1410 results about "Radiation dose" patented technology

The invention discloses a sparse finite angle CBCT reconstruction method and system based on residual diffusion and a storage medium, and the method comprises the steps: carrying out the CBCT sparse finite angle scanning of a to-be-detected target, and obtaining sparse projection data; fDK reconstruction is carried out on the sparse projection data to obtain an initial CBCT image; generating a first optimized CBCT image from the initial CBCT image through an image pre-training network; through the first optimized CBCT image and the sparse projection data, using the trained residual diffusion model to determine a residual image of the to-be-detected target; summing the first optimized CBCT image of the to-be-detected target and the residual image of the to-be-detected target to obtain a second optimized CBCT image of the to-be-detected target, and the second optimized CBCT image is a final CBCT reconstruction image. According to the method, the problems of stripe artifacts and low-contrast tissue annihilation under limited angle scanning are solved, the large-view CBCT reconstruction resolution is improved, and the radiation dose is reduced.

The invention discloses an intelligent nuclear radiation dose real-time monitoring system based on deep learning, and the system comprises the steps: S1, a multi-mode sensing module which is used for outputting radiation intensity data with timestamps, environment image data and geographic space position information; s2, a preprocessing module used for outputting a structured feature sequence; s3, a fusion modeling module which is used for generating a unified fusion feature vector; s4, an end-edge reasoning module which is used for processing the fusion feature vector in stages and generating a nuclear radiation dose prediction result; s5, the task scheduling module is used for dynamically determining whether the reasoning task is executed on the end side or the edge node; s6, an anomaly detection module which is used for determining whether there is an abnormal change of the nuclear radiation dose; and S7, the system control module is used for coordinating the modules. The method has the advantages of being high in environmental adaptability, fast in reasoning response and high in anomaly recognition precision.

The invention relates to the technical field of intelligent evaluation and early warning methods, in particular to a nuclear radiation dose space distribution intelligent evaluation and early warning method and system, and the method comprises the following steps: obtaining multi-source monitoring data which comprises gamma radiation dose, alpha radiation dose and beta radiation dose measuring instrument data; performing fusion and enhancement processing on the multi-source monitoring data to obtain an enhanced radiation monitoring signal; based on the enhanced radiation monitoring signal, high-precision prediction of nuclear radiation dose spatial distribution is carried out through a deep probabilistic neural network model; according to the high-precision prediction result, in combination with a nuclear accident severity level standard, a radiation alert evaluation result and early warning information are generated, short-term radiation fluctuation can be captured, a long-term change trend can be identified, and the understanding ability of the system to a complex radiation field is greatly improved.

The invention provides a radiation field high-precision reconstruction method based on dynamic geometry aggregation, and relates to the technical field of radiation field reconstruction and computational physics crossing. The method comprises the following steps: extracting a corresponding attenuation coefficient as a priori value; generating a Gaussian radiation element at the position of the monitoring point; calculating the radiation intensity of any point in the space; suppressing mutation of attenuation coefficients of adjacent primitives; gathering to a high dose zone or dispersing to a low dose zone; and generating three-dimensional radiation dose rate distribution by adopting a differentiable split rendering pipeline, and calculating the radiation intensity of any query point in real time by outputting a parameterized Gaussian primitive set. Through the dynamic Gaussian primitive aggregation-physical constraint optimization dual-drive reconstruction framework, the radiation field distribution can still be accurately restored under the sparse detector condition, the error is greatly reduced compared with the traditional method, and the calculation efficiency is obviously improved.

A radiation imaging system includes a radiation imaging apparatus and an imaging control apparatus, the radiation imaging apparatus includes a dose detection pixel that detects a dose of radiation irradiated from a radiation source, and the imaging control apparatus controls the radiation imaging apparatus. Before radiation imaging, the imaging control apparatus specifies a position of the dose detection pixel in a region of interest for calculating a dose indicator value of a radiation image, determines a threshold according to the position of the dose detection pixel, and transmits the position of the dose detection pixel and the threshold to the radiation imaging apparatus. The radiation imaging apparatus makes a setting of the position of the dose detection pixel in the region of interest and the threshold transmitted from the imaging control apparatus, and performs imaging based on the setting.

