JPH09304579A - In-core protective device - Google Patents

In-core protective device

Info

Publication number
JPH09304579A
JPH09304579A JP8125850A JP12585096A JPH09304579A JP H09304579 A JPH09304579 A JP H09304579A JP 8125850 A JP8125850 A JP 8125850A JP 12585096 A JP12585096 A JP 12585096A JP H09304579 A JPH09304579 A JP H09304579A
Authority
JP
Japan
Prior art keywords
core
protection device
cover
core protection
plate
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.)
Pending
Application number
JP8125850A
Other languages
Japanese (ja)
Inventor
Kazuo Sakamaki
和雄 酒巻
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
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 Toshiba Corp filed Critical Toshiba Corp
Priority to JP8125850A priority Critical patent/JPH09304579A/en
Publication of JPH09304579A publication Critical patent/JPH09304579A/en
Pending legal-status Critical Current

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Classifications

    • 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

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  • Monitoring And Testing Of Nuclear Reactors (AREA)

Abstract

PROBLEM TO BE SOLVED: To avoid troublesome recovery work due to fall of foreign articles such as metal into fuel support metal and control rod arranged in the lower part of core and enable performing maintenance work and the like of reactor structure without leading to the degradation of work environment for it. SOLUTION: This device covers the upper surface side of a core support plate 7 appearing after removing fuel assemblies and a plurality of fuel support metal 8 fixed to it in the case of inspection and repair, etc., in a reactor pressure vessel of a boiling water reactor and protects these core support plate 7 and the fuel support metal 8 from falling objects. This is provided with a plurality of cover members 25 hung down through each opening of an upper grid plate. These cover members 25 are spread over the core support plate 7 side by side and are detachably supported with each fuel support metal 8.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、沸騰水型原子炉の
原子炉圧力容器内に設置される制御棒（ＣＲ）や燃料支
持金具（ＦＳ）に定期点検等の際に異物等が落下するこ
とを防止するための炉心保護装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control rod (CR) and a fuel support fitting (FS) installed in a reactor pressure vessel of a boiling water reactor, in which foreign matters and the like fall during periodic inspections. The present invention relates to a core protection device for preventing such a situation.

【０００２】[0002]

【従来の技術】沸騰水型原子炉等の軽水冷却型原子炉で
は、原子炉圧力容器等の内部に設けられる炉内構造物
が、例えばオーステナイト系ステンレス鋼あるいはニッ
ケル基合金のように、高温および高圧の環境下でも十分
な耐蝕性と高温強度とを有する材料によって構成されて
いる。2. Description of the Related Art In a light water cooling type reactor such as a boiling water reactor, the internal structure of the reactor provided inside the reactor pressure vessel, such as austenitic stainless steel or nickel base alloy, is It is made of a material having sufficient corrosion resistance and high temperature strength even under a high pressure environment.

【０００３】しかしながら、交換不能な原子炉内構造物
はプラントの運転により長期間に亘って高温および高圧
の環境に曝されるものであり、しかも炉心材料となる炉
心シュラウド等の場合は中性子照射も受けるため、それ
らが原因となって材料が劣化する可能性がある。特に原
子炉内構造物の溶接部近傍は、溶接入熱による材料の鋭
敏化および引張り応力が残留しているため、潜在的に応
力腐食割れの可能性があると考えられる。However, non-replaceable nuclear reactor internals are exposed to high temperature and high pressure environments for a long period of time during plant operation, and in the case of a core shroud which is a core material, neutron irradiation is also required. As a result, they may cause deterioration of the material. Particularly in the vicinity of the welded portion of the internal structure of the nuclear reactor, the sensitization of the material and the tensile stress due to the heat input of the welding remain, and it is considered that there is a possibility of stress corrosion cracking.

【０００４】ところで最近、各種プラントの運転期間の
長期化に対応し、予防保全技術対策として種々の材料表
面改質技術の開発が行われている。その一環として表面
残留応力を積極的に引張りから圧縮に変えることによっ
て応力腐食割れを未然に防止するための対策工法の開
発、例えばショットピーニングあるいはウォータジェッ
トピーニング等による表面残留応力改善技術の開発が行
われている。By the way, recently, various material surface modification techniques have been developed as countermeasures for preventive maintenance techniques in response to the prolongation of the operation period of various plants. As part of this, the development of a countermeasure method to prevent stress corrosion cracking by positively changing the surface residual stress from tension to compression, for example, development of surface residual stress improvement technology by shot peening or water jet peening. It is being appreciated.

【０００５】ショットピーニングでは、直径０．３〜
１．２mm程度の鋼球からなるショット球を、高圧空気あ
るいは遠心力を利用して加速し、ショット球の運動エネ
ルギにより施行部表面を塑性変形させることにより表面
に圧縮残留応力を形成する技術である。In shot peening, the diameter is 0.3 to
This is a technology that forms a compressive residual stress on the surface by accelerating a shot ball consisting of a steel ball of about 1.2 mm using high pressure air or centrifugal force and plastically deforming the surface of the applied part by the kinetic energy of the shot ball. is there.

