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Relationships among plutonium contents of soil, vegetation, and animals collected on and adjacent to an integrated nuclear complex in the humid southeastern United States

Description: Twenty-three representative sampling locations in and adjacent to the Savannah River Plant (SRP) site were selected to obtain information on Pu movement in the food chain under southeastern U. S. environmental conditions. Soil, a resuspendible fraction of the soil, honeysuckle (Lonicera japonica), and camphor weed (Heterotheca subaxillaris) were collected at each location. Grasshoppers and cotton rats (Sigmodon hispidus) were collected at some locations. The soil concentrations at the selected locations ranged from 1.5 fCi/g to 171 fCi/g, and alpha percentages of $sup 238$Pu ranged from 2 to 66. The concentration of plutonium in the vegetation and on the leaves ranged from 0.17 to 76.1 fCi/g, and the alpha percentages of $sup 238$Pu, from 3 to 61. The concentration of plutonium in cotton rats and grasshoppers ranged from 0.07 to 3.58 fCi/g, and the alpha percentages of $sup 238$Pu ranged from 22 to 80. Comparisons among the Pu values of the vegetation, soil, and resuspendible fractions suggest the use of a proposed resuspendible measurement technique as a monitoring method to indicate subtle changes in the Pu concentration of the soil surface that are not detectable by routine soil sampling. Although the $sup 238$Pu data in the various ecosystem components were not conclusive, they support evidence that there is an apparent increase in the biological availability of $sup 238$Pu relative to the $sup 239$' $sub 240$ in the environment. The Pu concentrations of ecosystem components decreased as the distance from the reprocessing plants increased. (auth)
Date: January 1, 1975
Creator: McLendon, H. R.; Stewart, O. M.; Boni, A. L.; Corey, J. C.; McLeod, K. W. & Pinder, J. E.
Partner: UNT Libraries Government Documents Department

Plutonium in Atlantic coastal estuaries in the southeastern United States

Description: A survey was made to begin to provide baseline information on the Pu distribution of representative estuarine and coastal areas of the southeastern United States. Sediments and marsh grass (Spartina) were collected and analyzed from three locations within a tidal marsh. In three estuaries (Savannah, Neuse, and Newport), the suspended particulate matter (1 $mu$m and greater) was filtered from waters with different salinities, and the plutonium content of the particulates determined. The Savannah River estuary, in addition to fallout Pu, has received up to 0.3 Ci of Pu from the Savannah River Plant (SRP) of the U. S. Energy Research and Development Administration. The SRP plutonium has a variable isotopic composition that can influence Pu isotopic ratios in the estuarine system. The other estuaries do not have nuclear installations upstream. Data are included on the content of $sup 238$Pu, $sup 239$Pu, and $sup 240$Pu in sediments and marsh grass of the Savannah River estuary. (CH)
Date: January 1, 1975
Creator: Hayes, D. W.; LeRoy, J. H. & Cross, F. A.
Partner: UNT Libraries Government Documents Department

Confinement of airborne radioactivity. Progress report, January--December 1974

Description: Several commercial activated carbons, marketed for iodine removal in reactor off-gas cleanup systems, were evaluated for iodine penetration at elevated temperatures (4 hr at 180$sup 0$C), and the penetration data varied widely. Subsequent chemical analysis of the samples indicated a strong correlation between the atom ratio of iodine to potassium (I/K) in the carbon and the high-temperature performance data. Iodine penetration tests were also performed on several carbons in an intense gamma radiation field (greater than 10$sup 7$ rads/hr). Test data show that carbons intentionally exposed to high concentrations of DOP aerosol performed as well as unexposed carbons. Studies of the rate of evaporation of elemental iodine from aqueous solutions indicated that significant quantities of I$sub 2$ might be expected to become airborne within a short period of time (5 hr) after release to open ponds. Addition of sodium thiosulfate to the solution substantially reduced the evaporative loss of iodine; however, the effects of high-intensity radiation fields on iodine-thiosulfate solutions remain to be evaluated. Small HEPA filters containing filter media of the type used in the Savannah River confinement system were exposed to reactor building air and a high-intensity radiation field. Following this exposure, they were tested for flow performance under simulated accident conditions. Radiation exposure slightly impaired the performance of new filters and improved the performance of service-aged filters. Service aging effects on filter performance were far more significant than radiation effects. (auth)
Date: January 1, 1974
Creator: Dexter, A.H.; Evans, A.G. & Jones, L.R.
Partner: UNT Libraries Government Documents Department