The invention discloses a BNCT dose calculation method, which comprises the following steps: S1, constructing a voxel model, initializing one or more particles in a simulation system, and respectively acquiring the initial position, energy and movement direction of each particle; s2, adaptively selecting a Monte Carlo particle tracking algorithm and a flux counting mode based on the region where the particles are located and the energy of the particles; s3, repeating the step S2 until the particles leave the simulation system or are killed when meeting a truncation condition; and S4, cumulatively calculating dose distribution. Through the BNCT dose calculation method, the Monte Carlo particle transport simulation time is greatly shortened, the BNCT dose calculation efficiency is optimized, and the method is suitable for rapid and high-precision radiation dose simulation under a BNCT complex tissue structure.

The invention relates to the technical field of bone mineral density detection, and discloses a bone mineral density detection method which comprises the following steps: step 1) image acquisition; step 2) image segmentation; 3) reconstructing a three-dimensional surface; 4) reconstructing three-dimensional body distribution; 5) performing calibration calculation; according to the method, the automatic segmentation algorithm, the three-dimensional reconstruction algorithm and the gray density mapping technology based on the Lambert-Beer law are combined, so that the lumbar vertebra bone mineral density is rapidly and accurately detected, and a reliable basis is provided for early diagnosis of osteoporosis; in addition, the method is based on common X-ray images, is low in radiation dose, is lower in equipment cost, is suitable for basic medical institutions and resource-limited regions, and has wide popularization value and application prospect.

The invention relates to the technical field of nuclear emergency decontamination management, and discloses a nuclear emergency decontamination station partition management method and device based on artificial intelligence, and the method comprises the steps: carrying out the three-dimensional laser scanning and data collection of a pollution region, a decontamination region and a clean region of a nuclear emergency decontamination station, and constructing a decontamination station digital twinborn model; according to the digital twin model of the decontamination station, performing multi-dimensional analysis and weight calculation on the polluted area, the decontamination area and the clean area by adopting an analytic hierarchy process to obtain a partition evaluation parameter matrix; inputting the partition evaluation parameter matrix into a deep reinforcement learning network for dynamic optimization calculation to obtain partition management control parameters; and performing decision analysis and threshold judgment on the radiation dose rate data, the pollution range data, the personnel quantity data and the equipment state data according to the partition management control parameters, and generating an emergency disposal control instruction, thereby realizing cooperative linkage of the pollution area, the decontamination area and the clean area, and improving the accuracy and timeliness of emergency disposal.

A radiation imaging system comprising a radiation imaging apparatus configured to detect radiation emitted from a radiation source, and a radiation control apparatus configured to control the radiation source is provided. The radiation imaging apparatus is configured to output dose information, which includes a dose of radiation entering the radiation imaging apparatus and a time at which the dose was detected, to the radiation control apparatus a plurality of times. The radiation control apparatus is configured to set the threshold dose based on a difference between a time included in the dose information from the radiation imaging apparatus and a time at which the radiation control apparatus received the dose information, and control the radiation source to stop radiation irradiation based on the threshold dose.

A dose feedback system provides real-time or near real-time intra-operative radiation dose feedback system to improve and / or ensure that a proper amount of radiation is delivered to a patient by, for example, carriers (e.g., tile carriers). The dose feedback system can be implemented during medical surgeries, operations, procedures, etc. The dose feedback system may allow a medical professional (e.g., surgeon) to more accurately achieve a prescribed radiation of a dosimetric intent or a more detailed dosimetric plan through adjustments to position, dose, quantity, etc. of carriers prior to terminating the medical procedure (e.g., cavity of tumor bed is closed and / or patient is brought out from under anesthesia) at which point adjusting the radiation dose may be difficult or impossible.

The invention discloses a 3DGS-based integrated visual angle synthesis and sparse visual angle CT reconstruction method, which comprises the following steps: establishing an internal and external parameter matrix through X-ray scanning parameters, constructing an initial voxel space and an initialized 3DGS radiation field by combining sparse visual angle projection data and based on an ACUI strategy, modeling anisotropic radiation intensity by utilizing a radiation intensity response function, and reconstructing a 3D visual angle CT model. And generating a virtual projection by adopting volume consistency rendering. And the optimized radiation field is converted into a voxel grid, density contribution is applied to carry out voxel space reconstruction, a reconstructed voxel space is obtained, and a new 3DGS radiation field is generated. And re-rendering the virtual visual angle projection based on the new 3DGS radiation field, performing iterative optimization by using a loss function, and outputting a new visual angle synthetic image and a CT reconstruction body until a preset number of iterations is reached. And an efficient process of one-time training and dual output is realized. The efficiency and precision of X-ray imaging are improved, the radiation dose of a patient is reduced, and meanwhile, a higher-quality imaging solution is provided for medical diagnosis.

