Final Progress Report PLINIUS FP6 - CORDIS · Final Progress Report PLINIUS FP6 ... Project coordinator: Christophe JOURNEAU Project website: Project period: from 1/11/2006 to 31

Final Progress Report

PLINIUS FP6

Transnational Access to the Prototypic Corium Platform PLINIUS

Transnational Access

implemented as

Specific Support Action

Contract number: FP6-036403

Project coordinator: Christophe JOURNEAU

Project website: www.plinius.eu

Project period: from 1/11/2006 to 31/10/2010

Project funded by the EURATOM 6th Framework Programme

PLINIUS FP6 FINAL REPORT

FP6 Research Infrastructures 2 Contract Number FP6-036403 Transnational Access Final Report

A. ACTIVITY REPORT

Table of contents

1. Summary of the activities and major achievements ....................................................3 2. Management overview ..............................................................................................3 3. Description of the publicity concerning the new opportunities for access.................3 4. Description of the selection procedure ......................................................................6 5. Transnational Access activity ....................................................................................7

5.1 COLIMA CA-U4 7 5.2 VULCANO VB-U7 26 5.3 VITI experiments for KTH 36

6. Scientific output of the users at the facility .............................................................52 7. User meetings ..........................................................................................................53

ANNEXES

Annex 1 - Composition of the Users Selection Panel................................................................ 55 Annex 2 - List of User-Projects .........................................................................................................56 Annex 3 - List of Users........................................................................................................................57 Annex 4 - List of publications .............................................................................................................58 Annex 5 – List of Workshop Participants1.........................................................................................59


FP6 EURATOM 3 Contract Number FP6-036403 Transnational Access Final Report

A. Progress report A.1. Summary of the activities and major achievements Within the PLINIUS FP6 Transnational Access project, 3 experiments on the PLINIUS corium platform have been performed for and with user groups from Italy, Finland and Sweden. These experiments have been selected after open calls for papers and selection by an International Panel. A COLIMA experiment has been devoted to the fabrication of a prototypic aerosol cloud and the analysis of its retention through a concrete crack. It showed a significant retention especially for particles above 0.7 µm. A VULCANO experiment has studied the interaction of molten corium with the Olkiluoto 3 ferrosiliceous concrete. It showed an anisotropic ablation pattern similar to that of classical siliceous concretes. Finally, a series of VITI experiments have been conducted to provide density and surface tension data for the oxidic melts used by KTH in the DEFOR debris bed formation experiments. A.2. Management overview

The main management task in this project was linked to the preparation, publication and maintenance of the www.plinius.eu website and other publicity actions, the selection panel operation and the relations with the user groups.

A European web address (.eu) has been obtained for the PLINIUS European corium platform. Administrative burden delayed the internal publication authorization for this site which was finally open in March 2007.

The PLINIUS FP6 project has been presented at the several SARNET Annual Topical Review Meetings and to SNE-TP General Assemblies, as a way to inform the European partners of the possibility of free accesses to the PLINIUS facilities.

At the end of the PLINIUS FP6 contract, a joint user meeting has been organized with the LACOMECO Transnational Access project run by KIT.

A.3. Description of the publicity concerning the new opportunities for access

The www.plinius.eu website (Figure 1 and Figure 2) is the major way of publicizing the opportunities for access to research teams throughout Europe. On average, more than 200 computers have been connected each month to the website, according to our website administration tool.

Publicity on PLINIUS has been given at the ERMSAR and FISA conference, at SARNET and SNE-TP meetings, at nuclear engineering conferences. A leaflet (see Figure 3) has been distributed in these occasions and during discussions with potential users. This leaflet has been updated for each of the 3 calls for proposals



Figure 1: Front page of the www.plinius.eu website

Figure 2: webpage describing the PLINIUS platform facilities



Commissariat à l’Energie AtomiqueDirection de l’Energie NucléaireSevere Accident experimental LaboratoryCEA / CadaracheF13108 St Paul lez Durance

EU-sponsored*Free Transnational Access

to the PLINIUS Corium Platform

Only individual researchers or Research teams (Company, university, research lab,....) conducting their research in the Member States (except France) and the Associated States will be eligible to benefit to access to PLINIUS. Research teams must be entitled to disseminate or arrange dissemination of (e.g. through open publication) of the knowledge they have generated under the access to the PLINIUS infrastructure. An exception may be made in the case of 1st time access by a Small or Medium Enterprise.

These access grants are offered either for students (Master or PhD thesis, post-docs,…) or for more experienced scientists and engineers working on severe accidents or any other field for which access to our platform would be fruitful.

European Union Member States (except France )

Associated States (Nuclear Fusion):

ICELAND, LIECHTENSTEIN, NORWAY, SWITZERLAND

Access for users from other countries could be negotiated with CEA on a

bilateral basis

The PLINIUS platform is located at Cadarache in Southern France

•70 km North East from Marseille

•70 km from Marseille-Provence International Airport

•40 km from Aix en Provence at the confluent of Durance and Verdon rivers

CEA / Cadarache hosts experimental reactors, specialized laboratories, workshops and experimental halls for nuclear energy research. 450 buildings are devoted to R&D.

Cadarache is the largest CEA site outside Paris region, both in term of staff (5000 persons, mainly researchers, engineers and technicians) and of budget (380 M€).

For more information contact Christophe JOURNEAU E-mail : [email protected]://www.plinius.eu

Next calls for proposals deadline: March 2008

Cadarache

*EURATOM FP6 Contract

Do you want to perform free of charge

severe-accident experiments with prototypic corium

at CEA Cadarache (France)?

Access for visiting scientists from EU (except France) and Associated Countries

The EU will pay all facility costs + travel and expenses. You pay only your salary(ies) .

•Submission of Proposals by potential visitors

•Selection by International Panel

•Visit by 1-3 scientist(s) during ~1 month for the performance of experiment(s) with our scientific and technical team.

•You may bring specific apparatus to install in our facility.

•Visitors must disseminate results in the open literature.

PLINIUS is CEA experimental platform for prototypic corium. It is staffed with an experienced scientific and technical team.

Access to the following prototypic corium facilities will be offered.Prototypic corium = high temperature melts with depleted UO2

VULCANOVULCANO•Transferred arc plasma torch furnace•200 kW •35-70 kg of molten corium up to 3000°C

•Crucible tests with induction sustained heating

•Spreading tests

•Molten Core Concrete Interaction ….

COLIMACOLIMA•Induction heating (150 kW) •Few kg of corium•1.5 m3 enclosure ( 5bars, 150°C) •Temperature controlled walls

• Material interactions• Corium Physical Properties• Aerosols

VITIVITI•Viscosity & Surface Tension of molten corium •Aerodynamic levitation technique•Induction heating of droplet (few millilitres)•Furnace for 1 fuel pellet

Droplet at rest Compressed droplet

KROTOSKROTOS•Fuel Coolant Interaction (steam explosion) facility

•Electric Resistance heating of 4.5 kg corium•Release in water filled test tube.

Figure 3: The PLINIUS FP6 Leaflet (for the 2nd Call)



A.4. Description of the selection procedure The proposals for experiments from potential transnational users is assessed on the following criteria:

• Safety of the proposed experiment;

• Scientific and technical interest;

• Compliance with the interests of the Community;

• Relevance to end users;

• Technical Feasibility; • Fluency of the visitors in languages spoken by the experimental team (French, English,

Italian). • Priority is given to user groups who:

• have not previously used the infrastructure

• are working in countries where no such research infrastructure exists. The choice is made by the PLINIUS user group selection panel. Annex 1 lists the members of the user selection panel. Mrs Ilona Lindholm from VTT had to withdraw from the 2nd Selection Panel since a proposal from VTT was studied. Mrs Michel Auglaire, who participates to the SARNET Governing Board has been nominated by SARNET to replace her for this selection and serves as a link between these two projects. To prevent gender bias in this selection process, experts from both genders are thus contributing to the selection panel. Unfortunately no female researcher sent us a proposal for access.

The choice of the experiment is independent of the other national or international programmes conducted on the PLINIUS platform. It is only made according to the above-mentioned criteria. Nevertheless, the SARNET Severe Accident Research Priorities list is an effective tool for ranking the relevance to end-users.



A.5. Transnational Access activity Three transnational accesses have been performed. The first one (in November 2008) is related to a COLIMA test in which prototypic aerosols will pass through a prototypic concrete crack in order to validate the retention models. The second one (in October 2009), is related to the interaction of corium with EPR reactor pit sacrificial concrete in the VULCANO facility. The third and last one (in September-October 2010) is dedicated to the measurement of densities and surface tensions of the simulant melts used in the DEFOR facility in Sweden.

A.5.1 COLIMA CA-U4

A.5.1.1 Description of the COLIMA CA-U4 test setup

Figure 4: A view of the COLIMA facility in which prototypic aerosols were generated Under severe accident conditions, a fraction of in-containment gases and aerosol particles could escape containment through cracks and/or failed seals, even if a catastrophic containment failure does not occur. Traditional safety analyses assumed that the aerosol release rates are identical to the gas leak rates, even if narrow leak paths can trap airborne particles significantly. This conservative assumption is far from reality: a certain fraction of particles is expected to get removed from the carrier gas onto the bounding walls. Nevertheless, as any particle filtration would mean a less conservative source term estimate, a research program was set up within SARNET aimed essentially at: developing new theoretical models that overcome shortcomings of previous works in the open literature and validating them against available experimental data. This target has required to design and conduct experimental activities intended to be as representative as possible to anticipated scenarios. The experimental campaign is being conducted at the COLIMA facility (Figure 4). The aerosols will be produced from a piece of corium heated up to 2000-3000 K thanks to



exothermal thermitic reaction (process developed1 thanks to the EURATOM Intra European Fellowship No. 511307 “Corium Thermite”). The cracked sample (Figure 5), made of representative limestone concrete prepared and cracked at Cesi Ricerca (now RSE) (Figure 6), has been accommodated to the COLIMA facility with 4 0.5-mm Teflon packing pieces separating the two concrete halves.

