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Victoria multicompartment experiments on hygroscopic and inert aerosol behaviour in LWR containment conditions
J Aerosol Sci. Vol. 30, Suppl. 1, pp. SI03-S104, 1999 O 1999 Published by Elsevier Science Ltd. All rights reserved Printed in Great Britain 0021-8502/99/$ - see front matter
Pergamon
VICTORIA MULTICOMPARTMENT EXPERIMENTS ON HYGROSCOPIC AND INERT AEROSOL BEHAVIOUR IN LWR CONTAINMENT CONDITIONS
J. M. MAKYNEN 1 , -
J. K. JOKINIEMI 1 and E. I. KAUPPINEN 2
VTT Aerosol Technology Group, 1VTT Energy, 2VTT Chemical Technology, P.O.Box 1401, FIN-02044 VTT, FINLAND. and T. ROUTAMO and H. TUOMISTO Fortum Engineering Ltd, Rajatorpantie 8, Vantaa FIN - 01019 IVO, FINLAND
KEYWORDS LWR Reactor Accidents, Hygroscopic Particles, Aerosol Modelling
INTRODUCTION The aim of aerosol experiments in the VICTORIA facility is to validate the containment aerosol models used in the nuclear reactor accident codes. As a final goal we need to confirm that containment aerosol codes are able to calculate correctly the radioactive hygroscopic and nonhygroscopic aerosol behaviour in non-homogeneous multicompartment containments. It is possible to reach this goal by making experiments in a well-instrumented model containment. The VICTORIA multi-compartment test facility (Loviisa nuclear power station model containment with linear scaling 1:15, which gives a volume scaling 1:3375, height 4.6 m and diameter 3.14 m) is well suited for this purpose. In the quantitative containment aerosol behaviour tests with VICTORIA, state-of-the-art aerosol measurement systems are used. Aerosol number and mass concentration is measured continuously using the Condensation Nucleus Counter (CNC) and the Tapered Element Oscillating Microbalance (TEOM) mass monitor. Particle mass and chemical composition size distributions are determined by Berner Low-Pressure Impactors (BLPI). Measurements have also been made with the Electrical Low Pressure lmpactor (ELPI), deposition trays and deposition coupons. VTT has designed an aerosol generation system, which produces soluble aerosol by utilising two opposite jet atomisers. The high temperature Laminar Entrainment Flow Reactor (LEFR) is also used in aerosol generation. This LEFR has 5 individually controllable heating zones and the maximum feasible temperature is 1800°C. By choosing the optimal precursor materials and LEFR operation at high temperature this method can be applied also to generate non-soluble aerosol materials.
SI03
S104
Abstracts of the 1999 EuropeanAerosolConference RESULTS
This paper presents the results of the hygroscopic (CsOH) and inert (Ag) aerosol tests, test numbers 61 and 62, respectively. As the tests were carried out similarly, it is possible to compare the behaviour of inert and hygroscopic aerosol. The experiments started with the steam injection rate of 5 g/s into the preheated lower compartment (steam generator room). Simultaneously the lower inlet doors of the hot side (90 °) ice condenser were opened. The upper deck and the intermediate deck doors were fully open in both ice condensers, but no ice was present during the tests. In order to create the global convective loop through the ice condensers, the cold side (270 °) lower inlet doors were forced open at 1 minute from the start of the test. The steam injection rate was decreased to 2 g/s at 55 minutes, i.e. 5 minutes before the aerosol injection. This procedure was chosen in order to maintain the reached TH conditions and let the loop flow stabilise at the new level before the aerosol injection phase. The aerosol was injected into the upper compartment above the hot side ice condenser, using an Opposite Jet Aerosol Generator between 60 and 90 minutes. Tests ended after duration of about 6 hours.
+4¸30
+6450
+ 2.84
* 42.55
+1.89
÷ 25 4 0
+ 1.20
+ 10.20
+ 10 3
* 15.40
+ 0.70
+ 10.45
+0.00
+ 0.00
1-3 • T E O M and CNC; I-III : ELPI Fig. 1. Schematic diagram of the VICTORIA test system The CsOH feed rate in experiment 61 was about twice the rate in the Ag test (exp. 62) and the dry particle aerodynamic size was approximately the same during both tests. The RH in the loop was 100% and in the lower part of the upper compartment around 90%. The hygroscopic growth and thus larger sedimentation velocity of the CsOH particles resulted in approximately the same maximum mass concentration in the dome region as with Ag aerosols. The CsOH mass concentration in the dome region decreased about twice as fast as Ag concentration.
