A method and a system for monitoring a state of a nuclear power plant capable of reducing a state prediction error of a sensor during startup, full power, shut down operation of a nuclear power plant, and of providing an early warning, without an error alarm includes remotely and automatically diagnosing the state of a sensor, device, system and power plant. The method and comprises: a first layer that compares a sensor measurement value and a device measurement value with predicted values so as to detect anomalies of the sensor and the device; a second layer that classifies a type of the sensor and diagnoses the presence or absence of an anomaly of the sensor on the basis of an anomaly value of the sensor provided from the first layer.

A method for decommissioning a nuclear facility includes: separating a nuclear reactor pressure vessel from biodegradable concrete; decommissioning a concrete structure; covering the biodegradable concrete; and decommissioning the biodegradable concrete.

There is provided a method of tracking a characteristic line, a method and apparatus of calculating core neutron physics, and a computer-readable storage medium. The method of tracking the characteristic line includes: determining, sequentially from the uppermost level to the lowest level, whether an intersection of the sub-model meeting a first preset condition in each of the plurality of levels and the characteristic line segment meets a second preset condition or not; and obtaining an intersection, that meets the second preset condition, of the sub-model meeting the first preset condition in the lowest level and the characteristic line, so as to obtain a segment correspondence between the characteristic line and the material of the core according to the intersection obtained.

The invention relates to a steel for structural components used at elevated temperatures. The steel comprises the following main components (in wt. %): Cr 8.0-14.0 Ni 4.0-14.0 Al 2.5-5.0 C 0.003-0.3 N≤0.06 Mo+W≤4.0 at least one of: Nb 0.01-1.0 Ta 0.01-1.0 Ti 0.01-1.0 Zr 0.01-1.0 Hf 0.01-1.0 Y 0.05-1.0 balance optional elements, Fe and impurities; and the steel composition fulfilling the following condition: Cr(eq)+Ni(eq)≤30; where Cr(eq)=Cr+2Al+1.5(Si+Nb+Ti)+Mo+0.5W; and Ni(eq)=Ni+10(C+N)+0.5(Mn+Cu+Co).

A control assembly (10) for a nuclear reactor includes a reactivity control device (11) comprising a control rod cluster (12) comprising an attaching head (22), and a drive rod (14) comprising an attaching device (16) for attaching the drive rod (14) to the attaching head (22). The attaching device (16) is movable between a connection position and a disconnection position. The drive rod (14) and the attaching device (16) define an axial trough recess (34) forming a sleeve (35). A checking device (13) engages with the reactivity control device (11) comprising a probe rod (36) which is free to move translationally in the sleeve (35) and comprises a lower end (38) abutting the attaching head (22) of the control rod cluster (12).

A device for imaging radiation source in a decommissioning area of a nuclear power plant includes a detecting unit including a plurality of pixels for detecting an X-ray spectrum generated from a decommissioning area of a nuclear power plant, a processing unit connected to the detecting unit and configured to analyze the X-ray spectrum detected from the plurality of pixels and fuse a first element image displaying first pixels from which a first characteristic X-ray energy of a first element, among the plurality of pixels, is detected and a second element image displaying second pixels from which a second characteristic X-ray energy of a second element, among the plurality of pixels, is detected, into a fused image, and a display unit connected to the processing unit and configured to display the fused image corresponding to the decommissioning area.

A condition determination system includes: an operation condition data obtaining unit that obtains operation condition data indicating an operation condition of a facility; and a determination unit that determines, based on the operation condition data, a level of a phenomenon that occurs due to the operation condition of the facility.

A process of producing a fine-grained austenitic stainless steel, the process comprising a step of subjecting a fine-grained austenitic stainless steel comprising: C: 0.15 wt % or less, Si: 1.00 wt % or less, Mn: 2.0 wt % or less, Ni: 6.0 to 14.0 wt %, Cr: 16.0 to 22.0 wt %, and Mo: 3.0 wt % or less, with the balance being Fe and inevitable impurities, and having an average grain size of 10 μm or lower, to an annealing treatment at a temperature from 600° C. to 700° C. for 48 hours or longer.

A sea creature cleaning robot for an intake tunnel for a nuclear power plant includes a frame, cutter assemblies, and walking wheel assemblies; the frame is used for mounting and fixing cutter mounting seats and crawler wheels; the walking wheel assemblies mounted on the frame enable the entire device to normally walk in a tunnel; the cutter assemblies control the height of cutters by means of hydraulic cylinders to make the cutters contact the inner wall of the tunnel, and the hydraulic cylinders drive the saw-toothed cutters to move back and forth to remove sea creatures attached to the inner wall of the tunnel; the cutter assemblies are uniformly distributed on the frame, so as to ensure full coverage of the cleaning range of the cross section of the tunnel. The robot can clean sea creatures in tunnels in place of manual work to significantly improve the cleaning efficiency.

The invention relates to a device for controlling a plurality of nuclear reactors in clusters, comprising, for each reactor, a plurality of sensors for measuring operating parameters as well as a system for controlling the nuclear reactor, the nuclear reactors being grouped into clusters having a cluster head.