【０００６】また、ウォータジェットピーニングは、１
０００気圧程度の超高圧水をノズル先端から噴射し、水
撃作用およびキャビテーションが破壊する際の衝撃波に
よって表面に圧縮応力を形成する技術である。いずれも
水中での施工により応力腐食割れ等に対する有効性が実
証され、一部実用化されている。Water jet peening is 1
This is a technique in which ultra-high pressure water of about 000 atm is jetted from the tip of a nozzle, and a compressive stress is formed on the surface by a shock wave when a water hammer action and cavitation break. All of them have been proved to be effective against stress corrosion cracking by construction in water and have been partially put into practical use.

【０００７】[0007]

【発明が解決しようとする課題】そこで、このようなシ
ョットピーニングやウォータジェットピーニング等の技
術を用い、原子炉内構造物の炉心シュラウド等の表面残
留応力を改善することが考えられる。Therefore, it is conceivable to improve the surface residual stress of the core shroud of the reactor internal structure by using such techniques as shot peening and water jet peening.

【０００８】ところが、ショットピーニングやウォータ
ジェットピーニング等を適用した場合には、ショットピ
ーニングの際に噴出した鋼球であるショット球や、超高
圧水によって原子炉構造物表面の錆や剥離金属等の異物
が施工箇所の周囲に飛散することが考えられる。原子炉
構造物の保全作業等は、原子炉圧力容器の炉心部から燃
料集合体を移動した後に行われるので、炉心下方に配置
されている燃料支持金具や、同位置に配置されている制
御棒駆動機構等に金属等の異物が落下して、作業環境が
悪化し面倒な回収作業が必要となる等の不具合を来す可
能性が考えられる。However, when shot peening, water jet peening or the like is applied, shot spheres which are steel balls ejected during shot peening, rust on the surface of the nuclear reactor structure due to ultra high pressure water, peeling metal, etc. It is conceivable that foreign matter will be scattered around the construction site. Maintenance work of the reactor structure is performed after moving the fuel assembly from the core of the reactor pressure vessel.Therefore, fuel support fittings located below the core and control rods located at the same position. It is conceivable that foreign matter such as metal may fall onto the drive mechanism or the like, resulting in a bad working environment and requiring troublesome collection work.

【０００９】本発明はこのような事情に鑑みてなされた
ものであり、炉心下方に配置されている燃料支持金具
や、同位置に配置されている制御棒等に金属等の異物が
落下して、面倒な回収作業を不要とすることができ、そ
れにより作業環境の悪化を招くことなく原子炉構造物の
保全作業等を行うことを可能とする炉心保護装置を提供
することを目的とする。The present invention has been made in view of the above circumstances, and foreign matter such as a metal is dropped onto a fuel support fitting arranged below the core, a control rod arranged at the same position, or the like. An object of the present invention is to provide a reactor core protection device that can eliminate troublesome recovery work and can perform maintenance work of a nuclear reactor structure without deteriorating the working environment.

【００１０】[0010]

【課題を解決するための手段】前記の目的を達成するた
めに、請求項１の発明は、沸騰水型原子炉の原子炉圧力
容器内の点検、補修等に際し、燃料集合体を移動した後
に表出する炉心支持板およびこれに取付けた複数の燃料
支持金具の上面側を被覆して、これら炉心支持板および
燃料支持金具を落下物から保護する炉心内保護装置であ
って、上部格子板の各開口部を通して吊り下ろされる複
数のカバー部材を備え、これらのカバー部材を互いに隣
接させて前記炉心支持板上に敷き詰めるとともに、これ
らのカバー部材を前記各燃料支持金具にそれぞれ着脱可
能に支持させてなることを特徴とする。In order to achieve the above-mentioned object, the invention of claim 1 is, after the fuel assembly is moved, at the time of inspection and repair in the reactor pressure vessel of the boiling water reactor. An in-core protection device for covering the exposed core support plate and the upper surface side of a plurality of fuel support fittings attached thereto to protect the core support plate and the fuel support fittings from falling objects, A plurality of cover members are hung through the respective openings, the cover members are laid adjacent to each other on the core support plate, and the cover members are detachably supported by the respective fuel support fittings. It is characterized by

【００１１】請求項２の発明は、請求項１記載の炉心内
保護装置において、カバー部材は燃料支持金具の上に載
置されるブロック状のカバー本体と、このカバー本体の
上壁部にこれよりも幅広く設けられ相互に他のものと重
合する弾性材製の被覆板とを有する構成とされているこ
とを特徴とする。According to a second aspect of the present invention, in the in-core protection device according to the first aspect, the cover member is a block-shaped cover body placed on the fuel support fitting, and the cover body is provided on the upper wall portion of the cover body. It is characterized in that it is provided with a wider range and has a cover plate made of an elastic material which is superposed on each other.

【００１２】請求項３の発明は、請求項２記載の炉心内
保護装置において、カバー部材の上部には吊り下げ操作
用のハンドルを設けたことを特徴とする。According to a third aspect of the present invention, in the in-core protection device according to the second aspect, a handle for suspending operation is provided on an upper portion of the cover member.

