Presentation of SARNET2

1
Presentation of SARNET2
T. Albiol (IRSN), J.P. Van Dorsselaere (IRSN), W.
Tromm (FZK), C. Journeau (CEA), I. Kljenak (JSI),
T. Haste (PSI), B.R. Sehgal (KTH), D. Beraha (GRS)

• ERMSAR 2008
• Nesseber, Bulgaria, September 23-25, 2008

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SARNET2 General Objectives integration,
diffusion of knowledge, sustainability

• To tackle the fragmentation existing in
  defining/carrying out research programmes between
  different countries
• To diffuse the knowledge to the stakeholders,
  especially in the new EU member states, more
  efficiently, and associate them to the definition
  and the conduct of the research programmes more
  closely
• To bring together top scientists in severe
  accident research so as to be the world leader in
  advanced computer tools for severe accident risk
  assessment
• To perform significant progress towards the
  closure of the remaining high priority issues in
  the domain of severe accidents (see next slide)
• To establish a self-sustaining organization in
  the field of severe accident research through
  activities in networking, integration, knowledge
  management, exchange of information,
  dissemination of results and training in order to
  keep the competence in severe accident management
  alive in Europe and worldwide.

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SARNET2 Scientific Objectives

• Efforts put on the 6 high priority issues as
  determined in SARNET / SARP WP
• core coolability during reflood and debris
  cooling
• ex-vessel melt pool configuration during MCCI
  ex-vessel corium coolability by top flooding
• melt relocation into water ex-vessel FCI
• hydrogen mixing and combustion in containment
  (flame acceleration)
• oxidising impact on source term (Ru oxidising
  conditions or air ingress for HBU and MOX fuel
  elements)
• iodine chemistry in RCS in containment
• Special focus in the SARNET2 JPA on the corium
  issues (coolability and MCCI), including major
  experimental activities
• Strong cooperation with international programmes
  such as Phébus FP, ISTP, ISTC, OECD/CSNI GAMA, ...

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SARNET2 Partners

• 41 partners
• 8 universities
• 23 research organisations
• 5 industry / utilities
• 5 TSOs / safety authorities
• 21 countries (18 European countries, USA, Canada,
  Korea)

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SARNET2 Organisation scheme
Steering Committee (Core Group)
General Assembly
Information Consultation
Submission of Programme Proposals
Executive line
Proposal line
Advisory Committee
Management Team
EC
Control line on SARP programme proposals
(attribution of SARNET label)
Coordinator
WP leaders
Executive line
WP 1
WP 8
WP N
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SARNET2 Organisation in Work-Packages (as of
Sept. 03, 2008)
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SARNET2 Work-Packages (1 and 2 / 8)

• WP1 Management (MANAG)
• Coordination, administration and budget. Links
  with the EC and the Core Group. Creation of a
  legal entity for the long term self-sustainability
  
• Assessment of progress and results
• Periodic updates of the research priorities,
  including definition of needed research
  programmes and consensus on closure of issues
  in link with PSA2 specialists, industry (advisory
  committee) and international organizations (OECD,
  ISTC, ...)
• WP2 Spreading of Excellence (SE)
• Organization of three courses on severe accidents
  targeted to students and severe accident
  specialists in link with the ENEN.
  Organization of one Information Day targeted to
  NPP Managers.
• Organization of periodic ERMSAR Conferences
• Mobility Programme

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SARNET2 Work-Packages (3 and 4 / 8)

• WP3 Information Systems (IS)
• SARNET2 Web site ? large improvements expected
  compared with the current SARNET Web site
• Advanced Communication Tool ? same general
  features as the SARNET ACT. Aim at an even more
  extensive use within SARNET members
• Experimental database ? stake long term data
  storage in a common standard
• WP4 ASTEC (ASTEC)
• Continue to integrate in ASTEC the knowledge
  gained
• Code assessment through plant applications
  (various NPPs types and various scenarios) and
  sensitivity studies
• Continue investigations on coupling ASTEC and
  PSA2 tools
• Continue ASTEC adaptation to other types of
  water-cooled reactors in Europe BWR, CANDU
• Continue maintenance, users support (30 SARNET2
  partners will use ASTEC)