Pergamon
VICTORIA MULTICOMPARTMENT EXPERIMENTS ON HYGROSCOPIC AND INERT AEROSOL BEHAVIOUR IN LWR CONTAINMENT CONDITIONS
J. M. MAKYNEN 1 , -
J. K. JOKINIEMI 1 and E. I. KAUPPINEN 2
VTT Aerosol Technology Group, 1VTT Energy, 2VTT Chemical Technology, P.O.Box 1401, FIN-02044 VTT, FINLAND. and T. ROUTAMO and H. TUOMISTO Fortum Engineering Ltd, Rajatorpantie 8, Vantaa FIN - 01019 IVO, FINLAND
KEYWORDS LWR Reactor Accidents, Hygroscopic Particles, Aerosol Modelling
INTRODUCTION The aim of aerosol experiments in the VICTORIA facility is to validate the containment aerosol models used in the nuclear reactor accident codes. As a final goal we need to confirm that containment aerosol codes are able to calculate correctly the radioactive hygroscopic and nonhygroscopic aerosol behaviour in non-homogeneous multicompartment containments. It is possible to reach this goal by making experiments in a well-instrumented model containment. The VICTORIA multi-compartment test facility (Loviisa nuclear power station model containment with linear scaling 1:15, which gives a volume scaling 1:3375, height 4.6 m and diameter 3.14 m) is well suited for this purpose. In the quantitative containment aerosol behaviour tests with VICTORIA, state-of-the-art aerosol measurement systems are used. Aerosol number and mass concentration is measured continuously using the Condensation Nucleus Counter (CNC) and the Tapered Element Oscillating Microbalance (TEOM) mass monitor. Particle mass and chemical composition size distributions are determined by Berner Low-Pressure Impactors (BLPI). Measurements have also been made with the Electrical Low Pressure lmpactor (ELPI), deposition trays and deposition coupons. VTT has designed an aerosol generation system, which produces soluble aerosol by utilising two opposite jet atomisers. The high temperature Laminar Entrainment Flow Reactor (LEFR) is also used in aerosol generation. This LEFR has 5 individually controllable heating zones and the maximum feasible temperature is 1800°C. By choosing the optimal precursor materials and LEFR operation at high temperature this method can be applied also to generate non-soluble aerosol materials.
SI03
S104
Abstracts of the 1999 EuropeanAerosolConference RESULTS
This paper presents the results of the hygroscopic (CsOH) and inert (Ag) aerosol tests, test numbers 61 and 62, respectively. As the tests were carried out similarly, it is possible to compare the behaviour of inert and hygroscopic aerosol. The experiments started with the steam injection rate of 5 g/s into the preheated lower compartment (steam generator room). Simultaneously the lower inlet doors of the hot side (90 °) ice condenser were opened. The upper deck and the intermediate deck doors were fully open in both ice condensers, but no ice was present during the tests. In order to create the global convective loop through the ice condensers, the cold side (270 °) lower inlet doors were forced open at 1 minute from the start of the test. The steam injection rate was decreased to 2 g/s at 55 minutes, i.e. 5 minutes before the aerosol injection. This procedure was chosen in order to maintain the reached TH conditions and let the loop flow stabilise at the new level before the aerosol injection phase. The aerosol was injected into the upper compartment above the hot side ice condenser, using an Opposite Jet Aerosol Generator between 60 and 90 minutes. Tests ended after duration of about 6 hours.
+4¸30
+6450
+ 2.84
* 42.55
+1.89
÷ 25 4 0
+ 1.20
+ 10.20
+ 10 3
* 15.40
+ 0.70
+ 10.45
+0.00
+ 0.00
1-3 • T E O M and CNC; I-III : ELPI Fig. 1. Schematic diagram of the VICTORIA test system The CsOH feed rate in experiment 61 was about twice the rate in the Ag test (exp. 62) and the dry particle aerodynamic size was approximately the same during both tests. The RH in the loop was 100% and in the lower part of the upper compartment around 90%. The hygroscopic growth and thus larger sedimentation velocity of the CsOH particles resulted in approximately the same maximum mass concentration in the dome region as with Ag aerosols. The CsOH mass concentration in the dome region decreased about twice as fast as Ag concentration.