The invention discloses a method and a system for determining optimal parameters of an X-ray excited extra-high voltage composite apparatus, and relates to the technical field of extra-high voltage electrical equipment detection. The method comprises the following steps: remotely operating the X-ray machine and calculating partial discharge intensity; for the current irradiation position, the tube voltage and the tube current are gradually adjusted, parameters are dynamically optimized based on the quantitative relation between the partial discharge intensity and the radiation dose rate change rate, and the optimal parameters are recorded; and changing position repetition parameter optimization, and constructing a BP neural network model after data set training optimization so as to predict an optimal irradiation position. The optimized BP neural network adopts an improved sparrow search algorithm to optimize an initial weight and a threshold value, and combines Bayesian to optimize a learning rate and a hidden node number. Accurate optimization of excitation parameters and irradiation positions is achieved, detection accuracy and safety are both considered, the optimal irradiation position positioning efficiency is improved, and the method is suitable for ultra-high voltage GIS detection of different voltage grades.

A computer-implemented method of determining dose delivered by a radiotherapy system to a plurality of locations within a region of patient anatomy includes: during a first time segment of a treatment fraction, causing the radiotherapy system to be in a first machine state; during the first time segment, delivering radiation to the region of patient anatomy; generating a first surface map for the region of patient anatomy based on surface measurements acquired during the first time segment; generating a first modified digital volume of the region based on the first surface map; and for each of the plurality of locations within the region of patient anatomy, determining a first radiation dose that is delivered to the location during the first time segment, wherein the first radiation dose is based on the first machine state of the radiotherapy system and the first modified digital volume.

The invention provides a deep reinforcement learning kernel emergency robot path planning method introducing a dose factor, and relates to the technical field of robot path planning, the method takes a deep reinforcement learning algorithm as a basis, utilizes an A * algorithm heuristic function, introduces an accumulated radiation dose operator and a distance operator, and obtains the path planning result of the deep reinforcement learning kernel emergency robot. Training to obtain a target network applied to radiation environment path planning; and by using the target network, when the radiation dose and the obstacle are dynamically changed, completing adaptive adjustment of the path of the nuclear emergency robot. According to the method, the interaction capability of the nuclear emergency robot with the environment in the operation process is enhanced, a collision-free self-adaptive operation path with small radiation risk is provided for the nuclear emergency robot, and support is provided for emergency decision making of the nuclear emergency robot.

The invention relates to the technical field of radiotherapy dose prediction, in particular to a glioma radiation dose prediction system based on an attention-enhanced convolutional neural network, which comprises a data collection module, a data preprocessing module, a convolutional neural network module, an attention mechanism module and an output layer. According to the invention, by introducing the attention mechanism, the important feature region can be effectively highlighted, so that the prediction accuracy of the radiation dose of the glioma patient is improved, and the individuation and precision of the treatment scheme are ensured; a dose distribution result can be quickly generated through automatic dose prediction, time and energy investment of doctors in radiotherapy plan design is reduced, working efficiency is improved, accuracy and efficiency of glioma radiotherapy are remarkably improved, clinical decisions are optimized, medical cost is reduced, and support is provided for intelligentization and automation of radiotherapy. Through the research of the project, the application of the deep learning technology in the field of medical image analysis is promoted, and the overall level of radiotherapy is improved.

A quadruped robot with multimodal capabilities and embodied large-scale models for use in a 5G nuclear power plant, characterized in that it comprises: a control module, a power module, a robot arm module, a power supply module, a sensor module, a heat sink, an audio module and a housing structure, wherein the control module, the power module, the robot arm module, the power supply module, the sensor module, the heat sink and the audio module are mounted on the housing structure, wherein the control module is respectively connected to the individual modules, iethe power module, the robot arm module, the power supply module, the sensor module, the heat sink and the audio module to control and communicate with the robot, wherein the sensor module comprises a depth camera, a laser sensor, a mobile phone recognition device, an infrared sensor, an ultrasonic sensor and a radiation dose chip, wherein the power module consists of a motor and an electronic speed controller and is thus responsible for the movement of the robot, wherein the robot arm module comprises a motor and a robot arm controller as well as an integrated NFC module on the robot arm, and wherein the power supply module comprises a battery, a power supply manager and a power supply display screen, while the audio module provides remote voice interaction.

