The Phebus Fission Product and Source Term International Programmes

The international Phebus FP programme, initiated in 1988 is one of the major research programmes on light water reactors severe accidents. After a short description of the facility and of the test matrix, the main outcomes and results of the first four integral tests are provided and analysed. Several results were unexpected and some are of importance for safety analyses, particularly concerning fuel degradation, cladding oxidation, chemical form of some fission products, especially iodine, effect of control rod materials on degradation and chemistry, iodine behaviour in the containment. Prediction capabilities of calculation tools have largely been improved as a result of this research effort. However, significant uncertainties remain for a number of phenomena, requiring detailed physical analysis and implementation of improved models in codes, sustained by a number of separate-effect experiments. This is the subject of the new Source Term programme for a better understanding of the phenomenology on important safety issues, in accordance with priorities defined in the EURSAFE project of the 5 th European framework programme aiming at reducing the uncertainties on Source Term analyses. It covers iodine chemistry, impact of boron carbide control rods degradation and oxidation, air ingress situations and fission product release from fuel. Regarding the interpretation of Phebus, an international co-operation has been established since over ten years, particularly helpful for the improvement and common understanding of severe accident phenomena. Few months ago, the Phebus community was happy to welcome representatives of a large number of organisations from the following new European countries: the Czech republic, Hungary, Lithuania, Slovakia, Slovenia and also from Bulgaria and Romania.

[1]  Luis E. Herranz,et al.  Validation of severe accident codes against Phebus FP for plant applications: Status of the PHEBEN2 project , 2003 .

[2]  Martin Steinbrück,et al.  Core Loss during a Severe Accident (COLOSS). , 2003 .

[3]  G. Ducros,et al.  Fission product release under severe accidental conditions ; General presentation of the program and synthesis of VERCORS 1-6 results , 2001 .

[4]  M Schwarz,et al.  Applicability of Phebus FP results to severe accident safety evaluations and management measures , 2001 .

[5]  Borut Mavko,et al.  SIMULATION OF CONTAINMENT PHENOMENA DURING THE PHEBUS FPT1 TEST WITH THE CONTAIN CODE , 2002 .

[6]  Elisabeth Krausmann,et al.  Reaction Kinetics of a Fission-Product Mixture in a Steam-Hydrogen Carrier Gas in the Phebus Primary Circuit , 2003 .

[7]  Johan Carlsson,et al.  Two-Dimensional Effects in Thermophoretic Particle Deposition: the PHEBUS-FP Steam Generator. , 2001 .

[8]  Marc Barrachin,et al.  Fission product release in the first two PHEBUS tests FPT0 and FPT1 , 2005 .

[9]  M. Kissane,et al.  IODINE CHEMISTRY AND MITIGATION MECHANISMS , 2003 .

[10]  Luis E. Herranz,et al.  Iodine Behaviour under LWR Accident Conditions: Lessons Learnt from Analyses of the First Two Phebus FP Tests , 2006 .

[11]  P. von der Hardt,et al.  PHEBUS FP: a severe accident research programme for current and advanced light water reactors , 1999 .

[12]  L. N. Kmetyk,et al.  A review of the technical issues of air ingression during severe reactor accidents , 1994 .

[13]  S. Güntay,et al.  Phébus-FP: Results and significance for plant safety in Switzerland , 2005 .

[14]  Sandro Paci,et al.  Thematic network for a Phebus FPT1 international standard problem (THENPHEBISP) , 2005 .

[15]  M. P. Kissane,et al.  Interpretation of fission-product transport behaviour in the Phébus FPT0 and FPT1 tests , 2006 .

[16]  R. Dubourg,et al.  A qualitative comparison of barium behaviour in the PHEBUS FPT0 test and analytical tests , 2001 .