Safety of Thermal Water Reactors: Proceedings of a Seminar on the Results of the European Communities' Indirect Action Research Programme on Safety of

ISBN-13: 9789401087018 / Angielski / Miękka / 2011 / 613 str.

E. Skupinski; B. Tolley; J. Vilain

Opis

The European Community's Indirect Action Research Programme on the Safety of Thermal Water Reactors had as main obj ectives to execute useful fundamental research, complementary and confirmatory to on-going work in national programmes, and to improve collaboration and exchange of inform ation between laboratories in the Member States. The Seminar was aimed to report on work performed during the last five years and to identify useful further research areas with a tentative assessment of the state of the art for future work in certain issues of LWR-safety. The results obtained in 33 research projects executed in different national laboratories of the European Community were presented, evaluated and discussed, together with a number of invited papers on topics related to the research programme. Topics covered mainly within 3 distinct research areas or sub-programmes: Research Area A: The loss of coolant accident (LOCA) and the func tioning and performance of the emergency core cooling system (ECCS). Fundamental work on thermalhydraulics and heat transfer during refill and reflood of an uncovered core after a LOCA. Research Area B: The protection of nuclear power plants against external gas cloud explosions. Study of the impact on plant structure and systems of external explosions of dense combustible gas clouds due to accidental releases of hydro carbons in the vicinity of the plant. Research Area C: The release and distribution of radioactive fission products in the atmosphere following a reactor accident."

Spis treści

Abbreviations.- Abbreviations.- Opening plenary session.- Welcome address.- The CEC Research Action Programme on the Development of Nuclear Fission..- The CEC Indirect Action Research Programme, Safety of Thermal Water Reactors (1979–1983): Aims, contents and implementation.- Parallel session Research Area A.- The loss of coolant accident (LOCA) and the functioning and performance of the emergency core cooling system (ECCS)..- Session A1.- Important thermohydraulic aspects during refilling and reflooding of an uncovered LWR core..- Studies on the effects of blockage upon LWR emergency core cooling systems..- Session A2.- Droplet dynamics and heat transfer in dispersed two phase flow..- An experimental investigation of the effect of clad ballooning on the effectiveness of PWR emergency core cooling.- Out of pile ballooning and bursting tests on Zircaloy cladding rods with direct and indirect heating..- General Discussion on sessions A1 and A2.- Session A3.- 2D effects in the core during the reflooding phase of a LOCA..- Fluid dynamic effects in the fuel element top nozzle area during refilling and reflooding..- Study of rewetting and quench phenomena by single pin out-of-pile experiments, with special emphasis on the effect of pin composition..- Heat transfer to a dispersed two-phase flow and detailed quench front velocity research.- Session A4.- Rewetting propagation over Zircaloy under bottom flooding conditions..- The Role of Experiments in The Development and Qualification of Thermalhydraulic.Codes, As Experienced in The Development of The CATHARE Code.- Parallel sessions Research Area B.- The protection of nuclear power plants against external gas cloud explosions.- Session B1.- Large-scale field trials on dense vapour dispersion..- Aspects of the dispersion of denser-than-air vapours relevant to gas cloud explosions..- Session B2.- Verification of heavy gas models on the basis of large-scale experiments.- Computer processing of visual records from the Thorney Island large scale gas trials..- Transition from slow deflagration to detonation..- On the propagation of the pressure pulse due to an unconfined gas cloud explosion. Theoretical analysis..- Session B3.- Gas cloud explosions and their effect on nuclear power plant, basic development of explosion codes..- Validation of blast simulation codes and experimental investigation of flame propagation in the presence of obstacles..- Characterization of the pressure field induced by the explosions in air of a hydrocarbon-air mixture, with slow deflagration or fast deflagration..- Experimental investigation of the acceleration of deflagration in wake flow..- Session B4.- Calculation of overpressures on the buildings of a power plant due to the passage of a shock wave caused by an accidental explosion..- Blast wave propagation and the influence of obstacles..- Calculation of the wall pressure field generated on a group of buildings by an external explosion..- Recent results of experimental studies on the transition of a deflagration into a detonation and some aspects for the transposition of these results to confined explosions..- Parallel sessions Research Area C.- The release and distribution of radioactive fission products in the atmosphere following a reactor accident..- Session C1.- Review of specific effects in atmospheric dispersion calculations..- The effects of buildings on low level atmospheric discharges..- Session C2.- Predicting lift-off of major self-heating releases under the influence of a building..- Development of an integral model of a radioactive jet released accidentally from a nuclear reactor..- Development of a prototype mesoscale computer model, incorporating treatment of topography..- Finite element three-dimensional formulation of a variational procedure of wind field adjustment over a domain of complex topography..- Description of a recent nordic mesoscale dispersion experiment over a land-water-land area (the Oresund Experiment)..- Session C3.- Wind tunnel modelling of turbulent diffusion of pollutant puffs..- Physical model of the dispersion of a radioactive contaminant in the atmosphere above a “heat island”..- Wind Tunnel Simulation of Atmospheric Dispersion in Stable Conditions at a Real Site..- Assessment of the dispersion of fission in the atmosphere following a reactor accident under meteorological conditions of low wind speed..- Session C4.- Local-scale atmospheric diffusion at a coastal site, in the presence of breeze effect..- Sensitivity, applicability and validation of bi-Gaussian off-and on-line models for the evaluation of the consequences of accidental releases in nuclear facilities..- Interlaboratory comparison of SF6 — Determination used within the framework of tracer releases..- Estimates of uncertainty in dispersion modelling..- Concluding plenary session.- Overview and conclusions on the results obtained in research Area A: The loss of coolant accident (LOCA) and the functioning and performance of the emergency core cooling system (ECCS)..- Overview and conclusions on the results obtained in research Area B: The protection of nuclear power plants against external gas cloud explosions..- Overview and conclusions on the results obtained in research Area C: The release and distribution of radioative fission products in the atmosphere following a reactor accident..- The CEC — Research Action Programme on Reactor Safety (1984–1981).- Developments in Nuclear Safety Research..- Concluding panel.- Evaluation of the results of the present Indirect Action Research Programme Safety of LWR. State-of-the-art in LWR Safety Research. Identification of useful topics for future research, with special consideration of Conmnunity programmes..- Closing address.- List of participants.- Index of authors.