Hitachi, Ltd.

Mitsubishi Nuclear Fuel Co., Ltd.

Masashi Yoshida

Akihiro Kato

Katsunori Ohuchi

Shuji Yamazaki

Jyunichi Matsuno

Akira Shimizu

Takashi Yoshida

Isao Shimizu

Yasuhiro Matsuda

Hideyuki Kawase

Katsumi Watanabe

Takao Terayama

Masataka Kawauchi

Seii Miyakawa

Junichi Oyama

Hajime Yokota

Kazunori Iijima

Yasuo Iino

Hideki Tanaka

Kazuo Honma

Toshihiko Gotoh

Satoshi Kawamura

Fumio Takeda

Noboru Katohno

Masao Okayama

Seiji Okunomiya

Tatsuya Shigemura

Akio Sando

Katsuya Sato

Taichi Koiwai

Nobuo Miwa

Koutarou Tanno

Mitsuji Aman

Tadashi Shinoda

Makoto Shiraki

Akira Kawauchi

An apparatus is presented for removing the inner and outer keys from a support grid of a fuel assembly automatically or by mechanical methods. The apparatus removes a line of keys from a loaded assembly inserted into a grid through an opening section of the grid to deflect the springs. Both ends of the keys are engaged with the engaging members, and one set of keys are rotated in one direction while the other set of keys are rotated in the opposite direction. The springs are then released to press on the fuel rods firmly in place between the springs and the dimples in the grid cell. The keys are removed from the grid by clamping or holding the keys and moving the keys together with the clamping/holding device in the key axis direction by operating the driving device until the keys are removed completely from the grid.

Apparatus for removing keys from support grid

A key member, a method for insertion and/or removal of the fuel rods in a nuclear fuel assembly using the key member and a method of disassembling the nuclear fuel assembly using the same key member are disclosed. The key member has first projections and second projections formed on the opposite faces of an elongated key body. In the insertion or removal of the fuel rods or in the disassembling the nuclear fuel assembly, the key member is inserted into the grid and rotated to bring the first projections and the second projections into engagement with the straps of the grids and the springs on the straps to thereby the springs are deflected in a direction away from the dimples opposing to the springs. In this situation, the insertion and removal of the fuel rods can be carried out. Further, in disassembling the nuclear fuel assembly, space required for inserting the key member into the grids may be ensured by subjecting prescribed portions of control rod-guide pipes and instrumentation pipes to cutting work and bulging the cut ends to move the cut end away from that of the opposing cut ends of the cut piece. The space may be formed by removing the control rod-guide pipes and instrumentation pipes after having formed slits in the pipes.

Method for insertion or removal of fuel rods into or from a grid of a

A thermal printer of the type printing an image on a printing paper wound in the form of a roll. Curling of the printing paper wound in the roll form occurs when the thermal printer is placed in its standby mode over more than a predetermined period of time while the printing paper is held between a platen roller and a thermal head. In order to prevent curling of the printing paper, the printing paper is rewound when the standby mode lasts over more than the predetermined period of time.

Thermal printer

The present invention presents an apparatus to facilitate the loading of specific fuel rods into the specific grid cells of the grids of a fuel assembly. The loading apparatus utilizes air-pressure operated loading cylinders to push out the specific fuel rods from a fuel rod magazine into the corresponding grid cells. The loading apparatus operates in conjunction with a series of fuel rod support rollers which provide support to the fuel rods, being charged into the grids, from the underside of the fuel rods to prevent sagging of the tip end, thus avoiding scraping against the straps of the grids when entering the grid cells, and causing potentially harmful surface scratches on the fuel rods.

Apparatus for assembling nuclear fuel assembly

The present invention relates to a pull-in rod type loader for loading fuel rods efficiently and conveniently from a fuel rod magazine to a fuel assembly. The control rod pipes and fuel rods are held in assigned grid cells, respectively termed pipe-cells and fuel-rod-cells, in each quadrant section of a grid. The control rod pipes are disposed in a quadrant so that the locations of the pipe-cells assigned for the guide pipes in one quadrant are symmetrical with respect to a central rotational axis of the apparatus. The grid cells and the pull-in loader are both aligned with respect to a central rotational axis. To load the fuel rods into the fuel assembly, only the pull-in rods need to be operated for every 90 degree rotation of the loader about the central axis, because the locations of the pull-in rods correspond exactly with the grid cells assigned to hold fuel rods. This type of loader does not require complex switching devices required in the conventional pull-in rod type of loaders, and the assembling operation can be carried out efficiently and quickly.

