JP2005030773A

JP2005030773A - Equipment and method for inspecting the inside of reactor

Info

Publication number: JP2005030773A
Application number: JP2003192774A
Authority: JP
Inventors: Mitsuaki Shimamura; 光明島村; Tomoyuki Ito; 智之伊藤; Motohiko Kimura; 元比古木村; Yasuhiro Yuguchi; 康弘湯口
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2003-07-07
Filing date: 2003-07-07
Publication date: 2005-02-03
Anticipated expiration: 2023-07-07
Also published as: JP3819380B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and equipment for inspecting the inside of a reactor which efficiently inspects in-reactor structures including shrouds placed in a reactor pressure vessel with high workability. <P>SOLUTION: The equipment is equipped with an underwater traveling vehicle 1 which moves in a three-dimensional directions in a reactor 41 with a pool of water, an inspection sensor 2 mounted on the under water traveling vehicle 1 via an inspection sensor holding section 3, a positioning means 30 which is placed in the reactor 41 and is a referencee of the position of the vehicle 1 to the in-reactor structures, a control manipulation component 5 which is placed outside a reactor 11 to control the actions of the vehicle 1 and an inspection sensor output signal processing component 6 into which output signals from an inspection sensor 9 are inputted to process them. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、原子炉圧力容器内に設けられたシュラウド等の炉内構造物の検査を行う原子炉内検査装置および方法に関する。
【０００２】
【従来の技術】
沸騰水型原子炉においては原子炉圧力容器内に溶接構造物であるシュラウドが設けられており、また、上部格子板と炉心支持板の間の炉心部や、炉心支持板より下の炉下部にも溶接部が存在する。
【０００３】
従来、上述のような炉心部ないし炉下部に存在する溶接部の点検、検査を行うためには、各種の点検センサや機器を長尺のポールの先端に取付け、人が炉上部から吊降ろし、上部格子板、炉心支持板を通過させて操りながら作業を行っている。また、上部格子板の格子や炉心支持板の穴を通過可能な上下に長い筐体内に、各種の点検センサの位置決めや、保持を行うマニピュレータや送り込み機構を設け、これを炉心支持板上や炉下部のＣＲＤハウジング上に設置して各種の作業を行っている。さらに、近年原子炉内の点検、検査を行う自動化装置も種々開発されている（下記特許文献１，２，３，４参照）。
【０００４】
【特許文献１】
特開平８−２０１５６８号公報
【特許文献２】
特開平１１−１４７８４号公報
【特許文献３】
特開平１１−２１１８７８号公報
【特許文献４】
特開２００３−４０１９４号公報
【０００５】
【発明が解決しようとする課題】
原子炉内検査作業を人手により行う場合は、検査範囲が点検センサを通過させた上部格子板の格子や炉心支持板の穴の近傍に限られてしまうので、シュラウドに沿って検査するには何度も上部格子板の上まで点検センサを引上げて再度吊降ろさなければならない。さらに水中下２５ｍもの位置で長尺のポールを操らなければならないので非常に作業性が悪く、多くの時間と労力を要する。また長尺の装置を炉心部や炉底部に設置して作業を行う場合でも、一つの設置位置から検査可能な範囲は限られており、設置位置を変更するには大型の装置を上部格子板の上まで吊上げてから次の設置位置に移動しなければならないので、これも時間と労力を要する作業となっていた。
【０００６】
本発明はかかる従来の事情に対処してなされたものであり、原子炉圧力容器内に設けられたシュラウド等の炉内構造物の検査を作業性よく効率的に行うことのできる原子炉内検査装置および方法を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、請求項１の発明の原子炉内検査装置は、水を貯留した原子炉内を三次元方向に移動する水中移動ビークルと、前記水中移動ビークルに点検センサ保持部を介して取付けられた点検センサと、前記原子炉内に設けられ炉内構造物に対する前記水中移動ビークルの位置の基準となる位置決め手段と、前記原子炉外に設けられ前記水中移動ビークルの動作を制御する制御操作部と、前記点検センサの出力信号を入力されて処理する点検センサ出力信号処理部とを備えている構成とする。
【０００８】
請求項２の発明は、前記水中移動ビークルは、前記原子炉の上下方向に沿う推力を生じる上下スラスタと、前記原子炉の水平方向に沿う推力を生じる水平スラスタと、浮力を生じるフロートと、傾斜を検知する傾斜センサと、炉内構造物表面を走行する車輪と、前記走行の距離を計測する距離計とを備えている構成とする。
【０００９】
請求項３の発明は、前記点検センサは、目視検査用カメラまたは体積検査用超音波センサまたは渦流探傷用センサである構成とする。
請求項４の発明は、前記点検センサ保持部は、前記点検センサを前記水中移動ビークルの炉内構造物への吸着面に対向して近接離隔可動に支持し、前記吸着面までの距離を保つローラまたは自在車輪と、前記吸着面への押付け手段とを備え、前記点検センサを前記炉内構造物に対して所定の距離に保つ構成とする。
【００１０】
請求項５の発明は、前記吸着面への押付け手段はスラスタまたはスプリングである構成とする。
請求項６の発明は、前記位置決め手段は、原子炉内の特定の炉内構造物に設置される治具であり、前記治具に前記水中移動ビークルを機械的に接触させて炉内構造物に対する前記水中移動ビークルの位置を設定する構成とする。
【００１１】
請求項７の発明は、前記位置決め手段は、原子炉内の特定の炉内構造物に設置された治具上に設けられた距離センサを備え、前記治具に前記水中移動ビークルを接近させ、前記距離センサで前記水中移動ビークルまたは前記点検センサまでの相対距離を測定することによって炉内構造物に対する前記水中移動ビークルの位置設定を行う構成とする。
【００１２】
請求項８の発明は、前記位置決め手段は、原子炉内の特定の炉内構造物に設置された水中カメラを備え、前記特定の炉内構造物と前記水中移動ビークルまたは前記点検センサの相対位置を前記水中カメラで撮影し、その画像から所定の位置に前記水中移動ビークルが位置していることを判定して前記水中移動ビークルの位置設定を行う構成とする。
【００１３】
請求項９の発明は、前記位置決め手段は、原子炉内の特定の炉内構造物に設置され撮影部位が既知である水中カメラを備え、前記水中カメラの画像内の基準位置に前記水中移動ビークルまたは前記点検センサ上の標的が撮像されていることを確認し、所定の位置に前記水中移動ビークルが位置していることを判定して前記水中移動ビークルの位置設定を行う構成とする。
【００１４】
請求項１０の発明は、前記位置決め手段は、原子炉内の特定の炉内構造物に設置されたレーザーマーカと水中カメラを備え、炉内構造物に対するレーザーの照射位置をあらかじめ設定しておき、前記水中移動ビークルまたは前記点検センサ上の標的に前記レーザーが照射されていることを前記水中カメラで確認し、所定の位置に前記水中移動ビークルが位置していることを判定して前記水中移動ビークルの位置設定を行う構成とする。
【００１５】
請求項１１の発明は原子炉内検査方法であり、請求項２に記載の原子炉内検査装置において、前記制御操作部を操作して前記水中移動ビークルを前記水平スラスタにより炉内構造物に吸着させ前記車輪により前記炉内構造物上を移動させて、前記炉内構造物の検査を行う構成とする。
【００１６】
【発明の実施の形態】
以下に本発明の第１の実施の形態の原子炉内検査装置を図１〜図６を参照して説明する。図１は、本実施の形態の原子炉内検査装置によって沸騰水型原子炉内の炉内構造物であるシュラウド４２の中間部胴や下部胴内面を検査する場合を示した概念図である。
【００１７】
図１に示すように、点検センサ２を搭載した水中移動ビークル１にはケーブル４が接続されており、このケーブル４は、オペレーションフロア４８上や燃料交換機上などに設置された制御操作部５と点検センサ出力処理部６に接続されている。また、炉下部のＣＲＤ（制御棒駆動機構）ハウジング４７上にはシュラウド下部胴４９上での水中移動ビークル１の圧力容器円周方向の基準位置を定める位置決め治具３０が設置されている。さらに制御操作部５と点検センサ出力処理部６は検査位置データなどの情報授受のために相互に接続されている。
【００１８】
炉下部での検査を行う場合、点検センサ２を搭載した水中移動ビークル１は原子炉圧力容器４１の上方から炉内へ投入され、遊泳しながら潜行し上部格子板４３および炉心支持板４４を通過して炉下部へ到達する。次に位置決め治具３０により下部胴上の検査開始位置を定め、水中移動ビークル１により点検センサ２を検査箇所へ搬送して検査を開始する。
【００１９】
図２に水中移動ビークル１の構成を示す。図２に示すように、一対の上下スラスタ７が水中移動ビークル１上部に左右に同じ角度だけ傾けて配置され、中央部には一対の水平スラスタ８が配置されている。またシュラウド４２上を走行移動するためにボールキャスタ１２と、ボールキャスタ１２の反対側に二つの走行車輪９および二つの距離計測ローラ１０が配置されている。また中央下部には傾斜センサ１３が設けられている。点検センサ２はフェーズドアレイ超音波探触子であり、点検センサ保持部３により水中移動ビークル１の下部に取付けられている。点検センサ２は取付けプレート２１を介して２本のアーム２０により吊り下げられている。
【００２０】
水中移動ビークル１は、一対の上下スラスタ７の各々の回転羽根の回転方向を操作して水流の方向を組み合わせることで潜行、浮上および左右遊泳を行う。また一対の水平スラスタ８により前進、後進および垂直軸周りの旋回遊泳を行う。水中移動ビークル１の上側にはフロート１４が配置されており水中での自重と浮力がバランスするように調整することで、上部格子板４３や炉心支持板４４を通過した後に真横に遊泳してシュラウド４２内面へ向かうことができる。また水中において重心より浮力の中心が上になるように構成されているので、停止時には常に点検センサ２が下になるように保持されると共に水平スラスタ８による遊泳時の姿勢を安定させることができる。
【００２１】
水中移動ビークル１は原子炉内を遊泳移動し検査箇所近傍へ到達した後に、水平スラスタ８によりビークル前面側から後面側へ水流を生成させることで検査対象であるシュラウド４２に吸着し、ボールキャスタ１２と走行車輪９および距離計測ローラ１０を接触させる。次に押付けスラスタ２２により点検センサ２をシュラウド４２側へ押し付ける。
【００２２】
ビークル吸着後に搭載の傾斜センサ１３によりビークルの傾斜を計測し、傾いている場合には図示しない車輪駆動モータにより上下の走行車輪９を反対方向に駆動して水中移動ビークル１の姿勢を鉛直に補正する。そして図示しない車輪駆動モータにより走行車輪９を回転して走行移動する。
【００２３】
水中移動ビークル１はシュラウド４２に３点で接触しており、距離を一定に保ちながら水平に移動することができる。この時に傾斜センサ１３により水中移動ビークル１の傾斜を計測し、傾斜している場合には上下の走行車輪９の回転速度を調整し制御することで姿勢を垂直に保ちながら水平に走行移動することができる。また、水中移動ビークル１を傾斜させて切返しながら移動することで上下方向にも移動することができる。
