A method and apparatus for maintaining or establishing a readiness state in a fuel cell backup system of a nuclear reactor system are disclosed. A method includes maintaining a readiness state of a fuel cell system within a set of readiness parameters, the readiness parameters a function of a characteristic of the nuclear reactor system. Another method includes monitoring a nuclear reactor system characteristic and, responsive to the monitored nuclear reactor system characteristic, establishing a readiness state of a fuel cell system. An apparatus includes a fuel cell system associated with a nuclear reactor system and a fuel cell control system configured to maintain a readiness state of the fuel cell system. Another apparatus includes a fuel cell system associated with a nuclear reactor system, a nuclear reactor characteristic monitoring system, and a fuel cell control system configured to establish a readiness state of the fuel cell system.

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.

Methods for nuclear power plant maintenance which reduces outage time while a polar crane is maintained. In some examples, the method includes the steps of placing an auxiliary crane on a set of rails of a polar crane, using the auxiliary crane to perform maintenance work while the polar crane is maintained, and removing the auxiliary crane after maintenance work on the polar crane is completed. In some further examples, the method includes placing a second auxiliary crane on the set of rails. Still in other example, bridge motors are used to turn the rails, allowing the auxiliary crane to reach every area of the plant floor.

A method of providing an emergency supply of services to a nuclear power plant having a cooling water cycle, the method including: situating a container at a remote location from the power plant, wherein the container has permanently integrated therein: a motor comprising a first shaft and a second shaft; a generator driven by the first shaft; a pump driven by the second shaft; a fuel tank connected to the motor, and supplying fuel to the motor; and a transformer connected to the generator; connecting the pump to the cooling water cycle of the nuclear power plant; using the pump to pump water from an external water feed into the cooling water cycle of the nuclear power plant.

A method of providing an emergency supply of services to a nuclear power plant having a cooling water cycle, the method including: situating a container at a remote location from the power plant, wherein the container has permanently integrated therein: a motor comprising a first shaft and a second shaft; a generator driven by the first shaft; a pump driven by the second shaft; a fuel tank connected to the motor, and supplying fuel to the motor; and a transformer connected to the generator; connecting the pump to the cooling water cycle of the nuclear power plant; using the pump to pump water from an external water feed into the cooling water cycle of the nuclear power plant.

A pressurized water reactor (PWR) includes a cylindrical pressure vessel defining a sealed volume, a nuclear reactor core disposed in a lower portion of the cylindrical pressure vessel, one or more control rod drive mechanisms (CRDMs) disposed in the cylindrical pressure vessel above the nuclear reactor core, and an annular steam generator surrounding the nuclear reactor core and the CRDM. In some such PWR, a cylindrical riser is disposed coaxially inside the pressure vessel and inside the annular steam generator and surrounds the nuclear reactor core and the CRDM, and the steam generator is disposed coaxially inside the cylindrical pressure vessel in an annular volume defined by the cylindrical pressure vessel and the cylindrical riser. In other such PWR, the steam generator is disposed coaxially outside of and secured with the cylindrical pressure vessel.

A method for controlling water chemistry in a power generation plant including a low-pressure feedwater heater (18), a deaerator (19), and a high-pressure feedwater heater (20) disposed sequentially along a feedwater pipe (16) from a condenser (15) to a steam generator or a boiler (11) to control the chemistry of feedwater guided to the steam generator or the boiler includes the steps of: injecting an oxidant through an oxidant injection line (31) into feedwater flowing through the feedwater pipe disposed downstream of the condenser in such a way that a dissolved oxygen concentration in the feedwater ranges from 3 to 100 ppb while the feedwater is maintained to be neutral to form an oxide film on surfaces of the feedwater pipe, the low-pressure feedwater heater, the deaerator, the high-pressure feedwater heater, and other structural members that come into contact with the feedwater; and injecting a deoxidant through a deoxidant injection line (35) into the feedwater flowing through the feedwater pipe disposed downstream of the deaerator in such a way that the dissolved oxygen concentration in the feedwater flowing into the steam generator or the boiler lowers to 5 ppb or lower.

A method for controlling water chemistry in a power generation plant including a low-pressure feedwater heater (18), a deaerator (19), and a high-pressure feedwater heater (20) disposed sequentially along a feedwater pipe (16) from a condenser (15) to a steam generator or a boiler (11) to control the chemistry of feedwater guided to the steam generator or the boiler includes the steps of: injecting an oxidant through an oxidant injection line (31) into feedwater flowing through the feedwater pipe disposed downstream of the condenser in such a way that a dissolved oxygen concentration in the feedwater ranges from 3 to 100 ppb while the feedwater is maintained to be neutral to form an oxide film on surfaces of the feedwater pipe, the low-pressure feedwater heater, the deaerator, the high-pressure feedwater heater, and other structural members that come into contact with the feedwater; and injecting a deoxidant through a deoxidant injection line (35) into the feedwater flowing through the feedwater pipe disposed downstream of the deaerator in such a way that the dissolved oxygen concentration in the feedwater flowing into the steam generator or the boiler lowers to 5 ppb or lower.

A nuclear power plant having a protective superstructure including a first end region configured to cover a nuclear reactor in a containment structure, a second end region opposite the first end region and configured to cover a cooling water pump house, and a central region between the first and second end regions and configured to cover a turbine hall. The superstructure has an oval-shaped plan profile, the oval having a greater degree of curvature at the first end region than at the second end region.

A nuclear reactor is positioned on a barge which floats on the water of a water tank. The water tank includes a bottom wall, first and second end walls and first and second side walls. The bottom wall includes a lower layer of concrete, an intermediate layer of water impervious material positioned on the lower layer of concrete, and an upper layer of concrete positioned on the intermediate layer of water impervious material. Each of the first and second end walls and the first and second side walls includes an outer layer of concrete, an intermediate layer of water impervious material positioned at the inner side of the outer layer of concrete, and an inner layer of concrete material positioned at the inner side of the intermediate layer of water impervious material.