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.

Abstract: A control rod for nuclear reactors includes four wings including neutron absorbers containing hafnium, a front end structural member which has a cross shape in cross section and includes brackets bonded to the leading ends of the wings, and a terminal end structural member which has a cross shape in cross section and includes brackets bonded to the tailing ends of the wings. The four wings are bonded to a wing-bonding member including a cross-shaped center shaft so as to form a cross shape. The front end structural member and the wing-bonding member are made of a zirconium alloy. The wings include neutron-absorbing plates having neutron-absorbing portions and each have an outer surface which is opposed to a fuel assembly and at which a hafnium-zircaloy composite member covered with zircaloy is disposed. The neutron-absorbing plates are opposed to each other with trap spaces disposed therebetween.

Abstract: A control rod for nuclear reactors includes four wings including neutron absorbers containing hafnium, a front end structural member which has a cross shape in cross section and includes brackets bonded to the leading ends of the wings, and a terminal end structural member which has a cross shape in cross section and includes brackets bonded to the tailing ends of the wings. The four wings are bonded to a wing-bonding member including a cross-shaped center shaft so as to form a cross shape. The front end structural member and the wing-bonding member are made of a zirconium alloy. The wings include neutron-absorbing plates having neutron-absorbing portions and each have an outer surface which is opposed to a fuel assembly and at which a hafnium-zircaloy composite member covered with zircaloy is disposed. The neutron-absorbing plates are opposed to each other with trap spaces disposed therebetween.

Abstract: A control rod for nuclear reactors includes four wings including neutron absorbers containing hafnium, a front end structural member which has a cross shape in cross section and includes brackets bonded to the leading ends of the wings, and a terminal end structural member which has a cross shape in cross section and includes brackets bonded to the tailing ends of the wings. The four wings are bonded to a wing-bonding member including a cross-shaped center shaft so as to form a cross shape. The front end structural member and the wing-bonding member are made of a zirconium alloy. The wings include neutron-absorbing plates having neutron-absorbing portions and each have an outer surface which is opposed to a fuel assembly and at which a hafnium-zircaloy composite member covered with zircaloy is disposed. The neutron-absorbing plates are opposed to each other with trap spaces disposed therebetween.

Abstract: An incore monitoring method of a nuclear reactor, includes, measuring neutron flux levels at pitch levels corresponding to local power range monitor sensors arranged along an axial direction inside a detector assembly installed in a nuclear reactor; performing power calculation, including calculation of thermal characteristics, of fuel assembly group consisting of fuel assemblies adjacent to the corresponding detector assembly, based on indicated values of the local power range monitor sensors of the corresponding detector assembly at a first time, calculating thermal characteristics at a second, subsequent time in which the power calculation is not calculated, based on values indicated by the local power range monitor sensors and calculated thermal characteristics at the first time and values indicated by the corresponding local power range monitor sensors at the second time, and monitoring the calculated thermal characteristics.

Abstract: An incore monitoring method of a nuclear reactor, includes, measuring neutron flux levels at pitch levels corresponding to local power range monitor sensors arranged along an axial direction inside a detector assembly installed in a nuclear reactor; performing power calculation, including calculation of thermal characteristics, of fuel assembly group consisting of fuel assemblies adjacent to the corresponding detector assembly, based on indicated values of the local power range monitor sensors of the corresponding detector assembly at a first time, calculating thermal characteristics at a second, subsequent time in which the power calculation is not calculated, based on values indicated by the local power range monitor sensors and calculated thermal characteristics at the first time and values indicated by the corresponding local power range monitor sensors at the second time, and monitoring the calculated thermal characteristics.