JP4991213B2 - Reactor control rod - Google Patents

Reactor control rod Download PDF

Info

Publication number
JP4991213B2
JP4991213B2 JP2006233080A JP2006233080A JP4991213B2 JP 4991213 B2 JP4991213 B2 JP 4991213B2 JP 2006233080 A JP2006233080 A JP 2006233080A JP 2006233080 A JP2006233080 A JP 2006233080A JP 4991213 B2 JP4991213 B2 JP 4991213B2
Authority
JP
Japan
Prior art keywords
control rod
sheath
neutron absorbing
hafnium
integrated
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2006233080A
Other languages
Japanese (ja)
Other versions
JP2008058053A (en
Inventor
精 植田
庄一 渡辺
研一 吉岡
偉司 三橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to JP2006233080A priority Critical patent/JP4991213B2/en
Publication of JP2008058053A publication Critical patent/JP2008058053A/en
Application granted granted Critical
Publication of JP4991213B2 publication Critical patent/JP4991213B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Landscapes

  • Monitoring And Testing Of Nuclear Reactors (AREA)

Description

本発明は、ハフニウム（Ｈｆ）の金属又はその合金を中性子吸収材とする原子炉用制御棒に関する。   The present invention relates to a nuclear reactor control rod using a hafnium (Hf) metal or an alloy thereof as a neutron absorber.

沸騰水型原子炉（ＢＷＲ）の制御棒は、縦長の４枚の翼（ウイング）を断面十字型に組み立てて構成される。炉心は、断面方形に形成された４体の燃料集合体が制御棒の各ウイングを挟むように配列されて一つのセルとされ、このセルが多数配置されて構成される。このような原子炉用制御棒には、長寿命化の要請から、ハフニウムを主な中性子吸収材とする「ハフニウム制御棒」が知られている。この「ハフニウム制御棒」は、１〜２ｍｍ程度の厚さのハフニウム板を２枚、間隙をあけて対向させて一体型中性子吸収要素とし、この一体型中性子吸収要素を、各ウイングの外形を構成するステンレス鋼（ＳＵＳ）製のシース内に収納した構成である。この制御棒を炉心中で使用している状態では、ハフニウム板の上記間隙の部分に水が満たされる。この水は、両側のハフニウム板から入ってきた高速中性子を減速させ、この減速された中性子をハフニウム板に効率良く吸収させるものである。この水が高速中性子を減速して捕獲する構成であることから、上記制御棒は「ハフニウムトラップ型制御棒」と呼ばれている。   The control rod of a boiling water reactor (BWR) is constructed by assembling four vertically long blades (wings) into a cross-shaped cross section. The reactor core is configured by arranging four fuel assemblies formed in a square cross section so as to sandwich the wings of the control rods into one cell, and a large number of these cells are arranged. As such a control rod for a nuclear reactor, a “hafnium control rod” using hafnium as a main neutron absorber is known because of a demand for longer life. This "hafnium control rod" is composed of two hafnium plates with a thickness of about 1 to 2 mm, facing each other with a gap between them to form an integrated neutron absorbing element, and this integrated neutron absorbing element constitutes the outer shape of each wing In a sheath made of stainless steel (SUS). In a state where the control rod is used in the reactor core, the gap portion of the hafnium plate is filled with water. This water decelerates fast neutrons that have entered from the hafnium plates on both sides, and efficiently absorbs the decelerated neutrons into the hafnium plates. Since this water is configured to decelerate and capture fast neutrons, the control rod is called a “hafnium trap type control rod”.

このようなハフニウムトラップ型の原子炉用制御棒が特許文献１に記載され、更に、急速挿入などの衝撃に対する機械的特性を改良したものが特許文献２に、長寿命化に伴う腐食問題を改良したものが特許文献３に、それぞれ記載されている。   Such a hafnium trap type control rod for a nuclear reactor is described in Patent Document 1, and further improved mechanical characteristics against impact such as rapid insertion is improved in Patent Document 2 to improve the corrosion problem associated with extending the life. These are described in Patent Document 3, respectively.

図１３は、特許文献１にて開示され、実用化された原子炉用制御棒の概要を示し、（Ａ）は一部を切り欠いて示す斜視図、（Ｂ）は図１３(Ａ)の一ウイングを示す横断面図、（Ｃ）は図１３(Ｂ)における保持部材を示す斜視図である。図１３に示すように、この原子炉用制御棒１は、ハンドル３を含む先端構造材４、４枚の翼（ウイング）２、及び末端構造材５が中央構造材（タイロッド）６に固着されて十字型に形成される。末端構造材５には、結合部異常分離時に制御棒１が炉心から落下する際の速度を抑制する速度制限部材（Ｓｐｅｅｄ ｌｉｍｉｔｅｒ）が設けられているが、この図では省略されている。   FIG. 13: shows the outline | summary of the control rod for reactors disclosed by patent document 1 and put into practical use, (A) is a perspective view which cuts out one part, (B) is FIG. 13 (A). FIG. 14C is a cross-sectional view showing one wing, and FIG. 14C is a perspective view showing the holding member in FIG. As shown in FIG. 13, this nuclear reactor control rod 1 has a tip structural member 4 including a handle 3, four wings (wings) 2, and a terminal structural member 5 fixed to a central structural member (tie rod) 6. To form a cross. The end structural member 5 is provided with a speed limiter (Speed limiter) that suppresses the speed at which the control rod 1 drops from the core at the time of abnormal separation of the joint, but is omitted in this figure.

各ウイング２は、深いＵ字状の横断面を有するステンレス鋼（ＳＵＳ）製のシース７の内部に、中性子吸収材としての２枚のハフニウム板１０を保持部材１２でシース７と一体化した複数の一体型中性子吸収要素１４が収納されて構成される。また、シース７には規則的に通水孔９が設けられている。この通水孔９は、通常、制御棒挿抜方向（つまり原子炉用制御棒１の軸方向）と直角方向に２個ずつペアとなって、制御棒挿抜方向に規則的に配列されている。   Each wing 2 includes a plurality of stainless steel (SUS) sheaths 7 having a deep U-shaped cross section, in which two hafnium plates 10 as neutron absorbers are integrated with the sheaths 7 by holding members 12. The integrated neutron absorbing element 14 is accommodated. The sheath 7 is regularly provided with water passage holes 9. The water passage holes 9 are normally arranged in pairs in the control rod insertion / removal direction in pairs of two in the direction perpendicular to the control rod insertion / removal direction (that is, the axial direction of the reactor control rod 1).

上記ハフニウム板１０は、ハフニウムの金属、またはハフニウムをジルコニウムやチタン等の希釈材で希釈したハフニウム合金から成る。また、上記保持部材１２は駒のような形状であり、対向する２枚のハフニウム板１０の間隙を保持するスペーサ部１２Ａと、このスペーサ部１２Ａに一体成形された軸部１２Ｂとを備えて成る。   The hafnium plate 10 is made of hafnium metal or a hafnium alloy obtained by diluting hafnium with a diluent such as zirconium or titanium. The holding member 12 has a shape like a piece, and includes a spacer portion 12A that holds a gap between two opposing hafnium plates 10, and a shaft portion 12B that is integrally formed with the spacer portion 12A.

ハフニウム板１０とステンレス鋼（ＳＵＳ）製のシース７とでは熱膨張係数が大幅に異なるため、その問題を解決すべく、図１４に示すように、一体型中性子吸収要素１４は、制御棒挿抜方向に分離して複数個配列され、それぞれの一体型中性子吸収要素１４が保持部材１２によってシース７に保持されている。一体型中性子吸収要素１４の制御棒挿抜方向の配列数は、原子炉内における制御棒１の中性子被照射量に関する従来からの管理の習慣に従って偶数個とされており、図１５に代表的な例を示す。   Since the thermal expansion coefficient is significantly different between the hafnium plate 10 and the stainless steel (SUS) sheath 7, as shown in FIG. 14, the integrated neutron absorbing element 14 has a control rod insertion / removal direction. A plurality of integrated neutron absorbing elements 14 are held on the sheath 7 by the holding member 12. The number of arrangements of the integrated neutron absorbing elements 14 in the control rod insertion / extraction direction is an even number according to the conventional management practice regarding the neutron irradiation amount of the control rod 1 in the nuclear reactor, and a typical example is shown in FIG. Indicates.

図１５（Ａ）では、一体型中性子吸収要素１４は、制御棒挿抜方向に等間隔で８個配列され、各一体型中性子吸収要素１４毎に、制御棒挿入先端側から挿入末端へ向かってハフニウム板１０の厚さが順次薄くなるように構成されている。これは、原子炉用制御棒１においては、制御棒挿入先端側ほど中性子照射量が多く、この領域で反応度価値(中性子吸収能力)を高める必要があるからである。また、図１５(Ｂ)では、一体型中性子吸収要素１４は、制御棒挿抜方向に８個配列されているが、そのハフニウム板１０は、制御棒挿入先端側から２個ずつ同じ厚さで挿入末端側へ向かって薄く形成されている。原子炉用制御棒１において、挿入先端側から中性子吸収材の全長Ｌの１／２ないし６／８の領域では、通常、シース７の厚さに比べてハフニウム板１０の方が厚くなっている。図１５（Ｃ）では、一体型中性子吸収要素１４は軸方向に同じ長さで２個配列され、そのハフニウム板１０は、制御棒挿入先端側でシース７よりも厚く、挿入末端側でシース７と同程度か若干薄くなっている。   In FIG. 15A, eight integrated neutron absorbing elements 14 are arranged at equal intervals in the control rod insertion / removal direction, and for each integrated neutron absorbing element 14, hafnium is directed from the control rod insertion tip side toward the insertion end. It is comprised so that the thickness of the board 10 may become thin sequentially. This is because in the nuclear reactor control rod 1, the amount of neutron irradiation is larger toward the control rod insertion tip side, and the reactivity value (neutron absorption capability) needs to be increased in this region. In FIG. 15B, eight integrated neutron absorbing elements 14 are arranged in the control rod insertion / removal direction, but two hafnium plates 10 are inserted with the same thickness two by two from the control rod insertion tip side. It is formed thin toward the end side. In the nuclear reactor control rod 1, the hafnium plate 10 is usually thicker than the sheath 7 in the region from 1/2 to 6/8 of the total length L of the neutron absorber from the insertion tip side. . In FIG. 15C, two integrated neutron absorbing elements 14 having the same length are arranged in the axial direction, and the hafnium plate 10 is thicker than the sheath 7 at the control rod insertion tip side, and the sheath 7 at the insertion end side. It is about the same or slightly thinner.

尚、図１４は図１５（Ｂ）に相当するものの例であって、図１４(Ａ)は、図１３(Ａ)の原子炉用制御棒において前面のシースを切り欠いて示す正面図、図１４(Ｂ)は、中性子吸収材であるハフニウム板の厚さ分布及び反応度価値を示す図である。   14 is an example corresponding to FIG. 15B, and FIG. 14A is a front view of the reactor control rod of FIG. 14 (B) is a diagram showing the thickness distribution and reactivity value of a hafnium plate which is a neutron absorber.

図１６（Ａ）は、図１４（Ａ）の要部拡大正面図、図１６（Ｂ）は、図１６（Ａ）の一対のハフニウム板（一体型中性子吸収要素）を拡大して示す正面図、図１６（Ｃ）は、図１６（Ｂ）のXVI‐XVI線に沿う断面図である。前述のように、一体型中性子吸収要素１４は保持部材１２によってシース７に保持され、この保持部材１２は、スペーサ部１２Ａ及び軸部１２Ｂを備えてなる。軸部１２Ｂは、一体型中性子吸収要素１４の２枚のハフニウム板１０に形成された貫通孔１３と、シース７に形成された装着孔８に挿通され、シース７の外面から突出しないように当該外面に溶接により固着される。また、スペーサ部１２Ａは、一体型中性子吸収要素１４の２枚のハフニウム板１０間に配置されて、これらのハフニウム板１０の間隙を水ギャップ１１として保持する。この水ギャップ１１に満たされる水が、前述の如く高速中性子を減速する。   16A is an enlarged front view of the main part of FIG. 14A, and FIG. 16B is an enlarged front view of the pair of hafnium plates (integrated neutron absorbing elements) in FIG. 16A. FIG. 16C is a cross-sectional view taken along line XVI-XVI in FIG. As described above, the integrated neutron absorbing element 14 is held on the sheath 7 by the holding member 12, and the holding member 12 includes the spacer portion 12A and the shaft portion 12B. The shaft portion 12B is inserted into the through hole 13 formed in the two hafnium plates 10 of the integrated neutron absorbing element 14 and the mounting hole 8 formed in the sheath 7 so as not to protrude from the outer surface of the sheath 7. It is fixed to the outer surface by welding. The spacer portion 12 </ b> A is disposed between the two hafnium plates 10 of the integrated neutron absorbing element 14, and holds the gap between these hafnium plates 10 as the water gap 11. The water filled in the water gap 11 decelerates the fast neutrons as described above.

また、ハフニウム板１０とステンレス鋼製のシース７とは、熱膨張係数が３倍程度異なる。このため、ハフニウム板１０の貫通孔１３の直径は、保持部材１２の軸部１２Ｂの直径よりも大きく形成されて、両者間に孔間隙１６が設けられている。これにより、原子炉運転に際しての熱サイクルにおける膨張と収縮によっても、ハフニウム板１０とシース７との干渉が回避される。   Further, the hafnium plate 10 and the stainless steel sheath 7 have different thermal expansion coefficients by about three times. For this reason, the diameter of the through-hole 13 of the hafnium plate 10 is formed larger than the diameter of the shaft portion 12B of the holding member 12, and the hole gap 16 is provided between them. Thus, interference between the hafnium plate 10 and the sheath 7 can be avoided by expansion and contraction in the thermal cycle during the operation of the nuclear reactor.

