Science.gov

Sample records for 239pu semi-experimental determination

  1. A Method for Continuous (239)Pu Determinations in Arctic and Antarctic Ice Cores.

    PubMed

    Arienzo, M M; McConnell, J R; Chellman, N; Criscitiello, A S; Curran, M; Fritzsche, D; Kipfstuhl, S; Mulvaney, R; Nolan, M; Opel, T; Sigl, M; Steffensen, J P

    2016-07-01

    Atmospheric nuclear weapons testing (NWT) resulted in the injection of plutonium (Pu) into the atmosphere and subsequent global deposition. We present a new method for continuous semiquantitative measurement of (239)Pu in ice cores, which was used to develop annual records of fallout from NWT in ten ice cores from Greenland and Antarctica. The (239)Pu was measured directly using an inductively coupled plasma-sector field mass spectrometer, thereby reducing analysis time and increasing depth-resolution with respect to previous methods. To validate this method, we compared our one year averaged results to published (239)Pu records and other records of NWT. The (239)Pu profiles from the Arctic ice cores reflected global trends in NWT and were in agreement with discrete Pu profiles from lower latitude ice cores. The (239)Pu measurements in the Antarctic ice cores tracked low latitude NWT, consistent with previously published discrete records from Antarctica. Advantages of the continuous (239)Pu measurement method are (1) reduced sample preparation and analysis time; (2) no requirement for additional ice samples for NWT fallout determinations; (3) measurements are exactly coregistered with all other chemical, elemental, isotopic, and gas measurements from the continuous analytical system; and (4) the long half-life means the (239)Pu record is stable through time. PMID:27244483

  2. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements.

    PubMed

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5 × 10(5) for 20 g soil compared to the level reported in the literature, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. PMID:24401459

  3. Determination of 239Pu and 240Pu isotope ratio for a nuclear bomb particle using X-ray spectrometry in conjunction with γ-ray spectrometry and non-destructive α-particle spectrometry

    NASA Astrophysics Data System (ADS)

    Pöllänen, R.; Ruotsalainen, K.; Toivonen, H.

    2009-11-01

    A nuclear bomb particle from Thule containing Pu and U was analyzed using X-ray spectrometry in combination with γ-ray spectrometry and non-destructive α-spectrometry. The main objective was to investigate the possibility to determine the 239Pu and 240Pu isotope ratios. Previously, X-ray spectrometry together with the above-mentioned methods has been successfully applied for radiochemically processed samples, but not for individual particles. In the present paper we demonstrate the power of non-destructive analysis. The 239Pu/( 239Pu+ 240Pu) atom ratio for the Thule particle was determined, using two different approaches, to be 0.93±0.07 and 0.91±0.05. These results are consistent with weapons-grade material and the results obtained by other investigators.

  4. Determination of 240Pu/239Pu isotopic ratios in human tissues collected from areas around the Semipalatinsk Nuclear Test Site by sector-field high resolution ICP-MS.

    PubMed

    Yamamoto, M; Oikawa, S; Sakaguchi, A; Tomita, J; Hoshi, M; Apsalikov, K N

    2008-09-01

    Information on the 240Pu/239Pu isotope ratios in human tissues for people living around the Semipalatinsk Nuclear Test Site (SNTS) was deduced from 9 sets of soft tissues and bones, and 23 other bone samples obtained by autopsy. Plutonium was radiochemically separated and purified, and plutonium isotopes (239Pu and 240Pu) were determined by sector-field high resolution inductively coupled plasma-mass spectrometry. For most of the tissue samples from the former nine subjects, low 240Pu/239Pu isotope ratios were determined: bone, 0.125 +/- 0.018 (0.113-0.145, n = 4); lungs, 0.063 +/- 0.010 (0.051-0.078, n = 5); and liver, 0.148 +/- 0.026 (0.104-0.189, n = 9). Only 239Pu was detected in the kidney samples; the amount of 240Pu was too small to be measured, probably due to the small size of samples analyzed. The mean 240Pu/239Pu isotope ratio for bone samples from the latter 23 subjects was 0.152 +/- 0.034, ranging from 0.088 to 0.207. A significant difference (a two-tailed Student's t test; 95% significant level, alpha = 0.05) between mean 240Pu/239Pu isotope ratios for the tissue samples and for the global fallout value (0.178 +/- 0.014) indicated that weapons-grade plutonium from the atomic bombs has been incorporated into the human tissues, especially lungs, in the residents living around the SNTS. The present 239,240Pu concentrations in bone, lung, and liver samples were, however, not much different from ranges found for human tissues from other countries that were due solely to global fallout during the 1970's-1980's. PMID:18695410