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SARNET2 Work-Packages (5 / 8)

• WP5 Corium and Debris Coolability (COOL)
• Major motivation reduce or possibly solve
  remaining uncertainties on the possibility of
  cooling structures and materials during severe
  accidents
• Either in the core
• Or in the reactor pressure vessel lower head
• Or in the reactor cavity
• Issues to be covered
• Within the scope of accident management for
  existing reactors
• Also within the scope of design and safety
  evaluation for future ones
• 3 key situations and processes considered
• Reflooding and coolability of a degraded core
• Remelting of debris, melt pool formation and
  coolability
• Ex-vessel debris formation and coolability
• Plus bringing research results into reactor
  applications
• Conclude on improved validated models and propose
  models for ASTEC

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SARNET2 Work-Packages (6 / 8)

• WP6 MCCI (MCCI)
• Major motivation Provide new data and understand
  corium-concrete interaction by using innovative
  approaches to address more prototypical phenomena
• Project designed to ensure complementarity with
  ongoing OECD/MCCI project
• Project planned to study
• Effect of concrete nature on 2-D ablation
  profiles
• Role of metallic layer in MCCI
• Efficiency of water cooling to terminate the
  ablation of concrete
• Proposed research regrouping experiments both
  with simulant and prototypic materials in order
• to determine which phenomena cause the observed
  effect of concrete composition on ablation shape
• to assess their influence at reactor scale
• Data to be acquired on corium - concrete phase
  diagrams
• Transfer the RD results to reactor scale and
  propose models for ASTEC

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SARNET2 Work-Packages (7 / 8)

• WP7 Containment (CONT)
• Dedicated to 2 highly energetic phenomena that
  may threaten containment integrity
• Steam explosion
• Hydrogen combustion
• Main uncertainties for ex-vessel steam explosion
• Level of void in the pre-mixing phase
• Role of material properties on explosion energy
• For hydrogen mixing and combustion, study of
• Thermal-hydraulics including hydrogen
  distribution
• Different combustion regimes (including DDT and
  combustion during DCH)
• Their impact on containment structures and
  measures to prevent combustion processes or at
  least mitigate consequences
• Bringing research results into reactor
  applications
• Elaboration of a generic containment model
  allowing analyses with lumped-parameter or CFD
  codes and recommendations for ASTEC

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SARNET2 Work-Packages (8 / 8)

• WP8 Source Term (ST)
• Aims at reducing uncertainties in calculating
  potential radioactive release in the environment
  especially for iodine and ruthenium
• Impact of oxidising conditions
• FP release from HBU and MOX fuels, competition
  between cladding and fuel oxidation, impact on FP
  release, prototypic air/steam mixtures
• Ru transport in RCS, behaviour of Ru oxides
  including reactions with surfaces and other FPs
• Ru behaviour in containment, possible conversion
  of Ru oxides aerosols to volatile species,
  potential revolatilisation from liquid phase
• Iodine
• Transport in RCS including chemical kinetics, re
  vaporisation, compilation of data on iodine
  spiking, SGTR
• Behaviour in containment, role of painted
  surfaces, radiolytic destruction of gaseous
  iodine, binding on materials in sump, effect of
  PARs
• Bringing research results into reactor
  applications integral plant scenario
  calculations, benchmarking, data book maintenance
  (iodine) and development (ruthenium), critical
  assessment of SAMGs, proposals of models for
  ASTEC

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Thank-you for your attention.

• Conclusions
• SARNET2 is now in the final negotiation phase
  with the EC.
• Hopefully, the project should start very early in
  2009 for a four year duration.
• Besides the scientific objectives, the
  integration and dissemination aspects, one major
  objective is the long term self-sustainability of
  the network through the creation of a legal
  entity.

AcknowledgmentsThe authors wish to thank the
European Commission and its representative, Mr
Michel Hugon, for supporting this SARNET2 Project
in the 7th FP. They also thank all the persons
who took part in the elaboration of the SARNET2
Project, too numerous to be quoted, for their
strong and efficient involvement.