図１７（Ａ）は図１３（Ａ）の原子炉用制御棒の一ウイングを拡大して示す正面図であり、図１７（Ｂ）、図１７（Ｃ）、図１７（Ｄ）は、図１７（Ａ）のXVIIＢ‐XVIIＢ線、XVIIＣ‐XVIIＣ線、XVIIＤ‐XVIIＤ線にそれぞれ沿う断面図である。保持部材１２は、図１３にも示すように、一つの一体型中性子吸収要素１４における挿入先端側と挿入末端側に一対ずつ設けられている。シース通水孔９Ａは、図１７（Ｄ）に示すように、シース７にのみ形成されたものである。また、重複通水孔９Ｂは、図１７（Ｃ）に示すように、シース７及びハフニウム板１０に同軸状態で重複して設けられたものである。これらのシース通水孔９Ａ及び重複通水孔９Ｂが、前記通水孔９を構成する。更に、シース７を中央構造材６に溶接する溶接点１５は、中央構造材６における制御挿抜方向に等間隔に設けられている。   FIG. 17A is an enlarged front view showing one wing of the nuclear reactor control rod of FIG. 13A, and FIGS. 17B, 17C, and 17D are diagrams. It is sectional drawing which follows the XVIIB-XVIIB line | wire, XVIIC-XVIIC line | wire, and XVIID-XVIID line | wire of 17 (A), respectively. As shown in FIG. 13, a pair of holding members 12 are provided on the insertion tip side and the insertion end side of one integrated neutron absorption element 14. The sheath water passage hole 9A is formed only in the sheath 7 as shown in FIG. In addition, as shown in FIG. 17C, the overlapping water passage hole 9B is provided to overlap the sheath 7 and the hafnium plate 10 in a coaxial state. These sheath water passage holes 9 </ b> A and overlapping water passage holes 9 </ b> B constitute the water passage hole 9. Furthermore, the welding points 15 for welding the sheath 7 to the central structural member 6 are provided at equal intervals in the control insertion / extraction direction of the central structural member 6.

図１８は、図１３に示す原子炉用制御棒と考え方を若干異にする設計で実用化されたハフニウムトラップ型の原子炉用制御棒の例である。この原子炉用制御棒２１では、深いＵ字状のシース７の内部に、一体型中性子吸収要素２４を構成する中性子吸収材である「平板化されたハフニウム管２０」（フラットチューブ、平管と呼ばれることがある）がウイング２の幅方向に２個、制御棒挿抜方向に２個、分離して収納されている。制御棒挿抜方向の分離位置は、おおよそ中性子吸収材の全長Ｌの１／２付近である。この種の設計では、図１８(Ｃ)に示すように、ウイング２の厚さ方向におけるハフニウム管２０の間隔は、このハフニウム管２０を構成する各ハフニウム板２０Ａ、２０Ｂが側端で曲げられて固着されているため、図１３（Ｃ）のような駒形状の保持部材１２を用いる必要はなく、この保持部材１２の軸部１２Ｂのみからなる保持部材(スティフナ)２２を用いればよい。   FIG. 18 is an example of a hafnium trap-type nuclear reactor control rod that has been put into practical use with a design slightly different from the nuclear reactor control rod shown in FIG. In this nuclear reactor control rod 21, a “flattened hafnium tube 20” (flat tube, flat tube, and so on), which is a neutron absorber constituting the integrated neutron absorbing element 24, is disposed inside the deep U-shaped sheath 7. 2) in the width direction of the wing 2 and 2 in the control rod insertion / removal direction. The separation position in the control rod insertion / extraction direction is approximately around ½ of the total length L of the neutron absorber. In this type of design, as shown in FIG. 18C, the distance between the hafnium tubes 20 in the thickness direction of the wing 2 is such that the hafnium plates 20A and 20B constituting the hafnium tube 20 are bent at the side ends. Since it is fixed, it is not necessary to use the frame-shaped holding member 12 as shown in FIG. 13C, and a holding member (stiffener) 22 consisting only of the shaft portion 12B of the holding member 12 may be used.

このスティフナ２２は、一体型中性子吸収要素２４のハフニウム管２０に形成された貫通孔２３に挿通されて、両端がシース７に固着され、このシース７の対向する間隔を保持する。この一体型中性子吸収要素２４においても、上記貫通孔２３とスティフナ２２との間には孔間隙(不図示)が設けられて、ハフニウム管２０とステンレス鋼製のシース７との熱膨張差を吸収できるようになっている。また、一体型中性子吸収要素２４は、挿入先端側では先端構造材４に、挿入末端側では末端構造材５に、それぞれの固定部２７を用いて固定される。更に、一体型中性子吸収要素２４及びシース７には、前記原子炉用制御棒１と同様な通水孔９が形成されている。このうち、符合９Ｘは、シース７とハフニウム管２０に重複して設けられた重複通水孔であり、符合９Ｘ２は、この重複通水孔９Ｘのうちのハフニウム管２０に形成されたハフニウム孔を示す。
特開昭６２−２３５５９５号公報 特開平１０−１０４３８２号公報 特開平１１−１１８９７２号公報 The stiffener 22 is inserted into a through-hole 23 formed in the hafnium tube 20 of the integrated neutron absorption element 24, and both ends are fixed to the sheath 7, and the facing distance of the sheath 7 is maintained. Also in this integrated neutron absorbing element 24, a hole gap (not shown) is provided between the through hole 23 and the stiffener 22 to absorb the difference in thermal expansion between the hafnium tube 20 and the stainless steel sheath 7. It can be done. Further, the integrated neutron absorbing element 24 is fixed to the distal end structural member 4 on the insertion distal end side and to the distal end structural member 5 on the insertion distal end side using the respective fixing portions 27. Further, the integrated neutron absorbing element 24 and the sheath 7 are formed with water holes 9 similar to the reactor control rod 1. Among these, reference numeral 9X is an overlapping water hole provided overlapping the sheath 7 and the hafnium tube 20, and reference numeral 9X2 is a hafnium hole formed in the hafnium tube 20 of the overlapping water hole 9X. Show.
JP 62-235595 A Japanese Patent Laid-Open No. 10-104382 Japanese Patent Laid-Open No. 11-118972

ところが、上述のようなハフニウムトラップ型の原子炉用制御棒１、２１にあっては、シース７等の構造材と、ハフニウムを主な中性子吸収材とする一体型中性子吸収要素１４、２４との中性子照射による照射成長、並びに運転開始から停止までの運転サイクルにおける制御棒各部位、特に上記シース７、一体型中性子吸収要素１４、２４の機械的な挙動や通水性などを考慮したとき、長寿命化に伴う健全性の確保についてさらなる改良の余地があることが判明した。   However, in the hafnium trap-type reactor control rods 1 and 21 as described above, the structural material such as the sheath 7 and the integrated neutron absorbing elements 14 and 24 having hafnium as the main neutron absorber are provided. Long life when considering the growth of neutron irradiation and the mechanical behavior and water permeability of each part of the control rod, particularly the sheath 7 and the integrated neutron absorbing elements 14 and 24 in the operation cycle from the start to the stop of operation. It has been found that there is room for further improvement in ensuring soundness due to computerization.

本発明の目的は、上述の事情を考慮してなされたものであり、健全性を確保しつつ長寿命化を実現できる原子炉用制御棒を提供することにある。   An object of the present invention is to provide a control rod for a nuclear reactor that can achieve a long life while ensuring soundness.

本発明は、横断面がＵ字状をなす長尺のシースの開口部を、中央構造材に固着して複数のウイングを構成し、このウイングの炉心挿入方向先端側に先端構造材を、挿入末端側に末端構造材をそれぞれ固着すると共に、板状のハフニウムを主な中性子吸収材とする複数の一体型中性子吸収要素を、前記シース内に当該シースの長手方向に列状に収容する原子炉用制御棒において、制御棒挿抜方向に配列された複数の前記一体型中性子吸収要素のうち、挿入先端から１／４乃至３／４の範囲で、前記中性子吸収材の厚さが前記シースの厚さよりも厚い制御棒挿入先端側に位置する一体型中性子吸収要素では、当該一体型中性子吸収要素の前記中性子吸収材における前記シースと対向する面に、制御棒挿抜方向に略平行な縦溝が形成され、この縦溝は、制御棒挿入先端方向において前記中央構造材から前記ウイング側端方向へ向かって傾斜し、この縦溝の方向が、前記一体型中性子吸収要素の対向する複数枚の前記中性子吸収材相互間で略平行に設けられたことを特徴とするものである。 In the present invention, a long sheath opening having a U-shaped cross section is fixed to a central structural member to form a plurality of wings, and the distal structural member is inserted at the distal end side of the wing in the core insertion direction. A nuclear reactor in which a terminal structural member is fixed to each end side and a plurality of integrated neutron absorbing elements having plate-like hafnium as a main neutron absorbing material are accommodated in a row in the longitudinal direction of the sheath in the sheath In the control rod, the thickness of the neutron absorbing material is within a range from 1/4 to 3/4 from the insertion tip among the plurality of integrated neutron absorbing elements arranged in the control rod insertion / extraction direction. In the integrated neutron absorbing element located on the control rod insertion tip side that is thicker than the vertical axis, a vertical groove substantially parallel to the control rod insertion / extraction direction is formed on the surface of the integrated neutron absorbing element facing the sheath in the neutron absorber. It is, the longitudinal groove The control rod insertion tip direction is inclined from the central structural member toward the wing side end direction, and the direction of the longitudinal groove is substantially between the plurality of neutron absorbers facing the integrated neutron absorbing element. It is characterized by being provided in parallel .

本発明によれば、制御棒挿抜方向に配列された複数の一体型中性子吸収要素のうち、挿入先端から１／４乃至３／４の範囲で、中性子吸収材の厚さがシースの厚さよりも厚い制御棒挿入先端側に位置する一体型中性子吸収要素では、当該一体型中性子吸収要素の中性子吸収材におけるシースと対向する面に、制御棒挿抜方向に略平行な縦溝が形成されている。このため、中性子吸収材とシースとの間の通水性が良好となり、これらの中性子吸収材とシースとの冷却性が高まると共に、これら両者間に隙間腐食が発生することを防止できる。また、中性子吸収材に上記縦溝が形成されたことで、中性子吸収材とシースとが接触する場合の接触面積を減少でき、これらの中性子吸収材とシースとの相対移動が容易化される。更に、中性子吸収材に上記縦溝が形成されることで、この中性子吸収材における制御棒挿抜方向に対し直角方向の柔軟性を向上させることができる。これらのことから、健全性を確保しつつ、原子炉用制御棒の長寿命化を実現できる。   According to the present invention, among the plurality of integrated neutron absorbing elements arranged in the control rod insertion / extraction direction, the thickness of the neutron absorber is greater than the thickness of the sheath in the range of 1/4 to 3/4 from the insertion tip. In the integrated neutron absorbing element located on the thick control rod insertion tip side, a longitudinal groove substantially parallel to the control rod insertion / extraction direction is formed on the surface of the integrated neutron absorbing element facing the sheath of the neutron absorber. For this reason, the water permeability between the neutron absorbing material and the sheath is improved, the cooling performance between the neutron absorbing material and the sheath is improved, and crevice corrosion can be prevented from occurring between them. In addition, since the longitudinal grooves are formed in the neutron absorber, the contact area when the neutron absorber and the sheath are in contact can be reduced, and the relative movement between the neutron absorber and the sheath is facilitated. Furthermore, by forming the longitudinal grooves in the neutron absorber, flexibility in the direction perpendicular to the control rod insertion / extraction direction of the neutron absorber can be improved. From these facts, it is possible to extend the life of the reactor control rod while ensuring soundness.

以下、本発明を実施するための最良の形態を、図面に基づき説明する。但し、本発明は、これらの実施の形態に限定されるものではない。また、各実施の形態において、前記背景技術(従来技術)と同様な部分は、同一の符号を付すことにより説明を省略する。   The best mode for carrying out the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments. In each embodiment, the same parts as those in the background art (prior art) are denoted by the same reference numerals, and the description thereof is omitted.

［Ａ］第１の実施の形態（図１〜図３）
図１は、本発明に係る原子炉用制御棒の第１の実施の形態における主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図である。図２（Ａ）、（Ｂ）、（Ｃ）、（Ｄ）は、図１のIIＡ‐IIＡ線、IIＢ‐IIＢ線、IIＣ‐IIＣ線、IIＤ‐IIＤ線にそれぞれ沿う断面図である。 [A] First embodiment (FIGS. 1 to 3)
FIG. 1 is a front view showing an integral neutron absorbing element as a main part in a first embodiment of a control rod for a nuclear reactor according to the present invention, in which a front sheath is notched. 2A, 2B, 2C, and 2D are cross-sectional views taken along lines IIA-IIA, IIB-IIB, IIC-IIC, and IID-IID in FIG. 1, respectively.

本実施の形態の原子炉用制御棒３０は、横断面が深いＵ字形状をなす長尺のシース７の開口部を中央構造材６に固着して複数のウイング２を構成し、このウイング２の炉心挿入方向先端側に先端構造材４を、挿入末端側に末端構造材５をそれぞれ固着すると共に、中性子吸収材としての２枚のハフニウム板１０を備えてなる一体型中性子吸収要素３１が、シース７の長尺方向に複数個配列して収容されて構成されたものである。この一体型中性子吸収要素３１は、原子炉用制御棒３０の挿抜方向に同一長さ（例えば４５ｃｍ程度）で、シース７の長尺方向に例えば８個配列されている。   The nuclear reactor control rod 30 of the present embodiment forms a plurality of wings 2 by fixing the opening of a long sheath 7 having a deep U-shaped cross section to the central structural member 6. An integrated neutron absorbing element 31 comprising a tip structural member 4 fixed to the distal end side of the core insertion direction and a terminal structural member 5 fixed to the insertion end side, and two hafnium plates 10 serving as neutron absorbers are provided. A plurality of sheaths 7 are arranged and accommodated in the longitudinal direction. For example, eight integrated neutron absorbing elements 31 are arranged in the longitudinal direction of the sheath 7 with the same length (for example, about 45 cm) in the insertion / extraction direction of the reactor control rod 30.