Assembling apparatus for nuclear fuel assembly

The present invention presents a method and an apparatus for assembling a fuel assembly which is free of surface damage on the fuel rod surfaces, and of distortions caused by residual stresses. Such problems are introduced by the method of inserting the fuel rods into the grids, and the sequence of attaching the control rod guiding pipes. In the conventional method, the guiding pipes are attached to the respective grids first and the fuel rods are inserted in the grids while the holding mechanisms (such as spring force against a dimple formed on the grid wall) are active. In the invented assembling method, the sprigs are deactivated first and then the fuel rods are inserted into the grids. Once the assembly is made firm with all the fuel rods in place and fixed firmly to the grids, the control rod guiding pipes are inserted into the grids and the pipes are fixed rigidly to the respective grids. By performing the assembling operation in the above sequence, slight shifting of the grids which occurs on fixing the pipes to the grids, during the conventional method, is prevented. The final assembly produced according to the invented method is free of surface damage and the overall quality of alignment of the assembly is excellent.

Apparatus for assembling a nuclear fuel assembly

A key member, a method for insertion and/or removal of the fuel rods in a nuclear fuel assembly using the key member and a method of disassembling the nuclear fuel assembly using the same key member are disclosed. The key member has first projections and second projections formed on the opposite faces of an elongated key body. In the insertion or removal of the fuel rods or in the disassembling the nuclear fuel assembly, the key member is inserted into the grid and rotated to bring the first projections and the second projections into engagement with the straps of the grids and the springs on the straps to thereby deflect the springs in a direction away from the dimples opposing the springs. In this situation, the insertion and removal of the fuel rods can be carried out. Further, in disassembling the nuclear fuel assembly, space required for inserting the key member into the grids may be ensured by subjecting prescribed portions of control rod-guide pipes and instrumentation pipes to cutting work and bulging the cut ends to move the cut end away from that of the opposing cut ends of the cut piece. The space may be formed by removing the control rod-guide pipes and instrumentation pipes after having formed slits in the pipes.

Key member for use in insertion or removal of a fuel rod of a nuclear

In the nuclear fuel assembly, a plurality of plate-shaped straps are assembled perpendicularly to each other into a grid shape so as to construct a supporting grid providing with a plurality of cells each of which inserts a nuclear fuel rod. A cell-size inspection device which inspects the size of each cell of the supporting grid is constructed by a base, a movable plate, a plurality of pin gauges and a sensor. The supporting grid is mounted on the base, while the movable plate is provided such that it can relatively move with respect to the base in a longitudinal direction of the cells. The pin gauges are provided on the movable plate such that they can freely slide along the longitudinal direction of the cells. When the movable plate is moved toward the supporting grid, each of the pin gauges is to be inserted into each of the cells. The sensor senses whether the pin gauge is relatively moved from the predetermined position of the movable plate. By simply inserting the pin gauge into the cell, it is possible to inspect the cell size with respect to a plenty of cells provided in the supporting grid. Thus, it is possible to inspect all of the cells in an extremely short time, which remarkably reduces the time and cost required for performing the inspection process on the nuclear fuel assembly.

Cell-size inspection device for nuclear fuel assembly

In a thermal transfer recording system, an ink paper cassette containing an ink paper having ink layers and an ink paper feed bobbin with the ink paper wound therearond, and further containing a take-up bobbin for taking up the ink paper fed from the feed bobbin, is used in conjunction with a recording paper, a platen roller, and a thermal head. The recording paper and the ink paper fed from the feed bobbin are disposed in a superimposed manner on the platen roller and are pressed toward the platen roller form the ink paper side and heated by the thermal head, thereby allowing ink to be transferred to the recording paper form the ink paper in accordance with information provided to the thermal head. A discrimination is made as to whether the ink paper cassette is a first ink paper cassette which contains a first ink paper having only ink layers, or a second ink paper cassette which contains a second ink paper having both a receiving layer and ink layers. If the ink paper cassette is judged to be the first ink paper cassette, a first recording paper having a receiving layer is selected, while if the ink paper cassette is judged to be the second ink paper cassette, a second recording paper not having a receiving layer is selected. Consequently, ink is transferred to the selected recording paper from the ink paper contained in the ink paper cassette.