Dissolution of PuO$sub 2$ with cerium(IV) and fluoride promoters

Description: Ce(IV) in low concentrations is an effective promoter of PuO$sub 2$ dissolution in nitric acid solutions of approximately 3 to 6M. However, stoichiometric quantities of Ce(IV) are required for complete dissolution, and hydrothermal precipitation of CeO$sub 2$ is a potential problem at low acidities. Dissolution proceeds with oxidation of Pu(IV) to Pu(VI) with a corresponding reduction of Ce(IV). When an excess of Ce(IV) is present, the dissolution rate depends on Ce(IV) concentration below approximately 0.1M Ce(IV); above this concentration, the rate becomes fairly constant. Increased PuO$sub 2$ sintering temperature markedly reduces the dissolution rate in 4M HNO$sub 3$-0.15M Ce(IV). Preliminary results indicate stainless steel corrosion rates in Ce(IV)-HNO$sub 3$ solutions increase to significant values with increasing Ce(IV) concentration. In HNO$sub 3$-KF, the PuO$sub 2$ dissolution rate increases rapidly as the nitric acid and fluoride concentrations increase. The rate is decreased by increased PuO$sub 2$ sintering temperature and the presence of cationic species such as UO$sub 2$$sup 2+$ and Fe$sup 3+$, which complex fluoride. Dissolution is much more rapid in HNO$sub 3$-KF solutions than in HNO$sub 3$-Ce(IV). Mixed KF and Ce(IV) in certain mole ratios in 8M HNO$sub 3$ gives more rapid dissolution than with Ce(IV) or KF alone; more Ce(IV) retards dissolution. In HNO$sub 3$-0.05M Ce(IV)--0.1M KF, the dissolution rate increases as HNO$sub 3$ concentration increases; below 6M HNO$sub 3$, the mixed system containing 0.05M Ce(IV)-0.1M KF is less effective than HNO$sub 3$-Ce(IV) or HNO$sub 3$-KF. Ruthenium, present in irradiated PuO$sub 2$, catalytically reduces Ce(IV) in nitric acid; thus, Ce(IV) will be ineffective for irradiated PuO$sub 2$-UO$sub 2$ fuel. In view of the ruthenium problem, HNO$sub 3$-F$sup -$ solutions appear most promising for breeder fuel processing. Nitric acid solutions containing Ce(IV) and Ce(IV)- F$sup -$ mixtures may be most useful for dissolving unirradiated PuO$sub 2$ and UO$sub 2$-PuO$sub 2$ materials, ...
Date: October 1, 1975
Creator: Harmon, H.D.
Partner: UNT Libraries Government Documents Department

Environmental control procedures at the Savannah River Plant

Description: New environmental control activities in the past year at SRP have included improved control and reporting procedures for chemical spills, reclamation of high-value scrap from wastes, new disposal methods for solid wastes not suitable for the sanitary landfill, improved oil containment, and reduction of sediment discharges to on-plant streams. Interdepartmental committees provide the primary routes for planning and coordinating environmental protection throughout SRP. An improved site-use coordination procedure, developed and implemented by ERDA-SR, has provided more effective control and communication pertaining to activities of the several organizations actively using the 300-square-mile SRP site. (auth)
Date: January 1, 1975
Creator: Sheldon, E.B.
Partner: UNT Libraries Government Documents Department