The invention discloses a multi-section type linear array X-ray source static real-time CT imaging system and an imaging method, and the multi-section type linear array X-ray source static real-time CT imaging system is provided with a scanning device and a ray source control unit; the scanning device is provided with a multi-section X-ray source array and a detector, the transmitting end of the multi-section X-ray source array faces the detector, and the multi-section X-ray source array is connected with the ray source control unit. The multi-section X-ray source array has the advantages that the multi-section X-ray source array can freely adjust the length and the included angle of the whole section, and the multi-section X-ray source array is suitable for a large-size measured object; 2, the multi-section X-ray source array can use fewer X-ray sources to realize the same wide view field, the design is more free, and the expansion is easier; 3, the distribution of ray sources can be relatively dispersed, the crossing of ray paths is less, and the interference of scattered signals can be obviously reduced; and 4, the exposure strategy of the scanning device can be controlled through the radiation source control unit, and the radiation dose utilization rate is optimized.

The invention discloses a TSV-based multi-layer microsystem interconnection module total dose effect simulation modeling method, and relates to the technical field of three-dimensional integrated microsystems, and the method comprises the steps: obtaining geometric parameters and material parameters of a multi-layer three-dimensional microsystem interconnection module, building a finite element model of a microsystem module based on the geometric parameters and the material parameters, and carrying out the simulation modeling of the TSV-based multi-layer microsystem interconnection module total dose effect. Setting boundary conditions and port excitation; scattering parameters under different material conditions in the finite element model are extracted, frequency points are fixed, and a relational expression of the scattering parameters and material parameters is established; an RLC equivalent circuit model is constructed, and an equivalent circuit extraction method is obtained; according to an equivalent circuit extraction method, in combination with a relational expression of scattering parameters and material parameters, establishing a relationship between return loss parameters and equivalent circuit parameters; and establishing a relation model between the radiation dose and the resistance, inductance and capacitance in the equivalent circuit according to the relation between the return loss parameter and the equivalent circuit parameter. According to the invention, a scientific basis is provided for the reliability design of the three-dimensional microsystem in the radiation environment.

The invention provides an off-site full-range radiation risk evaluation method and system under a severe accident of a nuclear power plant, and the method comprises the steps: S1, building a radioactive accident risk evaluation basic model architecture, adapting to a model demand, and building a corresponding basic database; s2, constructing radioactive smoke plume characteristics after the accident; s3, calculating accident site space gridding and smoke plume transmission discretization; s4, sampling meteorological conditions, and simulating smoke plume transmission; s5, calculating the radiation dose in the early stage of the grid domain, and carrying out risk assessment; s6, performing risk assessment on the health effect in the early stage of the grid domain; s7, calculating the medium-and-long-term stage radiation dose in the grid domain, and performing dose risk assessment; and S8, performing health effect risk assessment and accident consequence assessment in the medium-and-long-term stage. According to the method, the whole transportation process of the radioactive smoke plume under a serious accident is simulated, loss effects such as dry and wet settlement and radioactive decay of the smoke plume are considered, and the activity of the radionuclide deposited on the ground and retained in the air in the off-site space range is determined.

The invention provides an industrial ray radiation dose visual simulation method and system based on FLUKA. The method comprises the following steps: creating and optimizing an X-ray machine model, setting radiation parameters, establishing an optimized radiation propagation model, carrying out simulation calculation, establishing the radiation intensity of a freely selected detection point or focus point according to a calculation result, and generating two-dimensional and three-dimensional dose and energy distribution diagrams. And establishing a dynamic radiation intensity calculation model and carrying out mistaken radiation accident simulation and evaluation. The system can accurately simulate and predict the dose of industrial ray radiation in real time, outputs a visual dose distribution diagram, provides a convenient and visual operation interface for workers, and is beneficial to improving the efficiency and safety of ray protection work. The method has wide application value in the aspects of industrial ray protection, mistaken irradiation accident early warning, ray device design optimization and the like.

