A co-operative project between Belgian Nuclear Research Centre (SCK/CEN) and Ultrasound Institute
Contract No.: CO-90 01 1487/V7606
The objective of the project
In some reactors or accelerator driven systems (ADS) the core will be cooled by means of heavy liquid metal (HLM). For safety and licensing reasons, a visualization method, based on application of ultrasonic waves, has thus to be developed. The Belgian Nuclear Research Centre (SCK/CEN) is designing the ADS system MYRRHA and co-operates with the Ultrasound Institute of Kaunas University of Technology in order to develop an ultrasonic visualization system.
- MYRRHA is an Accelerator Driven System (ADS) providing protons and neutrons for R&D.
- The core of the nuclear reactor is cooled by means of liquid metal Pb/Bi alloy.
- For safety and licensing reasons, a method for imaging under liquid metal has to be developed.
This system will exploit piezoelectric transducers submersed in the liquid lead-bismuth alloy, which will be exposed to very harsh conditions: the temperature will be in range 160-450°C and the gamma dose rate could be up to 30 kGy/h. In addition, the transducers will be subject to liquid metal corrosion. It will be the first ultrasonic visualisation and inspection system in the world, which shall operate in such harsh conditions.
The development of such visualisation system consists of a number of stages – measurement of lead-bismuth (Pb/Bi) properties, development of high temperature ultrasonic transducers, development of an acoustic computer model of MYRRHA reactor, and visualisation methods.
Investigation of Pb/Bi properties
Acoustic properties of liquid lead-bismuth alloy were hardly known, therefore, the scientists of the Ultrasound Institute had to perform fundamental research during which temperature dependencies of ultrasonic wave velocity and wave attenuation in liquid lead-bismuth alloy were measured for the first time in the world and it was experimentally demonstrated that even high frequency ultrasonic waves (5MHz) can be received after they have propagated as much as several meters. The first time in the world acoustic properties of Pb/Bi alloy were measured:
Development of high temperature ultrasonic transducers
During the project implementation, the key elements of the system were developed: primary ultrasonic transducers for ultrasonic wave generation and reception, which are able to operate without cooling in the medium of a chemically hostile liquid metal and intensive radiation. Production technologies of such transducers using diamond-like coatings were created, diffused welding methods for strong piezoceramic element and the metal transducer housing bonding were improved, and new piezoelectric materials were used.
Transducer operation conditions:
- Submersed in liquid lead-bismuth alloy;
- Temperature 130-450°C;
- Exposed to liquid metal corrosion;
- DLC coated protector.
- Selection of piezoelectric materials suitable for operation at elevated temperatures and under strong radioactive irradiation: Piezoceramic bismuth titanate Pz46.
- Acoustic coupling of a piezoelectric element to protector and backing at high temperatures: Diffusion bonding.
- Durable and stable acoustic coupling of an ultrasonic transducer to the liquid metal (Pb/Bi) alloy: Diamond like carbon coating (DLC).
Development of acoustic MYRRHA computer model
The aim of MYRRHA reactor control is to test whether all the elements of the reactor are in place and if their geometry has not changed under the influence of tough conditions. For this purpose, the Belgian Nuclear Research Centre developed a digital model of the reactor describing its geometry. On its basis KTU Prof. K.Baršauskas Ultrasound Research Institute developed an acoustic model of the reactor which enables to foresee what kind of ultrasonic signals will be reflected by the elements of the reactor and what ultrasonic images would be received if the state of the reactor was perfect. Any ultrasonic image deviations received from the acoustic model inform about changes inside the reactor.
The acoustic computer model should allow:
- To simulate interaction of ultrasonic waves with the MYRRHA reactor components;
- To carry out diagnostics of the reactor by comparison of the expected and actually obtained ultrasonic images.
- Geometry of MYRRHA interior is given as set of elementary triangles;
- Numerical simulation is based on calculation of ultrasonic fields scattered by arbitrary oriented in space triangles;
- The complete scattered field is obtained by fusion of ultrasonic fields by all triangles.
- E.Jasiūnienė, R.Kažys, L.Mažeika, A.Gusarov, M.Schyns, M.Dierckx, Ait Abderrahim, Hamid. Acoustic computer model for ultrasonic imaging of heavy liquid metal nuclear reactor // 2010 IEEE International Conference on Imaging Systems and Techniques [elektroninis išteklius] : July 1-2, 2010, Thessaloniki, Greece : proceedings. Piscataway : IEEE, 2010. ISBN 9781424464937. p. 244-247. [IEEE/IEE; 0,143].
- A.Voleišis, R.Šliteris, R.Kažys, B.Voleišienė. Investigation of diffusion bonding quality by ultrasonic technique. Ultragarsas. 2010. Vol. 65. No. 2. p. 17-23. /pdf/
- E. Jasiūnienė, R. Šliteris, L. Mažeika. Experimental verification of the acoustic computer model using triangle reflector. Ultragarsas. 2008. Vol. 63. No. 2. P. 31-35. /pdf/
- R. Kažys, A. Voleišis, B. Voleišienė. High temperature ultrasonic transducers: review. Ultragarsas. 2008. Vol. 63. No. 2. P. 7-17. /pdf/
- E. Jasiūnienė. Investigation of the influence of the transducer positioning angle deviation on the 3D reflections from a triangle reflector. Ultragarsas. 2008. Vol. 63. No. 1. P. 23-26. /pdf/
- E. Jasiūnienė. Modelling of 3D reflections from triangles using the Huygens approach. Ultragarsas. 2007. Vol. 62. No. 4. P. 22-27. /pdf/
- R. Kažys, A. Voleišis, R. Šliteris, B. Voleišiene, L. Mažeika, H. Ait Abderrahim. Research and development of radiation resistant ultrasonic sensors for quasi-image forming systems in a liquid lead-bismuth. Ultragarasas. 2007. Vol. 62. No. 3. P. 7-15. /pdf/
- R.Kažys, L.Mažeika, A.Voleišis, R.Šliteris, E.Jasiūnienė, H.Ait Abderrahim, M.Dierckx. Ultrasonic imaging in the liquid metals. International Journal of Applied Electromagnetics and Mechanics. Amsterdam: IOS Press. ISSN 1383-5416. 2007. Vol. 25. No. 1-4, p. 249-256. /pdf/
- E.Jasiūnienė, R.Kažys, L.Mažeika, A.Gusarov, M.Schyns, M.Dierckx, H.Ait Abderrahim. Acoustic computer model for ultrasonic imaging of heavy liquid metal nuclear reactor. 2010 IEEE International Conference on Imaging Systems and Techniques, July 1-2. 2010. Thessaloniki, Greece: proceedings. Piscataway : IEEE, 2010. ISBN 9781424464937. p. 244-247.
