In view of above problems, an object of the invention is to provide a primary containment vessel venting system having a structure capable of continuously discharging vapor in a primary containment vessel out of the system and continuously reducing pressure of the primary containment vessel without discharging radioactive noble gases to the outside of the containment vessel and without using an enclosing vessel or a power source. In order to achieve the above object, an nuclear power plant of the invention includes a primary containment vessel which includes a reactor pressure vessel, a radioactive substance separation apparatus which is disposed inside the primary containment vessel and through which the radioactive noble gases do not permeate but vapor permeates, a vent pipe which is connected to the radioactive substance separation apparatus, and an exhaust tower which is connected to the vent pipe and discharges a gas, from which a radioactive substance is removed, to the outside.

In view of above problems, an object of the invention is to provide a primary containment vessel venting system having a structure capable of continuously discharging vapor in a primary containment vessel out of the system and continuously reducing pressure of the primary containment vessel without discharging radioactive noble gases to the outside of the containment vessel and without using an enclosing vessel or a power source. In order to achieve the above object, an nuclear power plant of the invention includes a primary containment vessel which includes a reactor pressure vessel, a radioactive substance separation apparatus which is disposed inside the primary containment vessel and through which the radioactive noble gases do not permeate but vapor permeates, a vent pipe which is connected to the radioactive substance separation apparatus, and an exhaust tower which is connected to the vent pipe and discharges a gas, from which a radioactive substance is removed, to the outside.

The disclosure describes hydrocarbon flowline corrosion inhibitor overpressure protection. Such a protection system includes a fluid flow pathway fluidically coupled to a corrosion inhibitor injection pump that injections corrosion inhibitor into a hydrocarbon carrying flowline. When the injection pump pressure exceeds a threshold flow pressure, the corrosion inhibitor is flowed through a first branch of the fluid flow pathway to relieve the excess pressure. The first branch is fluidically isolated from a second branch. When a rupture disc in the first branch fails, then the corrosion inhibitor is diverted to flow through the second branch and the first branch is isolated from the corrosion inhibitor flow.

The invention relates to a rupture disc for a device for protecting against overpressures inside an apparatus, the disc consisting of a generally circular part including two planar surfaces substantially parallel to one another, and two notches each located along a circumference, the circumferences of the two notches being different from one another, the notch located on the larger circumference being made on one of the planar surfaces, referred to as lower surface, while the notch located on the smaller circumference is made on the other one of the planar surfaces, referred to as upper surface.

The disclosure describes hydrocarbon flowline corrosion inhibitor overpressure protection. Such a protection system includes a fluid flow pathway fluidically coupled to a corrosion inhibitor injection pump that injections corrosion inhibitor into a hydrocarbon carrying flowline. When the injection pump pressure exceeds a threshold flow pressure, the corrosion inhibitor is flowed through a first branch of the fluid flow pathway to relieve the excess pressure. The first branch is fluidically isolated from a second branch. When a rupture disc in the first branch fails, then the corrosion inhibitor is diverted to flow through the second branch and the first branch is isolated from the corrosion inhibitor flow.

A containment vessel has an inner shell covering a reactor pressure vessel and an outer shell forming an outer well which is a gas-tight space covering the horizontal outer periphery of the inner shell. The inner shell has a first cylindrical side wall surrounding the horizontal periphery of the reactor pressure vessel, a containment vessel head which covers the upper part of the reactor pressure vessel, and a first top slab connecting in a gas-tight manner the periphery of the containment vessel head and the upper end of the first cylindrical side wall. The outer shell has a second cylindrical side wall surrounding the outer periphery of the first cylindrical side wall, and also has a second to slab connecting in a gas-tight manner the vicinity of the upper end of the second cylindrical side wall and the first cylindrical side wall.

A containment vessel has an inner shell covering a reactor pressure vessel and an outer shell forming an outer well which is a gas-tight space covering the horizontal outer periphery of the inner shell. The inner shell has a first cylindrical side wall surrounding the horizontal periphery of the reactor pressure vessel, a containment vessel head which covers the upper part of the reactor pressure vessel, and a first top slab connecting in a gas-tight manner the periphery of the containment vessel head and the upper end of the first cylindrical side wall. The outer shell has a second cylindrical side wall surrounding the outer periphery of the first cylindrical side wall, and also has a second to slab connecting in a gas-tight manner the vicinity of the upper end of the second cylindrical side wall and the first cylindrical side wall.

Simplified nuclear reactors include depressurization systems or gravity-driven injection systems or both. The systems depressurize and cool the reactor without operator intervention and power. An underground containment building may be used with the depressurization and injection systems passing through the same from above ground. Depressurization systems may use a rupture disk, relief line, pool, and filter to open the reactor and carry coolant away for condensation and exhausting. Injection systems may use a coolant tank above the nuclear reactor to inject liquid coolant by gravity into the reactor through an injection line and valve. The rupture disk and valve may be integral with the reactor and use penetration seals where systems pass through containment. Rupture disks and valves can actuate passively, at a pressure setpoint or other condition, through fluidic controls, setpoint failure, etc. The depressurization system and injection system together feed-and-bleed coolant through the reactor.

Simplified nuclear reactors include depressurization systems or gravity-driven injection systems or both. The systems depressurize and cool the reactor without operator intervention and power. An underground containment building may be used with the depressurization and injection systems passing through the same from above ground. Depressurization systems may use a rupture disk, relief line, pool, and filter to open the reactor and carry coolant away for condensation and exhausting. Injection systems may use a coolant tank above the nuclear reactor to inject liquid coolant by gravity into the reactor through an injection line and valve. The rupture disk and valve may be integral with the reactor and use penetration seals where systems pass through containment. Rupture disks and valves can actuate passively, at a pressure setpoint or other condition, through fluidic controls, setpoint failure, etc. The depressurization system and injection system together feed-and-bleed coolant through the reactor.

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.