各一体型中性子吸収要素３１は、挿入先端側、挿入末端側に各一対設けられた保持部材３２によってシース７に荷重が保持される。つまり、保持部材３２は、図２(Ｂ)に示すように、スペーサ部１２Ａと同一形状のスペーサ部３２Ａと、軸部１２Ｂとは異なる形状の軸部３２Ｂとを有してなる。スペーサ部３２Ａは、一体型中性子吸収要素３１の２枚のハフニウム板１０間に配置されて、これらのハフニウム板１０の間隙を水ギャップ１１として保持する。また、軸部３２Ｂは、一体型中性子吸収要素３１における２枚のハフニウム板１０の挿入先端側に設けられた貫通孔３３、または挿入末端側に設けられた貫通孔３４に挿通され、更にシース７の装着孔８に挿通されて、先端がこのシース７の外面から突出しないようにして当該外面に溶接等により固着される。このようにして、軸部３２Ｂは、対向するシース７の間隔を保持すると共に、ハフニウム板１０の荷重をシース７に保持させる。   In each integrated neutron absorbing element 31, the load is held in the sheath 7 by the holding members 32 provided on the insertion tip side and the insertion end side. That is, as shown in FIG. 2B, the holding member 32 includes a spacer portion 32A having the same shape as the spacer portion 12A, and a shaft portion 32B having a shape different from that of the shaft portion 12B. The spacer portion 32 </ b> A is disposed between the two hafnium plates 10 of the integrated neutron absorbing element 31 and holds the gap between these hafnium plates 10 as the water gap 11. Further, the shaft portion 32B is inserted into the through hole 33 provided on the insertion tip side of the two hafnium plates 10 in the integrated neutron absorption element 31 or the through hole 34 provided on the insertion end side, and further the sheath 7 And is fixed to the outer surface by welding or the like so that the tip does not protrude from the outer surface of the sheath 7. In this manner, the shaft portion 32 </ b> B maintains the distance between the facing sheaths 7 and holds the load of the hafnium plate 10 on the sheath 7.

制御棒挿抜方向に複数個（例えば８個）配列された一体型中性子吸収要素３１のうち、挿入先端から１／４乃至３／４程度の範囲に位置する一体型中性子吸収要素（以下、「制御棒挿入先端側に位置する一体型中性子吸収要素」と称する）３１では、ハフニウム板１０の板厚がシース７の板厚よりも厚く形成されている。これは、この制御棒挿入先端側に位置する一体型中性子吸収要素３１の反応度価値、つまり原子炉の反応度を制御する中性子吸収能力を高め、且つ高い中性子照射を受けても上記反応度価値を良好に維持できるようにするためである。   Of the integrated neutron absorbing elements 31 arranged in a plurality (for example, eight) in the control rod insertion / extraction direction, the integrated neutron absorbing elements (hereinafter referred to as “control”) located in a range of about ¼ to ¾ from the insertion tip. In an integrated neutron absorbing element 31) located on the rod insertion tip side, the thickness of the hafnium plate 10 is greater than the thickness of the sheath 7. This enhances the reactivity value of the integrated neutron absorption element 31 located on the control rod insertion tip side, that is, the neutron absorption ability for controlling the reactivity of the reactor, and the above reactivity value even when subjected to high neutron irradiation. This is because it can be maintained well.

このような制御棒挿入先端側に位置する各一体型中性子吸収要素３１では、図１及び図２（Ａ）に示すように、この一体型中性子吸収要素３１を構成するハフニウム板１０のシース７と対向する外側面４１に、制御棒挿抜方向に平行に延びる１本または複数本(本実施の形態では複数本)の縦溝４２が形成されている。この縦溝４２の深さは、当該縦溝４２の底から、ハフニウム板１０の縦溝４２が形成されていない内側面４３までの肉厚Ｍ１が、シース７の肉厚Ｎ以上となる範囲で設定される。   In each integrated neutron absorbing element 31 positioned on the control rod insertion tip side, as shown in FIGS. 1 and 2A, the sheath 7 of the hafnium plate 10 constituting the integrated neutron absorbing element 31 and One or a plurality (in the present embodiment, a plurality of) vertical grooves 42 extending in parallel with the control rod insertion / extraction direction are formed on the opposing outer surface 41. The depth of the vertical groove 42 is such that the thickness M1 from the bottom of the vertical groove 42 to the inner surface 43 where the vertical groove 42 of the hafnium plate 10 is not formed is equal to or greater than the thickness N of the sheath 7. Is set.

例えば、縦溝４２は、ハフニウム板１０の厚さが仮に１．６ｍｍであるとき、ハフニウム板１０の外側面４１に溝ピッチｐが１０ｍｍで、溝幅ｗが３ｍｍ、溝深さｈが０．８ｍｍとなるような断面円弧形状の溝である。この場合、縦溝４２のないハフニウム板に比べ、当該ハフニウム板１０の横断面積は約８％程度減少し、モンテカルロ法による統計精度の高い計算を行ったところ、当該原子炉用制御棒３０の反応度価値は１．３％程度低下した。また、縦溝４２は、ハフニウム板１０の厚さが同程度であるとき、ハフニウム板１０の外側面４１に溝ピッチｐが５ｍｍで、溝幅ｗが３ｍｍ、溝深さｈが０．４ｍｍとなるような断面円弧形状の溝としてもよい。この場合には、縦溝４２のないハフニウム板に比べ、当該ハフニウム板１０の横断面積は約７％程度減少し、原子炉用制御棒３０の反応度価値は、同様の計算によって１．２％程度低下した。   For example, when the thickness of the hafnium plate 10 is 1.6 mm, the vertical groove 42 has a groove pitch p of 10 mm, a groove width w of 3 mm, and a groove depth h of 0.1 mm on the outer surface 41 of the hafnium plate 10. It is a groove having a cross-sectional arc shape of 8 mm. In this case, the cross-sectional area of the hafnium plate 10 is reduced by about 8% as compared with the hafnium plate without the longitudinal grooves 42, and the calculation of the statistical accuracy by the Monte Carlo method is performed. The degree value fell by about 1.3%. Further, when the thickness of the hafnium plate 10 is approximately the same, the longitudinal groove 42 has a groove pitch p of 5 mm, a groove width w of 3 mm, and a groove depth h of 0.4 mm on the outer surface 41 of the hafnium plate 10. It is good also as a groove | channel of such a cross-sectional arc shape. In this case, the cross-sectional area of the hafnium plate 10 is reduced by about 7% compared to the hafnium plate without the longitudinal groove 42, and the reactivity value of the reactor control rod 30 is 1.2% by the same calculation. Degraded.

ハフニウム板１０におけるシース７に対向した外側面４１に上述の縦溝４２を設けることによって、ハフニウム板１０のシース７との間の通水性が良好となり、これらのハフニウム板９とシース７との通水に伴う冷却性が高まると共に、ハフニウム板１０とシース７との間に隙間腐食が生ずることが防止される。また、ハフニウム板１０の外側面４１に縦溝４２が形成されたことで、ハフニウム板１０とシース７とが接触した場合の接触面積が低下し、これらのハフニウム板１０とシース７との相対移動が容易化される。更に、ハフニウム板１０の外側面４１に縦溝４２が形成されることで、このハフニウム板１０における制御棒挿抜方向に対し直角方向の柔軟性が高まり、またハフニウム板１０とシース７との機械的強度が同程度となる。このハフニウム板１０の機械的強度は、ハフニウム板１０において縦溝４２の底からの肉厚Ｍ１がシース７の肉厚Ｎ以上に設定されていることからも担保され、ハフニウム板１０の機械的な強度低下が回避される。   By providing the vertical groove 42 on the outer surface 41 of the hafnium plate 10 facing the sheath 7, the water permeability between the hafnium plate 10 and the sheath 7 is improved, and the passage between the hafnium plate 9 and the sheath 7 is improved. While the cooling property accompanying water increases, crevice corrosion between the hafnium plate 10 and the sheath 7 is prevented. Further, since the longitudinal groove 42 is formed on the outer surface 41 of the hafnium plate 10, the contact area when the hafnium plate 10 and the sheath 7 are in contact with each other is reduced, and the relative movement between the hafnium plate 10 and the sheath 7 is reduced. Is facilitated. Further, the longitudinal groove 42 is formed on the outer surface 41 of the hafnium plate 10, so that the flexibility in the direction perpendicular to the control rod insertion / removal direction of the hafnium plate 10 is increased, and the mechanical properties of the hafnium plate 10 and the sheath 7 are increased. The strength is comparable. The mechanical strength of the hafnium plate 10 is ensured because the thickness M1 from the bottom of the longitudinal groove 42 in the hafnium plate 10 is set to be equal to or greater than the thickness N of the sheath 7, and the mechanical strength of the hafnium plate 10 is guaranteed. A reduction in strength is avoided.

また、図１及び図２（Ｂ）に示すように、制御棒挿入先端側に位置する一体型中性子吸収要素３１では、この一体型中性子吸収要素３１における挿入先端側の貫通孔３３と挿入末端側の貫通孔３４のうちのいずれか一方、本実施の形態では貫通孔３４が制御棒挿抜方向に延びる長孔に形成されている。これにより、貫通孔３４に挿通される保持部材３２の軸部３２Ｂと当該貫通孔３４との間に、軸部３２Ｂが制御棒挿抜方向に移動可能な孔隙間３７が形成されることになる。また、上記貫通孔３３に挿通される保持部材３２の軸部３２Ｂは、実際には、貫通孔３４に挿通される軸部３２Ｂよりも大径に形成されて強度が増大されている。従って、この貫通孔３３は、当該軸部３２Ｂよりも若干大きな直径の真円形状に形成されている。この貫通孔３３を挿通する保持部材３２の軸部３２Ｂによって、一体型中性子吸収要素３１の荷重がシース７に保持される。   Moreover, as shown in FIG.1 and FIG.2 (B), in the integrated neutron absorption element 31 located in the control rod insertion front end side, the insertion hole side through-hole 33 and insertion end side in the integrated neutron absorption element 31 In the present embodiment, the through hole 34 is formed as a long hole extending in the control rod insertion / extraction direction. As a result, a hole gap 37 is formed between the shaft portion 32B of the holding member 32 inserted through the through hole 34 and the through hole 34 so that the shaft portion 32B can move in the control rod insertion / extraction direction. Further, the shaft portion 32B of the holding member 32 inserted through the through hole 33 is actually formed to have a larger diameter than the shaft portion 32B inserted through the through hole 34, and the strength is increased. Therefore, the through hole 33 is formed in a perfect circle shape having a slightly larger diameter than the shaft portion 32B. The load of the integral neutron absorbing element 31 is held in the sheath 7 by the shaft portion 32B of the holding member 32 inserted through the through hole 33.

シース７を構成するステンレス鋼（ＳＵＳ）もハフニウム板１０も中性子照射によって照射成長する。原子炉用制御棒３０の照射成長は、当該原子炉用制御棒３０において挿入先端から１／４乃至３／４の範囲の制御棒挿入先端側に位置する一体型中性子吸収要素３１において著しい。このシース７とハフニウム板１０との照射特性は、照射が非常に進んだ段階では実測データが不足している。しかし、このような場合でも、ハフニウム板１０の貫通孔３４に挿通される保持部材３２の軸部３２Ｂと当該貫通孔３４との間で、保持部材３２の軸部３２Ｂが制御棒挿抜方向に移動可能な孔隙間３７が形成されることで、この保持部材３２を介してハフニウム板１０とシース７とが制御棒挿抜方向に移動可能となる。これにより、中性子照射成長が非常に進んだ段階でも、ハフニウム板１０とシース７との熱膨張・熱収縮などに伴い発生する機械的応力の発生を防止でき、原子炉用制御棒３０の機械的な健全性が確保される。   Both stainless steel (SUS) and hafnium plate 10 constituting the sheath 7 are irradiated and grown by neutron irradiation. The irradiation growth of the reactor control rod 30 is significant in the integrated neutron absorbing element 31 located on the control rod insertion tip side in a range of ¼ to ¾ from the insertion tip of the reactor control rod 30. As for the irradiation characteristics of the sheath 7 and the hafnium plate 10, measured data are insufficient at the stage where the irradiation is very advanced. However, even in such a case, the shaft portion 32B of the holding member 32 moves in the control rod insertion / extraction direction between the shaft portion 32B of the holding member 32 inserted through the through hole 34 of the hafnium plate 10 and the through hole 34. By forming the possible hole gap 37, the hafnium plate 10 and the sheath 7 can move in the control rod insertion / extraction direction via the holding member 32. Thereby, even when the neutron irradiation growth is very advanced, it is possible to prevent the generation of mechanical stress caused by thermal expansion / contraction of the hafnium plate 10 and the sheath 7, and the mechanical control rod 30 for the reactor is mechanically generated. Soundness is ensured.

また、保持部材３２の軸部３２Ｂとの間で孔間隙３７を形成するハフニウム板１０の貫通孔３４が長孔に形成されたので、ハフニウム板１０とシース７との必要な相対移動量を確保しつつ、貫通孔３４の孔面積の増大が防止される。このため、この貫通孔３４の形成によっても、ハフニウム板１０の反応度価値の低下が抑制される。   Further, since the through-hole 34 of the hafnium plate 10 that forms the hole gap 37 between the holding member 32 and the shaft portion 32B is formed as a long hole, a necessary relative movement amount between the hafnium plate 10 and the sheath 7 is ensured. However, an increase in the hole area of the through hole 34 is prevented. For this reason, the formation of the through hole 34 also suppresses a decrease in the reactivity value of the hafnium plate 10.

制御棒挿入先端側に位置する一体型中性子吸収要素３１では、これらのすべての一体型中性子吸収要素３１において、上述のように、孔間隙３７が挿入末端側に統一して形成されて、挿入先端側の保持部材３２がハフニウム板１０とシース７との制御棒挿抜方向の相対移動を規制して、一体型中性子吸収要素３１の荷重をシース７に保持させ、挿入末端側の保持部材３２がハフニウム板１０とシース７との制御棒挿抜方向の相対移動を許容するよう構成されている。これにより、制御棒挿抜方向に隣接する各一体型中性子吸収要素３１は、境界において衝突することが防止され、または衝突を回避するために、隣接する一体型中性子吸収要素３１の間隔を過大に設定する必要がない。   In the integrated neutron absorbing element 31 positioned on the control rod insertion tip side, in all of these integrated neutron absorption elements 31, the hole gap 37 is formed uniformly on the insertion end side as described above, and the insertion tip The holding member 32 on the side regulates the relative movement of the hafnium plate 10 and the sheath 7 in the control rod insertion / removal direction so that the load of the integrated neutron absorbing element 31 is held by the sheath 7, and the holding member 32 on the insertion end side is the hafnium The plate 10 and the sheath 7 are configured to allow relative movement in the control rod insertion / extraction direction. Thereby, each integrated neutron absorbing element 31 adjacent in the control rod insertion / extraction direction is prevented from colliding at the boundary, or in order to avoid the collision, the interval between adjacent integrated neutron absorbing elements 31 is set excessively. There is no need to do.

