Abstract: Provided is a sensor system which can detect a thickness reduction, a crack, or the like of a pipe or a container covered with a thick coating member through ultrasonic inspection without attachment and detachment of the coating member. A sensor system used for nondestructive inspection includes a sensor attached to a surface of an inspection target, a sensor coil that is electrically connected to the sensor via a first cable, a first electromagnetic wave blocking member that is disposed between the surface of the inspection target and the sensor coil, a sensor side coil that is disposed to face the sensor coil with a gap and is coupled to the sensor coil through electromagnetic induction, and a probe side coil that is disposed to be separated from the sensor side coil and is electrically connected to the sensor side coil via a second cable.

Abstract: A control rod operation generates a rod insertion block signal during operation of a reactor. Four neutron detector assemblies including a plurality of LPRMs arranged in an axial direction of a core are arranged adjacent to a plurality of insertion selection control rods, respectively, which are simultaneously inserted into the core. Neutron flux ratio calculation units are arranged in each of the neutron detector assemblies, and ratios (neutron flux ratios BA/AA, CA/AA, and DA/AA) of an average LPRM signal of the respective LPRMs at positions B, C, and D to an average LPRM signal of the respective LPRMs at a position A which is closest to the control rod insertion end of the core are calculated. When the largest neutron flux ratio out of the neutron flux ratios exceeds a set neutron flux ratio, a rod insertion block signal which is generated by a local range rod insertion monitor is output.

Abstract: There is provided, for example, an ultrasonic probe capable of improving the accuracy of testing of a curved-surface structure. An array sensor (ultrasonic array sensor) includes multiple elements (oscillators) to generate an ultrasonic wave. Water (propagation member) is disposed between the array sensor and steel (test target) to propagate the ultrasonic wave. At least one reflection section reflects the ultrasonic wave reflected and returned from the surface of or the inside of the steel, and causes the ultrasonic wave to fall on any of the elements.

Abstract: An ultrasonic inspection system includes an ultrasonic sensor and a control device. The ultrasonic sensor has a piezoelectric element that transmits and receives ultrasonic waves and plate portions and that are arranged so as to contact an upper surface of the piezoelectric element and have different thicknesses. The control device acquires a propagation time of a reflected wave reflected on an upper surface of the plate portion, calculates a sound velocity of the plate portion using the propagation time of the reflected wave and a thickness of the plate portion, and corrects a sound velocity of a pipe and acquires a sound velocity of the plate portion based on the calculated sound velocity. In addition, the control device acquires a propagation time of a reflected wave reflected on an upper surface of the plate portion, and calibrates a time axis based on the propagation time of the reflected wave, a thickness of the plate portion, and the sound velocity of the plate portion.

Abstract: A vibration isolation supporting structure and a vibration isolation system that can prevent a high-frequency vibration and a low-frequency vibration generated on a floor of a building. The vibration isolation supporting structure includes a plurality of supporting portions erected facing each other in a predetermined area near a wall of a floor of a building, a supporting structure supported on the floor by the supporting portions, and a fixing device configured to fix the supporting structure to the floor, and when receiving a release command, the fixing device releases fixing of the supporting structure to the floor.

Abstract: A control rod drive system and an inspection method of the control rod drive system capable of performing inspection safely and effectively. A control rod drive system controlling operation by supplying a hydraulic pressure to control rod drive mechanisms. A plurality of first hydraulic control units supply the hydraulic pressure to corresponding control rod drive mechanisms and a second hydraulic control unit supplies the hydraulic pressure to corresponding control rod drive mechanisms of the first hydraulic control unit as an inspection target instead of the first hydraulic control unit.

Abstract: A high reliable water injection device is provided that injects water into a reactor containment vessel and can reliably shut off cooling water at normal times and quickly and reliably inject water into the reactor containment vessel without the need for external power, in a case of emergency. The water injection device injects water into a reactor containment vessel includes a flow path through which cooling water is supplied; a disk that closes the flow path; a swing arm that is connected to the disk and performs closing and opening of the flow path by the disk; and a weight that is connected to the swing arm via a swing lever, in which the weight is supported by a support member made of a low melting point alloy.

Abstract: When a power source is lost after an operation stop of a nuclear power plant, a first open/close valve is opened via a first battery at an early stage and steam in a reactor pressure vessel (RPV) is condensed in a suppression pool. The heat of the water in the suppression pool is transmitted to a cooling water pool located below inner space between first and second reactor containment vessels surrounding the RPV. A second open/close valve is opened via a second battery at the early stage and cooling water in a tank is injected into the RPV. After the early stage, a third open/close valve is opened via a third battery, and a cooling medium becomes steam by an evaporator in the RPV, the steam being condensed by a condenser disposed in the inner space to become a liquid of the cooling medium and is returned to the evaporator.

Abstract: There is provided a core of a boiling water reactor that can be operated without loading a new fuel assembly at an operation cycle before decommissioning. The core of the boiling water reactor includes multiple fuel assemblies loaded in a square lattice shape. The multiple fuel assemblies are arranged in the core based on the number of residence cycles of fuel assemblies laterally adjacent and longitudinally adjacent to a fuel assembly having the shortest loading period in core cross section. The arrangement of fuel assemblies is also based on the number of residence cycles of fuel assemblies diagonally adjacent to the fuel assembly having the shortest loading period.

Abstract: An aqueous solution of alkali hexahydroxo platinate is produced. As a alkali hexahydroxo platinate, sodium hexahydroxoplatinate or potassium hexahydroxoplatinate is used. The aqueous solution of alkali hexahydroxo platinate is passed through a hydrogen form cation exchange resin layer in a cation exchange resin tower. The aqueous solution of alkali hexahydroxo platinate makes contact with the hydrogen form cation exchange resin of the hydrogen form cation exchange resin layer, thus a suspension of hexahydroxo platinic is generated. If gamma rays are irradiated to the suspension, a platinum oxide colloidal solution in which colloidal particles including a platinum dioxide, a platinum monoxide, and a platinum hydroxide exist is generated. In a platinum oxide colloidal solution, the content of impurities is little and a noble metal compound is dispersed stably in water.