【００１３】請求項４の発明は、請求項１から３までの
いずれかに記載の炉心内保護装置において、カバー本体
の下端部には燃料支持金具の冷却水流路部に上方から挿
入される位置決め用の脚部を設けたことを特徴とする。According to a fourth aspect of the invention, in the core protecting apparatus according to any one of the first to third aspects, the lower end portion of the cover body is positioned so as to be inserted into the cooling water passage portion of the fuel support fitting from above. It is characterized by having legs for use.

【００１４】請求項５の発明は、請求項１から４までの
いずれかに記載の炉心内保護装置において、カバー本体
の上部に空気抜き孔を設けたことを特徴とする。According to a fifth aspect of the present invention, in the core protecting apparatus according to any one of the first to fourth aspects, an air vent hole is provided in an upper portion of the cover body.

【００１５】請求項６の発明は、請求項１から５までの
いずれかに記載の炉心内保護装置において、カバー部材
の周壁部には、被覆板を通過する金属性の落下物を吸着
させて停止保持するためのマグネットを設けたことを特
徴とする。According to a sixth aspect of the present invention, in the in-core protection device according to any of the first to fifth aspects, the peripheral wall portion of the cover member is made to adsorb metallic fallen objects passing through the covering plate. It is characterized in that a magnet for stopping and holding is provided.

【００１６】請求項７の発明は、請求項１から６までの
いずれかに記載の炉心内保護装置において、各被覆板は
輪郭部分に段差部を有し、隣接する他の被覆板の輪郭部
分と相互に重合可能であることを特徴とする。According to a seventh aspect of the invention, in the in-core protection device according to any of the first to sixth aspects, each cover plate has a step portion in the contour portion, and the contour portions of other adjacent cover plates are provided. And are mutually polymerizable.

【００１７】[0017]

【発明の実施の形態】以下、本発明に係る炉心保護装置
の一実施形態について、図１〜図７を参照して説明す
る。なお、本実施形態は改良型沸騰水型原子炉（ＡＢＷ
Ｒ）に適用した場合についてのものである。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a core protection device according to the present invention will be described below with reference to FIGS. The present embodiment is an improved boiling water reactor (ABW).
R) is applied.

【００１８】まず、図５〜図７によって改良型沸騰水型
原子炉の原子炉圧力容器の概略構成を説明する。図５は
全体構成を示す断面図であり、図６は燃料支持部の拡大
図であり、図７は同部分の平面図である。First, the schematic construction of the reactor pressure vessel of the improved boiling water reactor will be described with reference to FIGS. 5 is a cross-sectional view showing the overall structure, FIG. 6 is an enlarged view of the fuel support portion, and FIG. 7 is a plan view of the same portion.

【００１９】図５に示すように、原子炉圧力容器１内の
中心位置に炉心シュラウド２が設置され、この炉心シュ
ラウド２の内部に多数の燃料集合体３および制御棒４が
収納されて炉心５が形成されている。すなわち、炉心シ
ュラウド２の上部には上部格子板６が、また下部には炉
心支持板７がそれぞれ設けられ、燃料集合体３の上端部
が上部格子板６によって支持されるとともに、燃料集合
体３の下端部が図６に示すように、炉心支持板７上の燃
料支持金具８によって支持されている。As shown in FIG. 5, a core shroud 2 is installed at a central position in a reactor pressure vessel 1, and a large number of fuel assemblies 3 and control rods 4 are housed in the core shroud 2 to form a core 5. Are formed. That is, an upper lattice plate 6 is provided above the core shroud 2 and a core support plate 7 is provided below the core shroud 2. The upper end of the fuel assembly 3 is supported by the upper lattice plate 6 and the fuel assembly 3 As shown in FIG. 6, the lower end portion of is supported by the fuel support fitting 8 on the core support plate 7.

【００２０】制御棒４は、横断面十字状羽根構造をな
し、図７に示すように、４本１組の燃料集合体３の十字
状隙間に挿入されており、炉心シュラウド２の下方に設
置された制御棒案内管９内に挿通されて、原子炉圧力容
器１の下面を貫通した制御棒駆動機構１０により上下方
向に駆動されるようになっている。なお、制御棒４の上
端には吊り下げ操作用の略コ字形のハンドル１７が突設
してある。The control rod 4 has a cross-shaped vane structure in cross section, and is inserted into the cross-shaped gap of a set of four fuel assemblies 3 as shown in FIG. 7, and is installed below the core shroud 2. It is adapted to be vertically driven by a control rod drive mechanism 10 which is inserted through the control rod guide tube 9 and which penetrates the lower surface of the reactor pressure vessel 1. A substantially U-shaped handle 17 for suspending operation is provided on the upper end of the control rod 4 so as to project therefrom.