Figure 5: Cracked concrete sample and sample holder, used in the first pre-test.

Figure 6: Cracking of the concrete sample at CESI Ricerca (now RSE)

1 K. Mwamba, P. Piluso, D. Eyriès, C. Journeau, Self-Propagating High –Temperature Synthesis of a Nuclear Reactor Core Melt for Safety Experiments, Int. J. Self-Propagat. High-Temp. Synthesis, 15(4): 284-296, 2006.



The Concrete sample has been placed in a thermally insulated aerosol line (Figure 7) which can be preheated. Aerosols are sampled (Figure 8) up and down stream from the concrete sample. They are collected and sized thanks to two 7-stage impactors (Figure 9). In such a device, aerosols larger than a cut-off size impact a collector while the smaller ones can follow the gas flow and reach the lower stage with a smaller cut-off size (Figure 10). The gas flow rate is then measured and directed to the PLINIUS platform chimney (with high efficiency filters).

Figure 7: The aerosol test line

Figure 8: View inside the piping showing a thermocouple and the piping for the impactor.

Flow line from COLIMA

Concrete sample

Line to upstream impactor

Downstream impactor

To flowmeter and filtered

exhaust



Figure 9: View of the two 7-stage impactors stacks and of their dedicated pumps.

Figure 10: Principle of impaction: one of the 100-400 orifices at one stage.



A.5.1.2 Description of the test and of its main results The COLIMA CA-U4 test has been performed on November 28, 2008 in the presence of two users from CESI Ricerca (now RSE),F. Parozzi & F. Polidoro (Figure 11).

Figure 11: Flavio Parozzi (yellow coat) from CESI Ricerca (now RSE) and Patricia Correggio (CEA) in front of the PC-operated controls during COLIMA CA-U4 test. About 2 kg of a mixture of uranium and zirconium oxides, steel, concrete degradation products and fission product elements (Table I) have been heated above 2000°C and melted, thanks to an uranothermic process (exothermal oxido-reduction of U3O8, CrO3 et Zr). It generated a prototypic aerosol cloud (having the same physicochemistry as during an accident scenario but a different isotopic composition). These aerosols have been transported to the cracked concrete test section (provided by CESI Ricerca (now RSE)). They were sampled upstream and downstream of the concrete crack. The test procedure is the following:

• Load preparation • Pre-heating of aerosol transport tubes: 110°C • COLIMA set to 1 bar rel. (N2) • GILOTHERM heating ( of COLIMA walls) : 60°C • Stabilization of flow rate: 440 L/min • Ignition of the urano-thermitic load • MCCI-aerosols formation, release and transport to impactors and concrete test section

There has been no significant changes in temperature and pressure around ignition time. Both impactor sampling lines used a 1 cfm (28.3 L/min) isokinetic pump. In the upstream line, a diffuser is used so that the 2 bar (absolute) flow is divided in two 28.3 L/min flows at 1 bar (absolute). The downstream sampling line can be assumed at atmospheric pressure.



Before the test, all the impactor collectors had been heated above 100°C (to release humidity) and weighed. After the test, they have been weighed (Figure 12) and their mass increase has been determined.

Compound (reactant) Products Mass (g)

U3O8 UO2 1224 (1178)

Zr ZrO2 369 (498)

CrO3 Cr 115 (60)

Fe2O3 Fe 92 (65)

CaO 73

SiO2 80

MgO 27

SrO 1.3

Y2O3 0.7

MoO2 4.2

RuO2 3.1

Rh2O3 0.6

TeO2 0.6

I2O5 0.3

CsOH (hydrated) 3.92

BaO 1.8

CeO2•ZrO2 6.5

Pr2O3 1.3

Nd2O3 4.0

Total 2009.6 Table I: Corium Load composition

2 Corresponding to 2.9 g of Cs2O



Figure 12: Impactor collector 1E (Upstream 5.8-9µm aerosols) being weighed. Black spots on the weighed white collector are impacted aerosols.

Figure 13: Upstream impactor collected masses

Figure 13 presents the collected masses for each stages of the impactor. The indicated diameters are aerodynamic diameters, i.e. the diameter of spherical particles of density 1.0 having the same inertial behaviour than the aerosols. From these raw data, a size distribution can be estimated (Figure 14). The Aerodynamic Mass Median Diameter (AMMD) is around 1 µm. A best fit with a log-normal law (Figure 14) gives an AMMD of 0.97 µm with a logarithmic standard deviation of 0.72.

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5.8-9µm



Upstream aerosol size distribution

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9.57.45.2542.71.60.90.550.2

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Figure 14: Upstream aerosol aerodynamic size distribution.

Cumulative Mass Distribution

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Figure 15: Comparison of upstream cumulative size distribution with a log-normal law (AMMD 0.97 µm, σ = 0.72) A total of about 270 mg of aerosols was directed to the cracked sample, taking into account of the ratio of gas flows. If one considers that the aerosol cloud lasted 5-10 minutes, this gives, for an entering flow3 of 400+28 L/min, an upstream aerosol concentration of 0.05-0.1 g/m3. Very few aerosols have been collected at the downstream impactors (Figure 16), indicating an important retention. Downstream, the only visible aerosols have been found in the 0.4-0.7µm bin (Figure 17) and are much less than upstream.

3 Sum of the measured flow and of the flow to the downstream impactors.



Figure 16: Downstream (left) and upstream (right) collectors for stage 2 (4.7-5.8 µm)

Figure 17: Downstream (left) and upstream (right) collectors for stage 7 (0.4-0.7 µm)

CA-U4

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Figure 18: Upstream and downstream deposited aerosol masses



Figure 18 presents the distribution of aerosol masses at the up and downstream of the crack, with errors bars corresponding to the 0.4 µg weighing uncertainties. It appears that the downstream deposits are below the uncertainty threshold, but that retention is larger than a factor of 10 at stage 7 (0.4-0.7 µm) for which some particles escaped the crack, and much larger for the larger sizes. Post test analyses of the impactor samples The impactor collector material is mainly made of SiO2 fibres with 6% of barium and other impurities such as Zn, Al, Ca, K (Figure 19). Therefore, it will not be possible to measure precisely the silica and barium deposits.

Figure 19: SEM micrograph of a clean impactor collector (average composition: 28 wt% Si, 6% Ba, 4% Zn, 3% Al, 3% K, 1% Ca, 54 wt% O)

Figure 20: SEM micrograph of the 7th stage (0.4-0.7 µm) upstream collector (Left: View of the deposits in front of an impactor jet. Right: Zoom on an agglometrate) For the smallest aerosol size (0.4-0.7µm stage 7), there are typically (after eliminating the collector fibre composition) in Figure 20 Spectrum 2: 18 wt% Cs, 5% Te, 3% I, 3% Cr, 2% Fe. It must be noted that iodine has not been observed in the other stages corresponding to larger particles. For stage 6 (0.7-1.1 µm) to 4 (2.1-3.3 µm), Cs, Te, Cr and Fe have also



been observed with typical ratios of 3-4:1.2:1:1:1. Some uranium (2-3 wt%) have been observed in some of the deposits at stage 7. In the first stages (larger particles), there were only few particles (see Figure 18 and Figure 21) preventing a fully quantitative analysis. Caesium is the major component at this stage, followed by magnesium, chromium and iron.

Figure 21: SEM of the Stage 2 (4.7-5.8 µm) upstream impactor On the downstream impactor, only stage 7 (0.4-0.7 µm) presented some deposit (Figure 22). Typical composition of the agglomerated deposits include Fe, Cr but also fission product prototypes: caesium and to a smaller extend molybdenum and cadmium.

Figure 22: SEM micrograph of Stage 7 (0.4-0.7 µm) downstream collector A.5.1.3 Post Test Examination of the concrete crack After test, the concrete sample has been dismounted from the sample holder. No aerosol deposit was observed on the concrete faces, even near the crack upstream inlet (Figure 23). The sample sealing are visible on its periphery.



Figure 23: Upstream (left) and downstream faces of the post-test concrete sample The sealing has then been cut and the two halves have been separated. Figure 24 shows that there has been an intense aerosol deposition (in black) in the first 5 cm of the crack sides, and that there has been almost no deposit after 20 cm. In the 5-20 cm range, some preferred flow path traces are visible. The aerosol deposition follows the peaks and through of the cracked surface (Figure 25).

Figure 24: Post-test view of the two sides of the concrete crack The arrow indicates the direction of flow



Figure 25: Left: View from upstream of one of the concrete halves. Right: Zoomed photograph showing the effect of crack tortuosity on deposits The Teflon 0.5 mm spacer is visible (small white square); The arrow indicates the direction of flow The sample has been divided in 5-cm zones and the aerosols have been wiped from one of the halves and collected. Table II presents the collected masses for the three sampling zones (zones 10-15 and 15-20 cm have been grouped due to the small amount of aerosol). The total collected mass is of about 300 mg.

