41 Matching Results

Search Results

Advanced search parameters have been applied.

Acute skin lesions due to localized ``hot particle`` radiation exposures

Description: Purpose of the studies was to determine incidence and severity of lesions resulting from localized deposition of dose to the skin from small (<0.5 mm) discrete radioactive particles. Hanford mini-swine were exposed to localized doses from 0.2 to over 600 Gy (averaged over 1 cm{sup 2} at 70{mu}m depth) from isotopes having max beta particle energies from about 0.3-3 MeV. Incidence of erythema and scabs (indicating ulceration) were scored routinely for up to 71 days post-irradiation. Responses followed normal probability distributions, and thus, no true threshold could be defined. Ten and 50% incidence rates were deduced using probit analyses. Lowest dose producing 10% incidence was about 1 Gy for exposures to Yb-175 (0.5 MeV max energy) beta particles. Severity of lesions was estimated using diameters and persistence. From preliminary considerations of probability of induction, size, and persistence of acute lesions, a special limit for hot particle exposures in the range of 5-50 Gy may be reasonable, with an action level between about 1 Gy and the limit.
Date: June 1, 1996
Creator: Baum, J.W.; Carsten, A.L.; Kaurin, D.G.L. & Schaefer, C.W.
Partner: UNT Libraries Government Documents Department

Source of process water scandium

Description: Rear face dose rates at the single pass reactors were found to have significantly increased between 1965 and 1967. It was suggested by Battelle-Northwest that an increase in scandium-46 activity may have been a possible cause of the increased dose rates. Battelle-Northwest records showed that considerably more {sup 46}Sc was present in the Columbia River at Richland starting in the summer of 1967 than had been found previously. The ratio of {sup 46}Sc to {sup 65}Zn activity, a correlation which removes seasonal variations in activity, was shown to have increased from 0.1 early in 1967 to l.0 by November of 1967. It was concluded that indeed the {sup 46}Sc release rate from the single pass reactors and the rear face dose es had increased in 1966 and 1967, but not necessarily at the same time {sup 3}. Data presented in the review showed that there had been no changes in parent {sup 45}Sc concentration in the Columbia River between 1962 and 1969, but there had been several changes in water chemistry in 1966 and 1967 which may have contributed to the increased {sup 46}Sc concentration in the reactor effluent. The review document suggested that rear face components be analyzed to verify whether or not the increased {sup 46}Sc concentration in the effluent water was indeed significantly contributing to rear dose rates and that inlet water be analyzed to determine if the increase in {sup 46}Sc was due to the addition of parent {sup 46}Sc with the water treatment chemicals. These analyses have been completed and are presented in this document along with other supporting data.
Date: June 12, 1970
Creator: Larrick, A.P.
Partner: UNT Libraries Government Documents Department

Medical and Health Physics Quarterly Report October, November, andDecember, 1950

Description: A considerable volume of work was accomplished during the past three months in the tracer program, experiments being conducted with At{sup 211}, carrier-free Bi{sup 206}, carrier-free Mn{sup 52}, carrier-free Mo{sup 93,99}, Np{sup 237}, Ta{sup 182} of a fair degree of specific activity, carrier-free Sc{sup 46}, and high specific activity Tm{sup 170}.
Date: February 27, 1951
Creator: Biology, Health and
Partner: UNT Libraries Government Documents Department

Radioisotopes released in DUN liquid effluents

Description: Per your request, we have summarized for both the single-pass reactors and N Reactor the amount of radioisotopes released in DUN reactor liquid effluents. Wherever possible, the sources of the radioisotope and the important parameters which influence the release of the radioisotope have been identified. Because of the great dissimilarities between the two types of reactors, the data are discussed on an individual basis.
Date: March 26, 1970
Creator: Larrick, A. P.; Baker, D. A. & Coffer, C. O.
Partner: UNT Libraries Government Documents Department

Source of process water scandium

Description: An increase in scandium-46 activity has been suggested as a possible cause of K Reactor rear face dose rates. The first investigations were initiated on {sup 46}Sc in 1968 after Environmental Evaluation, BNW, reported the increase in the {sup 46}Sc activity in the Columbia River. The first investigation was to verify whether or not there had been any increase in parent material ({sup 45}Sc) in the Columbia River. The resulting neutron activation data for river samples taken at Vernita during the latter part of 1968 and the first part of 1969 are compared with data obtained in 1962 by Silker. These data show that there was no increase in parent scandium since 1962. There also appears to be no seasonal increase in parent scandium as occurs with several other elements such as zinc. This latter observation (based primarily on the 1962 data) is quite puzzling since the BNW river data from samples taken near Richland show a definite seasonal trend. The BNW data are shown. Scandium-46 analyses of the reactor effluent water were initiated in March 1969 and these data also fail to show any significant seasonal trend of the magnitude shown by the BNW data. The reactor effluent data are also given. Analysis of decontamination solutions obtained during the single-tube, through-reactor decontamination conducted in KE Reactor in October 1969 showed that there were more curies of {sup 46}Sc than any other isotope.
Date: January 20, 1970
Creator: Larrick, A. P.
Partner: UNT Libraries Government Documents Department

