Tellurium transport in the RCS under conditions relevant for severe nuclear accidents

0545189 - ÚJF 2022 RIV GB eng J - Journal Article
Espegren, F. - Karkela, T. - Pasi, A.-E. - Tapper, U. - Kučera, Jan - Lerum, H. V. - Omtvedt, J. P. - Ekberg, C.
Tellurium transport in the RCS under conditions relevant for severe nuclear accidents.
Progress in Nuclear Energy. Roč. 139, SEP (2021), č. článku 103815. ISSN 0149-1970. E-ISSN 1878-4224
Research Infrastructure: CANAM II - 90056; Reactors LVR-15 and LR-0 II - 90120
Institutional support: RVO:61389005
Keywords : Tellurium * Caesium iodide * trasport * RCS * interaction * severe nuclear accident
OECD category: Nuclear related engineering
Impact factor: 2.461, year: 2021
Method of publishing: Limited access
https://doi.org/10.1016/j.pnucene.2021.103815

In the case of a severe nuclear power plant accident, tellurium is one of the more problematic and volatile fission products. If released it could become a health issue as it decays to iodine which accumulates in the thyroid gland. Research exists, that indicates tellurium likely interacts with caesium under severe accident conditions, thus it is important to further explore related phenomenon. In this work, tellurium was exposed to high temperature under oxidizing and inert conditions simulating severe accident conditions with and without airborne caesium iodide to determine the effect on the tellurium source term.

The effect of caesium iodide was noticeable on tellurium transport behaviour in the gas phase under oxidizing and inert conditions. Under humid oxidizing conditions with caesium iodide, no significant impact on the total aerosol mass transport was noticed. However, less tellurium was transported through the model primary circuit and a potentially new compound was observed on the filter located after this model. Comparing inert dry to humid with caesium iodide showed an increase in the total aerosol mass transport whereas there was a decrease noticed of the tellurium reaching the filter after the model primary circuit. In the latter case, new unidentified compound(s) correlated to caesium, iodine and tellurium were observed on the filter located after the model.

In this work, evidence was found that tellurium behaviour will be affected by caesium iodide under the investigated conditions. Moreover, it seems that under inert conditions the formed compounds may be stable at close to ambient temperatures. Unlike under oxidizing conditions, where dissociation likely occurred.
Permanent Link: http://hdl.handle.net/11104/0321926