
前記ハンドルの上面の長辺と交差する前記格子部材と、前記ハンドルの上面との間に弾性体を設け、前記弾性体の一端が前記ハンドルの上面の長辺と交差する前記格子部材の下面又は前記ハンドルの上面に固定されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 2,
An elastic body is provided between the lattice member that intersects the long side of the upper surface of the handle and the upper surface of the handle, and one end of the elastic body intersects the long side of the upper surface of the handle or the lower surface of the lattice member A boiling water reactor core fixed to an upper surface of the handle. 請求項３に記載の沸騰水型原子炉の炉心において、
前記弾性体は、コイルばね、板ばね、又は竹の子ばねであり、前記燃料集合体を下方へ押圧することを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
The core of a boiling water reactor, wherein the elastic body is a coil spring, a leaf spring, or a bamboo spring, and presses the fuel assembly downward. 請求項３に記載の沸騰水型原子炉の炉心において、
前記格子部材の下面であって、前記ハンドルの上面の長辺と交差する部分に溝又は凹部を備え、前記溝又は凹部の開口幅は前記ハンドルの上面の幅よりも大きく、前記ハンドルの上面が前記弾性体を介して前記溝又は凹部に嵌合することを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
A groove or a recess is provided in a lower surface of the lattice member and intersects with a long side of the upper surface of the handle, the opening width of the groove or the recess is larger than the width of the upper surface of the handle, and the upper surface of the handle is A core of a boiling water reactor, wherein the core is fitted into the groove or the recess through the elastic body. 請求項３に記載の沸騰水型原子炉の炉心において、
前記格子部材の下面であって、前記ハンドルの上面の長辺と交差する部分のうち前記水平断面Ｙ字型の制御棒の中心側から、前記水平断面Ｙ字型の制御棒の中心へと向かう領域に、燃料集合体側へ突出する凸部を有し、前記凸部に前記ハンドルが当接することにより前記燃料集合体が前記水平断面Ｙ字型の制御棒の中心へと向かう変位を規制する燃料集合体変位規制部を備えることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
Of the lower surface of the lattice member, which crosses the long side of the upper surface of the handle, the center of the horizontal cross-section Y-shaped control rod goes to the center of the horizontal cross-section Y-shaped control rod. A fuel having a convex portion projecting toward the fuel assembly side in the region, and restricting displacement of the fuel assembly toward the center of the horizontal cross-section Y-shaped control rod by contacting the convex portion with the handle A core of a boiling water reactor characterized by comprising an assembly displacement regulating section. 請求項３に記載の沸騰水型原子炉の炉心において、
前記格子部材の下面であって、前記ハンドルの上面の長辺と交差する部分以外の領域における垂直断面形状が前記燃料集合体側へ向かうに従い細くなることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
A boiling water nuclear reactor core characterized in that a vertical cross-sectional shape in a region other than a portion of the lower surface of the lattice member intersecting with a long side of the upper surface of the handle becomes narrower toward the fuel assembly side. 請求項３に記載の沸騰水型原子炉の炉心において、
前記格子部材は、前記ハンドルの上面の長辺と交差する部分に前記ハンドルの上面の長辺に対応して延伸する格子拡大部材を有し、前記格子拡大部材の下面と前記ハンドルの上面との間に前記弾性体が配されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
The lattice member has a lattice expansion member that extends in correspondence with the long side of the upper surface of the handle at a portion intersecting with the long side of the upper surface of the handle, and the lower surface of the lattice expansion member and the upper surface of the handle A core of a boiling water reactor, wherein the elastic body is disposed therebetween. 請求項３に記載の沸騰水型原子炉の炉心において、
三角格子を形成する複数の格子部材の接続部が、前記ハンドルの上面の略中央部の上方に位置し、前記複数の格子部材の接続部の下面と前記ハンドルの上面の略中央部との間に前記弾性体が配されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 3,
A connection portion of a plurality of lattice members forming a triangular lattice is located above a substantially central portion of the upper surface of the handle, and is between a lower surface of the connection portions of the plurality of lattice members and a substantially central portion of the upper surface of the handle. A core of a boiling water reactor, characterized in that the elastic body is disposed on the core. 請求項５乃至請求項７のうち、いずれか１項に記載の沸騰水型原子炉の炉心において、