或いは、制御棒挿入先端側に位置するすべての一体型中性子吸収要素３１では、孔間隙３７が挿入先端側に統一して形成されて、挿入末端側の保持部材３２がハフニウム板１０とシース７の制御棒挿抜方向の相対移動を規制して、一体型中性子吸収要素３１の荷重をシース７に保持させ、挿入先端側の保持部材３２がハフニウム板１０とシース７との制御棒挿抜方向の相対移動を許容するよう構成されている。   Alternatively, in all the integrated neutron absorbing elements 31 positioned on the control rod insertion tip side, the hole gap 37 is formed uniformly on the insertion tip side, and the holding member 32 on the insertion end side is formed between the hafnium plate 10 and the sheath 7. The relative movement in the control rod insertion / removal direction is restricted, the load of the integrated neutron absorbing element 31 is held by the sheath 7, and the holding member 32 on the insertion tip side moves relative to the hafnium plate 10 and the sheath 7 in the control rod insertion / removal direction. Is configured to allow.

ここで、上記保持部材３２の軸部３２Ｂは、図３に示すように、一体型中性子吸収要素３１の２枚のハフニウム板１０の貫通孔３３、３４を挿通する大径部３８と、シース７の装着孔８を挿通する小径部３９とを備えて構成される。大径部３８は、小径部３９よりも若干大径に形成されて、両者の境界に段差部４０が設けられる。小径部３９は、シース７の厚さとほぼ等しい長さに設定されて、その先端がシース７の外面に溶接等により固着される。また、大径部３８は、スペーサ部３２Ａから上記段差部４０に至る長さの領域であり、その長さは、ハフニウム板１０の厚さｔよりも所定寸法δだけ長く設定されている。この所定寸法δの値は、例えば０．２〜０．６ｍｍである。   Here, as shown in FIG. 3, the shaft portion 32 </ b> B of the holding member 32 includes a large diameter portion 38 through which the through holes 33 and 34 of the two hafnium plates 10 of the integrated neutron absorbing element 31 are inserted, and the sheath 7. And a small-diameter portion 39 through which the mounting hole 8 is inserted. The large diameter portion 38 is formed to have a slightly larger diameter than the small diameter portion 39, and a stepped portion 40 is provided at the boundary between them. The small diameter portion 39 is set to a length substantially equal to the thickness of the sheath 7, and its tip is fixed to the outer surface of the sheath 7 by welding or the like. The large-diameter portion 38 is a region extending from the spacer portion 32A to the stepped portion 40, and the length is set longer than the thickness t of the hafnium plate 10 by a predetermined dimension δ. The value of the predetermined dimension δ is, for example, 0.2 to 0.6 mm.

大径部３８がハフニウム板１０の厚さｔよりも所定寸法δだけ長く設定されたことで、ハフニウム板１０とシース７との間、及びハフニウム板１０と保持部材３２のスペーサ部３２Ａとの間に微小な隙間が形成され、ハフニウム板１０は厚さ方向に微小移動可能に設けられる。これにより、ハフニウム板１０とシース７とが制御棒挿抜方向に相対移動可能に構成され、この相対移動は、ハフニウム板１０の外側面４１に形成された縦溝４２の存在によるハフニウム板１０とシース７との接触面積の減少により更に促進される。また、このようなハフニウム板１０とシース７との相対移動により、これらのハフニウム板１０とシース７との間の通水性も高まり、これらのハフニウム板１０とシース７との通水による冷却性が向上すると共に、これらのハフニウム板１０とシース７との間に腐食生成物が付着することが防止される。   Since the large-diameter portion 38 is set longer than the thickness t of the hafnium plate 10 by a predetermined dimension δ, between the hafnium plate 10 and the sheath 7 and between the hafnium plate 10 and the spacer portion 32A of the holding member 32. The hafnium plate 10 is provided so as to be movable in the thickness direction. Thus, the hafnium plate 10 and the sheath 7 are configured to be relatively movable in the control rod insertion / removal direction. This relative movement is caused by the presence of the longitudinal groove 42 formed in the outer surface 41 of the hafnium plate 10. This is further promoted by the reduction of the contact area with 7. Further, the relative movement between the hafnium plate 10 and the sheath 7 also increases the water permeability between the hafnium plate 10 and the sheath 7, and the cooling performance by the water flow between the hafnium plate 10 and the sheath 7 is improved. In addition to the improvement, corrosion products are prevented from adhering between the hafnium plate 10 and the sheath 7.

なお、保持部材３２の小径部３９の先端をシース７の外面に溶接する際に、シース７の内面を保持部材３２の段差部４０に当接することで、保持部材３２のスペーサ部３２Ａとシース７との距離を大径部３８の長さに一致させることが可能となり、ハフニウム板１０がシース７、スペーサ部３２Ａに押し付けられて、これらの間に摩擦力が生ずることが防止される。また、上記大径部３８及び小径部３９を備えてなる軸部３２Ｂを有する保持部材３２は、制御棒挿入先端側に位置する一体型中性子吸収要素３１に限らず、制御棒挿入末端側に位置する一体型中性子吸収要素３１に適用されてもよい。   When the tip of the small diameter portion 39 of the holding member 32 is welded to the outer surface of the sheath 7, the inner surface of the sheath 7 is brought into contact with the stepped portion 40 of the holding member 32, so that the spacer portion 32 </ b> A of the holding member 32 and the sheath 7. Can be made to coincide with the length of the large-diameter portion 38, and the hafnium plate 10 is pressed against the sheath 7 and the spacer portion 32A, thereby preventing a frictional force from being generated therebetween. The holding member 32 having the shaft portion 32B having the large diameter portion 38 and the small diameter portion 39 is not limited to the integrated neutron absorbing element 31 located on the control rod insertion tip side, but is located on the control rod insertion end side. The integrated neutron absorbing element 31 may be applied.

また、図１に示すように、制御棒挿入先端側に位置する一体型中性子吸収要素３１において、挿入先端側と挿入末端側にそれぞれ一対設けられた保持部材３２は、制御棒挿抜方向に段違いに配置されている。保持部材３２は、シース７に溶接により固着されている。このシース７の保持部材３２溶接箇所では、発生した残留応力を完全に除去することは容易でなく、中性子照射量が高くなった場合に応力腐食割れが発生する恐れがある。しかし、保持部材３２が制御棒挿抜方向に段違いに配置されたことで、シース７において制御棒挿抜方向に直角な方向の同一断面で残留応力が低減されるので、応力腐食割れの発生が抑制される。   Further, as shown in FIG. 1, in the integrated neutron absorbing element 31 positioned on the control rod insertion tip side, the holding members 32 provided in pairs on the insertion tip side and the insertion end side are stepped in the control rod insertion / extraction direction. Is arranged. The holding member 32 is fixed to the sheath 7 by welding. At the location where the holding member 32 of the sheath 7 is welded, it is not easy to completely remove the generated residual stress, and stress corrosion cracking may occur when the amount of neutron irradiation increases. However, since the holding members 32 are arranged stepwise in the control rod insertion / removal direction, the residual stress is reduced in the same cross section in the direction perpendicular to the control rod insertion / removal direction in the sheath 7, so that the occurrence of stress corrosion cracking is suppressed. The

このような挿入先端側と挿入末端側での一対の保持部材３２の段違い配置は、制御棒挿入先端側に位置する一体型中性子吸収要素３１に限らず、制御棒挿入末端側に位置する一体型中性子吸収要素３１にも適用可能である。   Such a different arrangement of the pair of holding members 32 on the insertion tip side and the insertion end side is not limited to the integrated neutron absorbing element 31 located on the control rod insertion tip side, but is an integral type located on the control rod insertion end side. The present invention can also be applied to the neutron absorbing element 31.

図１、図２(Ｃ)及び(Ｄ)に示すように、原子炉用制御棒３０の一体型中性子吸収要素３１及びシース７には、シース通水孔９Ａ、重複通水孔９Ｂが通水孔９として設けられている。図１中では、シース７に形成された通水用の孔は破線で示している。シース通水孔９Ａからの水の導入によって、シース７及びハフニウム板１０が冷却される。また、重複通水孔９Ｂから一体型中性子吸収要素３１のハフニウム板１０間の水ギャップ１１へ水が導入され、この水が高速中性子の減速用、及びハフニウム板１０の冷却用に利用される。   As shown in FIGS. 1, 2C and 2D, the integral neutron absorbing element 31 and the sheath 7 of the nuclear reactor control rod 30 are provided with a sheath water passage hole 9A and an overlapping water passage hole 9B. It is provided as a hole 9. In FIG. 1, holes for water passage formed in the sheath 7 are indicated by broken lines. The sheath 7 and the hafnium plate 10 are cooled by introducing water from the sheath water passage hole 9A. Further, water is introduced into the water gap 11 between the hafnium plates 10 of the integrated neutron absorbing element 31 from the overlapping water passage hole 9B, and this water is used for slowing down fast neutrons and cooling the hafnium plate 10.

上記シース通水孔９Ａ、重複通水孔９Ｂのうち、制御棒挿入先端側に位置する一体型中性子吸収要素３１に対応してシース７に形成されるシース通水孔９Ａ、重複通水孔９Ｂは、制御棒挿抜方向に対し直角な方向に２個並設されず、制御棒挿抜方向に段違いに設けられる。シース７にシース通水孔９Ａ等が上述のように２個並設されると、シース通水孔９Ａ等を含むシース７の横断面ではせん断応力が約３０％程度増大するが、シース通水孔９Ａなどの通水孔９を制御棒挿抜方向に段違いに配置することで、上記せん断応力の増大が抑制されて、シース７の強度が向上する。   Of the sheath water hole 9A and the overlapping water hole 9B, the sheath water hole 9A and the overlapping water hole 9B formed in the sheath 7 corresponding to the integrated neutron absorbing element 31 located on the control rod insertion tip side. Are not provided side by side in a direction perpendicular to the control rod insertion / extraction direction, but are provided in a stepped manner in the control rod insertion / extraction direction. When the two sheath water holes 9A and the like are arranged in the sheath 7 as described above, the shear stress increases by about 30% in the cross section of the sheath 7 including the sheath water holes 9A and the like. By arranging the water passage holes 9 such as the holes 9A in a stepwise manner in the control rod insertion / extraction direction, an increase in the shear stress is suppressed, and the strength of the sheath 7 is improved.

制御棒挿入先端側に位置する一体型中性子吸収要素３１では、上記重複通水孔９Ｂは、シース７に形成されたシース孔９Ｂ１と、ハフニウム板１０に形成されたハフニウム孔９Ｂ２とが重複して設けられた通水孔であり、このうちハフニウム孔９Ｂ２が、制御棒挿抜方向に延びる長孔に形成される。制御棒挿入先端側に位置する一体型中性子吸収要素３１においては、ハフニウム板１０とシース７との照射成長が著しい。従って、重複通水孔９Ｂを構成するハフニウム孔９Ｂ２を制御棒挿抜方向に延びる長孔に形成することで、中性子照射が非常に進み、ハフニウム板１０とシース７との間に熱膨張・熱収縮に伴う制御棒挿抜方向の相対的な位置ずれが発生しても、シース孔９Ｂ１とハフニウム孔９Ｂ２とが一致した状態に維持される。これにより、一体型中性子吸収要素３１の水ギャップ１１とシース７外部との間で重複通水孔９Ｂを通した水の出入が確保され、このため、ハフニウム板１２の冷却性が良好に確保される。   In the integrated neutron absorbing element 31 positioned on the control rod insertion tip side, the overlapping water passage hole 9B is formed by overlapping the sheath hole 9B1 formed in the sheath 7 with the hafnium hole 9B2 formed in the hafnium plate 10. Among these holes, the hafnium hole 9B2 is formed as a long hole extending in the control rod insertion / extraction direction. In the integrated neutron absorbing element 31 located on the control rod insertion tip side, the irradiation growth of the hafnium plate 10 and the sheath 7 is remarkable. Therefore, by forming the hafnium hole 9B2 constituting the overlapping water passage hole 9B into a long hole extending in the control rod insertion / extraction direction, neutron irradiation is greatly advanced, and thermal expansion / contraction between the hafnium plate 10 and the sheath 7 is achieved. Even if the relative displacement in the control rod insertion / removal direction is caused, the sheath hole 9B1 and the hafnium hole 9B2 are maintained in a matched state. As a result, it is ensured that water enters and exits through the overlapping water passage hole 9B between the water gap 11 of the integrated neutron absorbing element 31 and the outside of the sheath 7, and thus the cooling performance of the hafnium plate 12 is ensured satisfactorily. The

以上のように構成されたことから、上記実施の形態によれば、次の効果（１）〜（６）を奏する。   With the configuration as described above, the following effects (1) to (6) are achieved according to the above embodiment.

（１）制御棒挿入先端側に位置する一体型中性子吸収要素３１では、当該一体型中性子吸収要素３１のハフニウム板１０におけるシース７との対向する外側面４１に、制御棒挿抜方向に略平行な複数本の縦溝４２が形成されている。このため、ハフニウム板１０とシース７との間の通水性が良好となり、これらのハフニウム板１０とシース７との通水による冷却性が高まると共に、これらの両者間に隙間腐食が発生することを防止できる。また、ハフニウム板１０に上記縦溝４２が形成されたことで、ハフニウム板１０とシース７とが接触する場合の接触面積を減少でき、これらのハフニウム板１０とシース７との相対移動が容易化する。更に、ハフニウム板１０に上記縦溝４２が形成されることで、このハフニウム板１０における制御棒挿抜方向に対し直角方向の柔軟性を向上させることができる。これらのことから、健全性を確保しつつ、原子炉用制御棒３０の長寿命化を実現できる。   (1) In the integrated neutron absorbing element 31 positioned on the control rod insertion distal end side, the outer surface 41 of the integrated neutron absorbing element 31 facing the sheath 7 in the hafnium plate 10 is substantially parallel to the control rod insertion / extraction direction. A plurality of vertical grooves 42 are formed. For this reason, the water permeability between the hafnium plate 10 and the sheath 7 is improved, the cooling performance by the water flow between the hafnium plate 10 and the sheath 7 is enhanced, and crevice corrosion occurs between them. Can be prevented. Further, since the longitudinal grooves 42 are formed in the hafnium plate 10, the contact area when the hafnium plate 10 and the sheath 7 are in contact with each other can be reduced, and the relative movement between the hafnium plate 10 and the sheath 7 is facilitated. To do. Furthermore, by forming the vertical groove 42 in the hafnium plate 10, the flexibility in the direction perpendicular to the control rod insertion / extraction direction in the hafnium plate 10 can be improved. From these facts, it is possible to extend the life of the nuclear reactor control rod 30 while ensuring soundness.

