Community Research and Development Information Service - CORDIS

Abstract

In a sever nuclear accident fission products and structure materials are released from the reactor core into the primary coolant circuit of the plant. Soon after their release, the fission products are predicted to form particles in the relatively cooler regions of the circuit. The transport of the fission products through the primary circuit and their subsequent release into the containment building is this largely dependent on the size distribution of those particles. (Wright ed, 1994). The Phebus programme provides a unique opportunity to measure the aerosol size distribution of the released particles as well as the radio nuclides composition.

The condition in the Phebus experiments place special requirements on the measurement set-up. First of all, the environment is highly radioactive. In the previous experiments, a large amount of material has been released from the Phebus FP fuel bundle. In addition to this, substantial and rapid changes in the aerosol concentration have been observed during the experiments. As a further complication the steam rich atmosphere changes temporarily to a hydrogen rich atmosphere due to very extensive zircaloy oxidation. Also, the temperatures of 700 degrees Celsius and 150 degrees Celsius and the pressure of 2.5 bars make the impactor measurements challenging. (Hanniet-Girault and Repetto eds 1998).

In this work the set-up for the Phebus diluted impactor measurements was developed. The system was tested in various conditions and the results were compared to data obtained with the Berner low-pressure impactor (BLPI). I).

Additional information

Authors: AUVINEN A, VTT Energy, Aerosol Technology, Espo (FI);JOKINIEMI J.K, VTT Energy, Aerosol Technology, Espo (FI);MKYNEN J, VTT Energy, Aerosol Technology, Espo (FI);COCHAUD C, IPSN/DRS Cadarache (FR);ZEYEN R, EC JRC/ISIS at Phebus Programme, Cadarache (FR)
Bibliographic Reference: An oral report given at: European Aerosol Conference. Organised by: The European Aerosol Assembly (EAA). Held in: Leipzig (DE) 3-7 September (2001)
Record Number: 200013773 / Last updated on: 2001-09-18
Category: PUBLICATION
Original language: en
Available languages: en