Organization / Localization: VTT Country: Germany Facility Description: Aerosol and Heat Transfer Measurement Device.
Vessel of 1.81 m3, radius 63.5 cm and height 142.5 cm. Test Identification: AHMED (VTT,Espoo) SA-Related Topics / Phenomena:Effects of high relative humidity of atmosphere in aerosol particle growth by hygroscopicity. The phenomena were addressed by comparing non-hygroscopic (AgNO3) and hygroscopic (NaOH,CsI) CsOH) aer osol particles. Measured Parameters: T (gas, inner and outer wall surface, surroundings), P, RH, aerosol number and mass concentration, dry size of particles, mass concentrations (CsI, CsOH, NaOH, Ag, Cs) Modelling: Free volume of tests vessel 1.81 m3, homogeneous thermal-hydraulic conditions in the vessel. Berner low pressure impactors were used for particle mass and number concentration was measured with TEAM and particle size and chemical composition was determined from the with Berner low pressure impactor samples. Relative humidity ranged 7 % to 97 %. The test vessel pressure was atmospheric and the atmosphere temperature ranged from 19 oC to 51oC. Simulation Code: MELCOR
IDRA
CONTAIN
FIPLOC-MI
MACRES
NAUAHYGROS Experimental Research Program: YKÄ, Research Programme on Nuclear Power Plant Systems Behaviour and Operational Aspects of Safety Link to PIRT: WP-1.5 ST-11
The experimental data was used to validate analytical models used in severe accident codes (CONTAIN, NAUA-HYGROS)
References: [1] Mäkynen J., Jokiniemi J., Ahonen P., Kauppinen E., Zilliacus R., ""AHMED experiments on hygroscopic and inert aerosol behaviour in LWR containment conditions: experiments results""., Nuclear Engineering and Design 178 (1997) 45 - 59.
[2] NEA, «AHMED code comparison exercise», October 1995
Implemented as part of the Seaknot EU funded project (HORIZON-EURATOM-2021-NRT-01 under Grant Agreement No. 101060327) - WP2.6 UNIPI (2024-2026)