A nuclear reactor includes an internal steam generator and a nuclear core disposed in a containment structure. A condenser is disposed outside the containment structure, and includes a condenser inlet line tapping off a steam line connected to the steam generator outside the containment structure, and a condensate injection line conveying condensate from the condenser to the integral steam generator. Isolation valves are located outside the containment structure on a feedwater line, the steam line, and the condensate injection line. The valves have an operating configuration in which the isolation valves on the feedwater and steam lines are open and the isolation valve on the condensate injection line is closed, and a heat removal configuration in which the isolation valves on the feedwater and steam lines are closed and the isolation valve on the condensate injection line is open.

Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

Apparatuses for reducing or eliminating Type 1 LOCAs in a nuclear reactor vessel. A nuclear reactor including a nuclear reactor core comprising a fissile material, a pressure vessel containing the nuclear reactor core immersed in primary coolant disposed in the pressure vessel, and an isolation valve assembly including, an isolation valve vessel having a single open end with a flange, a spool piece having a first flange secured to a wall of the pressure vessel and a second flange secured to the flange of the isolation valve vessel, a fluid flow line passing through the spool piece to conduct fluid flow into or out of the first flange wherein a portion of the fluid flow line is disposed in the isolation valve vessel, and at least one valve disposed in the isolation valve vessel and operatively connected with the fluid flow line.

A nuclear reactor includes a reactor core comprising fissile material disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor. A containment compartment contains the radiological containment. A heat sink includes a chimney configured to develop an upward-flowing draft in response to heated fluid flowing into a lower portion of the chimney. A fluid conduit is arranged to receive fluid from the containment compartment and to discharge into the chimney. A filter may be provided, with the fluid conduit including a first fluid conduit arranged to receive fluid from the containment compartment and to discharge into an inlet of the filter, and a second fluid conduit arranged to receive fluid from an outlet of the filter and to discharge into the chimney. As the draft is developed passively, there is no need for a blower or pump configured to move fluid through the fluid conduit.

A remote integrated monitoring operation system includes: a unit integrated database for sequentially recording a name of each plant unit, a parameter indicating an event that has occurred in the plant unit, a state of the parameter, and warning classification indicated by the parameter and the state; an inter-unit influence degree evaluation database for recording influence of the event on the other plant unit; a restoration response guidance database for defining a response to the event; a per-unit urgency degree determination section for determining a degree of urgency of each plant unit; an inter-unit influence degree determination section for evaluating a degree of influence of the event on the other plant unit; and a priority determination section for determining priorities between the respective plant units from the degree of urgency and the degree of influence.

A remote integrated monitoring operation system includes: a unit integrated database for sequentially recording a name of each plant unit, a parameter indicating an event that has occurred in the plant unit, a state of the parameter, and warning classification indicated by the parameter and the state; an inter-unit influence degree evaluation database for recording influence of the event on the other plant unit; a restoration response guidance database for defining a response to the event; a per-unit urgency degree determination section for determining a degree of urgency of each plant unit; an inter-unit influence degree determination section for evaluating a degree of influence of the event on the other plant unit; and a priority determination section for determining priorities between the respective plant units from the degree of urgency and the degree of influence.

A method, system, and apparatus for the thermoelectric conversion of nuclear reactor generated heat including thermoelectrically converting gas cooled nuclear reactor generated heat to electrical energy and supplying the electrical energy to an operation system of the nuclear reactor system.

A method, system, and apparatus for the thermal storage of nuclear reactor generated energy including diverting a selected portion of energy from a portion of a nuclear reactor system to an auxiliary thermal reservoir and, responsive to a shutdown event, supplying a portion of the diverted selected portion of energy to an energy conversion system of the nuclear reactor system.

A pressure-containing silo for one or more components on a primary coolant circuit of a nuclear reactor having nuclear fuel assemblies cooled by coolant circulating the primary coolant circuit, the silo defining a release space which, in a loss-of-coolant accident releasing the pressurised coolant water from the one or more components therein, receives and contains the released water and steam, at increasing pressure, formed therefrom; wherein the silo is formed from plural, substantially identical, stacked and joined modular units, each having: a concrete body, a metal liner which lines a surface of the concrete body, and which, when the units are stacked and joined, is sealed edge-to-edge with metal liners of neighbouring units forming an inward-facing, pressure-containing skin surrounding the release space, and plural conduits which, when the units are stacked, align with the conduits of neighbouring units to receive elongate tensioning members for post-stressing the concrete of the bodies.

A nuclear reactor protection system includes a plurality of functionally independent modules, each of the modules configured to receive a plurality of inputs from a nuclear reactor safety system, and logically determine a safety action based at least in part on the plurality of inputs; and one or more nuclear reactor safety actuators communicably coupled to the plurality of functionally independent modules to receive the safety action determination based at least in part on the plurality of inputs.