Multiscale integral analysis of non-operational tritium ... Meeting... · • Future fusion reactors will breed tritium from other elements to use it as fuel. Hence, the need for
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tritium leakages in nuclear power plantsTritium analysis team
J. Fradera1, M. Velarde2, C. Colomer1, P. Briani1, E. Martínez-Saban1, I. Zamora1, M. Fabbri1, A.Janés1, A. Alemán1, J. M. Perlado2
1 IDOM nuclear services, Gran Vía Carlos III, 97 bajos, 08028, Barcelona, Spain2 Institute of Nuclear Fusion–Polytechnological University of Madrid, José Gutiérrez Abascal 2, 28006 Madrid (Spain)
• Tritium leakages are currently a major concern regardingexisting nuclear power plants.
• Future fusion reactors will breed tritium from otherelements to use it as fuel. Hence, the need for preventingand containing tritium leakages turns out to be a key issue.
• A methodology for multiscale integral analysis of tritiumleakages with dedicated computational tools will be apowerful tool from the design, operation and safety point ofview.
• Develop an integral methodology as a decided step towardsa standard for safety analysis regarding tritium leakages tothe environment.
• Define all necessary interfaces between different scaleanalysis, e.g., CFD to System Codes to atmospherictransport.
• Assess tritium cloud patterns (cyclonic and anticycloniccirculations) including the definition of significant scenarioswhich lead to maximum concentrations in tritiated clouds atshort range.
• Ensure the reliability and accuracy of future analysis with arobust methodology and best practices, focused on safety.
• Complex physics and sophisticated modelling is needed in order to assess tritiumleakages from the component level to the atmospheric transport.
• Convection• Diffusion (thermomigration, electromigration, trapping)• Tritium chemistry• Isotopic exchange• Recombination and deposition processes in the soil• Penetration in the underground• Re-emission and later conversion to organic bound tritium (OBT)• Dosimetry (inhalation, re-emission and ingestion (early and chronic doses)
T transport phenomena under nuclear condition with He nucleation.
• Idom is currently developing iMOL, a tritium transport parallel system code.• Codes like MELCOR (fusion version), MAAP, GOTHIC, FATHOM, IMPULSE, TMAP… can also be used.• iMOL can be coupled to these codes
• Topological events• Plume rise• Building wake effects• Shoreline fumigation• Atmospherical conditions outline detailing the measures in real time• Use of Spanish Meteorological Agency data
• The low solubility of the elementary tritium causes deposition, mainly inHTO form, under rainfall events. The deposition rate is essential for tritiumremoval process on the ground. This parameter is the great importance inall of the secondary phase, when the tritium is incorporated to thebiological system.
Construction of an INDIVIDUAL ISFSI in Ascó NPP | 25
Demographic, nutritional and agricultural data are used for the bestapproximation and adapted to entry-format of calculation tools.
• The probabilistic sampling scheme based on hourly data is detailed.These studies provide the real dynamics of the processes, which aredifferent from deterministic case
• Different soil type is considered
• Three compartments levels of underground
• Soil organic matter included in the components (non-humidsubstances)
• New parameters: LAI (Leaf Area Index), photosynthesis , respiration,water and organic matter content.
• This tritium form that can remain long time in the organism: OBT has longer retention times than tritiated water (amino acids, sugars, protein, starches, lipids cell structural materials)
• Following OBT intake. Ingestion is more hazardous RBE (Relative Biological Effectiveness), wR Transmutation effects LET (Low-linear energy transfer for internal dosimetry, ionisation-density) Incorporattion in DNA and RNA Distribution effects
• Level of safety required of the International Commission on Radiological Protection (ICRP)
• Recomendations concerning of the Commited effective Dose Equivalent for public, 1mSv/year
• All systems are needed to minimize chronic and accidental emissions
The tritium analysis team is a collaboration program between theNuclear Fusion Institute (IFN) at UPM and Idom Nuclear Services withthe aim of develop tools and methodologies for tritium transportphenomena.