Zone Collected mass Mass fraction 0-5 cm 210 mg 70% 5-10 cm 68 mg 23% 10-20 cm 21 mg 7%

Table II : collected aerosol masses on one half concrete-section These numbers are not fully consistent with the masses estimated from impactors, maybe because of the mixing of aerosol with some concrete particles during collection, so it is recommended to consider mainly relative fractions. The powdery deposits have been transferred to the analysis laboratory. Figure 26 presents the Scattered Electron Microscope (SEM) micrograph of some of the powders collected in the first 5 centimetres of the crack. Numerous elements have been measured by Energy Dispersive Spectroscopy (EDS) including caesium, tellurium, and uranium (chlorine is an artefact of the preparation process). Figure 27 shows some individual particles. The large white particle (Spectrum 1 and 9) is made of (U, Zr)O2. Spectrum 3 represents a particle of concrete decomposition products (Mg, Ca, Si)Ox with some chromium (4 wt%) and caesium (2 wt%). In spectrum 5, there are 18 wt% Te and 12 wt% Te with some iron and chromium oxides and concrete oxides. Figure 28 presents some of the deposits that was collected between 5 and 10 cm from the crack inlet. Spectrum 4 indicated the presence of Cs, O (and Cl artefact) and it seems that this particle measuring about 2x4 µm was caesium oxide (or hydroxide, since H cannot be detected by EDS). Caesium oxide is now a major constituent of the remaining particles (~60% of the metallic elements) in the 5-10 cm zone.



In the last part of the crack (more than 10 cm away from the inlet), the deposits (Figure 29) were mainly made of iron and uranium (sometimes with some zirconium).

Figure 26: Macrograph (top) SEM micrograph (middle) and EDS Spectrum (bottom) of powder sample coming from the concrete crack first 5 centimetres



Figure 27: Close-up view on some particles deposited in the first 5 cm of the crack

Figure 28: SEM micrograph of particles collected between 5 and 10 cm from crack inlet. Spectrum 4 points to a caesium oxide aerosol.



Figure 29: SEM macrocraph of samples collected on the concrete crack between 10 and 20 cm from inlet (23 wt % Fe, 13% Si, 9 % U, 2.5% Zr, 2.5% Ca, 43% O,…)

Mg Si Ca Cr Fe Te Cs Ti U B1(0 - 5cm) 10% 17% 9% 19% 15% 12% 18% 0% 0% B2(5 - 10cm) 5% 11% 2% 12% 9% 6% 56% 0% 0% B3(10 - 15cm) 3% 27% 5% 0% 45% 0% 0% 2% 19% Table III: Average mass fraction in the samples collected from the concrete cracks (normalized to 100% without chlorine and oxygen). Table III compares the average compositions from the three samples. It appears that Cs and Te are mainly deposited in the first 10 cm (caesium representing more than half of the deposits in the 5-10 cm zone). In proportion, the fraction of uranium oxide aerosol is negligible in the first 10 cm deposits but becomes significant (19%) in the remainder (since most off the other aerosols have been deposited, except iron). It is difficult to assess in which proportion the measured Si, Mg and Ca are due to concrete decomposition product aerosols and to debris from the concrete surface. In conclusion, it must be noted that some radioelements such as uranium (found in the B3 sample) and caesium (found in the downstream stage 7 collector) are within the least deposited particles. A.5.1.4 Post Test Calculations by RSE F. Parozzi and S. Morandi(RSE, formerly CESI Ricerca) have performed a preliminary sensitivity analysis with ECART-code. It must be stressed that the transport time in the crack is of the order of 4 ms. The observed retention can be explained only assuming that adhesive forces strongly prevail the lift forces. Almost all the retained particles are removed by centrifugal settling in the crack tortuosity (average path curvature set to 1 cm). The retention



cut-off has been estimated, in this preliminary run around 0.1 µm, giving the right order of magnitude (Figure 30).

Figure 30: Computed retention factor vs. particle diameter. Some post-test calculations4 have been then performed at RSE with the code ECART5. Crack tortuosity (Figure 31) is mainly modelled in ECART by multiplying crack length by π/2 and taking into account the crack curvature radius in the centrifugal deposition model.

Figure 31: Schematic representation of a tortuous crack A satisfactory fit between the code and the experiment has been found. Centrifugal deposition in the tortuous crack is the major cause of deposit.

4 F. Parozzi, S. Morandi, Analisi del test sperimentale COLIMA per la messa a punto di un modello di retenzione degli aerosol nelle fissure di calcestruzzo in caso di incidente nucleare grave, RSE Report 10000909 (2010). 5 F. Parozzi, S. Chatzidakis, T. Gelain, G. Nahas, W. Plimecocq, J. Vendel, L.E. Herranz, E. Hinnis, C. Housiadas, C. Journeau, P. Piluso, E. Malgarida, Investigations on Aerosol transport in Containment cracks, Int. Conf. Nuclear Energy New Europe, Bled, Slovenia, 5-8/9/2005.



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Figure 32: Effect of curvature radius (in m) on deposition computed by ECART Figure 32 presents the effect of the crack curvature radius on the deposits. Curvature radii between 20 and 30 mm give the best agreement between experimental and numerical results. It must be stressed that the maximum size of the concrete aggregates (16 mm) has the same order of magnitude as this curvature radius. Figure 33 presents the effect of the aerosol density - represented here as a porosity relative to an aerosol density that had been estimated at the corium melt density (7350 kg/m3), whereas chemical analyses indicate that aerosols are mainly made of lighter elements - . Retention after 10 cm seems to be well modelled assuming a density of 5500 kg/m3, while for the first 5 cm, heavier particles seem to be needed. It must be reminded that the deposits (Table III) in the 5-10 cm range are mainly made of caesium oxide (density 4500 kg/m3) while there is a larger fraction of iron and chromium (densities of 7900 and 7200 kg/m3) in the deposits found in the first 5 cm

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A.5.1.5. Synthesis on CA-U4 Even if the duration of aerosol generation was shorter than planned, the test was successful and confirmed the intense aerosol deposition in a representative crack path. Retention of about 95% was achieved, mainly in the first 10 cm of the crack. It must nevertheless be noted that all chemical species and particle diameters are not retained in the same way: only the smallest particles (below 0.7 µm of aerodynamic diameter) were not totally deposited (within experimental uncertainties). The main elements of the undeposited aerosols are steel elements (Fe, Cr), but cesium, and to a slightly lesser extent molybdenum and cadmium have also been transported through the crack. The main removal mechanism appears to be centrifugal deposition because of the crack tortuosity (the best results are obtained with a curvature radius of the order of the maximum aggregate sieve size). This has been obtained thanks to an improvement of ECART code, that now includes the centrifugal force in the resuspension model (i.e. accounting centrifugal force in the calculation of the adhesive forces). Only one test is not sufficient to establish the range of experimental uncertainties and validate or adjust the code models. It would therefore be useful to conduct experiments with different conditions in terms of crack thickness and flowrate. Future studies should be addressed towards two aspects: → Limits of the current resuspension model (the centrifuge effect is not active if the particles are deposited, and saltation can occur) → Update/adjustment of the deposition correlations (responsible for the predicted retention)



A.5.2 VULCANO VB-U7 On October 14 and 15th, 2009 was conducted at CEA Cadarache the VULCANO VB-U7 test. It is aimed at observing the interaction between an oxidic corium6 and the Olkiluoto-3 EPR reactor-pit concrete. This ferro-siliceous concrete (FESICO) is made of iron oxide (hematite) and silica aggregates. Since it differs from concretes previously applied into reactor pits, it was wanted to verify that it would behave, during a postulated severe accident, as standard concretes. Tuomo Sevòn, our scientific user from VTT attended to this test as well as Manfred Fischer from AREVA NP Erlangen (Figure 34). He had previously performed pre-test calculations of the VB-U7 experiment.

Figure 34: VULCANO experimental team in the control room during VB-U7, with the participation of T. Sevon (left, 1st row) and M. Fischer (right, 2nd

row)

A.5.2.1 Description of the facility and test section The test facility is identical to that of the oxidic corium VULCANO MCCI (Molten Core Concrete Interaction) tests7 with the VULCANO transferred plasma arc furnace and a concrete test section.

6 Corium is the molten mixture of oxidized fuel elements and structural materials that would form during a postulated nuclear reactor severe accident. 7 Journeau, C. Piluso, P. Haquet, J.F. Brissonneau, L. Aubert-Saldo, V. 2008, “Behaviour of

nuclear reactor pit concretes under severe accident conditions”, Proc. CONSEC ’07, Concrete under Severe Conditions, Tours, France (2007).



The test section has the same dimensions as the former ones: 600 x 300 x 400 mm concrete block in which a hemicylindrical cavity (300 mm diameter, 250 mm depth) is present. This block is inserted inside a rectangular inductor as shown in Figure 35.

Figure 35: Test section (top view) The inductor is surrounded by cellular concrete and the 50-mm gap is filled by silica powder (as a protection against hypotethical leaks). On the crucible open face, a 12-mm thick porous zirconia plate is inserted, preventing direct contact between the pool and the copper coils. It provides a thermal barrier limiting the crust thickness. As for previous tests, the inductor is made of 14 copper coils (25*10 mm) with 5 mm spacing. The four active8 coils are positioned in front of the oxidic pool (Figure 36). There are (from top to bottom): three neutral coils, 4 active coils, seven neutral coils. This optimises the electromagnetic field in the crucible. All the coils are water cooled. Each group of coils (upper neutral, active, lower neutral, sole) has its own independent cooling system with temperature and flow rate measurement, so to have the necessary data for heat and electrical power balances. Generator and active coil voltage, current and frequency are monitored throughout the test.

