Kinetics in severe reactor accidents
The third meeting of the European Severe Accident Chemistry Group (ESACG) was held on the subject of kinetics in severe reactor accidents. There were a number of presentations on fuel release and primary circuit kinetics. Various experimental programmes on fission product release and transport were described, together with modelling studies using the MITRA, FUTURE, FPREKI and FPCHEM codes. The results from the latter clearly show that the instantaneous equilibrium assumption used by thermochemistry-based codes needs to be validated. Experimental programmes on primary circuit reaction kinetics were presented. The results from the AEA, Winfrith Technology Centre programme show that it is unlikely that an accident situation could arise where reaction rates could be limited by passivation of the surface (i.e. parabolic reaction kinetics), and mass transfer effects (i.e. linear reaction kinetics) were more likely to have an effect and prevent the attainment of equilibrium. However, quantification of mass transfer rules was difficult due to inadequacies in gas diffusivity data. The DEVAP programme of experiments was shown to have the potential for producing very important separate-effects data, that may be useful for interpretation of the forthcoming Phebus-FP programme.
Bibliographic Reference: EUR 15056 EN (1993) 20 pp., FS, free of charge
Availability: Available from Joint Research Centre, Publication Department, I-21020 Ispra (Va.) (IT)
Record Number: 199511397 / Last updated on: 1995-10-31
Original language: en
Available languages: en