1,934 Matching Results

Search Results

Advanced search parameters have been applied.

Alpha-emitters for medical therapy workshop

Description: A workshop on ``Alpha-Emitters for Medical Therapy`` was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference.
Date: December 31, 1996
Creator: Feinendegen, L.E. & McClure, J.J.
Partner: UNT Libraries Government Documents Department

Lung cancer risk of low-level exposures to alpha emitters: critical reappraisal and experiments based on a new cytodynamic model

Description: Ecologic U.S. county data suggest negative associations between residential radon exposure and lung cancer mortality (LCM)-inconsistent with clearly positive associations revealed by occupational data on individual miners, but perhaps explained by competing effects of cell killing vs. mutations in alpha-exposed bronchial epithelium. To assess the latter possibility, a biologically based �cytodynamic 2-stage� (CD2) cancer-risk model was fit to combined 1950-54 age- specific person-year data on lung cancer mortality (LCM) in white females of age 40+ y in 2,821 U.S. counties (-90% never-smokers), and in 5 cohorts of underground miners who never smoked. New estimates of household annual average radon exposure in U.S. counties were used, which were found to have a significant negative ecologic association with 1950-54 LCM in U.S. white females, adjusted for age and all subsets of two among 21 socioeconomic, climatic and other factors considered. A good CD2 fit was obtained to the combined residential/miner data, using biologically plausible parameter values. Without further optimization, the fit also predicted independent inverse dose-rate effects shown (for the first time) to occur in nonsmoking miners. Using the same U.S. county-level LCM data, a separate study revealed a positive ecologic association between LCM and bituminous coal use in the U.S., in agreement with epidemiological data on LCM in women in China. The modeling results obtained are consistent with the CD2-based hypothesis that residential radon exposure has a nonlinear U-shaped relation to LCM risk, and that current linear no-threshold extrapolation models substantially overestimate such risk. A U-shaped dose-response corresponds to a CD2-model prediction that alpha radiation kills more premalignant cells than it generates at low exposure levels, but not at higher levels. To test this hypothesis, groups of Japanese medaka (ricefish minnows) were exposed for 10 to 14 weeks to different concentrations of aqueous radon; histological and quantitative-morphometry analysis of proliferative (premalignant) ...
Date: February 20, 1999
Creator: Bogen, K T
Partner: UNT Libraries Government Documents Department

Definition and means of maintaining the effluent stack monitors portion of the PFP safety envelope

Description: The Effluent Stack Monitors ensure that the release of alpha emitting radionuclides to the environment via the building exhaust stacks is continuously monitored and alarms are initiated if the release exceeds identified limits. This document defines the safety envelope for the Effluent Stack Monitors and identifies the operability requirements, components, and procedures which ensure this safety envelope is maintained.
Date: January 21, 1997
Creator: Sullivan, P.J.
Partner: UNT Libraries Government Documents Department

45-Day safety screen results for Tank 241-B-112, auger samples 95-AUG-014 and 95-AUG-015

Description: Two auger samples from Tank 241-B-112 (B-112) were received in the 222-S Laboratories and underwent safety screening analyses, consisting of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and total alpha activity. All results for all analyses (DSC, TGA, and total alpha) were within the safety screening notification limits specified in the Tank Characterization Plan (TCP). No notification nor secondary analyses were required. Tank B-112 is not part of any of the four Watch Lists.
Date: May 1, 1995
Creator: Conner, J.M.
Partner: UNT Libraries Government Documents Department

Alpha contamination assessment for D&D activities: Technology overview

Description: Instruments based on the principle of Long-Range Alpha Detection (LRAD) detect the ions created in ambient air by Ionizing radiation, particularly alpha radiation, interacting with air molecules. Using either an electrostatic field or forced convection, these ions can be transported to a detection grid where the ions produce a small current that is measured with a sensitive electrometer. LRAD-based instruments can give separate, simultaneous measurements of alpha-emitting solids and inert radioactive gases such as radon. LRAD-based instruments assess surface contamination on an entire object or large surface area in a single, rapid measurement, including relatively inaccessible areas such as interior surfaces of pipes and process equipment. The LRAD concept is well proven and has been developed into a range of different radiation detection devices. This paper presents an overview of the technology, while several associated papers explore specific applications in greater detail.
Date: February 1, 1996
Creator: Conaway, J.G.; Rawool-Sullivan, M.W. & MacArthur, D.W.
Partner: UNT Libraries Government Documents Department

