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10.O.05 First results of the K A E V E R project on aerosol behaviour in LWR-containments
J. Aerosol Sci.. Vol, 25, Suppl. I. pp. $95-$96, 1994 Copyright~1994, Elsevier Science Lid
Pergamon
10
O
05
.,~o,~, ,,, ~,-=,,,,-,t~,,, A,, r~g,.,. . . . ~, 0021-8502/94 $7.00 + 0.00
FIRST RESULTS OF THE K A E V E R PROJECT ON AEROSOL BEHAVIOUR IN LWR-CONTAINMENTS H.G. SCHEIBEL, G. POSS, and D. WEBER * Battelle Ingenieurtechnik GmbH, Diisseldorfer Str. 9 D-65760 Eschborn * l i e Leipzig GmbH, Torgauer Str. 114, D-04347 Leipzig
KEYWORDS Core melt aerosol; Aerosol settling; LWR-containment; Source Term
Source term, aerosol behaviour and depletion in reactor containments have been studied in the past by numerous large experimental programs, e.g. NSPP at ORNL (USA), DEMONA and VANAM at Battelle Frankfurt (Germany), LACE at Hanford (USA), MARVIKEN at Studsvik (Sweden) (Kartzleiter 86, Rahn 88). Experiments have been performed in single- and multicompartment geometries under complex thermohydraulic conditions, and under the basic assumption, that core melt aerosols differ little in size, shape or components due to the fast evaporation, condensation and coagulation processes in the reactor pressure vessel. Recent experiments to particle generation by a melting LWR-core show the release of multicomponent aerosols consisting of soluble or insoluble particles, with different size and shape into the containment (Teague et al. 89, Bowsher et al. 86, 88). From basic physics particle size, shape (agglomeration degree) or density will influence the settling velocity and solubility. The wellknown phenomena Kelvin effect, Raoult's law, Young's law will influence the condensation (Seheibel et al. 86). The relevance for core melt aerosols in a LWR containment is not clear and need further investigations. The main objectives of the project KAEVER (Kemschmel~_grosolverhalten) are to describe the behaviour of different core melt aerosols under the changing thermohydraulic conditions as expected in a LWR-containment during an accident and to provide a detailed data base for the validation and model improvements of containment codes (Scheibel et al. 92). The influence of different aerosol parameter, such as solubility, particle composition, particle size or size distribution, concentration, shape, and agglomeration state on the aerosol deposition should be determined for "dry", "wet" and for transient humidities. Interactions due to long term depletion of multicomponent aerosols should be identified. Close cooperation between experiment and model calculation should provide a detailed data base for the verification of the improved German containment code FIPLOC-M 1.5. Calculations are performed with FIPLOC and other containment codes to define "critical" test parameters by pre test calculations, and to interprete the measurement results. It is planned, to cover a wide range of thermohydraulic containment conditions and aerosol parameters both typical for LWR-accidents with the KAEVER experiments (see Table 1). $95
H . G . SCHEIBEL et al.
S96
The experimental facility consists of a two furnace aerosol generation system to evaporate aerosol materials, feeding and probe sampling devices, the KAEVER test vessel (cylindric, V = 10 m3; p < 5 bar; T, p, rh-controlled), and the aerosol instrumentation (APS, OPC, DMA + CNC, Berner LPI 25, filter systems, and deposition cups). Aerosol measurements are performed just behind the aerosol generators during the aerosol injection and from three test vessel positions during the depletion phase. Sampling lines and instruments measuring undiluted aerosol are slightly superheated and heat controlled. Pre-experiments to controlled generation of soluble (NaCI, CsI, and CsOH) and insoluble (Ag, SnO2) aerosols been performed. Aerosol concentrations of 10 - 20 g/m 3 and particle sizes below 0.8/um have been observed (Scheibel et al. 93). First experiments in the KAEVER test facility have started now with soluble CsI aerosols. First results concerning the depletion process of soluble aerosols in dry conditions will be presented at the annual meeting in May/June 1994. REFERENCES Bowsher, B.R., Jenkins, R.A., Nichols, A.L., Rowe, N.A. and Simpson, J.A.H. (1986), AEEW-Report, 1991 Bowsher, B.R. and Nichols, A.L. (1988). In: Proc. Water Cooled Reactor Code Evaluation and Uncertainty Workshop (E. Della Loggia and J. Rozen ed.). CEC/OECD Nuclear Science and Technol., EUR 11351, 170 Kanzleiter, T. (1986): DEMONA-Versuche. Battelle-Institut Frankfurt, BIeV-R-65.523-01 Rahn, F.J. (1988). The LWR-Aerosol Containment Experiments. LACE TR-012 TeaguE, H.J. and Torgerson, D.F. (1989). A Generic Overview of Severe Accident Phenomena. In: Proc. of Intern. Sem. on Fission Product Transp. Proc. in Reactor Accidents, Dubrovnik, May 22-25, 1989 Scheibel, H.G. and Porstend6rfer, J. (1986). J. Colloid Interf. Science 109, 261 and 109, 275 Scheibel, H.G., G. Poss and D. Weber (1992), European Aerosol Conference 1992, Oxford/GB Scheibel, H.G., G. Poss and D. Weber (1993), European Aerosol Conference 1993, Duisburg, Germany ; Test Sedes
