JET exhaust detritiation system replacement - Design, commissioning, and operation

Abstract

The exhaust detritiation system (EDS) of the Joint European Torus (JET) active gas handling system removes tritium from exhaust gases and contaminated air prior to discharge to stack. The system was replaced prior to JET's tritium experimental campaign due to corrosion damage. In this paper, the following topics are presented: system function and description, corrosion and failure of the previous EDS, enhancements for the replacement EDS including testing of acid passivation column, commissioning experience, operating experience and performance. Acids including hydrofluoric were generated in catalytic recombiners following inadvertent halogen ingress. Pitting corrosion was identified with breakthrough failure of condensate pipework. To mitigate a recurrence, a novel acid passivation sub-system was designed. The acid passivation testing demonstrated successful performance of the design and calcium-hydroxide passivation packing tested, with acids below the limit of detectability at the test column outlet. Issues encountered during commissioning are described and key performance metrics such as detritiation factor reported. Finally, operational issues and system performance is presented.