8 Connected to the HF generator

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m



Inducteur : 14 barres de 25 mm espacées de 5 mm

BETON

INDUCTEUR

SIPOREX

700 mm

BETON

150

mm

25

0 m

m

450

mm

300 mm 150 50 mm

Clarinette

Sole

Figure 36: Test section (front view) VTT has provided CEA with raw materials (mixture of sand, gravel and cement + plastifier) to prepare 1 t of EPR concrete. The concrete was made of almost the same materials that are used for the Olkiluoto 3 EPR sacrificial concrete in the reactor pit. The dry materials were obtained as a readymade mixture from the Olkiluoto construction site. The dry mixture included 46.63 % siliceous aggregates, 38 % iron ore (hematite) and 15 % cement by weight. The particle size distributions of both siliceous and hematite aggregates followed the standard sieve line B8 in DIN 1045-2.

Figure 37: Volumetric size distribution of the aggregates according to DIN1045-2 vs. sieve mesh (mm) EPR sacrificial concrete follows sieve line B8.



In addition, there were some additives and admixtures (silica fume, liquid plasticizer and polymer fibres to improve the concrete behaviour against spalling at high temperatures9). The amount of water used in mixing the concrete was 6.14 % of the mass of the dry mixture. After drying, the concrete had lost 2.4%. Samples from concrete made from a similar batch for HECLA-5 experiment has been analyzed at VTT (Sevon et al., 2009). Its composition is given by Table IV.

Compound Mass-%

SiO2 44.4

Fe2O3 32.1 CaO 9.8

CaCO3 3.04

Ca(OH)2 1.2

Al2O3 3.20

SO3 0.99

K2O 0.56 MgO 0.33 FeO 0.20

TiO2 0.17

Na2O 0.13 Ba 0.057 P 0.057 Sr 0.047 Cr 0.028 Mn 0.028 Cl 0.019 Zn 0.010

H2Ochem 1.68

H2Ofree 2.41 Sum 100.456

Table IV: Concrete composition (from HECLA-5 test)

Figure 38: VB-U7 Concrete test section Red colour is due to the presence of hematite aggregates in concrete

9 Schnuetgen, B. 2008. Preliminary Test Program Sacrificial Concrete Fe/Si/Pz 15/8 for the

Reactor Pit. Rev. A. 20080917. Areva NP. 22 p. (Technical report FSFE DC 0174.)



As for previous VULCANO MCCI tests, 129 type-K thermocouples (1.5 mm diameter) and 10 high-temperature type-C thermocouples have been installed in the test section (Figure 38) before concrete was poured, along three planes (azimuth 45, 90 and 135°). They are positioned to provide insight on the ablation front progression (Figure 39). 1-mm Nylon wires are used to position the thermocouples during concrete pour. Each type-K thermocouple is joined or glued to a Nylon wire. The hot junctions (measurement points) are positioned 12 mm towards the crucible axis from the wire, in order to reduce the heat transfer perturbations. In order to prevent the early failure of upper thermocouples due to the ablation of its cable, the TC cables of the upper TCs are connected by the top of the test section, while the lower TCs are connected through the bottom.

Figure 39: View of the thermocouples in the frame used to pour the test section concrete Seven video cameras and five pyrometers are typically used to monitor (Figue 40) the VULCANO furnace, the pool surface behaviour and the long term interaction.

Figure 40: View of the corium being poured in the concrete cavity, from 4 videocameras.



A.5.2.2 Description of the VB-U7 test Uranium containing prototypic oxide corium was molten in the VULCANO Plasma arc furnace and 53.8 kg were poured at a temperature of about 2200°C inside a cavity of the concrete test section. From our experience of previous tests, the expected corium composition is close to (in mass percentages): 4.3%SiO2 0.9%CaO 2.4%Fe2O3 34.7%ZrO2 54.5%UO2

According to a computation with GEMINI2 and NUCLEA_09_1, it has a solidus at 1460 K and a liquidus at 2610 K. Radiological decay heat has been simulated for 100 minutes using induction heating. Then the power was cut-off for 20 minutes, and restarted for another hour (Figure 41).

0

100

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300

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11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00

F (

kHz)

- Ig

éné

(A)

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géné

(kW

)U

géné

(V

) -

Uin

d (V

)

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500

1000

1500

2000

2500

3000

3500

4000

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(A)

1 2

Figure 41: Induction electrical parameters dark blue: frequency, purple: inductor current, red: generator power, light blue: generator voltage, brown: inductor voltage, green and orange: inductor current (2 different probes) According to the induction heating calibration, an average power of 25 kW has been provided to the pool throughout the test, although the power to the induction generator is of the order of 100 kW. Substracting the heat losses to the copper coil, the “useful induction power” – for concrete ablation and heating, plus free surface radiation – is on average of 17 kW. Tungsten-rhenium thermocouples measured the pool temperature throughout the test (Figure 42). The initial corium temperature was above 2250°C. When the pool reached the second circle of thermocouples, electrical perturbation appeared. At the cut-off, after 100 minutes, as at the end of the test, a temperature of 1550°C has been measured. About 20 minutes after restart, the thermocouples reached back the values they had before cut-off. At the end of the test, a temperature of about 1550°C was again measured.



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)

TCW1 TCW2 TCW3 TCW4

TCW5 TCW6 TCW7 TCW8

TCW9 TCW10

1890°C

2250°C

1550°C 1550°C

Figure 42: Type-C thermocouple readings yellow areas correspond to the heating periods. In-concrete thermocouples monitored the concrete ablation progression, which was mostly along the radial direction, as previously observed in tests with silica-rich concretes (Figure 43 and Figure 44).

Figure 43: Thermocouple at the 90° azimuth. Green clouds indicate the destroyed TCs and thus draw the ablation profile.

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Figure 44: temperature maps at the time of the cut-out (100 minutes after start) and electrical parameters. At 14:20, the ablation on azimuth 90° was too close to the concrete section rear and a leak occurred. More than 20 kg of corium have spread outside of the cavity (Figure 45). This had the most interesting consequence of enabling us to distinguish between the crusts (which remained in the test section) and the liquid pool, which spread out of the test section, leaving a large cavity (Figure 46). Samples from the different crust locations (Figure 47) have been taken and will soon be analyzed. Already, the fact that a large number of gravel was present in the solidified corium must be stressed. Corium spread samples have also been taken for material analyses.

n Figure 45: Left: View of the test section backside showing the corium leakage Right: One of the corium spreads.



Figure 46: View of the large cavity, after dismounting the zirconia plate and its crust

Figure 47: Corium crusts upper left: below the cavity ceiling upper right: free surface Lower left: lower crust lower right: lateral crust



T. Sevòn10 has compared the experimental data with calculations using the FinCCI correlations11. The correlations for lateral and axial heat transfer deduced from CCI-1, CCI-3 and CCI-5 experiments have been directly applied to VULCANO VB-U7. Sidewall ablation (Figure 48) is well predicted, showing that the correlation - established in CCI geometry with classical siliceous concretes – is applicable to ferro-siliceous concretes. For the axial ablation (Figure 49), there are only 5 experimental data points since the axial ablation was so small that only a few thermocouples were destroyed. The general match between calculation and experiment is nevertheless globally good.

Figure 48: Lateral ablation in VB-U7 (dots) vs. FinCCI calculation (red line)

Figure 49: Axial ablation in VB-U7 (dots) vs. FinCCI calculation (red line) Concerning the melt pool temperature ( Figure 50), there are only two measurements points in the absence of electromagnetic interferences (represented by black dots) and the fit is quite good. Nevetheless, the temperature readings in the first 10 minutes seem to be unperturbated (Figure 42), so it seems that FinCCI may underestimate the pool temperature, which is conservative with respect to spreading initial conditions.

10 T. Sevòn, A heat transfer analysis of CCI and VULCANO experiments, VTT Research Report VTT-R-00483-11 (2011). 11 T. Sevòn, A heat transfer analysis of the CCI experiments 1–3. Nuclear Engineering and Design, Vol. 238, p. 2377–2386 (2008).



Figure 50: Melt pool temperature estimation with FinCCI

A.5.2.3Summary on the VB-U7 test Although the material analyses are not available at the time of writing the following conclusions may be drawn:

The EPR ferro-siliceous concrete behaved like classical silica-rich concretes: anisotropic ablation by corium.

Even if relatively low temperatures have been recorded in the corium pool, an unplanned leak showed that the corium after MCCI has a good spreadability.

The current MCCI codes are able to reproduce satisfactorily the evolution of MCCI with EPR concrete, when the lateral to axial ablation anisotropy has been determined on other 2D tests.

A.5.3 VITI experiment for KTH

A.5.3.1 Introduction The DEFOR research program12 conducted in KTH, Sweden is focused on the investigation of the fragmentation, solidification and debris bed formation of simulant melts in water. The objective of the research is to provide reliable and representative experimental data on Fuel Coolant Interaction using water as coolant and some low temperature melt as corium simulant. One of the primary challenges of the DEFOR research program is to define an oxide melt that could be used as a simulant of corium in terms of:

• resulting particle size distribution,

• morphology of the crystallized samples, which depends on such thermophysical properties as density, surface tension and viscosity, thermal conductivity, coefficient of thermal expansion and mechanical strength.

It is also important that simulant material allows its processing at low temperatures (<1500 °C) applying conventional techniques and not excessively expensive materials.

12 12 Kudinov P., Karbojian A., Ma W., and Dinh T.-N. “The DEFOR-S Experimental Study of Debris Formation with Corium Simulant Materials,” Nuclear Technology, 170(1), April 2010, pp. 219-230.



The goal of the current research program was to perform the measurements of physical properties (density, surface tension and possibly viscosity) for a series of simulant binary oxide melts in order to verify if the chosen systems have similar properties to those of corium. The measurements have been realized in the VITI (Viscosity Temperature Installation) facility applying gas-film levitation for the access of Pavel Kudinov and Louis Tamilarasan. Due to the impossibility of prolonged sample levitation (which will be discussed further) only density and surface tension have been measured. However, a rough estimate of viscosity will be provided.

