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Chemical Explosions

#0124


Initiation and development of chemical (chain and thermal) explosions in reactors and energy-producing apparatus.

Tech Area / Field

  • FIR-NSS/Nuclear Safety and Safeguarding/Fission Reactors

Status
8 Project completed

Registration date
02.12.1993

Completion date
24.01.1999

Senior Project Manager
Tocheny L V

Leading Institute
Institute of Problems of Chemical Physics, Russia, Moscow reg., Chernogolovka

Collaborators

  • Inburex GmbH, Germany, Hamm\nBritish Gas, UK, Loughborough\nEuropean Commission / Joint Research Center / Institute for Systems, Informatics and Safety, Italy, Ispra

Project summary

The goal of the project is a complex research and prognosis of initiation, development and environmental influence of chemical (chain and thermal) self-ignition, explosion and detonation in reactors and apparatus of energy-generating, chemical and related industries, those-based creation of a quantitative scenario of possible accidents and drawing up recommendations on their elimination or diminishing of possible damage, as well as obtaining initial data to devise the methods of localization and liquidation of consequences.

Considerable advances have been made by a number of large scientific teams in the study of these processes. There were created general theoretical views, developed experimental and calculation techniques aimed at analysis and prognosis of the processes taking place. However in most cases there are no full data on kinetics and mechanism of chemical reactions, accounting for explosion initiation and development, as well as on peculiarities of the explosions proceeding in complex chemical media. Such processes as explosion and combustion initiation are being considered without regard to their influence on surrounding apparatus and buildings.

Me suggest to perform a complex research resulting in the creation of interrelated calculation programs, as well as in the obtaining of the initial experimental and theoretical characteristics of the processes and their mutual influence. Also elaborated or adapted will be the appropriate research methods, providing enough accuracy.

To select the subjects and processes to be explored we used the analysis data on accident explosions and fires in Chernobyl, Tomsk-7, chemical, pharmaceutical and explosives industries.

The research includes studying the process on various levels and stages with taking into account their mutual influences:

- Theoretical study on elementary chemical reactions playing the main role in the shock wave front.

- Experimental and theoretical exploration of high temperature hydrogen oxidation kinetics in oxyhydrogen gas mixtures with taking into account the influence of additives and penetrating radiation . Determination of the explosion initiation critical conditions, concentration limits and induction periods.

- Theoretical and experimental study on peculiarities of chain processes development in shock waves, related with non-equilibrium process of translational relaxation at shock wave front (possible expansion of concentration limits, reduction of the induction period) dependent on molecular-mass composition of a mixture, shock wave velocity and other parameters.

- Kinetic exploration of organic substances oxidation by nitric acid in relation to reagents' nature and concentrations, medium acidity, radiation effect, nitrogen oxides pressure, etc. Measurement of thermal effects.

- Study on metals and other materials combustion in oxygen and water-containing media using zirconium and carbon as an example. Investigations on kinetics and thermodynamics of these processes, ignition conditions, heat evolution rate, formation regularities of the explosive gases such as hydrogen, carbon monoxide, etc.

- Quantitative generalization and recasting of the resulted kinetic information in the form suitable for macroscopic calculations.

- Development of the thermal explosion theory as applied to continuous and batch reactors to obtain the quantitative characteristics of thermal explosion (critical conditions, the induction period, etc.) on the basis of kinetic data, heat transfer conditions and reactor design.

- Experimental testing of the theory on model systems.

- Development of a three-dimensional method for quantitative simulation of shock and detonation waves propagation and interaction, shock initiation of detonation in buildings of various geometry. Resulting determination of the building destruction conditions.

- Development of a modeling technique and an investigation of spall fragments (parts of a broken reactor) effect on neighboring equipment and buildings.

- Kinetic study on concrete thermodestruction under high temperatures, followed by creation of a quantitative calculation technique for destruction wave propagation along macroscopic samples under high temperatures, including their contact with a melted metal.

- Development of a method for registration and analysis of dust-like radioactive particles forming at explosion and combustion of the reactor materials. Selection and the whys and wherefores of track a-detectors and their development technique. Investigations of physicochemical processes, evaporation kinetics of radioactive elements and that of their condensation with the formation of aerosol.

- Resulting creation of the quantitative scenario of possible accidents and drawing up the recommendations on their elimination or diminishing of possible damage as well as initial data securing to develop the methods of localization and liquidation of consequences.


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