1. Eric Mathet, OECD-NEA MASCA Seminar June 2004 PROJECT USE ONLY 1

2. Eric Mathet, OECD-NEA MASCA Seminar June 2004 PROJECT USE ONLY 2 Special thanks to Organizing Committee Members and to the IRSN staff for its help with the organization

3. Eric Mathet, OECD-NEA MASCA Seminar June 2004 PROJECT USE ONLY 3 OECD - RASPLAV –the corium melt behaved comparably to the simulant material in its natural circulation, therefore previous evaluations based on simulant material data could be scaled to prototypic reactor conditions –BUT... OECD - MASCA Sufficient knowledge of fission product spatial and chemical distributions in the melt pool as well as prototypic liquid corium stratification is lacking. Well ‑ designed experiments obtained with corium compositions prototypical of power reactors was supposed to provide the technical support for assessments of the in- vessel melt pool retention strategy as well as of ex-vessel phenomena. To address the conditions under which molten core material can be retained inside the reactor pressure vessel (RPV) by cooling of the vessel from outside 1994 - 1999 2000 - 2003 - 2006 OECD – MASCA2 The influence of an oxidizing atmosphere and the impact of non- uniform temperatures (presence of crusts or solid debris) is addressed in addition to scaling effects. The program is also intended to generate data on relevant physical properties of mixtures and alloys.