Collaborative research on fluidization employing computer-aided particle tracking. Final report

Description: Discussions presented in this report highlight all the important considerations for making particle dynamics measurements using the radioactive active particle tracking methodology. It is seen that the technique makes it possible to obtain data which are not accessible by any other means. Among the advantages of the methods are: (1) It is completely uninvasive, and hence cannot disturb the flow. (2) It can penetrate opaque suspensions. (3) It yields detailed, spatially resolved (subject to resolution limitations) data on mean velocity and density distributions as well as other statistical quantities. Its disadvantages are: (1) It can only provide time averaged data. It cannot provide instantaneous ``snap shots`` of the flow field. (2) It cannot yield information of flows around bubbles, which are of great interest in fluidization theories. (3) It has only modest resolution -- of the order of a two to four percent of the flow field. However, the resolution can be improved by almost an order of magnitude, if long test runs can be used to acquire data of high statistical quality. 4. For data of adequate resolution, long test runs -- several hours and up - are needed. Clearly if used with a clear understanding of its capabilities as well as limitations, the radioactive particle tracking technique can make possible measurements which are not possible by any other method, and contribute significantly to the study of suspension flows.
Date: April 1, 1993
Creator: Chen, M. M.
Partner: UNT Libraries Government Documents Department

Gamma-ray spectrometry of LDEF samples

Description: A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of (sup 22)Na, {sup 46}Sc, {sup 51}Cr, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, and {sup 60}Co. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which have been reported to collect noticeable {sup 7}Be on their leading surfaces. No significant {sup 7}Be was detected in the samples analyzed. The Underground Counting Facility at Savannah River Laboratory (SRL) was used in this work. The facility is 50 ft. underground, constructed with low-background shielding materials, and operated as a clean room. The most sensitive analyses were performed with a 90%-efficient HPGe gamma-ray detector, which is enclosed in a purged active/passive shield. Each sample was counted for one to six days in two orientations to yield more representative average activities for the sample. The non-standard geometries of the LDEF samples prompted the development of a novel calibration method, whereby the efficiency about the samples surfaces (measured with point sources) predicted the efficiency for the bulk sample.
Date: December 31, 1991
Creator: Winn, W. G.
Partner: UNT Libraries Government Documents Department

Atmospheric radionuclide concentrations measured by Pacific Northwest Laboratory since 1961

Description: The atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, radon and thoron decay and the SNAP-9A burn-up ({sup 238}Pu) have been measured at Richland, Washington, since 1961; at Barrow, Alaska, since 1964; and at other stations for shorter periods of time. There has been considerable concern over the health hazard presented by these radionuclides, but it has also been recognized that atmospheric mixing and deposition rates can be determined from their measurement. Therefore, Pacific Northwest Laboratory began the continuous measurement of the atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, and radon and thoron decay. This report will discuss the concentrations of the longer-lived radionuclides (T 1/2 > 12 days). The concentrations of shorter-lived radionuclides measured following Chinese nuclear tests since 1972 are discussed in another report.
Date: March 1, 1981
Creator: Young, J. A. & Thomas, C. W.
Partner: UNT Libraries Government Documents Department

Gamma-ray spectrometry of LDEF samples at SRL

Description: A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of {sup 22}Na, {sup 46}Sc, {sup 51}Cr, {sup 54}Mn, {sup 56}Co, {sup 57}Co, {sup 58}Co, and {sup 60}Co. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which have been reported to collect noticeable {sup 7}Be on their leading surfaces. No significant {sup 7}Be was detected in the samples analyzed. The Underground Counting Facility at Savannah River Laboratory (SRL) was used in this work. The facility is 50 ft. underground, constructed with low-background shielding materials, and operated as a clean room. The most sensitive analyses were performed with a 90%-efficient HPGe gamma-ray detector, which is enclosed in a purged active/passive shield. Each sample was counted for one to six days in two orientations to yield more representative average activities for the sample. The non-standard geometries of the LDEF samples prompted the development of a novel calibration method, whereby the efficiency about the samples surfaces (measured with point sources) predicted the efficiency for the bulk sample.
Date: July 22, 1991
Creator: Winn, W. G.
Partner: UNT Libraries Government Documents Department

Selected radioisotopes` concentrations in integrated reactor effluent water samples

Description: This document contains the results of weekly sampling of various isotope concentrations from effluent water at the 100 area at Hanford from July 1962 to February 1965. Compiled data in microcuries/milliliter are given. Each sampling records the concentrations of iodine-131, phosphorus-32, zinc-65, scandium-46, chromium-51, and cobalt-60. Records prior to October 8, 1962 also contain information on strontium-90, cesium-137, zirconium-95, ruthenium-103, ruthenium-106, and strontium-89. These last records are all from F reactor samples.
Date: December 1, 1962
Creator: Jackson, P. O.
Partner: UNT Libraries Government Documents Department