A fieldable instrument for waterborne radionuclide detection

Description: In monitoring effluent leaving its sites, US DOE assays for alpha- emitting radionuclides (U, transuranics) to ensure compliance with regulatory limits. Because alpha emissions can only by detected over a short range in water ({approximately}40{mu}m), the conventional approach is to collect samples for processing in a central laboratory; a time-consuming and cost procedure ensues to separate and measure the radionuclides. Because of the sporadic nature of sampling processes, there is the possibility that a release may go undetected. We are addressing this issue by a developing a real-time, field- deployable instrument which incorporates a proprietary film that selectively binds radionuclides from dilute aqueous samples. By combining the film with an appropriate alpha spectrometer, we have developed a fieldable system that can operate as an autonomous monitor in a batch or continuous manner. Laboratory results to date have been encouraging. Positive identification of U and Pu has been made by resolving the energy spectrum of emitted alphas. Sensitivity for U is at the 10 part per trillion level (15 femtocuries per liter).
Date: December 31, 1996
Creator: Barshick, C.M.; Turner, M.L.; Smith, D.H. & Patch, K.D.
Partner: UNT Libraries Government Documents Department

HALF-LIVES OF LONG-LIVED A-DECAY, B-DECAY, BB-DECAY AND SPONTANEOUS FISSION NUCLIDES.

Description: In his review of radionuclides for dating purposes, Roth noted that there were a large number of nuclides, normally considered ''stable'' but which are radioactive with a very long half-life. Roth suggested that I review the data on the half-life values of these long-lived nuclides for a discussion session at the next meeting. These half-life values for long-lived nuclides include those due to various decay modes, {alpha}-decay, {beta}-decay, electron capture decay, {beta}{beta}-decay and spontaneous fission decay. This report is preliminary but will provide a quick overview of the extensive table of data on the recommendations from that review.
Date: June 29, 2001
Creator: HOLDEN,N.E.
Partner: UNT Libraries Government Documents Department

Alpha decay studies of {sup 189}Bi{sup m}, {sup 190}Po and {sup 180 }Pb using a rapidly rotating recoil catcher wheel system

Description: The {alpha} decays of very neutron deficient nuclei near the Z = 82 closed proton shell are of interest because they provide us with structure information that is relevant with regard to the shell model. We used a rapidly rotating recoil catcher wheel system to study the {alpha} decays of {sup 189}Bi{sup {ital m}}, {sup 190}Po, and {sup 180}Pb. The system works as follows. Recoils from the back of the target, after passing through an Al degrader placed behind the target, are stopped in 300-{mu}g/cm{sup 2} Al catcher foils fixed at the edges of the wheel. These are inclined at an angle of 20 degrees with respect to the beam to maximize the catcher efficiency while keeping the thickness that {alpha} particles must travel in order to emerge of the Al foil to a minimum. This arrangement results in an effective thickness of {approx} 900 {mu}g/cm{sup 2} for recoils, but only 150 {mu}g/cm{sup 2} for the emitted {alpha} particles. Stopped recoils are then rotated between an array of 6 Si detectors in series (solid angle of 8% of 4{pi}). Half-life information can be obtained by determining the difference in counts between the detectors. This instrument has proven to be an effective tool for the study of nuclei far from stability with half-lives in the range of 1-50 ms.
Date: September 1, 1996
Creator: Batchelder, J.C.; Toth, K.S. & Moltz, D.M.
Partner: UNT Libraries Government Documents Department

Measurement of radionuclides using ion chromatography and flow-call scintillation counting with pulse shape discrimination: Topical report, September 15, 1996--October 3, 1996, Tasks 1.11, 1.12 and 1.13

Description: Several flow-cell radiation detector systems are commercially available for quantification of aqueous radioactive solutions. These systems do not use the technique of pulse shape discrimination to identify the incident radiation and therefore are limited in environmental characterization application when coupled to an ion chromatography system. The advantages of the pulse shape discriminating flow-cell detector over the commercially available systems include: (1) lower minimum detectable activity for alpha radiation, (2) reduced radiological interferences that may exist between co-eluted alpha- and beta-emitting radionuclides, and (3) possible isotopic information from the ion chromatography system. For Tasks 1.1.1 and 1.1.2 of this project, several scintillation materials were investigated for pulse shape (alpha and beta) discrimination capabilities and the best candidate material was optimized. In addition, the following detector properties were also optimized: scintillator particle size, flow-cell tubing type, and electromagnetic as well as optical crosstalk between the photomultiplier tubes.
Date: April 1, 1997
Partner: UNT Libraries Government Documents Department

