O.E.C. D. RA HIGH TEMPERATURE REACTOR PROJECT TV ORGANISATION FOR ECONOMIC COOPERATION AND DEVELOPMENT NUCLEAR ENERGY AGENCY O.E.C.D. HIGH TEMPERATURE REACTOR PROJECT ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT NUCLEAR ENERGY AGENCY The Organisation for Economic Co-operation and Devel• opment (OEGD) was set up under a Convention signed in Paris on 14th December, 1960, which provides that the OECD shall pro• mote policies designed: — to achieve the highest sustainable economic growth and employment and a rising standard of living in Member countries, while maintaining financial stability, and thus to contribute to the development of the world economy; — to contribute to sound economic expansion in Member as well as non-member countries in the process of economic development; •— to contribute to the expansion of world trade on a multi• lateral, non-discriminatory basis in accordance with inter• national obligations. The Members of OECD are Australia, Austria, Belgium, Cana• da, Denmark, Finland, .France, the Federal Republic of Germany, Greece, Iceland, Ireland, Italy, Japan, Luxembourg, the Nether• lands, N'ew Zealand, Norway, Portugal, Spain, Sweden, Switzer• land, Turkey, the United Kingdom and the United States. The OECD Nuclear Energy Agency (NEA) was established on L'olh April i[)/L>. replacing OECD's European Nuclear Energy Agency (ENEA) on the adhesion of Japan as a full Member. NEA now groups all the European Member countries of OECD and Australia, Canada, Japan, and the United States. The Commission of the European Communities takes part in the work of the Agency. The objectives of NEA remain substantially those of ENEA , namely the orderly development of the uses of nuclear energy for peaceful pui poses. This is achieved by: — assessing the future role nf nuclear energy as a contributor to eco• nomic progress, and encouraging co-operation between governments towards its optimum development ; — encouraging harmonisation of governments' regulatory policies and practices in the nuclear field, with particular reference lo health and safely, radioactivi waste management and nuclear third party liability and insurance ; — forecasts of uranium resources, production and demand: — operation of common services and encouragement of co-operation in the field of nuclear energy information ; — sponsorship of research and development undertakings jointly orga• nised and operated by OECD countries. In these tasks NEA works in close collaboration with the International Atomic Energy Agency, with which it has concluded a Co-operation Agree• ment, as well as with other international organisations in the nuclear field. © OECD, 1977 Queries concerning permissions or translation rights should be addressed to: Director of Information, OECD 2, rue Andre-Pascal, 75775 PARIS CEDEX 16, France. 2 OECD HIGH TEMPERATURE REACTOR PROTECT DRAGON SEVENTEENTH ANNUAL REPORT 1 April 1975 - 31 March 1976 ******** List of Contents ******** FOREWORD 7 Frontispiece 8 INTRODUCTION 9 PART I - DRAGON REACTOR EXPERIMENT 13 THE IRRADIATION PROGRAMME 15 Operation of Charge V, Cores 6 and 7 15 Termination Work 15 SUPPORT FOR THE DRAGON REACTOR EXPERIMENT 16 Design 16 Physics 17 Thermal and Stress Analysis of Experiments 17 Fuel Element Manufacture 18 Fuel Recovery 18 POST-IRRADIATION OPERATIONS 18 Programme 18 Some Experimental Findings 20 PART II - RESEARCH AND DEVELOPMENT AND ADVANCED APPLICATIONS 25 FUEL AND GRAPHITE 27 Kernel Studies 27 Coating Studies 28 Coating Studies - Pyrocarbon Structure 29 Consolidation Studies 31 Quality Control 32 3 Extra-Mural Irradiation Experiments 32 Experiments in the Dragon Reactor Experiment 32 Development of Carbon-Based Carbon Fibre Composites 33 Irradiation Performance of Graph'ite for HTRs 33 PRIMARY CIRCUIT MATERIALS 36 Test Programme at CIIR Oslo 36 Test Programme at Central Research Laboratories FIAT 39 Experiments in Dragon Reactor Fuel Elements 40 Experiments in Heat Exchanger By-Pass Ducts of the Dragon Reactor Experiment 41 Reactor Experiment Components 41 Very High Temperature Experiment • 42 POWER REACTOR PHYSICS, ADVANCED APPLICATIONS AND KINETICS 42 Fuel Cycle Studies 42 Evaluation of Physics Experiments 42 Preliminary Studies for a VHTR 42 Kinetics Model Studies for Advanced Systems 43 HTR TECHNOLOGY 44 Fission Product Studies 44 Graphite Corrosion and Permeation Studies 44 Experiments in the Dragon Reactor Experiment 45 Friction and Wear Tests 45 Safety Studies 45 In-Core Instrumentation 45 PART III - ADMINISTRATION 49 APPENDICES I Personnel In Post on 31 March 1976 53 II Senior Staff Structure at 31 March 1976 55 III Board of Management 57 IV General Purposes Committee 59 V Dragon Project 1975/76: Inter-relation of Budgets and Further Extension Negotiations 61 VI Expenditure Estimates 65 VII Commitments Estimate 67 VIII Publications 1975/76 69 IX List of Filed Dragon Project Patent Specifications 71 4 * * * * * * * * List of Figures ******** Frontispiece The Dragon Reactor Experiment 1 Bottom Face of Top Fuel Block MHGB 2A 21 2 Block Experiment Irradiated in Dragon 240 Days after Destructive Post-Irradiation Examination 22 3 HOBEG Moulded Graphite Block 23 4 A Typical Example of the Relationship Between Particle Damage Due to Irradiation and the Deposition Rate of the Pyrocarbon Coating 28 5 Agglomerate Diameter (measured üTyUm) 30 6 Typical Pyrocarbon Deposit on Plate 30 7 Dimensional Changes of Pressed Petroleum Coke Graphite (Axial Direction) 34 8 Systematised Dimensional Changes of Pressed Petroleum Coke Graphite (Axial Direction) 35 9 Surface Oxide Depth vs Temperature for Various Alloys After 5000 Hours in HTR Helium 37 10 Weight Gain of Cast High Nickel Alloys at 900°C .. 