Download document

Federal Supervision of Russia for Nuclear and Radiation Safety
(Gosatomnadzor of Russia)

SAFETY MANUALS

UNIFIED CONTROL METHODS
BASIC MATERIALS (SEMI-FINISHED PRODUCTS),
WELDED JOINTS AND SURFACES
NPP EQUIPMENT AND PIPELINES

The technique applies to surfacing and welded joints with a radiation thickness of up to 400 mm, controlled using penetrating radiation - X-ray, gamma and bremsstrahlung radiation from electron accelerators and radiographic film.

1. General provisions. 2 2. Certification of controllers. four 3. Materials and accessories for radiographic control. 4 4. Preparation for control.. 4 5. Control schemes. 7 6. Parameters and modes of control. 12 7. Checking and photo processing of radiographic film. fifteen 8. Deciphering pictures. 16 9. Documentation requirements. 17 10. Storage of radiographic film. Storage and destruction of radiographic images and fixing solution. eighteen 11. Metrological support. 18 12. Radiographic control under background radiation conditions. 19 13. Security requirements. 21 Annex 1 Sample technological map radiographic control. 21 Annex 2. Method for assessing the concavity and convexity of the root of the weld when they are not available for external examination. 22 Appendix 3. Selection of the distance from the radiation source to the controlled welded joint and the length or number of controlled sections. 23 Appendix 4. Determination of the exposure time during radiographic control and gamma-graphic control using sources of iridium-192 and cobalt-60. 25 Annex 5. The composition of the reducing solution for the "roentgen-2" developer. 26 Appendix 6. Defects in photo processing of radiographic images. 27 Appendix 7. Radiographic Film Inspection Log. 27 Appendix 8. Journal of the preparation and recovery of photo solutions. 27 Appendix 9. Interpretation of images with dark stripes, which by their nature cannot be interpreted as images of lack of penetration. 27 Appendix 10. Conclusion on the results of radiographic testing. 28 Appendix 11. List of standards referenced in this methodology. 28

1. GENERAL PROVISIONS

1.1. Radiographic control is carried out in order to detect in surfacing and welded joints (weld and near-weld zone):

1.3. Radiographic control does not provide detection of:

Any defects with dimensions in the direction of transmission less than twice the sensitivity of the control;

Any defects, if their images in the picture coincide with images of other parts, sharp corners, differences in the thickness of the translucent metal;

Lack of penetration and cracks, if their opening is less than the values ​​given in Table. 1, and (or) the plane of their disclosure does not coincide with the direction of transmission.

Table 1

Note. In accordance with GOST 24034-80, hereinafter, the radiation thickness should be understood as the total length of the sections of the axis of the working beam of directed primary radiation in the material of the controlled object.

1.4. The scope of control and standards for assessing the quality of surfacing and welded joints according to the results of the control, they are established by the document “Equipment and pipelines of nuclear power plants. Welded joints and overlays. Control Rules". PNAE G-7-010-89 (hereinafter referred to as PNAE G-7-010-89).

1.5. When designing units and structures of nuclear power plants and assigning control, it is necessary to take into account that:

Control can be carried out only if there is a two-sided access to the controlled surfacing or welded joint, which makes it possible to install a cassette with a film and a radiation source in accordance with the requirements of this method;

Be subject to control with an internal diameter of fittings and pipes of at least 15 mm;

Surfacings and welded joints with a ratio of the radiation thickness of the deposited metal to the total radiation thickness in the direction of transillumination of at least 0.2 may be subjected to control.

1.6. Prior to the inspection, all surfacings and welded joints subject to control (or groups of identical surfacings and welded joints) should be drawn up technological control charts, including:

Basic information about the controlled surfacing or welded joint (product number or code, name and number of the surfacing or welded joint, category of surfacing or welded joint and control rules by which the acceptance of the surfacing or welded joint should be carried out, the thickness by which the quality of the surfacing or welded joint in accordance with PNAE G-7-010-89, etc.);

Transmission scheme indicating the location of the sensitivity standard;

Type and number of the sensitivity standard;

Required sensitivity;

Radiation source (for X-ray machines, the voltage and the maximum size of the focal spot of the X-ray tube are indicated; for radionuclide sources, the type of source; for the accelerator, the energy of accelerated electrons);

The distance from the radiation source to the controlled weld or surfacing and the distance from the weld or surfacing to the radiographic film;

Type and dimensions of radiographic film;

The thickness of the intensifying screens;

Number and size of controlled areas;

The beginning and direction of the marking of the plots.

Other additional information may also be included in the map, for example, the radiation thickness of the controlled surfacing or welded joint, marking of areas (images), etc. The card must be signed by its developer and the head of the control unit.

When enlargement (including at manufacturing plants) and installation, it is allowed to use standard technological maps developed by the leading materials science organization.

An example of a radiographic checklist is given in the recommended Appendix 1.

2. CERTIFICATION OF INSPECTORS

2.1. To carry out radiographic control of welded joints and surfacing of NPP equipment and pipelines, inspectors certified in accordance with the requirements of the document ПНАЭ Г-7-010-89 are allowed.

3. MATERIALS AND ACCESSORIES FOR RADIOGRAPHIC TESTING

3.1. X-ray machines, radionuclide sources for gamma-ray flaw detection (ytterbium-169, thulium-170, selenium-75, iridium-192, cobalt-60) and sources of hard bremsstrahlung (betatrons, microtrons and linear accelerators with radiation energy not exceeding 35 MeV).

3.2. During radiographic control, radiographic films RT-1, RT-4M, RT-4Sh, RT-5 with an unexpired shelf life should be used.

The use of other films and films with an expired shelf life is allowed only in agreement with the leading industry materials science organization.

3.3. Film loading cassettes must be light-tight and ensure that the film adheres tightly to the intensifying screens.

If the control conditions do not require film bending, it is recommended to use rigid cassettes.

3.4. As intensifying screens, only metal intensifying screens should be used - lead and lead-tin foils according to GOST 18394-73, GOST 9559-75, GOST 15843-79.

For radiation energy of 1 MeV and above, it is allowed to use copper-brass and steel intensifying screens.

3.5. The screens must have a clean, smooth surface free of wrinkles, scratches, wrinkles, tears, holes, foreign inclusions and other defects, the images of which in the pictures may make it difficult to decipher them.

3.6. To protect the film from scattered radiation (shielding of the film cassette from the side opposite to the radiation source), it is recommended to use lead protective screens.

3.7. Numbers and letters of the Russian or Latin alphabets, as well as additional signs in the form of arrows, dashes, etc., should be used as markings.

3.8. Markings and limit marks should be made of lead or other materials that ensure their clear image in the photographs.

The dimensions of the markings must comply with the requirements of GOST 15843-79.

3.9. To assess the sensitivity of radiographic control, wire or groove sensitivity standards should be used in accordance with GOST 7512-82.

3.10. To assess the concavity and convexity of the weld root, which is inaccessible for external inspection and measurement, steel samples should be used - concavity and convexity simulators.

The design of simulative specimens and the procedure for their use are given in mandatory Appendix 2.

4. PREPARATION FOR CONTROL

4.1. Welded joints subject to control must be cleaned of scale, slag, metal splashes and other contaminants. At the same time, all external defects detected during external examination, as well as irregularities, the images of which in the image may interfere with the identification and interpretation of images of internal discontinuities and inclusions of the welded joint, must also be eliminated.

4.2. After stripping the welded joint and eliminating external defects, the welded joint is marked into sections and the sections are numbered (marked) in a manner that does not impair the quality and operational reliability of the welded joints.