Hanford high level waste: Sample Exchange/Evaluation (SEE) Program

Description: The Pacific Northwest Laboratory (PNL)/Analytical Chemistry Laboratory (ACL) and the Westinghouse Hanford Company (WHC)/Process Analytical Laboratory (PAL) provide analytical support services to various environmental restoration and waste management projects/programs at Hanford. In response to a US Department of Energy -- Richland Field Office (DOE-RL) audit, which questioned the comparability of analytical methods employed at each laboratory, the Sample Exchange/Exchange (SEE) program was initiated. The SEE Program is a selfassessment program designed to compare analytical methods of the PAL and ACL laboratories using sitespecific waste material. The SEE program is managed by a collaborative, the Quality Assurance Triad (Triad). Triad membership is made up of representatives from the WHC/PAL, PNL/ACL, and WHC Hanford Analytical Services Management (HASM) organizations. The Triad works together to design/evaluate/implement each phase of the SEE Program.
Date: August 1, 1994
Creator: King, A.G.
Partner: UNT Libraries Government Documents Department

Interpretation of subcriticality measurements with strong spatial effects

Description: A methodology has been developed to account for spatial effects in subcriticality measurements. Using experimental data, this new analysis methodology allows estimation of model contamination without previous knowledge about the system, neither in the form of neutronic or geometric factor calculations. 5 refs., 1 fig.
Date: January 1, 1987
Creator: March-Leuba, C.; March-Leuba, J. & Difilippo, F.C.
Partner: UNT Libraries Government Documents Department

Status of /sup 241/Am recovery and purification at Los Alamos Scientific Laboratory

Description: Americium recovery was initiated at Los Alamos Scientific Laboratory (LASL) in the late 1940's. The early procedures separated gram quantities of americium from large amounts of impurities including plutonium and the rare earths. Ion exchange procedures were developed for further purification. Until recently, no routine processing of americium has been done at LASL for several years. The increasing demand for americium in oil-well logging instruments and other uses led LASL to develop and install a process to recover larger quantities of americium. The LASL process was developed around the chemistry of americium that had been elucidated both at LASL and at other facilities. Presently, the americium feed is obtained as a by-product from a plutonium purification process at the new plutonium facility at LASL. This feed filtrate from a peroxide precipitation process is precipitated as a slurry of hydroxides, filtered, dissolved in nitric acid, and passed through an anion exchange column to remove any residual plutonium. The americium, contained in the effluent, is precipitated as the oxalate and calcined to the oxide. Americium is also available in other highly salted acidic process streams. These should lend themselves to solvent extraction. Developmental work has been promising, and a dibutyl butyl phosphate-kerosene extraction process is being brought on-line.
Date: January 1, 1980
Creator: Ramsey, H.D.; Clifton, D.G.; Hayter, S.W.; Penneman, R.A. & Christensen, E.L.
Partner: UNT Libraries Government Documents Department

Laboratory-scale shielded cell for /sup 252/Cf

Description: A shielded-cell facility for storing and handling remotely up to 2 milligram quantities of unencapsulated /sup 252/Cf has been built in a radiochemistry laboratory at the Test Reactor Area of the Idaho National Engineering Laboratory. Unique features of this facility are its compact bulk radiation shield of borated gypsum and transfer lines which permit the transport of fission product activity from /sup 252/Cf fission sources within the cell to a mass separator and to a fast radiochemistry system in nearby rooms.
Date: January 1, 1979
Creator: Anderl, R.A. & Cargo, C.H.
Partner: UNT Libraries Government Documents Department

Search for an elusive 4. 4-MeV. cap alpha. emitter in uranium minerals

Description: A search for an unidentified 4.4-MeV ..cap alpha..-emitter in Belgian Congo pitchblende and uranium raffinates is described, and a history of observations of 4.4-MeV activity over the last 55 years in radiogenic haloes, zinc ores, monazite, thorite, huttonite, ultrabasic and other abyssal rocks, osmiridium, uranium ores, and raffinates of uranium is given. No evidence of excess 4.4-MeV activity was shown in any of the chemically separated fractions investigated. Upper limits for 4.4-MeV ..cap alpha.. activity in each of four studied samples are given.
Date: December 1, 1979
Creator: Dougan, R.J.; Illige, J.D. & Hulet, E.K.
Partner: UNT Libraries Government Documents Department