  5. Determination of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios in Brown Algae (Fucus distichus) Collected from Amchitka Island, Alaska.

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-05-02

    Plutonium-239 ({sup 239}Pu) and plutonium-240 ({sup 240}Pu) activity concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for Brown Algae (Fucus distichus) collected from the littoral zone of Amchitka Island (Alaska) and at a control site on the Alaskan peninsula. Plutonium isotope measurements were performed in replicate using Accelerator Mass Spectrometry (AMS). The average {sup 240}Pu/{sup 239}Pu atom ratio observed in dried Fucus d. collected from Amchitka Island was 0.227 {+-} 0.007 (n=5) and compares with the expected {sup 240}Pu/{sup 239}Pu atom ratio in integrated worldwide fallout deposition in the Northern Hemisphere of 0.1805 {+-} 0.0057 (Cooper et al., 2000). In general, the characteristically high {sup 240}Pu/{sup 239}Pu content of Fucus d. analyzed in this study appear to indicate the presence of a discernible basin-wide secondary source of plutonium entering the marine environment. Of interest to the study of plutonium source terms within the Pacific basin are reports of elevated {sup 240}Pu/{sup 239}Pu atom ratios in fallout debris from high-yield atmospheric nuclear tests conducted in the Marshall Islands during the 1950s (Diamond et al., 1960), the wide range of {sup 240}Pu/{sup 239}Pu atom ratio values (0.19 to 0.34) observed in sea water, sediments, coral and other environmental media from the North Pacific Ocean (Hirose et al., 1992; Buesseler, 1997) and updated estimates of the relative contributions of close-in and intermediate fallout deposition on oceanic inventories of radionuclidies, especially in the Northern Pacific Ocean (Hamilton, 2004).

  6. Ultra-trace determination of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell-ICP-MS/MS: Establishing a baseline for global fallout in Qatar soil and sediments.

    PubMed

    Amr, Mohamed A; Helal, Abdul-Fattah I; Al-Kinani, Athab T; Balakrishnan, Perumal

    2016-03-01

    The development of practical, fast, and reliable methods for the ultra-trace determination of anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu by triple quadruple collision/reaction cell inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS) were investigated in term of its accuracy and precision for producing reliable results. The radionuclides were extracted from 1 kg of the environmental soil samples by concentrated nitric and hydrochloric acids. The leachate solutions were measured directly by triple quadrupole CRC-ICP-MS/MS. For quality assurance, a chemical separation of the concerned radionuclides was conducted and then measured by single quadrupole-ICP-MS. The developed methods were next applied to measure the anthropogenic radionuclides (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu in soil samples collected throughout the State of Qatar. The average concentrations of (90)Sr, (137)Cs, (238)Pu, (239)Pu, and (240)Pu were 0.606 fg/g (3.364 Bq/kg), 0.619 fg/g (2.038 Bq/kg), 0.034 fg/g (0.0195 Bq/kg), 65.59 fg/g (0.150 Bq/kg), and 12.06 fg/g (0.103 Bq/kg), respectively. PMID:26736181

  7. Determination of fission neutron transmission through waste matrix material using neutron signal correlation from active assay of {sup 239}Pu

    SciTech Connect

    Hollas, C.L.; Arnone, G.; Brunson, G.; Coop, K.

