ISSN 1018-5593 European Commission ¡-'- SÌ The Community's research and development programme on decommissioning of nuclear installations (1989-93) Annual progress report 1993 M »»* *\ European Commission II??:! The Community's research and development programme on decommissioning of nuclear installations (1989-93) Annual progress report 1993 ULSei Directorate-General Science, Research and Development PARI. MRCP, fctíWh, *M» 1994 N.C.EUR 15854 EN 01, \ Published by the EUROPEAN COMMISSION Directorate-General XIII Telecommunications, Information Market and Exploitation of Research L-2920 Luxembourg LEGAL NOTICE Neither the European Commission 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, 1994 ISBN 92-826-8401-6 © ECSC-EC-EAEC, Brussels · Luxembourg, 1994 Printed in Spain ABSTRACT This is the fourth annual progress report of the European Community's programme (1989-93) of research on decommissioning of nuclear installations. It shows the status of the programme on 31 December 1993. This fourth progress report summarizes the objectives, scope and work programme of the 79 research contracts concluded, as well as the progress of work achieved and the results obtained in 1993. FOREWORD The following fourth Annual Progress Report summarises the activities of the European Communities R&D Programme on Decommissioning of Nuclear Installations for the year 1993. (Annual progress reports 1990, 1991 and 1992, see ref. /I/, 111 and ßl). This programme was adopted by the EC Council in March 1989 14/ to find "effective solutions which are capable of ensuring the safety and protection of both mankind and its environment against the potential hazards in decommissioning".. As a large number of older nuclear facilities will be taken out of service in the next ten years, the public, the industry and national regulations are becoming increasingly Concerned about the occupational doses, environmental hazards and the costs which could be incurred in the decommissioning of such plants. The European Community, well aware of these concerns, has since 1978 operated and financed research programmes in this field. The 1989-1993 programme concerns the following areas: A. Research and development projects concerning the following subjects: Area N° 1: Long-term integrity of building and systems; Area N° 2: Decontamination for decommissioning purposes; Area N° 3: Dismantling techniques; Area N° 4: Treatment of specific waste materials: steel, concrete and graphite; Area N° 5: Qualification and adaptation of remote-controlled semi-autonomous manipulator systems; Area N° 6: Estimation of the quantities of radioactive wastes arising from the decommissioning of nuclear installations in the Community. B. Identification of guiding principles relating to: the design and operation of nuclear installations with a view to simplifying their subsequent decommissioning, the decommissioning operations with a view to making occupational radiation exposure as low as reasonably achievable, the technical elements of a Community policy in this field. C Testing of new techniques in practice: pilot projects, alternative tests, staff secondment. The research is carried out by public organisations and private firms in the Community under cost- sharing contracts with the Commission of the European Communities. The Programme's budget for the five-year period 1989-1993 amounted to 33.8 million ECU. In 1993, further funds (5.8 million ECU) were made available to permit continuation of the most important projects during 1994 and 1995. Work on the four pilot dismantling projects will therefore continue. Also during 1993, Part B "Identification of guiding principles" was completed and the report is due to be published in 1994. V- The common action to collect data relevant to cost, occupational doses, working time and waste arisings is now a fully operational part of the programme. I am most grateful to the contractors who have produced most of the substance of this report and who provided a particular effort to make its timely publication possible. For its compilation and editing I wish to thank my colleagues, Messrs R Bisci, Κ Pflugrad and R Wampach. This is probably the last annual report of the third EU Decommissioning Programme (1989-1993). In 1994, the annual report will be replaced by the Proceedings of the Third International Conference on the Decommissioning of Nuclear Installations (26-30 September 1994, Luxembourg), which will present the final state of the programme's activities. R SIMON Head of the Programme References HI "The Community's research and development programme on decommissioning of nuclear installations (1989-1993)". Annual progress report 1990. EUR 14227. HI "The Community's research and development programme on decommissioning of nuclear installations (1989-1993)". Annual progress report 1991. EUR 14498. 