Investigation of specific applications of laser cutting for dismantling of nuclear power plants

European Commission Directorate-General For The Information Society And Media Directorate-General For Research And Innovation

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Nuclear energy and safety
Energy research

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• Publié par: EUROPEAN-COMMISSION-DIRECTORATE-GENERAL-FOR-THE-INFORMATION-SOCIETY-AND-MEDIA-DI
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

Commission of the European Communities
Investigation of specific applications
of laser cutting for dismantling
of nuclear power plants Commission of the European Communities
nuclear science
and technology
Investigation of specific applications
of laser cutting for dismantling
of nuclear power plants
B. Migliorati,1 G. Tarroni,2 M. DiFino,3
Ρ Picini,4 G. Manassero,5
1 Fiat-CIEI 3 ENEA-TIB-FIS-TECNLAS
Via Cuneo 20 Via E. Fermi 27
1-10152 Torino I-00044 Frascati-Roma
2ENEA-PAS-FIBI-Aerosol 4ENEA-PAS-ISP-AMB
V.leG.B. Ercolani 8 CP 2400
1-00100 Roma 1-40138 Bologna
5 Fiat-CRF
Strada Torino 50
1-10043 Orbassano-Torino
This work was performed in the framework of the European Communities
research programme on decommissioning of nuclear installations
Project No 3 'Dismantling techniques'
Contract No FI1D-0014-I
Directorate-General
Science, Research and Development
1990 EUR 12947 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Telecommunications, Information Industries and Innovation
L-2920 Luxembourg
LEGAL NOTICE
Neither the Commission of the European Communities nor any person
acting on behalf of the Commission is responsible for the use which might
be made of the following information
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1990
ISBN 92-826-1687-8 Catalogue number: CD-NA-12947-EN-C
© ECSC-EEC-EAEC, Brussels · Luxembourg, 1990
Printed in Luxembourg CONTENTS
Page
1 GENERAL INTRODUCTION
PART I: AEROSOL CHARACTERIZATION IN STEEL CUTTING BY MEANS OF
LASER BEAM 3
3 1.1 INTRODUCTION
4 1.2 MATERIALS AND METHODS
4 1.2.1 Experimental Facility
1.2.2 Instrumentation for Aerosol Measurements 5
1.2.3 Sampling Arrangement 6
1.2.4 Reliability of the Aerosol Measurements 9
1.3 EXPERIMENTAL RESULTS 13
1.3.1 Particle Morphology and Granulometry 13
1.3.2 Aerosol Production and Slag 26
1.3.3l Elemental Composition 35
1.3.4 Effect of Local Aspiration on the Aerosol Concentration in
the Cutting Box and on the Measurement of Effluents 42
1.3.5 Comparative Cutting Tests 51
1.4 CONCLUSIONS 53
REFERENCES 54
PART II: BEHAVIOUR OF HEPA FILTERS LOADED BY AEROSOLS ARISING
FROM HIGH TEMPERATURE METAL CUTTING PROCESS 55
II. 1 INTRODUCTION 55
Π.2 MATERIALS AND METHODS 55
11.2.1 Plasma Torch 56
11.2.2 Remote Handling 56
11.2.3 Cutting Box 57
11.2.4 Ventilation Channel and Filtration Bank 57
11.2.5 Experimental Devices and Methods 62
11.3 TESTS AND EXPERIMENTAL RESULTS 63
11.3.1 First Set 63
11.3.2 Second Set 70
11.3.3 Third Set 76
11.4 CONCLUSIONS 83
APPENDIX 84
III PART III: LASER BEAM PROPAGATION AND CONTROL 95
ΙΉ.1 INTRODUCTION 9
111.2 LASER BEAM PROPAGATION
111.3 LASER BEAM TRANSMISSION AND REMOTE FOCALIZATION 97
111.4 LASER ROBOT FOR DISMANTLING THE GARIGLIANO "STEAM
DRUM" 101
111.4.1 S tudy of the Optical S ystem
111.4.2 Laser System for Laboratory Cutting Tests 106
111.4.3 Cutting Tests 11
ΠΙ.5 CONCLUSIONS3
REFERENCES
PART IV: STUDY OF THE APPLICATION OF THE LASER BEAM TECHNIQUE
TO DISMANTLING OF A SPECIFIC NUCLEAR COMPONENT 115
IV. 1 INTRODUCnON 11
IV.2 DESCRIPTION OF THE GARIGLIANO STEAM DRUM
IV.3 EQUIPMENT REQUIRED FOR THE DISMANTLING OPERATIONS 118
IV.3.1 Equipment Installed Outside the Work Room 11
IV.3.1.1 Laser equipment8
IV.3.1.2 Hoisting and Transfer Devices
IV.3.2 Equipment Installed Inside the Work Room
IV.3.2.1 Laser Robot for Cutting and Removal of the Inner Parts 11
IV.3.2.2 Equipment for Dismantling the Steam Drum Shell 122
IV.3.2.3 Ventilation Systems 123
IV.3.2.4 Auxiliary Devices4
IV.4 DISMANTLING PROCEDURES
IV.4.1 Preliminary Activities
IV.4.2 Area Preparation8
IV.4.3 Actual Dismantling
IV.5 CONCLUSIONS 129
GENERAL CONCLUSIONS 131
IV GENERAL INTRODUCTION
The general aim of the work carried out in the frame of the contract No FI1D-0014-I
signed in 1985 between CEC and FIAT-TTG (main contractor) / ENEA, was to obtain a more
complete evaluation of the possibility of using the laser beam cutting technique in dismantling
nuclear power plants.
The specific aims of the research were:
- obtaining a better knowledge of the aerosols produced and investigating the possibilities of
their abatement and filtration;
- studying systems for transmission of the laser beam over long distances to give more