【００２１】また、炉心５内には中性子源領域モニタ
（ＳＲＭ）、中間領域モニタ（ＩＲＭ）、局部領域モニ
タ（ＬＰＲＭ）などの計測管１１が分散配置され、炉心
各部の出力分布を監視するようになっている。なお、炉
心シュラウド２の上端にはシュラウドヘッド１２が取り
付けられ、このシュラウドヘッド１２の上方に気水分離
器１３および蒸気乾燥器１４が順次に設けられている。
原子炉圧力容器１の上端開口は圧力容器蓋１５により閉
塞されている。そして、原子炉運転時には、原子炉圧力
容器１の下部に設けたインターナルポンプ１６によって
冷却水を循環させるとともに、制御棒９を制御棒駆動機
構１０によって上下に駆動することで出力制御を行うよ
うになっている。Further, measuring pipes 11 such as a neutron source region monitor (SRM), an intermediate region monitor (IRM) and a local region monitor (LPRM) are arranged in the core 5 in a distributed manner so as to monitor the output distribution of each part of the core. It has become. A shroud head 12 is attached to the upper end of the core shroud 2, and a steam separator 13 and a steam dryer 14 are sequentially provided above the shroud head 12.
The upper end opening of the reactor pressure vessel 1 is closed by a pressure vessel lid 15. Then, during the reactor operation, the cooling water is circulated by the internal pump 16 provided in the lower part of the reactor pressure vessel 1, and the control rod 9 is driven up and down by the control rod drive mechanism 10 to perform the output control. It has become.

【００２２】一方、定期点検時においては、原子炉運転
を停止し、図示しない原子炉格納容器のカバーを取外し
た後、圧力容器蓋１５を取外し、さらに上記乾燥器１
４、気水分離器１３、シュラウドヘッド１２等を取外
し、この状態で燃料集合体３を上方に抜出して原子炉ピ
ットに移動し、制御棒４を最大限下方に移動させた状態
とする。この状態で、例えば炉心シュラウド２の内面等
の検査、あるいは保全作業等としてのショットピーニン
グ等を実施するものであるが、このショットピーニング
等の際に、炉心シュラウド２に衝突したショット球や、
炉心シュラウドの錆等の金属性の異物が炉心下方に落下
し、炉心支持板７上の燃料支持金具８等に付着する可能
性がある。On the other hand, at the time of periodic inspection, the reactor operation is stopped, the cover of the reactor containment vessel (not shown) is removed, the pressure vessel lid 15 is removed, and the dryer 1 is further removed.
4, the steam separator 13, the shroud head 12 and the like are removed, and in this state, the fuel assembly 3 is extracted upward and moved to the reactor pit, and the control rod 4 is moved downward as much as possible. In this state, for example, inspection of the inner surface of the core shroud 2 or shot peening as maintenance work is performed. At the time of this shot peening, shot balls that collide with the core shroud 2,
There is a possibility that metallic foreign matter such as rust in the core shroud may fall below the core and adhere to the fuel support fittings 8 and the like on the core support plate 7.

【００２３】本実施形態の炉心保護装置は、このような
落下物を発生させる可能性がある保全作業等に先立っ
て、炉心支持板７上の燃料支持金具８および制御棒４の
上方を被覆し、これらを落下物から保護するためのもの
である。以下、図１〜図４によって炉心保護装置２１の
構成および作用等について説明する。The core protection device of this embodiment covers the fuel support fitting 8 on the core support plate 7 and the upper part of the control rod 4 prior to the maintenance work or the like that may generate such fallen objects. , To protect these from falling objects. Hereinafter, the configuration, operation, and the like of the core protection device 21 will be described with reference to FIGS.

【００２４】図１は一部に炉心保護装置２１（後述する
被覆板を仮想線で示している）を装着して炉心５を上部
格子板６の上方から見た状態で示す平面図である。な
お、この図１では、格子状配置で隣接する４個の燃料支
持金具８のうち、対角線（Ａ−Ａ線）上で隣接する２個
の燃料支持金具８（８ａ，８ｂ）を、それぞれ炉心内保
護装置２１で被覆した状態を示している（残る交差方向
の他の２個の燃料支持金具８（８ｃ，８ｄ）について
は、炉心内保護装置で被覆していない状態を示してい
る）。図２は図１のＡ−Ａ矢視断面図であり、炉心内保
護装置２１で被覆した２個の燃料支持金具８ａ，８ｂの
縦断面を示している。図３は図２の平面図で、ある。図
４は炉心内保護装置の取付けおよび取外し等の作用を説
明するための概略断面図である。FIG. 1 is a plan view showing a state in which a core protection device 21 (a cover plate which will be described later is shown in phantom lines) is partially mounted and the core 5 is viewed from above the upper lattice plate 6. In FIG. 1, of the four fuel support fittings 8 adjacent to each other in a grid arrangement, two fuel support fittings 8 (8a, 8b) adjacent on a diagonal line (A-A line) are respectively connected to the core. It shows a state in which it is covered by the inner protection device 21 (the other two fuel support fittings 8 (8c, 8d) in the intersecting direction that remain are shown not covered by the in-core protection device). FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and shows a vertical cross section of the two fuel support fittings 8a and 8b covered with the in-core protection device 21. FIG. 3 is a plan view of FIG. FIG. 4 is a schematic cross-sectional view for explaining the operations such as attachment and detachment of the core protection device.

【００２５】各燃料支持金具８は図１および図２に示す
ように、上部格子板６の各開口部６ａに対応する平面配
置とされており、それぞれ制御棒４を挿通したリング状
のフレーム２２の４か所に等間隔で燃料集合体４の下端
部を支持する円筒状の冷却水流路部２３を周配した構成
のものである。As shown in FIGS. 1 and 2, the fuel support fittings 8 are arranged in a plane corresponding to the openings 6a of the upper lattice plate 6, and the ring-shaped frame 22 into which the control rods 4 are inserted. The cylindrical cooling water flow path 23 that supports the lower end of the fuel assembly 4 is evenly arranged at four positions.