13/ "The Community's research and development programme on decommissioning of nuclear installations (1989-1993)". Annual progress report 1992. EUR 15262. /4/ Council Decision of 14 March 1989 adopting a research and technological development programme for the European Atomic Energy Community in the field of the decommissioning of nuclear installations. OJ No. L 98, 11.04.1989, p. 33. 151 Commission Communication concerning the research programme on the decommissioning of nuclear installations (1989 to 1993). Call for research proposals. OJ No. C 24, 31.01.1991, p. 8. VI CONTENTS SECTION A: RESEARCH AND DEVELOPMENT PROJECTS Page 1. AREA No. 1: LONG-TERM INTEGRITY OF BUILDINGS AND SYSTEMS 1 1.1. Examination and long-term assessment of nuclear power structures 2 2. AREA No. 2: DECONTAMINATION FOR DECOMMISSIONING PURPOSES 9 2.1. On-line decontamination of complex components for unrestricted release, using ultrasonic waves in a flowing aggressive chemical agent 10 2.2. Development and optimisation of an easy-to-process electrolyte for electrochemical decontamination of stainless steel 17 2.3. Microwave system to scarify concrete surfaces 18 2.4. Decontamination of large-volume nuclear components using foams 24 2.5. Decontamination of an evaporator of a pilot reprocessing plant (EUREX- Saluggia) using a chemical agent dispersed as fog 30 2.6. Decontamination technique using a dispersed chemical agent 36 3. AREA No. 3: DISMANTLING TECHNIQUES 39 3.1. Effectiveness and long-term behaviour of cleanable high efficiency aerosol filters 40 3.2. Abrasive water jet cutting technique from the stage of laboratory into real application 41 3.3. Steel cutting using linear-shaped charges 42 3.4. Evaluation of the segmentation by various cutting techniques (plasma torch, arc saw, circular disc, etc) 47 3.5. Underwater thermal cutting techniques and associated remote-controlled manipulator systems 52 3.6. Development of a plasma arc torch and control/monitoring technique for the internal cutting of small bore pipework 59 3.7. Development of a steel cable to cut highly reinforced concrete with minimised water consumption 62 3.8. Assessment of state-of-the-art CO laser technology as an improved dismantling tool 63 3.9. Cutting of C02 primary circuit pipes of G2/G3 reactors using explosive charges 64 3.10. Underwater laser cutting of metal structures 70 3.11. Optimisation of plasma torch electrode design for nuclear dismantling tasks 76 VII 4. AREA No. 4: TREATMENT OF SPECIFIC WASTE MATERIALS: STEEL,'CONCRETE AND GRAPHITE 79 4.1. Industrial­scale melting of tritium­containing steel from nuclear installations 80 4.2. Development of a process for volume reduction of contaminated/activated concrete waste including pilot­scale testing with active waste 81 4.3. Treatment and conditioning of radioactive graphite from nuclear installations 88 • •»•••■••••••Φ···············**···"··""" 4.4. Recycling of activated/contaminated reinforcement metal in concrete .... 94 4.5: Investigations on recycling of radioactive non­ferrous aluminium and copper by melting process 95 5. AREA No. 5: QUALIFICATION AND ADAPTATION OF REMOTE­ CONTROLLED SEMI­AUTONOMOUS MANIPULATOR SYSTEMS 101 5.1. Robotic system for dismantling of the process cell of a reprocessing plant. 102 5.2. Design, construction and testing of a manipulator for removing slag, measuring temperature and taking samples during melting of radioactive metal 109 5.3. Telerobotic monitoring, decontamination and size reduction system ­ TMDSRS 116 5.4. Adaptation and testing of a remotely­controlled underwater vehicle 123 5.5. Test of long­range teleoperated handling equipment with different tools for concrete dismantling and radiation protection monitoring 126 5.6. Underwater qualification of RD 500 manipulator 128 6. AREA No. 6: ESTIMATION OF THE QUANTITIES OF RADIOACTIVE WASTE ARISING FROM DECOMMISSIONING OF NUCLEAR INSTALLATIONS IN THE COMMUNITY 135 6.1. Methodology to evaluate the risks of decommissioning operations on nuclear plants 136 6.2. Doses due to the reuse of very slightly radioactive steel 137 6.3. Quick measuring methods of radionuclides in materials and wastes during decommissioning of nuclear installations 146 6.4. Radiological aspects of recycling concrete debris from dismantling of nuclear installations 152 6.5. Definition of reference levels for exemption of concrete coming from dismantling 155 6.6. The characterisation and determination of radioactive waste from decommissioning 156 ■VIII 6.7. Quantification of activity