The process pipelines of nuclear power plants shall undergo non-destructive testing before being put into operation.

However, there are many items in the nuclear power plant and the pipeline headroom is small, which often results in unreachable weld inspection due to the interference of surrounding items, causing serious safety and quality hazards.

In order to ensure sufficient space for weld inspection and repair, the installed items are often dismantled on site, and some even need to gouge away the concrete wall. Therefore, it is necessary to fully consider the space required for non-destructive testing at the design source.

When using non-destructive testing technology to carry out inspections in the field of nuclear power, it is based on the premise of not damaging the performance of the tested object, and based on the theories of physics, chemistry and materials, the effective inspection of equipment parts is mainly performed on the equipment. External inspection, inspection of the surface and appearance of the equipment, inspection of the volume of the equipment, and so on.

For the detection work in other areas, remote equipment and remote control equipment can be used for detection.

For example: when detecting in an environment with affine properties, it can be monitored by remote detection technology.

The appearance inspection can be carried out by remote inspection.

Check the parts of the equipment, check the safety of the small parts that make up the equipment, check whether the parts and equipment are loose and damaged, check whether the components are loose and corroded, and ensure the integrity of the equipment components.

For surface inspection work, magnetic powder can be used to combine with liquid penetration to ensure its permeability and later surface inspection work.

When monitoring, the environment that is easily accessible to personnel can be detected by remote detection methods and magnetic particle penetration methods.

For areas that are not easily accessible to workers, the detection of volumes can be done by ultrasonic methods, which can achieve intelligent detection targets in the field of nuclear power.

The eddy current detection method is mainly used to detect the pipe that produces steam. It can detect the thin thickness of the corroded pipe wall, and detect the defects caused by operating errors in the actual installation project. For example, to detect dents.

①Non-destructive testing personnel management

Strictly manage the qualification training and examination work of non-destructive testing personnel. The training "Regulations on the Qualification Management of Non-destructive Testing Personnel for Civil Nuclear Safety Equipment" comprehensively learns the management requirements and assessment technical requirements, is familiar with the qualification coverage and scope of application, and conducts on-site operations as required. Standardize operations within the certification qualifications.

Dynamic management qualifications, continuous maintenance of qualifications and qualifications, skilled personnel, can solve specific flaw detection problems on the spot, and prevent fraudulent use of qualifications or flaw detection beyond the scope of qualifications, and unlicensed employment.

It is necessary to strictly abide by the provisions of the Nuclear Safety Law, and it is strictly forbidden to borrow and operate radiation sources in different enterprises, and to mix radiation sources.

②The inspection culture of non-destructive testing

Strictly implement the "zero tolerance for illegal operations", "zero tolerance for fraudulent practices", and "zero tolerance for concealment of false reports", to achieve hierarchical organization and each responsibility;

Full participation, highlight the key points of welding management, analyze welding cases, learn lessons and feedback from experience, establish rules and regulations, continue to improve and improve, one-time successful welding, guarantee quality, and prevent rework.

The quality assurance and inspection responsibility culture needs to pay attention to the improvement of the non-destructive testing system and the familiarity with technical standards, especially the compliance with the inspection and acceptance standards and the mandatory provisions of engineering construction, and the unified benchmarking between the welding standards and the non-destructive testing standards to eliminate The habitual bad practices of the inspectors are strictly in accordance with the requirements of the non-destructive testing process qualification for process development and on-site testing, and the sampling inspection ratio is fully covered, "RT and 100% RT welding according to a certain proportion"

Both need a good cultural atmosphere with equal attention.

③Non-destructive data management

Regarding the management of non-destructive testing data, what needs to be checked is the joint control of welding control sheets, welding commissioned inspection control sheets, and repair notices and non-destructive methods.

For the review of NCR and non-destructive testing reports, the manufacturer’s RT film and report and the RT report of the pre-service inspection unit on the same part and the same weld should be fully integrated when reviewing the non-destructive report to facilitate the discovery of the specific shape and defect distribution of the defect. Trend, as a reference for follow-up production.

3.1Testing standards and personnel training and evaluation

In order to realize the application value of non-destructive testing technology, ensure the stability of the equipment, and ensure the safety of the actual operation of the equipment, it must meet certain testing standards when testing and installing the equipment.

For example, when using non-destructive testing technology for testing operations, you can learn the testing standards and requirements of Western architecture.

Such as: the American ASME boiler and pressure vessel code, and the nuclear island mechanical equipment design and construction rules issued by France to ensure the standardization and safety of the non-destructive testing technology in the actual application process.

Secondly, in order to achieve the application effect of non-destructive testing technology, the testing staff must be judged and trained to ensure the correctness of the application of non-destructive testing technology.

For non-destructive testing staff, conduct skills and professional knowledge training to ensure that they have the theoretical knowledge of testing, ensure that they have good practical operational capabilities, and evaluate the work of non-destructive testing staff based on the non-destructive testing technology of civil nuclear safety equipment Assessment-norms and requirements, to inspect and evaluate its testing work, find its shortcomings and shortcomings, and conduct targeted education and training for it, so that senior employees with rich testing experience can guide and educate. In the process of work, A reward and punishment system can be established to reward staff with better performance in testing to stimulate their enthusiasm for their work, increase their enthusiasm for testing, warn staff with poor performance, and increase the standardization of their work behavior. Set an example and benchmark internally to play a demonstrative role, ensure the orderly development of testing work, and promote the development of the nuclear power industry.

3.2Non-destructive testing laboratory work joint inspection

Pay attention to the inspection of the correct operation of the inspection system, the consistency inspection of the process and the results, specify the corresponding non-destructive inspection methods and content, and do visual inspection, weld size inspection, penetration inspection, vacuum leak inspection, ultrasonic The correct application of inspection, radiographic inspection, phased array inspection, eddy current inspection and other methods, pay special attention to the full coverage of the welder's random inspection ratio, especially the first weld and random inspection of each welder, double inspection if necessary And full inspection to verify the welding quality.

Carry out quarterly joint inspections of welding and non-destructive testing quality, joint inspections of engineering entities and engineering documents, look back on quality problems, sample inspections and check the main control dimensions of welds according to the requirements of the mandatory provisions of the standard, especially welds Measure and inspect the compliance of the width, length, and size of the welding foot, check the surface condition of the weld, check and remove defects such as pores, slag inclusions, lack of fusion, incomplete penetration, undercuts, etc.;

Check the welding control list, including the status of welder's steel stamp number, weld identification, etc., review the arrangement of welding records, review time, space and process logic, and check the connection between welding and non-destructive testing records and reports to ensure The quality is under control.

In summary, non-destructive testing technology plays an irreplaceable role in the field of nuclear power. In order to give full play to the high-quality effects of non-destructive testing technology, the staff must ensure the scientific nature of non-destructive testing technology testing methods in actual testing work, and use remote monitoring Methods and close contact methods, using radiographic and ultrasonic volume methods and magnetic particle penetration surface detection methods to monitor, to ensure the integrity and diversity of the main work content of non-destructive testing technology, and to classify and test different testing content. Testing standards and personnel training and evaluation ensure the enthusiasm of testing staff, establish a reward mechanism with clear rewards and punishments, increase staff enthusiasm, and ensure the good development of monitoring work.