【００２６】そして、本実施形態の炉心保護装置２１
は、上部格子板６の各開口部６ａを通して吊り下ろされ
る複数のカバー部材２４を備え、これらのカバー部材２
４を互いに隣接させて炉心支持板７上に敷き詰めるとと
もに、これらのカバー部材２４を各燃料支持金具８にそ
れぞれ着脱可能に支持させるようになっている。The core protection device 21 of the present embodiment
Comprises a plurality of cover members 24 suspended through the openings 6a of the upper grid plate 6, and these cover members 2
4 are arranged adjacent to each other on the core support plate 7, and these cover members 24 are detachably supported by the respective fuel support fittings 8.

【００２７】すなわち、各カバー部材２４は燃料支持金
具８の上に載置されるブロック状のカバー本体２５と、
このカバー本体２５の上壁部にこれよりも幅広く設けら
れ、相互に他のものと重合する弾性材、例えばゴム製の
被覆板２６とを有する構成とされている。That is, each cover member 24 is a block-shaped cover body 25 placed on the fuel support fitting 8,
The cover main body 25 has an upper wall portion wider than the upper wall portion, and has an elastic material, such as a rubber cover plate 26, which is capable of superposing on each other.

【００２８】カバー本体２５は図１、図２および図３に
示すように、平面形状が上部格子板６の各開口部６ａよ
りも若干小さい角形をした箱状のものであり、上側隅角
部が面取りされ、また下端壁には制御棒を囲むことがで
きる大きさの孔を形成してある。そして、このカバー本
体２５は丁度、燃料支持金具８の上に載置できるように
なっている。このカバー本体２５の下端部に例えば対角
配置で１対の脚部２７が下向きに突設され、これらの各
脚部２７が燃料支持金具８の対角線上にある冷却水流路
部２３に上方から着脱可能に挿入され、これによってカ
バー本体２５が燃料支持金具８の上で位置決されるとと
もに、載置後に転倒等を防止できるようになっている。
なお、脚部２７は冷却水流路部２３の数に対応して４本
設けてもよい。また、場合によっては１本、あるいは３
本としてもよい。要するに位置決めおよび載置後の安定
化が図れるものであればよい。As shown in FIGS. 1, 2 and 3, the cover main body 25 is a box-shaped one having a rectangular shape whose plane shape is slightly smaller than each opening 6a of the upper lattice plate 6, and has an upper corner portion. Is chamfered, and a hole is formed in the lower end wall of a size large enough to surround the control rod. The cover body 25 can be placed directly on the fuel support fitting 8. For example, a pair of leg portions 27 are projected downward at a lower end portion of the cover main body 25 in a diagonal arrangement, and each of these leg portions 27 is inserted into the cooling water passage portion 23 on the diagonal line of the fuel support fitting 8 from above. The cover main body 25 is removably inserted so that the cover main body 25 is positioned on the fuel support metal fitting 8 and it is possible to prevent the cover body 25 from falling over after being placed.
Note that four leg portions 27 may be provided in correspondence with the number of cooling water flow passage portions 23. Also, depending on the case, 1 or 3
It may be a book. In short, it is sufficient if the positioning and the stabilization after mounting can be achieved.

【００２９】被覆板２６は、上部格子板６の各開口部６
ａよりも若干大きい四角形とされており、カバー本体２
５の上面壁の上面に一体的に固着されている。この被覆
板２６はカバー部材２４を上部格子板６の開口部６ａに
通す際、弾性的に撓むことによって、その開口部６ａを
通過することができる。この被覆板２６には、カバー本
体２５の上部に突出した吊り下げ操作用のハンドル２８
が貫通している。このハンドル２８は、制御棒４のハン
ドル１７と略同一形状のものである。このハンドル２８
をクレーン等のワイヤで吊ることによって、炉心内に設
置する場合の移動操作が行われるものである。この被覆
板２６の輪郭部分には一段高くなった段差部２９が形成
され、隣接する他の被覆板２６の輪郭部分の段差部２９
と相互に重合可能となっている。The cover plate 26 is formed in each opening 6 of the upper grid plate 6.
The cover body 2 has a rectangular shape slightly larger than a.
It is integrally fixed to the upper surface of the upper surface wall of 5. When the cover member 24 is passed through the opening 6a of the upper lattice plate 6, the cover plate 26 can elastically bend to pass through the opening 6a. The cover plate 26 has a handle 28 for suspending operation, which protrudes above the cover body 25.
Has penetrated. The handle 28 has substantially the same shape as the handle 17 of the control rod 4. This handle 28
The operation is carried out when it is installed in the core by suspending the wire with a wire such as a crane. A step portion 29 that is one step higher is formed in the contour portion of the cover plate 26, and the step portion 29 of the contour portion of another adjacent cover plate 26 is formed.
It is possible to polymerize with each other.

