JP3774600B2 - Replacement method of neutron measurement housing and apparatus used therefor - Google Patents

Replacement method of neutron measurement housing and apparatus used therefor Download PDF

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JP3774600B2
JP3774600B2 JP28768699A JP28768699A JP3774600B2 JP 3774600 B2 JP3774600 B2 JP 3774600B2 JP 28768699 A JP28768699 A JP 28768699A JP 28768699 A JP28768699 A JP 28768699A JP 3774600 B2 JP3774600 B2 JP 3774600B2
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neutron
housing
neutron measurement
measurement housing
pressure vessel
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JP2001108784A (en
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孝一 黒沢
正之 西野
義紀 鈴木
元正 布施
治男 藤森
陽一 馬原
光男 松本
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Hitachi Ltd
Mitsubishi Power Ltd
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Babcock Hitachi KK
Hitachi Ltd
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    • 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

Description

【０００１】
【発明の属する技術分野】
本発明は、原子力発電プラントの供用期間中に原子炉圧力容器（ＲＰＶ）内の中性子計測（ＩＣＭ）ハウジングを新規製作のものと取替える取替工法に係り、特に炉水位の上げ下げ作業回数を減らし作業時間の短縮，作業者の被ばく低減に好適なＩＣＭハウジングの取替方法に関する。
【０００２】
【従来の技術】
原子力発電プラントの供用期間中にＲＰＶ内のＩＣＭハウジングを新規製作のものと取替える取替工法については、特許第2544074 号公報にて提案された技術がある。
【０００３】
特許第2544074 号公報によれば、新規ＩＣＭハウジングをＲＰＶへ取付け溶接を行う際に、ＲＰＶ底部に肉盛座を形成し、形成した肉盛座とＩＣＭハウジングを取付け溶接（以下、Ｊ溶接と略す）して取付ける手順となっている。施工にあたっては、溶接は気中で行い、溶接装置の取付け，取外し作業は水中で行う手順となっている。また、肉盛座を形成するためには、肉盛溶接した後、放電加工機を挿入して新規ＩＣＭハウジングを取付けるための穴加工と外側加工を水中で行う必要があった。
【０００４】
中性子計測（ＩＣＭ）案内管と新規ＩＣＭハウジングの接続は形状記憶合金を用いた継ぎ手に蒸気を適用して締結していた。
【０００５】
【発明が解決しようとする課題】
従来の技術を供用期間中におけるＩＣＭハウジング取替作業に適用した場合、ＩＣＭハウジングをＲＰＶに取付け溶接する肉盛座を形成するための高精度な肉盛溶接装置が必要である。更には、水中でＥＤＭ装置を挿入して肉盛座を整形する作業を行うことから、多数の装置が必要である。施工にあたっては肉盛溶接及び新規ＩＣＭハウジングのＪ溶接は気中で行い、溶接装置の取付け，取外し作業は水中で行う手順となっている。ＲＰＶに炉水を満水状態にする作業及び排水する作業はかなりの時間を要することから、ＩＣＭハウジング取替工程を長期化させる問題もある。
【０００６】
また、ＩＣＭ案内管と新規ＩＣＭハウジングの接続は、形状記憶合金を用いたカップリングに蒸気を適用して締結するために、高温でしかも多量の蒸気を必要とする問題もあった。
【０００７】
本発明は、上述した事情を考慮してなされたもので、供用期間中にＩＣＭハウジングを取替える必要が生じた場合に、短期間で効率良く取替えができる方法を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明では、先ずＲＰＶ内の機器を取外した後に、ＲＰＶ下方よりＩＣＭハウジング内に加工機を挿入し、ＩＣＭハウジング内面よりＪ溶接部及びＩＣＭ案内管を切断してＩＣＭハウジングをＲＰＶ外に搬出する。次に、新規ＩＣＭハウジングをＲＰＶ下方より搬入し、既設のＩＣＭハウジングまたはＩＣＭ案内管、及び肉盛座に溶接して取付ける。
【０００９】
以上のように本発明によれば、新たにＲＰＶ内面に肉盛座を形成することなく、また、形状記憶合金の継ぎ手を使用しないことにより短期間で効率よく行うことができる。
