Mitsubishi Heavy Industries Limited

Asahi Kogaku Kogyo Kabushiki Kaisha

Nobuyuki Hori

Takahiro Ota

Takaharu Maeguchi

Takeshi Yamamoto

Naoki Ogawa

Yukio Michishita

Tadaaki Suda

Ryuichi Narita

Koji Okimura

Hideshi Sakashita

Tomochika Hamamoto

Tsuyoshi Nishimura

Hiroshi Kanasaki

Yukihide Shimazu

Tomoshige Takata

Kazuya Tsutsumi

Hiroyuki Mizuma

Kazuhiro Yasumoto

Moritatsu Nishimura

Harutaka Suzuki

Yuichiro Nomura

Hideki Madokoro

Mayumi Ochi

A water jet peening device includes a sealed vessel provided to cover a surface of a welded portion, and adapted to be in a sealed state where an internal pressure is higher than an outside, a jet nozzle adapted to jet high-pressure water to create a cavitation bubble toward the surface of the welded portion, inside the sealed vessel, and a pressure control hole adapted to be able to adjust the internal pressure of the sealed vessel. The water jet peening device can efficiently reform a tensile residual stress on the surface of the welded portion to a compressive residual stress.

Water jet peening device

A plastically deformable almen strip is held under a predetermined underwater environment in which water jet peening is carried out, and a result of providing compressive residual stress in the water jet peening is confirmed by jetting water jet to the almen strip.

Water jet peening compressive residual stress test method, test device, and test facility

A condition setting process of determining peening conditions for water jet peening on a peening target object, an analysis process of analyzing a jet when a liquid is jetted from a nozzle model to a peening target object model and obtaining a void rate that is a volume rate of air bubbles contained in a unit volume of the liquid and a collapse rate that is a volume of the air bubbles collapsing in a unit time in the unit volume of the liquid in each position on a surface of the peening target object model, a shock pressure correlation value calculation process of obtaining a shock pressure correlation value that is a product of the void rate and the collapse rate in each position, and a range calculation process of obtaining an effective processing range in which the shock pressure correlation value on the surface of the peening target object model is greater than a predetermined value, based on the shock pressure correlation value in each position.

Method of pre-evaluating water jet peening, recording medium having program recorded thereon to execute the method, device for executing the method, and water jet peening method

A radiation shielding method and a device, and a method of processing a structure, in which a first radiation-shielded region (A) is provided by disposing a first radiation-shielding device () outside a nuclear reactor vessel (), a neutron flux detector () is moved into the radiation-shielded region (A) through a conduit tube () by moving a thimble tube () from the nuclear reactor vessel (), and an inspection/repair work of the nuclear reactor vessel () is then performed, so that an amount of radiation delivered to a worker can be easily and sufficiently reduced.

Radiation shielding method and device, and method of processing structure

It is possible to improve the workability and the stress corrosion resistance by easily performing a repairing operation in a nozzle repairing method and a nuclear reactor vessel. The repairing method includes: removing a first connection portion ((trepanned portion)) with respect to an in-core instrument tube () in a groove-welding portion (); removing the in-core instrument tube () from a lower mirror (); leaving and grooving a second connection portion ((existing welding portion)) with respect to the lower mirror () in the groove-welding portion (); inserting a new in-core instrument tube (A) into an attachment hole (); and groove-welding (so as to form a new groove-welding portion ()) the inner side of the lower mirror () so as to fix the new in-core instrument tube (A).

Nozzle repairing method and nuclear reactor vessel

[Problem] To facilitate mounting of a nozzle. [Solving Means] In a nozzle mounting structure for mounting a nozzlepenetrating through a reactor vesselhaving a hemispherical concave inner surface, the nozzle mounting structure includes a removed concave portionin which a base materialon an inner surface side of the reactor vesselis removed in a symmetrical shape around a normal line N on the hemispherical concave inner surface of the reactor vessel, a flangeprovided on the nozzle, formed in a same symmetrical shape as that of the removed concave portionaround the normal line N, and inserted into the removed concave portion, and a weld partprovided around the normal line N for welding the flangeto the reactor vessel

Nozzle mounting structure

A multi-beam scanning device is provided with a plurality of light sources that emit a plurality of light beams, respectively, a scanning system that deflects each of the plurality of light beams to scan within a predetermined scanning range, a modulating system that modulates the plurality of light beams at a plurality of frequencies, respectively, and a beam detector positioned with in the scanning range to receive the plurality of light beams respectively modulated at different frequencies. The beam detector outputs a signal representing intensity of received light beams. A separating system is provided to separate the output signal of the beam detector, on a basis of the plurality of frequencies, into a plurality of component signals, and a synchronizing signal generating circuit that generates a plurality of synchronizing signals respectively corresponding to the plurality of light beams based on the plurality of component signals.

Synchronizing signal detecting method and device for multi-beam scanning device

The optical intensity of laser light from a laser diode of a laser scanning apparatus having a polygonal mirror is detected with a monitoring photodiode. The detected output is delivered to a first switching end of a selector. The optical intensity of laser light reflected from the polygonal mirror is detected with a photosensor and the detection output is delivered to a second switching end of the selector. The selector selects either one of the switching ends in accordance with the timing of a laser scan. The associated detection signal is fed to a comparator, where it is compared with a reference voltage to produce a comparison voltage, which in turn is fed to a laser drive circuit to control the emission output of the laser diode. Despite variation in the reflectance of laser light from each reflecting surface of the polygonal mirror, a constant optical intensity is obtained on the basis of the reference voltage. In addition, even if the photosensor fails to detect the laser light, laser power control is ensured by the monitoring of the photodiode to prevent the laser diode from being overdriven.

Laser scan based recording apparatus

A scanning apparatus. The scanning apparatus has a cascade scanning optical system in which a scanning line, made by a scanning laser beam emitted by a first laser scanning optical system of a plurality of laser scanning optical systems, and a second scanning line emitted by a second laser scanning optical system of the plurality of laser scanning optical systems, are prevented from deviating from each other in either a main scanning direction or a sub-scanning direction.

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Tokyo, Japan

Nobuyuki Hori