Off-Gas Cleaning from Semivolatile Radionuclides
Innovative Method of Gas Purification from Semivolatile Radionuclide Using Porous Inorganic Materials
Tech Area / Field
- ENV-RWT/Radioactive Waste Treatment/Environment
8 Project completed
Senior Project Manager
Genisaretskaya S V
Khlopin Radium Institute, Russia, St Petersburg
- NPO Mayak, Russia, Chelyabinsk reg., Oziorsk
- L. J. Jardine Services, USA, CA, Dublin\nSCK-CEN, Belgium, Mol\nImperial College London / Department of Materials, UK, London\nIdaho National Engineering and Environmental Laboratory, USA, ID, Idaho Falls\nUniversity of Sheffield / Department of Engineering Materials / Immobilisation Science Laboratory, UK, Shiffield
Project summaryThe 137Cs in form of the close powerful irradiation sources (CPIS) is related to the most wide–useful radionuclides in the different areas of the people activity.
CPIS are applied for:
- ecological problem solution;
- industrial application;
- irradiation treatment of the products of the food industry and agriculture to save them;
- sterilization of the useful medical materials before utilization.
137Cs application has a wide range and a big volume due to two reasons:
- use of irradiation-physical characteristics (a big half-life period of 30.18 years, a strong hard γ–radiation with energy Eγ=661.66 KeV, a quantum yield of I=0.85 quantum/decay) in not nuclear area is considered as a strong incentive to the practical realization of liquid HLW partitioning process on the international level;
- 137Cs production in a big amount during liquid HLW partitioning results in the additional economical effect.
The 137Cs irradiation application cannot be extended extensively due to obvious disadvantages of the useful core as 137Cs chloride and CPIS production technology on its base. These disadvantages are as follows: a high solubility of this salt can result in the severe ecological consequences and sacrifices including possibility of uncontrolled stealing with terrorist purposes; the frequent equipment turnover because of corrosion-dangerous cesium chloride; production of great amount of secondary waste.
There are no above-mentioned disadvantages, if the employed CPIS cores are glass or ceramics. However, 137Cs has the higher volatility during high-temperature synthesis of these cores like the initial sludge heating, vitrification or ceramics sintering.
Two method of 137Cs vapor trapping are possible. They are 137Cs saturation from vapor-gas phase in the liquid bubblers and 137Cs chemical adsorption by the filters from the porous inorganic materials (PIM).
It is appropriate to use the alumina silicate amorphous (or with a high amorphous phase content) PIM as the filters for 137Cs chemical adsorption. The amorphous phase of the PIMs such type has an increased reactivity and can interact with 137Cs to form the stable alumina silicate crystalline phases namely CsAlSiO4 (Cs-calsilit) and CsAlSi2O6 (Cs-pollucitte).
Realization of this Project in Russia aims to solve the problems of 137Cs effective trapping, as well as other semivolatile radionuclides forming during fabrication of glassy and ceramic cores of CPISs at FSUE “Mayak” PA”.
The main activity directions will be:
- Fabrication of PIM blocks with desired properties on porosity and the amorphous phase content.
- Efficiency experimental analysis of the different alumina silicate PIM for Cs trapping from gas phase.
- Determination of the PIM filters optimal temperature for cesium chemical adsorption.
- Study of the microstructure, chemical and phase composition of PIM with sorbed cesium.
- Determination of PIM capacity on cesium under static and dynamic regimes.
- PIM compacting with saturated cesium by vitrification method and “cold” pressing followed by sintering.
- Determination of PIM chemical stability with sorbed cesium.
- Development of the filter-chuck with PIM for cesium trapping and test under real conditions.
- Study of other semivolatile radionuclides trapping by PIM impregnated with inorganic sorbents.
- Development and application of a new trapping technology for 137Cs formed during fabrication of CPIS glassy cores at FSUE “Mayak” PA”.
- Issue of the technical documentation for the filter assembly with PIM fabrication.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.