White Oak Lake formerly served as a final settling basin for contaminated waste water discharged from the Oak Ridge National Laboratory. The site, which now serves as an ecological study preserve, covers an area of 44 acres and contains approximately 1,000,000 ft3 of contaminated sediment. The most abundant radionuclide present in the sediment of lacustrine origin is Cs137, 704 ± 35 curies. Concentrations of Cs137 on the sediment were observed to be as high as 77 × 10‐3 µc/g. More than 80% of the Cs137 is associated with the clay fraction of the material, which was found to be predominantly illite. Significant quantities of Cs137 were removed from the material only by treatment with strong acids. Studies of several selected clays showed illite to have a high affinity for Cs137 at levels of the same order of magnitude as those observed in lake bed sediment and that desorption is only accomplished after disruption of the lattice structure.

Burial Ground 4 was opened in February 1951 and closed to routine burial operations in July 1959. The average rate of burial during this period was about 2 1/2 acres per year. Approximately 50% of the buried waste at the site originated at ORNLJ while the remainder was contributed by more than fifty off-site agencies. The site is underlain by the Conasauga shale of Cambrian age. At the burial ground the formation consists mostly of maroon and gray shales interbedded with a few thin limestone lenses. Water-level measurements indicate that the buried waste is in contact with ground water during most periods of the year. Activity was detected in water samples from a number of wells located in areas of low topography where ground water contact with the waste is greatest. Radionuclides were also found in seeps and streams within the area.

As a result of the discharges of large volumes of low-level radioactive liquid wastes to surface stream at the Oak Ridge National Laboratory, large quantities of radionuclides have accumulated in the bottom sediments of White Oak Lake. Ruthenium-106 (1038 c) and cesium-I37 (704 c) account for more than 90 per cent of the total activity now present at the site, while G°Co (152 c), the rare earths (17 c, exclusive of and %k (15 c) make up the remainder. More than half of the activity is associated with the upper 6-in. sediment layer, while progressively smalIer quantities of activity are found with depth. The ruthenium, which is restricted to a small area in the now dry upper lake bed, is partially water soluble; however, its rate of movement through the soil is slow enough so that radioactive decay reduces the concentration of that reaching surface streams to insignificant levels. Most of the 13'Cs occupies highly selective exchange sites on the illitic fraction of the clay in the sediment and can be desorbed only by disruption of the lattice structure. Only a small fraction of the 6oCo in the soil was found to be exchangeable. I t is, therefore, unlikely that any large fraction of the 137Cs or GOCo would move from the area except through erosion of the sediment. About one-half of the "Sr and the rare earths in the sediment appears to be exchangeable, while the other half is in the form of slightly soluble salts. Through leaching by ground water, a slow depletion of strontium from the dry part of the lake bed occurs.The accumulation of radionuclides in the sediments of White Oak Lake illustrates the effectiveness of relatively quiescent bodies of water in concentrating activity in stream beds and in retarding the downstream movement of these materials.

