Hydrogen explosion safety in premises of the containment dome (CNT) at nuclear power plants (NPP) with water-cooled power reactor (VVER). The method for ensuring hydrogen explosion safety at nuclear power plants comprises ventilation of premises of the nuclear reactor premises and hydrogen recombination in premises of the nuclear reactor premises by its catalytic oxidation. In accordance with the declared solution, a reflector is placed on the way of potentially emergency propagation of a pressure hydrogen-containing steam-gas jet, apertures are made in the walls between premises of the nuclear reactor containment dome with a size equal to minimum 35% of the surface area of the said walls, while excess heat is withdrawn in areas of potential localization of hydrogen-containing steam-gas mixture burning sources.

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.

A Stirling engine provides a means to use the thermal energy in the sealed containment environment of a nuclear reactor building to provide emergency cooling. Acting as the prime mover in a coupled heat exchanger system, a Stirling engine could develop fluid flow thereby resulting in forced convection vice natural circulation and would not rely on an external power source during an unusual accident event where no electric power is available.

A nuclear power reactor which includes passive cooling and radiation scrubbing. The reactor includes a first containment member which is buried in the ground. A second containment member is positioned in the first containment member and has a reactor vessel therein. The discharge side of the reactor vessel is connected to a heat exchanger which drives a turbine which drives a device such as a generator. A source of water is provided which gravity feeds cooling water to the interior of the first containment member in the event of reactor overheating or over-pressurization. A radiation scrubber is provided for scrubbing radiation which may be in the first containment member or the second containment member.

The invention relates to a nuclear power plant including a containment vessel including a reactor pressure vessel for receiving fissionable nuclear fuel, an aerosol filter stage a pressure relief conduit through which a gas volume flow which is filtered in the aerosol filter stage is releasable to ambient through a pass through opening in the containment vessel, and an iodine filter stage through which the gas volume flow that is filtered in the aerosol filter stage is filterable before being released to the ambient, wherein the iodine filter stage is arranged within the containment vessel, characterized in that the aerosol filter stage and the iodine filter stage are connected with one another so that transferring the gas volume flow from the aerosol filter stage to the iodine filter stage is performed essentially at an identical pressure level.

A nuclear system, in particular a nuclear power plant (2), includes a containment (4) and an associated venting system (6), which has a venting line (8) connected to the containment (4), and an emission monitoring system (16) is provided for the venting system (6). A representative measuring sample is taken from the clean gas line of the venting system, and can be tested for aerosol-type decomposition products online in a subsequent analysis system. The emission monitoring system comprises a sampling line (44) for a sample flow branching off from the venting line (8) and leading into a sample container (32), and a recirculation line (54) leading from the sample container (32) to the venting line (8). The sample container (32) contains a wet scrubber (34) for the sample flow, as well as an ionisation separator (64) downstream of the wet scrubber (34) in relation to the sample flow. A liquid removal line (78) leads from the sample container (32) to an analysis unit (20).

Damper systems selectively reduce coolant fluid flow in nuclear reactor passive cooling systems, including related RVACS. Systems include a damper that blocks the flow in a coolant conduit and is moveable to open, closed, and intermediate positions. The damper blocks the coolant flow when closed to prevent heat loss, vibration, and development of large temperature gradients, and the damper passively opens, to allow full coolant flow, at failure and in transient scenarios. The damper may be moveable by an attachment extending into the coolant channel that holds the damper in a closed position. When a transient occurs, the resulting loss of power and/or overheat causes the attachment to stop holding the damper, which may be driven by gravity, pressure, a spring, or other passive structure into the open position for full coolant flow. A power source and temperature-dependent switch may detect and stop holding the damper closed in such scenarios.

A method of releasing an atmospheric effluent within a nuclear containment to an atmosphere surrounding the nuclear containment is disclosed. The nuclear containment is adjacent to an associated spent fuel pool that is located outside the nuclear containment, the method comprises sensing a pressure buildup within the nuclear containment, routing a portion of the atmospheric effluent through the spent fuel pool when a pressure buildup within the nuclear containment reaches a preselected value, and releasing a chemical into the spent fuel pool, based on the routing, to facilitate a reaction with the atmospheric effluent to substantially neuter any deleterious environmental impact of the atmospheric effluent.

A dry FCVS for a nuclear reactor containment is provided. The dry FCVS includes a housing and a round and/or elongated aerosol filter inside the housing for removing contaminant aerosols from gas passing through the housing during venting of the containment. The housing includes at least one inlet portion configured for directing gas into the aerosol filter during the venting of the containment and an outlet portion for gas filtered by the aerosol filter during the venting of the containment. The dry filtered containment venting system is arranged and configured such that when a flow of gas through the outlet portion is closed off at least one of convective, radiant and conductive heat transfer removes decay heat of aerosols captured in the aerosol filter.

The invention provides a reactor containment vessel vent system capable of continuously releasing steam generated in a reactor containment vessel to the atmosphere even when a power supply is lost. In the reactor containment vessel vent system (15), the noble gas filter (23) that allows steam to pass through but does not allow radioactive noble gases to pass through among vent gas discharged from the reactor containment vessel (1) is provided at a most downstream portion of the vent line. An immediate upstream portion of the noble gas filter (23) and the reactor containment vessel (1) are connected to each other by the return pipe (24a, 24b) via the intermediate vessel (100). Further, when the radioactive noble gases having pressure equal to or higher than predetermined pressure stays in the immediate upstream portion of the noble gas filter (23), the staying radioactive noble gases flows into the intermediate vessel (100) by the relief valve (25). Thus, the noble gas filter (23) does not lose steam permeability, and the reactor containment vessel vent system (15) can continuously release the steam to the atmosphere.