The invention discloses a three-dimensional radiation field construction method and system, and the method comprises the steps: firstly obtaining an actual three-dimensional coordinate parameter set and an actual radiation dose rate parameter set of a to-be-measured scene, constructing a standard covariance matrix according to the parameters, selecting a to-be-predicted point, generating an actual covariance vector for the to-be-predicted point, and carrying out the calculation of the actual covariance vector. Generating predicted radiation dose rate parameters based on the standard covariance matrix and the actual covariance vector, and collecting the predicted radiation dose rate parameters of the plurality of points to be predicted into a predicted radiation dose rate parameter set, and finally, generating a three-dimensional radiation field according to the actual three-dimensional coordinate parameter set, the actual radiation dose rate parameter set and the predicted radiation dose rate parameter set. According to the method, the correlation between the trajectory points is represented through the covariance, and the conversion relation between the to-be-predicted point and each trajectory point is established through the conversion relation between the actual covariance vector and the standard covariance matrix, so that the radiation dose rate of the predicted point is calculated, the radiation dose rate of more point positions is obtained, and the precision of the three-dimensional radiation field is improved.

Organometallic precursors are described for the formation of high resolution lithography patterning coatings based on metal oxide hydroxide chemistry. The precursor compositions generally comprise ligands readily hydrolysable by water vapor or other OH source composition under modest conditions. The organometallic precursors generally comprise a radiation sensitive organo ligand to tin that can result in a coating that can be effective for high resolution patterning at relatively low radiation doses and is particularly useful for EUV patterning. The precursors compositions are readily processable under commercially suitable conditions. Solution phase processing with in situ hydrolysis or vapor based deposition can be used to form the coatings.

The invention provides a signal processing method for radioactivity detection equipment and the radioactivity detection equipment, and the signal processing method for the radioactivity detection equipment comprises the steps: analyzing a collected nuclear pulse signal, and obtaining pulse amplitude information; performing spectrum stabilization according to the pulse amplitude information to obtain a spectrum-stabilized energy spectrum; and determining a nuclide identification result and a dose rate calculation result based on the spectrum-stabilized energy spectrum. According to the technical scheme, on one hand, the current environment dose rate level can be determined, it is ensured that the radiation dose received by workers is within the safety limit value, and therefore the radiation risk can be reduced, and the health and safety of the workers are guaranteed; and on the other hand, specific radionuclides can be identified, so that the pollution source can be determined.

The invention discloses a temperature control method for low-temperature high-NOx-concentration flue gas denitration in the nuclear industry, and relates to the technical field of flue gas denitration control. According to the method, flue gas temperature time sequence distribution, NOx concentration gradient and environment radiation intensity data are integrated through a space-time alignment algorithm, a synchronous data matrix representing a system coupling state is generated, then a temperature and efficiency response curved surface is established, a high-efficiency temperature area and an inactivation risk area are dynamically divided through fuzzy logic control, and an optimal temperature regulation and control threshold value is recognized. The drift effect of quantitative radiation on the surface temperature of the catalyst is analyzed through regression, a quantitative relation model of radiation dose and temperature zone deviation is established, and real-time correction of anti-radiation compensation parameters is achieved. And finally, optimizing the multi-objective cost function by adopting a non-dominated sorting genetic algorithm, and obtaining dynamic balance between the maximum NOx conversion rate and the minimum temperature fluctuation. And multi-parameter coupling control of a temperature field and a radiation field is realized, and the denitration efficiency stability under a low-temperature condition is remarkably improved.

The invention relates to the technical field of medical image processing, in particular to a nasopharyngeal carcinoma pseudo CT generation method based on multi-modal deformation registration and a Transform network, and the method comprises the steps: firstly collecting CT and MRI images of a nasopharyngeal carcinoma patient confirmed by pathology, and carrying out the preprocessing of the CT and MRI images; secondly, establishing a deformation registration network based on a CycleFCNs model, inputting the CT image as a fixed image and the MRI image as a floating image, outputting a space deformation transformation field, and performing deformation transformation on the MRI image; then, a decoder is added on the basis of the original Transform model, a loss function is set, and the weight is adjusted; the image subjected to deformation registration is used as training data to be input into the improved Transform model for training optimization; and finally, generating a pseudo-CT image from the to-be-processed MRI image by using the trained model, and performing imagery evaluation by using various evaluation indexes. The accuracy and quality of pseudo CT generation are improved, the radiation dose of a patient is reduced, and the method has important clinical application value in the field of nasopharyngeal carcinoma radiotherapy.

