JP4234631B2

JP4234631B2 - Method for decontamination and disassembly of cylindrical structure

Info

Publication number: JP4234631B2
Application number: JP2004110636A
Authority: JP
Inventors: 順英佐藤
Original assignee: 株式会社エイブル
Priority date: 2004-04-05
Filing date: 2004-04-05
Publication date: 2009-03-04
Anticipated expiration: 2024-04-05
Also published as: JP2005292063A

Description

この発明は、内周面が放射能汚染された熱交換器、配管等の円筒状構造物について除染および解体を行う方法に関し、装置を共用して除染および解体を行うようにしたものである。 The present invention relates to a method for decontamination and disassembly of cylindrical structures such as heat exchangers and pipes whose inner peripheral surface is radioactively contaminated. is there.

老朽化した原子力プラントの廃止措置に伴い、該プラント内設備機器の廃棄方法が検討されている。廃棄方法として、機器を解体し、解体物全部を廃棄する方法が考えられる。しかし、この方法では大量の廃棄物が発生し、廃棄に膨大な費用がかかるうえに、解体物の再利用ができない。そこで、機器の放射能汚染された表面を除染（付着した放射性物質を除去すること）したうえで解体する（あるいは解体したうえで除染する）方法が検討されている。この方法によれば、廃棄物を減量しかつ解体物の再利用も可能となる。 Along with the decommissioning of an aging nuclear plant, a method for disposing of equipment in the plant is being studied. As a disposal method, a method of dismantling the equipment and discarding all the dismantled materials is conceivable. However, this method generates a large amount of waste, and enormous costs are required for disposal, and the dismantled material cannot be reused. In view of this, a method for decontamination (or decontamination after disassembly) after decontaminating (removing attached radioactive substances) the surface of the device that has been radioactively contaminated has been studied. According to this method, the amount of waste can be reduced and the dismantled material can be reused.

除染方法として、従来は、除染溶液を使用して除染を行う化学除染法、研磨材を吹きつけて表面を削って除染するブラスト法等が提案されていた。化学除染法としては例えば下記特許文献１に記載された方法があった。ブラスト法としては例えば下記特許文献２に記載された方法があった。 Conventionally, as a decontamination method, a chemical decontamination method for decontamination using a decontamination solution, a blasting method for decontamination by blowing an abrasive and scraping the surface, and the like have been proposed. As a chemical decontamination method, for example, there was a method described in Patent Document 1 below. As a blasting method, for example, there is a method described in Patent Document 2 below.

特開平１１−１０９０９４号公報Japanese Patent Laid-Open No. 11-109094 特開２０００−７５０９５号公報JP 2000-75095 A

従来の除染と解体には別々の装置が必要であった。この発明は上述の点に鑑みてなされたもので、装置を共用して除染および解体を行うようにした除染および解体方法を提供しようとするものである。 Conventional decontamination and disassembly required separate equipment. The present invention has been made in view of the above-described points, and an object of the present invention is to provide a decontamination and disassembly method that performs decontamination and disassembly using a common apparatus.

この発明の円筒状構造物の除染および解体方法は、内周面（１４ｂ）が放射能汚染された円筒状構造物（１４）の外周面（１４ａ）を取り囲むように該外周面（１４ａ）に装着される固定部（４６）と、該固定部（４６）に回転自在に支持されて動力（５８）により前記円筒状構造物（１４）の外周面（１４ａ）の回りを回転する回転部（４８）と、該回転部（４８）に装着された刃物台（６６，７４）と、該刃物台（６６，７４）に装着された切削刃物（７２，８４）とを具備する切削加工機（４４）を使用し、前記円筒状構造物（１４）の開口端部（１４ｃ）から切削刃物（８４）を差し入れて該切削刃物（８４）を該円筒状構造物（１４）の内周面（１４ｂ）に対面させ、前記回転部（４８）を回転させるとともに該切削刃物（８４）を該円筒状構造物（１４）の軸方向に送ることにより該切削刃物（８４）で該円筒状構造物（１４）の内周面（１４ｂ）を切削して該内周面（１４ｂ）の除染を行い、前記円筒状構造物（１４）の外周面（１４ａ）に切削刃物（７２）を対面させ、前記回転部（４８）を回転させるとともに該切削刃物（７２）を該円筒状構造物（１４）の径方向内方向に送ることにより該切削刃物（７２）で該円筒状構造物（１４）を外側から切削し切断して該円筒状構造物（１４）の解体を行うものである。 In the method for decontamination and dismantling of the cylindrical structure according to the present invention, the outer peripheral surface (14a) is such that the inner peripheral surface (14b) surrounds the outer peripheral surface (14a) of the cylindrical structure (14) that is radioactively contaminated. A fixed portion (46) to be mounted on the rotating portion, and a rotating portion that is rotatably supported by the fixed portion (46) and rotates around the outer peripheral surface (14a) of the cylindrical structure (14) by power (58). (48), a cutting tool (66, 74) mounted on the rotating part (48), and a cutting tool (72, 84) mounted on the tool rest (66, 74). (44) is used, the cutting blade (84) is inserted from the open end (14c) of the cylindrical structure (14), and the cutting blade (84) is inserted into the inner peripheral surface of the cylindrical structure (14). (14b), the rotating part (48) is rotated and the cutting blade (84) The inner peripheral surface (14b) of the cylindrical structure (14) is cut by the cutting blade (84) by feeding it in the axial direction of the cylindrical structure (14) to remove the inner peripheral surface (14b). Dyeing is performed, the cutting blade (72) is opposed to the outer peripheral surface (14a) of the cylindrical structure (14), the rotating portion (48) is rotated, and the cutting blade (72) is moved to the cylindrical structure. The cylindrical structure (14) is disassembled by cutting the cylindrical structure (14) from the outside with the cutting blade (72) by cutting it inward in the radial direction of (14). .

この発明はさらに、前記内周面（１４ｂ）の除染を行うときは、前記刃物台として、前記円筒状構造物（１４）の開口端部（１４ｃ）から切削刃物（８４）を差し入れて該切削刃物（８４）を該円筒状構造物（１４）の内周面（１４ｂ）に対面させかつ該切削刃物（８４）を該円筒状構造物（１４）の軸方向に送ることができる内周面切削用刃物台（７４）を使用し、前記解体を行うときは、前記刃物台として、前記円筒状構造物（１４）の外周面（１４ａ）に切削刃物（７２）を対面させかつ該切削刃物（７２）を該円筒状構造物（１４）の径方向内方向に送ることができる外周面切削用刃物台（６６）を使用するものである。 In the present invention, when the inner peripheral surface (14b) is decontaminated, a cutting tool (84) is inserted from the opening end (14c) of the cylindrical structure (14) as the tool post. Inner circumference that allows the cutting blade (84) to face the inner peripheral surface (14b) of the cylindrical structure (14) and feed the cutting blade (84) in the axial direction of the cylindrical structure (14) When the surface cutting tool post (74) is used and the disassembly is performed, the cutting tool (72) faces the outer peripheral surface (14a) of the cylindrical structure (14) as the tool post and the cutting is performed. it is to use blade (72) of the cylindrical structure (14) outer peripheral surface cutting tool rest that can be sent in a radial direction in the direction of the (66).

