Korea Atomic Energy Research Institute

Korea Hydro Nuclear Power Co., Ltd.

Korea Hydro and Power Co., Ltd.

Chul-Hwa Song

Tae-Soon Kwon

Won-Pil Baek

Seok-Kyu Chang

Hyun Sik Park

Sung-Jae Yi

Sung-Hoon Baik

Seok Chun Cho

Dong Jin Euh

Sung Won Bae

Dong-Jin Euh

Won Pil Baek

Nam Hyun Choi

Rae-Joon Park

In-Cheol Chu

Jun-Hwa Hong

In-Chul Chu

Jong-kyun Park

Provided are a nuclear reactor and an operating method for the reactor. The reactor includes a driving system and a safety system. The safety system includes isolation vessels, heat exchangers, a coolant pipe, and a communication pipe. Fluid is distributed in the safety system according to thermal, pressure, and leak conditions.

Reactor and operating method for the reactor

A high pressure safety injection tank (HPSIT) system includes one safety injection tank (HIT) which replaces a core makeup tank (CMT) and a low pressure (approximately 4.3 Mpa or below) safety injection tank (SIT) and which can shift to and operate on a high pressure (approximately 17 Mpa) operation mode, to enable injection of emergency core coolant into a reactor system both under low pressure (approximately 4.3 Mpa or below) and high pressure (approximately 17 Mpa).

Passive high pressure safety injection tank system (HPSIT) for responding to station blackout (SBO) and loss-of-coolant accidents (LOCA)

The present invention relates to a longitudinally divided emergency core cooling (ECC) duct in order to efficiently inject safety water to core of a pressurized light-water nuclear reactor. The ECC duct includes side supports for preventing the flow-induced vibration in the annular downcomer, and has structural stability while thermally expanding and contracting. A longitudinally divided ECC duct for emergency core cooling water injection of a nuclear reactor is provided on the periphery of a core barrel of a nuclear reactor, includes an emergency core cooling water inlet facing a direct vessel injection nozzle, and extends in a longitudinal direction of the core barrel. The longitudinally divided ECC duct is divided into a plurality of longitudinally-divided ducts in the longitudinal direction of the longitudinally divided ECC duct.

Emergency core cooling duct for emergency core cooling water injection of a nuclear reactor

Disclosed is a laser doppler velocity system that can easily change a focal length of laser beam, in order to measure the velocity of fluid. As the fluid lens is used in order to focus the laser beam, the lens aperture is rapidly and accurately changed at a low power to easily measure the flow-velocity and shear stress of the boundary layer of the structure within the flow field. As the optical array including the fluid lens is integrated using a diode laser as a laser light source, the laser doppler velocity system can be made in small-size. Also, as the laser doppler velocity system is inserted into the surface of the structure, it can be used as a surface flow field measurement sensor.

Laser doppler velocity system for variable beam focusing

A separable ball valve apparatus and ball valve assembly capable of selectively opening/closing a separable flow path are provided. The separable ball valve apparatus comprises a separable pipe member having a flow path through which fluid flows, a ball member having at least two balls disposed in the pipe member, opening and closing the flow path, and adjacent to each other, and an opening/closing member configured to control the ball member to open/close the flow path, wherein the balls have through-holes, respectively, and the opening/closing member includes a gear train configured to control the opening/closing of the at least two balls. Therefore, it is possible to simply open/close pipes having the flow path and detachably attach the pipes, increase space utilization due to removal of a separate coupling space for attachment/detachment of the pipes, and simultaneously open/close the two pipes, which are separated from each other through one operation.

Separable ball valve apparatus and ball valve assembly

An emergency core cooling system directly injects emergency core cooling water, which is supplied from a high-pressure safety injection pump or a safety injection tank for a pressurized light water reactor, into a reactor vessel downcomer. A pipe connector is completely removed from between each direct vessel injection nozzle and each injection extension duct installed on an outer surface of the core barrel, which are opposite to each other. An emergency core cooling water intake port, through which the water is injected from each direct vessel injection nozzle, is formed on the surface of each injection extension duct facing an axis of each direct vessel injection nozzle. Thereby, a structure in which a jet of the emergency core cooling water flows into the injection extension ducts is adopted in a hydraulic connection fashion.

Emergency core cooling system having core barrel injection extension ducts

A safety injection tank, used for quickly injecting emergency core cooling water (ECCW) to a reactor vessel in the case of a cold leg large break accident (CLLBA) in a pressurized water reactor (PWR), is disclosed. The safety injection tank has a gravity-driven fluidic device configured to efficiently change the ECCW injection mode from a high flow injection mode to a low flow injection mode. The gravity-driven fluidic device includes a spring placed in the upper end of the vertical pipe, and a vertically movable water tub placed on the spring so as to be movable in a vertical direction. When ECCW contained in the pressure vessel is discharged and the water level is reduced lower than the height of the tub, the tub is moved downwards such that the lower surface thereof comes into contact with the vertical pipe and closes the high flow inlet port.

Safety injection tank with gravity driven fluidic device

A direct vessel injection (DVI) nozzle for minimum emergency core coolant (ECC) bypass is disclosed. The DVI nozzle is used in a pressurized light water reactor (PLWR) having a reactor vessel with a reactor coolant system in which a coolant flows into the reactor vessel through a cold leg and passes through a reactor core prior to being discharged to the outside of the reactor vessel through a hot leg. The DVI nozzle, provided to directly inject ECC into the reactor vessel to cool the reactor core during a break in the reactor coolant system, such as a cold leg break (CLB) that may occur in the PLWR, is placed on the reactor vessel at a position horizontally offset from the central axis of the hot leg at an angle of 10&#xb0; to 30&#xb0; and is involved within a region defined above the central axis of the hot leg by a distance of 1.5 times the sum of diameters of the hot leg and the DVI nozzle. Thus, the DVI nozzle efficiently injects ECC, and remarkably reduces the direct ECC bypass fraction to a broken cold leg and minimizes the amount of direct ECC bypass.

Direct vessel injection (DVI) nozzle for minimum emergency core cooling (ECC) water bypass

A direct vessel injection-type pressurized light water reactor (DVI-PLWR), in which an emergency core cooling water (ECC) is directly injected into a downcomer of a reactor vessel, is disclosed. In order to reduce the ratio of ECC bypass from the downcomer to a broken area of a cold leg in the case of a cold leg guillotine break (CLGB), such as a double-ended guillo4tine break (DEGB), a plurality of corrugations, having a V-shaped cross-section, are vertically arranged around each of the inner surface of a pressure vessel and the outer surface of a core barrel at regular intervals, with a vertical groove formed between two neighboring corrugations. The grooves phase-separate the ECC from a high-speed lateral flow of fluid running in the downcomer, and the separated ECC stagnates in the form of vortexes in the grooves, prior to flowing down to the lower section of the downcomer due to gravity. The DVI-PLWR thus reduces the ratio of ECC bypass, and a large amount of ECC reaches the reactor core in the case of a large break loss-of-cooling water accident (LBLOCA) caused by DEGB. It is thus possible to limit an increase in the maximum cladding temperature of fuel rods, and to prevent the reactor core from being reheated at the late reflood phase after the DEGB-caused LBLOCA, so that the desired thermal hydraulic safety of the DVI-PLWR is secured.

Growing community of inventors

Daejeon, South Korea

Chul-Hwa Song