（２）ハフニウム板１０において縦溝４２の底からの肉厚Ｍ１が、シース７の肉厚Ｎ以上に設定されたことから、ハフニウム板１０の機械的な強度の低下を防止できる。   (2) Since the thickness M1 from the bottom of the longitudinal groove 42 in the hafnium plate 10 is set to be equal to or greater than the thickness N of the sheath 7, the mechanical strength of the hafnium plate 10 can be prevented from being lowered.

（３）制御棒挿入先端側に位置する一体型中性子吸収要素３１では、挿入末端側または挿入先端側のいずれか一方における一対の保持部材３２が挿入する貫通孔３４（または貫通孔３３）が、制御棒挿抜方向に延びる長孔に形成されたので、保持部材３２を介してハフニウム板１０とシース７とが制御棒挿抜方向に移動可能となる。この結果、中性子照射が非常に進み、ハフニウム板１０とシース７とに熱膨張・熱収縮が生じた場合にも、原子炉用制御棒３０の健全性を確保できる。また、上記貫通孔３４（または貫通孔３３）が長孔に形成されたので、ハフニウム板１０の反応度価値の低下を抑制できる。   (3) In the integrated neutron absorbing element 31 located on the control rod insertion tip side, the through holes 34 (or the through holes 33) into which the pair of holding members 32 are inserted on either the insertion end side or the insertion tip side are: Since it is formed in a long hole extending in the control rod insertion / extraction direction, the hafnium plate 10 and the sheath 7 can be moved in the control rod insertion / extraction direction via the holding member 32. As a result, even when neutron irradiation progresses so much that thermal expansion and contraction occur in the hafnium plate 10 and the sheath 7, the soundness of the nuclear reactor control rod 30 can be ensured. Moreover, since the said through-hole 34 (or through-hole 33) was formed in the long hole, the fall of the reactivity value of the hafnium plate 10 can be suppressed.

（４）保持部材３２の軸部３２Ｂが、ハフニウム板１０の厚さｔよりも所定寸法δだけ長い大径部３８と、シース７の厚さと同一長さの小径部３９とを備えて構成されたので、ハフニウム板１０とシース７との制御棒挿抜方向の相対移動を確保できる。この結果、ハフニウム板１０とシース７との間の通水性、冷却性を向上させ、腐食生成物の発生を防止できる。   (4) The shaft portion 32B of the holding member 32 includes a large diameter portion 38 longer than the thickness t of the hafnium plate 10 by a predetermined dimension δ, and a small diameter portion 39 having the same length as the thickness of the sheath 7. Therefore, relative movement of the hafnium plate 10 and the sheath 7 in the control rod insertion / removal direction can be ensured. As a result, water permeability and cooling performance between the hafnium plate 10 and the sheath 7 can be improved, and generation of corrosion products can be prevented.

（５）制御棒挿入先端側に位置する一体型中性子吸収要素３１では、重複通水孔９Ｂを構成するハフニウム孔９Ｂ２が制御棒挿抜方向に延びる長孔に形成されたので、原子炉用制御棒３０に中性子照射が非常に進み、ハフニウム板１０とシース７との間に熱膨張・熱収縮が生じた場合にも、シース孔９Ｂ１とハフニウム孔９Ｂ２とを一致した状態に維持することができる。このため、重複通水孔９Ｂを通して水の出入が確保され、ハフニウム板１０の冷却性を向上させることができる。   (5) In the integrated neutron absorbing element 31 located on the control rod insertion tip side, the hafnium hole 9B2 constituting the overlapping water passage hole 9B is formed as a long hole extending in the control rod insertion / removal direction. Even when the neutron irradiation progresses to 30 and thermal expansion / shrinkage occurs between the hafnium plate 10 and the sheath 7, the sheath hole 9B1 and the hafnium hole 9B2 can be maintained in the same state. For this reason, the entrance and exit of water is ensured through the overlapping water passage holes 9B, and the cooling performance of the hafnium plate 10 can be improved.

（６）一体型中性子吸収要素３１において、一対の保持部材３２が制御棒挿抜方向に段違いに配置されたので、シース７における制御棒挿抜方向に直角な方向の同一断面で、保持部材３２の溶接位置に生ずる残留応力を低減でき、応力腐食割れの発生を抑制できる。   (6) In the integrated neutron absorbing element 31, the pair of holding members 32 are arranged stepwise in the control rod insertion / extraction direction, so the welding of the holding member 32 is performed in the same cross section in the direction perpendicular to the control rod insertion / extraction direction in the sheath 7. The residual stress generated at the position can be reduced, and the occurrence of stress corrosion cracking can be suppressed.

［Ｂ］第２の実施の形態（図４、図５）
図４は、本発明に係る原子炉用制御棒の第２の実施の形態の主要部を示し、（Ａ）が図４（Ｂ）のIVＡ‐IVＡ線に沿う断面図、（Ｂ）が図4(Ａ)のIVＢ‐IVＢ線に沿う断面図である。この第２の実施の形態において、前記第１の実施の形態と同様な部分は、同一の符号を付すことにより説明棒省略する。 [B] Second embodiment (FIGS. 4 and 5)
FIG. 4 shows a main part of a second embodiment of the control rod for a reactor according to the present invention, in which (A) is a sectional view taken along the line IVA-IVA in FIG. 4 (B), and (B) is a diagram. It is sectional drawing which follows the IVB-IVB line | wire of 4 (A). In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the explanation rods are omitted.

この第２の実施の形態の原子炉用制御棒５０が前記第１の実施の形態の原子炉用制御棒３０と異なる点は、制御棒挿入先端側に位置する一体型中性子吸収要素５１のハフニウム板１０におけるシース７と対向する外側面４１に、制御棒挿抜方向と平行で、溝ピッチと溝深さが縦溝４２と異なる縦溝５２が形成された点である。   The reactor control rod 50 of the second embodiment is different from the reactor control rod 30 of the first embodiment in that the hafnium of the integrated neutron absorbing element 51 located on the control rod insertion tip side. A longitudinal groove 52 having a groove pitch and a groove depth different from the longitudinal groove 42 is formed on the outer surface 41 of the plate 10 facing the sheath 7 in parallel with the control rod insertion / extraction direction.

つまり、この縦溝５２は、図５に示すように、ハフニウム板１０の厚さが仮に１．６ｍｍであるときに、ハフニウム板１０の外側面４１に溝ピッチｐが２０ｍｍで、溝深さｈが０．２ｍｍ、溝幅ｗ１０ｍｍの棒断面略四角形状の溝である。この場合、縦溝５２のないハフニウム板と比べると、当該ハフニウム板１０の横断面積は約６％程度減少し、実施例１と同様な計算方法を用いて算出したところ、原子炉用制御棒５０の反応度価値は１％程度低下した。   That is, as shown in FIG. 5, when the thickness of the hafnium plate 10 is 1.6 mm, the longitudinal groove 52 has a groove pitch p of 20 mm on the outer surface 41 of the hafnium plate 10 and a groove depth h. Is a substantially square-shaped groove with a rod section of 0.2 mm and a groove width w of 10 mm. In this case, the cross-sectional area of the hafnium plate 10 is reduced by about 6% as compared with the hafnium plate without the longitudinal groove 52, and the control rod 50 for the nuclear reactor is calculated using the same calculation method as in the first embodiment. The reactivity value decreased by about 1%.

本実施の形態においても、制御棒挿入先端側に位置する一体型中性子吸収要素５１において、当該一体型中性子吸収要素５１のハフニウム板１０の外側面４１に、制御棒挿抜方向に平行な縦溝５２が形成されたこと等から、前記第１の実施の形態の効果（１）〜（６）と同様な効果を奏する。   Also in the present embodiment, in the integrated neutron absorbing element 51 positioned on the control rod insertion tip side, the longitudinal groove 52 parallel to the control rod insertion / extraction direction is formed on the outer surface 41 of the hafnium plate 10 of the integrated neutron absorbing element 51. Therefore, the same effects as the effects (1) to (6) of the first embodiment are obtained.

［Ｃ］第３の実施の形態（図６）
図６は、本発明に係る原子炉用制御棒の第３の実施の形態の主要部を示し、（Ａ）が図６（Ｂ）のVIＡ‐VIＡ線に沿う断面図、（Ｂ）が図６(Ａ)のVIＢ‐VIＢ線に沿う断面図である。この第３の実施の形態において、前記第１の実施の形態と同様な部分は、同一の符号を付すことにより説明を省略する。 [C] Third embodiment (FIG. 6)
FIG. 6 shows the main part of the third embodiment of the control rod for a nuclear reactor according to the present invention, in which (A) is a sectional view taken along the line VIA-VIA in FIG. 6 (B), and (B) is a diagram. It is sectional drawing which follows the VIB-VIB line of 6 (A). In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

この第３の実施の形態の原子炉用制御棒６０が、前記第１、第２の実施の形態の原子炉用制御棒３０、５０と異なる点は、制御棒挿入先端側に位置する一体型中性子吸収要素６１のハフニウム板１０における外側面４１に形成される縦溝６２の方向である。つまり、この縦溝６２は、制御棒挿入先端方向において中央構造体６からウイング２の側端６３方向へ向かって若干傾斜し、しかも、この縦溝６２の方向が一体型中性子吸収要素６１の対向する２枚のハフニウム板１０相互間において略平行に設けられている。   The reactor control rod 60 of the third embodiment is different from the reactor control rods 30 and 50 of the first and second embodiments in that it is an integrated type located on the control rod insertion tip side. This is the direction of the longitudinal groove 62 formed in the outer surface 41 of the hafnium plate 10 of the neutron absorbing element 61. That is, the longitudinal groove 62 is slightly inclined from the central structure 6 toward the side end 63 of the wing 2 in the control rod insertion tip direction, and the direction of the longitudinal groove 62 is opposite to the integrated neutron absorbing element 61. The two hafnium plates 10 are provided substantially parallel to each other.

従って、本実施の形態によれば、前記第１の実施の形態の効果（１）〜（６）と同様な効果を奏する他、次の効果（７）及び（８）を奏する。   Therefore, according to the present embodiment, the following effects (7) and (8) are obtained in addition to the same effects as the effects (1) to (6) of the first embodiment.

（７）縦溝６２が中央構造体６からウイング２の側端６３方向へ向かって若干傾斜して設けられたことから、中央構造体６側の比較的冷たい水が発熱率の高いウイング２の側端６３側へ導かれるので、ハフニウム板１０、ひいては一体型中性子吸収要素の６１の冷却効率を向上させることができる。   (7) Since the longitudinal groove 62 is provided slightly inclined from the central structure 6 toward the side edge 63 of the wing 2, relatively cool water on the central structure 6 side causes the wing 2 having a high heat generation rate. Since it is guided to the side end 63 side, the cooling efficiency of the hafnium plate 10 and thus the integrated neutron absorbing element 61 can be improved.

（８）一体型中性子吸収要素６１の２枚のハフニウム板１０のそれぞれに形成された縦溝６２が略平行に設けられたので、一体型中性子吸収要素６１の制御棒挿抜方向に対する直角方向の柔軟性を向上させることができる。   (8) Since the longitudinal grooves 62 formed in each of the two hafnium plates 10 of the integrated neutron absorption element 61 are provided substantially in parallel, the flexibility of the integrated neutron absorption element 61 in the direction perpendicular to the control rod insertion / extraction direction Can be improved.

［Ｄ］第４の実施の形態（図７）
図７は、本発明に係る原子炉用制御棒の第４の実施の形態の主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図である。この第４の実施の形態において、前記第１の実施の形態と同様な部分は、同一の符号を付すことにより説明を省略する。 [D] Fourth embodiment (FIG. 7)
FIG. 7 is a front view showing the integral neutron absorbing element, which is a main part of the fourth embodiment of the control rod for a nuclear reactor according to the present invention, in which a front sheath is notched. In the fourth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

この第４の実施の形態の原子炉用制御棒７０が、前記第１の実施の形態と異なる点は、制御棒挿入先端側に位置する一体型中性子吸収要素７１のハフニウム板１０におけるシース７と対向する外側面４１に、制御棒挿抜方向に対し直角な方向に延びる１本または複数本(本実施の形態では３本)の横溝７２が形成された点である。この横溝７２の深さは、縦溝４２、５２、６２の場合と同様に、当該横溝７２の底から、ハフニウム板１０の横溝７２が形成されていない内側面４３までの肉厚Ｍ１、Ｍ２が、シース７の肉厚Ｎ以上の範囲に設定される(図２(Ａ)、図５参照)。   The nuclear reactor control rod 70 of the fourth embodiment is different from the first embodiment in that the reactor 7 in the hafnium plate 10 of the integrated neutron absorbing element 71 located on the control rod insertion tip side is different from the first embodiment. One or a plurality (three in the present embodiment) of lateral grooves 72 extending in a direction perpendicular to the control rod insertion / extraction direction is formed on the opposing outer surface 41. As in the case of the longitudinal grooves 42, 52, 62, the depth of the lateral groove 72 is such that the thickness M 1, M 2 from the bottom of the lateral groove 72 to the inner side surface 43 where the lateral groove 72 of the hafnium plate 10 is not formed. The thickness is set to a range equal to or greater than the thickness N of the sheath 7 (see FIGS. 2A and 5).

上記横溝７２は、上記一体型中性子吸収要素７１におけるハフニウム板１０の外側面４１において、挿入先端側と挿入末端側の各保持部材３２を含む、これらの保持部材３２間の領域Ａに設けられる。尚、本実施の形態では、横溝７２が縦溝４２、５２または６２と共に、ハフニウム板１０の外側面４１に形成されるものを述べたが、横溝７２のみがハフニウム板１０の外側面４１に形成されてもよい。   The lateral groove 72 is provided in a region A between the holding members 32 including the holding members 32 on the insertion tip side and the insertion end side on the outer surface 41 of the hafnium plate 10 in the integrated neutron absorption element 71. In the present embodiment, the horizontal groove 72 is formed on the outer surface 41 of the hafnium plate 10 together with the vertical grooves 42, 52, or 62. However, only the horizontal groove 72 is formed on the outer surface 41 of the hafnium plate 10. May be.

