A method for complex-decommissioning a nuclear facility is disclosed. The method for complex-decommissioning the nuclear facility includes: cutting and expanding an inner wall of the cavity; installing a cutting device that cuts and decommissions the nuclear reactor pressure vessel inside the cavity; fixing the nuclear reactor pressure vessel inside the cavity by using a fixture; and cutting and decommissioning the nuclear reactor pressure vessel fixed inside the cavity by using a cutting device.

A data-based nuclear power plant design basis management system and a method therefor are disclosed. According to an embodiment of the present invention, the data-based nuclear power plant design basis management system comprises a database for storing: information on a plurality of design basis for defining a design basis document for configuration management in a nuclear power plant; information on a category, corresponding to each of the design basis, among a plurality of categories; and an associative relationship between the plurality of design basis, wherein the plurality of categories includes design requirements (REQ), at least one design basis specification (DBS) for satisfying the REQ, and the like.

A data-based nuclear power plant design basis management system and a method therefor are disclosed. According to an embodiment of the present invention, the data-based nuclear power plant design basis management system comprises a database for storing: information on a plurality of design basis for defining a design basis document for configuration management in a nuclear power plant; information on a category, corresponding to each of the design basis, among a plurality of categories; and an associative relationship between the plurality of design basis, wherein the plurality of categories includes design requirements (REQ), at least one design basis specification (DBS) for satisfying the REQ, and the like.

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.

A method of fragmentation of elements of a nuclear reactor includes placement of elements inside a cask and subsequent cutting, the cask being perforated. Each element is lowered into the cask by a full internal height of the cask using a gripper having clamping jaws. The element is intercepted at an upper edge of the cask, lifted, and positioned using video surveillance and artificial lighting so that a hydraulic cutter is directly under the clamping jaws. The element is cut at a point corresponding to a level of the upper edge of the cask, separating from the element a fragment equal to the internal height of the cask. Then the upper part of the element remaining after cutting is lowered inside the cask by the full internal height of the cask and the cutting of the element into fragments is repeated until the element is fully cut to fragments.

The invention relates to an arrangement for dismantling a container (10) which comprises a circumferential wall (20) and an opening surrounded by said wall and which has a screening cover (14) situated above the opening, and to a dismantling tool for cutting segments (42, 44, 46, 53, 56) out of the circumferential wall. The dismantling takes place in such a way that regions of the circumferential wall which have a hollow cylindrical geometry are successively cut into segments and these segments are then removed. After a segmented region having the hollow cylindrical ring geometry has been removed, an end edge of the remaining circumferential wall is available. The screening cover has a lowering device for successively lowering the screening cover onto a particular available end edge.

An underground nuclear power reactor having a hollow blast tunnel which extends from one end of a containment member which houses a nuclear reactor, heat exchanger, generator, etc. A hollow blast tunnel extends from one end of the containment member with a normally closed door positioned therebetween. The blast tunnel defines a blast chamber having a plurality of spaced-apart debris deflectors positioned therein. The blast chamber has an upper wall with a roof opening formed therein which is selectively closed by a roof portion. If the reactor needs to be repaired or replaced, the door is opened so that the reactor will pass therethrough into the blast chamber and outwardly through the roof opening. If the reactor explodes, the blast therefrom drives the debris therefrom through the door and into the blast chamber where the deflectors reduce the blast force as the debris passes through the blast chamber.

An external reactor vessel cooling and electric power generation system according to the present invention includes an external reactor vessel cooling section formed to enclose at least part of a reactor vessel with small-scale facilities so as to cool heat discharged from the reactor vessel, a power production section including a small turbine and a small generator to generate electric energy using a fluid that receives heat from the external reactor vessel cooling section, a condensation heat exchange section 140 to perform a heat exchange of the fluid discharged after operating the small turbine, and condense the fluid to generate condensed water, and a condensed water storage section to collect therein the condensed water generated in the condensation heat exchange section, wherein the fluid is phase-changed into gas by the heat received from the reactor vessel. The external reactor vessel cooling and electric power generation system according to the present invention can continuously operate even during an accident as well as during a normal operation to cool the reactor vessel and produce emergency power, thereby enhancing system reliability. The external reactor vessel cooling and electric power generation system according to the present invention can easily apply safety class or seismic design using small-scale facilities, and its reliability can be improved owing to applying the safety class or seismic design.

An apparatus for decommissioning heavy-water reactor facilities includes a shielding device including a drawing-out space that is mounted on the reactivity mechanism deck and communicates with one through-hole among the plurality of through-holes, a separating device that is inserted into the inside of one of the plurality of guide tubes through the drawing-out space and the one through-hole and cuts an end portion of the one guide tube connected to the calandria, and a drawing-out device that is inserted into the inside of the one guide tube through the drawing-out space and the one through-hole and supports the end portion of the one guide tube to draw out the one guide tube into the inside of the drawing-out space through the one through-hole.

Disclosed is an Offshore Energy Generation System (OEGS), zero greenhouse gases emissions during operations, earthquake and tsunami proof, nuclear meltdown safe, floating ship-shaped, moored. The INVENTION delivers clean energy in the form of electricity and/or ammonia (NH.sub.3) and freshwater to offshore or onshore consumers. The INVENTION is effective, affordable and reliable solution for the global climate change and the freshwater scarcity crisis. By deploying this INVENTION across the world, the net zero emissions targets from IPCC can be achieved and the water scarcity crisis mitigated. The INVENTION enables better safety of the population served, optimal use of land, eliminate land use conflicts and enables the protection of the world cultural heritage. The INVENTION comprises of an electric power generation system based on nuclear or hydrogen (H.sub.2) fuel cells, ammonia generation, freshwater generation, offshore cranes, data processing centers, blockchain, helideck, telecommunications system, automation and control system, nitrogen and hydrogen generation systems.