- E.Jasiūnienė. Ultrasonic imaging techniques for non-destructive testing of nuclear reactors, cooled by liquid metals: review. Ultragarsas = Ultrasound. Kauno technologijos universitetas. Kaunas: Technologija. ISSN 1392-2114. 2007. T. 62. Nr. 3. p. 39-43. /pdf/
- E.Jasiūnienė, R.Šliteris, L.Mažeika, R.Kažys. Verification of the acoustic computer model for the case of two tilted planar reflectors. Ultragarsas = Ultrasound. Kauno technologijos universitetas. Kaunas: Technologija. ISSN 1392-2114. 2008. T. 63. Nr. 4. p. 41-45. /pdf/
- R.Kažys, L.Mažeika, E.Jasiūnienė, R.Šliteris, P.Kupshus, R.Van Nieuwenhove, H.Ait Abderrahim. Ultrasonic imaging techniques for the visualisation in hot metals. Proceedings of the World Congress on Ultrasonics: September 7-10. 2003. Paris, France. Paris, 2003. ISBN 2952110506. p. 1391-1394. [0,143].
- R.Kažys, L.Mažeika, A.Voleišis, R.Šliteris, E.Jasiūnienė, H.Ait Abderrahim, M.Dierckx. Ultrasonic imaging in the liquid metals // ISEM 2005: 12th international symposium on Interdisciplinary Electromagnetic, Mechanic and Biomedical Problems, 12-14 Sept. 2005, Bad Gastein, Austria : short paper proceedings. Vienna: Vienna Magnetic Group Reports, 2005. ISBN 3902105001. p. 164-165. [0,143].
- R.Kažys, L.Mažeika, E.Jasiūnienė, A.Voleišis, R.Šliteris, H.Ait Abderrahim, M.Dierckx. Ultrasonic evaluation of status of nuclear reactors cooled by liquid metal // 9th European Conference on NDT: Setember 25-29, 2006, Berlin / German Society for Non-Destructive Testing (DGZIP), European Federation for Non-Destructive Testing (EFNDT). Berlin: DGZfP, 2006. (DGZfP Proceedings, Vol. 103-CD). ISBN 3931381862. p. [1-8]. [0,143].
- L.Mažeika, E.Jasiūnienė, R.Kažys, R.Šliteris, R.Raišutis, H.Ait Abderrahim, M.Dierckx. 3D acoustic model of a nuclear reactor cooled by liquis metal alloy for investigation of ultrasonic imaging systems // ICU 2007: proceedings of the international congress on ultrasonics, April 9-13, 2007, Vienna, Austria. Vienna: Institut für Allgemeine Physik, 2007, paper ID 1374. p. [1-4]. [0,143].
- R.Kažys, A.Voleišis, R.Šliteris, L.Mažeika, R.Van Nieuwenhove, P.Kupschus, H.Ait Abderrahim. High temperature ultrasonic transducers for imaging and measurements in a liquid Pb/Bi eutectic alloy. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. ISSN 0885-3010. Vol. 52. No. 4. 2005. p. 525-537. /pdf/
- R.Kažys, A.Voleišis, R.Šliteris, B.Voleišienė, H.Ait Abderrahim, P.Kupschus. Development of ultrasonic transducers for ranging and imaging in a heavy liquid metal. Proceedings of the IEEE Sensors 2004: October 24-27, 2004, Vienna University of Technology, Vienna, Austria. New York: IEEE, 2004. ISBN 0-7803-8692-2. p. 646-469. /pdf/
- R.Kažys, A.Voleišis, R.Šliteris, B.Voleišienė, L.Mažeika, P.Kupschus, H.Ait Abderrahim. Development of ultrasonic sensors for operation in a heavy liquid metal. IEEE Sensors Journal. ISSN 1530-437X. Piscataway: IEEE. 2006. Vol. 6. No. 5. p. 1134-1143. /pdf/
- R.Kažys, A.Voleišis, L.Mažeika, R.Šliteris, R.Van Nieuwenhove, P.Kupschus, H.Ait Abderrahim. Investigation of ultrasonic properties of a liquid metal used as a coolant in accelerator driven reactors. Proceedings of the 2002 IEEE International Ultrasonics Symposium, Miunich, Germany. October 8-11, 2002. p. 794-797. /pdf/
- R.Kažys, A.Voleišis, R.Šliteris, L.Mažeika, R.Van Nieuwenhove, P.Kupschus, H.Ait Abderrahim. Ultrasonic transducers for high temperature application in accelerator driven reactors. Proceedings of WCU, Paris, September 7-10, 2003. p. 33-36.