Abstract: A method for manufacturing a microparticulate anatase or rutile titanium oxide dispersion from a peroxotitanic acid solution optionally containing tin, wherein the method for manufacturing an anatase or rutile titanium oxide dispersion is characterized in that the peroxotitanic acid solution is fed continuously to a flow reactor and subjected to hydrothermal treatment at 150 to 250° C. and 0.5 to 10 MPa. The invention makes it possible to provide a method for manufacturing a microparticulate anatase or rutile titanium oxide dispersion having excellent stability in regard to the titanium oxide microparticles and enabling a high-transparency photocatalytic thin film to be produced, and to provide a member having a photocatalytic thin film formed on the surface using this dispersion.

Abstract: A plant with piping mounted on branch pipe, wherein said piping which introduces gas has a nozzle portion as a joint portion to a vessel and a branch portion connected with a branch pipe; and wherein an enlarged passage portion is formed at least at one of said branch portion and said nozzle portion, and a passage sectional area of said enlarged passage portion is larger than that of said piping other than said enlarged passage portion. Since the flow velocity of the gas flowing inside slows down at the enlarged passage portion, the occurrence of acoustic resonance at the branch portion or the nozzle portion can be suppressed. Accordingly, the fluctuation pressure of the gas flowing in the piping can be reduced even more.

Abstract: A method for manufacturing a microparticulate anatase or rutile titanium oxide dispersion from a peroxotitanic acid solution optionally containing tin, wherein the method for manufacturing an anatase or rutile titanium oxide dispersion is characterized in that the peroxotitanic acid solution is fed continuously to a flow reactor and subjected to hydrothermal treatment at 150 to 250° C. and 0.5 to 10 MPa. The invention makes it possible to provide a method for manufacturing a microparticulate anatase or rutile titanium oxide dispersion having excellent stability in regard to the titanium oxide microparticles and enabling a high-transparency photocatalytic thin film to be produced, and to provide a member having a photocatalytic thin film formed on the surface using this dispersion.

Abstract: In implementing an induction heating stress improvement (IHSI) method in a nuclear plant, cooling characteristic with respect to the inner surface of piping is improved by appropriate structure/layout of nozzles, and further, the cooling effect when applying IHSI to a real machine is verified by installing a thermometer, as well as air in the portion subjected to IHSI is removed by heating the piping prior to the execution of IHSI.

Abstract: A natural circulation boiling water reactor provides to a chimney with a plurality of tubes. That is to say, each of the plurality of tubes partitions the coolant flow path above a core. Thus, unlike the conventional natural circulation boiling water reactor providing the flow path partition wall grid in which the plate members are made integral by welding and coolant flow paths are partitioned, the chimney of the natural circulation boiling water reactor can reduce the number of welded portions because the edges of the four corners of each flow path do not need to be welded. The natural circulation boiling water reactor can avoid removal as a single unit, as in the case of the flow path partition wall grid in the conventional natural circulation boiling water reactor, by detaching each tube. The chimney can be easily detached from the reactor pressure vessel.

Abstract: The object of the invention is to accurately evaluate integrity of vibration of a dryer of an actual system. The evaluating method for integrity of vibration of a steam dryer using a reduced model in a nuclear plant including the steam dryer for reducing moisture of steam generated inside a steam dome of a nuclear reactor pressure vessel, and a plurality of main steam pipes for transporting the steam to outside includes the steps of performing a steam test with the reduced model, calculating fluctuating stress applied to the steam dryer, and confirming integrity of vibration. According to the invention, it is possible to evaluate the pressure fluctuation of a dryer of an actual system more accurately.

Abstract: A natural circulation boiling water reactor includes a reactor pressure vessel, a chimney including a lattice member and arranged above a core in said reactor pressure vessel, and a plurality of thermocouple extension wire pulling conduits into which at least one temperature detection thermocouple and at least one cable connected to the temperature detection thermocouple are inserted. At least one of thermocouple extension wire pulling conduits is disposed on an upper end surface of the lattice member and is directly mounted to the upper end surface of the lattice member.

Abstract: A handling method for a natural circulation boiling water reactor having a chimney having cylindrical chimney shell disposed above a core in a reactor pressure vessel, a plurality of square tubes disposed in the chimney shell, and a grid support plate with grid holes supporting and in communication with a lower end portion of the square tubes so that adjacent square tubes are disposed at an interval which exceeds the width of one square tube between them. The method includes steps shifting predetermined ones of the square tubes to the interval between the square tubes, and performing maintenance and inspection of members around a core via the grid holes which appear at positions from which the predetermined square tubes are taken out due to the shift of the predetermined square tubes.

Abstract: A plant with piping mounted on branch pipe, wherein said piping which introduces gas has a nozzle portion as a joint portion to a vessel and a branch portion connected with a branch pipe; and wherein an enlarged passage portion is formed at least at one of said branch portion and said nozzle portion, and a passage sectional area of said enlarged passage portion is larger than that of said piping other than said enlarged passage portion. Since the flow velocity of the gas flowing inside slows down at the enlarged passage portion, the occurrence of acoustic resonance at the branch portion or the nozzle portion can be suppressed. Accordingly, the fluctuation pressure of the gas flowing in the piping can be reduced even more.

Abstract: A WDM based sensor system, a method of interrogating a plurality of sensor elements, and a WDM based sensor interrogation system. The WDM based sensor system comprises a WDM MUX/DEMUX element for demultiplexing an optical input signal into a plurality of substantially non-overlapping signals in respective sensing channels; one or more sensor elements disposed in each sensing channel; wherein the MUX/DEMUX element multiplexes sensing signals from the respective sensing channels into an optical return signal; and a detector element for detecting the sensing signals in the multiplexed optical return signal.

Abstract: A natural circulation boiling water reactor includes a reactor pressure vessel, a chimney including a lattice member and arranged above a core in the reactor pressure vessel, and at least one thermocouple extension wire pulling conduit into which a temperature detection thermocouple and a cable connected to said temperature detection thermocouple are inserted. The thermocouple extension wire pulling conduit is disposed on an upper end surface of the lattice member and mounted to the upper end surface of the lattice member.

Abstract: A handling method for a natural circulation boiling water reactor having a chimney having cylindrical chimney shell disposed above a core in a reactor pressure vessel, a plurality of square tubes disposed in the chimney shell, and a grid support plate with grid holes supporting and in communication with a lower end portion of the square tubes so that adjacent square tubes are disposed at an interval which exceeds the width of one square tube between them. The method includes steps shifting predetermined ones of the square tubes to the interval between the square tubes, and performing maintenance and inspection of members around a core via the grid holes which appear at positions from which the predetermined square tubes are taken out due to the shift of the predetermined square tubes.

Abstract: A chimney lattice is arranged in a reactor pressure vessel. Thermocouple extension wire pulling conduits inserting a temperature detection thermocouple and a cable connected to the thermocouple are mounted to the upper end of the chimney lattice. By mounting the thermocouple extension wire pulling conduit on the upper end of the chimney lattice, the thermocouple extension wire pulling conduit does not become an obstacle when the fuel assembly is taken out from the chimney. Because the thermocouple extension wire pulling conduit is installed at the upper end of the chimney, the replacement of the thermocouple damaged is easy.

Abstract: A natural circulation boiling water reactor provides to a chimney with a plurality of tubes. That is to say, each of the plurality of tubes partitions the coolant flow path above a core. Thus, unlike the conventional natural circulation boiling water reactor providing the flow path partition wall grid in which the plate members are made integral by welding and coolant flow paths are partitioned, the chimney of the natural circulation boiling water reactor can reduce the number of welded portions because the edges of the four corners of each flow path do not need to be welded. The natural circulation boiling water reactor can avoid removal as a single unit, as in the case of the flow path partition wall grid in the conventional natural circulation boiling water reactor, by detaching each tube. The chimney can be easily detached from the reactor pressure vessel.

Abstract: A functional optical device has cores which are trenches, different portions of the cores being formed from different core materials. The optical device can be formed by forming trenches 5, 7, 9 within a substrate (normally a substrate 1 covered by a cladding layer 3), covering at least part of at least one trench 7 with a cover 11, depositing a first cladding layer 13 of a first cladding material to fill the trenches 5, 9 which are not covered, removing the cover 11, depositing a second cladding layer 15 of a second cladding material to fill the trenches 7 which were previously covered, removing core material outside the trenches 5, 7, 9, and applying a cladding layer to cover the trenches.

Abstract: A functional optical device has cores which are trenches, different portions of the cores being formed from different core materials. The optical device can be formed by forming trenches 5,7,9 within a substrate (normally a substrate 1 covered by a cladding layer 3), covering at least part of at least one trench 7 with a cover 11, depositing a first cladding material to fill the trenches 5,9 which are not covered, removing the cover 11, depositing a second cladding layer 15 of a second cladding material to fill the trenches 7 which were previously covered, removing core material outside the trenches 5,7,9 and applying a cladding layer to cover the trenches.

Abstract: In implementing an induction heating stress improvement (IHSI) method in a nuclear plant, cooling characteristic with respect to the inner surface of piping is improved by appropriate structure/layout of nozzles, and further, the cooling effect when applying IHSI to a real machine is verified by installing a thermometer, as well as air in the portion subjected to IHSI is removed by heating the piping prior to the execution of IHSI.

Abstract: A functional optical device has cores which are trenches, different portions of the cores being formed from different core materials. The optical device can be formed by forming trenches 5,7,9 within a substrate (normally a substrate 1 covered by a cladding layer 3), covering at least part of at least one trench 7 with a cover 11, depositing a first cladding material to fill the trenches 5,9 which are not covered, removing the cover 11, depositing a second cladding layer 15 of a second cladding material to fill the trenches 7 which were previously covered, removing core material outside the trenches 5,7,9 and applying a cladding layer to cover the trenches.

Abstract: An optical waveguide apparatus comprises a substrate (1), a patterned waveguide as a core (4), and an upper cladding layer (10) formed on the substrate. The core is surrounded by a cladding comprising the substrate as a lower cladding layer and the upper cladding layer and smaller in refractive index than the core. The core and the cladding are integrally coupled to each other in a manner such that temperature-dependent expansion or contraction is performed substantially in accordance the characteristic of the cladding. The core and the cladding are made of materials selected so that the variation in optical path length according to the temperature-dependent expansion or contraction of the cladding is canceled by the variation in optical path length according to temperature-dependent variation in refractive index of the core.

Abstract: An optical waveguide apparatus comprises a substrate (1), a patterned waveguide as a core (4), and an upper cladding layer (10) formed on the substrate. The core is surrounded by a cladding comprising the substrate as a lower cladding layer and the upper cladding layer and smaller in refractive index than the core. The core and the cladding are integrally coupled to each other in a manner such that temperature-dependent expansion or contraction is performed substantially in accordance the characteristic of the cladding. The core and the cladding are made of materials selected so that the variation in optical path length according to the temperature-dependent expansion or contraction of the cladding is canceled by the variation in optical path length according to temperature-dependent variation in refractive index of the core.