There is provided an inspection device for inspecting an inner surface of a nozzle provided in a reactor vessel. The inspection device includes: a device frame, an inspection unit provided on the device frame, an inspection unit push-out moving mechanism for pushing out and moving the inspection unit to the inner surface of the nozzle, a rotation moving mechanism for rotating and moving the inspection unit, a calibration test unit arranged on the device frame for calibrating the inspection unit; and a calibration test unit forward/backward moving mechanism for moving the calibration test unit forward or backward in the direction along the central axis with regard to a track where the inspection unit makes push-out movement.

A thermal control system for a reactor pressure vessel comprises a plate having a substantially circular shape that is attached to a wall of the reactor pressure vessel. The plate divides the reactor pressure vessel into an upper reactor pressure vessel region and a lower reactor pressure vessel region. Additionally, the plate is configured to provide a thermal barrier between a pressurized volume located within the upper reactor pressure vessel region and primary coolant located within the lower reactor pressure vessel region. One or more plenums provide a passageway for a plurality of heat transfer tubes to pass through the wall of the reactor pressure vessel. The plurality of heat transfer tubes are connected to the plate.

A construction layout for underground caverns in a nuclear island powerhouse of an underground nuclear power plant, including: two primary caverns accomodating nuclear reactor powerhouses, combined caverns, electric powerhouse caverns, pressure relief caverns, a first primary traffic tunnel, a second primary traffic tunnel, a third primary traffic tunnel, a top adit system, a ground adit system, secondary traffic tunnels, and a side traffic tunnel. Each combined cavern and each electric powerhouse cavern are disposed at two sides of each primary cavern, respectively. Two combined caverns are in end-to-end connection and the arrangement direction of the two combined caverns are in parallel to the connecting line of the medial axes of the two primary caverns. Each pressure relief cavern is disposed between each combined cavern and a corresponding electric powerhouse cavern.

A construction layout for caverns of an underground nuclear power plant, including: two primary caverns accommodating nuclear reactor powerhouses, combined caverns, electric powerhouse caverns, pressure relief caverns, a first primary traffic tunnel, a second primary traffic tunnel, a third primary traffic tunnel, a top adit system, and a ground adit system. Each combined cavern is disposed on one side of each of the two primary caverns. Each electric powerhouse cavern and each pressure relief cavern are disposed on two sides of each of the two primary caverns perpendicular to the longitudinal direction of the mountain. Each electric powerhouse cavern is perpendicular to the longitudinal direction of the mountain. The first primary traffic tunnel and the third primary traffic tunnel are disposed along the longitudinal direction of the mountain on outer sides of the two combined caverns, respectively.

A construction layout for caverns of an underground nuclear power plant, including: two primary caverns accommodating nuclear reactor powerhouses, electric powerhouse caverns, safe powerhouse caverns, auxiliary powerhouse caverns, nuclear fuel powerhouse caverns, connecting powerhouse caverns, a first primary traffic tunnel, a third primary traffic tunnel, a second primary traffic tunnel, a fourth primary traffic tunnel, and a primary steam channel. The electric powerhouse caverns, the safe powerhouse caverns, and the nuclear fuel powerhouse caverns are arranged along the longitudinal direction of the mountain. Each of the safe powerhouse caverns and each of the nuclear fuel powerhouse caverns are disposed on two sides of each of the two primary caverns in the longitudinal direction of the mountain, respectively. Each of the electric powerhouse caverns and each of the safe powerhouse caverns are located on a same side of each the two primary caverns.

The present invention provides an air circulating sleeve device that is provided below a steam generator to prevent thermal deformation of a sliding base that supports the steam generator of a nuclear reactor, the air circulating sleeve device comprising: a through-hole formed at the center of the sliding base; and a sleeve vertically mounted so as to be aligned with the through-hole, wherein thermal deformation of the sliding base is prevented by performing natural cooling by introducing external air below the sliding base into a stagnated air area inside the sliding base and a skirt support through the sleeve, and the skirt support includes at least one vent hole such that the stagnated air area inside the sliding base and the skirt support is exposed to the air outside the skirt support, and natural circulation of air is performed through the vent hole.

A detector signal-processing circuit comprises the following: a current/voltage conversion part that converts the current value of a neutron detector to a voltage value; a variable gain amplification part that performs amplification by a first-step variable gain using a D/A converter; a current level response-use resistance circuit that selects the measurement range in accordance with the voltage value; temperature measurement units for measuring the temperature of the resistance circuit for current level response; a temperature compensation part for commanding gain compensation by the D/A converter on the basis of the measured temperature; and a selective adjustment control part for selective control of the measurement range and adjustment of the variable gain of the variable gain amplification part. Due to this configuration, neutron flux can be measured with high precision while maintaining a constant output precision, before and after switching of the measurement range.

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 container for storing and/or transporting spent nuclear fuel. The container includes a body that defines an internal cavity that holds the spent nuclear fuel and an outer surface. The outer surface has holes formed therein into which trunnions are positioned. The container can be lifted by a lift yoke by coupling the lift yoke to the trunnions. The trunnions may include first and second components such that the first component is slidable in its axial direction relative to the second component when a force that exceeds a threshold acts on the second component. Thus, the second component may be slidable between a protruded state in which a portion of the second component protrudes from the outer surface of the body and a retracted state in which the second component does not protrude from the outer surface of the body.

The present invention relates to a method of separating radioactive elements from a mixture, wherein the mixture is treated with at least one alkanesulfonic acid and at least one further acid, selected from the group consisting of hydrochloric acid, nitric acid, amidosulfonic acid and mixtures thereof and also the use of at least one alkanesulfonic acid and at least one further acid for separating radioactive elements from mixtures comprising these.