DOT 7A FRP box fire test at the INEL

Description: Two fire tests were conducted at the INEL in December 1978, using both DOT 7A FRP boxes and DOT 17C steel drums. The containers tested were stacked in a configuration simulating the present storage array used at the RWMC. The fire tests revealed that when the DOT 7A FRP boxes were exposed to a small ignition source they would (a) in the WIPP environment, propogate fire resulting in the penetration of the boxes and probable spread of contamination unless fire suppression measures are taken, and (b) in the RWMC environment, probably not propogate the fire through the stack (the fire self extinguished during this test) although the possibility of the box breaching still exists, unless fire suppression measures are taken. The fire tests also revealed that the DOT 17C steel drums slowed the fire spread to the boxes, but that the rigid PVC (polyvinyl chloride) liner contained in the drum is highly combustible and presents an additional hazard. Under these test conditions, it was shown that a box could withstand the fire for at least 40 minutes without penetration, which would allow ample fire fighting response time if the blaze is detected early.
Date: June 1, 1979
Creator: Brown, R.M.
Partner: UNT Libraries Government Documents Department

Update summary of the 1991 discharge of enriched uranium to the sanitary sewer (DEUSS) report

Description: Since the 1991 Y-12 Plant report, a flow study of the Y-12 Plant sanitary sewer collection system has been completed by the Y-12 Plant staff (Hanzelka and Maguire, 1993). Additional data has been obtained by the Y-12 Plant and the City of Oak Ridge (COR, 1994). COR developed limits on radionuclide concentrations in sludges used for land application (Stetar, 1993). Martin Marietta Energy Systems has provided recommendations to the Department of Energy (DOE) regarding the impacts of sludge land farming operations on the ORR (Frye, 1992). The DOE Office of Nuclear Safety (USDOE, 1993) completed an audit of activities related to radiological contamination of the COR sewer system due to DOE operations. In addition COR is currently developing limits on radionuclide releases for all industrial customers to be applied through the permitting process. In 1994, a new sanitary sewer monitoring station was installed and began operation at the Y-12 Plant to determine releases specifically from the Y-12 Plant. Previously, estimates were based on mass balance calculations using data from the City Monitoring Station which monitors Union Valley and Y-12 Plant releases. The purpose of this report is to update the 1991 Y-12 Plant study taking into account current data and information.
Date: April 1, 1995
Partner: UNT Libraries Government Documents Department

Equipment and techniques for remote fabrication and calibration of physically small, high intensity /sup 252/Cf neutron sources

Description: Special equipment and techniques were required to fabricate /sup 252/Cf neutron source capsules, in which milligram quantities of /sup 252/Cf were concentrated in each capsule to approximate an idealized ''point source'' as closely as possible. Through this cooperative effort with the National Bureau of Standards all /sup 252/Cf neutron against the national reference radium-beryllium source.
Date: January 1, 1976
Creator: Williams, L. C.; Bigelow, J. E. & Knauer, J. B. Jr.
Partner: UNT Libraries Government Documents Department

RADEX: an active monitor for continuous measurement of /sup 222/Rn flux in soil

Description: A radon exhalation monitor, RADEX, was developed at the Environmental Measurements Laboratory. RADEX is an active radon monitor that continuously samples radon gas emanating from the soil. A hemispherical accumulator is placed on the soil and radon gas is drawn into the RADEX counter at a low, controlled flow rate. As /sup 222/Rn decays, the resulting radon daughters are focused by an electrostatic field, deposited directly onto a semiconductor detector, and counted. RADEX's ability to detect rapid changes in radon exhalation is made possible by analyzing RaA alphas with fast decay times. The pulses produced by the radon daughters are integrated hourly and are recorded. This system can operate unattended for 1 week, at which time a desiccant column must be changed. Thus, RADEX allows one to observe and to record continuously the radon flux from the soil. 8 references, 10 figures, 1 table.
Date: May 1, 1984
Creator: Watnick, S.; Latner, N. & Graveson, R.T.
Partner: UNT Libraries Government Documents Department