Summary --Zusammenfassung --Résumé Deformation of Rock Salt in Openings Mined for the Disposal of Radioactive Wastes.With the storage of high-level radioaetive waste in salt struetures, unique mine stability problems will oeeur as a result of the elevated temperatures. To prediet flow in rock salt, seale models of salt pillars and their surrounding rooms were fabrieated from eores taken in the Carey salt mine, Lyons, Kansas. Tests were eondueted at temperatures of 22.5 e, 60 o , 100 °, and 200°C for axial loads of 2000, 4000, 6000, 8000, and 10000 psi at ca& temperature. These tests showed that marked inereases oceur in the rates of deformation of salt pillars at high loads and especially at elevated temperatures. For all eombinations of axial loads and temperatures, it was observed that there is initially a high rate of deformation that diminishes with time. Creep rates were found to eontinue to deerease even after more than 3 years of testing. An empirieM relationship between pillar deformarion, stress, temperature, and time was developed from the tests and is expressed as = 0.39.10 -aT T 9'5 o "%0 t -0"70, e = 1.30-:10 -37 T 9"5 a3.0 to.30 where » = strain rate (in./in./hr), « = eumulative deformation (im/in.), T = absolute temperature (°K), o = average pillar stress (psi), and t = time (hr).For eomparative purposes, model pillar tests were eonducted on samples of bedded salt, as welI as deine salt from six different mines in the United States and from the antielinM strueture of the Asse II salt mine in Northeast Germany. In general, the deformational behavior for the various types of salt was similar at room temperature as well as at elevated temperature even though seine variations in the rates of deformation were observed.From model tests it was also observed that greatly aeeelerated rates of deformation will oeeur in exeavated eavities where thin shale beds oeeur in the pillars at the roof and floor interfaees. Sinee the sha!cs serve as frietion redueers, effeetive eonfining stresses in the roof and floor are not transmitted into the pillars; thus the pillars under these eonditions are weaker than where shale partings are not present at the tops and bottoms of the pillars. Verformung von Steinsalz in Schäehten zur Déformation du sei gemme dans des eavités minières pour des déchets radioaetifs.Lots du stockage des déchets de haute radioactivité dans les formations géologiques de se] gemme los températures élevées causent des problèmes spéciaux de stabilité. Pour prévoir l'écoulement dans los formations de sel gemme on a construit des modèles réduits de pi]iers de sel ~ partir de carottes obtenues dans la mine de sel Carey ä Lyons, Kansas. On a fait des essais ä des températures de 22,50 60 °, 100 ° et 200°C, pour des charges axiales de 2000, 4000, 6000, 8000, 10000 psi ä chaque température. Ces essais ont montré que les hautes charges augmentent sensiblement les vitesses de déformation, en particulier aux températures élevées. Pour toutes los combinaisons de charges axiales et de températures, on a observé...

Currently, a few thousand c/year of ruthenium flow onto the bed of former White Oak Lake from the Oak Ridge National Laboratory's intermediate-level waste pits. As the waste water traverses the lake bed a significant portion of the ruthenium is removed from solution. The ruthenium that is not sorbed on the lake-bed soil drains into White Oak Creek, a tributary of the Clinch River.An investigation was made to determine the quantity and distribution of ruthenium in the soil of the lake bed and to identify and define geoghydrological factors affecting the movement of ruthenium through the lake bed. As of February 1962, the lake bed contained approximately 1200 c of ruthenium. The ruthenium is present mainly in two tracts of contamination, covering approximately 10 acres, that coincide roughly with the surface flow of waste over the bed. The highest concentrations of ruthenium occur in the uppermost few in. of the lake bed and about 70 per cent of the activity is in the top 2 ft of soil.The lake bed is underlain by a thin layer of recent lacustrine sediment, several ft of alluvium and the Conasauga shale formation of Cambrian age. Water-level measurements indicate that the depth to ground water varies from < 1 to 5 ft below the surface. The subsurface migration of ruthenium follows closely the paths indicated by water-table contours. The rate of groundwater movement in the upper 2 ft of soil varies from 1 to 5 ft/day, while movement in the material 2-5 ft below the surface ranges from 0.05 to 0.25 ft/day. Thus, the maximum rate at which ruthenium may travel in the upper layers ofsoil is approximately twenty times that of the lower layers.Ruthenium is transported to White Oak Creek by surface water and ground water moving over and through the bed of White Oak Lake. Only a small fraction of the ruthenium is transported by ground water through the lake-bed soil into the creek. The ruthenium moves atsucha slow rate through the soil that radioactive decay reduces the concentration of that reaching the creek by subsurface movement to insignificant proportions. The amount of surface flow and, consequently, the quantity of ruthenium that reaches the creek from the lake bed varies seasonally. During the dry summer months drainage from the waste pits recharges the ground water in the lake bed and thus there is little surface flow and, consequently, little ruthenium that flows into White Oak Creek. However, in the wet winter season surface runoff from the lake bed is high and therefore larger amounts of ruthenium enter White Oak Creek.