Method of quality control of welded joints of heat-generating element
Method of quality control of welded joints of heat-generating element is intended for use in the field of nuclear energy. The method consists in the emission of the ultrasonic signal. Ultrasonic signal piezoelectrically falls normally to the outer surface of the fuel element and the surface of the weld when moving along its generatrix. Complete the registration of the echo signals from the inner and outer surface of the shell and weld in the area of line continuation of the inner surface of the shell over time. It provides detection of penetration, pores, micropores, the length of the zone of the integrity and reliability of their detection. 1 Il.The invention relates to non-destructive methods for quality control of welds, namely, ultrasonic testing sealing welds fuel element for nuclear reactors VVER-1000, VVER-440, in which the welds are made pin-butt welding (CSS-2) and the electron-beam welding (ELS).There is a method of ultrasonic inspection of the weld pin-butt welding stub to the fuel cladding, including testing in demetropoulou during the rotation of the fuel element and the movement of the transmitter and receiver of ultrasonic pulses in the axial direction of the weld joint area of the fuel element, recording the results of the control and determination section length fusion in the direction of the axis of fuel element (“Development, production and operation of fuel cell power reactors”. /Ed. by F. G. Reshetnikov, kN.2, M.: Energoatomizdat, 1995, S. 274-276, and Fig.21.12. Schematic of ultrasonic inspection of welded joints made contact butt welding KCC-2).The disadvantage of this method is the lack of detection of pores in the region of the line of continuation of the inner surface and penetration, determined by the length of the continuation of the inner surface.The closest in technical essence and the achieved result is a prototype method of ultrasonic testing of the weld by the RF patent №2158031 “Method of ultrasonic testing of the weld pin-butt welding stub to the fuel cladding”, IPC G 21 17/07, 21/00, 2000, including the testing of the ultrasonic beam welded joint, receiving ultrasonic pulses at discrete rotation of the fuel element and line-by-line reciprocating movement of the radiating and receiving piezoelectric transducers in the axial zone of the ia in the direction of the axis of the fuel element.The disadvantage of this method is the lack of detection of pores in the region of the line of continuation of the inner surface and penetration, determined by the length of the continuation of the inner surface.Object of the invention is the identification of poor penetration, pores, micropores, the length of the zone of the integrity and reliability of detection.The task is solved in that a method of quality control of welded seams fuel element consists in the emission of the ultrasonic signal, its reception and analysis, according to the formula of the invention the ultrasonic signal transducer impinges normal to the outer surface of the fuel element and the surface of the weld while moving it along the surface and record the echo signals from the inner and outer surface of the membranes and in the line of continuation of the inner surface of the shell at the time, duration and extent of an observation.This set of features is new and involves an inventive step, because the method allows to evaluate the quality of sealing of welded joints shell plugs fuel elements made of electron-beam welding and contact-butt welding (KCC - through ultrasonic signal normal to the surface of the shell and weld and additional use of the echo signals from the undercut stubs for electron beam welding and bottom signal for pin-butt welding (CSS-2).The drawing shows a diagram of the method for quality control of the weld heat-generating element, in which an I - diagram of the scanning of the weld of the first stub made of electron-beam welding II - diagram of the scanning of the weld of the second stub made contact butt welding (CSS-2).The method is implemented as follows.TVEL is served in the immersion bath of the rotation mechanism. After installation of a fuel rod at the position of the control and signal source status command to the personal computer starts the reciprocating movement of piezoelectrically (PEP) along the axis of the fuel rod and subsequent rotation of the fuel rod at a given angle after each move, and personal computer remembers the current position of the moving probe and the angle of rotation of the fuel rod.At the same time starts the pulse generator, connected to the probe, and the ultrasonic signals generated by the transducers, prosvechivayut membrane of a fuel rod and welded connection. Echo signals reflected from the surfaces of the fuel elements and discontinuities, accepted the probe and amplified in the amplifier for further processing in a personal computer and surveillance on the screen of the cathode-radiology is m piezoelectric, for example, the focusing, the inverter 1 via the immersion liquid falling normal to the outer surface 2 of the casing of a fuel rod. Reflected from the outer surface 2 of the echo signals of 3 are recorded ultrasonic flaw detector 4 and the screen of the cathode ray tube (CRT) 5 see echoes 3. The ultrasonic vibration is held in the sheath material, reflect from the inner surface 6. The reflected echo signals from the inner surface 6 register ultrasonic flaw detector 4 and the CRT screen see echoes 7.The duration of strobe 12 detector 4 is installed between the signals 3 and 7. When moving the piezoelectric transducer 1 along the generatrix of TVEL recorded echo signals 3 and 7 ultrasonic flaw detector 4 and remember synchronously with the movement in the PC memory 16.When switching on weld continued registration of echoes 3, set the duration of strobe 12 provides registration of defects in welded joints 9 or 10 above the line 11 continuation of the inner surface. The amplitude and width of the echo signals caught in the strobe-pulse 12 detects faults: pores, lack of penetration, and the length of the observation time of the signal determines edenia probes produce again this is repeated until a complete rotation of the fuel rod at the angle of 360C. Echo each line remember. After the disappearance of the echo signal 7 from the inner surface 6 begins extent of continuity, as in the weld and in the absence of incomplete fusion is receiving echo signals from the second strobe pulse 19, installed in a specific location. For a welded joint 9 ELS in place of the 3rd reflection echo signal 7, you receive an echo signal 13 that is reflected from the surface 14 of the undercut, which carries additional information about the quality of a welded joint: it informs about the lack of lack of fusion, and interrupt - on the presence of pores, for a welded joint 10 KCC-2 - echoes 15 reflected from the opposite surface of the blank. Its presence informs about the quality of a welded joint and its length, and interrupt - on penetration and micropores.Thus, the application of this method allows to increase quality control and, consequently, the reliability of the fuel element.