A.5.3.2 Principles of the gas-film levitation and its application for physical properties measurements

The principles of the gas-film levitation are shown in the Figure 51a. The positioning of a drop is performed on the thin gas-film, formed between the drop and the pressurized porous graphite diffuser. In order to obtain lateral stability of a levitated sample, the upper surface of the lower diffuser is concave. At least three thermophysical properties can be measured by gas-film levitation: density, surface tension and viscosity. The measurement of the first two is based on the analysis of the static drop contour and implies the application of the Axisymmetric Drop Shape Analysis (ADSA) 13. The measurement of the viscosity is based on the analysis of the drop relaxation process after the initial deformation by upper diffuser (see Figure 51b).

Figure 51: Principles of the gas film levitation (a) and viscosity measurement (b)

A.5.3.2.1 Density and surface tension measurements Measurement of density and surface tension is performed continuously and separately from the measurement of viscosity. The video record of the drop in levitation is obtained and synchronized with the temperature readings. The contours of a drop, corresponding to a series of temperatures, are extracted from the video and fitted with Yang-Laplace equation:

13 Hoorfar M., Neumann A. W. Recent progress in Axisymmetric Drop Shape Analysis

(ADSA) // Advances in Colloid and Interface Science. – 2006., 121. – P. 25-49

h=0.1mm

Gas-film

Upper diffuser

Sessile drop

Lower diffuser

Inert gas input

Holder

Inert gas input

Concave Lower diffuser

a b



sind

b c zds x

φ φ= + ⋅ − (1)

where ,x z are the coordinates of the drop contour with the origin at the drop apex (z axis is directed downwards), s is the length of the drop contour measured from the apex, b 2/R= is the curvature at the drop apex and c /gρ σ= ⋅ is the target parameter, ratio of gravity force to surface tension, φ is the angle between the tangent drawn to the drop contour and horizontal. As soon as the values of c and b are obtained, the estimation of surface tension and density are straightforward. Assuming the lower surface of the drop to be flat, the volume can be estimated numerically by integrating over the fitted theoretical contour s:

2( )s

V dπ= ⋅ ⋅∫ r i n r (2)

Where r is the radius vector to the drop contour, i is the unit vector of the abscissa and n is the normal to the drop contour. Since the lower part of a drop is hindered by the diffuser edge the computation of the volume here is based on the extrapolation of the drop contour by Laplace equation. This extrapolation is valid only if the drop bottom is fully melted. Next, knowing the drop mass, the density and surface tension can be easily calculated:

;l

v g

m c

ρρ σ ⋅= =

(3)

It should be noted ADSA does not allow separate measurement of density and surface tension, but provides density and parameter c of Laplace equation (ratio of density and surface tension). The direct values of parameter c are considered as the most accurate, since they are based only on the analysis of the visible part of a drop contour. Three remarks are important in view of the above description for the correct understanding of the methodology. First , the assumption that drop bottom is flat is not absolutely correct. It is always concaved and thus results in a certain overestimation of drop volume; however, applying sufficiently low sample masses, diffusers with low curvature of the levitation surface and reasonable gas-flow rates the corresponding uncertainty can be negligible. We apply a separate mathematical analysis of a drop in gas-film levitation to estimate the necessary experimental conditions that would provide the sufficient flatness of a drop bottom for correct volume estimation. This analysis is not provided here. Second, the diffuser edge hinders the lower part of a drop in levitation and thus this part is extrapolated using the Laplace equation in order to estimate the drop volume. The gas supplied into the lower diffuser to sustain the sample in levitation can lead to the cooling of its bottom and consequently can preserve the solid shape of the initial sample while its top is already melted. If the diameter of the remaining (not yet melted) solid crust at the bottom of the sample is higher than the corresponding equilibrium diameter of a drop levitation surface, a restriction will be imposed on the drop shape leading to a significant overestimation of its volume when extrapolating by Laplace equation. This problem can be solved only by sufficient overheating of a drop to ensure that none of its outer surfaces are solid. The apparent density and surface tension of such samples rises fast with temperature and thus can be distinguished. Third , if a drop in levitation encapsulates gas bubbles, computation of its volume would be wrong and due to bubble expansion with temperature rise, the thermal expansion coefficient will be overestimated. The solution is to overheat the sample allowing the gas bubbles to break through the drop surface and leave the sample. Commonly the gas bubbles, if exist, segregate at the drop apex and can be distinguished as moving knolls on the surface.

A.5.3.2.2 Viscosity measurements Viscosity measurement is based on the analysis of the kinetics of drop relaxation. The time evolution of the drop apex after the release of deformation stress is to be obtained from the



video. Depending on the Ohnesorge number of a drop ( / eRη ρσΩ = ) two types of

relaxation can be established: a-periodic or periodic. In the first case the drop slowly establishes its steady shape following an exponential dependence. In the second case the drop undergoes a series of damped oscillations. The viscosity can be estimated on the basis of Chandrasekhar14 or Perez15 models. The former considers the relaxation of a spherical drop in the absence of gravity, while the latter considers a drop to be ellipse-like with fixed south pole and takes into account the gravity force in the analysis of the relaxation. The Perez approach is recommended. In order to facilitate the calculations of viscosity with Perez model, it has been fitted as a correction to the corresponding Chandrasekhar solution: a-periodic mode ( 0.767Ω > )

2

6 5 4

3 2

40

3838

15

0.00370734 0.03579170 0.06255007

0.07334942 0.26415732 0.02960584

0 2

Ch aa

Per Cha a a

a

R

C

C f f f

f f f

f

σ τη

η η

⋅= ⋅

= ⋅ ⋅

= − + − −

− + −< ≤

(4) (5) (6)

periodic mode ( 0.767Ω < )

2

2

3 2

1

5

10

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0.0679 0.1949 0.1277 1.0127

0 2

Chp

p

Per Chp p p

p

R

C

C f f f

f

ρητ

η η

⋅= ⋅

= ⋅ ⋅

= − + +

< ≤

(7) (8) (9)

where index a stands for a-periodic and p for periodic modes, ,

Cha pη is viscosity according to

Chandrasekhar model, ,Pera pη is viscosity according to Perez model, ,a pC is a polynomial fit of

Perez solutions, /s cf R l= is the shape factor (sR is the radius of equivalent sphere (equal

volume); /c l ll gσ ρ= is capillary length ), ,a pτ are relaxation and damping times

respectively. The last two are estimated by fitting the experimental evolution of the drop apex with one of the following equations: a-periodic mode

( ) expoa

h h hτττ

= + ∆ ⋅ −

(10)

periodic mode

( ) exp cos( )op

h h h wττ τ ϕτ

= + ∆ ⋅ − ⋅ +

(11)

14 Chandrasekhar S. Hydrodynamic and hydromagnetic stability // Clarendon Press, Oxford, 1961. – 706 P. 15 M. Perez, Ph.D. thesis (Institut National des Sciences appliquees de Lyon, 2000)



As it was already pointed out, no viscosity measurements have been performed but this short review is necessary for the following later discussion.

A.5.3.3 Studied materials Initially four compositions of the binary oxide system WO3 – Bi2O3 have been considered for the investigation:

1. 50 mol.% Bi2O3 – 50 mol.% WO3 2. 29 mol.% Bi2O3 – 71 mol.% WO3 3. 27 mol.% Bi2O3 – 73 mol.% WO3 4. 22 mol.% Bi2O3 – 78 mol.% WO3

Later, the above list was extended to include additionally two systems: 5. 26 mol.% ZrO2 – 74 mol.% WO3 6. 25 mol.% CaO – 75 mol.% WO3

Several other compositions and systems have been considered but unfortunately they could not be studied due to the limited time-frame of the project and number of available lower diffusers for levitation. Hereafter a simplified notation for the composition of the samples is used. Since all of the above systems contain WO3 as a major component it was decided to exclude it from the notations and apply only the first letter of the secondary component followed by a number that specifies its mole fraction. For example, the sample containing 50 mol.% Bi2O3 – 50 mol.% WO3 is designated as B50. In the following table we summarize the melts compositions, solidus and liquidus temperatures. The corresponding phase diagrams with superimposed temperature intervals of measured melts properties can be found in Figure 52 to Figure 54.

Temperature, °C # Composition Notation Crystallization field

Solidus Liquidus 1 50 mol.% Bi2O3 – 50 mol.% WO3 B50 Compound: Bi2WO6 1080 2 29 mol.% Bi2O3 – 71 mol.% WO3 B29 Bi2W2O9 870 880

3 27 mol.% Bi2O3 – 73 mol.% WO3 B27 Eutectic: WO3 - Bi2W2O9

870

4 22 mol.% Bi2O3 – 78 mol.% WO3 B22 WO3 870 1020

5 26 mol.% ZrO2 – 74 mol.% WO3 Z26 Eutectic: ZrW2O8-WO3

1231

6 25 mol.% CaO – 75 mol.% WO3 C25 Eutectic: CaWO4-WO3

1135

Table 5: Studied compositions The densities in solid state at room temperature and melting temperatures of the pure components are as follows:

• Bi2O3 – 8.90 g/cm3; 817 °C

• WO3 – 7.16 g/cm3; 1473 °C

• CaO – 6.66 g/cm3; 2570 °C

• ZrO2 – 5.89 g/cm3; 2750 °C



Figure 52: Phase diagram of ZrO2 – WO3 system16

16 L. L. Y. Chang, M. G. Scroger, and B. Phillips, J. Am. Ceram. Soc., 50 [4] 211-215 (1967).

Z25



Figure 53: Phase diagram of Bi2O3 – WO3 system17

17 E. I. Speranskaya, Izv. Akad. Nauk SSSR, Neorg. Mater., 6 [1] 149-151 (1970); Inorg. Mater. (Engl. Transl.), 6 [1]

127-129 (1970).

