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SARNET – Severe Accident Research Network
University of Manchester School of Mechanical Engineering, G. Begg Building
CFD Workshop on Test-Cases, Databases & BPGfor nuclear power plants applications
16th July 2008
M. Reeks1 and T. Haste2,1
1University of Newcastle-upon-Tyne2PSI Villigen, Switzerland,
SARNET – CFD Workshop, University of Manchester, July 2008 2
OVERVIEW
SARNET is a Network of Excellence in the Nuclear Fission area of the EU 6th Framework Programme, with the general aim of integrating in a sustainable manner European research on severe accident phenomenology in light water reactors
The network started in April 2004 and will finish in September 2008; a successor project is being negotiated for a further 4 years in the 7th Framework programme
After a brief summary of project organisation and aims, this presentation indicates how CFD methods are used in the project overall, with focus on the Source Term area, that studies the release and transport of radioactive fission products from the reactor core to the environment
INTRODUCTION
T Albiol et al. ‚ SARNET: Severe Accident Research Network of Excellence, ICONE15, Nagoya, Japan, April 2007
SARNET – CFD Workshop, University of Manchester, July 2008 3
SevereAccidentResearchNETwork of excellence
Currently:
– 18 European Countries and Canada
– 51 organizations
19 Research organizations
10 Universities
11 Industry organizations
4 Electricity producers
7 Safety authorities and technical support organisations
– More than 230 researchers
– About 20 PhD students
– 800 to 900 person-months per year
– About 10M€ effort per year (1.6M€ funded by the EC per year)
www.sar-net.org
SARNET – CFD Workshop, University of Manchester, July 2008 4
SARNET OBJECTIVES
Resolution of still pending issues important for reactor safety
Optimised use of available resources and competences on severe accidents throughout Europe
Knowledge transfer for safety application
Perpetuate the competence on severe accidents
Encapsulation of the knowledge base on severe accidents through the lumped-parameter ASTEC code
– this program calculates the progress of severe accidents in light water reactors from initiating event through to release of radioactive fission products to the environment
– it enables the results of the scientific research to be used in reactor applications
MAIN OBJECTIVES
SARNET – CFD Workshop, University of Manchester, July 2008 5
SARNET ACTIVITIES
SARNET is organised into a number of work packages covering
– integrating activities (such as research prioritisation, database management, ASTEC development)
– jointly executed scientific research (focussed on corium, containment and source term matters), and
– spreading of excellence (such as organisation of training courses and mobility of researchers)
CFD is one of a number of analysis methods used in the jointly-executed scientific research (‘topical’) areas
– used in all these areas, but mainly for containment and source term studies
ORGANISATION
SARNET – CFD Workshop, University of Manchester, July 2008 6
WORK PACKAGES
WP 17 : ETEducation and Training
WP 18 : BOOKBook on severe accident phenomenology WP 19 : MOBMobility programme
Spreading of excellence activities
Integrating activities Jointly executed research activities
WP 1 : ACTDevelopment of an Advanced Communication Tool
WP 6 : IEDImplementation of Experimental Database
WP 7 : SARPDefinition of Severe Accident Research Priorities
WP 8 : IAIntegration Assessment
WP 2 : USTIAASTEC Users Support and Training, Integration, and Adaptation WP 3 : PHYMAASTEC PHYsical Model Assessment
WP 4 : RABASTEC Reactor Application Benchmarking
WP 14,15,16 : SOURCE TERMFP Release and TransportAerosol Behaviour impact on Source TermContainment Chemistry impact on Source Term
WP 20 : Management
WP 12,13 : CONTAINMENTHydrogen behaviour Fast Interaction in Containment
WP 9,10,11 : CORIUMEarly phase core degradation Late phase core degradationEx-vessel corium recovery
WP 5 : PSA2Level 2 PSA methodology and advanced tools
SARNET – CFD Workshop, University of Manchester, July 2008 7
DATABASE
MEDICIS/WEXRUPUICUV
SYSINT
ISODOP
SOPHAEROS
Aerosols and FPIn the reactor circuits
SYSINT
ISODOP
IODE
CPA-AFP
CPA-THY
MEDICIS/WEX
RUPUICUV
SOPHAEROS
CESAR
ELSA
DIVA
t
t
t
t
t
t
t
t
t
t
Safety systemmanagement
IODE
Molten core concreteinteraction
Radioactivity inContainment
ELSA
FP relaese
DIVA
Core degradation
CESARCircuit
Thermalhydraulics
CPA-THY
ContainmentThermal hydraulics
CPA-AFP
Aerosols and FP incontainment
Molten core ejectionAnd direct heating
Of containment
Integral numerical simulation of reactor accident with core melting (Severe Accidents)
IRSN-GRS property : ~ 10 m-y/y in charge of software development and user support
Has been distributed to 26 SARNET organizations
SARNET scientists support for model improvement and physical assessment:
ASTEC capitalizes, in terms of models, all the knowledge produced in the frame of the Network
40 trained users contribute to joint validation programme (mobilizes around 20 m-y/year)
One major version delivered in July 2005 (V1.2)
Size: ~ 350 000 instructions
Speed: ~ 3-10 hours to compute 24 h of transients
ASTEC
ASTEC integrates the technical knowledge in SARNET
SARNET – CFD Workshop, University of Manchester, July 2008 8
USE OF CFD METHODS IN SARNET CFD is used in a number of applications, such as
– design of experiments
– interpretation of experimental results
– plant studies, e.g. to determine the parameter ranges for separate-effect tests
– benchmarking system-level codes, in this case principally ASTEC
– one also notes use in reactor applications outside SARNET to look at detailed aspects where lumped-parameter methods are not sufficient, e.g. where 3-D flows are important, CFD results can be used to guide the use of lumped parameter codes regarding noding, X-flow resistances, other tuneable parameters etc.