    1996-09-01

    The accuracy of TRU (transuranic) waste assay using the differential die-away technique depends upon significant corrections to compensate for the effects of the matrix material in which the TRU waste is located. The authors have used a new instrument, the Combined Thermal/Epithermal Neutron (CTEN) instrument for the assay of TRU waste, to develop methods to improve the accuracy of these corrections. Neutrons from a pulsed 14-MeV neutron generator are moderated in the walls of the CTEN cavity and induce fission in the TRU material. The prompt neutrons from these fission events are detected in cadmium-wrapped {sup 3}He neutron detectors. They report new methods of data acquisition and analysis to extract correlation in the neutron signals resulting form fission during active interrogation. They use the correlation information in conjunction with the total number of neutrons to determine the fraction of fission neutrons transmitted through the matrix material into the {sup 3}He detectors. This determination allows them to cleanly separate the matrix effects into two processes: matrix modification upon the neutron interrogating flux and matrix modification upon the fraction of fission neutrons transmitted to the neutron detectors. This transmission information is also directly applied in a neutron multiplicity analysis in the passive assay of {sup 240}Pu.

  8. Determination of {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils by ICP-MS using flow-injection preconcentration

    SciTech Connect

    Hollenbach, M.; Grohs, J.; Mamich, S.; Kroft, M.

    1995-12-31

    The US Department of Energy needs improved analytical methods for alpha-emitting radionuclides to support environmental restoration and waste management projects. Inductively coupled plasma-mass spectrometry (ICP-MS) has been used successfully to measure radionuclides with relatively long half-lives; however, ICP-MS used with conventional sample introduction techniques lacks the sensitivity or selectivity to measure shorter-lived radionuclides at levels important for environmental monitoring. New methods were developed for measuring {sup 230}Th, {sup 234}U, {sup 239}Pu, and {sup 240}Pu in soils. Samples are dried, ground, and dissolved by fusion. A flow injection (FI) analysis system is used to separate and concentrate the analytes by solid-phase extraction. The FI eluent is pumped directly into the nebulizer of the ICP-MS. The use of FI resulted in greater sensitivity and freedom from interferences when compared with direct aspiration. Detection limits are improved by approximately a factor of 20. The detection limits are approximately 3 Bq/kg (4 ng/kg) for {sup 230}Th, 0.6 Bq/kg (3 ng/kg) for {sup 234}U, 0.4 Bq/kg (0.2 ng/kg) for {sup 239}Pu, and 2 Bq/kg (0.3 ng/kg) for {sup 240}Pu. The FI-ICP-MS methods are faster, less labor intensive, and generate less laboratory waste than traditional radiochemical methods. The FI-ICP-MS gives individual results for {sup 239}Pu and {sup 240}Pu which cannot be resolved by the usual radiochemical method. The accuracy of the methods was verified by analyzing reference soils.

  9. Simultaneous determination of radiocesium ((135)Cs, (137)Cs) and plutonium ((239)Pu, (240)Pu) isotopes in river suspended particles by ICP-MS/MS and SF-ICP-MS.

    PubMed

    Cao, Liguo; Zheng, Jian; Tsukada, Hirofumi; Pan, Shaoming; Wang, Zhongtang; Tagami, Keiko; Uchida, Shigeo