B50

B29

B27

B22 1400 K

1500 K



Figure 54: Phase diagram of CaO – WO3 system18

A.5.3.4. Experiment The gas-film levitation of the above materials appeared to be extremely difficult even compared to previous tests at much higher temperatures. The studied melts demonstrated the combination of all factors that significantly complicates their levitation:

1. High reactivity towards graphite 2. High volatility of the major components (Bi2O3 and WO3) 3. Formation of irregular surface during melting at macro scale 4. High porosity of the pre-melted samples 5. High densities (~7 g/cm3) 6. Low surface tension (<200 mJ/m2)

18 L. L. Y. Chang, M. G. Scroger, and B. Phillips, J. Am. Ceram. Soc., 49 [7] 385-390 (1966).

C25



7. Low viscosity 8. Relatively elevated temperatures (up to 1350 °C)

The following irreversible gas transport (and on contact) reactions are established between the volatile components of melted samples and graphite diffuser:

2 3( ) ( ) ( ) ( )

3( ) ( ) ( )

8( ) 2( ) 3( )

2( ) ( ) ( )

3 3

4 3

2

g graphite Me g

g graphite g

l g g

g graphite g

Bi O C Bi CO

WO C WC CO

ZrWO ZrO WO

ZrO C ZrC CO

+ → +

+ → +

→ +

+ → +

They are limited by the evaporation rate of the initial oxides and can be somewhat more complex involving intermediate reactions which are irrelevant here. One should also keep in mind possible transport of CO from the diffuser to the melted samples, resulting in the formation of, for example, gaseous ZrO(g) or metallic Bi. The major problem is that with the temperature rise the formation of volatile oxides increases (especially for Bi2O3 and WO3) intensifying the formation of a solid crust on the surface of the diffuser. It is not obvious whether the formation of a coating on the surface of a diffuser can affect sample levitation, unless this coating has a bad adhesion towards graphite, which is the case of tungsten carbide. Formation of a loose coating on the surface of the diffuser in conjunction with the extremely small distances between the sample in levitation and the diffuser surface (<100 ms) results in their early contact: high chemical activity of the given melts towards graphite provokes wetting, immediate spreading and failure of the levitation. Moreover, low surface tension and viscosity make the melts prone to high-mode oscillations raising the probability of accidental contact. We shall not go further in the analysis of the levitation difficulties listed above but shall conclude that impossibility to establish long and stable enough levitation of the samples resulted in the following:

1. No measurements of viscosity were attempted. 2. Increase of the uncertainty of the density and surface tension measurements 3. Decrease of the studied temperature interval.

Nevertheless, satisfactory experimental data were obtained for the 6 compositions of interest.

A.5.3.4.1. Experimental setup The scheme of the installation is shown in Figure 55. A drop (1) is levitated above a porous graphite diffuser (2). The system is heated by an inductor (3) connected to a 30 kHz power generator. The electromagnetic field interacts mainly with graphite susceptor (4) and the diffusers (2). In order to decrease the thermal losses and thermal gradient, thermal shield (5) made of fiber graphite is placed around the susceptor. The temperature is measured by means of two bi-chromatic pyrometers (λ1=0.92 and λ2=1.04 µm) and type C thermocouple (6). One pyrometer (8) is focused on the upper surface of the lower diffuser (working interval 1250-3300 °C) and the other pyrometer (9) is focused directly on the sample (working interval 1000-3000 °C). The thermocouple can be positioned inside the upper diffuser or inside the hot chamber in the vicinity of a drop. The latter position is preferable and was used in this work, since temperature readings are not affected by the gas flow rate inside the diffuser. The acquisition system consists of two computers (10) and (13): one for real time video recording from camera (11) at 25 fps and another one for control command and data acquisition at 10 Hz. The video recording is performed through a system of optical filters (12) applying intensive backlighting with a 300 W halogen lamp.



The experiment is performed in inert atmosphere with an absolute pressure of 1.2-1.3 bars. Samples are accurately weighed before and if possible after the test to ensure, that no important change of the mass takes place during the heating. A photo of the VITI hot chamber is provided in Figure 56 to clarify the positioning of the thermocouple.

Figure 55: The scheme of the VITI facility 1 – drop; 2 – lower diffuse; 3 – inductor coil; 4 – susceptor; 5 – thermal shield; 6 – W-Re thermocouple; 7 – holder; 8, 9 – two-color pyrometers; 10 – video acquisition computer; 11 – high-speed camera; 12 – system of low frequency filters; 13 – data acquisition computer; 14 – manometer; 15 – flow meter; 16 – rapid hydraulic elevator and system of accurate vertical adjustment.

Figure 56: VITI hot chamber: outside and inside views



A.5.3.4.2 Experimental procedure

After some preliminary tests, the experiments were conducted between 27.9.2010 and 29.10.2010. Louis Manickam and Pavel Kudinov from KTH went to Cadarache during this period to join the PLINIUS/VITI experimental team supervised by Dmitry Grishchenko. The samples were prepared from fine powders of pure components: manually mixed in glass mortar and pressed in tablets with outer diameter of 6 mm. The initial mass of the samples varied between 0.2 and 0.8 g. The upper limit was chosen based on the computation of drop mass stable in levitation. The smaller masses were taken to improve the liquid sample stability towards the gas flow, in other words to avoid the early surface oscillations due to Kelvin-Helmholtz instability. Three experimental procedures has been attempted in order to succeed the gas-film levitation. They differ in the preparation of the initial samples and applied temperature treatment during the test:

1. Levitation of the fully pre-melted material coming from the DEFOR facility 2. Levitation of the partially melted material 3. Levitation of sintered material with fast temperature rise.

Their development was required since application of the conventional technique (levitation of sintered samples with slow temperature rise) continuously failed the tests during the solid-liquid transition. The problem resulted from the formation of irregular surface of macro scale on samples during melting provoking a contact between the sample and the diffuser. An example of the formation of such structure is provided in Figure 57 (see the caption for comments).

Figure 57: Melting pattern of B50 sample in levitation (from left to right: the image of a sintered sample shortly before melting; the process of sample melting initiated from the top, as soon as melting front will reach the bottom surface of the sample the levitation will fail; sample solidified after surface pre-melting, see the porous character)

Application of pre-melted materials coming from DEFOR facility was unsuccessful: due to the presence of closed porosity (encapsulated gases) which leads to cracks in the samples during heating. Levitation of the partially pre-melted samples provided better results. A pressed sample was placed in the levitation and pre-melted at the top applying predefined temperature gradients. The temperature gradient was controlled by positioning of the upper diffuser and adjustment of the gas-flow rate through it. After the pre-melting, the sample was extracted and polished as it is demonstrated in Figure 58. Further levitation of the sample was performed on the melted and polished surface. Nevertheless long enough levitation still could not be established to perform the measurements within the sufficient temperature interval.



The last method proved to be the best. The basic idea was to pass the solid-liquid transition instantaneously skipping the phase of surface degradation and reaching higher temperatures by fast temperature rise. The pressed sample was sintered in levitation, weighed and then again placed in levitation. During the second levitation cycle the temperature was risen slowly until the melting point and then fast (about 20 °C/sec) supplying up to 40-70 % of the inductor power. The general experimental procedure is as follows. The facility is washed with alcohol and vacuum cleaned from aerosols. The graphite diffuser is polished applying the diamond paste down to 3-6 mc, washed in ultrasonic bath in alcohol during 20-25 min and dried on air at 300 °C. Next, the video camera is focused and scaled applying a series of bearing balls of known diameters. The sintered or partially pre-melted (in levitation) sample is weighed on the precision balance (accuracy down to 10 mg) and placed in levitation. After the assembly of the hot chamber, a K-type thermocouple is passed through the camera’s view port in the hot chamber and positioned 4-5 mm away from the sample and 1-2 mm above the lower diffuser (see Fig. 56). The VITI chamber is sealed and vacuumed during several minutes with continuous supply of argon at about 0.01 bar. Next, the fore-pump is stopped and 1.2-1.3 Bar pressure is established within VITI. At this point the temperature rises, data acquisition and video recording are started. In case of Bi2O3-WO3 system the sample is melted and continuously heated up until the failure of the levitation. Next, the lower diffuser is cleaned: it is overheated up to ~2000 °C in order at first to evaporate the excess of oxides, and then obtain and evaporate (1800 °C) metallic Bi. The remaining deposit of WC is therafter removed by polishing. This procedure allowed repeated usage of the graphite diffusers. In case of ZrO2–WO3 and CaO-WO3 systems the temperature in the hot chamber was measured both by pyrometer and by thermocouple. In order to avoid the melting of the thermocouple during the fast temperature rise, the thermocouple was withdrawn from the VITI hot chamber at around 1100-1200 °C. We should stress that the focusing spot of the pyrometer (∅6 mm) exceeds the sample size and commonly captures the temperature of the susceptor as well. The measuring spot in all tests was positioned in such way that the readings of the pyrometer precisely coincide with the readings of the thermocouple. This was verified before the removal of the thermocouple within 1000 - 1200 °C interval. After the removal of the thermocouple the sample was melted and heated until the failure of levitation. Since ZrO2 and CaO are not volatile and do not form volatile or dissolvable components by interaction with graphite their removal from the surface of diffusers was not possible. The obtained video recordings are afterwards processed in MatLab applying specifically developed for this experiments software IMAGINE. An example of a drop contour fitted with the Laplace equation is provided in Figure 59.