【００２４】
車輪９による走行時には距離計測ローラ１０も同時に回転するのでエンコーダ等の回転センサ１１により、吸着したシュラウド４２に対する水中移動ビークル１の走行距離すなわち点検センサ２の相対移動量を計測することができる。
【００２５】
次に図３を参照して点検センサ保持部３の構造および動作を説明する。図３にはシュラウド４２下方の炉下部において、シュラウドサポートリング５０とシュラウド下部胴４９を接合する水平溶接線５２近傍、あるいはシュラウドサポートリング５０とシュラウドサポートシリンダ５１を接合する水平溶接線５３近傍を検査する場合の点検センサ２の設置状態を示す。
【００２６】
水中移動ビークル１の下部にアーム２０がヒンジピン２４により回転可能に取付けられ、アーム２０の先端にはヒンジピン２５を介して取付けプレート２１が回転可能に取付けられている。点検センサ２の両側に配置された取付けプレート２１には軸受けを介して回転ローラ２３が取付けられ、点検センサ２の背中側には押付けスラスタ２２が配置されている。
【００２７】
水中移動ビークル１が炉心支持板４４を通過して炉下部に進入し、シュラウド下部胴４９に吸着した後に、押し付けスラスタ２２により回転ローラ２３をシュラウドサポートリング５０に押し当てる。これにより、シュラウド下部胴４９とシュラウドサポートリング５０の相対位置がずれている場合に、水中移動ビークル１の吸着面であるシュラウド下部胴４９に対するシュラウドサポートリング５０の出っ張り寸法が異なっても、点検センサ２を水平溶接線５２あるいは５３に対して一定距離に保ちながら水平に移動して検査を行うことができる。
【００２８】
なお、本実施の形態においては押付けスラスタ２２により前方に押し付けているが、スラスタの代わりにスプリングを用いてヒンジピン２４周りにアーム２０を前方に押し出す構造としてもよい。
【００２９】
次に、図４〜図６により位置決め治具３０の構成と運用方法について説明する。
図４は位置決め治具３０の構成を示す斜視図である。位置決め治具３０は、シュラウド４２内側の炉心支持板４４より下の炉下部において、シュラウドサポートリング５０の上側水平溶接線５２や下側水平溶接線５３の検査を行う場合に、シュラウド下部胴４９上での水中移動ビークル１の円周方向の基準位置を定める（図１，図３参照）。
【００３０】
位置決め治具３０は、燃料交換機ホイストなどを用いて上部のつかみ部３１により吊り下げ、上部格子板４３と炉心支持板４４を通過させＣＲＤハウジング４７上に着座部３７を着座させて設置する。つかみ部３１の下には炉心支持板４４上の位置決めピンと嵌まり合う位置決めピンガイド３３と、方位調整板３２およびクランプ機構３４が配置されており、さらにその下に図示しないエアシリンダにより前後に進退動作可能な円周方向位置決め板３５と上下方向位置決め板３６が配置されている。
【００３１】
図５に炉下部における位置決め治具３０の設置状態を示す。着座部３７がＣＲＤハウジング４７上に設置され、上部において炉心支持板４４に対してクランプ機構３４により固定保持されている。位置決め治具３０の設置後に、円周方向位置決め板３５を展開してシュラウド下部胴４９に押し当てて固定することにより、水中移動ビークル１の円周方向の基準位置とする。
【００３２】
図６に水中移動ビークル１の円周方向の位置決め方法を示す。位置決め治具３０は炉心支持板４４の最外周の穴を通して設置される。円周方向位置決め板３５の展開方向は、炉心支持板４４上の位置決めピン５４を基準としている。図６において、例えば炉心中心に対する円周方向位置決め板３５の展開方向と位置決めピン５４のなす角度がθ１の時には、図４に示した位置決めピンガイド３３を回転させて、目盛りを記載した方位調整板３２により展開方向と位置決めピンガイド３３のなす角度がθ１となるように調整して固定する。この角度がθ２の場合には同様にして位置決めピンガイド３３の位置を調整する。
【００３３】
このようにして位置決め治具３０を設置し円周方向位置決め板３５を展開してシュラウド下部胴４９に押し当てて固定する。そしてシュラウド下部胴４９に吸着させた水中移動ビークル１を水平に走行させ、円周方向位置決め板３５に接触した位置を円周方向の基準とする。また上下方向の位置についても水中移動ビークル１の上部を上下方向位置決め板３６に接触させ、その位置を上下方向の基準とする。
【００３４】
この位置を検査開始位置として水中移動ビークル１を反時計方向に走行させたり、反時計方向に一定距離だけ動いた後に位置決め治具３０を撤去して反時計方向に走行させて検査を行う。さらに検査終了位置の基準とすることもできる。
【００３５】
以上に述べた本発明の第１の実施の形態の原子炉内検査装置は、炉心部や炉下部での検査を行う際に、水中移動ビークル１を上部格子板４３や炉心支持板４４を通過させた後にスラスタで自由に遊泳させ吸着位置を遠隔で調整することができる。また、吸着後に走行車輪で任意位置へ移動させることも可能である。すなわち上部格子板４３や炉心支持板４４での進入位置から離れたところへ移動できるので、進入位置が限られていても一箇所から広範囲の検査を行うことができる。
【００３６】
また、炉下部では位置決め治具３０に水中移動ビークル１を機械的に接触させて位置設定を行うので、円周方向の基準を正確に設定し、再現性をもたせることができる。以上のことから原子炉内でシュラウド内側の溶接線などの検査を遠隔で行うことが可能となり短時間で広範囲の検査を行うことができ、特に炉下部では検査範囲の設定精度が向上し検査品質を向上させることができる。
【００３７】
次に本発明の第２の実施の形態の原子炉内検査装置を説明する。本実施の形態では点検センサ２として第１の実施の形態におけるフェーズドアレイ超音波探触子の代わりに目視検査用のカメラまたは渦流探傷用センサを搭載する。水中移動ビークル１は上部格子板４３や炉心支持板４４での進入位置から離れた位置の検査が可能であることから、進入位置が限られていても広範囲の検査が可能であり、壁面に吸着しながら走行するので壁面との距離を一定に保ちながらシュラウド４２等の各種検査を連続的に行うことができる。従って、原子炉内でシュラウド内側の上部格子板や炉心支持板より下の領域において、溶接線などの検査を遠隔で行うことが可能であり、短時間で広範囲の検査を行うことができる。
【００３８】
次に本発明の第３の実施の形態の原子炉内検査装置を説明する。本実施の形態では、位置決め治具３０の円周方向位置決め板３５に超音波式や渦電流式の距離センサを取付けた構成とする。水中移動ビークル１の側面からケーブル４を取り出している場合、水中移動ビークル１の位置設定時に円周方向位置決め板３５に水中移動ビークル１を接触させることができない。本実施の形態では距離センサを用いることにより、水中移動ビークル１を接触させないで接近した状態で水中移動ビークル１までの相対距離を測定することにより位置設定を行うことが可能になる。その結果、位置決め治具３０を一箇所に設置して両側の検査が可能になるので、検査要求箇所が離れている場合にも、間の一箇所に位置決め治具３０を設置すればよい。従って設置箇所を減らすことができ、作業能率が向上する。
【００３９】
次に本発明の第４の実施の形態の原子炉内検査装置を説明する。本実施の形態では位置決め治具３０の代わりに水中カメラを用いる。水中移動ビークル１の位置設定時に基準となる炉内構造物と水中移動ビークル１や点検センサ２の相対位置をこの水中カメラで撮影し、その画像から所望の位置に水中移動ビークル１が移動したことを判別する。基準となる構造物がある場合には位置決め治具３０が不要で、より取扱いやすい水中カメラのみで位置設定を行うことが可能であり、作業時間を短縮することができる。
【００４０】
次に本発明の第５の実施の形態の原子炉内検査装置を説明する。本実施の形態では位置決め治具３０の代わりに、搭載したカメラの向きが上下、水平方向に遠隔で調整可能であり、さらに調整した角度が計測可能な雲台と、この雲台に取付けられた水中カメラを用いる。炉下部において検査を行う場合、まず水中カメラを搭載した雲台を位置決めピン５４を基準として炉心支持板４４の穴に設置し（図６参照）、水中移動ビークル１が所望の位置にある時に、水中移動ビークル１や点検センサ２上に定めた基準となる標的が水中カメラの画像の中心に撮影される方向に水中カメラの向きを合わせておく。次に水中移動ビークル１を走行させてビークル１や点検センサ２上の基準となる標的が、撮像画面の中心に撮影されるまでビークル１を移動させる。この状態を確認することによりビークル１が所望の位置に移動していることを判別し、ビークル１の位置設定を行う。
【００４１】
本実施の形態によれば、雲台の上下、水平方向の角度を変えることで複数の位置に水中移動ビークル１の位置設定が可能である。従って位置設定作業を効率的に行い作業時間を短縮することができる。
【００４２】
次に本発明の第６の実施の形態の原子炉内検査装置を説明する。本実施の形態では位置決め治具３０の代わりに、搭載したレーザーマーカおよび水中カメラの向きが上下、水平方向に遠隔で調整可能であり、さらに調整した角度が計測可能な雲台と、この雲台に取付けられたレーザーマーカおよび水中カメラを用いる。
【００４３】
炉下部において検査を行う場合、まずレーザーマーカおよび水中カメラを搭載した雲台を位置決めピン５４を基準として炉心支持板４４の穴に設置し、水中移動ビークル１が所望の位置にある時に、水中移動ビークル１や点検センサ２上に定めた基準となる標的にレーザー光が照射される方向に雲台の向きを合わせておく。次に水中移動ビークル１を走行させ、水中移動ビークル１や点検センサ２上の基準となる標的にレーザー光が照射される位置に来るまで水中移動ビークルを移動させる。この状態を水中カメラで確認することにより水中移動ビークル１が所望の位置に移動していることを判別し、水中移動ビークル１の位置設定を行う。
【００４４】
本実施の形態によれば、雲台の上下、水平方向の角度を変えることで複数の位置に水中移動ビークル１の位置設定が可能である。従って位置設定作業を効率的に行い作業時間を短縮することができる。また、位置設定時の誤差はレーザー光の照射点と標的のずれであり、これは雲台と水中移動ビークル１の距離が異なっても変化することはないので、位置設定精度が向上し検査品質を高めることができる。
【００４５】
【発明の効果】
本発明によれば、原子炉圧力容器内に設けられたシュラウド等の炉内構造物の検査を作業性よく効率的に行うことができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態の原子炉内検査装置を原子炉に設置した状態を示す図。
【図２】本発明の第１の実施の形態の原子炉内検査装置を構成する水中移動ビークルを示し、（ａ）は正面図、（ｂ）は部分側面図。
【図３】本発明の第１の実施の形態の原子炉内検査装置を構成する水中移動ビークルに搭載する点検センサ保持部の側面図。
【図４】本発明の第１の実施の形態の原子炉内検査装置においてシュラウド円周方向の基準位置を定める位置決め治具の斜視図。
【図５】本発明の第１の実施の形態の原子炉内検査装置における位置決め治具の原子炉内設置状態を示す縦断面図。
【図６】本発明の第１の実施の形態の原子炉内検査装置において位置決め治具を用いた原子炉内円周方向の基準位置の設定方法を説明する平面図。
【符号の説明】
１…水中移動ビークル、２…点検センサ、３…点検センサ保持部、４…ケーブル、５…制御操作部、６…点検センサ出力処理部、７…上下スラスタ、８…水平スラスタ、９…走行車輪、１０…距離計測ローラ、１１…回転センサ、１２…ボールキャスタ、１３…傾斜センサ、１４…フロート、２０…アーム、２１…取付けプレート、２２…押付けスラスタ、２３…回転ローラ、２４…ヒンジピン、２５…ヒンジピン、３０…位置決め治具、３１…つかみ部、３２…方位調整板、３３…位置決めピンガイド、３４…クランプ機構、３５…円周方向位置決め板、３６…上下方向位置決め板、３７…着座部、４０…水、４１…原子炉圧力容器、４２…シュラウド、４３…上部格子板、４４…炉心支持版、４５…下鏡、４６…スタブチューブ、４７…ＣＲＤハウジング、４８…オペレーションフロア、４９…シュラウド下部胴、５０…シュラウドサポートリング、５１…シュラウドサポートシリンダ、５２…水平溶接線、５３…水平溶接線、５４…位置決めピン。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-reactor inspection apparatus and method for inspecting a reactor internal structure such as a shroud provided in a reactor pressure vessel.
[0002]
[Prior art]