Helium bubbles at grain boundaries of high-density $sup 238$PuO$sub 2$ shards

Description: Hydroxide- and oxalate-base $sup 238$PuO$sub 2$ shards that were sintered to high density at 1200 or 1600$sup 0$C and then aged for 6 months or more exhibited grain-boundary gas bubbles due to agglomeration of alpha-decay helium when heated to 1200$sup 0$C and above. Conditions for bubble formation depended markedly on shard microstructure; large-grained shards with few large residual sintering pores formed gas bubbles at lower temperatures than small- grained shards with many pores. This behavior was especially apparent in oxalate- base $sup 238$PuO$sub 2$, in which small-grained shards resisted bubble formation to above 1500$sup 0$C; small-grained hydroxide-base shards with less internal porosity than oxalate-base shards formed bubbles at lower temperatures. Helium is apparently released from aged $sup 238$PuO$sub 2$ shards at high temperatures by bulk diffusion within grains to the grain boundaries, where bubbles are formed and interconnect into networks which permit helium escape. It is postulated that helium is released by grain boundary diffusion at temperatures below thresholds for grain boundary bubble formation. Small grain size and high residual porosity within grains inhibit the formation of the grain-boundary gas bubbles by reducing the concentration of helium gas at the grain boundaries. (10 fig) (auth)
Date: January 1, 1975
Creator: McDonell, W.R.; Sheenan, J.E. & Sisson, R.D.
Partner: UNT Libraries Government Documents Department

Neptunium behavior in solvent extraction of uranium at Savannah River Plant

Description: The solvent extraction behavior of neptunium in the processing of irradiated natural uranium (Purex process) and irradiated enriched uranium (HM process) at Savannah River was studied in the laboratory. Conditions were demonstrated for extracting neptunium in the first solvent extraction contactor of each process, and two methods were developed for partitioning neptunium from uranium in the HM process. (auth)
Date: September 1, 1961
Creator: Henry, H E; Karraker, D G & Schlea, C S
Partner: UNT Libraries Government Documents Department

Neutron radiographic detection limits of fluids in metal pipes

Description: Thermal neutron radiography has been used to image thin films of various fluids in thick-walled high-pressure process pipes. A 3.5 x 10$sup 6$ n/(cm$sup 2$-sec) thermal neutron beam and standard transfer imaging techniques were used to provide radiographs of the fluid-bearing pipes. In addition, a computer graphics procedure was developed which simulated the neutron radiographs; this method permitted examination of some fluid-pipe configurations not studied experimentally. Actual pipe outer dia ranged from $sup 1$/$sub 4$ to $sup 9$/ $sub 16$ in. (OD/ID = 3), but the graphics method was used for some cases outside this range. Fluids in the thermal cross section range 0.29 cm$sup -1$ less than or equal to $Sigma$/sub th//sup f/ less than or equal to 3.47 cm$sup - 1$ were examined for pipes with 0.099 cm$sup -1$ less than or equal to $Sigma$/ sub th//sup p/ less than or equal to 1.15 cm$sup -1$. For $Sigma$/sub th//sup f/ greater than $Sigma$/sub th//sup p/, the smallest measured film thickness t/sub s/ varied 0.006 to 0.040 in. with decreasing $Sigma$/sub th//sup f/; a semiempirical model described t/sub s/ = t/sub r/ + t/sub a/, where t/sub r/ corresponded to resolution and t/sub a/ depended on the bulk attenuation strength of the fluid. For $Sigma$/sub th//sup f/ less than $Sigma$/sub th//sup p/, part of the fluid film t/sub m/ was masked by the pipe. The calculated physical film thickness t/sub p/ = t/sub a/ + t/sub m/ ranged from 0.003 to 0.035 in. for smallest detected fluid films. Detection of low $Sigma$/sub th/ fluids was improved as much as 60 percent when the pipes were tilted 60$sup 0$ toward the neutron beam. Other options for improved detection were investigated using simulated radiographs. (auth)
Date: January 1, 1975
Creator: Winn, W.G.
Partner: UNT Libraries Government Documents Department