Figure 58: Procedure of sample preparation

From left to right: pressed sample, sample pre-melted in levitation, sample after polishing



Figure 59: Drop of simulant material in levitation and its fitting with the Laplace equation

We should point that several tests have been performed to check the wettability of WO3 based melts on different substrates trying to find the material which is not wetted by WO3. We have studied several metallic surfaces (stainless steel, Ta, Zr) and alumina. The test has been performed both on air (alumina) and in the inert atmosphere (metals, alumina) and in all test the studied melt wetted completely the substrate.

A.5.3.5. Results Measurements of density and surface tension have been performed only during heating, no data during cooling and data for the undercooled state could be acquired. In the presented further results we have given the priority to those tests where continuous readings were obtained in wide temperature interval; if no continuous data were established for a given composition we combined the results of two or more tests where the measurements have been performed successfully but in a very limited temperature interval. The data on density and surface tension is always provided from the same test or series of tests, no “compilation” is made by taking the density measurements from one test and surface tension from another one. If several tests provided essentially the same readings only one would be given here for the sake of clarity. The tables of the experimental points can be provided on demand. Most of the data provided in the following paragraphs have been obtained by fast temperature rise method and very few by levitation of the partially pre-melted samples. The general uncertainty of the density and surface tension measurements is provided in the conclusions; below we point only the scatter of the experimental points for considered tests.

A.5.3.5.1 Density The results of the density measurements are provided in Figure 60. The general trend of density decrease with the change of the qualitative composition agrees with the expected one if we consider the density of the corresponding solid components.



The levitation of the B50 and B29 samples appeared to be the most difficult and provided the most scattered data. The density of B50 composition is obtained in a single experiment; within the studied temperature interval 1140 – 1265 °C it varies around 7.34 g/cm3 never exceeding ±1.5%. Since no clear temperature dependence can be established here we recommend the above value of density for this composition. The data for the B29 sample is a combination of three tests performed with fast temperature rise. The test series can be distinguished from each others as three separate groups of points. Here again we could not establish clear temperature dependence and the average density value of 7.14 g/cm3 with ±2% of uncertainty for given temperature interval (924 – 1138 °С) was estimated. The data for the B27 (eutectic) is obtained in a single experiment and agrees well with the measurements of other tests (not demonstrated here). It provides clear temperature dependence from 990 to 1110 °C which can be assuredly extrapolated. The following linear equation of density (g/cm3) in terms of temperature (°C) is recommended: ρ = -0.001172×t + 7.896. It is surprising that density of B29 significantly exceeds the density of B27, commonly 2% variation of the melt composition cannot effect so strongly on the density of a melt. We suspect that this effect can be caused by formation of the Bi2W2O9 compound which might have a strong positive deviation from the additive law. The data for the B22 melt is obtained in a single run applying relatively slow temperature rise. The obtained data again demonstrates clear temperature dependence and the following equation of density is recommended: ρ = -0.002871× t + 9.271. The levitation of Z26 melts appeared to be difficult due to higher temperatures. The presented data combine the results of two tests. The scatter of the measurements does not allow us to establish temperature dependence of density, but a value of 5.58 g/cm3 can be recommended between 1270 and 1380 °C with ±1.7% of uncertainty.

Figure 60: Results of the density measurements (x= temperature in °C, y= density in g/cm3 in the correlations)



The lowest densities have been measured from C25 samples. Based on two successful tests the following equation is recommended for the density temperature dependence between 1160 and 1300 °C: ρ = -0.0009914× t + 6.603.

A.5.3.5.2. Surface tension The results of the surface tension measurements are provided in Figure 61. The data aretracted from the tests used for the computation of the density. It should be noted that continuous measurement of surface tension often results in the rise of the surface tension for oxide materials; this effect is attributed to the change of the surface chemical composition. The measurements of surface tension performed on Bi2O3-WO3 system provided values mainly between 180 and 200 mJ/m2. The highest surface tension (taking into account higher temperature of measurements) was obtained for B50 sample, the average value 189 mJ/m2 has been estimated between 1150-1260 °C. Regarding B22-B29 three linear dependences of surface tension have been obtained: two of which are similar (B22 and B29) with negative slope and one (B27) has the same order of magnitude but positive slope. The latter has been obtained using continuous measurements from a single test. Such effect is common for oxides and with further temperature rise it will eventually start to decrease. For this reason we propose for these compositions to use a unique equation deduced from the B22 and B29 experimental data: σ = -0.091931×t + 288 where σ is the surface tension, mJ/m2; t is temperature, °C. For the C25 sample the following equation for surface tension can be recommended: σ = -0.1262×t + 316

Figure 61: Results of the surface tension measurements

The measurement of the Z26 melts again provide scattered data, but on the basis of two tests we recommend the following equation for the surface tension: σ = -0.2226×t + 434 For the B22, B27 and B29 compositions which are quite close, the main source of surface tension variation is temperature and there are no clear differences due to composition. Therefore a single correlation has been proposed for these three compositions.



A.5.3.5.3 Viscosity It has not been possible to perform the measurements of viscosity in the periodic relaxation mode during this project thus the efforts have been put on density and surface tension. However, gross estimate of viscosity can be provided based on the observations of melts behaviour by the experimentalist. The kinetics of droplet collapse in case of a contact with the lower diffuser that we could observe for all compositions clearly demonstrates that viscosity of studied melts are far way lower those that can be measured in VITI facility in periodic relaxation mode. This limit is

commonly defined through the Ohnesorge number 2

R

ησ ρ

Ω =⋅ ⋅

, where σ is the surface

tension, ρ is the density, η is viscosity and radius of a spherical drop. Ohnsorge number

Ω = 0.767 specifies the lower limit of the viscosity that can be measured by gas-film levitation applying the periodic relaxation mode. Assuming σ = 200 mJ/m², ρ = 7.0 g/cm3, R = 4mm, the resulting viscosity is η ~ 10 Pa.s. Thus within experimental temperatures the viscosities of considered melts are somewhat below the above value but seemingly above

31 10 Pa s−⋅ ⋅ (the one corresponding to water at room temperature).

A.5.3.6 Conclusions on the VITI experiment Gas-film levitation and contactless measurements of thermophysical properties have been performed on six binary oxide mixtures containing as the major component WO3 and the secondary component one of the following: Bi2O3, ZrO2 and CaO. Because of the significant experimental difficulties in levitation of these materials only density and surface tension could be measured within a limited temperature interval. The results of the tests are summarized in the table below. Composition Density, g/cm3 Surface tension,

mJ/m2 Temperature, °C

B50 7.34 189 1140÷1260 B29 7.14 920÷1140 B27 -0.001172t+7.896 990÷1110 B22 -0.0028707t+9.271

-0.091931t+288

1014÷1130 Z26 5.58 -0.22259t+434 1280÷1380 C25 -0.0009914t+6.603 -0.1262t+316 1160÷1300 VISCOSITY 10000-1 mPa.s Since no stable and long levitation could be established the classical uncertainty of ±3.0% and ±3.5 % for density and surface tension measurements respectively is no more valid. The scatter of the experimental data never exceeded ±3 % on density and ±5 % on surface tension, adding these values to the theoretical ones we can provide an estimate of the error: ±6% for density and ±9% for surface tension.



It is now possible to select the simulant system having the closest properties to those of prototypic corium: It would be Bi2O3-WO3. However, in view of the high volatility of Bi2O3 an alternative choice would be ZrO2-WO3. The difficulty here can be the choice of crucible material for the melting due to elevated temperatures (up to 1500 °C). Since alumina crucibles cannot be used (its eutectic temperature in conjunction with WO3 is below that of ZrO2-WO3), zirconia based crucibles should be recommended. A.6. Scientific output of the users at the facility The CA-U4 experiment plans have been presented with a poster at the European Aerosol Conference19. A journal paper is planned in the near future.

Communications on the VB-U7 experiment have been given at the 2010 ERMSAR Conference20 and at the OECD MCCI Seminar21.

A communication on the VITI experiments is planned at the Materials and Fluids at High Temperature workshop to be held at Orléans in March 2011.

A synthesis paper on the transnational access to the PLINIUS and LACOMECO platforms22 has also been given at the ERMSAR 2010 Conference.

19 Parozzi, F., Caracciolo, E., Herranz, L.E., Housiadas, C., Mitrakos, D., Journeau C. and Piluso, P. (2008). Investigation on aerosol leaks through containment cracks in nuclear severe accidents using prototypic materials. 2008 European Aerosol Science Conference (EAC2008), Thessaloniki, Aug 24-29. 20 C. Journeau, L. Ferry, P. Piluso, J. Monerris, M. Breton, G. Fritz, T. Sevon, Two EU-funded tests in VULCANO to assess the effects of concrete nature on its ablation by molten corium, 4th European Review Meeting on Severe Accident Research (ERMSAR-2010), Bologna-Italy, 11-12 May 2010. 21 Tuomo Sevón, Lionel Ferry, Christophe Journeau, MCCI with Hematite-containing Concrete: HECLA and VULCANO Experiments, OECD MCCI Seminar, Cadarache, 15-17 November 2010. 22 A. Miassoedov, T. Jordan, L. Meyer, M. Steinbrück, W. Tromm, C. Journeau, J.M. Ruggieri, P. Piluso, L. Ferry, P. Fouquart, N. Cassiaut-Louis, LACOMECO and PLINIUS Experimental Platforms at KIT and CEA, 4th European Review Meeting on Severe Accident Research (ERMSAR-2010), Bologna-Italy, 11-12 May 2010.