4.3. The marking and marking of the welded joint must be retained until its final acceptance.

4.4. The system of marking and marking sections (the beginning and direction of numbering) should provide the possibility of resuming the marking and numbering.

4.5. Before testing, markings, sensitivity standards and limit marks should be installed on the controlled sections of the welded joint at the boundaries of the sections, as well as at the boundaries of the deposited weld metal when inspecting welds without a bulge or with a removed bulge (for example, when machining). The scheme of installation of marking marks of sensitivity standards and limit marks is shown in fig. one.

Rice. one. Scheme of installation of marking marks of sensitivity standards and limit marks:

1 - limit marks; 2 - markings; 3 - sensitivity standard (marking of the sensitivity standard according to GOST 7512-82); 4 - arrows limiting the width of the seam with the bulge removed; 5 - weld; 6 - welded seam with the bulge removed; 7 - heat-affected zone

4.6. Markings should be installed on the controlled product (installation on a cassette with a film is allowed) so that their images in the pictures do not overlap the image of the seam and the controlled areas of the heat-affected zone, determined in accordance with the requirements of clause 6.15.

4.7. Marking on the images should repeat the marking of controlled areas.

If it is impossible to install markings on the controlled area of ​​the welded joint, it is allowed to mark the images in any way that ensures the safety of the marking during storage of the images (for example, with a pencil, a light or perforation marker, etc.).

In this case, an entry “Marking with a pencil (or in another way) is allowed” should be made in the technological map or log of the results of control, with the signature of the head of the unit performing radiographic control.

4.8. Marking should provide the possibility of identifying the structure and section of the welded joint to which the radiographic image belongs, as well as the possibility of finding an entry in the log of inspection results related to the image, or a snapshot from an entry in the log.

When monitoring the largest objects (products), it is recommended to keep a separate log for each object (product). In this case, the number (or code) of the controlled object (product) can be assigned to the journal.

4.10. When re-inspecting a welded joint after repair, the letter P (or R) should be included in the marking, after the second repair - 2P (or 2R).

It is also allowed to include in the marking the number or conditional code of the flaw inspector who performed the inspection.

4.11. Sensitivity standards should be installed on the controlled area of ​​the welded joint on the side of the radiation source.

If it is impossible to set the sensitivity standard on the side of the radiation source when inspecting welded joints of cylindrical, spherical and other hollow products through two walls with deciphering the image of only the area of ​​the welded joint adjacent to the film and with panoramic transillumination, it is allowed to set sensitivity standards from the side of the film cassette.

4.12. Wire sensitivity standards should be installed directly on the seam with the direction of the wires across the seam.

4.13. Groove sensitivity standards should be installed with the direction of the standard along the seam at a distance from it:

for butt welded joints:

With a thickness of welded edges up to 5 mm - not less than 5 mm;

With the thickness of the welded edges from 5 to 20 mm - not less than the thickness of the welded edges;

With a thickness of welded edges over 20 mm - at least 20 mm;

For corner and tee welded joints - at least 5 mm.

4.14. If it is impossible to set the sensitivity standard on the tested welded joint or if it is impossible to obtain its image in the image (for example, when inspecting fillet and tee welds, when inspecting pipe welds into tube sheets, etc.), it is allowed:

Install groove sensitivity standards directly on the seam with the direction of the standard along the seam, if the length of the seam section controlled in one exposure exceeds the length of the standard by at least 5 times or the image of the standard is outside the borders of the image of the seam section being decoded;

Determine the sensitivity using a standard on specimens-simulators of a welded joint with a radiation thickness equal to the radiation thickness of the controlled welded joint.

The possibility of carrying out control without setting a standard (with a sensitivity test on a simulator sample) should be provided in the control flow sheet.

4.15. If during panoramic transillumination of circumferential welded joints no more than four films are installed on the seam, the number of sensitivity standards to be installed must correspond to the number of films. If more than four films are installed, it is allowed to install one sensitivity standard for each quarter of the circumference of the seam.

4.16. When testing welded joints in pipelines with a diameter of up to 100 mm, it is allowed not to set limit marks at the boundaries of sections controlled in one exposure, and also to install groove sensitivity standards along the pipe axis.

5. CONTROL SCHEMES

5.1. Rectilinear and close to rectilinear welded joints (welded joints of flat elements, longitudinal seams of cylindrical products, welded joints of cylindrical and spherical products with a diameter of more than 2 m, etc.) should be controlled according to the schemes shown in fig. 2.

Rice. 2. Inspection schemes for rectilinear and close to rectilinear welded joints:

1 - radiation source; 2 - controlled area; 3 - cassette; 4 - lining plate; h - radiation thickness

5.2. Butt girth welded joints of cylindrical and spherical hollow products (pipelines, tanks, etc.) should be controlled according to the schemes shown in fig. 3.

Rice. 3. Control schemes for butt girth welded joints of cylindrical and spherical hollow products:

1 - radiation source; 2 - controlled area; 3 - cassette; 4 - lining plate; f - distance from the radiation source to the controlled connection

5.3. When testing welded joints of cylindrical and spherical hollow products, as a rule, it is necessary to use schemes of transillumination through one wall of the product (see Fig. 3, a, b, f - h). In this case, it is recommended to use transmission schemes with the location of the radiation source inside the controlled product (see Fig. 3, f - h).

5.4. The scheme shown in fig. 3, f (panoramic transillumination), it is recommended for testing products with a diameter of up to 2 m, regardless of the volume of control and for testing products with a diameter of more than 2 m at 100% control.

5.5. The scheme shown in fig. 3, g, it is recommended for 100% and selective control of products with a diameter of up to 2 m, if the use of the scheme shown in fig. 3f, impossible; the circuit shown in fig. 3, h, - during selective control of products with a diameter of more than 2 m.

5.6. When checking through two walls, the scheme of Fig. 3, c is recommended for translucent products with a diameter of not more than 100 mm, diagram fig. 3, d, e - for translucent products with a diameter of more than 50 mm.

5.7. During the control of butt welded joints according to the schemes of fig. 3, a, b, f, g, h, the angle between the direction of transillumination and the plane of the tested welded joint must be minimal and not exceed 15°.

5.8. During the control of butt welded joints according to the schemes of fig. 3, c, d, e, the direction of transillumination should be chosen so that the projections of the opposite sections of the weld in the image do not overlap. If this condition is not feasible, the control is carried out in accordance with the requirements of clause 5.7.

5.9. Welded butt welded joints with an inner diameter of 30 mm or more and welded butt welded joints with an inner diameter of 15 to 30 mm, controlled in stationary conditions, should be controlled according to the schemes shown in Fig. 4, a - d.

5.10. Welded joints for welding fittings with an inner diameter of 15 to 30 mm, controlled under installation conditions, should be controlled according to the scheme shown in fig. 4, d.

Rice. four. Schemes of control of welded joints for welding fittings:

a - d - for stationary conditions; d - for installation conditions; 1 - radiation source; 2 - controlled area; 3 - cassette; 4 - lining bar.

5.11. Welded joints for welding pipes with an inner diameter of 15 mm or more into tube sheets should be controlled according to the schemes shown in Fig. 5, a - e.

5.12. To reduce the difference in optical densities of individual sections of the image when inspecting welded joints with large differences in radiation thickness, and also in cases where the controlled welded joint does not protect the film from direct radiation (when inspecting end welded joints, when inspecting welding edges for welding, etc.) etc.), control should be carried out using attachments-compensators, as shown in Fig. 5.

It is allowed to use compensators from any material that provides the required radiation attenuation.

5.13. Along with the schemes and directions of transillumination shown in Figs. 2 - 5, other schemes and directions of transillumination can be used, which should be provided in the technological control charts.

5.14. When choosing a scheme and direction of transillumination, along with the requirements and recommendations listed above, the following must be taken into account:

The distance from the radiographic film to the surface of the inspected welded joint facing it should be minimal and in any case not exceed 150 mm;

The angle between the direction of radiation and the normal to the radiographic film within the area of ​​the welded joint controlled during one exposure should not exceed 45°.

Rice. 5. Schemes of control of welded joints for welding pipes into tube sheets:

1 - radiation source; 2 - controlled area; 3 - cassette; 4 - attachment-compensator; other designations see fig. 2

6. PARAMETERS AND CONTROL MODES

6.1. The source of radiation and the type of radiographic film should be selected according to Table. 2.

table 2

Radiation thickness, mm	Radiation source	radiographic film
Up to 5 inclusive	X-ray machine, ytterbium-169, thulium-170	RT-4M, RT-4Sh, RT-5
Over 5 to 20 inclusive	X-ray machine, thulium-170, selenium-75, iridium-192	RT-4M, RT-4Sh, RT-5
Over 20 to 50 inclusive	X-ray machine
	Iridium-192	RT-4M, RT-4Sh, RT-5
Over 50 to 100 inclusive	X-ray machine, iridium-192
	Electron accelerator, cobalt-60	RT-4M, RT-4Sh, RT-5
Over 100 to 200 inclusive	Electron accelerator	RT-4M, RT-4Sh, RT-5
	Cobalt-60
	Electron accelerator

Notes:

1. In each range of radiation thicknesses, radiation sources are listed in order of preference for their use. For example, in the range of 5 - 20 mm, it is preferable to use an X-ray machine as a radiation source, if it is impossible to use an X-ray machine - thulium-170, etc.

2. It is allowed to use radiographic films RT-4M, RT-4Sh, RT-5 instead of film RT-1.

3. The use of other radiation sources and radiographic films, as well as those given in Table. 2 sources and films in other ranges of radiation thicknesses are allowed upon agreement with the industry materials science organization.

6.2. The voltage on the X-ray tube and the energy of accelerated electrons when using accelerators should be selected in accordance with the requirements of GOST 20426-82.

6.3. The thickness of the intensifying screens should be selected according to Table. 3.

Table 3

Notes:

1. When using copper, brass and steel reinforcing screens given in table. 3 thickness can be increased up to two times.

2. It is allowed to use reinforcing screens with other thicknesses if these screens are supplied in the same package with the film.

3. When using screens with different thicknesses, the thicker screen should be used on the side opposite the source. In this case, its thickness may exceed that given in Table. 3.

Table 4

6.5. The distance from the radiation source to the surface of the inspected welded joint facing the source (when girth welded joints are translucent through two walls, to the surface of the ring joint adjacent to the source) and the size or number of areas controlled in one exposure: for all transillumination schemes (except for the scheme shown in Fig. 3, f) should be chosen such that the following requirements are met during transillumination:

The geometrical blurring of images of defects in the images when the film is located close to the inspected welded joint should not exceed half the required sensitivity of the control with a sensitivity of up to 2 mm and 1 mm - with a sensitivity of more than 2 mm;

The relative increase in the size of images of defects located on the side of the radiation source (in relation to defects located on the side of the film) should not exceed 1.25;

The angle between the direction of radiation and the normal to the film within the area controlled for one exposure should not exceed 45°;

The decrease in the optical density of the image of the welded joint in the image on any part of this image in relation to the optical density of the image of the sensitivity standard (or the section of the welded joint on which the wire sensitivity standard is installed) should not exceed 1.0.

6.7. The exposure should ensure that the optical density of the image of the seam, the standard of sensitivity and the controlled near-seam zone in the image is not less than 1.5 and not more than 3.5.

When inspecting welded joints with a variable cross section, it is allowed to increase the optical density, images of sections of the welded joint with the smallest thickness up to 4.0.

6.8. During X-ray and gamma-graphic control using sources of iridium-192 and cobalt-60, it is recommended to determine the exposure time according to the method given in the recommended Appendix 4, when using other sources - empirically.

6.9. When inspecting circumferential welded joints according to the scheme shown in fig. 3, e (panoramic transillumination), the ratio of the inner diameter d to outside diameter D controlled welded joint should not be less than 0.8, and the maximum size Ф of the focal spot of the radiation source should not be more than kd/(D - d) mm, where K- control sensitivity, mm.

6.10. In cases where the relative increase in the size of images of defects located on the side of the radiation source (in relation to defects located on the side of the film) can be neglected, the ratio given in clause 6.9 between the inner and outer diameters of the tested welded joint may not be observed.

6.11. The length of the images should ensure overlapping of images of adjacent sections of welded joints by at least 0.2 of the length of the section with its length up to 100 mm and at least 20 mm with its length over 100 mm.

6.12. The width of the images should provide images of the weld, sensitivity standards, markings and the heat-affected zone with a width of:

For corner and tee welded joints, as well as for butt welded joints with a thickness of welded edges up to 5 mm - at least 5 mm;

For butt welded joints with a thickness of the welded edges from 5 to 20 mm - not less than the thickness of the welded edges;

For butt welded joints with a thickness of welded edges over 20 mm - at least 20 mm;

For butt welded joints made by electroslag welding - at least 50 mm (regardless of the thickness of the welded edges).

6.13. When choosing the size of images and sections of welded joints controlled in one exposure, it is also recommended to be guided by the standard sizes of radiographic films in accordance with GOST 15843-79.

6.14. It is recommended to choose the thickness of the limit marks and the dimensions of the markings according to the table. 5 and 6.

6.15. Charging of cassettes should be carried out according to one of the schemes given in Table. 7.

Table 5

6.16. To reduce the impact of scattered radiation on the radiographic film, it is recommended to take measures to reduce the size of the irradiated field through the use of lead collimators and tubes installed on the radiation source and limiting the angular dimensions of the radiation beam, as well as lead diaphragms installed on the controlled welded joint and limiting the size of the irradiated field the dimensions of the welded joint area controlled in one exposure.

Table 6

Table 7

Notes:

1. When loading a cassette with two films, depending on the task, films of the same or different types can be used.

2. When charging two films with intensifying screens, the thickness of the middle screen is selected depending on the task.

7. CHECKING AND PHOTOPROCESSING OF RADIOGRAPHIC FILM

7.1. Before using each new batch of radiographic film, its suitability for radiographic inspection should be determined. To do this, exposed and unexposed films from this batch are subjected to photo processing.

7.2. For exposure of the film, it is allowed to use any of the radiation sources provided for in clause 3.1. The exposure time is chosen such that the optical density of the exposed film is not less than 1.5 and not more than 3.5.

7.3. A batch is considered suitable for radiographic control if the exposed and unexposed films from this batch after photo processing have a uniform optical density without any bands, spots and drops (irregularities) of optical density visible during visual inspection and the optical density of the unexposed film does not exceed limit value provided by the film manufacturer.

7.4. If the exposed and (or) unexposed films do not meet the requirements of clause 7.3, films from each box of the batch are subjected to a similar check. Boxes, the films from which do not meet the requirements of clause 7.3, are rejected.

7.5. Preparation (loading and unloading of cassettes) and photo processing of radiographic film should be carried out under non-active illumination. In the source of non-actinic lighting - a photo torch, an electric lamp with a power of not more than 25 W should be used, the distance from the photo torch to the workplace where the film is manipulated should not be less than 0.5 m.

7.6. The non-actinity of illumination is checked by exposing a sheet of film at a distance of 0.5 m from the photolamp. Half of this sheet is protected from exposure with black paper. Illumination is considered non-active if after photo processing there is no noticeable boundary between the exposed and unexposed parts of the film.

7.7. Photo processing of radiographic images should be carried out in specialized photo processing machines or in tanks (tank photo processing) in accordance with the recommendations of the film manufacturer.

7.8. Tank photo processing should include developing, intermediate washing, fixing, pre-washing, final washing.

Notes:

1. The photo processing process may include film processing after final washing in a 0.03 - 0.05% aqueous solution of wetting agent OP-7 or OP-10 according to GOST 8433-81 or in an aqueous solution of wetting agent SV-1017 according to TU 6 -14-934-73 at the rate of 0.3 - 1.0 g / l of water. Duration of treatment in solutions 0.5 - 1.0 min.

2. It is allowed, in agreement with the leading material science organization, to include additional operations in the photo processing process, for example, enhancing the optical density of images by dispersing silver, etc.

7.9. Images for tank photo processing should be placed vertically with a distance of at least 20 mm between them. The upper edges of the images should be at least 30 mm below the level of the solutions. It must be ensured that the temperature of the solutions is maintained within the limits recommended by the film manufacturer, and that the developer is stirred during photo processing.

Note. Instead of mixing the developer, it is allowed to carry out reciprocating movement of images with a frequency of 5 - 10 times per 1 minute by a value of 10 - 20 mm.

7.11. In tank photo processing, washing of images after development (intermediate washing) should be carried out for 0.5 - 1.0 minutes in a 2 - 3% aqueous solution of acetic acid or in running water, the first washing after fixation - 1 - 2 minutes in still water, which, together with the spent fixer, is subject to delivery for the extraction of silver, final washing - 20 - 30 minutes in running water.

7.12. The temperature of the washing water must comply with the recommendations of the film manufacturer, the water consumption during the final washing should be at least 1 liter per 1 minute.

7.13. Dry radiographic images in air at a temperature of 18 to 25 °C or in a ventilated and heated oven to a temperature not exceeding 35 °C.

7.14. For more full use photosolutions when they are depleted, reducing additives recommended by the film manufacturer can be used. The composition of the reducing solution for the X-ray developer and recommendations for its use are given in reference Appendix 5.

7.15. A list of possible image defects caused by violations of photo processing processes is given in reference Appendix 6.

7.16. The results of film testing, preparation of photo solutions, preparation and application of reducing additives to photo solutions are recorded in journals, the form of which is given in mandatory appendices 7 and 8.

7.17. Photoprocessing reagents must have the manufacturer's mark or label, undamaged packaging, and not past the expiration date.

7.18. The use of expired reagents is allowed only after checking their chemical composition for compliance with technical specifications (standards) or checking photo solutions from them according to a methodology agreed with the lead material science organization.

8. IMAGE INTERPRETATION

8.1. Pictures should be interpreted in a darkened room specially designed for this purpose.

8.2. For decoding, negatoscopes with continuously adjustable brightness and adjustable size of the illuminated field should be used.

The maximum brightness of the illuminated field should be at least 10 D+2 cd/m2, where D is the optical density of the image. The dimensions of the illuminated field should be adjusted using movable shutters or mask screens within such limits that the illuminated field is completely covered by the image.

8.3. To measure the optical density of images, densitometers or microphotometers should be used that provide the ability to measure optical density in transmitted light from 0 to 4.0 with an accuracy of no worse than 0.1.

8.4. When the optical density of images is not more than 3.5, it is allowed to assess the compliance of their optical density with the requirements of this technique by visual comparison with a set of measures of optical density. In this case, it is allowed to use sets with optical density values ​​of 1.0; 1.5; 3.5 (with a tolerance of ± 5% for each of the optical density values ​​listed). The sizes of steps with the listed values ​​of optical density should not be less than 20 × 20 mm.

8.5. Photographs approved for decoding must meet the following requirements:

There should be no spots, stripes, contamination or damage to the emulsion layer on the image of the seam and the controlled near-seam zone;

The photographs must show clear images of limit marks, markings and sensitivity standards (except for the cases provided for by this method when the control is carried out without the installation of limit marks or marks, or sensitivity standards, or both);

The optical density of images of the inspected sections of the weld and the near-weld zone, as well as the sensitivity standards should not be less than 1.5 and more than 3.5 ;

The decrease in the optical density of the image of the seam and the controlled near-weld zone in any part of this image in relation to the optical density of the image of the sensitivity standard (or the area where the wire sensitivity standard is installed) should not exceed 1.0;

The sensitivity of the control, determined by the image of the sensitivity standard (the minimum depth of the groove of the groove standard or the minimum diameter of the wire of the wire standard, visible in the picture), must meet the requirements of PNAE G-7-010-89.

8.6. It is allowed to decode images that do not have an image of the sensitivity standard, in the cases provided for in clause 4.14.

8.7. The quality of welds of variable cross-section according to duplicate photographs made on films with different sensitivities is evaluated by individual sections of the images of such welds in these photographs, provided that the optical density of these sections meets the requirements of clause 8.5.

8.8. To measure the dimensions of cracks, lack of penetration, pores and inclusions (their dimensions are taken as the dimensions of their images in the images), when deciphering the images, you should use:

Measuring rulers with a division price of 1.0 mm;

Measuring magnifiers with 10x magnification and 0.1 mm graduations;

Transparent measuring stencils and templates.

8.9. The dimensions measured during the interpretation of images should be rounded to the nearest values ​​from the range 0.2; 0.3; 0.4; 0.5; 0.6; 0.8; 1.0; 1.2; 1.5; 2.0; 2.5; 3.0; 3.5 and 4.0 mm, or the nearest whole number in millimeters for measured dimensions over 4.0 mm.

8.10. When inspecting welded joints of dissimilar materials, welded joints made on a backing ring (plate, mustache, etc.), as well as welded joints made with austenitic welding materials, dark stripes can be detected in the images, which by their nature cannot be unambiguously interpreted as images of lack of fusion. When deciphering such images, one should be guided by the methodological instructions given in mandatory Appendix 9.

9. DOCUMENTATION REQUIREMENTS

9.1. The control results should be recorded in the control results log.

Registration is subject to:

Number (code) of the object (product); name and number of overlay or welded joint; numbers of controlled areas;

Number of technological control card;

Image labeling;

Surname, number or conditional code of the flaw inspector who performed the inspection (if they are not included in the image marking in accordance with the system adopted at the enterprise);

The thickness by which the quality of the welded joint or surfacing is evaluated in accordance with the Control Rules;

Actual control sensitivity;

Identified during the control of discontinuities and their sizes;

Compliance of the welded joint or surfacing with the requirements of PNAE G-7-010-89;

Date of decoding of the images, name and signature of the decoder, number and date of issue of the conclusion.

The form of the journal is established by the enterprise exercising control.

9.2. The test results log must have continuous page numbering, be bound and sealed with the signature of the head of the non-destructive testing service. All corrections in the journal must be confirmed by the signature of the head of the non-destructive testing service.

The journal must be stored at the enterprise in the archive of the non-destructive testing service for at least 5 years.

9.3. Based on the entries in the control results log, a conclusion is drawn up, the form of which and the minimum amount of mandatory information on the control results are given in the recommended Appendix 10.

Other additional information provided for by the system adopted at the enterprise may also be entered in the journal and in the conclusion.

9.4. When filling out the journal and drawing up a conclusion, defects and sizes of defects provided for by the Control Rules are subject to fixation, while symbols in accordance with GOST 7512-82 must be used. If there are no images of defects in the image, it is allowed to use the abbreviation DNO instead of the words “no defects found”.

10. STORAGE OF RADIOGRAPHIC FILM. STORAGE AND DISPOSAL OF RADIOGRAPHIC IMAGES AND FIXING SOLUTION

10.1. Storage of radiographic film and images should be carried out in accordance with the requirements of the manufacturers of radiographic film. In the absence of such requirements, the requirements of this section should be followed.

10.2. Radiographic film and processed images should be stored in a dry, ventilated room at a temperature of 14 - 22 °C and a relative humidity of 50 - 70%. Unexposed film should be stored on racks in a vertical position (on edge), located at a distance of at least 1 m from heaters, at least 0.2 m from the floor and should be protected from direct sunlight.

The height of stacks of images when stored in a horizontal position should not exceed 200 mm. Photographs should be stored in special cabinets or on racks in strict order and in accordance with the entries in a special journal.

10.3. The room for film storage does not allow the presence of radioactive sources, as well as gases harmful to the film: hydrogen sulfide, ammonia, acetylene, carbon monoxide, mercury vapor, etc.

10.4. Do not store radiographic images and film together with chemicals used for photo processing.

10.5. Destruction of radiographic images after the expiration of the storage period, as well as defective films and the collected fixing solution, is carried out in accordance with the Regulations on the procedure for acceptance and processing of scrap and waste of precious metals, as well as on the procedure for settlements with deliverers for accepting precious metals from them in the form of scrap and waste .

11. METROLOGICAL SOFTWARE

11.1. Groove sensitivity standards and samples imitating the concavity and convexity of the weld root must be certified by the metrological service of the manufacturer and be verified by the metrological service of the enterprise using them or a third-party organization at least once every five years.

11.2. Wire sensitivity standards are not subject to verification during their use. These standards should be withdrawn from circulation in case of any damage to the protective plastic cover or if visual inspection reveals traces of corrosion on the wires of the standard.

11.3. Densitometers used to measure the optical density of images must have a passport, which must indicate the limits and accuracy of optical density measurement.

Densitometers must be verified at least once every two years, indicating in the passport the date and results of verification, as well as the company that carried out the verification.

11.4. Negatoscopes used in the interpretation of images must have a passport, which must indicate the maximum brightness of the illuminated field of the negatoscope.

Negatoscopes are not subject to verification.

11.5. Standard means of measuring linear dimensions used in the interpretation of images (rulers, measuring magnifiers) are subject to verification in accordance with GOST 8.513-84.

11.6. Non-standard means of measuring linear dimensions used in the interpretation of images (templates, stencils, etc.) must have identification numbers and certificates, which must indicate the limits of the measured dimensions and the error in their measurement. These funds are subject to verification at least once a year, indicating in the certificate the date of verification and the company that carried out the verification.

11.7. Step sets of optical density samples used to evaluate the optical density of images must have identification numbers and certificates, in which the optical density of the samples must be indicated.

The sets are subject to verification at least once every two years, indicating in the certificate the date of verification and the company that carried out the verification.

12. RADIOGRAPHIC CONTROL UNDER RADIATION BACKGROUND

12.1. The presence of a radiation background during radiographic inspection of welded joints creates an additional photographic veil on a radiographic image, which reduces the image contrast of defects and worsens their detection.

12.2. During radiographic control under radiation background conditions, protective cassettes should be used, which are open on one side to the radiation flux from the working source, which makes it possible to partially neutralize the effect of the radiation background on the radiographic film.

12.3. The radiation source for testing welded joints under radiation background conditions should be selected according to Table. 4 taking into account the exposure dose rate of background radiation.

12.4. The ratio of the exposure dose rate of the radiation background and the working source of radiation behind the absorber should not exceed unity.

12.5. The optical density of the veil of the radiographic image from the known value of the exposure dose of radiation should be determined using Fig. 6.

12.6. The optical density of a radiographic image obtained under background radiation conditions should not be less than 2.0.

12.7. Radiographic images obtained under background radiation conditions should be viewed on a high-brightness negatoscope with adjustable brightness of a matte screen within 10 4 - 10 6 cd/m 2 .

12.8. The deterioration in the sensitivity of a radiographic image obtained under radiation background conditions should not exceed the value indicated in Table. eight.

12.9. For radiographic control under radiation background conditions, it is not allowed to use radiographic film with an initial veil of more than 0.2 units. optical density.

Rice. 6. The dependence of the optical density of radiographic films on the exposure dose:

1 - radiographic film RT-1 with a screen; 2 - radiographic film RT-1; 3 - radiographic film RT-5 with a screen; 4 - radiographic film RT-5

12.10. Background calculation example:

Assess the sensitivity of radiographic control under the radiation background under the following conditions:

Translucent thickness of steel .............................................. 6 mm

Radiation source .............................................................. ............... Iridium-192

Radionuclide activity .............................................................. ..... 333.0 GB to

(5 g-eq. radium)

The exposure dose rate of background radiation..... 2.58? 10 -7 A/kg

(1000 µR/s)

Focal length................................................ ............. 30 mm

Type of radiographic film .............................................. RT- one

Lead shields thickness .................................................................. 0.09 mm

Under normal conditions (without radiation background) when transilluminating steel 6 mm thick by the specified source with focal length 300 mm exposure time is about 1 min. Using fig. 6, we find the value of the veil of the radiographic image - about 0.6 units. optical density. With such a veil, the coefficient of deterioration in the sensitivity of the image is 1.25. If the absolute sensitivity of the image according to the groove standard GOST 7512-82 under normal conditions was 0.3 mm, then under the conditions of background radiation with an exposure dose rate of 2.58? 10 -7 A / kg (1000 μR / s) it will be equal to 0.38 - 0.40 mm.

Table 8

Shot veil, pcs. optical density	Exposure dose of background radiation, C/kg (R)		Radiographic image desensitization factor
	for film RT-1	for RT-5 film
	5.16? 10 -5 (up to 0.20)	4.13? 10 -4 (up to 1.60)
	5,16 ? 10 -5 - 1,16 ? 10 -4 (0,20 - 0,45)	4,13 ? 10 -4 - 9,68 ? 10 -4 (1,60 - 3,75)
	1,16 ? 10 -4 - 21,55 ? 10 -4 (0,45 - 0,60)	9,68 ? 10 -4 - 1,60 ? 10 -3 (3,75 - 6,20)
	1,55 ? 10 -4 - 2,06 ? 10 -4 (0,60 - 0,80)	1,60 ? 10 -3 - 2,18 ? 10 -3 (6,20 - 8,50)

13. SAFETY REQUIREMENTS

13.1. The main hazards for personnel during radiographic control are exposure to the body of penetrating radiation and harmful gases formed in the air under the influence of radiation, and electric shock.

13.2. Radiographic control and recharging of radioactive sources should be carried out only using equipment specially designed for this purpose and in good condition.

13.3. The electrical equipment of existing stationary and portable installations for radiographic control must comply with the requirements of GOST 12.2.007-75 and the Electrical Installation Rules.

13.4. During the operation of stationary and portable installations for radiographic control connected to an industrial electrical network, safety of work must be ensured in accordance with the requirements of the Rules for the Technical Operation of Consumer Electrical Installations and the Safety Rules for the Operation of Consumer Electrical Installations.

13.5. When conducting radiographic control, receiving, storing and recharging radioactive sources of gamma radiation, work safety must be ensured in accordance with the requirements of the Basic Sanitary Rules for Working with Radioactive Substances and Other Sources of Ionizing Radiation OSP-72/87, Radiation Safety Standards NRB-76/87 , Sanitary rules for radioisotope flaw detection, Sanitary rules for X-ray flaw detection and Sanitary rules for placement and operation of electron accelerators with energies up to 100 MeV.

13.6. When transporting radioactive sources of gamma radiation, the requirements of the Safety Rules for the Transportation of Radioactive Substances PBTRV-73 must be observed.

13.7. In accordance with the requirements of this section, enterprises performing radiographic control develop safety instructions for conducting radiographic control, receiving, storing and recharging radioactive sources, eliminating possible emergencies, taking into account local production conditions, and bring them to the attention of personnel in the prescribed manner.

Reference Appendix 11 gives a list of GOSTs that are referenced in this methodology.

Sample flow chart for radiographic inspection

Product number and code

Name of the welded joint

Weld number

________________________________________

________________________________

Map developer

_______________________________________

(Signature, date, last name)

Head of the department exercising control

_______________________________________

(Signature, date, last name)

APPENDIX 2

(mandatory)

Method for assessing the concavity and convexity of the root of the seam when they are not available for external examination

1. The concavity and convexity of the root of the weld during the control of welded joints of pipelines with a diameter of 30 mm or less is estimated by measuring the size of the image of their profile on the side (with respect to the direction of transmission) walls of the pipelines in the images.

2. The concavity and convexity of the root of the weld during the control of welded joints of pipelines and other products with a diameter of more than 30 mm is assessed by visual (or using a densitometer) comparison of the optical density of their image in the image with the optical density of the image of the groove or protrusion on the steel imitator sample shown below .

3. Depth h 1 groove and height h 2 protrusions of the imitator specimen must be equal to the maximum allowable values ​​of the concavity and convexity of the root of the weld. Width a grooves and width b protrusions should be equal to rounded up to the nearest higher integer value (in millimeters), twice the maximum allowable values ​​for the concavity and convexity of the root of the weld. Thickness h 3 of the simulant specimen should be equal to the magnitude of the reinforcement of the controlled seam.

Tolerances for all dimensions of the sample - simulator ± 10%.

4. It is allowed to use imitation samples with grooves and protrusions of a semicircular shape with a radius equal to the limit value of the concavity and convexity of the root of the weld.

5. It is allowed to use separate samples imitating the concavity and convexity of the root of the weld (sample - imitator of concavity and sample - imitator of the convexity of the root of the weld).

6. It is allowed to use imitation specimens with a thickness h 3 less than the reinforcement of the seam. In this case, the simulant sample should be installed on a gasket that compensates for the difference between the thickness of the simulant sample and the value of the weld reinforcement.

7. The imitator should be installed on the controlled welded joint on the side of the radiation source at a distance of at least 5 mm from the weld. If it is impossible to install the imitator sample from the side of the radiation source, it is allowed to install it from the side of the radiographic film.

8. The optical density of the image of the imitator sample in the picture should be equal to the optical density of the image of the seam.

9. To improve the accuracy of assessing the concavity and convexity of the weld root, as well as if it is impossible to fulfill the requirement of clause 8, it is recommended to carry out a primary inspection of the welded joint without installing a simulator sample.

If concavity or convexity of the root of the weld is detected during the initial inspection and it is necessary to assess their magnitude, a second inspection of the areas is carried out, in the image of which images of the concavity or convexity of the weld are revealed. During the re-inspection, the imitator specimen should be installed directly on the seam with the direction of the groove (protrusion) across the seam.

10. The concavity or convexity of the weld root does not exceed the maximum permissible value, if the optical density of the image of the concavity in the image is less, and the convexity is greater than the optical density of the images imitating their grooves or protrusions on the imitator sample.

Note. When the imitator sample is installed directly on the seam, the optical densities of the areas of the concavity (convexity) and groove (protrusion) images of the imitator sample located in the immediate vicinity of the intersection of these images are compared.

Selection of the distance from the radiation source to the controlled welded joint and the length or number of controlled sections

1. For schemes of the type shown in fig. 2 distance f from the source of radiation to the controlled welded joint and length L area controlled for one exposure must satisfy the ratios

f ? ch; L ? 0,8f, where c= 2F/K at F/K? 2 and c = 4 at F/C< 2; h- radiation thickness of the controlled area, mm; Ф - the maximum size of the focal spot of the radiation source, mm; K - required control sensitivity, mm.

2. For the schemes of fig. 3, a, d, e during control with the location of the radiographic film along the diameter of the inspected welded joint (the length of the film is equal to the inner diameter of the welded joint) distance f from the radiation source to the controlled welded joint should not be less than the values ​​determined by the formulas given in Table. P3.1.

Note. If determined according to the table. A3.1 formulas for minimum distances f negative, minimum value f is taken equal to zero, i.e. The source can be installed directly on the surface of the controlled item.

Table A3.1

Note. D and d- outer and inner diameters of the controlled welded joint, mm.

3. After choosing a distance f the ratio is determined f/D and depending on the value of this ratio according to the table. P3.2 - P3.4 find the number of sites N, on which the welded joint should be marked (number of exposures required for 100% control).

Note. It is allowed to determine according to the table. P3.2 - P3.4 value f depending on the number of plots selected from these tables, provided that this value meets the requirements of Table. P3.1.

Table A3.2

d/D	The number of sites during the control according to the scheme of fig. 3, a
	f/D, not less

4. For the scheme of fig. 3, in distance f and the number of sections (exposures) must satisfy the relations f ? c · D; N ? 2.

5. For the scheme of fig. 3b for the radiographic film length less than the internal diameter of the welded joint, as well as for the circuits in Fig. 3, w, h distance f and number N plots (exposures) are determined empirically, taking into account the requirements of the methodology.

Fig. 6. Angle between radiation directions for individual exposures when controlled according to the schemes of fig. 3, a, b, d, e, g, h should be 360 ​​° / N± 3°.

Fig. 7. Angle between radiation directions for individual exposures when controlled according to the scheme of fig. 3, in must be 180°/ N± 3°.

8. For the scheme of fig. 4, d distance f and the length of the radiographic film are chosen in the same way as for the scheme of Fig. 3, c, control of the welded joint according to the scheme of fig. 4e is carried out in one exposure.

Determination of exposure time during X-ray control and gamma-graphic control using sources of iridium-192 and cobalt-60

1. To determine the exposure time during X-ray control and gamma-graphic control using sources of iridium-192 and cobalt-60, using a steel stepped or wedge-shaped sample, the time is experimentally determined t 0 , necessary to obtain a given optical density of the image when transilluminating a sample area with an arbitrary radiation thickness h 0 (with X-ray control - at a given voltage on the X-ray tube).

2. After the definition t 0 (this time must be determined for each specific type of X-ray machine and type of radiographic film separately), the exposure time required to obtain a given optical density of images when transilluminating a welded joint is determined by the formulas:

under x-ray control

with gamma graphic control

where h 0 and h- radiation thicknesses when determining t 0 and translucence of the welded joint, cm; Q 0 , Q, I 0 and I- source activity and X-ray tube current when determining t 0 and transillumination of the welded joint; F 0 and F- distance from the radiation source to the radiographic film when determining t 0 and transillumination of the welded joint; µ is the linear attenuation coefficient of a wide beam of radiation.

3. The coefficient µ for X-ray machines is found experimentally for each specific type of machine and voltage on the X-ray tube according to the following method: for a given voltage on the X-ray tube, the exposures E 1 and E 2 (mA / min) necessary to obtain a given optical density of images are determined when transilluminating steel with arbitrarily chosen radiation thicknesses h 1 and h 2; the value of µ is determined by the formula

4. The values ​​of µ for cable X-ray machines of the type RAP-150/300 are given in Table. P4.1.

5. The values ​​of µ for sources of iridium-192 and cobalt-60 are given in Table. P4.2.

Table A4.1

Table A4.2

APPENDIX 5

(reference)

The composition of the recovery solution for the developer "X-ray-2"

Notes:

1. The reagents that are part of the reducing solution should be dissolved in distilled water according to GOST 6709-72 at a temperature of 45 ± 5 °C in the above sequence.

2. In 1 liter of the developer "X-ray - 2" without introducing a reducing solution into it, it is allowed to process no more than 1 m 2 of film, with the introduction of a reducing solution - no more than 2.5 m 2 of film.

3. Enter the reducing solution should be at the rate of 0.2 liters per 1 liter of developer after processing the film in it in a volume of 0.4 - 0.5 m 2 per 1 liter of developer.

APPENDIX 6

(reference)

Defects in photo processing of radiographic images

Image defect type	Possible reasons
	Development defects
Dark or light spots	Insufficient agitation of the solution during development
	Illumination of radiographic film
	The presence of salts of copper, tin or salts of other elements in the developer
	Exposure to warm air when taking the image out of solution frequently during development
Yellow or dichroic veil	Depleted developer solution
	Too long exposure
	Too high developer temperature Developer contaminated with fixer
	Fixation defects
Grey-brown spots or streaks	Insufficient fixation
	Exposure to light during fixation
Yellow or dichroic veil	Depleted fixer solution
White dots and spots	Insufficient mixing of the solution during fixation

APPENDIX 7

(mandatory)

Radiographic Film Inspection Log

APPENDIX 8

(mandatory)

Journal of the preparation and recovery of photographic solutions

APPENDIX 9

(mandatory)

Interpretation of images with dark stripes, which by their nature cannot be interpreted as images of lack of fusion

1. When a welded joint of elements made of dissimilar materials, a welded joint made on a backing bar (ring, mustache, etc.), or a welded joint made with austenitic welding material, is detected in the image, a dark strip, which by its nature cannot be unambiguously interpreted as an image of lack of fusion, a metallographic examination of this welded joint is carried out in the area, in the image of which a dark strip is revealed (transverse grinding or layer-by-layer grinding through 0.5 mm with etching and color flaw detection of each layer).

2. If, as a result of the metallographic examination, no internal defects are revealed that could cause the appearance of a stripe in the image, a technical solution is drawn up agreed with the head industry material science organization, according to which similar dark stripes in the images of the same type of welded joints listed in the solution are not considered as rejection a sign when evaluating the quality of these seams according to the results of control, and the image of the area subjected to metallographic examination is used as a sample image when deciphering other images of these seams.

3. In these cases, a reference to the technical solution (indicating its number and date) should be made in the log of control results and the conclusion. This solution, the results of the metallographic solution (an act or protocol, a photograph of a thin section, etc.) and a reference image must be kept as an attachment to the log of control results for the period established for this log.

The conclusion was

________________________________________

(Signature, date, last name)

Head of laboratory

(head of section, foreman)

________________________________________

(Signature, date, last name)

APPENDIX 11

(reference)

List of standards referenced in this methodology

Designation	Name
GOST 7 512-82	The control is non-destructive. Connections are welded. radiographic method
GOST 24034-80	Non-destructive radiation control. Terms and Definitions
GOST 20426-82	The control is non-destructive. Radiation flaw detection methods. Application area
GOST 8.513-84	State system for ensuring the uniformity of measurements. Verification of measuring instruments. Organization and verification procedure RTM 36.2-87 Guidelines for the use of photographic paper with intensifying screens for quality control of welded joints

2.1. For welded joints of equipment and pipelines of nuclear power plants with pressurized water and water graphite reactors, the following three categories of welded joints are established:

Depending on the operating pressure, welded joints of categories II and III are divided into the following subcategories:

2.2. For welded joints of equipment and pipelines of nuclear power plants with fast neutron reactors with liquid metal coolant, the following categories of welded joints are established:

Iн category - welded joints of equipment and pipelines of group A, as well as welded joints of equipment and pipelines of group B with special requirements for ensuring tightness established by design documentation;

Depending on the specific operating conditions, welded joints of IIн, II and III categories are divided into the following subcategories:

subcategory IIInv - welded joints in contact with a liquid metal coolant and/or gas at temperatures up to 350 °C inclusive, regardless of pressure (with the exception of those belonging to subcategory IInv);

2.3. Edge welding is in the same category as the corresponding weld.

2.4. Anti-corrosion surfacing is considered independently without assigning it to any category.

2.5. Categories of welded joints are assigned by the design (design) organization in accordance with the above provisions and are indicated in the design (project) documentation.

2.6. By decision of the design (project) organization, agreed with the manufacturer (installation organization), some of the most critical welded joints located in places of stress concentration can be transferred to a higher category.

Introduction date -
June 1, 1990
(Resolution
Gospromatomnadzor of the USSR
dated January 5, 1990 N 1)

EQUIPMENT AND PIPELINES OF NUCLEAR

POWER PLANTS

WELD JOINTS AND SURFACES

CONTROL RULES

PNAE G-7-010-89

(with Amendments No. 1 of 09/01/2000)

These Control Rules (PC) establish requirements for the control of welded joints and welded parts ( assembly units, products) equipment and pipelines nuclear power plants, heat supply stations, combined heat and power plants, experimental and research nuclear reactors and installations, which are subject to the "Rules of the AEU. PNAE G-7-008-89".
These PKs are the guiding material for the design, construction, manufacture, installation of equipment and pipelines and establish the procedure, types, scope and methods of control and standards for assessing the quality of welded joints and welded parts (products) made in accordance with the requirements of the document "Equipment and pipelines of nuclear power plants. Welding and surfacing. Basic provisions. PNAE G-7-009-89".
The control rules were introduced instead of the "Rules for the control of welded joints and surfacing of units and structures of nuclear power plants, experimental and research nuclear reactors and installations PK 1514-72".
Mandatory for all ministries, departments, organizations and enterprises engaged in the design, construction, manufacture, installation and operation of equipment and pipelines that are subject to the Rules for the Arrangement and Safe Operation of Equipment and Pipelines of Nuclear Power Plants.

1. GENERAL PROVISIONS

1.1. The choice of control methods specified in these PKs, and the determination of the scope of control of welded joints and welded parts (including indications of areas of welded joints and weld deposits that are inaccessible to control by any method) are carried out by the design (project) organization, which indicates them in the design documentation, coordinated with the manufacturer (installation organization). When developing design documentation for equipment and pipelines of single and main facilities (the first nuclear power plant of one type series) methods and scope of control of welded joints and welded parts are subject to agreement with the leading material science organization.
Note. The leading materials science organization is understood as the leading branch materials science organization, unless otherwise specified in the text.

