Abstract: According to embodiments, a light water reactor uranium fuel assembly is capable of reducing heating values of both Am-241 and Cm-244, to reduce the amount of generated vitrified waste without using fast reactors. The light water reactor uranium fuel assembly is a light water reactor uranium fuel assembly to be used in a nuclear fuel cycle that extracts. An americium isotope is extracted at the time of reprocessing of spent fuel to be added to a fuel, in which a weight fraction W (unit: wt %) of americium 241 to be added to a fuel heavy metal is in ranges of W<?0.006e2+0.12e?0.43 (enrichment: 5 wt % or more), W<?0.000356e+0.00357 (enrichment: 4.2 wt % or more and less than 5.0 wt %) with respect to an average enrichment of uranium 235 e (unit: wt %) of the fuel assembly.

Abstract: In one embodiment, a charged-particle trajectory measurement apparatus for measuring a trajectory of a cosmic ray muon as a charged particle includes: a plurality of detectors, each of which generates a detection signal at the time of detecting a cosmic ray muon; a signal processing circuit that processes the detection signal from the detector; a time calculator that calculates the generation time point of the detection signal from the detector on the basis of the signal outputted from the signal processing circuit; a trajectory calculator that calculates the trajectory of the cosmic ray muon on the basis of the generation time point of the detection signal and the positional information of the detector having detected the cosmic ray muon, wherein the signal processing circuit and each of the detectors are integrally configured by being coupled to each other.

Abstract: In one embodiment, a charged-particle trajectory measurement apparatus for measuring a trajectory of a cosmic ray muon as a charged particle includes: a plurality of detectors, each of which generates a detection signal at the time of detecting a cosmic ray muon; a signal processing circuit that processes the detection signal from the detector; a time calculator that calculates the generation time point of the detection signal from the detector on the basis of the signal outputted from the signal processing circuit; a trajectory calculator that calculates the trajectory of the cosmic ray muon on the basis of the generation time point of the detection signal and the positional information of the detector having detected the cosmic ray muon, wherein the signal processing circuit and each of the detectors are integrally configured by being coupled to each other.

Abstract: According to one embodiment, a charged-particle measurement apparatus comprising: a plurality of gas detectors in each of which gas for detecting passage of a charged particle is enclosed; a trajectory calculator configured to calculate a trajectory of the charged particle based on detection signals outputted from the gas detectors and each of the parameters associated with the gas detectors; a measurer configured to measure an object based on the trajectory of the charged particle, the object being a measurement target; a signal intensity acquirer configured to acquire signal intensity of the detection signals; an operating state monitor configured to evaluate the operating states of the gas detectors based on the signal intensity corresponding to the gas detectors; and a parameter updating processor configured to update at least one parameter when at least one of the operating states of the gas detectors associated with this parameter changes.

Abstract: According to embodiments, a light water reactor uranium fuel assembly is capable of reducing heating values of both Am-241 and Cm-244, to reduce the amount of generated vitrified waste without using fast reactors. The light water reactor uranium fuel assembly is a light water reactor uranium fuel assembly to be used in a nuclear fuel cycle that extracts. An americium isotope is extracted at the time of reprocessing of spent fuel to be added to a fuel, in which a weight fraction W (unit: wt %) of americium 241 to be added to a fuel heavy metal is in ranges of W<?0.006e2+0.12e?0.43 (enrichment: 5 wt % or more), W<?0.000356e+0.00357 (enrichment: 4.2 wt % or more and less than 5.0 wt %) with respect to an average enrichment of uranium 235 e (unit: wt %) of the fuel assembly.

Abstract: According to an embodiment, a design method for a light-water reactor fuel assembly comprises: accumulating a determined fuel data, showing that each of a combination of p·n/N and e is feasible as the core or not, wherein N is a number of the fuel rods in the fuel assembly, n is a number of the fuel rods containing the burnable poison, p is a ratio wt % of the burnable poison in the fuel, and e is an enrichment wt % of the uranium 235 contained in the fuel assembly; formulating a criterion formula which determines whether a combination of p·n/N and e is feasible as a core or not and is formulated based on the determined fuel data; and determining whether a temporarily set composition of the fuel assembly is approved as a core or not based on the criterion formula.

Abstract: According to an embodiment, a design method for a light-water reactor fuel assembly comprises: accumulating a determined fuel data, showing that each of a combination of p·n/N and e is feasible as the core or not, wherein N is a number of the fuel rods in the fuel assembly, n is a number of the fuel rods containing the burnable poison, p is a ratio wt % of the burnable poison in the fuel, and e is an enrichment wt % of the uranium 235 contained in the fuel assembly; formulating a criterion formula which determines whether a combination of p·n/N and e is feasible as a core or not and is formulated based on the determined fuel data; and determining whether a temporarily set composition of the fuel assembly is approved as a core or not based on the criterion formula.

Abstract: A muon tracker includes a drift tube detector having a plurality of drift tube arrays, a detection time-difference calculation circuit configured to calculate a detected time-difference between a plurality of time data detected at least two of the drift tubes, a time-difference information database that stores a relationship between a plurality of predetermined tracks of the muon passing the drift tube detector and a predetermined time-difference of possible detected time data to be detected at least two of the drift tubes where each of the plurality of predetermined tracks passes, a time-difference referring circuit configured to refer the detected time-difference calculated at the detection time-difference calculation circuit with the predetermined time-difference stored in the time-difference information database, and a muon track determining circuit configured to determine a muon track as the predetermined track of the muon corresponding to the predetermined time-difference that matches the best with the

Abstract: A muon tracker includes a drift tube detector having a plurality of drift tube arrays, a detection time-difference calculation circuit configured to calculate a detected time-difference between a plurality of time data detected at least two of the drift tubes, a time-difference information database that stores a relationship between a plurality of predetermined tracks of the muon passing the drift tube detector and a predetermined time-difference of possible detected time data to be detected at least two of the drift tubes where each of the plurality of predetermined tracks passes, a time-difference referring circuit configured to refer the detected time-difference calculated at the detection time-difference calculation circuit with the predetermined time-difference stored in the time-difference information database, and a muon track determining circuit configured to determine a muon track as the predetermined track of the muon corresponding to the predetermined time-difference that matches the best with the

Abstract: An inner image generating apparatus includes a first receiver configured to receive an inlet track information and a first passage time of a muon, a second receiver configured to receive an outlet track information and a second passage time of the muon, a displacement calculator configured to calculate a track displacement of a track of the muon based on the inlet and outlet track information, a mean energy calculator configured to calculate a mean energy of the muon based on a time-difference between the first passage and the second passage time, a data integration circuit configured to integrate multiplied data multiplying the track displacement and the mean energy on a projected plane, and an image generating circuit configured to generate an inner image of the structure by identifying a position of matter at the projected plane based on an integrated multiplied data.

Abstract: An inner image generating apparatus includes a first receiver configured to receive an inlet track information and a first passage time of a muon, a second receiver configured to receive an outlet track information and a second passage time of the muon, a displacement calculator configured to calculate a track displacement of a track of the muon based on the inlet and outlet track information, a mean energy calculator configured to calculate a mean energy of the muon based on a time-difference between the first passage and the second passage time, a data integration circuit configured to integrate multiplied data multiplying the track displacement and the mean energy on a projected plane, and an image generating circuit configured to generate an inner image of the structure by identifying a position of matter at the projected plane based on an integrated multiplied data.