前記格子部材は、前記ハンドルの上面の長辺と交差する部分に前記ハンドルの上面の長辺に対応して延伸する格子拡大部材を有し、前記格子拡大部材の下面と前記ハンドルの上面との間に前記弾性体が配されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to any one of claims 5 to 7,
The lattice member has a lattice expansion member that extends in correspondence with the long side of the upper surface of the handle at a portion intersecting with the long side of the upper surface of the handle, and the lower surface of the lattice expansion member and the upper surface of the handle A core of a boiling water reactor, wherein the elastic body is disposed therebetween. 請求項５又は請求項６に記載の沸騰水型原子炉の炉心において、
前記格子部材の下面であって、前記ハンドルの上面の長辺と交差する部分以外の領域における垂直断面形状が前記燃料集合体側へ向かうに従い細くなることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 5 or 6,
A boiling water nuclear reactor core characterized in that a vertical cross-sectional shape in a region other than a portion of the lower surface of the lattice member intersecting with a long side of the upper surface of the handle becomes narrower toward the fuel assembly side. 請求項５に記載の沸騰水型原子炉の炉心において、
前記格子部材の下面であって、前記ハンドルの上面の長辺と交差する部分のうち前記水平断面Ｙ字型の制御棒の中心側から、前記水平断面Ｙ字型の制御棒の中心へと向かう領域に、燃料集合体側へ突出する凸部を有し、前記凸部に前記ハンドルが当接することにより前記燃料集合体が前記水平断面Ｙ字型の制御棒の中心へと向かう変位を規制する燃料集合体変位規制部を備えることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 5,
Of the lower surface of the lattice member, which crosses the long side of the upper surface of the handle, the center of the horizontal cross-section Y-shaped control rod goes to the center of the horizontal cross-section Y-shaped control rod. A fuel having a convex portion projecting toward the fuel assembly side in the region, and restricting displacement of the fuel assembly toward the center of the horizontal cross-section Y-shaped control rod by contacting the convex portion with the handle A core of a boiling water reactor characterized by comprising an assembly displacement regulating section. 請求項１２に記載の沸騰水型原子炉の炉心において、
前記格子部材は、前記ハンドルの上面の長辺と交差する部分に前記ハンドルの上面の長辺に対応して延伸する格子拡大部材を有し、前記格子拡大部材の下面と前記ハンドルの上面との間に前記弾性体が配されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 12,
The lattice member has a lattice expansion member that extends in correspondence with the long side of the upper surface of the handle at a portion intersecting with the long side of the upper surface of the handle, and the lower surface of the lattice expansion member and the upper surface of the handle A core of a boiling water reactor, wherein the elastic body is disposed therebetween. 請求項１３に記載の沸騰水型原子炉の炉心において、
前記格子部材は、前記ハンドルの上面の長辺と交差する部分に前記ハンドルの上面の長辺に対応して延伸する格子拡大部材を有し、前記格子拡大部材の下面と前記ハンドルの上面との間に前記弾性体が配されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to claim 13,
The lattice member has a lattice expansion member that extends in correspondence with the long side of the upper surface of the handle at a portion intersecting with the long side of the upper surface of the handle, and the lower surface of the lattice expansion member and the upper surface of the handle A core of a boiling water reactor, wherein the elastic body is disposed therebetween. 請求項５乃至請求項８のうち、いずれか１項に記載の沸騰水型原子炉の炉心において、
前記燃料浮き上がり防止部材の最外周部は、内周面に最外周に装荷される燃料集合体と適合する形状を有すると共に炉心の外周に設けられる円環状の炉心支持枠、又は、円筒形状の炉心シュラウドの内周面に設けられる支持部材に固定されることを特徴とする沸騰水型原子炉の炉心。 In the core of the boiling water reactor according to any one of claims 5 to 8,
The outermost peripheral portion of the fuel floating prevention member has a shape that matches the fuel assembly loaded on the outermost periphery on the inner peripheral surface, and an annular core support frame provided on the outer periphery of the core, or a cylindrical core. A core of a boiling water reactor, which is fixed to a support member provided on an inner peripheral surface of a shroud.
JP2016148136A 2016-07-28 2016-07-28 Boiling water reactor Active JP6752072B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2016148136A JP6752072B2 (en) 2016-07-28 2016-07-28 Boiling water reactor
PCT/JP2017/025514 WO2018021044A1 (en) 2016-07-28 2017-07-13 Boiling-water reactor reactor-core