Electrical properties of air in the Carlsbad Caverns

Description: Radon 222 and its daughter product concentrations in the Carlsbad Caverns are higher than in outdoor air by a factor of several hundred. The effects of the radiation from these substances on the electrical properties of air in the cave have been studied. The rate of ion-pair production, the ion density, and the electrical conductivity are much higher in the Cave than in outdoor air. The mobility of the ions is less than outdoors due to the high humidity and low condensation nuclei concentration. A small net space charge produces a barely detectable electric field of the order of one percent of the earth's fair weather field.
Date: January 1, 1980
Creator: Wilkening, M. & Romero, V.
Partner: UNT Libraries Government Documents Department

Artificial heart development program. Volume II. System support. Phase III summary report, July 1, 1973--September 30, 1977

Description: Volume 2 covers major activities of the Artificial Heart Development program that supported the design, fabrication, and test of the system demonstration units. Section A.1.0 provides a listing beyond that of the body of the report on the components needed for an implantation. It also presents glove box sterilization calibration results and results of an extensive mock circulation calibration. Section A.2.0 provides detailed procedures for assembly, preparing for use, and the use of the system and major components. Section A.3.0 covers the component research and development activities undertaken to improve components of the existing system units and to prepare for a future prototype system. Section A.4.0 provides a listing of the top assembly drawings of the major systems variations fabricated and tested.
Date: January 1, 1977
Partner: UNT Libraries Government Documents Department

Performance testing of radiobioassay laboratories: In vitro measurements, fecal study report

Description: This study evaluated nine radiobioassay laboratories; performances in analyzing fecal samples to determine the samples' levels of radioactivity. A total of 135 artificial fecal samples were sent to nine laboratories. Each laboratory received five samples spiked with 9. 58 pCi of /sup 239/Pu, five samples spiked with 1.13 pCi /sup 239/Pu, and five unspiked blank samples. Four of the laboratories returned data for all samples; four reported they were unable to complete the analyses; one analyzed six samples (three blanks and three of the lower activity samples). Results reported by the laboratories were analyzed by statistical methods specified in the draft standard for relative bias, relative precision, and minimum detectable activity (MDA). The calculated relative biases of all laboratories were well within the criteria of the standard (/minus/0.25 to +0.5). Biases for three laboratories were about 5% and the two others were within +-20%. Relative precision statistics for all participating laboratories were lower than the acceptance criteria of the standard (40%). Relative precision was less than 15% for one laboratory; for two others, it was less than 10%; and for the remaining two, it was less than 5% of the acceptance criteria. For the MDA criterion, four of the five laboratories passed. For all four of the passing laboratories, the entire 90% confidence interval was less than the specified acceptable minimum detectable amount (acceptable MDA) of 1 pCi. for the fifth laboratory, the MDA was 80% above the acceptable MDA specified in the draft standard. 16 refs., 3 figs., 3 tabs.
Date: September 1, 1988
Creator: MacLellan, J.A.
Partner: UNT Libraries Government Documents Department

Plutonium-238 in sediment cores from the Mound Laboratory area

Description: Plutonium-238 concentrations in 8 sediment cores from water bodies near Mound Laboratory are reported. All have been measurably contaminated and for the most part show concentrations with depth in the sediment suggesting that chemical and/or biological processes may be quite active, and that run-off from nearby contaminated soil is probably continuing. The integrated Pu-238 deposits indicate that these samples essentially represent the complete sediment column.
Date: January 1, 1976
Creator: Volchok, H.
Partner: UNT Libraries Government Documents Department

Generation and mobility of radon in soil

Description: This study has confirmed large seasonal and daily variations of Rn in soil gas, developed models for the effects of temperature and moisture on air-water Rn partition, inhibited Rn diffusion from wet soil into sparse large air-filled pores and effects of diffusion into bedrock, demonstrated that organic matter is a major host for 226Ra in soils and that organic-bound Ra largely determines the proportion of 222Rn emanated to pore space, shown that in contrast 220Rn is emanated mainly from 224Ra in Fe-oxides, detected significant disequilibrium between 226Ra and 238U in organic matter and in some recent glacial soils, demonstrated by computer models that air convection driven by temperature differences is expected in moderately permeable soils on hillsides.
Date: January 1, 1993
Creator: Rose, A.W.; Jester, W.A. & Ciolkosz, E.J.
Partner: UNT Libraries Government Documents Department