The Distribution of Natural Radionuclides on Fracture Surfaces in Palmottu Analogue Study Site in SW Finland

Matrix Diffusion — Evidences from Natural Analogue Studies at Palmottu in SW Finland

“…This was not expected because the easily dissolvable phase that covered the mixture of kaolinite and quartz separated from the U containing calcite (sample 221/DH331) the 234 U/ 238 U activity ratio was 6.05. The amounts of easily dissolvable U in these samples were 2626 and 398 μg/g, respectively [15].…”

“…The residue left after the extractions was dissolved in a HF-HN0 3 -HC1 mixture. The extraction procedure has been described earlier [15].…”

On the Role of α-Recoil in Uranium Migration - Some Findings from the Palmottu Natural Analogue Site, SW Finland

“…Absolute concentrations and activity ratios for the source phase and target phase. Numbers in parentheses are laboratory codes and refer to the same samples in other publications [4,8] …”

“…Isotopie fractionation of U, resulting in U-234 enrichment takes place in natural waters, and it has been universally linked to α-recoil effects in the natural radioactive decay series [1,2], Similar enrichment has also been observed across phase boundaries in rock material [1,3,4,5], of which good experimental evidence can be found in [3]. In contrast, clear U-234 depletion was observed in a deposited U-rich phases at the natural analogue site at Palmottu [6], As compared to waters, recoil transfer within rock material has been much less discussed, and discussions have been mostly qualitative.…”

“…It must therefore be regarded as a preliminary concept study. Thus, it is useful that two of the samples are calcites for which the USD based dating has already been done [4,8],…”