100 mg $sup 251$Cf activation analysis facility at the Savannah River Laboratory

Description: The $sup 252$Cf Activation Analysis Facility at the Savannah River Laboratory (SRL) is used routinely for multielement analyses of a wide variety of solid and liquid samples (e.g., metal alloys, fly ash and other airborne particles, rocks, and aqueous and nonaqueous solutions). An automated absolute activation analysis technique, developed to use neutron transport codes to calculate multienergy group neutron spectra and fluxes, converts counting data directly into elemental concentrations expressed in parts per million. The facility contains four sources of $sup 252$Cf totaling slightly over 100 mg. A pneumatic ''rabbit'' system permits automatic irradiation/decay/counting regimes to be performed unattended on up to 100 samples. Detection sensitivities of less than or equal to 400 ppb natural uranium and less than or equal to 0.5 nCi/g for $sup 239$Pu are observed. Detection limits for over 65 elements have been determined. Over 40 elements are detectable at the one part per million level or less. Overall accuracies of +- 10 percent are observed for most elements. (auth)
Date: January 1, 1975
Creator: MacMurdo, K.W. & Bowman, W.W.
Partner: UNT Libraries Government Documents Department

Acceleration techniques for response matrix methods

Description: Application of the power iteration method to the multigroup response matrix equations reduces them to a series of one-group problems. Applying acceleration techniques to each of these monoenergetic problems results in substantial reductions in computational effort. The use of point over-relaxation methods in the solution of these equations is described. Over-relaxation is also applied to the outer-iteration eigenvalue and source estimations with considerable success. 10 references. (auth)
Date: January 1, 1975
Creator: Sicilian, J.M. & Pryor, R.J.
Partner: UNT Libraries Government Documents Department

Concentration of aqueous radioactive waste with wiped-film evaporators

Description: Tests at the Savannah River Laboratory with two small wiped-film evaporators show that synthetic alkaline (Purex) waste can be converted to a free- flowing slurry that solidifies on cooling to ambient temperature. The desired concentration can be obtained in one pass rather than the several passes required with the bent-tube evaporators presently used at the Savannah River Plant. (auth)
Date: January 1, 1975
Creator: Goodlett, C.B.
Partner: UNT Libraries Government Documents Department

Status of measured neutron cross sections of transactinium isotopes for thermal reactors

Description: Experimentally determined neutron cross sections, resonance parameters, and the average number of neutrons per fission for neutron-induced fission of actinide nuclides in the production chains associated with thermal and near- thermal reactors are summarized and compared with user requests for experimental data. The primary fertile and fissile isotopes $sup 232$Th, $sup 233$U, $sup 235$U, $sup 238$U, and $sup 239$Pu are excluded from this survey. Integral data, i.e., spectrum-averaged thermal cross sections and resonance integrals, are included, but the emphasis is placed on energy-dependent differential cross sections because of their general utility with any specified neutron energy spectrum. Included with the data summaries are an extensive survey of the literature through August 1975, brief descriptions of measurements known to be in progress or firmly planned for the immediate future, and recommendations for needed measurements. (3 figures, 5 tables) (auth)
Date: January 1, 1975
Creator: Benjamin, R.W.
Partner: UNT Libraries Government Documents Department

Surface effects on tritium diffusion in materials in a radiation environment

Description: Tritium transport and distribution in a material are controlled by chemical potential and thermal gradients and cross-coupling to impurities and defects. Surfaces influence tritium diffusion by acting as sources and sinks for defects and impurities, and surface films restricting tritium transfer between the solid and surrounding fluids. Radiation directly affects boundary processes such as dissociation or adsorption, may erode a surface film or the surface itself, and introduces defects and impurities into the solid by radiation damage, transmutation, or ion implantation, thereby modifying tritium transport within the solid and its transfer across external interfaces. There have been no definitive investigations of these effects, but their practical significance has been demonstrated in tritium release or absorption studies with stainless steel, Zircaloy, niobium, and other materials. (auth)
Date: January 1, 1975
Creator: Caskey, G.R. Jr.
Partner: UNT Libraries Government Documents Department