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016148136A JP6752072B2 (en) 2016-07-28 2016-07-28 Boiling water reactor

Publications (2)

Publication Number Publication Date
JP2018017609A true JP2018017609A (en) 2018-02-01
JP6752072B2 JP6752072B2 (en) 2020-09-09

Family

ID=61016506

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016148136A Active JP6752072B2 (en) 2016-07-28 2016-07-28 Boiling water reactor

Country Status (2)

Country Link
JP (1) JP6752072B2 (en)
WO (1) WO2018021044A1 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53118694A (en) * 1977-03-24 1978-10-17 Toshiba Corp Inner construction of reactor
JP3053555B2 (en) * 1995-08-29 2000-06-19 核燃料サイクル開発機構 Ductless fuel assembly holding structure for fast reactors
JP6560861B2 (en) * 2014-12-15 2019-08-14 株式会社日立製作所 Fuel assembly
JP6096834B2 (en) * 2015-06-08 2017-03-15 日立Ｇｅニュークリア・エナジー株式会社 Light water reactor core

Also Published As

Publication number Publication date
WO2018021044A1 (en) 2018-02-01
JP6752072B2 (en) 2020-09-09

Similar Documents

Publication Publication Date Title
US7085340B2 (en) Nuclear reactor fuel assemblies
US4576786A (en) Partial grid for a nuclear reactor fuel assembly
US6421407B1 (en) Nuclear fuel spacer grid with dipper vanes
JPH07198884A (en) Spacer
US11942230B2 (en) Spacer grid using tubular cells
JPH08179070A (en) Fuel assembly for pressurised water reactor
US7889829B2 (en) Nuclear fuel assembly protective grid
KR100789619B1 (en) Four point contact structural spacer grid
US20100310034A1 (en) Nuclear fuel assembly protective bottom grid
JPH07287088A (en) Fuel aggregate of nuclear reactor
JP3328364B2 (en) Low pressure drop spacer for nuclear fuel assemblies
US7804930B2 (en) Nuclear fuel assembly comprising a reinforcing mesh device and the use of one such device in a nuclear fuel assembly
KR100900917B1 (en) Space grid for dual cooling nuclear fuel rods by using a supporting structure at intersection
KR101163998B1 (en) Dual-cooled fuel rod's spacer grids with upper and lower cross-wavy-shape dimple
JP2018017609A (en) Core of boiling water reactor
JPH08170993A (en) Lower tie-plate lattice,fuel-rod supporting structure and nuclear fuel assembly and supporting body for nuclear fuel assembly thereof
US3913689A (en) Core for nuclear reactors
KR20170015986A (en) Crush resistant nuclear fuel assembly support grid
JP7212644B2 (en) boiling water reactor
JP2022175757A (en) Core of boiling-water reactor
KR20130133232A (en) Nuclear fuel rod plenum spring assembly
US9646724B2 (en) Fuel assembly
KR20130077598A (en) Top nozzle assembly to reduce the fuel assembly bow
JP2023037919A (en) Fuel assembly and reactor core
JP7440385B2 (en) fuel assembly

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20181218

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20191217

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200204

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20200609

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200702

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20200811

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20200818

R150 Certificate of patent or registration of utility model

Ref document number: 6752072

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150