The large variation in the ratio of uranium-234 to uranium-238 (234U/238U) in rivers is not well understood, but may provide information about past weathering and rainfall and is important because it controls seawater (234U/238U). Here, we demonstrate the importance of physical weathering and rainfall for (234U/238U), using rivers from South Island, New Zealand. These data allow interpretation ...

Constraining the history of seawater (234U/238U) is important because this ratio is used to assess the validity of U/ Th ages, and because it provides information about the past rate of physical weathering on the continents. This study makes use of U-rich slope sediments from the Bahamas in an attempt to reconstruct seawater (234U/238U) for the last 800 kyr. For the last 360 kyr, U/Th dating of...

In the study the activities of polonium 210Po and uranium 234U, 238U radionuclides in moss and lichen samples were determined using the alpha spectrometry. Different lichens and mosses were collected around the Sobieszewo Island (northern Poland) and investigated for potential use as biomonitors for 210Po and 238U deposition. Mosses and lichens have a high efficiency in capturing 210Po and 238U...

Constraining the history of seawater (234U/238U) is important because this ratio is used to assess the validity of U/ Th ages, and because it provides information about the past rate of physical weathering on the continents. This study makes use of U-rich slope sediments from the Bahamas in an attempt to reconstruct seawater (234U/238U) for the last 800 kyr. For the last 360 kyr, U/Th dating of...

The aim of this work was to determine the concentrations of uranium (234U, 235U, 238U), polonium (210Po) and lead (210Pb) radioisotopes in water samples and to explore the impact of the phosphogypsum stack on the Martwa Wisła waters. The 238U, 210Po and 210Pb concentrations in analyzed water samples reached maximum values of 11.7 ± 0.3, 2.0 ± 0.1 and 3.2 ± 0.1 mBq L-1 and activity ratios were m...

The spatial distribution of (238)U-series radionuclides, specifically 238U, 234U, 230Th and 226Ra, has been determined in stream sediments from Edale, Derbyshire, United Kingdom, to explore the behaviour of U-series radionuclides during weathering. For uranium and thorium, two different extraction methods were used, total dissolution with HNO3/HF in a microwave and leaching with aqua regia. Thi...

Radiochemical results of U isotopes (234U, 235U and 238U) and their activity ratios are reported for well waters as local sources of drinking waters collected from the ten settlements around the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan. The results show that 238U varies widely from 3.6 to 356 mBq/L (0.3-28.7 μg/L), with a factor of about 100. The 238U concentrations in some water samp...

Uranium 236 is a long-lived radionuclide which is created from the naturally occurring trace isotope 235U (0.72% abundance) by thermal neutron capture. This process leads to a natural abundance of 236U in the range from 10-14—10-13 relative to the major 238U isotope (236U/238U). 236U is also created during the process of uranium enrichment for nuclear fuel or weapons, and as a waste product fro...

The activity concentrations of 40K, 232Th, and 238U in the characteristic rocks of the Modane-Aussois region (Western Alps, France) were determined using an HPGe gamma-ray spectrometry system. The activity concentrations of 40K varied from 18 Bqkg-1 (limestone dolomite) to 392 Bqkg-1 (calcschist), while those of 232Th varied from 0.7 Bqkg-1 (limestone dolomite) to 18 Bqkg-1 (calcschist). The ac...

The activity concentrations of 234U and 238U in thermal groundwater, deep well water and river water samples from Central Poland were determined. Concentration of 234U and 238U in the examined waters varied from <0.013 (LLD) to 16.8 mBq/dm3 and from <0.013 (LLD) to 45.5 mBq/dm3 respectively. The highest uranium activity concentrations were measured in the thermal groundwater from Mszczonow and ...