A main pump shaft seal water injection system of a nuclear power plant includes a jet pump, a high pressure cooler, a hydrocyclone, valves and a main connection pipeline outside of a main pump, and an auxiliary pump and an internal flow path inside the main pump. Inner and outer flow paths of the main pump are connected with a shaft seal water injection hole and a high temperature water drainage hole. The main connection pipeline is connected between an upper filling water pipeline and a shaft seal water injection hole. A bypass pipeline connected with the jet pump, the high pressure cooler and the hydrocyclone, the main connection pipeline is provided with a normally open main pipeline isolating valve. The bypass pipeline allows low temperature upper filling water in the RCV system to enter the shaft seal water injection hole of the main flange directly.

A main pump shaft seal water injection system of a nuclear power plant includes a jet pump, a high pressure cooler, a hydrocyclone, valves and a main connection pipeline outside of a main pump, and an auxiliary pump and an internal flow path inside the main pump. Inner and outer flow paths of the main pump are connected with a shaft seal water injection hole and a high temperature water drainage hole. The main connection pipeline is connected between an upper filling water pipeline and a shaft seal water injection hole. A bypass pipeline connected with the jet pump, the high pressure cooler and the hydrocyclone, the main connection pipeline is provided with a normally open main pipeline isolating valve. The bypass pipeline allows low temperature upper filling water in the RCV system to enter the shaft seal water injection hole of the main flange directly.

An auxiliary system for cooling a spent nuclear fuel pool through a submersible heat exchanger to be located within the pool. In each train or installation, a single loop or series of loops of cooling fluid (e.g., sea water or service water) is circulated. The system is modular, readily and easily installed during an emergency and can be self operating with its own power source. Multiple trains may be used in parallel in order to accomplish the required degree of spent fuel pool cooling required.

An auxiliary system for cooling a spent nuclear fuel pool through a submersible heat exchanger to be located within the pool. In each train or installation, a single loop or series of loops of cooling fluid (e.g., sea water or service water) is circulated. The system is modular, readily and easily installed during an emergency and can be self operating with its own power source. Multiple trains may be used in parallel in order to accomplish the required degree of spent fuel pool cooling required.

Systems and methods for upgrading power output of previously-deployed nuclear power plants are described. Systems and methods may include a base nuclear power plant with a predetermined base power output rating and a predetermined base whole core refueling interval. Systems and methods may also include a power upgrade kit for increasing the base power output rating from the base power output rating to an increased power output rating without a change in fuel charge, reactor structures, or civil structures.

Systems and methods for upgrading power output of previously-deployed nuclear power plants are described. Systems and methods may include a base nuclear power plant with a predetermined base power output rating and a predetermined base whole core refueling interval. Systems and methods may also include a power upgrade kit for increasing the base power output rating from the base power output rating to an increased power output rating without a change in fuel charge, reactor structures, or civil structures.

The method estimates the damaging dose of fast neutrons (dpa) which results in unacceptable degradation of paste-forming properties of steel. Upon achievement of the reactor energy yield, the direction of the coolant flow is changed from the standard direction to the reverse direction. Then an acceptable period of time is set for the annealing of reactor core elements. The temperature of the annealing mode is set and maintained by controlling the power level sufficiently to restore paste-forming properties of steel of the lower core section within the set period of time. At the end of the pre-set annealing period, the direction of the coolant flow is changed from reverse to the standard one.

A component cooling water system for a nuclear power plant. In one embodiment, the system includes an inner containment vessel housing a nuclear reactor and an outer containment enclosure structure. An annular water reservoir is formed between the containment vessel and containment enclosure structure which provides a heat sink for dissipating thermal energy. A shell-less heat exchanger is provided having an exposed tube bundle immersed in water held within the annular water reservoir. Component cooling water from the plant flows through the tube bundle and is cooled by transferring heat to the annular water reservoir. In one non-limiting embodiment, the tube bundle may be U-shaped.

The present invention relates to filters used to remove debris from water being sucked into a piping system. It has particular application for use in nuclear power plants, which, after a loss of coolant accident, must pump cooling water back into the reactor core from a collection sump. This water may contain various types of debris that must be removed before the water is sent back into the reactor cooling system. Filtering of the debris is realized with the component known as “strainers”. There are restrictions on the space available for installing strainers. The vaned filtering element, for example a vaned fin, of the present invention is designed to reduce the space required for strainer installation by increasing strainer surface area per unit volume, while maximizing the quantity of debris that can be filtered from the water.

The present invention relates to filters used to remove debris from water being sucked into a piping system. It has particular application for use in nuclear power plants, which, after a loss of coolant accident, must pump cooling water back into the reactor core from a collection sump. This water may contain various types of debris that must be removed before the water is sent back into the reactor cooling system. Filtering of the debris is realized with the component known as “strainers”. There are restrictions on the space available for installing strainers. The vaned filtering element, for example a vaned fin, of the present invention is designed to reduce the space required for strainer installation by increasing strainer surface area per unit volume, while maximizing the quantity of debris that can be filtered from the water.