    2016-10-01

    Due to radioisotope releases in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, long-term monitoring of radiocesium ((135)Cs and (137)Cs) and Pu isotopes ((239)Pu and (240)Pu) in river suspended particles is necessary to study the transport and fate of these long-lived radioisotopes in the land-ocean system. However, it is expensive and technically difficult to collect samples of suspended particles from river and ocean. Thus, simultaneous determination of multi-radionuclides remains as a challenging topic. In this study, for the first time, we report an analytical method for simultaneous determination of radiocesium and Pu isotopes in suspended particles with small sample size (1-2g). Radiocesium and Pu were sequentially pre-concentrated using ammonium molybdophosphate and ferric hydroxide co-precipitation, respectively. After the two-stage ion-exchange chromatography separation from the matrix elements, radiocesium and Pu isotopes were finally determined by ICP-MS/MS and SF-ICP-MS, respectively. The interfering elements of U ((238)U(1)H(+) and (238)U(2)H(+) for (239)Pu and (240)Pu, respectively) and Ba ((135)Ba(+) and (137)Ba(+) for (135)Cs and (137)Cs, respectively) were sufficiently removed with the decontamination factors of 1-8×10(6) and 1×10(4), respectively, with the developed method. Soil reference materials were utilized for method validation, and the obtained (135)Cs/(137)Cs and (240)Pu/(239)Pu atom ratios, and (239+240)Pu activities showed a good agreement with the certified/information values. In addition, the developed method was applied to analyze radiocesium and Pu in the suspended particles of land water samples collected from Fukushima Prefecture after the FDNPP accident. The (135)Cs/(137)Cs atom ratios (0.329-0.391) and (137)Cs activities (23.4-152Bq/g) suggested radiocesium contamination of the suspended particles mainly originated from the accident-released radioactive contaminates, while similar Pu contamination of suspended

  10. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

  11. Chronic cigarette smoke exposure increases the pulmonary retention and radiation dose of {sup 239}Pu inhaled as {sup 239}PuO{sub 2} by F344 rats

    SciTech Connect

    Finch, G.L.; Lundgren, D.L.; Barr, E.B.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Nikula, K.J.; Mauderly, J.L.

    1998-12-01

    As a portion of a study to examine how chronic cigarette smoke exposure might alter the risk of lung tumors from inhaled {sup 239}PuO{sub 2} in rats, the effects of smoke exposure on alpha-particle lung dosimetry over the life-span of exposed rats were determined. Male and female rats were exposed to inhaled {sup 239}PuO{sub 2} alone or in combination with cigarette smoke. Animals exposed to filtered air along served as controls for the smoke exposure. Whole-body exposure to mainstream smoke diluted to concentrations of either 100 or 250 mg total particulate matter m{sup {minus}3} began at 6 wk of age and continued for 6 h d{sup {minus}1}, 5 d wk{sup {minus}1}, for 30 mo. A single, pernasal, acute exposure to {sup 239}PuO{sub 2} was given to all rats at 12 wk of age. Exposure to cigarette smoke caused decreased body weight gains in a concentration dependent manner. Lung-to-body weight ratios were increased in smoke-exposed rats. Rats exposed to cigarette smoke before the {sup 239}PuO{sub 2} exposure deposited less {sup 239}Pu in the lung than did controls. Except for male rats exposed to LCS, exposure to smoke retarded the clearance of {sup 239}Pu from the lung compared to control rats through study termination at 870 d after {sup 239}PuO{sub 2} exposure. Radiation doses to lungs were calculated by sex and by exposure group for rats on study for at least 360 d using modeled body weight changes, lung-to-body weight ratios, and standard dosimetric calculations. For both sexes, estimated lifetime radiation doses from the time of {sup 239}PuO{sub 2} exposure to death were 3.8 Gy, 4.4 Gy, or 6.7 Gy for the control, LCS, or HCS exposure groups, respectively. Assuming an approximately linear dose-response relationship between radiation dose and lung neoplasm incidence, approximate increases of 20% or 80% in tumor incidence over controls would be expected in rats exposed to {sup 239}PuO{sub 2} and LCS or {sup 239}PuO{sub 2} and HCS, respectively.

  12. Room-temperature electron spectroscopy of 239Pu and 240Pu

    NASA Astrophysics Data System (ADS)

    Ahmad, I.; Kondev, F. G.; Greene, J. P.; Zhu, S.