The invention provides a reactor pressure vessel flange sealing surface defect measuring method and a reactor pressure vessel flange sealing surface defect repairing method. The measuring method comprises the following steps: S1, measuring and calculating the minimum diameter and the maximum diameter of an annular band formed in a sealing ring indentation range; and S2, by taking the center of the container flange as a circle center, inspecting the defect, falling into the range of the annular belt between the minimum diameter and the maximum diameter, on the container flange, and measuring and recording the size and the orientation of the defect. According to the method, corresponding recommended repair methods are provided according to repair criteria for defects of different scales, the method can be used for guiding implementation of nuclear power plant RPV sealing surface maintenance, the repair workload is effectively reduced, the radiation dose of personnel is reduced, the operation and maintenance efficiency is improved, safe and stable operation of a nuclear power unit is ensured, and the economic benefit of power station operation is improved.

A computer tomography scanner (102) includes a radiation source (112) configured to emit x-ray radiation, a detector array (116) configured to detect x-ray radiation and generate a signal indicative thereof, and a reconstructor (118) configured to reconstruct the signal and generate sequential spares time line perfusion volumetric image data. The computer tomography scanner further includes a processor (132) configured to process the sequential spares time line perfusion volumetric image data using a trained neural network of a perfusion data enhancing module (136) to produce sequential dense time line perfusion volumetric image data.

The invention relates to the technical field of radiation dose monitoring, in particular to a radiation dose monitoring method, device and system, and the method comprises the steps: obtaining the radiation dose data of a flaw detection room, and the temperature and humidity data in the environment; obtaining an influence coefficient of a linear fluctuation degree of radiation dose data caused by environment temperature change and humidity change, and further obtaining an influence coefficient of radiation dose monitoring caused by environment temperature and humidity change; the radiation dose irregular fluctuation change degree caused by equipment operation is calculated, the influence coefficient of the start-stop frequency and the time interval of the equipment is obtained, and the comprehensive influence significance value of the radiation dose monitoring by the environment change and the equipment operation state is obtained by combining the dispersion degree of all radiation dose data. And adjusting the step length factor in the radiation dose monitoring data filtering process to obtain a radiation dose monitoring result. According to the invention, the radiation dose data monitoring precision can be improved.

The invention relates to a nuclear facility radiation field model construction method and a dose evaluation system, and the system is configured to establish a three-dimensional space coordinate system, construct a three-dimensional radiation field model based on radiation field data and radiation source data, and correct the radiation field model at the current moment according to the radiation source data, introducing an attenuation coefficient of the three-dimensional nuclear facility on the original three-dimensional scene model to correct the three-dimensional scene model; correcting the radiation field model based on the corrected three-dimensional scene model; calling the three-dimensional scene model and the radiation field model according to an operation path selected by a user; and simulating the space range of each organ of the human body sweeping along with the movement of the human body in the working path in the three-dimensional scene model, obtaining the time of each organ staying on the path of the unit space, and calculating the real-time dose received by the human organ according to the radiation dose rate in the unit space. According to the invention, the change of the radiation field caused by the disassembly and assembly of the nuclear facility can be corrected, and the optimization of radiation protection is realized.

The invention discloses a nuclear power plant secondary side cleanliness evaluation and radiation shielding method. The method comprises the following steps that S1, whole secondary circuit system equipment of a steam generator is washed; s2, full-coverage cleanliness inspection is carried out in the range from a filter screen of the electric main water feeding pump system to the secondary side of the steam generator, and meanwhile, if foreign matter is found, a cleaning tool is used for picking up the foreign matter; s3, evaluating the cleanliness condition, and if the cleanliness is qualified, ending; if the cleanliness is not qualified, returning to the step S1; s4, if the foreign matter falls off after the steam generator runs, stopping the equipment, and filling the secondary side of the steam generator with water to a preset position for reducing the radiation dose; and S5, picking up foreign matters by using a cleaning tool. Full-coverage cleanliness inspection is carried out in the range from the filter screen of the electric main feed pump system to the secondary side of the steam generator, effective verification of the secondary loop foreign matter flushing effect and radiation shielding when necessary are achieved, and foreign matter remaining on the secondary side of the steam generator is avoided.