本実施の形態によれば、前記第１の実施の形態の効果（１）〜（６）と同様な効果を奏する他、次の効果（９）〜（１１）を奏する。   According to the present embodiment, the following effects (9) to (11) are obtained in addition to the same effects as the effects (1) to (6) of the first embodiment.

（９）一体型中性子吸収要素７１を構成するステンレス鋼（ＳＵＳ）製のシース７とハフニウム板１０とは熱膨張率が異なると共に、中性子照射による照射成長の特性も異なる。原子炉用制御棒７０の照射成長は、原子炉用制御棒７０において、制御棒挿入先端側に位置する一体型中性子吸収要素７１において著しい。このシース７とハフニウム板１０との照射特性は、照射が非常に進んだ段階では実測データが不足している。このような一体型中性子吸収要素７１においては、挿入先端側の保持部材３２と挿入末端側の保持部材３２との間で中性子照射が著しく進み、シース７とハフニウム板１０との中性子照射特性が不明確となった場合、シース７がハフニウム板１０よりも熱膨張率が３倍程度大きいことから、特に熱収縮時に、シース７はハフニウム板１０から、制御棒挿抜方向に引きちぎられるようなせん断力を受けることがある。   (9) The stainless steel (SUS) sheath 7 and the hafnium plate 10 constituting the integrated neutron absorbing element 71 have different coefficients of thermal expansion and different irradiation growth characteristics by neutron irradiation. The irradiation growth of the nuclear reactor control rod 70 is significant in the integrated neutron absorbing element 71 located on the control rod insertion tip side in the nuclear reactor control rod 70. As for the irradiation characteristics of the sheath 7 and the hafnium plate 10, measured data are insufficient at the stage where the irradiation is very advanced. In such an integrated neutron absorbing element 71, the neutron irradiation proceeds remarkably between the holding member 32 on the insertion tip side and the holding member 32 on the insertion end side, and the neutron irradiation characteristics between the sheath 7 and the hafnium plate 10 are inferior. When it becomes clear, since the sheath 7 has a thermal expansion coefficient about three times larger than that of the hafnium plate 10, the sheath 7 has a shearing force that can be torn away from the hafnium plate 10 in the control rod insertion / removal direction particularly during thermal contraction. I may receive it.

しかし、上記一体型中性子吸収要素７１のハフニウム板１０の外側面４１に横溝７２が形成されたことで、一体型中性子吸収要素７１のハフニウム板１０は、制御棒挿抜方向に柔軟性が高まり、制御棒挿抜方向の圧縮強度が低下してシース７の引っ張り強度と同程度となる。このことから、シース７に亀裂等が生ずることを防止でき、一体型中性子吸収要素７１、ひいては原子炉用制御棒７０の健全性を確保できる。   However, since the lateral groove 72 is formed on the outer surface 41 of the hafnium plate 10 of the integrated neutron absorbing element 71, the hafnium plate 10 of the integrated neutron absorbing element 71 becomes more flexible in the control rod insertion / extraction direction, and the control The compressive strength in the rod insertion / removal direction is reduced to the same level as the tensile strength of the sheath 7. From this, it is possible to prevent the sheath 7 from being cracked, and to ensure the integrity of the integrated neutron absorbing element 71 and consequently the reactor control rod 70.

（１０）上記横溝７２は、交差して配置された複数の縦溝４２内を流れる水を均一化する機能を果たすので、一体型中性子吸収要素７１の冷却特性を向上させることができる。   (10) Since the horizontal groove 72 functions to make the water flowing through the plurality of vertical grooves 42 arranged intersecting each other, the cooling characteristics of the integrated neutron absorbing element 71 can be improved.

（１１）上記横溝７２の深さは、当該横溝７２の底からハフニウム板１０の内側面４３までの肉厚Ｍ１、Ｍ２が、シース７の肉厚Ｎ以上となる範囲で設定されるので、一体型中性子吸収要素７１におけるハフニウム板１０の強度を良好に確保できる。   (11) The depth of the lateral groove 72 is set so that the thicknesses M1 and M2 from the bottom of the lateral groove 72 to the inner surface 43 of the hafnium plate 10 are equal to or greater than the thickness N of the sheath 7. The strength of the hafnium plate 10 in the body-type neutron absorbing element 71 can be ensured satisfactorily.

［Ｅ］第５の実施の形態（図８）
図８は、本発明に係る原子炉用制御棒の第５の実施の形態の主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図である。この第５の実施の形態において、前記第１及び第４の実施の形態と同様な部分は、同一の符号を付すことにより説明を省略する。 [E] Fifth embodiment (FIG. 8)
FIG. 8 is a front view showing the integral neutron absorbing element, which is a main part of the fifth embodiment of the control rod for a nuclear reactor according to the present invention, with the front sheath cut away. In the fifth embodiment, the same parts as those of the first and fourth embodiments are denoted by the same reference numerals, and the description thereof is omitted.

この第２の実施の形態の原子炉用制御棒８０が前記第４の実施の形態の原子炉用制御棒７０と異なる点は、制御棒挿入先端側に位置する一体型中性子吸収要素８１において、通水孔９（シース通水孔９Ａ，重複通水孔９Ｂ）と一対の保持部材３２とが、制御棒挿抜方向に対し直角な方向に配置されると共に、横溝８２が挿入先端側と挿入末端側のそれぞれ一対の保持部材３２を含む幅で、制御棒挿抜方向に対し直角な方向に形成され、更にこれらの横溝８２間にも同様な横溝８３が、横溝８２に平行に形成された点である。これらの横溝８２及び８３は、前記横溝７２と同程度の溝深さに設定される。しかも、横溝８２及び８３には、ハフニウム板１０を貫通する溝通水孔８４が形成されて、一体型中性子吸収要素８１におけるハフニウム板１０間の水ギャップ１１とハフニウム板１０の外側面４１側とが連通される。   The difference between the nuclear reactor control rod 80 of the second embodiment and the nuclear reactor control rod 70 of the fourth embodiment is that in the integrated neutron absorption element 81 located on the control rod insertion tip side, The water passage hole 9 (sheath water passage hole 9A, overlapping water passage hole 9B) and the pair of holding members 32 are arranged in a direction perpendicular to the control rod insertion / extraction direction, and the lateral groove 82 is formed at the insertion tip side and the insertion end. It is a width including a pair of holding members 32 on each side, and is formed in a direction perpendicular to the control rod insertion / extraction direction. Further, a similar lateral groove 83 is formed between these lateral grooves 82 in parallel to the lateral grooves 82. is there. These lateral grooves 82 and 83 are set to a groove depth similar to that of the lateral groove 72. Moreover, in the lateral grooves 82 and 83, a groove water passage hole 84 penetrating the hafnium plate 10 is formed, and the water gap 11 between the hafnium plates 10 in the integrated neutron absorbing element 81 and the outer surface 41 side of the hafnium plate 10 are formed. Communicated.

従って、本実施の形態によれば、前記第１の実施の形態の効果（１）〜（５）、及び前記第４の実施の形態の効果（９）〜（１１）を奏する他、次の効果（１２）を奏する。   Therefore, according to this embodiment, in addition to the effects (1) to (5) of the first embodiment and the effects (9) to (11) of the fourth embodiment, the following There exists an effect (12).

（１２）一体型中性子吸収要素８１のハフニウム板１０の外側面４１に、制御棒挿抜方向に対し直角な方向に延びる横溝８２及び８３が形成され、これらの横溝８２、８３間に溝通水孔８４がハフニウム板１０に貫通して設けられている。従って、一体型中性子吸収要素８１の２枚のハフニウム板１０間における水ギャップ１１内の水がハフニウム板１０外へ容易に出入されて、このハフニウム板１０の冷却特性を向上させることができる。特に、横溝８２に溝通水孔８４が形成されたことで、一対の保持部材３２付近に蓄積されやすい滞留物が溝通水孔８４を流れる水によって蓄積されにくくなり、健全性の高い長寿命型の原子炉用制御棒８０を実現できる。   (12) The lateral grooves 82 and 83 extending in the direction perpendicular to the control rod insertion / extraction direction are formed on the outer surface 41 of the hafnium plate 10 of the integrated neutron absorbing element 81, and the groove water passage hole 84 is formed between the lateral grooves 82 and 83. Is provided penetrating through the hafnium plate 10. Therefore, the water in the water gap 11 between the two hafnium plates 10 of the integrated neutron absorbing element 81 can be easily put in and out of the hafnium plate 10 and the cooling characteristics of the hafnium plate 10 can be improved. In particular, since the groove water passage holes 84 are formed in the lateral grooves 82, the accumulated matter that tends to be accumulated in the vicinity of the pair of holding members 32 is less likely to be accumulated by the water flowing through the groove water holes 84. The reactor control rod 80 can be realized.

尚、本実施の形態によれば、前記第４の実施の形態の原子炉用制御棒７０と同様に、一体型中性子吸収要素８１のハフニウム板１０には、縦溝４２、５２または６２が設けられず、横溝８２及び８３にのみが設けられてもよい。   According to the present embodiment, the longitudinal grooves 42, 52, or 62 are provided in the hafnium plate 10 of the integrated neutron absorbing element 81, similarly to the reactor control rod 70 of the fourth embodiment. However, only the lateral grooves 82 and 83 may be provided.

［Ｆ］第６の実施の形態（図９〜図１１）
図９は、本発明に係る原子炉用制御棒の第６の実施の形態を示し、（Ａ）が左半分のシースを切り欠いて示す正面図、（Ｂ）が図９（Ａ）の一部拡大図である。この第６の実施の形態において、前記第１の実施の形態と同様な部分は、同一の符号を付すことにより説明を省略する。 [F] Sixth embodiment (FIGS. 9 to 11)
9A and 9B show a sixth embodiment of a control rod for a nuclear reactor according to the present invention, in which FIG. 9A is a front view showing a left half sheath cut away, and FIG. FIG. In the sixth embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

この第６の実施の形態の原子炉用制御棒９０は、図１８に示す原子炉用制御棒２１と基本的な構造を同一とするが、一体型中性子吸収要素９１であるハフニウム管２０のシース７に対向する面に前記第１、第２または第３の実施の形態のそれぞれの縦溝４２、５２または６２が形成された点と、上記ハフニウム管２０に形成されてスティフナ２２が挿通される貫通孔９３の大きさの点と、シース７及び上記ハフニウム管２０に第１の実施の形態と同様な重複通水孔９４が形成された点などが、前記原子炉用制御棒２１と異なる。   The reactor control rod 90 of the sixth embodiment has the same basic structure as the reactor control rod 21 shown in FIG. 18, but the sheath of the hafnium tube 20 that is an integral neutron absorbing element 91. 7 is formed in the hafnium tube 20 and the stiffener 22 is inserted through the surface where the vertical grooves 42, 52 or 62 of the first, second or third embodiment are formed. The reactor control rod 21 differs from the reactor control rod 21 in that the size of the through-hole 93 is different from that of the sheath 7 and the hafnium tube 20 in which an overlapping water-passing hole 94 similar to that of the first embodiment is formed.

つまり、原子炉用制御棒９０においては、制御棒挿抜方向に形成された複数枚（例えば４枚）の一体型中性子吸収要素９１のうち、挿入先端から１／４乃至３／４の範囲でハフニウム管２０の厚さがシース７の厚さよりも厚い制御棒挿入先端側に位置する２枚の一体型中性子吸収要素９１では、シース７に対向する面に、制御棒挿抜方向に延びる１本または複数本の縦溝４２、５２、６２が形成されている。   That is, in the control rod 90 for the reactor, hafnium is within a range from 1/4 to 3/4 from the insertion tip among a plurality of (for example, four) integrated neutron absorbing elements 91 formed in the control rod insertion / extraction direction. In the two integrated neutron absorbing elements 91 located on the control rod insertion tip side where the thickness of the tube 20 is thicker than the thickness of the sheath 7, one or a plurality of neutron absorbing elements 91 extending in the control rod insertion / extraction direction on the surface facing the sheath 7. Longitudinal grooves 42, 52, and 62 are formed.

また、一体型中性子吸収要素９１では、スティフナ２２が挿通する貫通孔９３が、ウイング２の側端６３側に位置する一体型中性子吸収要素９１のハフニウム管２０に形成されるが、このうち、上記制御棒挿入先端側に位置する一体型中性子吸収要素９１では、ハフニウム管２０に形成される貫通孔９３が制御棒挿抜方向に延びる長孔に形成される。この貫通孔９３の長手方向寸法は、当該一体型中性子吸収要素９１を先端構造体４に固定する固定部２７から離れるにしたがって順次大きく形成される。従って、この貫通孔９３に挿通されるスティフナ２２と当該貫通孔９３との間の孔間隙９５も、上記固定部２７から離れるにしたがって順次大きく形成される。図９（Ｂ）では、常温の初期状態が示されており、原子炉用制御棒９０の温度が上昇すると、ハフニウム管２０よりもシース７の方が熱膨張率が大きいため、スティフナ２２は、孔間隙９５の広い方向（図９（Ｂ）における下方）へ相対的に移動する。   Further, in the integrated neutron absorbing element 91, a through hole 93 through which the stiffener 22 is inserted is formed in the hafnium tube 20 of the integrated neutron absorbing element 91 located on the side end 63 side of the wing 2. In the integrated neutron absorbing element 91 located on the control rod insertion tip side, a through hole 93 formed in the hafnium tube 20 is formed as a long hole extending in the control rod insertion / extraction direction. The dimension in the longitudinal direction of the through-hole 93 is gradually increased as the distance from the fixing portion 27 for fixing the integrated neutron absorbing element 91 to the tip structure 4 is increased. Accordingly, the hole gap 95 between the stiffener 22 inserted through the through hole 93 and the through hole 93 is also formed to increase gradually as the distance from the fixed portion 27 increases. FIG. 9B shows an initial state at room temperature. When the temperature of the nuclear reactor control rod 90 rises, the sheath 7 has a higher coefficient of thermal expansion than the hafnium tube 20, so the stiffener 22 is It moves relatively in the wide direction of the hole gap 95 (downward in FIG. 9B).