Environmental status of the Hanford reservation for 1970

Description: Data are summarized on the radioactivity in environmental samples collected from various locations within the Hanford plant boundaries during 1970. Data are included on the content of /sup 90/Sr, /sup 32/P, /sup 46/Sc, /sup 51/ Cr, /sup 65/Zn, /sup 131/I, /sup 2 4/Na and tritium in samples of water from the Columbia River; the total BETA activity in samples of drinking water; the total alpha and BETA activity in samples of surface waters; the radioactivity in tissue samples from waterfowl, game birds, deer, and small mammals feeding on the area; the total BETA activity and /sup 131/I content in samples of surface air; and the total alpha , BETA , and gamma activity in samples of air filters from various locations. (CH)
Date: June 1, 1972
Creator: Bramson, P.E. (ed.)
Partner: UNT Libraries Government Documents Department

Research in Nuclear Physics. Progress Report No. 8

Description: A second set of quadrupole magnets was installed in the cyclotron close to the vacuum chamber in order to increase the beam intensity. The pole pieces of the 20in. analyzing magnet were trimmed. Scattering of 19Mev alpha particles by C/sup 12/, 0/sup 16/, and S/sup 32/ was investigated at various angles. Beta- gamma directional correlations of allowed as well as forbidden beta transitions in the decay of Na/sup 24/, Co/sup 60/, and Sc/sup 46/ were investigated. Results of an experimental investigation of the beta-gamma directional correlation and the spectral shape of the first-forbidden spectra of K/sup 42/ and Au/sup 198/ are presented. Polarization-directional correlation measurements were performed on the Ar/sup 38/ cascade gamma rays following Cl/sup 38/ decay in order to determine the parities of the levels and to remove some of the ambiguity of the directional correlation spin assignments. Nonconservation of parity in beta decay, circular polarization of gamma rays following beta decay, and polarization of conversion electrons following beta decay are considered. The transverse polarization of beta particles in the first-forbidden beta decay of Au/ sup 198/ was measured. A 4 pi beta spectrometer for the study of beta and gamma radiations associated with the decay of short-lived radio-nuclides has been constructed. The study of the 119-kev transition in the decay of the 4.9 hr In/ sup 110m/ has been continued. (For preceding period see AECU-3515.) (W.D.M.)
Date: June 15, 1958
Partner: UNT Libraries Government Documents Department

Recovery and purification of nickel-63 from HFIR-irradiated targets

Description: The production of large quantities of high-specific-activity {sup 63}Ni (>10 Ci/g) requires both a highly enriched {sup 62}Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at {sup 51}Cr, and scandium, present as {sup 46}Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.
Date: June 1, 1993
Creator: Williams, D. F.; O`Kelley, G. D.; Knauer, J. B.; Porter, C. E. & Wiggins, J. T.
Partner: UNT Libraries Government Documents Department

Collaborative research on fluidization employing computer-aided particle tracking

Description: This report covers the sixth quarter of the subject contract. The primary objective of this quarter was modifying the software and testing the hardware of the transportable computer-aided particle tracking apparatus to be used at the Morgantown Energy Technology Center. While the data acquisition programs have been described in the last report, the program names were changed and the method for input to these programs was modified for convenient use. The hardware settings and arrangement were checked in order to obtain the optimum operating condition. 4 figs.
Date: January 1, 1990
Creator: Chen, M.M.
Partner: UNT Libraries Government Documents Department

Use of tracers in materials-holdup study

Description: Holdup measurements of special nuclear materials in large processing facilities offer considerable challenges to conventional nondestructive-assay techniques. The use of judiciously chosen radioactive tracers offer a unique method of overcoming this difficulty. Three examples involving the use of /sup 46/Sc and fission products from activated uranium in large-scale experimental studies of uranium holdup are discussed. A justification for the method and its advantages along with examples of successful applications of this technique for large-sale experimental studies are presented.
Date: January 1, 1983
Creator: Pillay, K.K.S.
Partner: UNT Libraries Government Documents Department

Mechanisms of impurity diffusion in rutile

Description: Tracer diffusion of /sup 46/Sc, /sup 51/Cr, /sup 54/Mn, /sup 59/Fe, /sup 60/Co, /sup 63/Ni, and /sup 95/Zr, was measured as functions of crystal orientation, temperature, and oxygen partial pressure in rutile single crystals using the radioactive tracer sectioning technique. Compared to cation self-diffusion, divalent impurities (e.g., Co and Ni) diffuse extremely rapidly in TiO/sub 2/ and exhibit a large anisotropy in the diffusion behavior; divalent-impurity diffusion parallel to the c-axis is much larger than it is perpendicular to the c-axis. The diffusion of trivalent impurity ions (Sc and Cr) and tetravalent impurity ions (Zr) is similar to cation self-diffusion, as a function of temperature and of oxygen partial pressure. The divalent impurity ions Co and Ni apparently diffuse as interstitial ions along open channels parallel to the c-axis. The results suggest that Sc, Cr, and Zr ions diffuse by an interstitialcy mechanism involving the simultaneous and cooperative migration of tetravalent interstitial titanium ions and the tracer-impurity ions. Iron ions diffused both as divalent and as trivalent ions. 8 figures.
Date: January 1, 1984
Creator: Peterson, N.L. & Sasaki, J.
Partner: UNT Libraries Government Documents Department