Thermohydraullc Conditions Pressure
p
Tempamtum
T = 80"C-120"C
Humidity
rh =
=
Single Component Tests: solubility, compositid(1 parlide size (pdmaff pad., agglomerates) p a a i c l e shape (chains, agglomerates, single spheres) paaicle ¢on~mtration
0.13MPa-0.26MPa
0 . 6 - • 1.0
Multicomponsn! Tests: soluble -- insoluble small particles ~ large particles (agglom.) Aerosol Parameter
Transient Experiments
Particle Materials: soluble: Csl, CsOH (NaCI) insoluble: Ag, S n O 2 (Fe20=)
Change
of rel. h u m i d i t y :
rh = 0.6 ~ Fh 2:1.0 rh - 1.0 - - rh = 0 . 6
Particle Sizes: primary particles: single particles, small: single pal'tides, large: Agglemarmes: long chains: lumped chains: spheres with small particle deposits: Concentration:
d < 0.1 / u r n d = 0 . 3 / J m - 0.8 sum d = 1.0/urn - 5 pm
Variations of feeding: feeding time. feeding order mixture of component in vessel/outside vessel mass relation of different components
d~,.~,. - 5 , u m
de... . = 1 ~m dr..,
- 5
,urn
~= 1 turn
C ~; 10 g / m =
Table 1: KAEVER-Experiments
Pergamon
10
O
05
.,~o,~, ,,, ~,-=,,,,-,t~,,, A,, r~g,.,. . . . ~, 0021-8502/94 $7.00 + 0.00
FIRST RESULTS OF THE K A E V E R PROJECT ON AEROSOL BEHAVIOUR IN LWR-CONTAINMENTS H.G. SCHEIBEL, G. POSS, and D. WEBER * Battelle Ingenieurtechnik GmbH, Diisseldorfer Str. 9 D-65760 Eschborn * l i e Leipzig GmbH, Torgauer Str. 114, D-04347 Leipzig
KEYWORDS Core melt aerosol; Aerosol settling; LWR-containment; Source Term
Source term, aerosol behaviour and depletion in reactor containments have been studied in the past by numerous large experimental programs, e.g. NSPP at ORNL (USA), DEMONA and VANAM at Battelle Frankfurt (Germany), LACE at Hanford (USA), MARVIKEN at Studsvik (Sweden) (Kartzleiter 86, Rahn 88). Experiments have been performed in single- and multicompartment geometries under complex thermohydraulic conditions, and under the basic assumption, that core melt aerosols differ little in size, shape or components due to the fast evaporation, condensation and coagulation processes in the reactor pressure vessel. Recent experiments to particle generation by a melting LWR-core show the release of multicomponent aerosols consisting of soluble or insoluble particles, with different size and shape into the containment (Teague et al. 89, Bowsher et al. 86, 88). From basic physics particle size, shape (agglomeration degree) or density will influence the settling velocity and solubility. The wellknown phenomena Kelvin effect, Raoult's law, Young's law will influence the condensation (Seheibel et al. 86). The relevance for core melt aerosols in a LWR containment is not clear and need further investigations. The main objectives of the project KAEVER (Kemschmel~_grosolverhalten) are to describe the behaviour of different core melt aerosols under the changing thermohydraulic conditions as expected in a LWR-containment during an accident and to provide a detailed data base for the validation and model improvements of containment codes (Scheibel et al. 92). The influence of different aerosol parameter, such as solubility, particle composition, particle size or size distribution, concentration, shape, and agglomeration state on the aerosol deposition should be determined for "dry", "wet" and for transient humidities. Interactions due to long term depletion of multicomponent aerosols should be identified. Close cooperation between experiment and model calculation should provide a detailed data base for the verification of the improved German containment code FIPLOC-M 1.5. Calculations are performed with FIPLOC and other containment codes to define "critical" test parameters by pre test calculations, and to interprete the measurement results. It is planned, to cover a wide range of thermohydraulic containment conditions and aerosol parameters both typical for LWR-accidents with the KAEVER experiments (see Table 1). $95
H . G . SCHEIBEL et al.