38 11 Creep Curves of INCONEL 625 in Helium and Air at 85 0°C 38 12 Fuel Rod End Plug Containing Metal & Ceramic Specimens 40 13 Specimens of Tungsten Molybdenum and TZM Exposed in the By-Pass Duct for 3000 Hours 41 •kick kkkkk 5 FOREWORD This Seventeenth and last Annual Report of the OECD High Temperature Reactor Project (DRAGON) is submitted to the Steering Committee of the Nuclear Energy Agency (NEA) in accordance with the terms of the Dragon Agreement. The participants in the Project have been The Austrian Government, The Commission of the European Communities, A B Atom• energi of Sweden, The Swiss Government, The Norwegian Institute for Atomenergi (1959/73) and The United Kingdom Atomic Energy Authority. The period from 1 April 1975 to 31 March 1976, covered by the present report, marked the third year of the* fifth extension of the Dragon Project. The Project was terminated on 31 March 1976. 7 Frontispiece - THE DRAGON REACTOR EXPERIMENT INTRODUCTION After 17 years of successful activity by the DRAGON Project the Agreement of the Signatories to the OECD High Temperature Reactor Project (DRAGON) expired on 31 March 1976. The Agreement required that a decision regarding its further extension should be made by 30 June 19 75, and in April the Dragon Board of Management proposed a further five year extension to the Signatories. However, despite prolonged discussions the major Signatories were unable to reach agreement on the terms for a further extension even of shorter duration, and in December, when there was no further possibility of preserving the Project's viability, the Board of Management had to give termination instructions. The need to maintain as effective a programme as possible pending the decision on a further extension, coupled with the impact of inflation and exchange losses on the Project's finances, meant that by December the available funds allowed only for the retention of a skeleton staff for essential winding up activities. These included the dis• charge and dismantling of all fuel elements from the Dragon Reactor Experiment (DRE) and the storage of the irradiated fuel, leaving the reactor in a completely safe condition. In these circumstances in order to ensure that valuable information from the DRE experiments should not be lost, Kernforschungsanlage, Jülich (KFA) took a generous decision to fund a data retrieval programme, the results of which would be made available to all the Signatories. This enabled specimens from irradiated experiments to be retrieved from the DRE during the dismantling of the fuel elements and transported to Jülich for detailed post- irradiation examination. It should be recorded that specimens from experiments sponsored by others including the UKAEA, the Commissariat a l'Energie Atomique and Belgonucleaire were also returned to their sponsors. In all instances the sponsors agreed to carry out the post-irradiation examination at their own expense, and eventually to report the results to the Dragon Signatories in accordance with the original conditions under which the Dragon irradiation experiments were undertaken. An important function of the KFA funding was to provide for the continued sponsorship of the Dragon primary circuit materials programme, The United States Energy Research & Development Administration also became a partner to an arrangement under which this work was enabled to continue and some additional money was provided from the EEC Joint Research Centre at Petten, Holland. After 31 March 1976 the team directing this work became the High Temperature Materials Programme, with continuing KFA/ERDA sponsor• ship, on the premises of Flight Refuelling Limited, Wimborne, Dorset (near the Dragon Site at AEE, Winfrith). In the continuing programme of work the outcome of experiments started under Dragon Project auspices will be reported to the Signatories. The KFA and other support made it possible to recover an important part of the data accumulated in the Dragon programme. An attempt was made at the beginning of 1976 to secure a more comprehensive data retrieval programme which would have continued through 1976 with the financial back• ing of most of the Signatories. Unfortunately, although the small Signatories gave their support to this idea, it proved impossible to reach a decision before termination of the Project on 31 March 1976. Upon the termination of the Dragon Agreement and in accordance with its terms, the fixed assets of the Project, notably the DRAGON REACTOR EXPERIMENT itself, came into the ownership of the host Signatory, the UKAEA.