    2015-06-01

    Passivated, implanted, planar silicon (PIPS) detectors have been used for the measurement of electron spectra. The commercially available PIPS detectors, available in thicknesses of 100 μm, 300 μm, and 500 μm, have an energy resolution (FWHM) of ~ 2.2 keV, which is essentially the same as that of PIN diodes. Alpha and electron spectra of mass-separated 239Pu and 240Pu sources have been measured with a 300-μm thick PIPS detector and the electron to alpha ratios for the conversion lines of the 51.62- and 45.24-keV transitions have been determined. A procedure has been developed to determine the amount of 239Pu and 240Pu in a mixed source. The α-particle emission rate of the mixed source is measured, which is the sum of individual rates. From the electron spectrum of the mixed source, measured with the same setup as the alpha spectrum, the rates of 239Pu electron lines are determined. Using the electron rate of the 239Pu line and the electron to alpha ratio measured for the pure source, the α-particle emission rate of 239Pu is determined. The difference from the total α-particle emission rate gives the α-particle emission rate of 240Pu. In addition, electron intensities and conversion coefficients of the 239Pu and 240Pu transitions have been measured.

  13. Microdistribution and retention of injected /sup 239/Pu on trabecular bone surfaces of the beagle: implications for the induction of osteosarcoma

    SciTech Connect

    Wronski, T.J.; Smith, J.M.; Jee, W.S.S.

    1980-07-01

    A study was initiated to investigate the relationship between skeletal remodeling and the microdistribution and retention of /sup 239/Pu on trabecular bone surfaces of the beagle, and the contribution of these parameters to the nonuniform skeletal distribution of /sup 239/Pu-induced osteosarcomas. Young adult beagles were administered single iv injections of approx. 0.016 ..mu..Ci/kg monomeric /sup 239/Pu citrate and sacrificed at various times to 1 year after injection. The /sup 239/Pu concentration on trabecular bone surfaces was determined by counting fission fragment tracks in neutron-induced autoradiographs produced from thick (approx. 400 ..mu..m) bone sections. The rate of trabecular bone formation was calculated from an ultraviolet microscopic analysis of fluorescent tetracycline labels. The lumbar vertebra, pelvis, and proximal humerus, each of which exhibits a high incidence of /sup 239/Pu-induced osteosarcoma, were found to have a high intial concentration of /sup 239/Pu on their trabecular surfaces (approx. 7-8 pCi/cm/sup 2/) and a relatively high rate of trabecular bone formation. The /sup 239/Pu concentration at these sites decreased to approx. 2-3 pCi/cm/sup 2/ at the end of the first year. On the other hand, the proximal ulna and distal humerus, skeletal sites with a low tumor incidence, had a low intial concentration of /sup 239/Pu on their trabecular surfaces(approx. 1-2 pCi/cm/sup 2/) and a significantly lower rate of trabecular bone formation (P < 0.01). The /sup 239/Pu concentration at these sites remained nearly constant throughout the experimental period. These data suggest that the degree of the initial deposition of /sup 239/Pu on trabecular bone surfaces and the rate of trabecular bone turnover may play a role in the genesis of /sup 239/Pu-induced osteosarcomas.

  14. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    NASA Astrophysics Data System (ADS)

    Leal, L. C.; Noguere, G.; de Saint Jean, C.; Kahler, A. C.

    2014-04-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deficiency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplicity (νbar) and the prompt neutron fission spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation effort.

  15. [ECG indices in dogs after inhalation of 239Pu].

    PubMed

    Karpova, V N

    1985-11-01

    Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs. PMID:4068946

  16. Exposure of F344 rats to aerosols of {sup 239}PuO{sub 2} and chronically inhaled cigarette smoke

    SciTech Connect

    Finch, G.L.; Nikula, K.J.; Barr, E.B.; Bechtold, W.E.; Chen, B.T.; Griffith, W.C.; Hobbs, C.H.; Hoover, M.D.; Mauderly, J.L.

    1994-11-01

    Nuclear workers may be accidently exposed to radioactive materials such as {sup 239}PuO{sub 2} by inhalation, and thus have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radionuclides and other carcinogens may increase the risk of cancer induction. An important and common lung carcinogen is cigarette smoke. This study is being conducted to better determine the combined effects of inhaled {sup 239}PuO{sub 2} and cigarette smoke on the induction of lung cancer in rats.

