Apr 18 – 23, 2010
Casino Conference Centre
UTC timezone

Study of new filter properties <sup>137</sup>Cs vapour capture at high temperature

Apr 22, 2010, 12:00 PM
1h 30m
Gallery (Casino Conference Centre)

Gallery

Casino Conference Centre

Reitenbergerova 4/95, Marianske Lazne, Czech Republic
Board: NFC.P13
Poster Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management Poster Session - Chemistry of Nuclear Fuel Cycle, Nuclear Waste Management

Speaker

Dr Albert Aloy (Khlopin Radium Institute)

Description

Vitrification of radioactive wastes and high temperature synthesis of glass and ceramics for ionizing radiation sources, containing Cs-137, is accompanied by discharge of its vapours. The off-gas contaminated by Cs-137 must be cleaned up using different trapping systems. In general two methods of Cs-137 vapour catching are possible, differing both in process character (nature) and realization place in technological scheme: · "wet" method – "low-temperature" Cs-137 vapour condensation in system of gas cleaning (condensers, scrubbers, HEPA-filters). This method leads to contamination of communications and to formation secondary liquid RAW, which require additional repossessing. · "dry" method – "high-temperature" Cs-137 vapour chemisorptions. This method allows fixing Cs-137 in stable crystalline and amorphous phases. Earler it was shown that porous inorganic materials with high content of silica- alumina amorphous phase could be used for effective capturing of Cs-137 vapours. Effectiveness of filter depends on the total porosity; porous structure and aerodynamic resistance to off-gas flow. To study these parameters a laboratory scale test facility was built at the KRI. The following three methods are used to evaluate dust and aerosol capture efficiency at room temperature: · weighing method: sample the dust using special certificated analytical filters followed by weighing of the absorbed precipitate. The filters are sealed in the filter holders; · radiometric method: if an isotope spike is used, the dust is sampled using the analytical filters as described above followed by measurements of absorbed activity using conventional methods; · aerosol particle concentration measurements: using laser counters for aerosol particle concentrations. This method determines fraction decontamination factors for the particle sizes ranging from 0.2 to 5 µm. Report will summarize obtained analytical data and describe the dependence of filter effectiveness at different rates off-gas flow.

Primary author

Dr Albert Aloy (Khlopin Radium Institute)

Co-author

Mrs Irina Shasmolova (Khlopin Radium Institute)

Presentation materials

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