Speaker
Description
Authors (affiliation): Simona Zaharov (SNN-Cernavoda NPP, Romania; UPB, Romania),
L. Samson, A. Nedelcu, V. Tudorache (SNN-Cernavoda NPP, Romania)
Tritium can be found in several forms, such as gaseous (HT, HTO), liquid (HTO or organic molecules in solution) or organically bound tritium (OBT), which can become incorporated into living organisms (vegetables, animals, humans). The complexity and the probability of increasing concentrations were the promotors for the research and development of laboratory methods that enable to accurately determine the various species of tritium in the environment for public and regulatory assurance. After the improvements of analytical data, it will be possible to evaluate the behavior of tritium in the environment, focusing on potential accumulation of OBT in organisms.
The measurement of tritium in its various forms is an important key step for health and environmental risk assessment. However, even in cases where tritium monitoring of atmospheric and liquid releases is currently carried out, very few countries are measuring OBT. In Romania, OBT has become of increased interest for the Cernavoda Nuclear Power Plant (NPP), to include its analysis in a monitoring program, which is important to estimate more accurately the doses for the public.
For this purpose, the Environmental Control Laboratory of the Cernavoda NPP collaborates with other laboratories to organize intercomparison exercises at the international level for OBT analysis in different matrices of environmental samples. If the number of participating laboratories is statistically reached, the evaluation of the OBT intercomparison results can provide a few essential indicators: the homogeneity of the matrix; the repeatability and traceability of the methods; the consensus values of the exercise for tritium concentration in the combustion water and for OBT concentration in the dry matter. The stability of the matrix depends on the storage conditions and this parameter can be determined after running the OBT analysis periodically on the matrix of interest, which can be then recommended to be used as a reference material.