In boiling water reactors, a shroud, which is a welded structure, is installed in the reactor pressure vessel, and welded to the core between the upper grid plate and the core support plate and to the lower part of the reactor below the core support plate. Part exists.
[0003]
Conventionally, in order to inspect and inspect welds existing in the core or the lower part of the core as described above, various inspection sensors and equipment are attached to the end of a long pole, and a person hangs from the upper part of the furnace, Work is performed while passing through the upper grid plate and core support plate. In addition, a manipulator and a feed mechanism for positioning and holding various inspection sensors are installed in a vertically long casing that can pass through the lattice of the upper lattice plate and the hole of the core support plate. It is installed on the lower CRD housing and performs various operations. Furthermore, in recent years, various automatic apparatuses for inspecting and inspecting nuclear reactors have been developed (see Patent Documents 1, 2, 3, and 4 below).
[0004]
[Patent Document 1]
JP-A-8-201568 [Patent Document 2]
Japanese Patent Laid-Open No. 11-14784 [Patent Document 3]
Japanese Patent Laid-Open No. 11-21878 [Patent Document 4]
Japanese Patent Laid-Open No. 2003-40194
[Problems to be solved by the invention]
When the inspection work inside the reactor is performed manually, the inspection range is limited to the vicinity of the lattice of the upper lattice plate that has passed the inspection sensor and the hole of the core support plate, so what is necessary for inspection along the shroud? Again, the inspection sensor must be pulled over the upper grid plate and hung again. Furthermore, since a long pole must be manipulated at a position as low as 25 m underwater, the workability is very poor, requiring a lot of time and labor. In addition, even when a long device is installed in the core or bottom of the furnace, the range that can be inspected from one installation position is limited. Since it had to be lifted to the top and then moved to the next installation position, this was also a time consuming and labor intensive work.
[0006]
The present invention has been made in response to such a conventional situation, and an in-reactor inspection capable of efficiently and efficiently inspecting a reactor internal structure such as a shroud provided in a reactor pressure vessel. An object is to provide an apparatus and method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an in-reactor inspection apparatus according to a first aspect of the present invention includes an underwater mobile vehicle that moves in a three-dimensional direction in a nuclear reactor in which water is stored, and an inspection sensor holding unit attached to the underwater mobile vehicle. An inspection sensor installed in the reactor, positioning means provided in the reactor as a reference for the position of the underwater mobile vehicle relative to the in-reactor structure, and operation of the underwater mobile vehicle provided outside the reactor. A control operation unit and an inspection sensor output signal processing unit that receives and processes the output signal of the inspection sensor are provided.
[0008]
The invention of claim 2 is characterized in that the underwater vehicle has an upper and lower thruster that generates a thrust along the vertical direction of the nuclear reactor, a horizontal thruster that generates a thrust along the horizontal direction of the nuclear reactor, a float that generates buoyancy, and an inclination. It is set as the structure provided with the inclination sensor which detects this, the wheel which drive | works the surface of a furnace internal structure, and the distance meter which measures the distance of the said driving | running | working.
[0009]
According to a third aspect of the present invention, the inspection sensor is a visual inspection camera, a volume inspection ultrasonic sensor, or an eddy current flaw detection sensor.
According to a fourth aspect of the present invention, the inspection sensor holding part supports the inspection sensor so as to be movable close to and away from the adsorption surface of the underwater moving vehicle to the in-furnace structure, and maintains a distance to the adsorption surface. A roller or a universal wheel and a pressing means against the suction surface are provided, and the inspection sensor is kept at a predetermined distance from the in-furnace structure.
[0010]
According to a fifth aspect of the present invention, the means for pressing the suction surface is a thruster or a spring.
According to a sixth aspect of the present invention, the positioning means is a jig installed in a specific in-reactor structure in a nuclear reactor, and the underwater moving vehicle is mechanically brought into contact with the jig and the in-reactor structure The position of the underwater moving vehicle with respect to is set.
[0011]
The invention of claim 7 is characterized in that the positioning means includes a distance sensor provided on a jig installed in a specific in-reactor structure in a nuclear reactor, and the underwater moving vehicle approaches the jig. The distance sensor is configured to set the position of the underwater moving vehicle relative to the in-furnace structure by measuring a relative distance to the underwater moving vehicle or the inspection sensor.
[0012]
