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1.

Experimental investigation of the acceleration of deflagration in wake flow : final report. European Commission. DG XII – Science, Research and Development.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1983.

Summary

The topic of the project was the experimental investigation of the flame acceleration mechanism of the deflagrative combustion of partially confined hydrocarbon-air gas clouds in conditions of turbulence- producing geometry. The main point of the investigation was the study of the interaction between the flow field and the reaction zone and its influence on pressure build-up. An important characteristic of the experiments described in this réport is that the flow field has been produced by hydrodynamical means and not only by the expanding reaction products. Using a suitable experimental set up, it was possible to vary the flow velocity present at the moment of ignition in a wide range. The influence of an initial flow field must be taken into account in connection with safety aspects of nunclear power platns or sites for chemical engineering, since in real gas cloud explosion such flow fields, which may have its origin in atmospheric wind, interaction with buildings, venting of buildings, etc. are usually present. Particularly, in the turbulent wake of structures, the flame surface can be folded and that may lead to an increasing burning rate and again to an increasing level of overpressure. In gas cloud explosions, turbulence is produced by the flow-field induced by the combustion process. But turbulence can also be produced by an initial flow field, due to atmospheric wind or technical devices. This turbulence may lead to an increased rate of chemical reaction, inducing high pressure levels. The reported laboratory-scale experiments were designed to investigate the influence of a flow field, present at the moment of ignition inside a partially-confined hydrocarbon-air cloud. These experiments used a flow channel capable of producing an unsteady flow-field of combustible gas independently of the combustion process itself. The parameters which varied in these tests are: initial flow velocity, gas-mixture composition and geometry. The tests were carried out with stochiometric ethylene-air and propane-air mixtures. The measured quantities are: pressure time history inside the test section, CH-radical radiation. High-speed photographs were also taken. The results show that initial flow speed and reactivity of the mixture have a strong influence on the maximum overpressure and duration of the positive pressure phase, but quenching effects may become important for high flow velocities and mixtures of low reactivity.

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2.

Plasma arc and thermal lance techniques for cutting concrete and steel. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1986-05-21.

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3.

Heat transfer experiment in a granite formation at Cornwall. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-07-17

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4.

Treatment of active concrete waste arising from the dismantling of nuclear facilities. DG XIII – Information Market and Innovation.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-03-11.

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5.

Comparison of European computer codes relative to the aerosol behaviour in PWR containment buildings during severe core damage accidents. Commission of the European Communities. DG XII – Science, Research and Development.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1987.

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6.

Management modes for iodine-129. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1984-12-28.

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7.

Corrosion behaviour of container materials for geological disposal of high-level waste : Annual progress report 1984. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1986-05-30.

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8.

A study of explosive demolition techniques for heavy reinforced and prestressed concrete structures. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-07-23.

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9.

Aspects of the dispersion of denser-than-air vapours relevant to gas cloud explosions : final report. European Commission. DG XII – Science, Research and Development.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1984.

Summary

Models for dispersion in the atmosphere of denser-than-air vapours have been reviewed. It has been found that a significant source of uncertainty in the predictions of all models is the calculation of dilution caused by turbulence. This is due to spreading and stratification caused by the excess density of the cloud and to the interaction of the cloud motion with the ambient flow field. These effects lead to a complex field of turbulence. An additional, significant source of uncertainty is present in '3D' models due to the use of coarse computational grids. A number of experimental tests have been proposed which will enable fundamental discrimination between the models with the object of reducing uncertainties. A new 'box' model has been proposed (a 'box' model is one in which only gross properties of the flow are predicted). All sources of turbulence are included in a way consistent with laboratory studies of entrainment in stratified flows. The prescribed concentration distribution permits the description of the initial 'mixed layer/gravity spreading' phase and the final 'passive' phase of dispersion with a smooth transition between the two. Implications of dispersion of denser-than-air flammable vapour clouds in open terrain on flame speeds following ignition by a weak source have been assessed. It is concluded that flame speeds sufficient to cause significant overpressures cannot occur.

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10.

Washing processes for plutonium recovery from solid wastes. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1987-01-05.

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11.

Experimental investigation of the acceleration of deflagration in wake flow. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1984-12-19.

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12.

Corrosion behaviour of container materials for geological disposal of high level radioactive waste. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-08-05.

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13.

Review of specific effects in atmospheric dispersion calculations : The impact of source-term characteristics - and the processes that modify them post release - on dry and wet deposition rates. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-03-13.

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14.

Radionuclide migration in fractured rock : Hydrological investigations at an experimental site in the Carnmennellis granite, Cornwall. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-03-27.

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15.

Out-of-pile ballooning and bursting tests on Zircaloy cladding rods with direct and indirect heating. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-09-24.

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16.

Results of temperature test 6 in the Asse salt mine. Volume I : main report. European Commission. DG XII – Science, Research and Development.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1986.

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17.

Barrier performance of cements and concretes in nuclear waste repositories. European Commission. Directorate-General for Research.

Publication

Luxembourg : Office for Official Publications of the European Communities, [2001], c2001.

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18.

EC static high-temperature leach test : Summary report of a European Community interlaboratory round robin. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-12-09.

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19.

Corrosion behaviour of container materials for geological disposal of high-level waste. Commission of the European Communities.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1985-04-12

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20.

Shared cost action - Reactor safety programme 1988-1991 : chemistry studies in support of Phebus-FP: Multicomponent aerosol behaviour. Volume II : Analyses. Commission of the European Communities. Joint Research Centre – Ispra.

Publication

Luxembourg : Office for Official Publications of the European Communities, 1991.

Summary

This is volume II of the report on "Chemistry studies in support of Phebus-FP: multicomponent aerosol behaviont", Nr. EUR 14005 EN. This part of the report deals with code analyses, the instrumentation and the seminars held on the Falcon project. Volume I summarises the Falcon project and describes the integral and the separate-effects experiments carried out. A major programme of integral tests has been completed in the Falcon facility at Winfrith. This two-year programme was designed to study the transport of fission product vapours and aerosols under severe accident conditions. Simulant or trace-irradiated fuel samples were heated up to 2000°K together with bulk-reactor materials, and the trans-port of the released fission products was followed through a pathway that simulated to some degree the upper plenum, hotleg structures and the containment. Various analytical techniques were used to provide information on the chemical species and physical forms of the release Mass spectrometry was developed to sample the high-temperature vapours at ambient pressure and determine their chemical forms, on-line gamma-ray spectroscopy was used to distinguish between gas-borne and deposited radionuclides, and speciation samplers (Maypacks) were used to follow the chemical behaviour of iodine within the containment vessel as a function of time. The experiments were designed and analysed with the assistance of modelling specialists to maximize the benefit of this work for the assessment and development of primary circuit and containment codes.

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