Techniques, systems, and devices are disclosed for non-invasive monitoring and imaging of nuclear fuel inside a nuclear reactor using muon detector arrays. In one aspect, these detector arrays are placed outside the reactor vessel or building for investigating the reactors without access to the cores, therefore the imaging process is non-invasive. In some implementation, these detector arrays measure both muon scattering and absorption to enable imaging and characterizing not only the very high-Z fuel materials, but also other materials in the reactor, thereby obtaining a more complete picture of reactor status. When applied to damaged reactors, the disclosed proposed techniques, systems, and devices, through the process of providing an image, can reveal the presence (or absence) of damage to fuel rod assemblies or puddles of molten fuel at the bottom of the containment vessel, thus providing crucial information to guide decisions about remedial actions.

Techniques, systems, and devices are disclosed for non-invasive monitoring and imaging of nuclear fuel inside a nuclear reactor using muon detector arrays. In one aspect, these detector arrays are placed outside the reactor vessel or building for investigating the reactors without access to the cores, therefore the imaging process is non-invasive. In some implementation, these detector arrays measure both muon scattering and absorption to enable imaging and characterizing not only the very high-Z fuel materials, but also other materials in the reactor, thereby obtaining a more complete picture of reactor status. When applied to damaged reactors, the disclosed proposed techniques, systems, and devices, through the process of providing an image, can reveal the presence (or absence) of damage to fuel rod assemblies or puddles of molten fuel at the bottom of the containment vessel, thus providing crucial information to guide decisions about remedial actions.

The present invention relates to an underwater drone which is an unmanned mobile which can move in the water, and more particularly to a communication system for the underwater drone which performs communication between the underwater drone and a land-based controller (or maneuvering device). The present invention also relates to an airlock apparatus for the drone which transfers the drone into or from facilities or containers, or equipment sealed (or closed) against surrounding environment.

The communication system for an underwater drone includes an underwater drone (1) configured to move in the water, at least one transmitting and receiving antenna (2) provided in an area where the transmitting and receiving antenna (2) can communicate with the underwater drone (1) by wireless communication, and a controller or a maneuvering device (5) connected to the at least one transmitting and receiving antenna (2) by a wired cable (4) and configured to control the underwater drone (1).

Aspects of monitoring using harsh environment sensing devices and systems are described. Multiple parameters are detected using the sensing devices immersed in a harsh environment such as a caustic solution. The parameters detected using the harsh environment sensing devices and systems include pressure, depth, density, temperature, or any combination thereof.

Aspects of monitoring using harsh environment sensing devices and systems are described. Multiple parameters are detected using the sensing devices immersed in a harsh environment such as a caustic solution. The parameters detected using the harsh environment sensing devices and systems include pressure, depth, density, temperature, or any combination thereof.

A system for monitoring a reactor module housed in a reactor bay may include a mounting structure and one or more extendable attachment mechanisms connected to the mounting structure. Additionally, one or more monitoring devices may be operably coupled to the one or more extendable attachment mechanism, and the one or more extendable attachment mechanisms may be configured to selectively position the one or more monitoring devices at varying distances from a wall of the reactor bay to place the one or monitoring devices in proximity to the reactor module.

A system for monitoring a reactor module housed in a reactor bay may include a mounting structure and one or more extendable attachment mechanisms connected to the mounting structure. Additionally, one or more monitoring devices may be operably coupled to the one or more extendable attachment mechanism, and the one or more extendable attachment mechanisms may be configured to selectively position the one or more monitoring devices at varying distances from a wall of the reactor bay to place the one or monitoring devices in proximity to the reactor module.

A water jet peening device includes a sealed vessel provided to cover a surface of a welded portion, and adapted to be in a sealed state where an internal pressure is higher than an outside, a jet nozzle adapted to jet high-pressure water to create a cavitation bubble toward the surface of the welded portion, inside the sealed vessel, and a pressure control hole adapted to be able to adjust the internal pressure of the sealed vessel. The water jet peening device can efficiently reform a tensile residual stress on the surface of the welded portion to a compressive residual stress.

A water jet peening device includes a sealed vessel provided to cover a surface of a welded portion, and adapted to be in a sealed state where an internal pressure is higher than an outside, a jet nozzle adapted to jet high-pressure water to create a cavitation bubble toward the surface of the welded portion, inside the sealed vessel, and a pressure control hole adapted to be able to adjust the internal pressure of the sealed vessel. The water jet peening device can efficiently reform a tensile residual stress on the surface of the welded portion to a compressive residual stress.

A method for inspecting a nuclear reactor part includes placing an optical sensor (38) in front of the part to be inspected using a carrier (40); acquiring at least a first image of at least a reference portion of the part using the optical sensor (38), the or each first image being taken with a first magnification; reconstituting a three-dimensional model of said reference portion of the part using the or each first acquired image; calculating the position of an area to be inspected relative to the optical sensor (38) using the three-dimensional model; acquiring at least a second image of the area to be inspected using the optical sensor (38), the or each second image of the area to be inspected being taken with a second magnification higher than the first magnification.