The invention according to claim 8 is characterized in that the positioning means includes an underwater camera installed in a specific in-reactor structure in a nuclear reactor, and a relative position between the specific in-reactor structure and the underwater moving vehicle or the inspection sensor. Is taken by the underwater camera, and it is determined from the image that the underwater moving vehicle is located at a predetermined position, and the position of the underwater moving vehicle is set.
[0013]
According to a ninth aspect of the present invention, the positioning means includes an underwater camera that is installed in a specific in-reactor structure in a nuclear reactor and whose imaging region is known, and the underwater moving vehicle is located at a reference position in an image of the underwater camera. Or it is set as the structure which confirms that the target on the said inspection sensor is imaged, determines that the said underwater movement vehicle is located in the predetermined position, and sets the position of the underwater movement vehicle.
[0014]
The invention of claim 10 is characterized in that the positioning means includes a laser marker and an underwater camera installed in a specific in-reactor structure in the nuclear reactor, and sets a laser irradiation position on the in-reactor structure in advance. The underwater camera confirms that the laser is irradiated to the target on the underwater vehicle or the inspection sensor, and determines that the underwater vehicle is located at a predetermined position. The position is set.
[0015]
The invention of claim 11 is an in-reactor inspection method, and in the in-reactor inspection apparatus of claim 2, the control operation unit is operated to adsorb the underwater moving vehicle to the in-reactor structure by the horizontal thruster. The wheel is moved on the in-furnace structure by the wheel to inspect the in-furnace structure.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An in-reactor inspection apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a conceptual diagram showing a case in which an inner shell and an inner surface of a lower shell of a shroud 42 which is a reactor internal structure in a boiling water reactor are inspected by the in-reactor inspection apparatus of the present embodiment.
[0017]
As shown in FIG. 1, a cable 4 is connected to the underwater mobile vehicle 1 on which the inspection sensor 2 is mounted. The cable 4 is connected to a control operation unit 5 installed on an operation floor 48 or a fuel changer. The inspection sensor output processing unit 6 is connected. A positioning jig 30 is provided on a CRD (control rod drive mechanism) housing 47 at the lower part of the furnace to determine a reference position in the circumferential direction of the pressure vessel of the underwater mobile vehicle 1 on the shroud lower body 49. Further, the control operation unit 5 and the inspection sensor output processing unit 6 are connected to each other for exchanging information such as inspection position data.
[0018]
When the inspection at the lower part of the reactor is performed, the underwater mobile vehicle 1 equipped with the inspection sensor 2 is introduced into the reactor from above the reactor pressure vessel 41, submerged while swimming, and passes through the upper lattice plate 43 and the core support plate 44. To reach the bottom of the furnace. Next, the inspection start position on the lower body is determined by the positioning jig 30, and the inspection sensor 2 is conveyed to the inspection location by the underwater moving vehicle 1 to start the inspection.
[0019]
FIG. 2 shows the configuration of the underwater vehicle 1. As shown in FIG. 2, a pair of upper and lower thrusters 7 are disposed on the upper part of the underwater moving vehicle 1 by being inclined at the same angle to the left and right, and a pair of horizontal thrusters 8 are disposed at the center. Further, in order to travel on the shroud 42, the ball caster 12, two traveling wheels 9 and two distance measuring rollers 10 are arranged on the opposite side of the ball caster 12. In addition, an inclination sensor 13 is provided at the center lower part. The inspection sensor 2 is a phased array ultrasonic probe, and is attached to the lower part of the underwater moving vehicle 1 by an inspection sensor holding unit 3. The inspection sensor 2 is suspended by two arms 20 via a mounting plate 21.
[0020]
The underwater mobile vehicle 1 performs submergence, levitation, and right / left swimming by manipulating the rotation direction of each rotary blade of the pair of upper and lower thrusters 7 and combining the direction of water flow. The pair of horizontal thrusters 8 move forward, reverse, and swivel around the vertical axis. A float 14 is disposed on the upper side of the underwater moving vehicle 1 and is adjusted so that its own weight and buoyancy in water are balanced, so that after passing through the upper lattice plate 43 and the core support plate 44, it swims to the side and shrouds. 42 It can go to the inner surface. Further, since the center of buoyancy is higher than the center of gravity in water, the inspection sensor 2 is always held downward when the vehicle is stopped and the posture during swimming by the horizontal thruster 8 can be stabilized. .
[0021]
The underwater mobile vehicle 1 swims in the reactor and reaches the vicinity of the inspection location, and then generates a water flow from the front side of the vehicle to the rear side by the horizontal thruster 8 so as to be adsorbed to the shroud 42 to be inspected and the ball caster 12 And the traveling wheel 9 and the distance measuring roller 10 are brought into contact with each other. Next, the inspection sensor 2 is pressed against the shroud 42 by the pressing thruster 22.
