Fuel behaviour under transient and LOCA conditions. Proceedings of a technical committee meeting

At the invitation of the Government of Norway and in response to a proposal of the IAEA Technical Working Group on Water Reactor Fuel Performance and Technology (TWGFPT), the IAEA convened a Technical Committee Meeting on Fuel Behaviour under Transient and LOCA Conditions in Halden, Norway from 10 to 14 September 2001. The meeting was organized in co-ordination with OECD/NEA and was hosted by the Institutt for Energiteknikk OECD Halden Reactor Project (HRP). This meeting is the seventh in a series of IAEA meetings that were held in 1980 (jointly with OECD/NEA, Helsinki, Finland), 1983 (Riso, Denmark), 1986 (Vienna, Austria), 1988 (Preston, United Kingdom), 1992 (Pembroke, Ontario, Canada) and 1995 (Dimitrovgrad, Russian Federation). All of these activities have significantly contributed to the enhanced understanding of fuel behaviour at accident conditions. In the six years since the last meeting took place, the demands on fuel duties have increased including higher burnup, longer fuel cycles and higher temperatures. To satisfy these demands, fuel vendors develop and introduce new cladding and fuel materials and designs to provide sufficient safety margins, especially under accident conditions. This has incurred a need for assessing the applicability of the database for clarification of safety criteria as well as models for accident evolution predictions. Thus, national and international experimental programmes have been launched, and models are being developed or adapted to consider the changed conditions, e.g. fission gas behaviour, relocation of cracked fuel, and physical property changes of the cladding. Forty-three specialists in experiments and modelling of fuel performance at accident conditions from 15 countries and the OECD Nuclear Energy Agency and 10 observers (Norwegian and foreign representatives to the OECD HRP) took part in the meeting in order to gather and discuss existing knowledge on the subject and to identify the needs for further efforts. Twenty papers were presented at four sessions covering review of fuel research relevant to transient and accident conditions, transient analysis, cladding properties after high temperature oxidation and high burnup phenomena relevant to LOCA