Abstract: The present disclosure provides a method for relieving a corrosive environment of a boiling water reactor, the method including a step of injecting hydrogen and a noble metal compound into water to be replenished into the reactor pressure vessel during a period of a generating operation of a boiling water nuclear power plant including the reactor pressure vessel. In the method, the hydrogen is injected into water to be supplied into the reactor pressure vessel, and the noble metal compound is injected into water in a line of the boiling water nuclear power plant in which a concentration of oxygen or hydrogen peroxide is stoichiometrically higher than the concentration of hydrogen at which hydrogen undergoes a chemical reaction to turn to water.

Abstract: To more reliably supply cooling water to a reactor pressure vessel and a reactor containment vessel using a back-up building if a severe accident should occur, a boiling water type nuclear power plant includes a nuclear reactor building including a reactor containment vessel, and an external building, which is installed independently outside the nuclear reactor building and which has an anti-hazard property. The external building has a power source and an operating panel independent of the nuclear reactor building. The boiling water type nuclear power plant includes a water injection pump installed inside the external building, an alternative water injection pipe performing water injection at least on a reactor pressure vessel or the reactor containment vessel in the nuclear reactor building from the water injection pump, and a valve connected to the alternative water injection pipe, making it possible to perform alternative water injection if a severe accident occurs.

Abstract: An atomic power plant is provided including a primary containment vessel (PCV) 1, a reactor pressure vessel (RPV) 3, a main steam line 4, two steam safety relief valves (SRVs) 6, a pressure suppression pool (S/P) 8, an SRV exhaust pipe 9 which is connected to a quencher 10, a temperature measuring instrument 12 which measures a temperature inside the quencher 10, an SRV controller 13 which controls opening and closing of the SRVs 6. After a lapse of predetermined time from when the SRV 6 is opened, in a case where it is determined that a temperature detected by the temperature measuring instrument 12 is equal to or smaller than a predetermined threshold value, the SRV controller 13 causes the SRV 6 to which the temperature measuring instrument 12 detecting the temperature leads, to be closed and to be prohibited from being opened.

Abstract: Chirp waves generated in a transmitting/receiving unit is supplied to ultrasonic sensors. Signals output from the ultrasonic sensors are supplied to the transmitting/receiving unit and summed in a signal processing/recording unit. The signal processing/recording unit performs mutual correlation processing between the summed signals and the chirp waves and calculates a peak generation time difference. Necessity of exchanging a pipe is determined by calculating and recording the thickness of a pipe from the calculated time difference and calculating a difference between thicknesses measured in the past and the present.

Abstract: The laser welding apparatus includes a welding head and a welding head scanning apparatus. A collimate lens installed on a head body of the welding head is arranged opposite to an end face of optical fibers. The welding head includes only the collimate lens as a lens and the length is shortened. A laser generated by a laser oscillator is introduced into the optical fiber, enters the collimate lens, and then is converted to a parallel beam by the collimate lens. The laser of a parallel beam is irradiated on a surface a welding portion of the welding object through a laser path and the surface of the welding portion is melted. Metallic powder is jetted from powder feed paths formed in a head body to the melted portion and build-up welding is performed on the surface of the welding portion.

Abstract: A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.

Abstract: A control rod drive mechanism includes an outer tube and a guide tube which is arranged in the outer tube and is held by the outer tube. Furthermore, the control rod drive mechanism includes a spool piece with an inner magnet coupling and a rotary shaft connected to the inner magnet coupling arranged internally. The lower end portion of the outer tube is supported by the spool piece in the spool piece. The outside diameter of the outer tube, through the length of the outer tube, is smaller than the inside diameter of the spool piece and the outer tube, in the radial direction of the outer tube, is not projected outside the inner surface of the spool piece. Therefore, the installation places of the O-rings which are a seal member are reduced and the time required for maintenance of the control rod drive mechanism can be shortened.

Abstract: Since an investigation apparatus is connected through a cable and is remotely operated, the cable may be caught by an obstacle, thereby limiting a movement range of the investigation apparatus. An investigation system 15 includes an investigation apparatus 50 which moves to a position where an investigation target is investigated, by using a traveling section 51 and a support apparatus 30 which moves to a position where letting-off and winding of a cable 14 for an investigation apparatus which is connected to the investigation apparatus 50 are performed, by using a traveling section 31. The investigation apparatus 50 outputs an image of the investigation target which is captured by a camera section 53, to an investigation apparatus controller 40 via the cable 14 for an investigation apparatus.

Abstract: To realize an object of providing an eddy current inspection device which is able to control a sensitivity decrease, and is able to reliably detect a defect.

Abstract: In an electrodeposition treatment of an iron-group metal ion-containing liquid, without being influenced by the properties of the iron-group metal ion-containing liquid, iron-group metal ions are efficiently removed from the liquid by precipitation. An anode chamber 2A provided with an anode 2 and a cathode chamber 3A provided with a cathode 3 are separated from each other by a cation exchange membrane 5, an iron-group metal ion-containing liquid is charged into the anode chamber 2A, a cathode liquid is charged into the cathode chamber 3A, and by applying the voltage between the anode 2 and the cathode 3, iron-group metal ions in the liquid in the anode chamber 2A are moved into the liquid in the cathode chamber 3A through the cation exchange membrane 5, so that an iron-group metal is precipitated on the cathode 3.