[0022]
The inclination of the vehicle is measured by the mounted inclination sensor 13 after the vehicle is adsorbed, and when it is inclined, the upper and lower traveling wheels 9 are driven in opposite directions by a wheel drive motor (not shown) to vertically correct the attitude of the underwater vehicle 1. To do. Then, the traveling wheel 9 is rotated and moved by a wheel drive motor (not shown).
[0023]
The underwater vehicle 1 is in contact with the shroud 42 at three points, and can move horizontally while keeping the distance constant. At this time, the inclination of the underwater mobile vehicle 1 is measured by the inclination sensor 13, and if it is inclined, the rotational speed of the upper and lower traveling wheels 9 is adjusted and controlled to move horizontally while keeping the posture vertical. Can do. Further, it is possible to move in the vertical direction by moving the underwater moving vehicle 1 while tilting and turning it.
[0024]
Since the distance measuring roller 10 also rotates at the same time when traveling by the wheel 9, the traveling distance of the underwater moving vehicle 1 relative to the attracted shroud 42, that is, the relative movement amount of the inspection sensor 2 can be measured by the rotation sensor 11 such as an encoder.
[0025]
Next, the structure and operation of the inspection sensor holding unit 3 will be described with reference to FIG. In FIG. 3, the vicinity of the horizontal weld line 52 that joins the shroud support ring 50 and the shroud lower body 49 or the vicinity of the horizontal weld line 53 that joins the shroud support ring 50 and the shroud support cylinder 51 is inspected in the lower part of the furnace below the shroud 42. The installation state of the inspection sensor 2 in the case of performing is shown.
[0026]
An arm 20 is rotatably attached to the lower part of the underwater moving vehicle 1 by a hinge pin 24, and an attachment plate 21 is rotatably attached to the tip of the arm 20 via a hinge pin 25. A rotation roller 23 is attached to the mounting plates 21 arranged on both sides of the inspection sensor 2 via bearings, and a pressing thruster 22 is arranged on the back side of the inspection sensor 2.
[0027]
After the underwater moving vehicle 1 passes through the core support plate 44 and enters the lower part of the furnace and is adsorbed by the shroud lower body 49, the rotating roller 23 is pressed against the shroud support ring 50 by the pressing thruster 22. As a result, when the relative positions of the shroud lower body 49 and the shroud support ring 50 are shifted, the inspection sensor is different even if the protruding dimensions of the shroud support ring 50 with respect to the shroud lower body 49 serving as the suction surface of the underwater moving vehicle 1 are different. The inspection can be performed by moving 2 horizontally while maintaining 2 at a fixed distance from the horizontal welding line 52 or 53.
[0028]
In the present embodiment, the pressing thruster 22 is used to push forward, but a structure may be used in which the arm 20 is pushed forward around the hinge pin 24 using a spring instead of the thruster.
[0029]
Next, the configuration and operation method of the positioning jig 30 will be described with reference to FIGS.
FIG. 4 is a perspective view showing the configuration of the positioning jig 30. The positioning jig 30 is provided on the shroud lower shell 49 when the upper horizontal welding line 52 and the lower horizontal welding line 53 of the shroud support ring 50 are inspected in the lower part of the furnace below the core support plate 44 inside the shroud 42. The reference position in the circumferential direction of the underwater mobile vehicle 1 is determined (see FIGS. 1 and 3).
[0030]
The positioning jig 30 is hung by an upper grip 31 using a fuel exchanger hoist or the like, passes through the upper lattice plate 43 and the core support plate 44, and is seated on the CRD housing 47. A positioning pin guide 33 that fits with a positioning pin on the core support plate 44, an orientation adjustment plate 32, and a clamp mechanism 34 are disposed below the grip portion 31, and further forward and backward by an air cylinder (not shown). An operable circumferential positioning plate 35 and vertical positioning plate 36 are disposed.
[0031]
FIG. 5 shows an installation state of the positioning jig 30 in the lower part of the furnace. A seating portion 37 is installed on the CRD housing 47 and is fixedly held by the clamp mechanism 34 to the core support plate 44 at the upper portion. After the positioning jig 30 is installed, the circumferential positioning plate 35 is developed and pressed against the shroud lower body 49 to be fixed, thereby setting the circumferential position of the underwater mobile vehicle 1.
[0032]
FIG. 6 shows a circumferential positioning method of the underwater vehicle 1. The positioning jig 30 is installed through the outermost peripheral hole of the core support plate 44. The deployment direction of the circumferential positioning plate 35 is based on the positioning pins 54 on the core support plate 44. In FIG. 6, for example, when the angle formed by the positioning direction of the circumferential positioning plate 35 with respect to the core center and the positioning pin 54 is θ1, the positioning pin guide 33 shown in FIG. 32 is adjusted and fixed so that the angle formed by the developing direction and the positioning pin guide 33 is θ1. When this angle is θ2, the position of the positioning pin guide 33 is adjusted in the same manner.