S96
The experimental facility consists of a two furnace aerosol generation system to evaporate aerosol materials, feeding and probe sampling devices, the KAEVER test vessel (cylindric, V = 10 m3; p < 5 bar; T, p, rh-controlled), and the aerosol instrumentation (APS, OPC, DMA + CNC, Berner LPI 25, filter systems, and deposition cups). Aerosol measurements are performed just behind the aerosol generators during the aerosol injection and from three test vessel positions during the depletion phase. Sampling lines and instruments measuring undiluted aerosol are slightly superheated and heat controlled. Pre-experiments to controlled generation of soluble (NaCI, CsI, and CsOH) and insoluble (Ag, SnO2) aerosols been performed. Aerosol concentrations of 10 - 20 g/m 3 and particle sizes below 0.8/um have been observed (Scheibel et al. 93). First experiments in the KAEVER test facility have started now with soluble CsI aerosols. First results concerning the depletion process of soluble aerosols in dry conditions will be presented at the annual meeting in May/June 1994. REFERENCES Bowsher, B.R., Jenkins, R.A., Nichols, A.L., Rowe, N.A. and Simpson, J.A.H. (1986), AEEW-Report, 1991 Bowsher, B.R. and Nichols, A.L. (1988). In: Proc. Water Cooled Reactor Code Evaluation and Uncertainty Workshop (E. Della Loggia and J. Rozen ed.). CEC/OECD Nuclear Science and Technol., EUR 11351, 170 Kanzleiter, T. (1986): DEMONA-Versuche. Battelle-Institut Frankfurt, BIeV-R-65.523-01 Rahn, F.J. (1988). The LWR-Aerosol Containment Experiments. LACE TR-012 TeaguE, H.J. and Torgerson, D.F. (1989). A Generic Overview of Severe Accident Phenomena. In: Proc. of Intern. Sem. on Fission Product Transp. Proc. in Reactor Accidents, Dubrovnik, May 22-25, 1989 Scheibel, H.G. and Porstend6rfer, J. (1986). J. Colloid Interf. Science 109, 261 and 109, 275 Scheibel, H.G., G. Poss and D. Weber (1992), European Aerosol Conference 1992, Oxford/GB Scheibel, H.G., G. Poss and D. Weber (1993), European Aerosol Conference 1993, Duisburg, Germany ; Test Sedes
Thermohydraullc Conditions Pressure
p
Tempamtum
T = 80"C-120"C
Humidity
rh =
=
Single Component Tests: solubility, compositid(1 parlide size (pdmaff pad., agglomerates) p a a i c l e shape (chains, agglomerates, single spheres) paaicle ¢on~mtration
0.13MPa-0.26MPa
0 . 6 - • 1.0
Multicomponsn! Tests: soluble -- insoluble small particles ~ large particles (agglom.) Aerosol Parameter
Transient Experiments
Particle Materials: soluble: Csl, CsOH (NaCI) insoluble: Ag, S n O 2 (Fe20=)
Change
of rel. h u m i d i t y :
rh = 0.6 ~ Fh 2:1.0 rh - 1.0 - - rh = 0 . 6
Particle Sizes: primary particles: single particles, small: single pal'tides, large: Agglemarmes: long chains: lumped chains: spheres with small particle deposits: Concentration:
d < 0.1 / u r n d = 0 . 3 / J m - 0.8 sum d = 1.0/urn - 5 pm
Variations of feeding: feeding time. feeding order mixture of component in vessel/outside vessel mass relation of different components
d~,.~,. - 5 , u m
de... . = 1 ~m dr..,
- 5
,urn
~= 1 turn
C ~; 10 g / m =
Table 1: KAEVER-Experiments