The French Institute for Radiological Protection and Nuclear Safety (IRSN) and the European Commission's Joint Research Center (JCR) will be holding the fifth seminar devoted to Phebus FP, the international nuclear research safety program, in Aix en Provence on June 24-26, 2003.

The seminar, which presents the world's most important safety research program concerning nuclear power plants, will draw more than a hundred nuclear safety experts and scientists from Japan, Canada, the United States, and countries in both Western and Eastern Europe.

Five experiments on severe accidents

The program includes experiments to reproduce all the phenomena involved during a core meltdown accident and contributing to the release of radioactive products. Its aim is to provide further insight into the complex phenomena encountered during this type of accident. This should improve the action taken to limit the impact of the accident by providing more accurate assessments, and optimize the emergency plans set up around plants. The knowledge acquired could also help to make future nuclear power plants even safer.

Partners and resources: the international dimension of Phebus FP

The Phebus FP program is conducted by IRSN in association with the European Commission JRC, EdF, and American, Canadian, Japanese, Korean, and Swiss nuclear safety organizations. Launched in 1993 with an initial test, it has an estimated cost of €300 million.

An unrivaled experimental setup

The experimental setup, installed in the heart of the Phebus reactor operated by the CEA at its Cadarache research center, is a small-scale replica of a pressurized water reactor, the most widely used type of nuclear power reactor in the world. The setup has undergone considerable change since the end of the 1980's to ensure the efficiency and safety of the Phebus FP tests. In particular, its building was reinforced before the program started to withstand the severest earthquakes liable to occur on the site (intensity IX on the MSK scale, which comprises twelve levels of intensity).

Performing an experiment

Each experiment is prepared with meticulous care, making extensive use of predictive calculations obtained using a variety of software programs. In this way, the experimental protocol can be established and the criteria for ending the experiment defined. This preparatory phase lasts about four years.

Specific objectives for each test

So far, four tests have been successfully completed and the next (and last) test is planned for 2004. The first experiments yielded original results on core meltdown mechanisms and iodine volatility. They were used in more recent evaluations of the radioactive releases to be considered in the preparation of emergency plans.
Furthermore, the OECD has chosen the second experiment in the program as a reference for a standard international exercise involving 30 organizations from 20 countries aimed at testing the performance of various severe accident simulation codes.

Audrey Lebeau / Press Office - 33 (0)1 58 35 82 70
mail: audrey.lebeau@irsn.fr

Gilles Bertin-Maghit - 33 (0)4 42 25 32 53
mail: gilles.bertin-maghit@irsn.fr