[0033]
In this way, the positioning jig 30 is installed and the circumferential positioning plate 35 is developed and pressed against the shroud lower body 49 to be fixed. Then, the underwater moving vehicle 1 adsorbed on the shroud lower body 49 is caused to travel horizontally, and the position in contact with the circumferential positioning plate 35 is used as a reference in the circumferential direction. As for the vertical position, the upper part of the underwater vehicle 1 is brought into contact with the vertical positioning plate 36, and the position is used as the vertical reference.
[0034]
With this position as the inspection start position, the underwater vehicle 1 is run counterclockwise, or after moving a certain distance in the counterclockwise direction, the positioning jig 30 is removed and run counterclockwise for inspection. Furthermore, it can be used as a reference for the inspection end position.
[0035]
The in-reactor inspection apparatus according to the first embodiment of the present invention described above passes the underwater mobile vehicle 1 through the upper lattice plate 43 and the core support plate 44 when performing the inspection at the core portion and the lower portion of the reactor. It is possible to adjust the adsorption position remotely by allowing it to swim freely with a thruster. Moreover, it is also possible to move to an arbitrary position with a traveling wheel after adsorption | suction. That is, since the upper grid plate 43 and the core support plate 44 can be moved away from the entry position, a wide range of inspections can be performed from one place even if the entry position is limited.
[0036]
In addition, since the position is set by mechanically contacting the underwater moving vehicle 1 with the positioning jig 30 at the lower part of the furnace, the reference in the circumferential direction can be set accurately and reproducibility can be provided. From the above, it is possible to remotely inspect the inside of the shroud within the nuclear reactor and perform a wide range of inspections in a short time. Can be improved.
[0037]
Next, the in-reactor inspection apparatus according to the second embodiment of the present invention will be described. In the present embodiment, a camera for visual inspection or a sensor for eddy current flaw detection is mounted as the inspection sensor 2 instead of the phased array ultrasonic probe in the first embodiment. Since the underwater mobile vehicle 1 can inspect the position apart from the entry position on the upper grid plate 43 and the core support plate 44, it can inspect a wide range even if the entry position is limited, and is adsorbed on the wall surface. Therefore, various inspections such as the shroud 42 can be continuously performed while keeping the distance from the wall surface constant. Therefore, it is possible to remotely inspect the weld line and the like in the region below the upper grid plate and the core support plate inside the shroud in the nuclear reactor, and a wide range of inspections can be performed in a short time.
[0038]
Next, an in-reactor inspection apparatus according to a third embodiment of the present invention will be described. In the present embodiment, an ultrasonic type or eddy current type distance sensor is attached to the circumferential positioning plate 35 of the positioning jig 30. When the cable 4 is taken out from the side surface of the underwater vehicle 1, the underwater vehicle 1 cannot be brought into contact with the circumferential positioning plate 35 when the position of the underwater vehicle 1 is set. In the present embodiment, by using the distance sensor, it is possible to set the position by measuring the relative distance to the underwater moving vehicle 1 in a state where the underwater moving vehicle 1 is approached without being brought into contact therewith. As a result, the positioning jig 30 can be installed at one place and inspection on both sides can be performed. Therefore, the positioning jig 30 can be installed at one place even when the inspection requesting places are separated. Accordingly, the number of installation locations can be reduced, and work efficiency can be improved.
[0039]
Next, an in-reactor inspection apparatus according to a fourth embodiment of the present invention will be described. In this embodiment, an underwater camera is used instead of the positioning jig 30. The relative position of the in-furnace structure and the underwater mobile vehicle 1 or the inspection sensor 2 used as a reference when setting the position of the underwater mobile vehicle 1 is photographed by the underwater camera, and the underwater mobile vehicle 1 has moved to a desired position from the image. Is determined. When there is a reference structure, the positioning jig 30 is unnecessary, and the position can be set only by an underwater camera that is easier to handle, and the working time can be shortened.
[0040]
Next, an in-reactor inspection apparatus according to a fifth embodiment of the present invention will be described. In this embodiment, instead of the positioning jig 30, the orientation of the mounted camera can be adjusted remotely in the vertical and horizontal directions, and a pan head capable of measuring the adjusted angle, and the pan head attached to the pan head. Use an underwater camera. When inspecting in the lower part of the furnace, first, a pan head equipped with an underwater camera is installed in the hole of the core support plate 44 with reference to the positioning pin 54 (see FIG. 6), and when the underwater mobile vehicle 1 is at a desired position, The direction of the underwater camera is aligned with the direction in which the target set as a reference on the underwater moving vehicle 1 and the inspection sensor 2 is photographed at the center of the image of the underwater camera. Next, the vehicle 1 is moved until the vehicle 1 or the inspection sensor 2 as a reference target is photographed at the center of the imaging screen. By confirming this state, it is determined that the vehicle 1 has moved to a desired position, and the position of the vehicle 1 is set.