更に、上記スティフナ２２は、前記実施の形態の保持部材３２の軸部３２Ｂにおける大径部３８と同様に機能するシース非挿通部９６（図１１）と、小径部３９と同様に機能するシース挿通部９７（図１１）とを有して構成される。シース非挿通部９６は、一体型中性子吸収要素９１におけるハフニウム管２０の厚さ方向寸法Ｘよりも所定寸法δだけ長く形成されて、対向するシース７間の間隔を上記寸法（Ｘ+δ）に保持する。また、シース挿通部９７は、シース７の厚さと略等しく形成されて、このシース７に形成された装着孔９８に挿通され、先端部がシース７の外面に溶着される。   Further, the stiffener 22 includes a sheath non-insertion portion 96 (FIG. 11) that functions in the same manner as the large-diameter portion 38 in the shaft portion 32 </ b> B of the holding member 32 of the above embodiment, and a sheath insertion that functions in the same manner as the small-diameter portion 39. Part 97 (FIG. 11). The sheath non-insertion portion 96 is formed longer than the dimension X in the thickness direction of the hafnium tube 20 in the integrated neutron absorption element 91 by a predetermined dimension δ, and the distance between the facing sheaths 7 is set to the dimension (X + δ). Hold. The sheath insertion portion 97 is formed to be substantially equal to the thickness of the sheath 7, and is inserted into the mounting hole 98 formed in the sheath 7, and the distal end portion is welded to the outer surface of the sheath 7.

これらのシース非挿通部９６、シース挿通部９７は、例えば四角柱形状に形成されたものであり、断面四角形の対角線がシース挿通部９７よりもシース非挿通部９６の方が大きな寸法に設定されている。これにより、シース非挿通部９６とシース挿通部９７との間に、前記段差部４０と同様な段差部９９が形成される。シース挿通部９７の先端部がシース７の外面に固着され、上記段差部９９がシース７の内面に当接することで、対向するシース７間の間隔が、ハフニウム管２０の厚さ方向寸法Ｘよりも所定寸法δだけ大きく設定される。これにより、シース７とハフニウム管２０とが相対移動可能に設けられる。   The sheath non-insertion portion 96 and the sheath insertion portion 97 are formed in, for example, a quadrangular prism shape, and the diagonal of the square cross section is set to be larger in the dimension of the sheath non-insertion portion 96 than the sheath insertion portion 97. ing. As a result, a step portion 99 similar to the step portion 40 is formed between the sheath non-insertion portion 96 and the sheath insertion portion 97. The distal end portion of the sheath insertion portion 97 is fixed to the outer surface of the sheath 7, and the stepped portion 99 abuts against the inner surface of the sheath 7, so that the distance between the facing sheaths 7 is greater than the thickness direction dimension X of the hafnium tube 20. Is also set larger by a predetermined dimension δ. Thereby, the sheath 7 and the hafnium tube 20 are provided so as to be relatively movable.

上記制御棒挿入先端側に位置する一体型中性子吸収要素９１では、重複通水孔９４は、シース７に形成されたシース孔９Ｂ１と、ハフニウム管２０に形成されたハフニウム孔９Ｂ３とが重ね合わされて貫通して構成される。このうち、ハフニウム孔９Ｂ３は、制御棒挿抜方向に延びる長孔に形成される。このハフニウム孔９Ｂ３の長手方向寸法は、上記一体型中性子吸収要素９１を先端構造材４に固定する固定部２７から離れるにしたがって順次大きく形成されている。原子炉用制御棒９０の温度が上昇したとき、ハフニウム管２０よりもシース７の方が熱膨張量が大きいため、シース孔９Ｂ１がハフニウム孔９Ｂ３に対し固定部２７から離れる方向に相対移動して、重複通水孔９Ｂの孔面積が略一定に維持される。   In the integrated neutron absorption element 91 located on the control rod insertion tip side, the overlapping water passage hole 94 is formed by overlapping the sheath hole 9B1 formed in the sheath 7 and the hafnium hole 9B3 formed in the hafnium tube 20. Configured to penetrate. Among these, the hafnium hole 9B3 is formed as a long hole extending in the control rod insertion / extraction direction. The longitudinal dimension of the hafnium hole 9B3 is gradually increased as the distance from the fixing portion 27 for fixing the integrated neutron absorbing element 91 to the tip structural member 4 is increased. When the temperature of the nuclear reactor control rod 90 rises, the sheath 7 has a larger amount of thermal expansion than the hafnium tube 20, so that the sheath hole 9B1 moves relative to the hafnium hole 9B3 in the direction away from the fixed portion 27. The hole area of the overlapping water passage hole 9B is maintained substantially constant.

尚、スティフナ２２が挿通する貫通孔９３と重複通水孔９４のハフニウム孔９Ｂ３とは、一体型中性子吸収要素９１のうち、制御棒挿入先端側に位置する一体型中性子吸収要素９１を除く、制御棒挿入末端側に位置する一体型中性子吸収要素９１においても、同様に、当該一体型中性子吸収要素９１を末端構造材５に固定する固定部２７から離れるにしたがって順次大きく形成されてもよい。また、図９（Ｂ）には、シース孔９Ｂ１を便宜上示している。   The through-hole 93 through which the stiffener 22 is inserted and the hafnium hole 9B3 of the overlapping water-passing hole 94 are controlled by removing the integrated neutron absorbing element 91 located on the control rod insertion tip side from the integrated neutron absorbing element 91. Similarly, the integrated neutron absorbing element 91 located on the rod insertion end side may be formed so as to gradually increase as the distance from the fixing portion 27 that fixes the integrated neutron absorbing element 91 to the terminal structure material 5 is increased. FIG. 9B shows the sheath hole 9B1 for convenience.

以上のように構成されたことから、本実施の形態によれば、制御棒挿入先端側に位置する一体型中性子吸収要素９１のハフニウム管２０に縦溝４２、５２、６２が形成され、また、上記一体型中性子吸収要素９１のハフニウム管２０に形成されてスティフナ２２が挿通する制御棒挿抜方向に延びる貫通孔９３が長孔に形成され、更に、重複通水孔９Ｂのハフニウム孔９Ｂ３が制御棒挿抜方向に延びる長孔に形成され、また、上記スティフナ２２がシース非挿通部９６とシース挿通部９７とを有して構成されたことから、前記第１の実施の形態の効果（１）〜（５）と同様な効果を奏する。   Due to the above configuration, according to the present embodiment, the longitudinal grooves 42, 52, 62 are formed in the hafnium tube 20 of the integrated neutron absorption element 91 located on the control rod insertion tip side, and A through hole 93 formed in the hafnium tube 20 of the integrated neutron absorption element 91 and extending in the control rod insertion / removal direction through which the stiffener 22 is inserted is formed as a long hole, and further, the hafnium hole 9B3 of the overlapping water passage hole 9B is a control rod. Since the stiffener 22 is formed to have a long hole extending in the insertion / extraction direction and the sheath non-insertion portion 96 and the sheath insertion portion 97, the effects (1) to (1) of the first embodiment are used. The same effect as (5) is produced.

［Ｇ］第７の実施の形態（図１２）
図１２は、本発明に係る原子炉用制御棒の第７の実施の形態の主要部を示し、左半分のシースを切り欠いて示す正面図である。この第７の実施の形態において、前記第１の実施の形態と同様な部分は、同一の符号を付すことにより説明を省略する。 [G] Seventh embodiment (FIG. 12)
FIG. 12 is a front view showing the main part of the seventh embodiment of the control rod for a nuclear reactor according to the present invention, with the left half sheath cut away. In the seventh embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

この原子炉用制御棒１００は、いわゆるハイブリッド型制御棒であり、横断面が深いＵ字状をなすシース７内に、中性子吸収材である板状のハフニウム板１０１及び１０２と、複数本の中性子吸収棒１０３とが収容されて構成される。ハフニウム板１０１及び１０２は、シース７内で、原子炉用制御棒１００の少なくとも挿入先端側部分に設置されたものであり、ハフニウム板１０１がシース７内の上記挿入先端から一定長さ（例えば１５〜３０ｃｍ）の部分に設置される。ハフニウム板１０２は、ウイング２の側端側部分に長尺状に配置される。   This nuclear reactor control rod 100 is a so-called hybrid control rod, and has a plate-shaped hafnium plate 101 and 102 as a neutron absorber and a plurality of neutrons in a sheath 7 having a U-shaped cross section. The absorption rod 103 is accommodated and configured. The hafnium plates 101 and 102 are installed at least on the insertion tip side portion of the reactor control rod 100 in the sheath 7, and the hafnium plate 101 has a certain length (for example, 15) from the insertion tip in the sheath 7. ˜30 cm). The hafnium plate 102 is disposed in a long shape on the side end side portion of the wing 2.

上記中性子吸収棒１０３は、シース７内において、ハフニウム板１０１及び１０２が配置された部分を除く残りの部分に設置される。この中性子吸収棒１０３は、ステンレス鋼（ＳＵＳ）製の被覆管内にボロンカーバイト（Ｂ４Ｃ）などの中性子吸収物質が充填されて構成される。 The neutron absorber rod 103 is installed in the remaining portion of the sheath 7 except for the portion where the hafnium plates 101 and 102 are disposed. The neutron absorber rod 103 is configured by filling a stainless steel (SUS) cladding tube with a neutron absorbing material such as boron carbide (B 4 C).

このような原子炉用制御棒１００において、上記ハフニウム板１０１及び１０２におけるシース７と対向する面に、制御棒挿抜方向と平行な方向に延びる、前記第１、第２または第３の実施の形態のそれぞれの縦溝４２、５２または６２が形成されている。   In such a control rod 100 for a nuclear reactor, the first, second or third embodiment extends in a direction parallel to the control rod insertion / extraction direction on the surface of the hafnium plates 101 and 102 facing the sheath 7. Each vertical groove 42, 52 or 62 is formed.

したがって、本実施の形態においても、ハフニウム板１０１及び１０２に縦溝４２、５２または６２が形成されたことから、原子炉運転時において、これらのハフニウム板１０１、１０２の通水性及び冷却性等が高まるなど、前記第１の実施の形態の効果（１）と同様な効果を奏する。   Therefore, also in the present embodiment, since the longitudinal grooves 42, 52 or 62 are formed in the hafnium plates 101 and 102, the water permeability and cooling performance of the hafnium plates 101 and 102 are improved during the reactor operation. The effect similar to the effect (1) of the first embodiment is obtained.

本発明に係る原子炉用制御棒の第１の実施の形態における主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図。The front view which is a principal part in 1st Embodiment of the control rod for reactors which concerns on this invention, and cuts off the front sheath and shows an integrated neutron absorption element. （Ａ）、（Ｂ）、（Ｃ）、（Ｄ）は、図１のIIＡ‐IIＡ線、IIＢ‐IIＢ線、IIＣ‐IIＣ線、IIＤ‐IIＤ線にそれぞれ沿う断面図。(A), (B), (C), (D) is sectional drawing which follows the IIA-IIA line of FIG. 1, the IIB-IIB line, the IIC-IIC line, and the IID-IID line, respectively. 図２（Ｂ）を拡大して示す断面図。Sectional drawing which expands and shows FIG. 2 (B). 本発明に係る原子炉用制御棒の第２の実施の形態の主要部を示し、（Ａ）は図４（Ｂ）のIVＡ‐IVＡ線に沿う断面図、（Ｂ）は図４(Ａ)のIVＢ‐IVＢ線に沿う断面図。The main part of 2nd Embodiment of the control rod for reactors which concerns on this invention is shown, (A) is sectional drawing which follows the IVA-IVA line | wire of FIG. 4 (B), (B) is FIG. 4 (A). Sectional drawing which follows the IVB-IVB line | wire. 図４（Ａ）の一部を拡大して示す断面図。Sectional drawing which expands and shows a part of FIG. 4 (A). 本発明に係る原子炉用制御棒の第３の実施の形態の主要部を示し、（Ａ）は図６（Ｂ）のVIＡ‐VIＡ線に沿う断面図、（Ｂ）は図６(Ａ)のVIＢ‐VIＢ線に沿う断面図。The main part of 3rd Embodiment of the control rod for reactors which concerns on this invention is shown, (A) is sectional drawing which follows the VIA-VIA line | wire of FIG. 6 (B), (B) is FIG. 6 (A). Sectional drawing which follows the VIB-VIB line. 本発明に係る原子炉用制御棒の第４の実施の形態の主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図。The front view which is a principal part of 4th Embodiment of the control rod for reactors which concerns on this invention, and notches the sheath of the front, and shows an integrated neutron absorption element. 本発明に係る原子炉用制御棒の第５の実施の形態の主要部であり、前面のシースを切り欠いて一体型中性子吸収要素を示す正面図。The front view which is a principal part of 5th Embodiment of the control rod for reactors which concerns on this invention, and notches the sheath of the front, and shows an integrated neutron absorption element. 本発明に係る原子炉用制御棒の第６の実施の形態を示し、（Ａ）は左半分のシースを切り欠いて示す正面図、（Ｂ）は図９（Ａ）の一部拡大図。The 6th Embodiment of the control rod for nuclear reactors which concerns on this invention is shown, (A) is the front view which notches and shows the sheath of the left half, (B) is a partially expanded view of FIG. 9 (A). 図９（Ｂ）のX−X線に沿う断面図。Sectional drawing which follows the XX line of FIG.9 (B). 図９（Ｂ）のスティフナの配置箇所を拡大して示す断面図。Sectional drawing which expands and shows the arrangement | positioning location of the stiffener of FIG.9 (B). 本発明に係る原子炉用制御棒の第７の実施の形態の主要部を示し、左半分のシースを切り欠いて示す正面図。The front view which shows the principal part of 7th Embodiment of the control rod for reactors which concerns on this invention, and notches and shows the sheath of the left half. 実用化された従来の原子炉用制御棒の概要を示し、（Ａ）は一部を切り欠いて示す斜視図、（Ｂ）は図１３（Ａ）の一ウイングを示す横断面図、（Ｃ）は図１３（Ｂ）における保持部材を示す斜視図An outline of a conventional nuclear reactor control rod that has been put into practical use is shown, (A) is a perspective view with a part cut away, (B) is a cross-sectional view showing one wing of FIG. 13 (A), (C ) Is a perspective view showing the holding member in FIG. （Ａ）は図１３（Ａ）の原子炉用制御棒において前面のシースを切り欠いて示す正面図、（Ｂ）は、図１４（Ａ）の中性子吸収材であるハフニウム板の厚さ分布及び反応度価値を示す図。FIG. 13A is a front view of the reactor control rod of FIG. 13A with the front sheath cut away, and FIG. 14B is the thickness distribution of the hafnium plate that is the neutron absorber of FIG. The figure which shows the reactivity value. 従来の原子炉用制御棒の中性子吸収材であるハフニウム板の厚さ分布を示す図。The figure which shows thickness distribution of the hafnium plate which is a neutron absorber of the conventional nuclear reactor control rod. （Ａ）は、図１４（Ａ）の要部拡大正面図、（Ｂ）は、図１６（Ａ）の一対のハフニウム板（一体型中性子吸収要素）を拡大して示す正面図、（Ｃ）は、図１６（Ｂ）のXVI‐XVI線に沿う断面図。14A is an enlarged front view of the main part of FIG. 14A, FIG. 14B is an enlarged front view of the pair of hafnium plates (integrated neutron absorbing elements) in FIG. 16A, and FIG. FIG. 17 is a cross-sectional view taken along line XVI-XVI in FIG. （Ａ）は図１３（Ａ）の原子炉用制御棒の一ウイングを拡大して示す正面図であり、（Ｂ）、（Ｃ）、（Ｄ）は、図１７（Ａ）のXVIIＢ‐XVIIＢ線、XVIIＣ‐XVIIＣ線、XVIIＤ‐XVIIＤ線にそれぞれ沿う断面図である。(A) is an enlarged front view showing one wing of the nuclear reactor control rod in FIG. 13 (A), and (B), (C), and (D) are XVIIB-XVIIB in FIG. 17 (A). It is sectional drawing which each follows a line, a XVIIC-XVIIC line, and a XVIID-XVIID line. 図１３とは異なる従来の他の原子炉用制御棒を示し、（Ａ）は左半分のシースを切り欠いて示す正面図、（Ｂ）は図１８（Ａ）の中性子吸収材の厚さ分布を示す図、（Ｃ）は図１８（Ａ）のXVIII‐XVIII線に沿う断面図。13 shows another conventional control rod for a nuclear reactor different from FIG. 13, (A) is a front view showing the left half sheath cut away, and (B) is the thickness distribution of the neutron absorber shown in FIG. 18 (A). FIG. 18C is a cross-sectional view taken along line XVIII-XVIII in FIG.

