A nuclear reactor is designed to allow efficient packing of components within the reactor vessel, such as by offsetting the core, and/or vertically stacking components. The in-vessel storage system can be separate from the support cylinder and these components can be fabricated and shipped separately and coupled together at the construction site. Furthermore, the in-vessel storage system can be located adjacent to the core rather than being located circumferentially around it, and may also be located beneath the heat exchanger to further improve packing of components within the vessel. Through these, and other changes, the delicate components can be manufactured in a manufacturing facility, assembled, and shipped by commercial transportation options without exceeding the shipping envelope.

A nuclear fuel assembly is constructed with fuel assembly components that are wire wrapped and positioned in hexagonal rings within a fuel assembly duct. The fuel assembly components positioned in an outermost ring of the fuel assembly are wire wrapped with a pitch that is shorter than fuel assembly components positioned at an interior ring of the fuel assembly. The shorter pitch at the outer ring of the fuel assembly increases pressure drop of a coolant fluid at the edge and corner subchannels and thereby reduces the temperature gradient across the fuel assembly, which provides a higher output temperature of the nuclear reactor without substantially increasing peak temperature of the fuel cladding.

A pressure vessel comprises a pressure vessel body having a rectangular cross-sectional shape and formed to extend in the direction of flow of fluids, and the pressure vessel body includes a first flow channel which is formed in the longitudinal direction of the pressure vessel body and through which a first fluid is caused to flow, a second flow channel which is formed in the longitudinal direction of the pressure vessel body and through which a second fluid is caused to flow, a first-fluid inlet-outlet port which is provided in one longitudinal end surface of the pressure vessel body and connects with the first flow channel and through which the first fluid is caused to flow in or out, a second-fluid inlet-outlet port which is provided in the other longitudinal end surface of the pressure vessel body and connects with the second flow channel and through which the second fluid is caused to flow in or out, an opening portion which is provided in the one longitudinal end surface of the pressure vessel body and connects with the second flow channel, and a closing member which closes the opening portion in a demountable manner.

A method of using a pipe cap assembly for a normally-sealed system includes attaching the base portion of a pipe cap to a pipe of a normally sealed system. A transition cap having internal threads is releasably coupled to an externally-threaded cylindrical connector portion of the pipe cap for sealing the same during normal operation. When access to the normally sealed system is required, the transition cap is unthreaded from the pipe cap, and a transition fitting is installed instead. A drain hose, vent hose, or the like, may be coupled to an access port of the transition fitting and fastened thereto for passing fluids to or from the normally sealed system. Alternatively, a test instrument may be coupled to the access port. Thereafter, the transition fitting is removed, and the transition cap is re-installed.

A method of using a pipe cap assembly for a normally-sealed system includes attaching the base portion of a pipe cap to a pipe of a normally sealed system. A transition cap having internal threads is releasably coupled to an externally-threaded cylindrical connector portion of the pipe cap for sealing the same during normal operation. When access to the normally sealed system is required, the transition cap is unthreaded from the pipe cap, and a transition fitting is installed instead. A drain hose, vent hose, or the like, may be coupled to an access port of the transition fitting and fastened thereto for passing fluids to or from the normally sealed system. Alternatively, a test instrument may be coupled to the access port. Thereafter, the transition fitting is removed, and the transition cap is re-installed.

Disclosed are an electrical penetration assembly, a manufacturing method thereof, and an electrical penetration device, which relate to the technical field of electrical penetration. The electrical penetration assembly comprises sealing glass (5), an outer tube (4) and a conductor (7) inserted into the outer tube (4), wherein both ends of the outer tube (4) are blocked by supporting and fixing blocks (8), and both ends of the conductor (7) respectively protrude from the corresponding supporting and fixing blocks (8); the sealing glass (5) is sintered between the conductor (7) and the outer tube (4) and is configured to divide an annular cavity jointly enclosed by the conductor (7), the outer tube (4) and the supporting and fixing blocks (8) into an upper cavity and a lower cavity; an optical fiber (14) penetrates the sealing glass (5), at least one end of the optical fiber (14) is connected to an optical fiber splice (3) after protruding from the corresponding supporting and fixing block (8), and a portion of the optical fiber (14) located in the sealing glass (5) is inscribed with a fiber Bragg grating to form a first fiber Bragg grating sensor (1). By utilizing the first fiber Bragg grating sensor (1) to monitor the strain and temperature of the sealing glass (5) in real time, not only can it judge whether the electrical penetration assembly meets the requirements for hermeticity, but also enable precise control of the sintering temperature.

Nuclear power plant (NPP) containment building separation system dividing the NPP containment building into isolated containment building rooms. The system includes containment building separation shutters located in the circular gap which divides the containment building rooms and the containment building walls; an air supply unit connected to a manifold ring which, in turn, is connected to the air-inflated shutters designed to ensure insulation of the airspace inside the containment building rooms when inflated and to connect the airspace when deflated. In emergency mode the air supply to the air-inflated shutters is terminated, and the shutters get deflated and fully open the circular gap which ensures convection process throughout the whole area of containment building.

The fuel cartridge may include a plurality of fuel channels, a first header disposed on a first side of a fuel matrix, a second header disposed on a second side of the fuel matrix opposite to the first side, and a plurality of cooling tubes through which a working fluid flows. Each of the plurality of cooling tubes may pass through each corresponding cooling channel of the plurality of cooling channels, where each of the plurality of cooling tubes has a first end connected to the first header and a second end connected to the second header. The fuel cartridge may include an interior space for sealingly containing the fuel matrix may include a pressure boundary independent from an interior of the plurality of cooling tubes, such that the interior space is not in fluid communication with the plurality of cooling tubes.

The fuel cartridge may include a plurality of fuel channels, a first header disposed on a first side of a fuel matrix, a second header disposed on a second side of the fuel matrix opposite to the first side, and a plurality of cooling tubes through which a working fluid flows. Each of the plurality of cooling tubes may pass through each corresponding cooling channel of the plurality of cooling channels, where each of the plurality of cooling tubes has a first end connected to the first header and a second end connected to the second header. The fuel cartridge may include an interior space for sealingly containing the fuel matrix may include a pressure boundary independent from an interior of the plurality of cooling tubes, such that the interior space is not in fluid communication with the plurality of cooling tubes.

Disclosed are a nuclear reactor long-term cooling system and a nuclear plant having the same. The nuclear reactor long-term cooling system, comprises: a lower containment area formed to enclose a reactor coolant system, and configured to prevent steam containing radioactive substances generated from the reactor coolant system from leaking to a path other than a discharge unit; an In-Containment Refueling Water Storage Tank (IRWST) disposed outside the lower containment area, and having refueling water stored therein; and a discharge pipe configured to connect the lower containment area to the IRWST, and to discharge steam of the lower containment area to the refueling water when an accident occurs. The nuclear plant may have an enhanced safety.