Objectives, test matrix and representativity of the PHEBUS-FP experimental programme
The Phebus FP experimental programme is a logical continuation of the international effort undertaken several years ago to quantify the source term for LWRs, following the occurrence of a severe accident. Despite extensive effort, no in-pile experiment has been performed in which all the main components and, therefore, all the major phenomena involved in the transport of fission products from the core to the containment walls are represented in an integrated system. The general objective of the Phebus FP programme is to offer such a full integration of the most important phenomena. In order to achieve this, the experimental facility is designed to scale down the components of the primary circuit and the containment vessel by a factor of 5000. In each component of the experimental facility the thermohydraulic boundary conditions are controlled, to maintain representative conditions. The test matrix includes six independent tests, the first of which will be performed utilising fresh fuel, while the other five tests will benefit from the use of preirradiated fuel with burn-up ranging from 23 to 33 GWd/ton. The test parameters chosen for the fuel bundle are those which are expected to affect not only the FP release and speciation, but also the mechanical degradation of the fuel. In the primary circuit, the configuration of the components is defined on the basis of a reference severe accident sequence. The components represented are steam generator, pressuriser, relief tank, low pressure injection system piping, etc. In the containment vessel the test parameters are defined with respect to the postulated physical and chemical processes taking place in the atmosphere and in the sump water. Specific phenomena affecting the FP transport, such as the thermal resuspension from pipe walls and the effect of recirculation spray on FP chemistry in the containment, are also taken into consideration.
Bibliographic Reference: Paper presented: PHEBUS-FP Seminar, Cadarache (FR), June 5-7, 1991
Availability: Available from (1) as Paper EN 36265 ORA
Record Number: 199110806 / Last updated on: 1994-12-02
Original language: en
Available languages: en