[0041]
According to the present embodiment, it is possible to set the position of the underwater mobile vehicle 1 at a plurality of positions by changing the vertical and horizontal angles of the camera platform. Therefore, it is possible to efficiently perform the position setting work and shorten the work time.
[0042]
Next, an in-reactor inspection apparatus according to a sixth embodiment of the present invention will be described. In this embodiment, instead of the positioning jig 30, the direction of the mounted laser marker and the underwater camera can be adjusted remotely in the vertical and horizontal directions, and a pan head capable of measuring the adjusted angle, and the pan head Use a laser marker and underwater camera attached to the camera.
[0043]
When the inspection is performed in the lower part of the furnace, first, a pan head equipped with a laser marker and an underwater camera is installed in the hole of the core support plate 44 with the positioning pin 54 as a reference, and the underwater moving vehicle 1 moves underwater when it is in a desired position. The direction of the camera platform is aligned with the direction in which the laser beam is irradiated to the reference target set on the vehicle 1 or the inspection sensor 2. Next, the underwater moving vehicle 1 is caused to travel, and the underwater moving vehicle 1 is moved until it reaches a position where laser light is irradiated to a reference target on the underwater moving vehicle 1 and the inspection sensor 2. By confirming this state with the underwater camera, it is determined that the underwater moving vehicle 1 has moved to a desired position, and the position of the underwater moving vehicle 1 is set.
[0044]
According to the present embodiment, it is possible to set the position of the underwater mobile vehicle 1 at a plurality of positions by changing the vertical and horizontal angles of the camera platform. Therefore, it is possible to efficiently perform the position setting work and shorten the work time. In addition, the error at the time of position setting is the difference between the irradiation point of the laser beam and the target, which does not change even if the distance between the camera platform and the underwater mobile vehicle 1 is different, so that the position setting accuracy is improved and the inspection quality is improved. Can be increased.
[0045]
【The invention's effect】
According to the present invention, it is possible to efficiently inspect a reactor internal structure such as a shroud provided in a reactor pressure vessel with good workability.
[Brief description of the drawings]
FIG. 1 is a diagram showing a state where an in-reactor inspection apparatus according to a first embodiment of the present invention is installed in a nuclear reactor.
FIGS. 2A and 2B show an underwater mobile vehicle constituting the in-reactor inspection apparatus according to the first embodiment of the present invention, wherein FIG. 2A is a front view, and FIG. 2B is a partial side view.
FIG. 3 is a side view of an inspection sensor holding unit mounted on an underwater mobile vehicle constituting the in-reactor inspection apparatus according to the first embodiment of the present invention.
FIG. 4 is a perspective view of a positioning jig for determining a reference position in a shroud circumferential direction in the in-reactor inspection apparatus according to the first embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing an installation state of a positioning jig in the reactor in the in-reactor inspection apparatus according to the first embodiment of the present invention.
FIG. 6 is a plan view for explaining a method for setting a reference position in the circumferential direction in the reactor using a positioning jig in the in-reactor inspection apparatus according to the first embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Underwater vehicle, 2 ... Inspection sensor, 3 ... Inspection sensor holding part, 4 ... Cable, 5 ... Control operation part, 6 ... Inspection sensor output process part, 7 ... Vertical thruster, 8 ... Horizontal thruster, 9 ... Running wheel DESCRIPTION OF SYMBOLS 10 ... Distance measuring roller, 11 ... Rotation sensor, 12 ... Ball caster, 13 ... Inclination sensor, 14 ... Float, 20 ... Arm, 21 ... Mounting plate, 22 ... Pushing thruster, 23 ... Rotating roller, 24 ... Hinge pin, 25 DESCRIPTION OF SYMBOLS ... Hinge pin, 30 ... Positioning jig, 31 ... Grazing part, 32 ... Direction adjustment plate, 33 ... Positioning pin guide, 34 ... Clamp mechanism, 35 ... Circumferential direction positioning plate, 36 ... Vertical direction positioning plate, 37 ... Seating part , 40 ... water, 41 ... reactor pressure vessel, 42 ... shroud, 43 ... upper lattice plate, 44 ... core support plate, 45 ... lower mirror, 46 ... stub tube, 47 ... RD housing, 48 ... operation floor, 49 ... shroud lower cylinder, 50 ... shroud support ring, 51 ... shroud support cylinder, 52 ... horizontal welding line, 53 ... horizontal welding line, 54 ... positioning pins.

