A water jet peening apparatus includes: a nozzle, which is arranged in water and has a mouth from which water is jetted out; a detecting device, which is arranged in the water and detects sound in at least a part of a period during which the water is being jetted out from the mouth; and a processing device, which determines, based on a result of the detection by the detecting device, presence or absence of abnormality in the nozzle.

A water jet peening apparatus includes: a nozzle, which is arranged in water and has a mouth from which water is jetted out; a detecting device, which is arranged in the water and detects sound in at least a part of a period during which the water is being jetted out from the mouth; and a processing device, which determines, based on a result of the detection by the detecting device, presence or absence of abnormality in the nozzle.

A system and method for drying cavities containing spent nuclear fuel is devised. The invention utilizes a non-intrusive procedure that is based on monitoring the dew point temperature of a non-reactive gas that is circulated through the cavity. In one aspect, the invention is a system for drying a cavity loaded with spent nuclear fuel comprising: a canister forming the cavity, the cavity having an inlet and an outlet; a source of non-reactive gas; means for flowing the non-reactive gas from the source of non-reactive gas through the cavity; and means for repetitively measuring the dew point temperature of the non-reactive gas exiting the cavity.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

A system and method for performing active scanning on a nuclear fuel rod are provided. The system includes an electrically-driven neutron generator including an ion source, an accelerator, and a target; a moderator surrounding the neutron generator and configured to moderate neutrons generated by the neutron generator; a fuel rod channel disposed within the moderator, the fuel rod channel configured to receive a nuclear fuel rod and subject the nuclear fuel rod to a predetermined neutron flux; and a plurality of radiation detectors. When the nuclear fuel rod is subjected to the predetermined neutron flux, neutrons induce a secondary radiation of prompt and delayed gamma emissions, neutron emission, or a combination thereof that are detected by the plurality of radiation detectors to determine an amount of fissile material in the nuclear fuel rod and a spatial distribution of the fissile material along a length of the nuclear fuel rod.

A system and method for performing active scanning on a nuclear fuel rod are provided. The system includes an electrically-driven neutron generator including an ion source, an accelerator, and a target; a moderator surrounding the neutron generator and configured to moderate neutrons generated by the neutron generator; a fuel rod channel disposed within the moderator, the fuel rod channel configured to receive a nuclear fuel rod and subject the nuclear fuel rod to a predetermined neutron flux; and a plurality of radiation detectors. When the nuclear fuel rod is subjected to the predetermined neutron flux, neutrons induce a secondary radiation of prompt and delayed gamma emissions, neutron emission, or a combination thereof that are detected by the plurality of radiation detectors to determine an amount of fissile material in the nuclear fuel rod and a spatial distribution of the fissile material along a length of the nuclear fuel rod.

An underwater decommissioning method of a nuclear facility is disclosed. An underwater decommissioning method of a nuclear facility that includes a nuclear reactor pressure vessel and bio-protective concrete including a cavity in which the nuclear reactor pressure vessel is positioned, includes: (a) floating the nuclear reactor pressure vessel above the cavity; (b) forming an insertion part filled with water in a side spaced apart from the cavity, and installing a support part on a bottom surface of the insertion part; (c) mounting a lower portion of the nuclear reactor pressure vessel on the support part; and (d) repeatedly cutting and decommissioning the nuclear reactor pressure vessel mounted on the support part by using a cutting device in an underwater position.

A method of replacing a damaged thermal sleeve in a reactor vessel head adapter that connects a control rod drive mechanism to a reactor vessel head includes the steps of accessing the damaged thermal sleeve, removing the damaged thermal sleeve, and obtaining a replacement thermal sleeve having an elongated tubular body, a flanged region, and a plurality of slots defined in the elongated tubular body, each slot having a width which is sufficient to narrow a maximum outside diameter of the flanged region from a first diameter to a second diameter. The method further includes altering the maximum outside diameter of the flanged region on the replacement thermal sleeve, inserting the replacement thermal sleeve into an opening of a tubular member from an underside of the reactor vessel head, and expanding the maximum outside diameter of the flanged region into a recess of the reactor vessel head adapter.

A method of replacing a damaged thermal sleeve in a reactor vessel head adapter that connects a control rod drive mechanism to a reactor vessel head includes the steps of accessing the damaged thermal sleeve, removing the damaged thermal sleeve, and obtaining a replacement thermal sleeve having an elongated tubular body, a flanged region, and a plurality of slots defined in the elongated tubular body, each slot having a width which is sufficient to narrow a maximum outside diameter of the flanged region from a first diameter to a second diameter. The method further includes altering the maximum outside diameter of the flanged region on the replacement thermal sleeve, inserting the replacement thermal sleeve into an opening of a tubular member from an underside of the reactor vessel head, and expanding the maximum outside diameter of the flanged region into a recess of the reactor vessel head adapter.