Transient nature of riverbank filtered drinking water supply systems - A new challenge of natural radioactivity assessment.

In Hungary the drinking water supply is mainly based on groundwater, in which radionuclides are common components. Since the mobility of the most common radionuclides, uranium and radium, is strongly influenced by the geochemical conditions, knowledge on the geochemical parameters of water is required. This depends on the flow system and the flow regime.

Natural radioactivity of thermal springs and related precipitates in Gellért Hill area, Buda Thermal Karst, Hungary.

The elevated radioactivity of the thermal waters of Buda Thermal Karst (BTK), Hungary is known and studied since the beginning of the 20th century. In the recent studies, the anomalous Rn/Ra ratios have drawn the attention to the existence of local Rn source. Biogeochemical precipitates (i.

Uranium in groundwater - The importance of hydraulic regime and groundwater flow system's understanding.

Uranium and other natural radionuclides are common components in groundwater, but they are not routinely measured. In drinking water their total activity is screened, but in the evaluation of the measured values usually the aquifer material is only considered. However, the occurrence of radionuclides in groundwater is strongly affected by flow systems and their geochemical characteristics.

Radon as a natural tracer for underwater cave exploration.

The Molnár János cave is one of the largest hypogenic caves of the Buda Thermal Karst (Budapest, Hungary) and mainly characterized by water-filled passages. The major outflow point of the waters of the cave system is the Boltív spring, which feeds the artificial Malom Lake. Previous radon measurements in the cave system and in the spring established the highest radon concentration (71 BqL) in the springwater.