この発明はさらに、前記円筒状構造物（１４）の内周面（１４ｂ）について該円筒状構造物（１４）の開口端部（１４ｃ）から軸方向奥方向の所定幅にわたり前記除染を行い、該除染後、該円筒状構造物（１４）の外周面（１４ａ）に対する前記切削加工機（４４）の固定部（４６）の装着位置を、内周面（１４ｂ）の除染が済んでいる位置に設定される切断予定位置（Ｃ３，Ｃ４，…，Ｃｎ）よりも軸方向奥側に移動して、該切断予定位置（Ｃ３，Ｃ４，…，Ｃｎ）で前記切断を行い、該切断後、前記切削加工機（４４）の固定部（４６）の装着位置はそのままで、該円筒状構造物（１４）の内周面（１４ｂ）について該円筒状構造物（１４）の新たな開口端部（１４ｃ’）から軸方向奥方向の所定幅にわたり前記除染を行うものである。 The present invention further performs the decontamination of the inner peripheral surface (14b) of the cylindrical structure (14) over a predetermined width in the axial depth direction from the open end (14c) of the cylindrical structure (14). After the decontamination, the mounting position of the fixing portion (46) of the cutting machine (44) with respect to the outer peripheral surface (14a) of the cylindrical structure (14) is decontaminated on the inner peripheral surface (14b). Moving to the back side in the axial direction from the planned cutting position (C3, C4,..., Cn) set at the position where the cutting is performed, and performing the cutting at the planned cutting position (C3, C4,..., Cn), After cutting, the mounting position of the fixed part (46) of the cutting machine (44) remains unchanged, and the cylindrical structure (14) is renewed with respect to the inner peripheral surface (14b) of the cylindrical structure (14). open end from (14c ') over the axial inner direction of the predetermined width is performed the decontamination.

前記除染工程、固定部の移動工程、切断工程のサイクルを適宜回数繰り返すことができる。 The cycle of the decontamination process, the fixing part moving process, and the cutting process can be repeated as appropriate.

この発明の円筒状構造物の除染および解体方法は、円筒状本体胴（１４）の内部が放射能汚染された熱交換器（１０）を除染し解体する方法であって、前記本体胴（１４）の外周面（１４ａ）を取り囲むように該外周面（１４ａ）に装着される固定部（４６）と、該固定部（４６）に回転自在に支持されて動力（５８）により前記本体胴（１４）の外周面（１４ａ）の回りを回転する回転部（４６）と、該回転部（４６）に装着された刃物台（６６，７４）と、該刃物台（６６，７４）に装着された切削刃物（７２，８４）とを具備する切削加工機（４４）を使用し、該切削加工機（４４）の固定部（４６）を前記本体胴（１４）の、管板（１６）よりも奥側の、伝熱管束（２６）が配置されている側の位置に装着し、前記刃物台として前記本体胴（１４）の外周面（１４ａ）に切削刃物（７２）を対面させかつ該切削刃物（７２）を該本体胴（１４）の径方向内方向に送ることができる外周面切削用刃物台（６６）を使用し、前記固定部（４６）の装着位置と前記管板（１６）の位置との間の位置で、該本体胴（１４）の外周面（１４ａ）に切削刃物（７２）を対面させ、前記回転部（４８）を回転させるとともに該切削刃物（７２）を該本体胴（１４）の径方向内方向に送ることにより該切削刃物（７２）で該本体胴（１４）を外側から切削して切断し、該切断後、前記伝熱管束（２６）を前記管板（１６）ごと前記本体胴（１４）から抜き出し、該抜き出し後、前記固定部（４６）の装着位置はそのままで、前記刃物台として前記本体胴（１４）の切断で形成された開口端部（１４ｃ）から切削刃物（８４）を差し入れて該切削刃物（８４）を該本体胴（１４）の内周面（１４ｂ）に対面させかつ該切削刃物（８４）を該本体胴（１４）の軸方向に送ることができる内周面切削用刃物台（７４）を使用し、該本体胴（１４）の前記開口端部（１４ｃ）から切削刃物（８４）を差し入れて該切削刃物（８４）を該本体胴（１４）の内周面（１４ｂ）に対面させ、前記回転部（４８）を回転させるとともに該切削刃物（８４）を該本体胴（１４）の軸方向に送ることにより、該切削刃物（８４）で該本体胴（１４）の内周面（１４ｂ）を切削して該内周面（１４ｂ）の除染を前記開口端部（１４ｃ）から軸方向奥方向の所定幅にわたって行い、該除染後、該本体胴（１４）の外周面に対する前記切削加工機（４４）の固定部（４６）の装着位置を、内周面（１４ｂ）の除染が済んでいる位置に設定される次の切断予定位置（Ｃ３，Ｃ４，…，Ｃｎ）よりも軸方向奥側に移動し、前記外周面切削用刃物台（６６）を使用し、該切断予定位置（Ｃ３，Ｃ４，…，Ｃｎ）で該本体胴（１４）の外周面（１４ａ）に切削刃物（７２）を対面させ、前記回転部（４８）を回転させるとともに該切削刃物（７２）を該本体胴（１４）の径方向内方向に送ることにより該切削刃物（７２）で該本体胴（１４）を外側から切削して切断し、該切断後、前記固定部（４６）の装着位置はそのままで、前記内周面切削用刃物台（７４）を使用し、前記本体胴（１４）の新たな開口端部（１４ｃ’）から切削刃物（８４）を差し入れて該切削刃物（８４）を該本体胴（１４）の内周面に対面させ、前記回転部（４８）を回転させるとともに該切削刃物（８４）を該本体胴（１４）の軸方向に送ることにより、該切削刃物（８４）で該本体胴（１４）の内周面（１４ｂ）を切削して該内周面（１４ｂ）の除染を該新たな開口端部（１４ｃ’）から軸方向奥方向の所定幅にわたって行い、以後、前記固定部（４６）の移動工程、切断工程、除染工程のサイクルを適宜回数繰り返すものである。 A method for decontamination and disassembly of a cylindrical structure according to the present invention is a method for decontaminating and disassembling a heat exchanger (10) in which the inside of a cylindrical main body (14) is radioactively contaminated, wherein the main body A fixing portion (46) mounted on the outer peripheral surface (14a) so as to surround the outer peripheral surface (14a) of (14), and the main body by the power (58) supported rotatably on the fixing portion (46). A rotating part (46) rotating around the outer peripheral surface (14a) of the body (14), a tool post (66, 74) mounted on the rotating part (46), and the tool post (66, 74) A cutting machine (44) having a mounted cutting blade (72, 84) is used, and the fixing part (46) of the cutting machine (44) is connected to the tube plate (16) of the main body barrel (14). ) On the back side of the heat transfer tube bundle (26), and the tool post as the tool post. A tool post for outer peripheral surface cutting that allows the cutting blade (72) to face the outer peripheral surface (14a) of the main body barrel (14) and feed the cutting blade (72) in the radially inward direction of the main body barrel (14). (66) and a cutting blade (72) on the outer peripheral surface (14a) of the main body barrel (14) at a position between the mounting position of the fixing portion (46) and the position of the tube plate (16). , The rotating portion (48) is rotated, and the cutting blade (72) is fed inwardly in the radial direction of the main body barrel (14), whereby the main body barrel (14) is moved by the cutting blade (72). After cutting from the outside, the heat transfer tube bundle (26) is extracted from the main body barrel (14) together with the tube plate (16), and after the extraction, the mounting position of the fixing portion (46) is As it is, the opening end formed by cutting the main body barrel (14) as the tool post 14c), the cutting blade (84) is inserted so that the cutting blade (84) faces the inner peripheral surface (14b) of the main body barrel (14) and the cutting blade (84) is placed on the shaft of the main body barrel (14). The cutting tool (84) is inserted by inserting the cutting tool (84) from the opening end (14c) of the main body barrel (14) using the inner peripheral surface cutting tool post (74) capable of feeding in the direction. By facing the inner peripheral surface (14b) of the main body cylinder (14), rotating the rotating portion (48) and sending the cutting blade (84) in the axial direction of the main body cylinder (14), the cutting The inner peripheral surface (14b) of the main body barrel (14) is cut with a cutter (84) to decontaminate the inner peripheral surface (14b) from the opening end (14c) over a predetermined width in the axial direction. After the decontamination, the cutting machine (44) is fixed to the outer peripheral surface of the main body barrel (14). The mounting position of the part (46) is moved further in the axial direction than the next scheduled cutting position (C3, C4,..., Cn) set at the position where the inner peripheral surface (14b) has been decontaminated. The cutting tool (72) is made to face the outer peripheral surface (14a) of the body barrel (14) at the planned cutting position (C3, C4,..., Cn) using the outer peripheral surface cutting tool post (66). The rotating body (48) is rotated and the cutting blade (72) is fed inward in the radial direction of the main body barrel (14) to cut the main body barrel (14) from the outside with the cutting blade (72). After the cutting, the mounting position of the fixing portion (46) is left as it is, the inner peripheral surface cutting tool post (74) is used, and a new open end ( 14c ′), the cutting blade (84) is inserted, and the cutting blade (84) is placed on the inner peripheral surface of the main body barrel (14). The cutting blade (84) is rotated in the axial direction of the main body cylinder (14) by rotating the rotating portion (48) and facing the inner periphery of the main body cylinder (14). The surface (14b) is cut to decontaminate the inner peripheral surface (14b) from the new open end (14c ′) over a predetermined width in the axial direction, and the movement of the fixed portion (46) is performed thereafter. The cycle of the process, the cutting process, and the decontamination process is repeated as appropriate.

