Japan Nuclear Fuel Co., Ltd.

Hitachi, Ltd.

Makoto Udaka

Yasuo Nakagawa

Toshimitsu Hamada

Hiroshi Makihira

Kenich Katsumizu

Takashi Sekine

Takasi Sekine

Keiji Suzuki

Kenji Umezu

Teruaki Mishima

Tatsumo Yoshida

Kojiro Komuro

Keiichi Aoki

An apparatus for automatically loading one or more kinds of nuclear fuel pellets in fuel cladding tubes for producing nuclear fuel rods comprises at least one pellet transporting tray transferred from a tray stacking unit and provided with a plurality of grooves on which the fuel pellets are mounted, at least one pellet aligning tray provided with a groove selectively connected with one of the grooves of the pellet transporting tray at one end of the aligning tray, and a fuel cladding tube supporting device located in the vicinity of the other end of the aligning tray and adapted to support a number of fuel cladding tubes so that a selected one fuel cladding tube is operatively connected to the aligning tray. The fuel pellets are transferred from the transporting tray into the aligning tray by means of a pushing device and the row of the pellets transferred on the groove of the aligning tray is moved forwardly until it abuts against a stopping mechanism located in association with the aligning tray. The row of pellets is separated at the predetermined portion by a row length defining device so that the separated forward portion of the pellet row has a predetermined length including allowable common difference and then the separated pellet row is loaded into the cladding tube to produce the fuel rod. During these operations the weight of the fuel pellets to be loaded is properly measured.

Apparatus for automatically loading nuclear fuel pellets

A fuel assembly has a plurality of fuel rods arranged and held in parallel with one another in the cells of spacer assemblies arranged at suitable intervals. During the assemblying and transportation of the fuel assembly, flexible sleeves are inserted in respective cells such as to separate the fuel rods from parts provided on the walls of the cells, thereby protecting the fuel rod surfaces against any damage and scratch which may otherwise be caused due to interference between the fuel rod surface and the parts provided on the walls of the cell.

Method of and arrangement for protecting nuclear fuel assembly

An apparatus for inspecting the outer peripheral surface of a cylindrical object is disclosed, in which the light in slit form is radiated on the surface of an object such as a nuclear fuel pellet at an angle thereto, the light regularly reflected on the surface is detected by a detector, the detected image signal is quantized at threshold values higher and lower than an average level, and the binary signals are used to detect surface losses separately from an unground part and a metal inclusion as a first detection process. The diffused light is radiated onto the surface of the nuclear fuel pellet at an angle thereto, parallel light rays are radiated onto the surface from the direction perpendicular thereto, the light reflected from the surface of the object is detected by a detector from the direction perpendicular to the surface, the detected image signal is quantized at a threshold level lower than an average level of the image signal for the normal surface, and the binary signal is used to detect, as a second detection process, a crack and a pit separately from a chip, said crack, pit or chip included in surface missing defects detected in said first detection process. The surface defects of the nuclear fuel pellet or the like are thus detected by separating them into at least three types including a chip, an unground part and a metal inclusion, and a crack and a pit.

Method and apparatus for appearance inspection

A surface defect inspection system comprises an image pick-up device for picking up an image by sequentially scanning the surface of an object two-dimensionally, a threshold circuit for quantizing the image signal produced from the image pick-up device as a binary code, a pattern feature extracting device for making calculations for extracting the features of image patterns from the quantized signal in synchronism with the scanning, and for temporarily storing the result of the calculations, a pattern region end decision device for deciding that individual pattern regions have ended in one direction, and a defect decision device for reading out from the pattern feature extracting device the result of the calculations on the pattern features corresponding to the positions each of the patterns in the direction perpendicular to the one direction each time of the decision that each pattern region has ended, so that the feature of each pattern scanned is compared with a predetermined reference, thus deciding and an indication of producing the presence or absence of a defect.

Surface defect inspection system

Growing community of inventors

Yokosuka, Japan

Makoto Udaka