符号の説明Explanation of symbols

２ ウイング
４ 先端構造材
５ 先端構造材
６ 中央構造材
７ シース
９ 通水孔
９Ａ シース通水孔
９Ｂ 重複通水孔
９Ｂ１ シース孔
９Ｂ２、９Ｂ３ ハフニウム孔
１０ ハフニウム板
２０ ハフニウム管
２２ スティフナ（保持部材）
２７ 固定部
３０ 原子炉用制御棒
３１ 一体型中性子吸収要素
３２ 保持部材
３２Ａ スペーサ部
３２Ｂ 軸部
３４ 貫通孔
３７ 孔間隙
３８ 大径部
３９ 小径部
５０ 原子炉用制御棒
５１ 一体型中性子吸収要素
５２ 縦溝
６０ 原子炉用制御棒
６１ 一体型中性子吸収要素
６２ 縦溝
６３ 側端
７０ 原子炉用制御棒
７１ 一体型中性子吸収要素
７２ 横溝
８０ 原子炉用制御棒
８１ 一体型中性子吸収要素
８２、８３ 横溝
８４ 溝通水孔
９０ 原子炉用制御棒
９１ 一体型中性子吸収要素
９３ 貫通孔
９４ 重複通水孔
９６ シース非挿通部
９７ シース挿通部
１００ 原子炉用制御棒
１０１、１０２ ハフニウム板
１０３ 中性子吸収棒
δ 所定寸法
Ｍ１、Ｍ２、Ｎ 肉厚 2 Wing 4 Tip structure material 5 Tip structure material 6 Center structure material 7 Sheath 9 Water passage hole 9A Sheath water passage hole 9B Overlapping water passage hole 9B1 Sheath holes 9B2, 9B3 Hafnium hole 10 Hafnium plate 20 Hafnium tube 22 Stiffener (holding member)
27 Fixed part 30 Reactor control rod 31 Integrated neutron absorption element 32 Holding member 32A Spacer part 32B Shaft part 34 Through hole 37 Hole gap 38 Large diameter part 39 Small diameter part 50 Reactor control rod 51 Integrated neutron absorption element 52 Vertical groove 60 Reactor control rod 61 Integrated neutron absorption element 62 Vertical groove 63 Side end 70 Reactor control rod 71 Integrated neutron absorption element 72 Horizontal groove 80 Reactor control rod 81 Integrated neutron absorption elements 82, 83 Horizontal groove 84 Groove water passage 90 Reactor control rod 91 Integrated neutron absorption element 93 Through hole 94 Overlapping water hole 96 Sheath non-insertion portion 97 Sheath insertion portion 100 Reactor control rod 101, 102 Hafnium plate 103 Neutron absorption rod δ Predetermined Dimensions M1, M2, N Wall thickness

Claims (4)

横断面がＵ字状をなす長尺のシースの開口部を、中央構造材に固着して複数のウイングを構成し、このウイングの炉心挿入方向先端側に先端構造材を、挿入末端側に末端構造材をそれぞれ固着すると共に、板状のハフニウムを主な中性子吸収材とする複数の一体型中性子吸収要素を、前記シース内に当該シースの長手方向に列状に収容する原子炉用制御棒において、
制御棒挿抜方向に配列された複数の前記一体型中性子吸収要素のうち、挿入先端から１／４乃至３／４の範囲で、前記中性子吸収材の厚さが前記シースの厚さよりも厚い制御棒挿入先端側に位置する一体型中性子吸収要素では、当該一体型中性子吸収要素の前記中性子吸収材における前記シースと対向する面に、制御棒挿抜方向に略平行な縦溝が形成され、
この縦溝は、制御棒挿入先端方向において前記中央構造材から前記ウイング側端方向へ向かって傾斜し、この縦溝の方向が、前記一体型中性子吸収要素の対向する複数枚の前記中性子吸収材相互間で略平行に設けられたことを特徴とする原子炉用制御棒。 A long sheath opening having a U-shaped cross section is fixed to the central structural member to form a plurality of wings. In a control rod for a nuclear reactor in which a plurality of integrated neutron absorbing elements each having a structural material fixed thereto and having plate-like hafnium as a main neutron absorber are accommodated in the sheath in a row in the longitudinal direction of the sheath. ,
Among the plurality of integrated neutron absorption elements arranged in the control rod insertion / extraction direction, the control rod has a thickness of the neutron absorber thicker than the thickness of the sheath in a range of 1/4 to 3/4 from the insertion tip. In the integrated neutron absorbing element located on the insertion tip side, a longitudinal groove substantially parallel to the control rod insertion / extraction direction is formed on the surface of the integrated neutron absorbing element facing the sheath in the neutron absorber ,
The longitudinal groove is inclined from the central structural member toward the wing side end direction in the control rod insertion tip direction, and the direction of the longitudinal groove is a plurality of the neutron absorbers facing the integrated neutron absorbing element. A control rod for a nuclear reactor , which is provided substantially parallel to each other . 前記縦溝の深さは、当該縦溝の底から中性子吸収材の反対側の面までの当該中性子吸収材の肉厚が、シースの肉厚以上となる範囲で設定されたことを特徴とする請求項１に記載の原子炉用制御棒。 The depth of the longitudinal groove is set in a range in which the thickness of the neutron absorber from the bottom of the longitudinal groove to the opposite surface of the neutron absorber is equal to or greater than the thickness of the sheath. The nuclear reactor control rod according to claim 1. 前記一体型中性子吸収要素は、当該一体型中性子吸収要素の中性子吸収材に形成された貫通孔に挿通されてシースに固着される軸部と、当該一体型中性子吸収要素の前記中性子吸収材の間隔を保持するスペーサ部とを備えた保持部材により荷重が保持され、
この保持部材の前記軸部は、スペーサ部側から前記中性子吸収材の厚さよりも所定寸法長く形成されて、前記中性子吸収材の厚さ方向の微妙な移動を可能とする大径部と、前記シースの厚さと略等しく形成されて当該シースに挿通される小径部とを備え、当該小径部の先端が前記シースの外面に固着されて、当該シースと前記中性子吸収材とが制御棒挿抜方向に相対移動可能に設けられたことを特徴とする請求項１または２に記載の原子炉用制御棒。 The integrated neutron absorbing element includes a shaft portion inserted into a through hole formed in the neutron absorbing material of the integrated neutron absorbing element and fixed to the sheath, and an interval between the neutron absorbing material of the integrated neutron absorbing element. The load is held by a holding member having a spacer portion for holding
The shaft portion of the holding member is formed longer than the thickness of the neutron absorber from the spacer portion side, and has a large diameter portion that enables a delicate movement in the thickness direction of the neutron absorber, and A small-diameter portion formed substantially equal to the thickness of the sheath and inserted through the sheath, the distal end of the small-diameter portion being fixed to the outer surface of the sheath, and the sheath and the neutron absorber in the control rod insertion / extraction direction reactor control rod according to claim 1 or 2, characterized in that provided movable relative. 前記一体型中性子吸収要素は、当該一体型中性子吸収要素の中性子吸収材に形成された貫通孔に挿通されてシースに固着される軸部と、当該一体型中性子吸収要素の前記中性子吸収材の間隔を保持するスペーサ部とを備えた保持部材により荷重が保持され、
制御棒挿入先端側に位置する前記各一体型中性子吸収要素では、挿入末端側または挿入先端側のいずれか一方における一対の保持部材の軸部が挿通する貫通孔が、制御棒挿抜方向に延びる長孔であることを特徴とする請求項１乃至３のいずれかに記載の原子炉用制御棒。 The integrated neutron absorbing element includes a shaft portion inserted into a through hole formed in the neutron absorbing material of the integrated neutron absorbing element and fixed to the sheath, and an interval between the neutron absorbing material of the integrated neutron absorbing element. The load is held by a holding member having a spacer portion for holding
In each of the integrated neutron absorbing elements located on the control rod insertion tip side, the through holes through which the shaft portions of the pair of holding members on either the insertion end side or the insertion tip side are inserted extend in the control rod insertion / extraction direction. The reactor control rod according to any one of claims 1 to 3 , wherein the control rod is a hole.
JP2006233080A 2006-08-30 2006-08-30 Reactor control rod Expired - Fee Related JP4991213B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006233080A JP4991213B2 (en) 2006-08-30 2006-08-30 Reactor control rod

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2006233080A JP4991213B2 (en) 2006-08-30 2006-08-30 Reactor control rod

Publications (2)

Publication Number Publication Date
JP2008058053A JP2008058053A (en) 2008-03-13
JP4991213B2 true JP4991213B2 (en) 2012-08-01

Family

ID=39240976

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2006233080A Expired - Fee Related JP4991213B2 (en) 2006-08-30 2006-08-30 Reactor control rod

Country Status (1)

Country Link
JP (1) JP4991213B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010243331A (en) * 2009-04-06 2010-10-28 Toshiba Corp Control rod for nuclear reactor
JP5355201B2 (en) * 2009-04-22 2013-11-27 株式会社東芝 Reactor control rod
JP6625501B2 (en) * 2016-08-23 2019-12-25 日立Ｇｅニュークリア・エナジー株式会社 Control rod and boiling water reactor equipped therewith

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2505829B2 (en) * 1987-11-19 1996-06-12 株式会社東芝 Control rod for nuclear reactor
JPH036493A (en) * 1989-06-05 1991-01-11 Toshiba Corp Reactor control rod
JPH0990080A (en) * 1995-09-27 1997-04-04 Toshiba Corp Control rod for reactor
JPH10104382A (en) * 1996-08-08 1998-04-24 Toshiba Corp Control rod for reactor
JPH11118972A (en) * 1997-10-16 1999-04-30 Toshiba Corp Control rod for reactor and its manufacturing method

Also Published As

Publication number Publication date
JP2008058053A (en) 2008-03-13

Similar Documents

Publication Publication Date Title
JPH02285286A (en) Fuel assembly and fuel spacer
JP4991213B2 (en) Reactor control rod
JPH0560889A (en) Fuel assembly for light-water nuclear reactor
KR100415149B1 (en) Double strip mixing grid for a nuclear fuel assembly
US9014325B2 (en) Nuclear fuel assembly tie plate, upper nozzle and nuclear fuel assembly comprising such a tie plate
JP2009058447A (en) Control rod for reactor
US6714619B2 (en) Spacer grid with double deflected vanes for nuclear fuel assemblies
JP4369493B2 (en) Control rod
US8761331B2 (en) Control rod for boiling water reactor
JP2008164533A (en) Control rod for reactor
JP5308744B2 (en) Control rod
JP5376782B2 (en) Reactor control rod and manufacturing method thereof
JP5269327B2 (en) Reactor control rod
JP2009042006A (en) Control rod for boiling water reactor
JP2008057999A (en) Control rod for nuclear reactor and its integrity prediction method
US9053825B2 (en) Fuel assembly
JP2009128349A (en) Control rod
JP2523694B2 (en) Fuel assembly
KR101071286B1 (en) Spacer grid inserted upward/downward movable spring supportplate to support fuel rods at interior grid intersection regions
JP5075357B2 (en) Reactor control rod
JP2012202877A (en) Control rod for boiling-water reactor and manufacturing method thereof
JP3310268B2 (en) Channel box
JPS63289486A (en) Control rod for nuclear reactor
JP6625501B2 (en) Control rod and boiling water reactor equipped therewith
CN100573734C (en) The fuel stringer assembly that is used for nuclear reactor

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20081218

RD01 Notification of change of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7421

Effective date: 20111214

RD01 Notification of change of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7421

Effective date: 20120118

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120131

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120315

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

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120410

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120507

R151 Written notification of patent or utility model registration

Ref document number: 4991213

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150511

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees