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РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной.

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Presentation on theme: "РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной."— Presentation transcript:

1 РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики RUSSIAN ACADEMY OF SCIENCES Nuclear Safety Institute (IBRAE) RUSSIAN ACADEMY OF SCIENCES Nuclear Safety Institute (IBRAE) Experience in Analyzing Safety of SNF Management Back End in the Russian Federation Presented by Prof. Leonid A. Bolshov L.A. Bolshov, I.I. Linge, P.S. Kondratenko, I.V. Kapyrin, V.D. Kovalchuk May, 2010

2 www.ibrae.ac.ru 2 Outline  Motivation  Experience in groundwater flow and transport modeling  Non-classical transport processes in geologic media: Basic physical models Main factors determining anomalous transport in fractured media 1.Transport in random advection model 2.Random advection with finite correlation length 3.Contaminant transport over percolation media 4.Fluctuation aspects in transport over highly disordered media  Conclusions

3 www.ibrae.ac.ru 3 Motivation  Nuclear energy development program: –till 2015 – 234 bln. kWh/year (2009 – 163 bln. kWh/year) –after 2015 г. – annual grow of nuclear power not less than 2GWt.  Program «New generation nuclear energy techlogies (2010-2020)» –Innovative technologies for the conversion to closed SNF cycle –New generation fast power reactors  Program “Nuclear and radiation safety” (2008-2015) –Creation of an underground lab for SNF and HLW storage –Safe disposal of high level waste requires the solution of complex scientific problems

4 www.ibrae.ac.ru 4 ODC HOT-2 HOT-1 SNF management in the Russian Federation LWGR-1000 PWR-1000 PWR-440, FR RT-1 BilNPP (SNF reprocessing) ( SNF storage at GKhK) Remains at the Bilibino NPP Комплекс разделки GKhK SNF PA «Mayak»

5 www.ibrae.ac.ru 5 Plans of IBRAE for groundwater flow and transport modeling 1.Formalization of the process for constructing hydrogeological models and making calculations of safety parameters 2.Proper understanding of the underlying physical processes – non-classical models 3.Systematization of existing knowledge and software for continuum porous media models (clay, sand) 4.Development of the software for fractured media 5.Cooperation with institutions having experience of work at specific facilities

6 www.ibrae.ac.ru 6 Numerical modeling: model types –Dimension: 1D, 2D, 3D. –Media representation Continuum porous mediaDiscrete fracture network

7 www.ibrae.ac.ru 7 Model in development : PA “Mayak” groundwater flow Hydrogeological tasks:  Possible reservoirs overflow (accumulated 413 mln m 3 of liquid waste). Dangerous rise of levels observed during the years of high precipitation (2000-2003).  Transport of radionuclides from Karachai lake (120 mln Ci accumulated radioactivity).  Drainage of polluted waters into the surrounding channels.  Plenty of other near-surface RW storages.

8 www.ibrae.ac.ru 8 Kirovo-Chepetsk chemical combine Groundwater flow model using ModFlow Radionuclide transport model (MT3DMS)

9 www.ibrae.ac.ru 9 Experience in 3D: prospective SNF repository in France (test case) –Repository in clay –Heterogeneity (~1010) and anisotropy (~102) in the permeability tensor –Layer pinch-outs –Small thickness of the domain w.r. to diameter –Full heterogeneous (~10 5 ) diffusion-dispersion tensor.

10 www.ibrae.ac.ru 10 Modeling results: pressure and migration 3D view Vertical cross-section Horizontal cross-section

11 www.ibrae.ac.ru 11 Current problems: Laboratory in granite rock massif with possible SNF repository Fractured media model

12 www.ibrae.ac.ru 12 Non-classical transport processes: Key factors and physical concepts  Key physical factors determining anomalous transport in fractured media 1.Natural fracture networks exhibit fractal properties and can be classified as percolation media 2.Random advection as dominating transport mechanism 3.Sharp contrast in medium characteristic distribution 4.Strong spatial fluctuations of moisture seepage characteristics  Concepts 1.Critical phenomena theory 2.Feynmann’s diagram techniques 3.Mesoscopic effects in semiconducting tunneling barriers

13 www.ibrae.ac.ru 13 Non-classical transport processes: 1. Transport in Random Advection Model Various concentration asymptotics at large distances (tails) h>1 : classical diffusion h<1 : super-diffusion, exponential decay in concentration tail No heavy tails Statement of the problem Results

14 www.ibrae.ac.ru 14 Non-classical transport processes: 2. Random Advection with Finite Correlation Length Change of transport regimes with time (schematic) Two-stage concentration tail (schematic) Statement of the problem

15 www.ibrae.ac.ru 15 Non-classical transport processes: 3. Contaminant Transport in Percolation Media Transport regimes above the percolation threshold (schematic) Two-stage concentration tail above percolation threshold (schematic) Statement of the problem Governing equation: Results

16 www.ibrae.ac.ru 16 Non-classical transport processes: 4. Fluctuation Aspects (cont’d) CSCS N F CS contaminant source N near-field zone F far-field zone Statement of the problemResults Large area of Strong renormalization of the contaminant source power (factor K) Large area of the contact surface between medium and contaminant source: Small area: Strong renormalization Large statistical scatter of the K- factor

17 www.ibrae.ac.ru 17 Conclusions  Either closed SNF cycle or final direct SNF disposal require safety assessment techniques  Numerical groundwater flow and radionuclide transport models are regarded as the main tool in the safery assessment. Their development is considered as one of the key goals  Four physical models presented above manifest main feature of geological media giving rise to non- classical contaminant transport. The contaminant concentration at large distances (in tail) decays exponentially in both super- and sub-diffusive transport modes. Spatial fluctuations of medium properties can lead to a significant renormalization of contaminant source power

18 РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики РОССИЙСКАЯ АКАДЕМИЯ НАУК Институт проблем безопасного развития атомной энергетики RUSSIAN ACADEMY OF SCIENCES Nuclear Safety Institute (IBRAE) RUSSIAN ACADEMY OF SCIENCES Nuclear Safety Institute (IBRAE) THANK YOU FOR YOUR ATTENTION


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