Claims

An underwater mobile vehicle that moves in a three-dimensional direction in a nuclear reactor in which water is stored, an inspection sensor attached to the underwater mobile vehicle via an inspection sensor holding unit, and an in-reactor structure provided in the reactor Positioning means that serves as a reference for the position of the underwater mobile vehicle, a control operation unit that is provided outside the reactor and controls the operation of the underwater mobile vehicle, and an inspection sensor output that receives and processes an output signal of the inspection sensor An in-reactor inspection apparatus comprising a signal processing unit.

The underwater vehicle includes an upper and lower thruster that generates a thrust along the vertical direction of the reactor, a horizontal thruster that generates a thrust along the horizontal direction of the reactor, a float that generates buoyancy, and an inclination sensor that detects inclination. The in-reactor inspection apparatus according to claim 1, further comprising a wheel that travels on a surface of the in-reactor structure and a distance meter that measures the travel distance.

The in-reactor inspection apparatus according to claim 1, wherein the inspection sensor is a visual inspection camera, a volume inspection ultrasonic sensor, or an eddy current flaw detection sensor.

The inspection sensor holding unit supports the inspection sensor so as to be movable close to and away from the suction surface of the underwater mobile vehicle to the in-furnace structure, and maintains a distance to the suction surface. 2. The in-reactor inspection apparatus according to claim 1, further comprising: a pressing unit that presses the suction surface, wherein the inspection sensor is maintained at a predetermined distance from the in-reactor structure.

5. The in-reactor inspection apparatus according to claim 4, wherein the means for pressing the adsorption surface is a thruster or a spring.

The positioning means is a jig installed in a specific in-reactor structure in a nuclear reactor, and the underwater moving vehicle is positioned relative to the in-reactor structure by mechanically contacting the underwater moving vehicle with the jig. The in-reactor inspection apparatus according to claim 1, wherein:

The positioning means includes a distance sensor provided on a jig installed in a specific in-reactor structure in a nuclear reactor, the underwater moving vehicle is brought close to the jig, and the underwater movement is performed by the distance sensor. The in-reactor inspection apparatus according to claim 1, wherein the position of the underwater moving vehicle relative to the in-reactor structure is set by measuring a relative distance to the vehicle or the inspection sensor.

The positioning means includes an underwater camera installed in a specific in-reactor structure in a nuclear reactor, and images the relative position of the specific in-reactor structure and the underwater moving vehicle or the inspection sensor with the underwater camera. 2. The in-reactor inspection apparatus according to claim 1, wherein the position of the underwater mobile vehicle is determined by determining from the image that the underwater mobile vehicle is located at a predetermined position.

The positioning means includes an underwater camera that is installed in a specific in-reactor structure in a nuclear reactor and whose imaging region is known, and the target on the underwater moving vehicle or the inspection sensor is located at a reference position in the image of the underwater camera. 2. The interior of the nuclear reactor according to claim 1, wherein the position of the underwater mobile vehicle is set by confirming that the underwater mobile vehicle is located at a predetermined position. Inspection device.

The positioning means includes a laser marker and an underwater camera installed on a specific in-reactor structure in a nuclear reactor, and sets a laser irradiation position on the in-reactor structure in advance, and the underwater moving vehicle or the inspection Confirming that the target on the sensor is irradiated with the laser with the underwater camera, determining that the underwater moving vehicle is located at a predetermined position, and setting the position of the underwater moving vehicle. The in-reactor inspection apparatus according to claim 1, characterized in that:

3. The in-reactor inspection apparatus according to claim 2, wherein the underwater vehicle is adsorbed on the in-reactor structure by the horizontal thruster by operating the control operation unit and moved on the in-reactor structure by the wheel. An in-reactor inspection method comprising inspecting the in-reactor structure.