Abstract:
A fuel assembly for a nuclear reactor comprising a fuel cladding tube (11) of three-layer structure having an outer surface (16) in contact with reactor water of the nuclear reactor, an inner surface layer (14) in contact with the nuclear fuel, and an intermediate layer (15) interposed between the outer surface layer and the inner surface layer. the outer surface layer (16) is made of a Zr-based alloy containing Nb, Sn and Mo. The inner surface layer(14) is made of pure zirconium. The intermediate layer is made of a high ductility alloy which is higher in ductility than the outer surface layer (16) and is higher in strength than the inner surface layer(14).
Abstract:
La présente demande concerne un procédé de fabrication de tube pour gaine d'élément combustible, destiné à être utilisé dans un réacteur, en alliage à base de zirconium, comprenant plusieurs passes de laminage et de recuit successifs et une application de ce procédé à un alliage particulier. Elle est caractérisée en ce que l'étape finale du procédé est un traitement thermique d'homogénéisation de l'ensemble de l'élément en phase β par chauffage à une température comprise entre 950°C et 1250°C, suivi d'un refroidissement rapide à température ambiante.
Abstract:
Cladding tubes for containing nuclear fuel material utilizing zirconium base alloys containing from 0.1 to 0.6 weight per cent tin; from 0.07 to 0.24 weight per cent iron; about 0.05 to 0.15 weight per cent chromium; and up to 0.05 weight per cent nickel. The balance of the alloy is zirconium with incidental impurities. The levels of the incidental impurity, oxygen, is controlled to a level of less than 350 ppm. These alloys have been designed to minimize the adverse effects of pellet-clad interaction, when they are used as a liner bonded to the inside surface of water reactor nuclear fuel cladding.
Abstract:
The invention relates to a method of rendering clad, pellet (13) containing elements (11), such as displacement rods to be used in nuclear reactors, essentially immune from undesirable deformation of the cladding and from a formation of undesirable gaps therewithin. As a last step in the making of such element, its cladding Is heated to a temperature sufficient to reduce the yield strength of the cladding and, while at said temperature, has isostatic pressure radially applied thereto to cause collapse of the cladding onto the pellets therein. Preferably, heating of the cladding is carried out in an atmosphere resulting in the formation of a beneficial oxide coating on the outer surface of the cladding.
Abstract:
PURPOSE: A nuclear reactor is provided to improve cooling capability of a nuclear reactor external wall by preventing a film formed on a nuclear reactor external wall. CONSTITUTION: A container(100) is formed into a coupling structure of a hemispheric shape. The container accommodates core melt(110) in a lower part. A thermal shielding body(200) covers an external wall of the container. A nuclear reactor cavity(300) includes thermal shielding and the container. A partition wall(230) is formed from the thermal shielding body to the exterior wall of the container. The partition wall is formed with the exterior wall of the container. A guide wing(120) is formed between the partition walls.
Abstract:
본 발명은 핵연료봉용 피복재의 형성에의 사용에 적합한 지르코늄 합금 관재에 있어서 향상된 방사상 조직을 생성하는 방법에 관한 것이다. 본 발명은 관재 내에서 단일 피크 방사상 조직을 생성시키기 위해 관재형성의 최종 단계에서 기계적팽창 및 열처리 단계의 조합을 이용하여, 최종 관재에 대해 펠릿-피복-상호작용에 대한 향상된 내성을 부여하게된다. 바람직하게는 관재는 최종지름의 약 10 내지 20 이하 내의 지름으로 가공되고, 어니일링되고, 약 10 내지 20