前記抜き出された伝熱管束（２６）を切断して個々の伝熱管に分離し、該伝熱管ごとに外周面および内周面の除染を行うことができる。 The extracted heat transfer tube bundle (26) is cut and separated into individual heat transfer tubes, and the outer peripheral surface and the inner peripheral surface can be decontaminated for each heat transfer tube.

この発明によれば、切削加工機を共用して除染と解体を行うことができる。
According to the present invention, it is possible to perform decontamination and disassembly by sharing a cutting machine.

この発明の実施の形態を以下説明する。ここでは、原子力プラントの給水加熱器の除染および解体を行う場合について説明する。始めに、給水加熱器の構造を図２を参照して説明する。この給水加熱器１０は床１２上に横置き配置して使用されるものである。円筒状の本体胴１４の一端部には管板１６を挟んで水室胴１８が連結されている。水室胴１８の内部空間は仕切板２０で上下空間１８ａ，１８ｂに仕切られている。下側空間１８ｂは水室胴１８の下面に形成された給水入口２２に連通している。上側空間１８ａは水室胴１８の上面に形成された給水出口２４に連通している。本体胴１４内には伝熱管束２６がＵ字状に折り曲げられて収容されている。伝熱管束２６の入口側端部は管板１６を突き抜けて水室胴下側空間１８ｂに連通している。伝熱管束２６の出口側端部は管板１６を突き抜けて水室胴上側空間１８ａに連通している。本体胴１４の上面には蒸気入口２８が形成されている。本体胴１４の下面にはドレン出口３０が形成されている。本体胴１４にはこのほかに、胴体逃がし弁座３２、胴体空気抜座３４等が形成されている。本体胴１４の他端部は胴体鏡板３６で塞がれている。本体胴１４の下面には固定脚３８および車輪付脚４０，４２が取り付けられている。 Embodiments of the present invention will be described below. Here, the case where decontamination and dismantling of the feed water heater of a nuclear power plant is demonstrated. First, the structure of the feed water heater will be described with reference to FIG. The feed water heater 10 is used by being placed horizontally on the floor 12. A water chamber body 18 is connected to one end of the cylindrical body body 14 with a tube plate 16 in between. The internal space of the water chamber body 18 is partitioned into upper and lower spaces 18 a and 18 b by a partition plate 20. The lower space 18 b communicates with a water supply inlet 22 formed on the lower surface of the water chamber body 18. The upper space 18 a communicates with a water supply outlet 24 formed on the upper surface of the water chamber body 18. A heat transfer tube bundle 26 is accommodated in the main body barrel 14 by being bent in a U-shape. The inlet side end of the heat transfer tube bundle 26 penetrates through the tube plate 16 and communicates with the water chamber trunk lower space 18b. The outlet side end of the heat transfer tube bundle 26 penetrates the tube plate 16 and communicates with the water chamber trunk upper space 18a. A steam inlet 28 is formed on the upper surface of the main body cylinder 14. A drain outlet 30 is formed on the lower surface of the main body barrel 14. In addition to this, a body escape valve seat 32, a body air vent seat 34, and the like are formed in the main body body 14. The other end of the main body barrel 14 is closed with a body end plate 36. A fixed leg 38 and wheeled legs 40 and 42 are attached to the lower surface of the main body body 14.

本体胴１４の除染および解体に使用する切削加工機の一例を図３に示す。（ａ）は正面図、（ｂ）は右側面図である。この切削加工機４４は株式会社東立エンジニアリング製『カットランド』（商標）を使用したものである。『カットランド』は、特開２００３−１１７７２０（発明の名称「切断・開先加工装置」）に記載の技術を利用した装置である。すなわち、切削加工機４４は、本体胴１４の外径よりも大きい内径を有するリング状の固定部４６と回転部４８を具備する。固定部４６は水平方向の分割線５０で分割される上下２分割構造（半割構造）であり、両分割部分４６ａ，４６ｂをその外周面左右に配置されたフック５２（右側のフックのみ図３（ｂ）に図示）で相互に引っ掛けてボルト締めして相互に連結することができる。 An example of a cutting machine used for decontamination and disassembly of the main body cylinder 14 is shown in FIG. (A) is a front view, (b) is a right side view. This cutting machine 44 uses “Cutland” (trademark) manufactured by Todate Engineering Co., Ltd. “Cutland” is an apparatus using the technique described in Japanese Patent Application Laid-Open No. 2003-117720 (name of invention “cutting / groove processing apparatus”). That is, the cutting machine 44 includes a ring-shaped fixing portion 46 and a rotating portion 48 having an inner diameter larger than the outer diameter of the main body cylinder 14. The fixing portion 46 has an upper and lower divided structure (half structure) divided by a horizontal dividing line 50, and both divided portions 46a and 46b are hooks 52 arranged on the left and right outer peripheral surfaces (only the right hook is shown in FIG. 3). (B), they can be hooked together and bolted together to be connected to each other.

回転部４８も同様に２分割構造（半割構造）であり、連結具（図示せず）により相互に連結することができる。固定部４６および回転部４８を分割するときは、回転部４８の回転位置を初期位置（図３の位置）に合わせて、回転部上側分割部分４８ａを固定部上側分割部分４６ａに連結し、回転部下側分割部分４８ｂを固定部下側分割部分４６ｂに連結した状態で、分割線５０で上下に２分割する。つまり、固定部４６と回転部４８は、両上側分割部分４６ａ，４８ａが一体となり、かつ、両下側分割部分４６ｂ、４８ｂが一体となった状態で半割分割される。連結はこれと逆の手順で行うことができる。 Similarly, the rotating part 48 has a two-divided structure (half structure) and can be connected to each other by a connecting tool (not shown). When dividing the fixed part 46 and the rotating part 48, the rotating part 48 is aligned with the initial position (position in FIG. 3), and the rotating part upper divided part 48a is connected to the fixed part upper divided part 46a for rotation. In a state where the subordinate-side divided portion 48b is connected to the fixed portion lower-side divided portion 46b, it is divided into two vertically by a dividing line 50. In other words, the fixed portion 46 and the rotating portion 48 are divided into half in a state where the upper divided portions 46a and 48a are integrated and the lower divided portions 46b and 48b are integrated. The connection can be performed in the reverse procedure.

固定部４６の内周面には脚５４が周方向に等間隔に、適宜の本数（図３の例では８本）配置されている。脚５４の先端面はワーク（本体胴）１４の外周面１４ａに着座（当接）する。各脚５４は固定部４６の径方向に進退調整可能であり、この進退調整により、切削加工機４４をワーク１４の外周面１４ａに固定装着し、かつ、芯出し（切削加工機４４の中心軸をワーク１４の中心軸Ｌに一致させる調整操作）を行うことができる。切削加工機４４をワーク１４に装着するときは、半割された上側分割部分と下側分割部分をワーク１４の外周面１４ａの上側位置と下側位置にそれぞれ配置して、左右のフック５２を引っ掛け、さらにボルト締めして両分割部分を相互に連結する。これで、切削加工機４４はワーク１４に嵌められた状態となる。さらに、各脚５４の進退位置を調整することにより、切削加工機４４をワーク１４に確実に装着するとともに、芯出しを行う。 An appropriate number of legs 54 (eight in the example of FIG. 3) are arranged on the inner peripheral surface of the fixed portion 46 at equal intervals in the circumferential direction. The front end surface of the leg 54 is seated (abutted) on the outer peripheral surface 14 a of the work (main body trunk) 14. Each leg 54 can be adjusted to advance and retreat in the radial direction of the fixed portion 46, and by this advance and retreat adjustment, the cutting machine 44 is fixedly mounted on the outer peripheral surface 14 a of the workpiece 14, and centering (center axis of the cutting machine 44 is provided). Can be made to coincide with the central axis L of the workpiece 14). When the cutting machine 44 is mounted on the workpiece 14, the upper and lower divided portions that are divided are arranged at the upper and lower positions of the outer peripheral surface 14a of the workpiece 14, and the left and right hooks 52 are attached. Hook it and tighten it with bolts to connect the two parts together. As a result, the cutting machine 44 is fitted to the workpiece 14. Further, by adjusting the advance / retreat position of each leg 54, the cutting machine 44 is securely attached to the work 14 and centering is performed.

固定部４６の上側分割部分４６ａには、ギヤボックス５６を介して、回転部４８を回転駆動する動力源としてのモータ５８が装着されている。モータ５８は固定部４６の前面側または背面側（５８’）に装着することができる。モータ５８の回転はギヤボックス５６内のギヤで減速されて、回転部４８に伝達される。すなわち、回転部４８には、固定部４６内に収容された箇所で、図４に示すように外周面にギヤ６０が同軸状に形成されており、ギヤボックス５６内の最終段のギヤがこのギヤ６０に噛み合って回転部４８を回転駆動する。回転部４８の回転方向は図３（ａ）に矢印Ａで示す右回り方向が正転方向である。なお、ギヤ６０は回転部４８の前面（面板）と一体になって２分割される構造を有する。 A motor 58 serving as a power source for rotationally driving the rotating portion 48 is mounted on the upper divided portion 46 a of the fixed portion 46 via a gear box 56. The motor 58 can be mounted on the front side or the back side (58 ') of the fixed portion 46. The rotation of the motor 58 is decelerated by the gear in the gear box 56 and transmitted to the rotating unit 48. That is, the rotating portion 48 has a gear 60 coaxially formed on the outer peripheral surface thereof as shown in FIG. 4 at a place accommodated in the fixed portion 46, and the final stage gear in the gear box 56 is this The rotating portion 48 is rotated by meshing with the gear 60. As for the rotation direction of the rotation unit 48, the clockwise direction indicated by the arrow A in FIG. The gear 60 has a structure in which the gear 60 is divided into two parts integrally with the front surface (face plate) of the rotating portion 48.

回転部４８の前面（面板）の、回転角度が相互に１８０°ずれた位置には刃物台装着部６２，６４が設定されている。ワーク１４の切断を行うときは、刃物台装着部６２，６４に外周面切削用刃物台（突っ切りカンナ台）がそれぞれ装着され、相対向する２本の切削刃物（バイト）でワーク１４の外周面１４ａの切削を行う。ワーク１４の内周面１４ｂの除染を行うときは、刃物台装着部６２，６４の一方に内周面切削用刃物台（内径カンナ台）が装着され、他方にバランサーウエイトが装着される。 Tool post mounting portions 62 and 64 are set at positions where the rotation angles of the front surface (face plate) of the rotating portion 48 are shifted from each other by 180 °. When cutting the workpiece 14, the outer peripheral surface cutting tool post (cut-off cannula base) is mounted on the tool post mounting portions 62 and 64, respectively, and the outer peripheral surface of the work 14 is formed by two opposing cutting tools (bite). 14a is cut. When decontamination of the inner peripheral surface 14b of the work 14 is performed, an inner peripheral surface cutting tool post (inner diameter cannula base) is attached to one of the tool post attaching portions 62 and 64, and a balancer weight is attached to the other.

ワーク１４の切断を行うときの刃物台および切削刃物の配置を図５に示す（一方の刃物台のみ示す。）。（ａ）はワーク１４の軸Ｌの方向から見た正面図、（ｂ）はワーク１４の軸Ｌを通る水平面で切断した平面図である。なお、図５では、ワーク１４の外径は、実際の本体胴１４の外径よりも小さく示してある。刃物台６６は外周面切削用刃物台（突っ切りカンナ台）であり、ベース部６８が切削加工機４４の回転部４８の刃物台装着部６２（図３（ａ））にボルト６９で装着される。ベース部６８には径方向移動部７０がワーク１４の径方向に移動自在に取付支持されている。径方向移動部７０の先端部にはバイト７２が装着されている。バイト７２の刃先はワーク１４の外周面１４ａに対面している。図５では図示しないもう一方の刃物台装着部６４（図３（ａ））にも、同様の外周面切削用刃物台およびバイトが装着され、バイトの刃先はワーク１４の外周面１４ａに対面している。 The arrangement of the tool post and the cutting tool when the workpiece 14 is cut is shown in FIG. 5 (only one tool post is shown). (A) is the front view seen from the direction of the axis | shaft L of the workpiece | work 14, (b) is the top view cut | disconnected by the horizontal surface which passes along the axis | shaft L of the workpiece | work 14. FIG. In FIG. 5, the outer diameter of the workpiece 14 is shown smaller than the actual outer diameter of the main body cylinder 14. The turret 66 is an outer peripheral surface cutting turret (cut-off plane), and the base portion 68 is mounted on the turret mounting portion 62 (FIG. 3A) of the rotating portion 48 of the cutting machine 44 with a bolt 69. . A radial direction moving portion 70 is attached to and supported by the base portion 68 so as to be movable in the radial direction of the workpiece 14. A cutting tool 72 is attached to the tip of the radial direction moving part 70. The cutting edge of the cutting tool 72 faces the outer peripheral surface 14 a of the workpiece 14. The other tool post mounting part 64 (FIG. 3A) (not shown in FIG. 5) is also provided with the same outer peripheral surface cutting tool post and cutting tool, and the cutting edge of the tool faces the outer peripheral surface 14a of the workpiece 14. ing.

この状態で回転部４８を正転方向（図５（ａ）の矢印Ａ方向）に回転させると、２本のバイト７２でワーク１４の外周面１４ａを切削することができる。切削の進行に同期して径方向移動部７０をワーク１４の径方向内方向（図５の矢印Ｂ方向）に順次送り込むことにより、切削を連続して行うことができ、最終的にワークを輪切り状態に切断することができる。なお、外周面切削用刃物台６６として『カットランド』に付属の突っ切りカンナ台を使用すれば、回転部４８の回転をギヤで減速し送りネジに伝達して径方向移動部７０を径方向内方向に自動送りして、切削を自動進行させてワーク１４を切断することができる。この自動送り機構の詳細については、前述した特開２００３−１１７７２０号公報を参照されたい。 In this state, when the rotating portion 48 is rotated in the forward rotation direction (the direction of arrow A in FIG. 5A), the outer peripheral surface 14a of the workpiece 14 can be cut with the two cutting tools 72. By sequentially feeding the radially moving portion 70 in the radially inward direction of the workpiece 14 (in the direction of arrow B in FIG. 5) in synchronization with the progress of the cutting, the cutting can be performed continuously, and finally the workpiece is cut into circles. Can be cut into a state. If the cut-off cannula attached to “Cutland” is used as the outer peripheral surface cutting tool post 66, the rotation of the rotating part 48 is decelerated by the gear and transmitted to the feed screw so that the radially moving part 70 is moved in the radial direction. The workpiece 14 can be cut by automatically feeding in the direction to automatically advance the cutting. For details of the automatic feeding mechanism, refer to the aforementioned Japanese Patent Application Laid-Open No. 2003-117720.