concrete motivations for the possible use of this cutting technique as a dismantling method;
- studying the possibility of practical utilization of laser beam cutting for dismantling a real
complex system.
To obtain these goals, the activities were subdivided from the beginning between
laboratories belonging both to private industry (FIAT) and to the public administration (ENEA).
The groups involved were:
- Laboratory of Aerosol Physics and Toxicology, Department of Environmental
Protection and Human Health (ENEA-PAS-FIBI-AEROSOL, situated in Bologna),
which performed all the measurements (sampling, analysis and data treatment)
relative to aerosol and slag produced in laser beam cutting;
- Laboratory of Laser Technology, Department of Basic Intersectorial Technology
(ENEA-TIB-FIS-TECNLAS, situated in Frascati, near Rome), which was mainly
involved in the set-up of the 2kW power cutting facility and the exhausting line;
- Laboratory of Experimental Engineering, Department of Environmental Protection
and Human Health (ENEA-PAS-ISP-AMB, situated in Casaccia, near Rome), with
the task of studying the behaviour of HEPA filters challenging the aerosols produced
during high temperature cuttings;
- FIAT-CRF (Turin), which studied the most efficient methods for transmitting laser beam
power over long distances;
- FIAT-CIEI (Turin), with the task of studying a conception for the dismantling of a
specific component of the Garigliano nuclear power plant by taking into account the results
obtained in the course of the programmed experiences.
To ensure coherent progress of the experimental work, the activity for each period was
defined in meetings with all groups involved in order to assess the results obtained with respect
to contractual planning.
The present, final report takes into account organization of the work, as previously
mentioned and is consequently subdivided into four pans: aerosol characterization (Part I), behaviour of HEPA filters (Part II), transmission of the laser beam over long distances
(Part III) and study of a practical application (Part IV). Each part of the report has been
prepared by the contributors concerned. PART I
AEROSOL CHARACTERIZATION IN STEEL CUTTING BY MEANS
OF LASER BEAM
G. Tarroni*, M. Di Fino**, T. De Zaiacomo*, C. Melandri*,
M. Formignani*, L. Barilli*
* ENEA-PAS- FIBI- AEROSOL, V.le Ercolani 8,1-40138 Bologna (Italy)
** ENEA-TIB-FIS-TECNLAS, Via E. Fermi 27, 1-00044 Frascati-Roma (Italy)
1.1 INTRODUCTION
The activity concerning the characterization of aerosol and slag produced in cutting steel
by means of a laser beam was carried out in strict collaboration between two ENEA groups:
- Laboratory of Aerosol Physics and Toxicology, Department of Environmental Protection
and Human Health (PAS-FIBI-AEROSOL, situated in Bologna);
- Laboratory of Laser Technology, Department of Basic Intersectorial Technology (TIB-FIS-
TECNLAS, situated in Frascati, near Rome).
The TIB-FIS-TECNLAS Laboratory was mainly involved in the set-up of the cutting
facility and exhausting line. The PAS-FIBI-AEROSOL Laboratory performed all the aerosol
and slag measurements (sampling, analysis and data treatment).
Because of the need to move people and instruments for each test, the activity was
organized in such a way that experimental campaigns were executed at the TIB-FIS-TECNLAS
Laboratory in Frascati, with well-defined purposes and a precise subdivision of the tasks;
integration of competences was made in order to obtain the best possible results.
The specific objectives of each campaign were defined in meetings with the groups
involved respectively in: filtration techniques (PAS-ISP-AMB, Casaccia, Rome), transmission
of the laser beam over long distances (FIAT-CRF, Turin), engineering of the system (FIAT-
CIEI, Turin). Examination of the results was conducted with the same aim of integration.
In the first series of tests, one of the main objectives was to validate both the experimental
facility and the aerosol sampling and analysis systems for the type of tests and type of particles
under study. In the course of the programmed experiences, some modifications were
consequently performed both in the facility and the operative procedures. As an example, the
exhaust duct was initially made of flexible corrugated hose (15 cm I.D.), in which the
transversal velocity profile was not sufficiently defined, and the relative data of the flowrate
values were rather variable. The flexible hose was therefore substituted by a rigid duct of the
same internal diameter.thus obtaining better reliability and reproducibility for the aspiration
-3 flow data.
This report is concerned by data relat