【００３０】また、カバー本体２５の上部には複数の空
気抜き孔３０が設けられ、カバー部材２４を空中から冷
却水内に吊り下す際に、カバー本体２５内の空気が空気
抜き孔３０から抜けて円滑に吊り下しを行えるようにな
っている。Further, a plurality of air vent holes 30 are provided in the upper portion of the cover body 25, and when the cover member 24 is suspended from the air into the cooling water, the air in the cover body 25 escapes from the air vent holes 30 and is smooth. It can be hung on the ground.

【００３１】さらに、カバー本体２５の周壁部内面側に
は、複数のマグネット３１が設けられ、被覆板２６を通
過して落下する金属性の落下物をカバー本体２５の周壁
外面に吸着させて停止保持できるようになっている。Further, a plurality of magnets 31 are provided on the inner surface side of the peripheral wall portion of the cover main body 25, and a metal fallen object that passes through the cover plate 26 and falls is attracted to the outer peripheral wall surface of the cover main body 25 and stopped. It can be held.

【００３２】次に上記実施形態の作用について説明す
る。Next, the operation of the above embodiment will be described.

【００３３】原子炉の定期点検、保全時等の際には前述
したように、燃料集合体３を炉心５から取り外して移動
する。その際、制御棒４は制御棒案内管９内に引き下
げ、通常炉水位は上部格子板６から約１５ｍ以上の水位
を保つようにする。つまり、原子炉ウェル（図示せず）
の満水状態で作業が行われる。At the time of periodic inspection and maintenance of the nuclear reactor, the fuel assembly 3 is removed from the core 5 and moved as described above. At that time, the control rod 4 is pulled down into the control rod guide tube 9 so that the normal reactor water level is maintained at a water level of about 15 m or more from the upper lattice plate 6. That is, the reactor well (not shown)
The work is carried out in a full state.

【００３４】この状態で、本実施形態の炉心保護装置２
１を設置する。この場合、まず、図４に示すように、燃
料取替え機３２を移動し、それに合せて補助ホイスト３
３も移動し、この補助ホイスト３３の吊りワイヤ３４の
先端に掴み具３５を連結する。この掴み具３５のシリン
ダにエア圧を供給し、フックを開閉させてカバー部材２
４のハンドル２８を把持し、上部格子板６の開口部６ａ
を通して下方に吊り下す。上部格子板６の開口部６ａの
下方には前述したように、燃料支持金具８が配置してい
るので、カバー部材２４を燃料支持金具８上に載置する
ことができる。In this state, the core protection device 2 of this embodiment
1 is set. In this case, first, as shown in FIG. 4, the refueling machine 32 is moved and the auxiliary hoist 3 is moved accordingly.
3 also moves, and the grasping tool 35 is connected to the tip of the suspension wire 34 of the auxiliary hoist 33. Air pressure is supplied to the cylinder of the grip 35 to open and close the hook to cover the cover member 2
4 grips the handle 28 and the opening 6a of the upper lattice plate 6
Hang down through. As described above, the fuel support fitting 8 is arranged below the opening 6a of the upper grid plate 6, so that the cover member 24 can be placed on the fuel support fitting 8.

【００３５】この場合、図２に示したように、カバー部
材２４の下端に突出する脚部２７が燃料支持金具８の冷
却水流路部２３に挿入されることによって位置決めおよ
び載置状態の安定化が図られる。In this case, as shown in FIG. 2, the leg portion 27 projecting from the lower end of the cover member 24 is inserted into the cooling water flow passage portion 23 of the fuel support fitting 8 to stabilize the positioning and placement state. Is planned.

【００３６】同様にして、他のカバー部材２４を炉心内
に順次に設置し、これによって炉心支持板７上にカバー
部材２４を敷き詰めて、炉心支持板７の前面を被覆する
ことができる。なお、被覆板２６の輪郭部分は段差部２
９が相互に重複するので、隙間ない被覆状態が得られ
る。また、図２に示したように、上部格子板の交差部下
方に位置して、計測管１１がインコア案内管１１ａで支
持されて柱状に設置されているが、被覆板２６の段差部
２９の撓みによって、その計測管１１の周囲部を隙間な
く被覆することができる。Similarly, the other cover members 24 can be sequentially installed in the core, whereby the cover members 24 can be spread over the core support plate 7 to cover the front surface of the core support plate 7. In addition, the contour portion of the cover plate 26 has a step portion 2
Since 9 overlap with each other, a covered state with no gap is obtained. Further, as shown in FIG. 2, the measuring pipe 11 is positioned below the intersection of the upper grid plate and is installed in a columnar shape supported by the in-core guide pipe 11a. Due to the bending, the peripheral portion of the measuring pipe 11 can be covered without a gap.