Validation of CFD methods and development of best practice per se are not main aims within SARNET
– the codes are applied rather than developed and validated, and the users are assumed to know how to use their codes effectively
– note also the CFD activities within OECD/NEA/GAMA, http://www.nea.fr/html/nsd/csni/cfd.htm, with best practice guidelines, http://www.nea.fr/html/nsd/docs/2007/csni-r2007-5.pdf, these are not within SARNET but many of the same organisations are involved
USE OF CFD - GENERAL
SARNET – CFD Workshop, University of Manchester, July 2008 9
CONTAINMENT STUDIES Examples are:
– Interpretation of results from the TOSQAN and MISTRA tests on influence of containment sprays on the atmosphere behaviour (depressurisation, gas mixing), comparison of LP and CFD methods, see also OECD International Standard Problem 47 report http://www.nea.fr/html/nsd/docs/2007/csni-r2007-10.pdf
– Investigation of processes inside passive autocatalytic recombiners (PARs) using data from the REKO-3 facility, influence on the containment atmosphere and of steam condensation, hydrogen recombination, effects of steam and oxygen depletion
– Investigation of hydrogen combustion using data from the ENACCEF facility, effect of concentration gradients on flame acceleration/deceleration
USE OF CFD – CONTAINMENT STUDIES
H Wilkening et al. ‚ European Research on Issues concerning Hydrogen Behaviour in Containment within the
SARNET Network of Excellence , ICAPP’08, Anaheim, USA, June 2008
SARNET – CFD Workshop, University of Manchester, July 2008 10
USE OF CFD – CONTAINMENT STUDIES
H Wilkening et al. ‚ op cit.
SARNET – CFD Workshop, University of Manchester, July 2008 11
SOURCE TERM STUDIES Examples are:
– Reactor calculations in combination with other codes such as the LP programs ICARE/CATHARE and ASTEC to determine gas flows and compositions that may result from air ingress into the vessel following hot leg and lower head breach (EdF, IRSN), determining conditions for separate-effect tests on air oxidation of fuel and cladding
– Design calculations for facilities investigating the dynamic chemical interactions of iodine-containing and ruthenium-containing species in the primary circuit under severe accident conditions (IRSN, VTT)
– Interpretation of circuit chemistry aspects of the Phebus-FPT2 integral in-reactor experiment on core degradation, and fission product release and transport, and behaviour in-containment (IRSN)
– Interpretation of an integral ThAI experiment (Becker Technologies) on iodine behaviour in-containment coupled with thermal hydraulic and aerosol aspects, in the frame of a SARNET benchmark led by GRS with contributions from GRS, IRSN and AECL
– Investigation of results of the RECI experiments (IRSN) on the effects of PARs on airborne iodine in the containment (IRSN, Demokritos, et al.)
USE OF CFD – SOURCE TERM STUDIES
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USE OF CFD – SOURCE TERM STUDIES
A Auvinen et al. ‚ Progress on Ruthenium Release and Transport under Air Ingress Conditions, ERMSAR2007, FZ Karlsruhe, June 2007
SATURNE calculation of flows in the lower head and cavity under air ingress conditions (EdF)
Reactor meshing for CFD calculation (Saturne)
Refined meshing in the annulus zone
Coarse meshing in the dome
40.000 to 60.000 cells
SARNET – CFD Workshop, University of Manchester, July 2008 13
USE OF CFD – SOURCE TERM STUDIES
http://www.becker-technologies.com/web-e/html/Reaktorsicherheit/thai-anlagen.html
Illustrations of the ThAI facility
SARNET – CFD Workshop, University of Manchester, July 2008 14
CONCLUDING REMARKS
CFD methods have an important role within SARNET for support of experiments, in plant studies and for benchmarking more detailed models, for example in the major European severe accident analysis code ASTEC, that is a main product of the network
The focus is on application rather than on development and validation The applications are mainly in the areas of containment studies, and in
source term research It is expected that CFD methods will continue to be used in the follow-
on SARNET2 project in the 7th Framework programme, subject to the satisfactory outcome of negotiations with the EC that are currently in progress
CONCLUSIONS
The authors thank the European Commission for funding SARNET, in the 6 th Framework Programme area “Nuclear Fission: Safety of Existing Nuclear Installations”, under contract number FI6O-CT-2004-509065.