Thermal conductivity of $sup 238$PuO$sub 2$ powder, intermediates, and dense fuel forms

Description: The thermal conductivities of porous $sup 238$PuO$sub 2$ powder (calcined oxalate), milled powder, and high-density granules were calculated from direct measurements of steady-state temperature profiles resulting from self- heating. Thermal conductivities varied with density, temperature, and gas content of the pores. Errors caused by thermocouple heat conduction were less than 5 percent when the dimensions of the thermal conductivity cell and the thermocouple were properly selected. (auth)
Date: October 1, 1975
Creator: Bickford, D.F. & Crain, B. Jr.
Partner: UNT Libraries Government Documents Department

Fabrication of granule and pellet heat sources from oxalate-based $sup 238$PuO$sub 2$

Description: Suitable fuel forms for radioisotopic thermoelectric generators are granules of high internal density (greater than 95 percent of theoretical) or geometric shapes (80 to 90 percent dense) such as pellets or spheres. Both forms can be made from calcined $sup 238$Pu(III) oxalate. The conditions for processing PuO$sub 2$ are controlled during fuel form fabrication to ensure pellet integrity; to control density, grain size, and porosity distribution; and to minimize the fraction of potentially respirable fines. The competing phenomena of expansion caused by radiation damage (including helium generation from radioactive decay of plutonium) and shrinkage caused by sintering must be controlled to assure dimensional stability. The variation of microstructure and related physical properties with process parameters is discussed. (auth)
Date: January 1, 1975
Creator: Bickford, D.F. & Rankin, D.T.
Partner: UNT Libraries Government Documents Department

SOLVEX: a computer program for simulation of solvent extraction processes

Description: SOLVEX is a FORTRAN IV computer program that simulates the dynamic behavior of solvent extraction processes conducted in mixer-settlers and centrifugal contactors. Two options permit terminating dynamic phases by time or by achieving steady state, and a third option permits artificial rapid close to steady state. Thus the program is well suited to multiple phases of dynamic problems and multiple input of steady state problems. Changes from the previous problem are the only inputs required for each succeeding problem. Distribution data can be supplied by two-variable third-power polynomial equations or by three- variable tables in any one of 16 different combinations involving phase concentrations or distribution coefficients (ratio of phase concentrations) or their logarithms. (auth)
Date: September 1, 1975
Creator: Scotten, W.C.
Partner: UNT Libraries Government Documents Department

Equilibrium distribution of uranyl nitrate between nitric acid and 7.5 vol % TBP

Description: The distribution of nitric acid and uranyl nitrate between aqueous solution and 7.5 vol percent tributyl phosphate in normal paraffin diluent was measured at 23, 45, and 60$sup 0$C. The data are consistent with behavior expected from theory and with previously published data. The data have been used to design a solvent extraction flowsheet for recovery of enriched uranium. (auth)
Date: October 1, 1975
Creator: Thompson, M.C.; Murphree, B.E. & Shankle, R.L.
Partner: UNT Libraries Government Documents Department

Clam survival in chlorinated water

Description: Applications of 10 to 40 ppM chlorine were ineffective in control of Asiatic clams that had colonized the suction well of a cooling water pump for one of the Savannah River production reactors. Accumulated mud on the floors and walls of the basin protected large numbers of clams from lethal chlorine exposures. After clams were removed from chlorine exposures of 9, 17, 25, and 54 hours, respective survivals after seven days in a recovery chamber were 97 percent, 84 percent, 47 percent, and 10 percent. Of the clams that were protected by mud during the entire test (54 hours), 65 percent were alive after seven days in the recovery chamber. (auth)
Date: April 30, 1976
Creator: Tilly, L.J.
Partner: UNT Libraries Government Documents Department