ワーク１４の内周面１４ｂの除染を行うときの刃物台および切削刃物の配置を図６に示す。（ａ）はワーク１４の軸Ｌの方向から見た正面図、（ｂ）はワーク１４の軸Ｌを通る水平面で切断した平面図である。なお、図６では、ワーク１４の外径は、実際の本体胴１４の外径よりも小さく示してある。刃物台７４は内周面切削用刃物台（内径カンナ台）であり、ベース部７６が切削加工機４４の回転部４８の刃物台装着部６２（または６４。図３（ａ））にボルト７８で装着される。ベース部７６には径方向移動部８０がワーク１４の径方向に移動自在に取付支持されている。径方向移動部８０には軸方向移動部８２がワーク１４の軸方向（ワーク１４の中心軸Ｌに平行な方向）に移動自在に取付支持されている。軸方向移動部８２の先端部にはバイト８４が装着されている。バイト８４の刃先はワーク１４の内周面１４ｂに対面している。 FIG. 6 shows the arrangement of the tool post and the cutting tool when the inner peripheral surface 14b of the work 14 is decontaminated. (A) is the front view seen from the direction of the axis | shaft L of the workpiece | work 14, (b) is the top view cut | disconnected by the horizontal surface which passes along the axis | shaft L of the workpiece | work 14. FIG. In FIG. 6, the outer diameter of the workpiece 14 is shown smaller than the actual outer diameter of the main body cylinder 14. The turret 74 is an inner peripheral surface cutting turret (inner diameter cannula base), and the base 76 is a turret mounting portion 62 (or 64) of the rotating portion 48 of the cutting machine 44. It is installed with. A radial direction moving portion 80 is attached to and supported by the base portion 76 so as to be movable in the radial direction of the workpiece 14. An axially moving portion 82 is mounted and supported on the radially moving portion 80 so as to be movable in the axial direction of the workpiece 14 (direction parallel to the central axis L of the workpiece 14). A cutting tool 84 is attached to the tip of the axially moving portion 82. The cutting edge of the cutting tool 84 faces the inner peripheral surface 14 b of the work 14.

この状態で回転部４８を正転方向（図６（ａ）の矢印Ａ方向）に回転させると、バイト８４でワーク１４の内周面１４ｂを切削することができる。回転部４８の回転に同期して軸方向移動部８２をワーク１４の軸方向奥方向（図６（ｂ）の矢印Ｃ方向）に向けて順次送り込む（切削に隙間が生じない速度で送り込む）ことにより、切削を連続して行うことができる。このようにして、内周面１４ｂに付着した放射性物質を切削屑とともに全面的に除去することができる。内周面切削用刃物台７４の装着位置を移動せずに切削できる軸方向長さ（切削幅すなわち除染幅）は軸方向移動部８２の長さにより設定することができ、例えばワーク１４の開口端部１４ｃから１ｍ位奥までの長さに設定することができる。なお、内周面切削用刃物台７４として『カットランド』に付属の内径カンナ台を使用すれば、回転部４８の回転をギヤで減速して送りネジに伝達して軸方向移動部８２を軸方向奥方向に自動送りして、切削を自動進行させることができる。また、径方向（図６の矢印Ｄ方向）の刃先調整（切削深さの調整）は、『カットランド』に付属の内径カンナ台の場合、径方向移動部８０の径方向位置を手動操作で調整することにより行うことができる。 When the rotating part 48 is rotated in the normal rotation direction (the direction of arrow A in FIG. 6A) in this state, the inner peripheral surface 14b of the workpiece 14 can be cut with the cutting tool 84. Synchronously with the rotation of the rotating part 48, the axially moving part 82 is sequentially sent in the axially back direction of the workpiece 14 (in the direction of arrow C in FIG. 6B) (feeding at a speed that does not cause a gap in cutting). Thus, cutting can be performed continuously. In this way, the radioactive substance attached to the inner peripheral surface 14b can be removed entirely along with the cutting waste. The axial length (cutting width, that is, decontamination width) that can be cut without moving the mounting position of the inner peripheral surface cutting tool post 74 can be set by the length of the axial movement portion 82, for example, The length from the opening end 14c to the depth of about 1 m can be set. If the inner diameter cutter table attached to “Cutland” is used as the inner peripheral surface cutting tool post 74, the rotation of the rotating portion 48 is reduced by the gear and transmitted to the feed screw, so that the axial direction moving portion 82 is pivoted. Cutting can be automatically advanced by automatically feeding in the back direction. Further, the blade edge adjustment (adjustment of the cutting depth) in the radial direction (direction of arrow D in FIG. 6) is performed by manually operating the radial position of the radial moving portion 80 in the case of the inner diameter canter stand attached to “Cut Land”. This can be done by adjusting.

ここで、以上説明した図３〜図６の切削加工機４４を使用して図２の給水加熱器１０の除染および解体を行う方法を説明する。図１および図７〜図１０を参照して除染および解体作業の手順を説明する。この作業では、最初に切削加工機４４を使用して水室胴１８の切断を行う（図１のステップＳ１）。すなわち、図７の工程（１）に示すように、切削加工機４４を管板１６付近に装着し、外周面切削用刃物台６６（図５）を使用して、バイト７２を切断予定位置Ｃ１（管板１６よりも水室胴寄りの位置）の外周面１４ａに対面させる。この状態で切削加工機４４の回転部４８を回転させ、かつ、バイト７２を給水加熱器１０の径方向に順次送り込むことにより切断予定位置Ｃ１を全周にわたり順次切削し、水室胴１８を切断する。 Here, a method of performing decontamination and disassembly of the feed water heater 10 of FIG. 2 using the cutting machine 44 of FIGS. 3 to 6 described above will be described. The procedure of decontamination and dismantling work will be described with reference to FIG. 1 and FIGS. In this operation, the water chamber body 18 is first cut using the cutting machine 44 (step S1 in FIG. 1). That is, as shown in step (1) in FIG. 7, the cutting machine 44 is mounted in the vicinity of the tube plate 16, and the cutting tool C for cutting the cutting edge 72 is cut using the outer peripheral surface cutting tool post 66 (FIG. 5). It faces the outer peripheral surface 14a (position closer to the body of the water chamber than the tube plate 16). In this state, the rotating portion 48 of the cutting machine 44 is rotated, and the cutting tool C1 is sequentially cut over the entire circumference by sequentially feeding the cutting tool 72 in the radial direction of the feed water heater 10, thereby cutting the water chamber body 18. To do.

水室胴１８を切断したら、図７の工程（２）に示すように、切削加工機４４を、軸方向奥方向（管板１６よりも奥方向でかつ次の切断予定位置Ｃ２よりも奥方向。なお、「奥方向」とは、図７、図８では左方向を指す。）の本体胴１４の位置に移動して装着し直し、同様に外周面切削用刃物台６６を使用して、バイト７２を切断予定位置Ｃ２に対面させる。この状態で切削加工機４４の回転部４８を回転させ、かつ、バイト７２を給水加熱器１０の径方向に順次送り込むことにより切断予定位置Ｃ２を全周にわたり順次切削し、その位置Ｃ２で本体胴１４を切断する（図１のステップＳ２）。なお、本体胴部分１４−１が切断に伴い脱落しないように、本体胴部分１４−１を適宜の支持台８６に固定支持して切断を行う。 When the water chamber barrel 18 is cut, as shown in step (2) of FIG. 7, the cutting machine 44 is moved in the axial direction in the back direction (in the back direction from the tube sheet 16 and in the back direction from the next scheduled cutting position C2). ("Back direction" refers to the left direction in Figs. 7 and 8) and moved to the position of the main body cylinder 14 and reattached, and similarly using the outer peripheral surface cutting tool post 66, The cutting tool 72 is made to face the scheduled cutting position C2. In this state, the rotating portion 48 of the cutting machine 44 is rotated and the cutting tool 72 is sequentially fed in the radial direction of the feed water heater 10 to sequentially cut the planned cutting position C2 over the entire circumference. 14 is cut (step S2 in FIG. 1). Note that the main body barrel portion 14-1 is fixed and supported on an appropriate support base 86 so that the main body barrel portion 14-1 does not fall off during cutting.

本体胴１４−１を切断したら、図７の工程（３）に示すように、本体胴１４の残りの部分を、車輪付脚４０，４２で床１２上を転がして、切断された本体胴部分１４−１から引き離す方向に移動させる。これにより管板１６および切断された本体胴部分１４−１と一体に繋がっている伝熱管束２６が本体胴１４から抜き出される（図１のステップＳ３） When the main body cylinder 14-1 is cut, as shown in step (3) of FIG. 7, the remaining part of the main body cylinder 14 is rolled on the floor 12 with the legs 40 and 42 with wheels, and the main body cylinder portion is cut. It is moved in the direction away from 14-1. As a result, the heat transfer tube bundle 26 integrally connected to the tube plate 16 and the cut main body cylinder portion 14-1 is extracted from the main body cylinder 14 (step S3 in FIG. 1).

続いて、切削加工機４４の装着位置はそのままで、刃物台を内周面切削用刃物台７４（図６）に交換して、本体胴１４の内周面１４ｂの切削を行う。すなわち、図８の工程（４）に示すように、バイト８４を本体胴１４の開口端部１４ｃに位置決めして、本体胴１４の内周面１４ｂに対面させる。この状態で切削加工機４４の回転部４８を回転させ、かつ、バイト８４を本体胴１４の軸方向に順次送り込むことにより、次の切断予定位置Ｃ３まで（あるいは切断予定位置Ｃ３よりも少し奥側の位置まで）の所定幅（例えば１ｍ）にわたり、内周面１４ｂの全周を全面にわたり切削する。このようにして、次の切断予定位置Ｃ３まで本体胴部分１４−２の内周面１４ｂ全面の除染が行われる（図１のステップＳ４）。 Subsequently, while the mounting position of the cutting machine 44 remains unchanged, the tool post is replaced with an inner peripheral surface cutting tool post 74 (FIG. 6), and the inner peripheral surface 14b of the main body barrel 14 is cut. That is, as shown in step (4) of FIG. 8, the cutting tool 84 is positioned at the opening end portion 14 c of the main body cylinder 14 so as to face the inner peripheral surface 14 b of the main body cylinder 14. In this state, the rotating portion 48 of the cutting machine 44 is rotated and the cutting tool 84 is sequentially fed in the axial direction of the main body cylinder 14 until the next scheduled cutting position C3 (or slightly behind the planned cutting position C3). The entire circumference of the inner circumferential surface 14b is cut over the entire surface over a predetermined width (for example, 1 m). In this manner, the entire inner peripheral surface 14b of the main body barrel portion 14-2 is decontaminated up to the next scheduled cutting position C3 (step S4 in FIG. 1).

さらに、刃物台を外周面切削用刃物台６６に交換して、図８の工程（５）に示すように、切削加工機４４を次の切断予定位置Ｃ３よりも奥側の本体胴１４の位置に移動して装着し直し（図１のステップＳ５）、バイト７２を切断予定位置Ｃ３に対面させる。この状態で切削加工機４４の回転部４８を回転させ、かつ、バイト７２を本体胴１４の径方向に順次送り込むことにより切断予定位置Ｃ３を全周にわたり順次切削し、その位置Ｃ３で本体胴１４を切断する（図１のステップＳ６）。なお、本体胴１４が切断に伴い脱落しないように、本体胴１４を適宜の間隔で支持台８８に固定支持して切断を行う。 Further, the tool post is replaced with the outer peripheral surface cutting tool post 66, and as shown in step (5) of FIG. 8, the cutting machine 44 is moved to the position of the main body cylinder 14 on the back side from the next scheduled cutting position C3. Is moved and reattached (step S5 in FIG. 1), and the cutting tool 72 faces the scheduled cutting position C3. In this state, the rotating portion 48 of the cutting machine 44 is rotated and the cutting tool 72 is sequentially fed in the radial direction of the main body cylinder 14 to sequentially cut the planned cutting position C3 over the entire circumference, and at the position C3, the main body cylinder 14 is cut. Is cut (step S6 in FIG. 1). Note that the main body cylinder 14 is fixed and supported on the support base 88 at an appropriate interval so that the main body cylinder 14 does not fall off during cutting.

続いて、切削加工機４４の装着位置はそのままで、刃物台を内周面切削用刃物台７４に交換して、本体胴１４の内周面１４ｂの切削を行う。すなわち、図８の工程（６）に示すように、バイト８４を本体胴１４の新たな開口端部１４ｃ’に位置決めして、本体胴１４の内周面１４ｂに対面させる。この状態で切削加工機４４の回転部４８を回転させ、かつ、バイト８４を本体胴１４の軸方向に順次送り込むことにより、次の切断予定位置Ｃ４まで（あるいは切断予定位置Ｃ４よりも少し奥側の位置まで）の所定幅（例えば１ｍ）にわたり、内周面１４ｂの全周を全面にわたり切削する。このようにして、次の切断予定位置Ｃ４まで本体胴部分１４−３の内周面１４ｂ全面の除染が行われる（図１のステップＳ４）。 Subsequently, while the mounting position of the cutting machine 44 is kept as it is, the tool post is replaced with the inner peripheral surface cutting tool post 74 and the inner peripheral surface 14b of the main body cylinder 14 is cut. That is, as shown in step (6) of FIG. 8, the cutting tool 84 is positioned at the new opening end portion 14 c ′ of the main body cylinder 14 and is made to face the inner peripheral surface 14 b of the main body cylinder 14. In this state, the rotating portion 48 of the cutting machine 44 is rotated and the cutting tool 84 is sequentially fed in the axial direction of the main body cylinder 14 until the next scheduled cutting position C4 (or slightly behind the planned cutting position C4). The entire circumference of the inner circumferential surface 14b is cut over the entire surface over a predetermined width (for example, 1 m). In this manner, the entire inner peripheral surface 14b of the main body barrel portion 14-3 is decontaminated up to the next scheduled cutting position C4 (step S4 in FIG. 1).

以後、切削加工機４４の移動（図１のステップＳ５）、本体胴１４の切断（同ステップＳ６）、本体胴１４の内周面１４ｂ全面の除染（同ステップＳ４）を繰り返し、本体胴１４を除染しながら各切断予定位置Ｃ４，Ｃ５，…，Ｃｎで本体胴部分１４−３，１４−４，…，１４−ｎに順次切断する。切断最終予定位置Ｃｎの切断を完了したら（図１のステップＳ７）、胴体鏡板３６（１４−ｎ）および水室胴１８を適宜の方法で除染する（図１のステップＳ８）。除染および解体された水室胴１８、本体胴１４、胴体鏡板３６は再資源化される（図１のステップＳ９）。切削屑は放射性廃棄物として廃棄される。なお、本体胴１４に設けられている蒸気入口２８、ドレン出口３０、胴体逃がし弁座３２、胴体空気抜座３４等の内周面は別途適宜の方法により除染する。 Thereafter, the movement of the cutting machine 44 (step S5 in FIG. 1), cutting of the main body cylinder 14 (step S6), and decontamination of the entire inner peripheral surface 14b of the main body cylinder 14 (step S4) are repeated. .., Cn are sequentially cut into main body barrel portions 14-3, 14-4,..., 14-n. When the cutting at the final cutting position Cn is completed (step S7 in FIG. 1), the body endplate 36 (14-n) and the water chamber body 18 are decontaminated by an appropriate method (step S8 in FIG. 1). The decontaminated and disassembled water chamber barrel 18, main body barrel 14, and body endplate 36 are recycled (step S9 in FIG. 1). Cutting waste is discarded as radioactive waste. The inner peripheral surfaces of the steam inlet 28, the drain outlet 30, the fuselage relief valve seat 32, the fuselage air vent seat 34, and the like provided in the main body barrel 14 are separately decontaminated by an appropriate method.