1.2. Design (project) documentation ( technical project and working documentation) for equipment and pipelines should be developed taking into account the need to control welded joints and welded parts in accordance with the requirements and guidelines of these PKs and regulatory and technical documents on control methods.
1.3. The location and design of welded joints and welded parts must meet the requirements of the design (design) documentation, made in accordance with PNAE G-7-008-89 and PNAE G-7-009-89, and provide the ability to control these joints and parts by methods and in the volumes provided for by these PKs in the manufacture, installation and repair of equipment and pipelines.
1.4. Each method should be controlled according to state standards on the relevant methods of control or methodological industry standards specifying the methods of control of welded joints and welded parts. In the absence of these standards, it is allowed to carry out control according to the methodological instructions developed by the leading materials science organization. The use of the mentioned standards or instructions must be approved by the USSR Gosatomenergonadzor.
1.5. All preparatory and control operations should be included in the production control documentation (PKD) (control cards, instructions, etc.) and provided with the necessary controls.
The PKD must be agreed with the leading materials science organization.
It is allowed to combine PKD with production and technological documentation (PTD).
1.6. All operations for the control of welded joints and welded parts provided for by these PK, design documentation, PDD and PKD must be carried out by the manufacturer (installation organization) performing welding (or specialists of other organizations involved by this enterprise) in the sequence established by the PDD of this enterprise, with taking into account the requirements of these PCs.
1.7. The results of the control of welded joints and overlays must be recorded in the reporting documentation.
1.8. In case of non-compliance with the established requirements and standards, welded joints and welded parts are subject to correction or are rejected.
The issue of the possibility of admitting welded joints (surfacing) with discontinuities, the indicators of which exceed the standards established by these PKs, is resolved in the manner specified in Sec. fourteen.
1.9. Quality control of welded joints and overlays includes:
- certification of controllers;
- control of assembly-welding and thermal equipment, apparatus and fixtures;
- input control of basic materials;
- quality control of welding and surfacing materials;
- operational control;
- unbrakable control;
- destructive control;
- quality control of defect correction;
- hydraulic (pneumatic) tests.
1.10. Attestation of controllers includes checking their theoretical knowledge and practical skills.
1.11. The control of assembly and welding equipment, apparatus and fixtures includes checking the serviceability of their condition, as well as the necessary equipment with measuring and control equipment.
1.12. Input control of basic materials must be carried out in accordance with the instructions of Sec. 3 PNAE G-7-008-89.
The control of cast parts in areas adjacent to the edges of the groove for welding should be carried out in accordance with the "Rules for the control of steel castings for nuclear power plants".
The base materials to be welded must be heat treated in accordance with the requirements of standards or specifications for the supply of materials, and in case of additional requirements in the drawings or specifications on the product - in accordance with these requirements.
If corrosion-resistant austenitic steel undergoes additional heat treatment during the construction process, it is necessary to re-check its mechanical properties and resistance to intergranular corrosion.
By agreement with the leading materials science organization, this check can be omitted, replacing it with the control of the correct implementation of the heat treatment mode.
1.13. Quality control of welding and surfacing consumables includes verification of documentation, assessment of the state of packaging and external condition, destructive testing of the weld metal and/or deposited metal made by controlled materials.
1.14. Operational control covers verification of compliance with PDD requirements during preparation and assembly for welding (surfacing), heating, welding (surfacing) and heat treatment.
1.15. Non-destructive testing includes the following methods:
- visual;
- measuring;
- sweeping with a metal caliber (ball);
- capillary;
- magnetic particle;
- radiographic;
- ultrasonic;
- tightness control.
In addition to the above basic methods, in cases provided for by the design documentation or design documentation, additional methods can be applied (steeloscopy, hardness measurement, etching, etc.).
1.16. During destructive testing, mechanical tests are carried out (tensile test at normal temperature, tensile test at elevated temperature, static bending test, pipe flattening test), determination of the ferrite phase, tests for intergranular corrosion, metallographic studies, determination of chemical composition.
1.17. Welded joints as part of structures or individual assembly units must be subjected to hydraulic (pneumatic) tests in accordance with the instructions of the design documentation.
1.18. Definitions of terms and basic concepts found in the text of these SCs are given in Appendix 1.

2.1. For welded joints of equipment and pipelines of nuclear power plants with pressurized water and water graphite reactors, the following three categories of welded joints are established:
I category - welded joints of equipment and pipelines of group A;
II category - welded joints of equipment and pipelines of group B, operating continuously or periodically in contact with radioactive coolant;
Category III - welded joints of group B equipment and pipelines that do not work in contact with radioactive coolant, as well as welded joints of group C equipment and pipelines.
Depending on the operating pressure, welded joints of categories II and III are divided into the following subcategories:
- subcategory IIa - welded joints operating under pressure over 5 MPa (51 kgf / sq. cm);
- subcategory IIc - welded joints operating under pressure up to 5 MPa (51 kgf / sq. cm) inclusive;
- subcategory IIIa - welded joints operating under pressure over 5 MPa (51 kgf / sq. cm);
- subcategory IIIc - welded joints operating under pressure over 1.7 MPa to 5 MPa (over 17.3 to 51 kgf / sq. cm) inclusive;
- subcategory IIIc - welded joints operating under pressure up to 1.7 MPa (17.3 kgf / sq. cm) and below atmospheric pressure (under vacuum).
2.2. For welded joints of equipment and pipelines of nuclear power plants with fast neutron reactors with liquid metal coolant, the following categories of welded joints are established:
- Iн category - welded joints of equipment and pipelines of group A, as well as welded joints of equipment and pipelines of group B with special requirements for ensuring tightness established by design documentation;
- IIн category - welded joints of equipment and pipelines of group B, operating in contact with liquid-metal coolant and gas (with the exception of those belonging to category Iн);
- II category - welded joints of equipment and pipelines of group B, not working in contact with liquid metal coolant and gas;
- III category - welded joints of equipment and pipelines of group C.
Depending on the specific operating conditions, welded joints of IIн, II and III categories are divided into the following subcategories:
- subcategory IIna - welded joints in contact with a liquid metal coolant and / or gas, operating at temperatures above 350 ° C, regardless of pressure;
- subcategory IIInv - welded joints in contact with a liquid metal coolant and/or gas at temperatures up to 350 °C inclusive, regardless of pressure (with the exception of those belonging to subcategory IInv);
- subcategory IIIns - welded joints in contact with gas and operating at a pressure of 0.07 MPa (0.71 kgf / sq. cm) inclusive and temperatures up to 150 °C inclusive;
- subcategory IIa - welded joints that are not in contact with liquid metal coolant and gas, operating at an operating pressure of more than 2 MPa (20.4 kgf / sq. cm);
- subcategory IIc - welded joints that are not in contact with the liquid metal coolant, operating at an operating pressure of up to 2 MPa (20.4 kgf / sq. cm) inclusive;
- subcategory IIIa - welded joints operating at a working pressure of more than 5 MPa (51 kgf / sq. cm);
- subcategory IIIc - welded joints operating at an operating pressure of over 1.7 to 5 MPa (over 17.3 to 51 kgf / sq. cm) inclusive;
- subcategory IIIc - welded joints operating at operating pressures up to 1.7 MPa (17.3 kgf / sq. cm) and below atmospheric pressure (under vacuum).
2.3. Edge welding is in the same category as the corresponding weld.
2.4. Anti-corrosion surfacing is considered independently without assigning it to any category.
2.5. Categories of welded joints are assigned by the design (design) organization in accordance with the above provisions and are indicated in the design (project) documentation.
2.6. By decision of the design (project) organization, agreed with the manufacturer (installation organization), some of the most critical welded joints located in places of stress concentration can be transferred to a higher category.