A.7. User meetings A dedicated meeting of the first user group has been held in Cadarache in January 15, 2009 to discuss the first test results.

Two user group meetings were held in Espoo (Finland) and Cadarache (France) to prepare the 2nd access.

A meeting of the 3rd user group has been held in Cadarache to prepare the VITI experiments.

Date User group Venue Overall Nbr of attendees

Nbr of users attending

15/1/2009 1 (COLIMA) Cadarache 6 3

26/3/2009 2 (VULCANO) Espoo 3 1

30/6/2009 2 (VULCANO) Cadarache 4 1

12-13/6/2010 3 (VITI) Cadarache 5 2 Table VI: Attendance on User meetings Final Meeting On October 26, 2010, a workshop has been jointly organised by CEA and KIT to present the works performed thanks to these European Transnational Access to Large Infrastructure grants. This instrument supports the performance of experiments at European infrastructure for researchers working in countries which do not have equivalent facilities. It is a great tool of integration:

Further to the economical aspect of eliminating redundancy, it is also a very efficient way to built research networks between teams working in the same field in different Member States. It also enabled training of colleagues who were not familiar with the experimental aspects of severe accident research and, as a most valuable counterpart, broadened the host teams’ horizon to new research approaches. Last but not least, the results of these experiments will contribute to the safety analysis of European reactors.

27 participants from 7 European countries (France, Germany, Italy, Slovenia, Spain,

Sweden, Switzerland) participated to the meeting (see list in Annex 5). After an overview of the two projects and of EURATOM activities in support of European Research Infrastructures, the various experimental projects have been presented.

Severe accident experimentation is an applied research that aims at answering the issues raised by reactor safety and are in compliance with the SNE-TP objectives. Among many, we can list:

The COMET facility in Karlsruhe validated the alternate COMET core-catcher concept and the VULCANO facility contributed, thanks to a EURATOM-funded transnational access, to qualify this concept with prototypic UO2-containing melts.

The effects of a pressurized melt ejection in the EPR reactor cavity has been studied with DISCO at KIT.

The ablation of the EPR reactor cavity sacrificial concrete by the molten core has been studied within another transnational access to VULCANO.

Current reactor core bundle degradation has been studied in the QUENCH facility, leading to recommendations for the core reflooding during severe accident sequences.



The retention of fission product aerosols in concrete cracks has been studied with the COLIMA facility.

The LACOMECO experiments, which have been selected in a 2010 Selection Panel session have also been presented and are expected to provide very fruitful results. A final presentation has been devoted to the ALISA proposal in preparation to link the PLINIUS and LACOMECO platforms in a collaboration between EURATOM and China.

Figure 62: Photographs of the PLINIUS-LACOMECO workshop

Acknowledgements The work and efforts of the whole COLIMA, VITI and VULCANO teams at the PLINIUS platform staff (Yves Bullado, Michel Breton, Nathalie Cassiaut-Louis, Patricia Correggio, Lionel Ferry, Gérald Fritz, Dmitry Grishchenko, José Monerris, Pascal Piluso) is gratefully acknowledged as well as of the DTN/STPA/LIPC material analysis laboratory.

Contribution from the scientific users - Flavio Parozzi, Franco Polidoro, Sonia Morandi (RSE), Tuomo Sevon (VTT), Louis Manickam, Pavel Kudinov (KTH) – have been included in this final report. Their continuous support was a key point for the success of these tests, as well as the support from the European Commission and in particular of Michel Hugon.



Annexes Annex 1 - Composition of the Users Selection Panel (section 1.4) The Selection Panel membership is the following • Mrs. Michèle AUGLAIRE, Suez Tractebel, Belgium (for 2nd Call) • Mr. Michel GIOT, Université Catholique de Louvain, Belgium • Mr. Michel HUGON, European Commission, Brussels. • Mrs. Ilona LINDHOLM, VTT, Finland (for 1st and 3rd Calls) • Mr. Christophe JOURNEAU, Commissariat à l’Energie Atomique et aux Energies

Alternatives , France • Mr. Daniel MAGALLON, Joint Research Centre, Netherlands Mr. Gérard COGNET (CEA councillor in Budapest) also contributed to the Selection Panel as an observer.

FP6 EURATOM 56 Contract Number FP6-036403] Transnational Access Final Report

Annex 2 - List of User-Projects Project number

Title Status23 Country Number of CAU

Facility Year of Activity

1 Experimental investigation of leaks through containment cracks in severe accidents using prototypic cracks and prototypic aerosols

C Greece + Italy + Spain

2 COLIMA 2-3

2 Quantification of the H2 releases in severe accidents of VVER 1000 and probability for excess of the ignition and explosive concentrations with a view of the management of the accidents and prevention of the environmental impact.

R Bulgaria 2 KROTOS 2

3 Interaction between Corium and FeSi Concrete (FESICO)

C Finland 6 VULCANO 3

4 Measurements of Simulant Melt Bi2O3-WO3 Physical Properties

C Sweden 1 VITI 4

23 C=completed, O= ongoing (i.e. started, but not yet completed), A=approved, R=rejected and NE= not yet evaluated.


Annex 3 - List of Users User ID

Users Year of visit

Number of visits

Project number

First access to PLINIUS

(Y/N)

Time spent by user at PLINIUS

User category24

User institution Institution type25

T/R reimbursed

1 Christos Housiadas26

Planned in 2008

0 1 Y - EXP “Demokritos” National Centre for Scientific Research

PUB

2 Dimitris Mitrakos26

Planned in 2008

0 1 Y - PGR “Demokritos” National Centre for Scientific Research

PUB

3 Flavio Parozzi 2008 1 1 Y 2 days EXP CESI Ricerca (now RSE)

PUB Yes

4 Franco Polidoro

2008 1 1 Y 2 days EXP CESI Ricerca (now RSE)

PUB Yes

5 Luis E. Herranz

2008 1 1 Y - EXP CIEMAT PUB Yes

6 Tuomo Sevon 2009 2 3 Y 2 + 14 days EXP VTT PUB Yes

7 Pavel Kudinov 2010 2 4 Y 3 + 2 days EXP Royal Institute of Technology

UNI Yes

8 Louis Tamilarasan

2010 2 4 Y 3+3 days PDOC Royal Institute of Technology

UNI Yes

24 UND= Undergraduate, PGR=Post-Graduate (student with a first University degree or equivalent), PDOC= Post-doctoral researcher, TEC= Technician, EXP=Experienced researcher (professional researcher). 25 UNI=University, PUB= Public Research Organisation, PRI=Private Research Organisation, Non Profit, IND= Industrial or Commercial enterprise. 26 Although the project has been launched under the leadership of Demokritos, they did not finally visited PLINIUS and the leadership has been shifted to CESI Ricerca (now RSE).


Annex 4 - List of Publications Parozzi, F., Caracciolo, E., Herranz, L.E., Housiadas, C., Mitrakos, D., Journeau C.

and Piluso, P. (2008). Investigation on aerosol leaks through containment cracks in nuclear severe accidents using prototypic materials. 2008 European Aerosol Science Conference (EAC2008), Thessaloniki, Aug 24-29.

C. Journeau, L. Ferry, P. Piluso, J. Monerris, M. Breton, G. Fritz, T. Sevon, Two EU-funded tests in VULCANO to assess the effects of concrete nature on its ablation by molten corium, 4th European Review Meeting on Severe Accident Research (ERMSAR-2010), Bologna-Italy, 11-12 May 2010.

L.E. Herranz, J. Ball, A. Auvinen, D. Bottomley, A. Dehbi, C. Housiadas, P. Piluso, V. Layly, F. Parozzi, M. Reeks, Progress in understanding key aerosol issues,Progr. Nucl. Energ.,52(1): 120-127 (2010).

Tuomo Sevón, Lionel Ferry, Christophe Journeau, MCCI with Hematite-containing Concrete: HECLA and VULCANO Experiments, OECD MCCI Seminar, Cadarache, 15-17 November 2010.

A. Miassoedov, T. Jordan, L. Meyer, M. Steinbrück, W. Tromm, C. Journeau, J.M. Ruggieri, P. Piluso, L. Ferry, P. Fouquart, N. Cassiaut-Louis, LACOMECO and PLINIUS Experimental Platforms at KIT and CEA, 4th European Review Meeting on Severe Accident Research (ERMSAR-2010), Bologna-Italy, 11-12 May 2010.


FP6 Research Infrastructures 59 Contract Number [RITA-CT-200X-XXXXX] Transnational Access Final Report

Annex 5 - List of Workshop Participants

First name Name Institution

Jean-Michel Bonnet IRSN

Daniel Caruge CEA

Leticia Fernandez-Moguel PSI

Florian Fichot IRSN

Michel Giot SCK-CEN

Dmitry Grishchenko CEA

Luis Enrique

Herranz CIEMAT

Michel Hugon EC

Christophe Journeau CEA

Ivo Kljenak IJS

Pavel Kudinov KTH

Bernard Maliverny EDF

Renaud Meignen IRSN

Alexei Miassoedov KIT

Sonia Morandi RSE

Imre Nagy AEKI

Fréderic Nguyen CEA

Clemente Parga CEA

Flavio Parozzi RSE

Pascal Piluso CEA

Franco Polidoro RSE

Georges Repetto IRSN

Jean-Michel Ruggieri CEA

Tuomo Sevon VTT

Didier Tarabelli CEA

Peter Volkholz AREVA NP GmbH

Magali Zabiego CEA

Documents

Final Progress Report PLINIUS FP6 - CORDIS · Final Progress Report PLINIUS FP6 ... Project coordinator: Christophe JOURNEAU Project website: Project period: from 1/11/2006 to 31