本体胴１４から抜き出された伝熱管束２６の除染解体方法について説明する。本体部１４から抜き出された伝熱管束２６は、図９に示すように、管板１６および切断された本体胴部分１４−１と一体に繋がっている。そこで、バンドソーやワイヤソー等を使用して、伝熱管束２６を本体胴１４−１に近い位置Ｐ１とＵ字状に折り曲げられた部分に近い位置Ｐ２で切断して、個々の伝熱管に分離する（図１のステップＳ１０）。次いで、個々の伝熱管を、例えば回転している筒状のブラシ中に投入して外周面をブラシがけして、外周面に付着している放射性物質を掻き落として除染する（同ステップＳ１１）。さらに、個々の伝熱管の開口内に、回転しているブラシを挿入するすることにより内周面をブラシがけして、内周面に付着している放射性物質を掻き落として除染する（同ステップＳ１２）。除染を終了したら、各伝熱管を半割に切断し（同ステップＳ１３）、さらに図１０に示すように短いチップ２６ａに切断し（同ステップＳ１４）、再資源化する（同ステップＳ１５）。ブラシがけで掻き落とされた切削屑は放射性廃棄物として廃棄される。なお、各伝熱管のＵ字状に折り曲げられた部分についても、外周面および内周面をブラシがけして除染し、半割切断およびチップ化して再資源化する。また、残された管板１６および本体胴部分１４−１についても適宜の方法により除染し再資源化する。 A method for decontamination and disassembly of the heat transfer tube bundle 26 extracted from the main body cylinder 14 will be described. As shown in FIG. 9, the heat transfer tube bundle 26 extracted from the main body portion 14 is integrally connected to the tube plate 16 and the cut main body barrel portion 14-1. Therefore, using a band saw, a wire saw, or the like, the heat transfer tube bundle 26 is cut at a position P1 close to the main body cylinder 14-1 and a position P2 close to the portion bent in the U shape, and separated into individual heat transfer tubes. (Step S10 in FIG. 1). Next, the individual heat transfer tubes are put into, for example, a rotating cylindrical brush, the outer peripheral surface is brushed, and the radioactive material adhering to the outer peripheral surface is scraped to decontaminate (step S11). ). Furthermore, by inserting a rotating brush into the opening of each heat transfer tube, the inner peripheral surface is brushed and the radioactive material adhering to the inner peripheral surface is scraped off for decontamination (same as above). Step S12). When the decontamination is completed, each heat transfer tube is cut into halves (step S13), and further cut into short chips 26a as shown in FIG. 10 (step S14) and recycled (step S15). The cutting scraps scraped off with the brush are discarded as radioactive waste. In addition, also about the part bent by the U shape of each heat exchanger tube, the outer peripheral surface and an inner peripheral surface are decontaminated by brushing, and it cuts into half and cuts into chips and recycles. Further, the remaining tube plate 16 and main body barrel portion 14-1 are also decontaminated and recycled by an appropriate method.

なお、前記実施の形態では本体胴１４の開口端部側から奥側に向けて内周面１４ｂの切削を行うようにしたが、逆に奥側から開口端部側に向けて内周面１４ｂの切削を行うこともできる。また、前記実施の形態では、回転部４８を連続して回転しながら軸方向移動部８２をワーク１４の軸方向奥方向に向けて順次送り込むことにより内周面１４ｂの切削を行うようにしたが（つまり螺旋状に切削するようにしたが）、これに代えて、回転部４８の回転を止めて軸方向移動部８２をワーク１４の開口端部１４ｃから軸方向奥方向に向けて所定距離移送して切削し、次いで回転部４８を微少量回転させて止めて、そこで再び軸方向移動部８２をワーク１４の開口端部１４ｃから軸方向奥方向に向けて所定距離移送して切削し、以後この動作を回転部４８が１周するまで繰り返すことにより内周面１４ｂの切削を行う（つまり軸方向の切削を内周面１４ｂの全周にわたり繰り返し行う）こともできる。また、前記実施の形態では、外周面切削用刃物台６６は、バイト７２をワーク１４の径方向のみに送るようにしたが、軸方向にも移動できるようにして、バイト７２の厚みよりも広い溝幅で切削して切断を行うこともできる。また、前記実施の形態では、内周面１４ｂの切削を行ってから該切削した部分の切断を行うようにしたが、切断を行ってから該切断した部分の内周面１４ｂの切削を行うこともできる。 In the above embodiment, the inner peripheral surface 14b is cut from the opening end side to the back side of the main body barrel 14, but conversely the inner peripheral surface 14b from the back side to the opening end side. Can also be cut. In the above-described embodiment, the inner peripheral surface 14b is cut by sequentially feeding the axially moving portion 82 toward the back in the axial direction of the workpiece 14 while continuously rotating the rotating portion 48. Instead of this, the rotation of the rotating part 48 is stopped and the axially moving part 82 is transferred from the opening end part 14c of the work 14 in the axially rearward direction by a predetermined distance. Then, the rotary part 48 is rotated by a small amount and stopped. Then, the axially moving part 82 is again transferred from the opening end part 14c of the work 14 in the axially back direction by a predetermined distance and then cut. It is also possible to cut the inner peripheral surface 14b by repeating this operation until the rotating portion 48 makes one round (that is, to repeat axial cutting over the entire circumference of the inner peripheral surface 14b). In the above embodiment, the outer peripheral surface cutting tool post 66 feeds the cutting tool 72 only in the radial direction of the workpiece 14, but it can move in the axial direction and is wider than the thickness of the cutting tool 72. Cutting can also be performed by cutting with the groove width. In the embodiment, the cut portion is cut after the inner peripheral surface 14b is cut, but the inner peripheral surface 14b of the cut portion is cut after the cut. You can also.

前記実施の形態では、原子力プラントの給水加熱器の除染および解体を行う場合について説明したが、これに限らず、原子力プラントの蒸気発生器、その他の内周面が放射能汚染された熱交換器、配管等の円筒状構造物についてこの発明の方法により除染および解体を行うことができる。 In the above-described embodiment, the case of performing decontamination and dismantling of the feed water heater of the nuclear power plant has been described. However, the present invention is not limited thereto, and heat exchange in which the nuclear power plant steam generator and other inner peripheral surfaces are radioactively contaminated is described. Decontamination and disassembly can be performed on cylindrical structures such as vessels and piping by the method of the present invention.

図３〜図６の切削加工機４４を使用して図２の給水加熱器１０の除染および解体を行う手順を示すフローチャートである。It is a flowchart which shows the procedure which performs the decontamination and dismantling of the feed water heater 10 of FIG. 2 using the cutting machine 44 of FIGS. 原子力プラントの給水加熱器の構造を示す縦断面側面図である。It is a longitudinal cross-sectional side view which shows the structure of the feed water heater of a nuclear power plant. 図２の給水加熱器の本体胴１４の除染および解体に使用する切削加工機の一例を示す正面図および右側面図である。It is the front view and right view which show an example of the cutting machine used for decontamination and the dismantling of the main body cylinder 14 of the feed water heater of FIG. 図３の切削加工機の回転部４８に同軸状に形成されたギヤを示す斜視図である。It is a perspective view which shows the gear formed coaxially in the rotation part 48 of the cutting machine of FIG. 図３の切削加工機を使用して図２の給水加熱器の本体胴１４の切断を行うときの刃物台および切削刃物の配置を示す図で、（ａ）は軸方向から見た正面図、（ｂ）は軸を通る水平面で切断した平面図である。It is a figure which shows arrangement | positioning of the tool post and the cutting blade when cutting the main body cylinder 14 of the feed water heater of FIG. 2 using the cutting machine of FIG. 3, (a) is a front view seen from the axial direction, (B) is the top view cut | disconnected by the horizontal surface which passes along an axis | shaft. 図３の切削加工機を使用して図２の給水加熱器の本体胴１４の除染を行うときの刃物台および切削刃物の配置を示す図で、（ａ）は軸方向から見た正面図、（ｂ）は軸を通る水平面で切断した平面図である。It is a figure which shows arrangement | positioning of the tool post and the cutting blade when decontaminating the main body cylinder 14 of the feed water heater of FIG. 2 using the cutting machine of FIG. 3, (a) is the front view seen from the axial direction (B) is the top view cut | disconnected by the horizontal surface which passes along an axis | shaft. 図１の手順の主要な工程の説明図である。It is explanatory drawing of the main processes of the procedure of FIG. 図７の続きの工程を示す説明図である。FIG. 8 is an explanatory diagram showing a continuation process of FIG. 7. 伝熱管束２６の切断位置の一例を示す図である。It is a figure which shows an example of the cutting position of the heat exchanger tube bundle. 伝熱管の半割切断されたチップを示す斜視図である。It is a perspective view which shows the chip | tip by which the heat exchanger tube was cut | disconnected by half.

