Liquidation of the Chernobyl Disaster Aftermath: Development of a Technology for Pyrolytic Processing, Disposal and Compacting of Combustible Radioactive Technogenic Waste
25.11.2002 21:56
Full Title: Liquidation of the Chernobyl Disaster Aftermath: Development of a Technology for Pyrolytic Processing, Disposal and Compacting of Combustible Radioactive Technogenic Waste
Tech Area / Field: ENV-RWT: Environment / Radioactive Waste Treatment
Status: 6 / Project underway
Deputy Executive Director: DED EU: Uwe Meyer
Senior Project Manager: Gennady Genrikhovich Kulikov, tel. 7+095+7976017, fax 7+095+7976021, kulikov@istc.ru
Project Officer/Assistant: Svetlana Vladimirovna Genisaretskaya, tel. 7+095+7976017, fax 7+095+7976021, genisaretskaya@istc.ru
Project Manager: Stesik L N
Phone: 7+095+9132310
Fax: 7+096+5153588
Leading Institute: Institute of Chemical Physics (1), Chernogolovka, Moscow reg., Russia
Supporting institutes: Keldysh Research Center, Moscow, Russia
Collaborators: University of California / Department of Mechanical Engineering, Berkeley, California, USA
Supporters: Research Institute for Mechanics of Quick-Proceeding Processes, Kiev, Ukraine
Project Summary
The objective of this proposal is the developing an efficient technology for processing combustible materials contaminated with radionuclides, and compacting of radioactive ash residue for its subsequent safe burial.
Great amount of combustible radioactive technogenic waste has been produced as a result of Chernobyl disaster, i.e., wood, peat, ground, clothes, oils contaminated with radionuclides, graphite thrown out from the reactor by explosion, etc. This waste is very dangerous because the atmospheric flows during fires in contaminated forests and ground and surface water lead to spread of radioactivity over large areas, to contamination, in particular, of drinking water supplies in residential areas.
Pyrolytic processing of such materials would provide concentrating of radionuclides in ash residue, which could be safely buried, similar to other radioactive wastes.
The proposed technique for pyrolytic processing is based on the method of gasification of solid fuels in the superadiabatic combustion wave, which has been developed in ICPC. The superadiabatic regimes of filtration combustion are extensively studied in ICPC during last 15 years. During this time a theoretical approach to the problem has been developed that accounts of effect of various factors (content of combustibles, dimensions of the fuel particles, oxidant flow rate and its composition) on velocity, temperatures and the structure of the combustion wave. Conditions for optimal regimes for processing certain combustible materials have been found. In parallel, experimental studies performed in ICPC and KRC provided a basis for technologies for processing municipal wastes, substandard coals & wastes of coal mining and coal enrichment, wastes of wood and pulp industry, wastes of petrochemistry, etc. To date patents are granted for methods for incineration of hospital wastes, processing solid municipal waste, processing worn-out tires; patent application for a method for processing wastes oils has been filed in.
Gasification of solid fuels in the superadiabatic combustion wave proceeds with the formation of carbon oxide, hydrogen and combustible tars from pyrolysis of organic ingredients of the initial fuel. With the necessary amount of oxygen being added the product gas is combustible and yields usual combustion products (carbon dioxide, water vapors). Specific features of gasification in superadiabatic regime are as follows:
- process can be performed for high-ash (to 90%) and highly humid initial fuel without external energy supply, even for that which is not combustible in other regimes;
- high energy efficiency (can be as high as 95%);
- solid fuel is burnt almost completely (the resulting ash/slag practically does not contain residual carbon and organic);
- amount of airborne solid particles at the reactor outlet is drastically decreased due to using of lumpy initial fuel and relatively low linear velocity of the gas flow in the reactor.
This Project on processing fuel contaminated with radioactivity is characterized by the following specific features:
- the necessity of performing gasification under reduced pressure in the reactor to exclude any exhaust of combustion solid products to atmosphere;
- gasification regimes should be developed for processing the specific wastes of Chernobyl nuclear power station (CNPS):
- developing of methods for preparation of initial materials, methods of their charging and discharging solid products of combustion which take into account the presence of contaminated materials;
- reliable trapping of the ash traces.
The Project is a complex of scientific investigations and engineering developments and involves:
1. Development of an optimum flow sheet of pyrolytic processing of radioactive technogenic waste.
2. Development of methods for trapping the products of pyrolytic processing of radioactive technogenic waste.
3. Choosing the methods of preparing the condensed pyrolysis products for burial.
4. Manufacturing of a pilot installation, based on the technology of pyrolytic processing of radioactive technogenic waste in the Chernobyl disaster area.
The scientific interest in the project is to determine the regularities of filtrational combustion for the systems with high content of incombustible, investigation of the structure of combustion wave and the composition of the gasification products.
The practical merit of the project is determined by its objective, i.e., development of a novel environmentally friendly and energy-saving technology for processing combustible radioactive wastes with ultimate compaction and burial of the condensed products of pyrolytic treatment.
The potential role of the foreign collaborators will be the regular discussion of the results obtained, consulting on the methods of investigations, etc.