The OECD/NEA ThAI Project was conducted between January 2007 and December 2009. The 70 experiments were performed in the ThAI facility in Frankfurt, the name of which is an acronym for "Thermal-hydraulics, Hydrogen, Aerosols, Iodine". Within the OECD/NEA ThAI project, the following test series have been performed:
A concluding seminar on the main outcome of the ThAI Project was organised on 6-7 October 2010.
The objective of this THAI2 follow-up project is to address remaining questions and to provide specific Water Cooled Reactors aerosol and iodine issues and hydrogen mitigation under accidental conditions. The Project addresses open questions concerning the behaviour of: a) ) Release of gaseous iodine from a flashing jet, iodine deposition on aerosol particles, b) Hydrogen combustion during spray operation and Passive Autocatalytic Recombiner operation in case of extremely low oxygen content. The understanding of the respective processes is essential for evaluating the amount of airborne radioactivity during accidents with core damage (iodine and aerosols) and for containment integrity (hydrogen). The Programme will generate valuable data for these. Concerning fission products the programme will focus on iodine release from a flashing jet and gaseous iodine deposition on aerosols. Regarding hydrogen mitigation the programme will focus on its combustion during spray operation and on its effective removal by means of passive autocatalytic recombiners when approaching oxygen starvation. An analytical effort will accompany the experimental programme, mainly consisting of code calculations for pre-test assessments, result evaluations and extrapolation to reactor situations.
By means of experiments in the THAI facility, safety-relevant improvements in the issues referred to in the proposed experimental programme can be achieved:
Canada, Czech Republic, Finland, France, Germany, Hungary, Japan, Republic of Korea, the Netherlands, Sweden and the United Kingdom.
August 2011 to July 2014
Euros 3.6 million
Last reviewed: 23 October 2013