Method and apparatus for thermal transfer recording and ink paper

An image printing method and system. Information of printing paper size, image size to be printed and printing position is inputted by user. On the basis of the information, a control circuit determines the number of data to be printed in the primary scanning direction as well as the number of data for blanks at both sides and additionally determines the number of lines for printing in the secondary scanning direction as well as line numbers for processing and succeeding blanks. In the primary scanning, the data to be printed is supplied to a thermal head together with the data for the blanks. In the secondary scanning, a printing sheet is transported idly for the blank portions. The thermal head is electrically energized in the printing portion for printing the image at a predetermined position on the printing paper.

Image printing method and system

A thermal transfer printer including a thermal head for generating heat in accordance with a desired print pattern, a platen having a surface for supporting an ink-sheet and paper, the ink-sheet and paper being pressed by the thermal head on the platen surface so that ink from the ink-sheet is transferred to the paper, a paper supply for storing and supplying paper, an ink-sheet supply and drive for storing and supplying an ink-sheet, the ink-sheet supply and drive driving the ink-sheet to move in accordance with the movement of the paper, a paper drive arranged between the platen and the paper supply, the paper drive driving the paper by the required length according to the position of the paper relative to the position of the platen, and a paper tension device for applying suitable tension to the paper at least between the platen and the paper drive so that the length by which the paper drive drives the paper is identical with the length by which the paper moves on the platen. Since the length by which the paper moves on the platen corresponds only to the length by which the paper drive drives the paper, the length by which the paper moves on the platen can be correctly controlled through the paper drive.

Thermal transfer printer

A heat sensitive transfer recording apparatus comprising a carrier such as a transfer film to which applied is a transfer material that may be heat transferred, a thermal head having a number of heater elements each producing heat in accordance with an image signal, and a platen roller rotatable in a forward direction or in a reverse direction. The carrier and a recording medium, such as a recording paper overlapped on the carrier, are delivered in the forward direction by the platen roller while being pressed by the thermal head, whereupon the image recording is carried out. Also, in case of multicolor overlap recording, the recording medium is delivered in the reverse direction under a pressure release condition of the thermal head by an assistant roller provided on a recording medium pay-out side with respect to the transfer position defined between the platen roller and the thermal head.

Heat sensitive transfer recording apparatus and method

In a control system for a thermal transfer color printer capable of color print, first and second sensors for detecting a printing paper are disposed before and after a platen roller for carrying the printing paper, so that when the printing paper is carried and detected by the first sensor, the printing paper is changed to a low speed and at the same time a thermal head is pressed against the printing paper through an ink film and when the printing paper is detected by the second sensor, the thermal head is supplied with a print signal for color printing.

Control system for a color printer

A recording apparatus of thermal transfer type includes a thermal head having a plurality of linearly-arrayed heat generating elements selectively generating heat in response to the application of a character and pattern information signal providing the thermal transfer energy, and a carrier having a coating of a thermally transferably recording material. A recording medium recording character and pattern information is disposed between the carrier and a platen roller to be transported by the platen roller. At the time of recording character and pattern information on the recording medium, the thermal transfer energy is applied to the heat generating elements corresponding to the character and pattern information signal while pressing the thermal head against the platen roller. During the recording, the thermal transfer energy is controlled to correspond to the required density tone of the character and pattern information to be recorded.

Thermal transfer recording apparatus

A thermal transfer color recording apparatus comprises a transfer sheet in which a plurality of color inks adapted to be thermally transferred are arrayed in a large number of regions, and a thermal head in which a plurality of heat generating elements adapted to generate heat in response to a picture recording signal are arrayed in the form of a line. The transfer sheet and a recording medium placed one over the other are conveyed in a forward or reverse direction by a platen roller while being depressed by the thermal head, and only the transfer sheet is conveyed without the depression of the thermal head. When the transfer sheet and the recording medium are conveyed in the forward or reverse direction by the platen roller while being depressed by the thermal head, the picture recording signal corresponding to each color is applied to the thermal head, whereby the plurality of colors of the inks are registered and transferred on the recording medium in succession and in single-color unit, and a color picture is recorded.

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Nakaminato, Japan

Masashi Yoshida