【００１０】
炉水位の上げ下げの作業回数が減らせることから期間短縮が期待できる。
【００１１】
炉水位の上げ下げの作業が不要となることから更なる期間短縮が期待できる。
【００１２】
狭隘なＲＰＶ底部においてＩＣＭハウジングをＪ溶接するためのＪ開先加工を容易に行うことができる。
【００１３】
狭隘なＲＰＶ底部においてＩＣＭ案内管とＩＣＭハウジングを接続した後、馬蹄形の溶接ヘッドとしたことによりＩＣＭハウジングをＲＰＶに取付け溶接を行うことができる。
【００１４】
装置をＲＰＶ底部に据付ける際、線量の高い炉心領域を短時間で通過させることができることから、装置の放射線劣化を低減することができる。また、ガイドパイプに挿入用レールを備えたことにより、ＲＰＶ上部において装置の周方向の位置決めが行えるため、
ＲＰＶ底部において装置の周方向の位置調整が不要となることから短時間で装置の据付け作業を行うことができる。
【００１５】
【発明の実施の形態】
以下、本発明の実施例を図１〜図１０で説明する。図１は、沸騰水型原子炉のＲＰＶ１及び炉内構造物を示し、ＲＰＶ１内にはドライヤ２，セパレータ３，シュラウド４等が据付けられ、シュラウド４には燃料を支持サポートするための上部格子板５，炉心支持板６等が取付けられている。
【００１６】
ＲＰＶ１の底部には、ＩＣＭハウジング７及び制御棒駆動機構（ＣＲＤ）ハウジング８がＲＰＶ１を貫通して溶接により取付けられ、ＩＣＭハウジング７の上部にはＩＣＭ案内管９が溶接により取付けられている。ＩＣＭハウジング７及びＩＣＭ案内管９には、中性子計測器を収容した図示しないＩＣＭモニタ本体がＩＣＭ案内管９の上方より挿通され、ＩＣＭモニタは原子炉の出力を監視する。図２において、１０はＲＰＶ１内面側の貫通孔周縁に高ニッケル鋼（インコネル）で形成した肉盛座、１１は肉盛座の上部に形成した開先、１２は開先に形成した高ニッケル鋼(インコネル)の溶接部である。ＩＣＭハウジング７はＲＰＶ１を貫通し、ＩＣＭハウジング７の上部がＲＰＶ１の内面側でＪ溶接されている。ＩＣＭハウジング７はステンレス鋼で形成されており、特に初期に建設された原子力発電所では炭素量の多いステンレス鋼が採用されているため、ＲＰＶとＩＣＭハウジングとの溶接部近傍のＩＣＭハウジング７、例えば溶接部１２の直上のＩＣＭハウジングには応力腐食割れが発生する恐れがある。
【００１７】
図３は、本発明の主たる部分である炉水を抜いてＲＰＶ上方より装置を設定する場合、ＲＰＶフランジ面に装置を挿入するためのガイドパイプ１３，据付け治具１４及びケーブル処理装置１５を備えた遮蔽体１６を設置してＩＣＭハウジング取替工法を実施する状態を示す。
【００１８】
ガイドパイプ１３は円筒形の分割構造としており、ＲＰＶフランジ面に据付けられた遮蔽体１６からＲＰＶ内の上部格子板５，炉心支持板６を貫通してＣＲＤハウジング上に据付けられる。ガイドパイプ１３の内面には装置据付け時の周方向を合わせるための挿入用レールが取付けられ、ガイドパイプ１３の下端は装置が繰り出せるように半割形状となっている。
【００１９】
図４は、本実施形態に係わるＩＣＭハウジングの取替方法を示すフローチャートである。先ず、ステップＳ１においてＲＰＶ１内に取付けられているドライヤ２，セパレータ３等の炉内機器を取外し、ＲＰＶ１内より搬出して所定の場所に保管し、ＲＰＶ上方よりＲＰＶ底部へのアクセスが可能な状態にする。
【００２０】
次に、ステップＳ２において炉水位をＲＰＶフランジ面直下まで下げ、ガイドパイプ１３，据付け治具１４，ケーブル処理装置１５及び遮蔽体１６を設置した後、ステップＳ３においてＲＰＶ１内部の炉水を全てドレンする。これにより、従来工法では水中で実施していた装置の取付け，取外し作業を気中で行うことが可能となることから、短時間で効率良く行うことができる。
【００２１】
続いて、ステップＳ４においてＲＰＶ１下方よりＩＣＭハウジング７内に加工機を挿入し、ＩＣＭ案内管９を内面より切断する。図５はＩＣＭ案内管を切断した状態を示す。
【００２２】
続いて、ステップＳ５においてＲＰＶ１下方よりＩＣＭハウジング７内に加工機を挿入し、Ｊ溶接部１２の上端部のＩＣＭハウジングを内面より切断する。この時、切断した上方のＩＣＭハウジング７ａは周囲のＣＲＤハウジングにＩＣＭハウジング保持具を介して取付けられ、落下しないように保持される（図示せず）。図６は、ＩＣＭハウジングを切断した状態を示す。
【００２３】
次に、下方のＩＣＭハウジング７ｂを引き抜きして取外すために、Ｊ溶接部１２の下端部のＩＣＭハウジングを内面から切込み１７を加工する。図７は、ＩＣＭハウジングに切込みを加工した状態を示す。
【００２４】
なお、前述の作業ステップにおいて、先にステップＳ５のＩＣＭハウジング７を切断した後、ステップＳ４のＩＣＭ案内管９を切断することも可能である。
【００２５】
ステップＳ６では、切断した上方のＩＣＭハウジング７ａ及び下方のＩＣＭハウジング７ｂをＲＰＶ下方より強制引き抜きして取外し、ＲＰＶ外へ搬出する。図８はＩＣＭハウジングをＲＰＶ外に搬出した状態を示す。
【００２６】
続いて、ステップＳ７においてＲＰＶ１下方より加工機を挿入してＲＰＶ内のＩＣＭ案内管９下端部の開先１８を加工する。同様に、ステップＳ８においてＲＰＶ１下方より加工機を挿入してＲＰＶ内の肉盛座１０のＪ開先１９を加工する。図９は、ＩＣＭ案内管９に開先１８の加工、及びＲＰＶ１内面の肉盛座１０にＪ開先１９を加工した状態を示す。
【００２７】
なお、前述の作業ステップにおいて、先にステップＳ８の肉盛座１０の開先１９を加工した後、ステップＳ７のＩＣＭ案内管９の開先１８を加工することも可能である。
【００２８】
ステップＳ９では、ステップＳ８で加工した肉盛座１０のＪ開先１９面の浸透探傷検査を行う。ステップＳ１０においてＲＰＶ１下方より開先加工した新規ＩＣＭハウジング２０を挿入してＩＣＭ案内管９と開先合わせを行い、新規ICMハウジング２０下方より内面溶接機を挿入して溶接２１する。図１０にＩＣＭ案内管と新規ＩＣＭハウジングを溶接した状態を示す。
【００２９】
次に、ＲＰＶ１上方から、ＲＰＶフランジ面に装置を挿入するためのガイドパイプ１３，据付け治具１４及びケーブル処理装置１５を備えた遮蔽体１６を使用してＪ溶接機をＲＰＶ１内に挿入し、新規ＩＣＭハウジング２０をＲＰＶ１内の肉盛座１０にＪ溶接２２する。図１１は、新規ＩＣＭハウジングをＲＰＶに溶接した状態を示す。
【００３０】
図１２は、ＲＰＶ下方よりＲＰＶ内に挿入してＲＰＶ１内の肉盛座１０のＪ開先１９を加工する加工ヘッドの構成を示す図である。図１２において、カッタ２３は回転軸２４を介してカサ歯車２５と連結されている。軸受２６は軸３３を介してカサ歯車２７，カサ歯車３２と連結されている。駆動軸２９にはカサ歯車２８，駆動軸３０にはカサ歯車３１が個々に取付けられている。
【００３１】
駆動軸２９，駆動軸３０をそれぞれ同速度で別（反対）方向に回転動作３６，３７させると、カサ歯車２７とカサ歯車３２も別方向に回転することになり、カサ歯車２５に回転動作を与えることができ、回転軸２４を介してカッタ２３が回転動作３４を行うことができる。
【００３２】
一方、駆動軸２９だけに回転動作３６を与え駆動軸３０を固定した場合、カサ歯車３２が回転しないためカサ歯車２５も回転せずに固定状態となる。カサ歯車２７だけが回転するため、軸３３を中心としてカッタ２３，回転軸２４，軸受２６が揺動動作３５できる。また、カッタ２３が回転中においても、駆動軸２９と駆動軸３０の回転数を変えることにより揺動動作３５を行うことができる。
【００３３】
図１３は、ＲＰＶ上方より、ガイドパイプを使用してＲＰＶ内に挿入し、新規ＩＣＭハウジングをＲＰＶ内の肉盛座にＪ溶接する溶接ヘッドの構成を示す図である。図１３において、上部馬蹄形外筒４０はアーム３９により溶接ヘッド据付治具３８と連結されており、アーム３９をスイング動作４７させることにより上部馬蹄形外筒４０の中心をＩＣＭ案内管９の中心位置まで移動できる。上部馬蹄形外筒４０にはクランプ機構部４１，４２が備えられており、上部馬蹄形外筒４０をＩＣＭ案内管９にクランプすることができる。
【００３４】
下部馬蹄形外筒４４は回転駆動部４３により上部馬蹄形外筒４０と連結されており、ＩＣＭ案内管９を中心に回転動作が行える。下部馬蹄形外筒４４には溶接トーチ上下駆動部４５が備えられており、溶接トーチ４６の上下動作を行うことができる。また、下部馬蹄形外筒４４を防水機能を有する形状にすれば、水中で装置の据付けを行うこともできる。
【００３５】
【発明の効果】
本発明によれば、原子力発電プラントの供用期間中にＲＰＶ内のＩＣＭハウジングを新規製作のものと取替える場合、特に炉水位の上げ下げ作業回数を減らし作業時間の短縮，作業者の被ばく低減ができる。
【００３６】
更に、本発明の加工機，溶接機によれば狭隘なＲＰＶ底部においても、Ｊ開先加工及び溶接ができるので、効率よく短時間で作業を行うことができる。
【図面の簡単な説明】
【図１】沸騰水型原子炉の原子炉圧力容器及び炉内構造物を示す図。
【図２】ＩＣＭハウジング取付け部を示す図。
【図３】炉水を抜いてＲＰＶ上方より装置を設定する状態を示す図。
【図４】本発明の実施形態によるＩＣＭハウジング取替方法のフローチャート。
【図５】ＩＣＭ案内管を切断した状態を示す図。
【図６】ＩＣＭハウジングを切断した状態を示す図。
【図７】ＩＣＭハウジングに切込みを加工した状態を示す図。
【図８】ＩＣＭハウジングをＲＰＶ外に搬出した状態を示す図。
【図９】ＩＣＭ案内管の開先及びＪ開先を加工した状態を示す図。
【図１０】ＩＣＭ案内管と新規ＩＣＭハウジングを溶接した状態を示す図。
【図１１】新規ＩＣＭハウジングをＲＰＶにＪ溶接した状態を示す図。
【図１２】Ｊ開先を加工する加工ヘッドの構成を示す図。
【図１３】ＩＣＭハウジングを溶接するＪ溶接ヘッドの構成を示す図。
【符号の説明】
１…原子炉圧力容器（ＲＰＶ）、２…ドライヤ、３…セパレータ、４…シュラウド、５…上部格子板、６…炉心支持板、７…既設ＩＣＭハウジング、７ａ…切断した上方の既設ＩＣＭハウジング、７ｂ…切断した下方の既設ＩＣＭハウジング、８…ＣＲＤハウジング、９…ＩＣＭ案内管、１１…開先、１２…Ｊ溶接、１３…ガイドパイプ、１４…据付け治具、１５…ケーブル処理装置、１６…遮蔽体、１７…切込み、１８…ＩＣＭ案内管の開先、１９…Ｊ開先、２０…新規ICMハウジング、２１…溶接部、２２…Ｊ溶接部、２３…カッタ、２４…回転軸、２５…カサ歯車、２６…軸受、２７，２８，３１，３２…カサ歯車、２９，３０…駆動軸、３３…軸、３４，３６，３７…回転動作、３５…揺動動作、３８…溶接ヘッド据付治具、３９…アーム、４０…上部馬蹄形外筒、４１，４２…クランプ、４３…回転駆動部、４４…下部馬蹄形外筒、４５…溶接トーチ上下駆動部、４６…溶接トーチ、４７…スイング動作。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a replacement method for replacing a neutron measurement (ICM) housing in a reactor pressure vessel (RPV) with a newly manufactured one during the operation period of a nuclear power plant, and in particular, reducing the number of times of raising and lowering the reactor water level. The present invention relates to an ICM housing replacement method suitable for shortening time and reducing exposure of workers.
[0002]
[Prior art]
Regarding the replacement method for replacing the ICM housing in the RPV with a newly manufactured one during the operation period of the nuclear power plant, there is a technique proposed in Japanese Patent No. 2544704.
[0003]
According to Japanese Patent No. 2544704, when a new ICM housing is attached and welded to an RPV, a build-up seat is formed on the bottom of the RPV, and the formed build-up seat and the ICM housing are attached and welded (hereinafter abbreviated as J-weld). ) To install. At the time of construction, welding is performed in the air, and the welding apparatus is attached and removed in water. Further, in order to form the build-up seat, it was necessary to perform hole machining and external machining in water for inserting the electric discharge machine and attaching the new ICM housing after overlay welding.
[0004]
The connection between the neutron measurement (ICM) guide tube and the new ICM housing was concluded by applying steam to a joint using a shape memory alloy.
[0005]
[Problems to be solved by the invention]
When the conventional technique is applied to the ICM housing replacement operation during the service period, a high-accuracy overlay welding apparatus for forming the overlay seat for attaching and welding the ICM housing to the RPV is necessary. Furthermore, since the EDM apparatus is inserted in water and the work of shaping the build-up seat is performed, a large number of apparatuses are necessary. In construction, build-up welding and J welding of the new ICM housing are performed in the air, and the welding apparatus is attached and removed in water. Since it takes a considerable amount of time to fill the reactor water with the RPV and drain the reactor water, there is also a problem of prolonging the ICM housing replacement process.
[0006]
In addition, the connection between the ICM guide tube and the new ICM housing has a problem of requiring a large amount of steam at a high temperature because the steam is applied to the coupling using the shape memory alloy.
[0007]
The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a method that enables efficient replacement in a short period of time when it is necessary to replace an ICM housing during a service period.
[0008]
[Means for Solving the Problems]
In the present invention, first, after removing the equipment in the RPV, the processing machine is inserted into the ICM housing from below the RPV, the J weld and the ICM guide tube are cut from the inner surface of the ICM housing, and the ICM housing is carried out of the RPV. . Next, a new ICM housing is carried in from below the RPV, and is welded and attached to an existing ICM housing or ICM guide tube and build-up seat.
[0009]
As described above, according to the present invention, it can be efficiently performed in a short period of time without newly forming a built-up seat on the inner surface of the RPV and without using a joint of a shape memory alloy.
[0010]
The period can be expected to be shortened because the number of times of raising and lowering the reactor water level can be reduced.
[0011]
Since the work of raising and lowering the reactor water level is unnecessary, further shortening of the period can be expected.
[0012]
The ICM housing J beveling for J welding can be easily performed in the narrow隘of RPV bottom.
[0013]
After connecting the ICM guide tube and ICM housing in the narrow隘of RPV bottom, it is possible to perform the mounting welding ICM housing RPV by which the horseshoe-shaped welding head.
[0014]
When installing the equipment in the RPV bottom, since it is possible to pass in a short time with high core region doses, it can reduce the radiation deterioration of the device. In addition, since the guide pipe is provided with an insertion rail, the apparatus can be positioned in the circumferential direction at the top of the RPV.
Since it is not necessary to adjust the position of the apparatus in the circumferential direction at the bottom of the RPV, the apparatus can be installed in a short time.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows an RPV 1 and a reactor internal structure of a boiling water reactor, and a dryer 2, a separator 3, a shroud 4 and the like are installed in the RPV 1, and an upper grid plate for supporting and supporting fuel in the shroud 4 5, a core support plate 6 and the like are attached.
[0016]
An ICM housing 7 and a control rod drive mechanism (CRD) housing 8 are attached to the bottom of the RPV 1 by welding through the RPV 1, and an ICM guide tube 9 is attached to the top of the ICM housing 7 by welding. An ICM monitor body (not shown) containing a neutron measuring instrument is inserted into the ICM housing 7 and the ICM guide tube 9 from above the ICM guide tube 9, and the ICM monitor monitors the output of the reactor. In FIG. 2, 10 is a built-up seat formed of high nickel steel (Inconel) on the periphery of the through hole on the inner surface side of RPV 1, 11 is a groove formed on the top of the built-up seat, and 12 is a high nickel steel formed on the groove. It is a welded part of (Inconel). The ICM housing 7 penetrates the RPV 1 and the upper part of the ICM housing 7 is J-welded on the inner surface side of the RPV 1. The ICM housing 7 is formed of stainless steel, and particularly in nuclear power plants constructed in the early stage, stainless steel having a large amount of carbon is adopted. Therefore, the ICM housing 7 in the vicinity of the welded portion between the RPV and the ICM housing, for example, There is a risk of stress corrosion cracking occurring in the ICM housing directly above the welded portion 12.
[0017]
FIG. 3 includes a guide pipe 13, an installation jig 14, and a cable processing device 15 for inserting the device into the RPV flange surface in the case where the device is set from above the RPV by removing the reactor water which is the main part of the present invention. The state which installed the shield 16 which implemented the ICM housing replacement construction method is shown.
[0018]
The guide pipe 13 has a cylindrical divided structure, and is installed on the CRD housing from the shield 16 installed on the RPV flange surface through the upper lattice plate 5 and the core support plate 6 in the RPV. An insertion rail for aligning the circumferential direction when the apparatus is installed is attached to the inner surface of the guide pipe 13, and the lower end of the guide pipe 13 is halved so that the apparatus can be extended.
[0019]
FIG. 4 is a flowchart showing an ICM housing replacement method according to this embodiment. First, in step S1, the in-furnace equipment such as the dryer 2 and separator 3 attached in the RPV 1 is removed, removed from the RPV 1, stored in a predetermined location, and accessible to the RPV bottom from above the RPV. To.
[0020]
Next, in step S2, the reactor water level is lowered to just below the RPV flange surface, and after the guide pipe 13, the installation jig 14, the cable processing device 15 and the shield 16 are installed, all the reactor water inside the RPV 1 is drained in step S3. . As a result, it is possible to perform attachment and detachment work of the apparatus that has been performed underwater in the conventional method in the air, and therefore can be performed efficiently in a short time.
[0021]
Subsequently, in step S4, a processing machine is inserted into the ICM housing 7 from below the RPV 1, and the ICM guide tube 9 is cut from the inner surface. FIG. 5 shows a state where the ICM guide tube is cut.
[0022]
Subsequently, in step S5, a processing machine is inserted into the ICM housing 7 from below the RPV 1, and the ICM housing at the upper end of the J weld 12 is cut from the inner surface. At this time, the cut upper ICM housing 7a is attached to the surrounding CRD housing via the ICM housing holder and is held so as not to fall (not shown). FIG. 6 shows a state where the ICM housing is cut.
[0023]
Next, in order to pull out and remove the lower ICM housing 7b, the ICM housing at the lower end of the J weld 12 is cut from the inner surface. FIG. 7 shows a state in which a cut is processed in the ICM housing.
[0024]
In the above-described operation step, it is also possible to cut the ICM guide tube 9 in step S4 after cutting the ICM housing 7 in step S5 first.
[0025]
In step S6, the upper ICM housing 7a and the lower ICM housing 7b that have been cut are forcibly pulled out from below the RPV, removed, and carried out of the RPV. FIG. 8 shows a state where the ICM housing is carried out of the RPV.
[0026]
Subsequently, in step S7, a processing machine is inserted from below the RPV 1 to process the groove 18 at the lower end of the ICM guide tube 9 in the RPV. Similarly, in step S8, a processing machine is inserted from below the RPV 1 to process the J groove 19 of the build-up seat 10 in the RPV. FIG. 9 shows a state in which the groove 18 is processed in the ICM guide tube 9 and the J groove 19 is processed in the build-up seat 10 on the inner surface of the RPV 1.
[0027]
In the above-described operation step, it is also possible to process the groove 18 of the ICM guide tube 9 in step S7 after processing the groove 19 of the built-up seat 10 in step S8.
[0028]
In step S9, the penetrant inspection of the J groove 19 surface of the built-up seat 10 processed in step S8 is performed. In step S10, a new ICM housing 20 that has been grooved is inserted from below the RPV 1 to be aligned with the ICM guide tube 9, and an inner surface welder is inserted from below the new ICM housing 20 to perform welding 21. FIG. 10 shows a state where the ICM guide tube and the new ICM housing are welded.
[0029]
Next, from above the RPV 1, the J welder is inserted into the RPV 1 using the shield 16 having the guide pipe 13 for inserting the device on the RPV flange surface, the installation jig 14 and the cable processing device 15. The new ICM housing 20 is J-welded 22 to the build-up seat 10 in the RPV 1. FIG. 11 shows the new ICM housing welded to the RPV.
[0030]
FIG. 12 is a diagram showing a configuration of a machining head that is inserted into the RPV from below the RPV to process the J groove 19 of the build-up seat 10 in the RPV 1. In FIG. 12, the cutter 23 is connected to a bevel gear 25 via a rotating shaft 24. The bearing 26 is connected to a bevel gear 27 and a bevel gear 32 via a shaft 33. A bevel gear 28 is attached to the drive shaft 29, and a bevel gear 31 is attached to the drive shaft 30.
[0031]
When the drive shaft 29 and the drive shaft 30 are rotated in different (opposite) directions at the same speed, the bevel gear 27 and the bevel gear 32 are also rotated in different directions, and the bevel gear 25 is rotated. The cutter 23 can perform the rotation operation 34 via the rotation shaft 24.
[0032]
On the other hand, when the rotation operation 36 is applied only to the drive shaft 29 and the drive shaft 30 is fixed, the bevel gear 32 does not rotate, and the bevel gear 25 does not rotate and is fixed. Since only the bevel gear 27 rotates, the cutter 23, the rotating shaft 24, and the bearing 26 can swing about the shaft 33. Even when the cutter 23 is rotating, the swinging operation 35 can be performed by changing the rotational speeds of the drive shaft 29 and the drive shaft 30.
[0033]
FIG. 13 is a view showing a configuration of a welding head that is inserted into the RPV from above the RPV using a guide pipe and J-welds the new ICM housing to the built-up seat in the RPV. In FIG. 13, the upper horseshoe-shaped outer cylinder 40 is connected to the welding head installation jig 38 by an arm 39, and the center of the upper horseshoe-shaped outer cylinder 40 is moved to the center position of the ICM guide tube 9 by swinging the arm 39. I can move. The upper horseshoe-shaped outer cylinder 40 is provided with clamping mechanisms 41 and 42, and the upper horseshoe-shaped outer cylinder 40 can be clamped to the ICM guide tube 9.
[0034]
The lower horseshoe-shaped outer cylinder 44 is connected to the upper horseshoe-shaped outer cylinder 40 by a rotation driving unit 43 and can rotate around the ICM guide tube 9. The lower horseshoe-shaped outer cylinder 44 is provided with a welding torch vertical drive unit 45, and the welding torch 46 can be moved up and down. Further, if the lower horseshoe-shaped outer cylinder 44 has a waterproof function, the apparatus can be installed in water.
[0035]
【The invention's effect】
According to the present invention, when the ICM housing in the RPV is replaced with a newly manufactured one during the operation period of the nuclear power plant, the number of times of raising and lowering the reactor water level can be reduced, and the working time can be shortened and the exposure of workers can be reduced.
[0036]
Furthermore, according to the processing machine and the welding machine of the present invention, even in a narrow RPV bottom, J groove processing and welding can be performed, so that work can be performed efficiently and in a short time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a reactor pressure vessel and a reactor internal structure of a boiling water reactor.
FIG. 2 is a view showing an ICM housing mounting portion.
FIG. 3 is a diagram showing a state in which the reactor water is drained and the apparatus is set from above the RPV.
FIG. 4 is a flowchart of an ICM housing replacement method according to an embodiment of the present invention.
FIG. 5 is a diagram showing a state where an ICM guide tube is cut.
FIG. 6 is a diagram showing a state where an ICM housing is cut.
FIG. 7 is a view showing a state in which a cut is processed in the ICM housing.
FIG. 8 is a diagram showing a state in which the ICM housing is carried out of the RPV.
FIG. 9 is a view showing a state in which the groove and the J groove of the ICM guide tube are processed.
FIG. 10 is a view showing a state where an ICM guide tube and a new ICM housing are welded.
FIG. 11 is a view showing a state in which a new ICM housing is J-welded to RPV.
FIG. 12 is a diagram showing a configuration of a machining head for machining a J groove.
FIG. 13 is a diagram showing a configuration of a J welding head for welding an ICM housing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel (RPV), 2 ... Dryer, 3 ... Separator, 4 ... Shroud, 5 ... Upper lattice board, 6 ... Core support plate, 7 ... Existing ICM housing, 7a ... The existing ICM housing of the cut upper part, 7b: Cut existing ICM housing, 8: CRD housing, 9: ICM guide tube, 11: groove, 12 ... J weld, 13 ... guide pipe, 14 ... installation jig, 15 ... cable processing device, 16 ... Shielding body, 17 ... notch, 18 ... ICM guide pipe groove, 19 ... J groove, 20 ... new ICM housing, 21 ... welded part, 22 ... J welded part, 23 ... cutter, 24 ... rotating shaft, 25 ... Bevel gear, 26 ... bearing, 27, 28, 31, 32 ... bevel gear, 29, 30 ... drive shaft, 33 ... shaft, 34, 36, 37 ... rotational motion, 35 ... swing motion, 38 ... welding head installation cure Tool, 39 ... A Arm, 40 ... upper horseshoe outer cylinder 41 ... clamp, 43 ... rotational driving portion, 44 ... lower horseshoe outer cylinder 45 ... welding torch vertical drive unit, 46 ... welding torch, 47 ... swing motion.

Claims (6)

原子炉圧力容器の内面に形成した肉盛座を貫通し且つ前記肉盛座に取付け溶接され、その上部が中性子計測案内管に溶接されている円筒状の中性子計測ハウジングの取替方法において、
前記原子炉圧力容器の下方から前記中性子計測ハウジング内に加工機を挿入し、前記中性子計測ハウジングの内面から、前記取付け溶接部および前記取付け溶接部よりも上部の前記中性子計測ハウジングまたは前記中性子計測案内管を切断し、前記中性子計測ハウジングを前記原子炉圧力容器の外に搬出し、
その後、新規の中性子計測ハウジングを前記原子炉圧力容器の下方から搬入し、前記原子炉圧力容器の下方から前記新規の中性子計測ハウジング内に溶接機を挿入して、前記新規の中性子計測ハウジングの内面から前記新規の中性子継続ハウジングと既設の中性子計測ハウジングまたは中性子計測案内管とを溶接し、さらに前記原子炉圧力容器の上方から前記原子炉圧力容器内に溶接機を挿入して、前記新規の中性子計測ハウジングの外面から前記新規の中性子ハウジングを前記肉盛座に溶接により取付けることを特徴とする中性子計測ハウジングの取替方法。In the replacement method of the cylindrical neutron measurement housing that penetrates the build-up seat formed on the inner surface of the reactor pressure vessel and is welded to the build-up seat and welded to the neutron measurement guide tube,
A processing machine is inserted into the neutron measurement housing from below the reactor pressure vessel, and the neutron measurement housing or the neutron measurement guide above the attachment weld and the attachment weld from the inner surface of the neutron measurement housing. Cutting the tube, unloading the neutron measurement housing out of the reactor pressure vessel,
Thereafter, a new neutron measurement housing is carried from below the reactor pressure vessel, a welding machine is inserted into the new neutron measurement housing from below the reactor pressure vessel, and an inner surface of the new neutron measurement housing is inserted. The new neutron continuation housing is welded to the existing neutron measurement housing or neutron measurement guide tube , and a welder is inserted into the reactor pressure vessel from above the reactor pressure vessel, and the new neutron A method for replacing a neutron measurement housing, characterized in that the new neutron housing is attached to the build-up seat by welding from the outer surface of the measurement housing . 請求項１に記載の中性子計測ハウジングの取替方法において、前記取付け溶接部よりも下側の中性子計測ハウジングを切断して前記原子炉圧力容器の下方に引き抜き、その後、前記取付け溶接部よりも上側の中性子計測ハウジングまたは中性子計測案内管を切断し、該切断部よりも上側の前記中性子計測ハウジングまたは前記中性子計測案内管と治具により固定し、その後に前記取付け溶接部を切断することを特徴とする中性子計測ハウジングの取替方法。  2. The method of replacing a neutron measurement housing according to claim 1, wherein the neutron measurement housing below the attachment weld is cut and pulled out below the reactor pressure vessel, and then above the attachment weld. Cutting the neutron measurement housing or neutron measurement guide tube, fixing the neutron measurement housing or neutron measurement guide tube and the neutron measurement guide tube above the cut portion with a jig, and then cutting the attachment weld. To replace the neutron measurement housing. 請求項１に記載の中性子計測ハウジングの取替方法において、前記取付け溶接部よりも上側の中性子計測ハウジングまたは中性子計測案内管を切断し、該切断部よりも上側の中性子計測ハウジングまたは中性子計測案内管と治具により固定し、その後、前記取付け溶接部よりも下側の中性子計測ハウジングを切断して前記原子炉圧力容器の下方に引き抜き、その後に前記取付け溶接部を切断することを特徴とする中性子計測ハウジングの取替方法。  2. The method of replacing a neutron measurement housing according to claim 1, wherein the neutron measurement housing or neutron measurement guide tube above the attachment weld is cut, and the neutron measurement housing or neutron measurement guide tube above the cut portion. The neutron is characterized in that the neutron measurement housing below the attachment weld is cut and pulled below the reactor pressure vessel, and then the attachment weld is cut. How to replace the measurement housing. 請求項１乃至３の何れかに記載の中性子計測ハウジングの取替方法において、既設の中性子計測ハウジングおよび中性子計測案内管の切断は、炉水を抜いて前記原子炉圧力容器の下方から実施することを特徴とする中性子計測ハウジングの取替方法。In replacement method neutron measurement housing according to any one of claims 1 to 3, the cutting of the neutron monitoring housing and neutron monitoring guide tube of the existing shall be performed from below the reactor pressure vessel by far the reactor water Replacement method of neutron measurement housing characterized by 請求項１乃至３の何れかに記載の中性子計測ハウジングの取替方法において、既設の中性子計測ハウジングおよび中性子計測案内管の切断、並びに新規の中性子計測ハウジングと既設の中性子計測ハウジングまたは中性子計測案内管との溶接は、炉水を抜いて前記原子炉圧力容器の下方から実施することを特徴とする中性子計測ハウジングの取替方法。In replacement method neutron measurement housing according to any one of claims 1 to 3, the cutting of the existing neutron measurement housing and neutron monitoring guide tube, and novel neutron measurement housing and the existing neutron monitoring housing or neutron measurement guide tube The method of replacing the neutron measurement housing is characterized in that the welding is performed from below the reactor pressure vessel with the reactor water removed. 請求項１乃至５の何れかに記載の中性子計測ハウジングの取替方法において、前記原子炉圧力容器内に炉水が存在する状態で、原子炉圧力容器フランジ面に、前記新規の中性子ハウジングを前記肉盛座に溶接する前記溶接機を挿入するためのガイドパイプ及び据付治具を備えた遮蔽体を設置し、6. The method of replacing a neutron measurement housing according to claim 1, wherein the new neutron housing is placed on a reactor pressure vessel flange surface in a state where reactor water exists in the reactor pressure vessel. Installed a shield with a guide pipe and an installation jig for inserting the welding machine for welding to the build-up seat,
その後、前記原子炉圧力容器内から炉水を抜いた後に、前記新規の中性子ハウジングを前記肉盛座に溶接することを特徴とする中性子計測ハウジングの取替方法。Thereafter, after draining reactor water from the reactor pressure vessel, the new neutron housing is welded to the build-up seat.
JP28768699A 1999-10-08 1999-10-08 Replacement method of neutron measurement housing and apparatus used therefor Expired - Fee Related JP3774600B2 (en)

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