ClaimsMethod of quality control of welded joints of heat-generating element, consisting in the emission of the ultrasonic signal, its reception and Ana is poverhnosti fuel element and the surface of the weld while moving it along the surface and record the echoes from the outer and inner surface of the shell and weld in the area of line continuation of the inner surface of the shell at a time the duration and the extent of the surveillance.
FIELD: nuclear engineering.
SUBSTANCE: the proposed invention is related to the ultrasonic methods of testing for detection of failed fuel elements and may be used when checking the lead-proofness of the fuel elements at spent fuel assemblies, being in water. The proposed methods includes excitation of ultrasonic waves in the fuel element can, detection of the useful reflected and twice reflected signals and determination of the nonleak-proofness when using the amplitude of the useful reflected signal. As a preliminary the ultrasonic waves are excited in the can of an air-tight fuel element or in its simulator by means at a transducer. In this case the wave frequency increases from 0.25 MHz. The value of the frequency of, at which the twice reflected signal is not detected, is determined. Then the ultrasonic waves at the frequency of are excited in the can of a tested fuel element and the conclusion is made on its nonleak-proofness.
EFFECT: increased sensitivity and reliability at detection of failed fuel elements.
3 cl, 10 dwg
FIELD: atomic power engineering; registration systems of leaks of the heating carrier of the 1-st loops of the reactor facilities of nuclear electric power plants.
SUBSTANCE: the invention is pertaining to the field of atomic power engineering and may be used in at the reactor installations with the water-to-water and water-graphite reactors, in particular, at a decompression of the 1-st loop. The registration system of leaks of the heating carrier of the 1-st loops of the reactor facilities of a nuclear electric power plant contains a block of the controlled rooms with equipment of the 1-st loop of the reactor installation connected through air ducts of exhaust ventilation with a block of the channels intended for measuring of relative humidity of the air in the controlled rooms, that includes a reference channel intended for measuring of relative humidity of outdoor air in the rooms with the measuring channels. Sensor units of measuring channels are connected to a control unit for recording and matching of the parameters of the relative humidity of the air in the controlled rooms and in the room with the measuring channels, each of which is made in the form of an expander, on one butt of which there is a branch pipe with a filtering tool connected with the air duct, and on the other butt there is a flange intended for mounting of a sensor. At that outside of the expander there is a cooling chamber. The invention allows to simplify the process of the control over the indications of the relative humidity of the air in the controlled rooms and to improve reliability of operation of the reactor installation by well-timed detection of a location and intensity of the leakage of the heating carrier.
EFFECT: the invention ensure simplified control over the indications of the relative humidity of the air in the controlled rooms, improved reliability of the reactor installation operation by well-timed detection of a location and intensity of the heating carrier leakage.
6 cl, 9 dwg
FIELD: shipboard nuclear power plants.
SUBSTANCE: proposed method includes measurement of reference radionuclide-tritium content and calculation of primary coolant leakage. This method is characterized is that air space between primary-circuit equipment and reactor vessel is sealed for locating leaky points. To this end air filled space or hood is organized above suspected point of coolant leakage. Damp air samples are taken from insulated air space and specific activity of reference radionuclide-tritium in damp air is measured, then volumetric activity of tritium in insulated space is calculated up to pressure rise and after its drop within reactor.
EFFECT: facilitated check of flanged joints between primary-circuit equipment and reactor vessel for tightness during hydraulic tests.
FIELD: nuclear engineering; water moderated water cooled reactors and cooling ponds for detecting leaky fuel elements in fuel assemblies.
SUBSTANCE: proposed device for checking tightness of fuel elements in fuel assemblies has rod, submersible pump, flow-type degasifier, and pipes for feeding pure distillate and compressed air. Rod mounts facility for connecting and packing fuel assembly. Flow-type degasifier is made in the form of vessel accommodating partially perforated and axially disposed tube. Degassed water drain pipes as well as air and water discharge pipes are provided in upper part of vessel and pipes for feeding air through bubbling manifold, in its lower part. Invention specification also includes relevant method for checking nuclear reactor fuel elements for tightness.
EFFECT: ability of on-line shooting of leaky fuel elements and evaluation of flaw size in faulty fuel element.
6 cl, 2 dwg
FIELD: nuclear power engineering; checking steam generators of shipboard pressurized-water reactor for tightness during hydraulic tests.
SUBSTANCE: proposed method for checking steam generator of shipboard power plant for tightness includes measurement of reference radionuclide content in primary and secondary coolant samples with reactor shut down followed by calculation of amount of leakage. Primary and secondary coolant samples are taken from each steam generator upon completion of hydraulic tests. Prior to do so, primary-circuit water is stirred. This method provides for unbiased check of steam generator for tightness at low estimation threshold and identifying leaks of any amount.
EFFECT: ability of monitoring each steam generator for condition.
3 cl, 1 tbl