A system is provided for use with a nuclear reactor which is mounted on a barge and which floats in a water tank. The system includes at least one water pipe which extends from a source of water to the interior of the tank. The system also includes a pipe which permits the drainage of water from the water tank. Valves are imposed in the piping so that the water in the tank will have a desired level and temperature. The system also enables fresh water to be supplied to the containment interior of the reactor. Further, the system includes piping and valves to supply water to the condenser and to drain water from the condenser. The system also includes flexible and slack tubular sections positioned in the piping between the barge and the water tank which allows the barge to move while maintaining the integrity of the tubing.

A method for heating primary coolant in a nuclear supply system in one embodiment includes filling a primary coolant loop within a reactor vessel and a steam generating vessel that are fluidly coupled together with a primary coolant, drawing a portion of the primary coolant from the primary coolant loop and into a start-up sub-system, heating the portion of the primary coolant to form a heated portion of the primary coolant, and injecting the heated portion of the primary coolant back into the primary coolant loop. The primary coolant may be heated to a no-load operating temperature.

The steam generating unit of dual circuit reactor with blowdown and drain system is implemented in the close loop, without any conventional blowdown expansion tanks and is designed for maximum pressure of the steam generator (SG) working medium. The SG blowdown water is combined into a single line, cooled down in the regenerative heat exchanger, then in the blowdown aftercooler and drain cooling line and taken out of the tight shell. Out of the tight shell, the SG blowdown water is supplied for treatment to the SG blowdown water treatment system designed for maximum pressure of the steam generator (SG) working medium. After treatment, the water returns to the tight shell and, via the regenerative heat exchanger, to the feed pipelines of each SG. The invention provides increased SG blowdown that leads to the accelerated chemical condition normalization even with considerable deviations.

A decommissioning method of biodegradable concrete of a nuclear power plant according to an exemplary embodiment includes: decommissioning a neutron detector positioning device installed to biodegradable concrete surrounding a nuclear reactor to form a plurality of penetrated parts in the biodegradable concrete; inserting a part of a cutting device into the plurality of penetrated parts; and decomposing the biodegradable concrete into a plurality of sub-concrete parts by using the cutting device.

A method for decommissioning a nuclear facility includes: separating a nuclear reactor pressure vessel from biodegradable concrete; decommissioning a concrete structure; covering the biodegradable concrete; and decommissioning the biodegradable concrete.

A method of decommissioning a nuclear facility, including: exposing the plurality of upper penetration holes by removing the plurality of sandboxes; enlarging an upper space of the cavity by cutting an upper portion of the biological shield concrete that is disposed between the plurality of upper penetration holes and between the plurality of upper penetration holes and the cavity; and separating the nuclear reactor pressure vessel from the biological shield concrete.

A method of decommissioning a nuclear facility including a plurality of sandboxes that cover a plurality of upper penetration holes, includes: exposing the plurality of pipes through the plurality of upper penetration holes by removing the plurality of sandboxes; and cutting the plurality of pipes through the plurality of upper penetration holes.

Disclosed herein is a machine for cutting nozzles of reactor vessels. The machine for cutting nozzles of reactor vessels comprises a cutting unit positioned at an upper surface edge of a reactor vessel having a nozzle and having a saw blade part having different contact areas to cut the nozzle, a drive unit providing the saw blade part with rotary power, and a foreign substance suction unit provided at one end of the cutting unit in contiguity with the saw blade part to suck foreign substances generated when the nozzle is cut by the saw blade part, wherein the foreign substance suction unit sucks the foreign substances by approaching an outer peripheral surface of the nozzle when the saw blade part moves in a cutting direction of the nozzle.

The systems and methods generally include a nuclear power plant unit assembled in a shipyard from a plurality of structural modules, each of the structural modules having manufactured components for use in power production when moored or fixed to a floor at least one of in and proximal to at least one of an offshore marine environment, a river environment and a coastal marine environment. The nuclear power plant unit is subdivided into at least one arrangement of structural modules that includes an electrical interface for one of transmitting electrical power generated by the nuclear unit and powering a system of the unit, a communications interface for communications internal or external to the unit, a user interface that is configured to permit a user to access a system of the unit, and a network interface for data communications to or from the unit.

The systems and methods generally include a nuclear power plant unit assembled in a shipyard from a plurality of structural modules, each of the structural modules having manufactured components for use in power production when moored or fixed to a floor at least one of in and proximal to at least one of an offshore marine environment, a river environment and a coastal marine environment. The nuclear power plant unit is subdivided into at least one arrangement of structural modules that includes an electrical interface for one of transmitting electrical power generated by the nuclear unit and powering a system of the unit, a communications interface for communications internal or external to the unit, a user interface that is configured to permit a user to access a system of the unit, and a network interface for data communications to or from the unit.