Explanation of symbols

１０…給水加熱器（熱交換器）、１４…本体胴（円筒状構造物）、１４−１，１４−２，・・・，１４−ｎ…切断されたまたは切断される本体胴部分、１４ａ…外周面、１４ｂ…内周面、１４ｃ…円筒状構造物の開口端部、１４ｃ’…円筒状構造物の新たな開口端部、１６…管板、２６…伝熱管束、４４…切削加工機、４６…固定部、４８…回転部、５８…モータ（動力）、６６…外周面切削用刃物台、７２，８４…バイト（切削刃物）、７４…内周面切削用刃物台、Ｃ１，Ｃ２，・・・，Ｃｎ…切断予定位置、Ｌ…円筒状構造物の中心軸。 DESCRIPTION OF SYMBOLS 10 ... Feed water heater (heat exchanger), 14 ... Main body trunk | drum (cylindrical structure), 14-1, 14-2, ..., 14-n ... Main body trunk part cut | disconnected or cut | disconnected, 14a ... outer peripheral surface, 14b ... inner peripheral surface, 14c ... open end of cylindrical structure, 14c '... new open end of cylindrical structure, 16 ... tube plate, 26 ... heat transfer tube bundle, 44 ... cutting , 46 ... fixed part, 48 ... rotating part, 58 ... motor (power), 66 ... outer peripheral surface cutting tool post, 72, 84 ... cutting tool (cutting tool), 74 ... inner peripheral surface cutting tool post, C1, C2,..., Cn: scheduled cutting position, L: central axis of the cylindrical structure.

Claims

A fixed portion mounted on the outer peripheral surface so that the inner peripheral surface surrounds the outer peripheral surface of the radioactively contaminated cylindrical structure, and an outer periphery of the cylindrical structure that is rotatably supported by the fixed portion and driven by power Using a cutting machine comprising a rotating part that rotates around a surface, a tool post mounted on the rotating part, and a cutting tool mounted on the tool post,
A cutting blade is inserted from the opening end of the cylindrical structure so that the cutting blade faces the inner peripheral surface of the cylindrical structure, the rotating portion is rotated, and the cutting blade is moved to the axis of the cylindrical structure. Cutting the inner peripheral surface of the cylindrical structure with the cutting blade by sending in the direction to decontaminate the inner peripheral surface,
A cutting blade is made to face the outer peripheral surface of the cylindrical structure, the rotating portion is rotated, and the cutting blade is fed inward in the radial direction of the cylindrical structure so that the cylindrical structure is moved with the cutting blade. A method for decontamination and disassembly of a cylindrical structure in which the cylindrical structure is disassembled by cutting and cutting from the outside ,
When performing decontamination of the inner peripheral surface, as the tool post, a cutting tool is inserted from the opening end of the cylindrical structure so that the cutting tool faces the inner peripheral surface of the cylindrical structure, and Using an inner peripheral surface cutting tool post capable of sending a cutting tool in the axial direction of the cylindrical structure,
When the dismantling is performed, as the tool post, the cutting tool is used for cutting an outer peripheral surface, which allows the cutting tool to face the outer peripheral surface of the cylindrical structure and feed the cutting tool in the radially inward direction of the cylindrical structure. Use the tool post,
Performing the decontamination over a predetermined width in the axial direction from the opening end of the cylindrical structure on the inner peripheral surface of the cylindrical structure,
After the decontamination, the mounting position of the fixed portion of the cutting machine with respect to the outer peripheral surface of the cylindrical structure is set to the back side in the axial direction from the planned cutting position set at the position where the inner peripheral surface has been decontaminated. To perform the cutting at the planned cutting position,
After the cutting, the removal position of the fixed portion of the cutting machine is left as it is over the predetermined width in the axial direction from the new opening end of the cylindrical structure on the inner peripheral surface of the cylindrical structure. A method for decontamination and disassembly of a cylindrical structure for dyeing.

The decontamination step, the moving step of the fixed part, decontamination and dismantling method according to claim 1 cylindrical structure according to repeat as appropriate number of cycles of the cutting process.

A method for decontaminating and dismantling a heat exchanger in which the inside of a cylindrical main body is radioactively contaminated,
A fixed portion mounted on the outer peripheral surface so as to surround the outer peripheral surface of the main body barrel; a rotating portion that is rotatably supported by the fixed portion and rotates around the outer peripheral surface of the main body barrel by power; and the rotation Using a cutting machine equipped with a tool post mounted on the part and a cutting tool mounted on the tool post,
Attach the fixed part of the cutting machine to the position on the side of the main body barrel, which is behind the tube sheet, on which the heat transfer tube bundle is disposed,
Use of an outer peripheral surface cutting tool post capable of causing the cutting tool to face the outer peripheral surface of the main body cylinder and feeding the cutting tool radially inward of the main body cylinder as the tool post, and the mounting position of the fixed portion And a position of the tube sheet between the cutting edge and the outer peripheral surface of the main body cylinder, the cutting blade is rotated, and the rotating portion is rotated and the cutting blade is sent inward in the radial direction of the main body cylinder. Cutting the main body cylinder from the outside with a cutting blade and cutting it,
After the cutting, the heat transfer tube bundle is extracted from the main body body together with the tube plate,
After the extraction, the mounting position of the fixed part is left as it is, and the cutting tool is inserted from the opening end formed by cutting the main body cylinder as the tool post so that the cutting tool faces the inner peripheral surface of the main body cylinder. And using an inner peripheral surface cutting turret capable of feeding the cutting tool in the axial direction of the main body cylinder, inserting the cutting tool from the opening end of the main body cylinder, and inserting the cutting tool into the inner side of the main body cylinder. Decontamination of the inner peripheral surface by cutting the inner peripheral surface of the main body cylinder with the cutting blade by causing the cutting blade to face the peripheral surface, rotating the rotating portion and sending the cutting blade in the axial direction of the main body cylinder Over a predetermined width in the axial direction from the opening end,
After the decontamination, the mounting position of the fixed portion of the cutting machine with respect to the outer peripheral surface of the main body cylinder is set to the back side in the axial direction from the next scheduled cutting position set to the position where the inner peripheral surface has been decontaminated And using the outer peripheral surface cutting turret, causing the cutting tool to face the outer peripheral surface of the main body barrel at the planned cutting position, rotating the rotating portion and causing the cutting tool to move in the radial direction of the main body cylinder. Cutting the main body cylinder from the outside with the cutting blade by sending it inwardly,
After the cutting, the mounting position of the fixed part is kept as it is, and the cutting tool for cutting the inner peripheral surface is used, and the cutting tool is inserted from a new opening end of the main body cylinder so that the cutting tool is inserted into the main body cylinder. Decontamination of the inner peripheral surface by cutting the inner peripheral surface of the main body cylinder with the cutting blade by causing the cutting blade to face the peripheral surface, rotating the rotating portion and sending the cutting blade in the axial direction of the main body cylinder Over a predetermined width in the axial depth direction from the new opening end,
Thereafter, a method for decontamination and dismantling of a cylindrical structure in which a cycle of the fixing part moving step, cutting step, and decontamination step is repeated as appropriate.

4. The decontamination and dismantling of the cylindrical structure according to claim 3, wherein the extracted heat transfer tube bundle is cut and separated into individual heat transfer tubes, and the outer peripheral surface and the inner peripheral surface are decontaminated for each heat transfer tube. Method.