【００３７】以上のようにして炉心内保護装置２１の取
り付け作業が終了したら、所定の保全工事を行う。例え
ば炉心シュラウド２の内面のショットピーニング等を行
う場合には、炉心内に炉心内保護装置２１を全面的に設
置する。これにより、炉心内保護装置２１で炉心支持板
７および炉心支持金具８の上面を全面的に被覆すること
で、ショットピーニング球や、炉心シュラウド２から剥
離した錆等の異物、すなわち金属落下物が発生しても、
これらの異物を炉心内保護装置２１の上面の被覆板２６
上で捕獲することができ、制御棒駆動機構１０内に異物
が入り込まないよう、予防保全対策を講じることができ
る。When the installation work of the in-core protection device 21 is completed as described above, predetermined maintenance work is performed. For example, when performing shot peening or the like on the inner surface of the core shroud 2, the in-core protection device 21 is entirely installed in the core. As a result, by covering the upper surfaces of the core support plate 7 and the core support fittings 8 with the in-core protection device 21 completely, shot peening balls and foreign substances such as rust peeled off from the core shroud 2, that is, metal falling objects. Even if it occurs
These foreign matters are covered by the coating plate 26 on the upper surface of the core protection device 21.
It can be captured above and preventive maintenance measures can be taken to prevent foreign objects from entering the control rod drive mechanism 10.

【００３８】以上の本実施形態によれば、炉心５内の燃
料支持金具８の上面およびその隣接する隙間部を全面に
覆うことにより、異物等の挿入、落下がなく、安全に作
業を行うことができる。しかも、カバー部材２４の上面
は全面に亘って被覆板２６で覆われた状態とすることで
平面構造となっているため、異物等が上面に落下した場
合でも容易に回収することができる。According to the present embodiment described above, by covering the upper surface of the fuel support metal fitting 8 in the core 5 and the gap portion adjacent to the entire surface, foreign matter and the like are not inserted or dropped, and the work can be performed safely. You can Moreover, since the entire upper surface of the cover member 24 is covered with the cover plate 26 to have a planar structure, even if foreign matter or the like falls onto the upper surface, it can be easily collected.

【００３９】なお、金属性の異物が被覆板２６の輪郭部
の重合部分を通って落下する可能性があるが、この場合
にはカバー本体２４内に設けたマグネット３１の作用に
よって、異物をカバー本体２４の外側部で吸引して保持
することができる。この保持された異物は、作業終了後
に炉心内保護装置２１を吊り上げて回収することができ
る。There is a possibility that the metallic foreign matter will fall through the overlapping portion of the outline of the cover plate 26. In this case, the magnet 31 provided inside the cover body 24 acts to cover the foreign matter. It can be sucked and held on the outer side of the body 24. The retained foreign matter can be collected by lifting the in-core protection device 21 after the work is completed.

【００４０】[0040]

【発明の効果】以上で詳述したように、本発明によれ
ば、原子炉の定期点検等の際に行われる炉心内保全作業
等において、制御棒や燃料支持金具内方への異物等の落
下を防止することができ、また万一、落下した場合でも
回収を容易に行うことができ、ひいては作業員の放射線
被曝量を大幅に低減させることができる等、優れた効果
が奏される。As described above in detail, according to the present invention, in the core maintenance work, etc., which is carried out at the time of periodic inspection of the nuclear reactor, foreign matter etc. inside the control rods and the fuel support fittings can be prevented. It is possible to prevent falling, and even if it should fall, it is possible to easily collect it, and it is possible to greatly reduce the radiation exposure dose of the worker.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明に係る炉心内保護装置の一実施形態を示
す図平面図。FIG. 1 is a schematic plan view showing an embodiment of a core protection device according to the present invention.

【図２】図１のＡ−Ａ線矢視断面図。FIG. 2 is a sectional view taken along the line AA of FIG.

【図３】図３の平面図。FIG. 3 is a plan view of FIG.

【図４】本発明に係る炉心内保護装置の一実施形態を示
す図で、使用状態を説明するための概略断面図。FIG. 4 is a diagram showing an embodiment of the in-core protection device according to the present invention, and is a schematic cross-sectional view for explaining a usage state.

【図５】沸騰水型原子炉を示す縦断面図。FIG. 5 is a vertical cross-sectional view showing a boiling water reactor.

【図６】図５における炉心の一部を示す拡大断面図。FIG. 6 is an enlarged cross-sectional view showing a part of the core in FIG.

【図７】図６における炉心の一部を示す平面図。FIG. 7 is a plan view showing a part of the core in FIG.

【符号の説明】[Explanation of symbols]

１ 原子炉圧力容器 ２ 炉心シュラウド ３ 燃料集合体 ４ 制御棒 ５ 炉心 ６ 上部格子板 ７ 炉心支持板 ８ 燃料支持金具 ９ 制御棒案内管 １０ 制御棒駆動機構 １１ 計測管 １２ シュラウドヘッド １３ 気水分離器 １４ 蒸気乾燥器 １５ 圧力容器蓋 １６ インターナルポンプ １７ ハンドル ２１ 炉心保護装置 ２２ フレーム ２３ 冷却水流路部 ２４ カバー部材 ２５ カバー本体 ２６ 被覆板 ２７ 脚部 ２８ ハンドル ２９ 段差部 ３０ 空気抜き孔 ３１ マグネット ３２ 燃料取替え機 ３３ 補助ホイスト ３４ 吊りワイヤ ３５ 掴み具 1 Reactor Pressure Vessel 2 Core Shroud 3 Fuel Assembly 4 Control Rod 5 Core 6 Upper Lattice Plate 7 Core Support Plate 8 Fuel Support Fitting 9 Control Rod Guide Tube 10 Control Rod Drive Mechanism 11 Measurement Pipe 12 Shroud Head 13 Water-Water Separator 14 Steam Dryer 15 Pressure Vessel Lid 16 Internal Pump 17 Handle 21 Core Protection Device 22 Frame 23 Cooling Water Flow Path 24 Cover Member 25 Cover Main Body 26 Cover Plate 27 Leg 28 Handle 29 Step Difference 30 Air Vent Hole 31 Magnet 32 Fuel Replacement Machine 33 Auxiliary hoist 34 Hanging wire 35 Grasping tool

