THE PRESENT RESEARCH WORK IS A FOLLOW-UP OF WORK PERFORMED IN THE 1979-83 RESEARCH PROGRAMME, WHERE IT WAS DEMONSTRATED THAT LASER BEAM CUTTING HAS A POTENTIAL FOR A USEFUL APPLICATION TO DECOMMISSIONING, DUE TO THE VERY REDUCED QUANTITY OF GENERATED AEROSOLS AND TO ITS POSSIBILITY FOR REMOTE OPERATION (REF. : EUR 9715).
THE MAIN OBJECTIVES OF THE PRESENT CONTRACT ARE AS FOLLOWS : EXECUTION OF OPERATIONAL CUTTING TESTS WHICH 7-10 KW LASERS ON REPRESENTATIVE MATERIALS OF THE GARIGLIANO BWR, WITH A VIEW TO DETERMINING QUANTITIES AND DISTRIBUTIONS OF THE GENERATED AEROSOL PARTICLES, EXECUTION OF FEASIBILITY STUDIES FOLLOWED BY PRACTICAL APPLICATIONS USING MOCK-UP COMPONENTS. THE STUDY WILL BE COMPLETED WITH THE ASSESSMENT OF THE POSSIBILITY OF USING LASER CUTTING OF SPECIFIC COMPONENTS, CONSIDERING THE FUTURE DECOMMISSIONING OF THE GARIGLIANO BWR.
The general examination of all the data concerning the aerosol produced in cutting steel by means of laser beam allow us to draw some general conclusions. The aerosol produced in cutting steel by the high temperature technique based on the use of laser beam shows two spectral modes, corresponding to well defined particle structures. A first mode composed of aggregates of very fine particles and a second mode composed of spherical and compact particles of diameter greater than a few micrometres. The aerodynamic and diffusive granulometric characteristics of the first mode was a function of: the concentration at the source (generation rate), the aerosol life time and the concentration at which it is maintained. In fact the main phenomenon involved in the granulometric modification for this type of particle is coagulation. In the end the efficacy of a local aspiration system was tested, at laboratory scale, to reduce the aerosol dispersion in the ambient where the cutting took place, by avoiding contamination of other surfaces.
B.1. CHARACTERISATION OF AEROSOL ARISINGS FROM LASER CUTTING.
B.1.1. EXECUTION OF CUTTING TESTS ON MATERIALS REPRESENTATIVE OF GARIGLIANO BWR COMPONENTS, SUCH AS STAINLESS STEEL, CARBON STEEL AND CONCRETE.
B.1.2. DETERMINATION OF AEROSOL QUANTITIES AND DISTRIBUTIONS, WITH SPECIAL ATTENTION TO SMALL PARTICLES (DIAMETER < 0,5 MICRON).
B.2. ASSESSMENT OF THE APPLICABILITY OF REMOTE OPERATION LASER CUTTING OF SPECIFIC GARIGLIANO BWR COMPONENTS.
B.2.1. EXECUTION OF FEASIBILITY STUDIES FOR REMOTE LASER-CUTTING.
B.2.2. QUALIFICATION TESTS ON REAL-SIZE MOCK-UP COMPONENTS OF THE GARIGLIANO BWR.
Funding SchemeCSC - Cost-sharing contracts