Claims (7)

【特許請求の範囲】[Claims] 【請求項１】 沸騰水型原子炉の原子炉圧力容器内の点
検、補修等に際し、燃料集合体を移動した後に表出する
炉心支持板およびこれに取付けた複数の燃料支持金具の
上面側を被覆して、これら炉心支持板および燃料支持金
具を落下物から保護する炉心内保護装置であって、上部
格子板の各開口部を通して吊り下ろされる複数のカバー
部材を備え、これらのカバー部材を互いに隣接させて前
記炉心支持板上に敷き詰めるとともに、これらのカバー
部材を前記各燃料支持金具にそれぞれ着脱可能に支持さ
せてなることを特徴とする炉心内保護装置。1. A core support plate and an upper surface side of a plurality of fuel support fittings attached to the core support plate which are exposed after moving a fuel assembly at the time of inspection, repair, etc. in a reactor pressure vessel of a boiling water reactor. An in-core protection device that covers and protects the core support plate and the fuel support fittings from falling objects, and includes a plurality of cover members that are hung through the openings of the upper lattice plate, and these cover members are mutually An in-core protection device, which is spread adjacently on the core support plate and detachably supports these cover members on the respective fuel support fittings. 【請求項２】 請求項１記載の炉心内保護装置におい
て、カバー部材は燃料支持金具の上に載置されるブロッ
ク状のカバー本体と、このカバー本体の上壁部にこれよ
りも幅広く設けられ相互に他のものと重合する弾性材製
の被覆板とを有する構成とされていることを特徴とする
炉心内保護装置。2. The in-core protection device according to claim 1, wherein the cover member is a block-shaped cover body placed on the fuel support fitting, and the cover body is provided on the upper wall portion of the cover body wider than the block body. An in-core protection device having a structure including a cover plate made of an elastic material which is superposed on each other. 【請求項３】 請求項２記載の炉心内保護装置におい
て、カバー部材の上部には吊り下げ操作用のハンドルを
設けたことを特徴とする炉心内保護装置。3. The in-core protection device according to claim 2, wherein a handle for suspending operation is provided on an upper portion of the cover member. 【請求項４】 請求項１から３までのいずれかに記載の
炉心内保護装置において、カバー本体の下端部には燃料
支持金具の冷却水流路部に上方から挿入される位置決め
用の脚部を設けたことを特徴とする炉心内保護装置。4. The in-core protection device according to any one of claims 1 to 3, wherein a lower end portion of the cover body is provided with a positioning leg portion which is inserted into a cooling water flow passage portion of the fuel support fitting from above. An in-core protection device characterized by being provided. 【請求項５】 請求項１から４までのいずれかに記載の
炉心内保護装置において、カバー本体の上部に空気抜き
孔を設けたことを特徴とする炉心内保護装置。5. The in-core protection device according to any one of claims 1 to 4, wherein an air vent hole is provided in an upper portion of the cover body. 【請求項６】 請求項１から５までのいずれかに記載の
炉心内保護装置において、カバー部材の周壁部には、被
覆板を通過する金属性の落下物を吸着させて停止保持す
るためのマグネットを設けたことを特徴とする炉心内保
護装置。6. The in-core protection device according to any one of claims 1 to 5, wherein a peripheral wall portion of the cover member adsorbs a metal fallen object passing through the cover plate and holds it. An in-core protection device characterized by having a magnet. 【請求項７】 請求項１から６までのいずれかに記載の
炉心内保護装置において、各被覆板は輪郭部分に段差部
を有し、隣接する他の被覆板の輪郭部分と相互に重合可
能であることを特徴とする炉心内保護装置。7. The in-core protection device according to any one of claims 1 to 6, wherein each cover plate has a step portion in a contour portion and can overlap with a contour portion of another adjacent cover plate. In-core protection device characterized by:
JP8125850A 1996-05-21 1996-05-21 In-core protective device Pending JPH09304579A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8125850A JPH09304579A (en) 1996-05-21 1996-05-21 In-core protective device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8125850A JPH09304579A (en) 1996-05-21 1996-05-21 In-core protective device

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JPH09304579A true JPH09304579A (en) 1997-11-28

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JP8125850A Pending JPH09304579A (en) 1996-05-21 1996-05-21 In-core protective device

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109411101A (en) * 2018-11-30 2019-03-01 上海核工程研究设计院有限公司 A kind of fixed structure of in-pile component guide cylinder

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109411101A (en) * 2018-11-30 2019-03-01 上海核工程研究设计院有限公司 A kind of fixed structure of in-pile component guide cylinder

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