  17. European roe deer antlers as an environmental archive for fallout (236)U and (239)Pu.

    PubMed

    Froehlich, M B; Steier, P; Wallner, G; Fifield, L K

    2016-01-01

    Anthropogenic (236)U and (239)Pu were measured in European roe deer antlers hunted between 1955 and 1977 which covers and extends beyond the period of intensive nuclear weapons testing (1954-1962). The antlers were hunting trophies, and hence the hunting area, the year of shooting and the approximate age of each animal is given. Uranium and plutonium are known to deposit in skeletal tissue. Since antler histology is similar to bone, both elements were expected in antlers. Furthermore, roe deer shed their antlers annually, and hence antlers may provide a time-resolved environmental archive for fallout radionuclides. The radiochemical procedure is based on a Pu separation step by anion exchange (Dowex 1 × 8) and a subsequent U purification by extraction chromatography using UTEVA(®). The samples were measured by Accelerator Mass Spectrometry at the VERA facility (University of Vienna). In addition to the (236)U and (239)Pu concentrations, the (240)Pu/(239)Pu isotopic ratios were determined with a mean value of 0.172 ± 0.023 which is in agreement with the ratio of global fallout (∼0.18). Rather high (236)U/(238)U ratios of the order of 10(-6) were observed. These measured ratios, where the (236)U arises only from global fallout, have implications for the use of the (236)U/(238)U ratio as a fingerprint for nuclear accidents or releases from nuclear facilities. Our investigations have shown the potential to use antlers as a temporally resolved archive for the uptake of actinides from the environment. PMID:26119579

  18. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    SciTech Connect

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2008-08-01

    In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

  19. Normalization of the [sup 239]Pu fission cross section

    SciTech Connect

    Wagemans, C.; Van Uffelen, P.; Deruytter, A.; Barthelemy, R.; Van Gils, J. . Joint Research Centre)

    1993-10-01

    Measurements have been performed at the Geel Linear Accelerator from 0.01 eV up to 1,000 eV in order to investigate the normalization of [sup 239]Pu fission cross-section measurements. Two different experiments were performed using surface barrier detectors and a double ionization chamber, respectively. In both cases, the [sup 10]B(n, [alpha]) reaction was used as a flux monitor. The results indicate that the Weston and Todd data should be renormalized by [approximately]3%, resulting in a satisfactory agreement with ENDF/B-VI.

  20. Surrogate Reaction Measurement of Angular Dependent 239Pu (n , f) Probabilities

    NASA Astrophysics Data System (ADS)

    Koglin, Johnathon; Burke, Jason; Casperson, Robert; Jovanovic, Igor

    2015-10-01

    The surrogate method has previously been used to measure (n , f) cross sections of difficult to produce actinide isotopes. These measurements have inaccuracies at excitation energies below 1.5 MeV where the distribution of angular momentum states populated in the compound nucleus created by neutron absorption significantly differs from that arising from direct reactions. A method to measure the fission probability of individual angular momentum states arising from 239Pu (d , pf) and 239Pu (α ,α' f) reactions has been developed. This experimental apparatus consists of charged particle detectors with 40 keV FWHM resolution at 13 angles up and downstream of the particle beam. A segmented array of photovoltaic (solar) cells is used to measure the angular distribution of fission fragments. This distribution uniquely identifies the populated angular momentum states. These are fit to expected distributions to determine the contribution of each state. The charged particle and fission rates matrix obtained from this analysis determines fission probabilities of specific angular momentum states in the transition nucleus. Development of this scheme and first results will be discussed.

  1. Gamma-ray Output Spectra from 239 Pu Fission

    DOE PAGESBeta

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-raymore » multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

  2. Gamma-ray Output Spectra from 239Pu Fission

    NASA Astrophysics Data System (ADS)

    Ullmann, John

    2015-05-01

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.

  3. Random Probability Analysis of 48Ca +239Pu Experimental Data

    NASA Astrophysics Data System (ADS)

    Strauss, S. Y.; Henderson, R. A.; Stoyer, M. A.; Abdullin, A. F. Sh.; Brewer, N. T.; Dmitriev, S. N.; Grzywacz, R. K.; Hamilton, J. H.; Itkis, M. G.; Miernik, K.; Oganessian, Yu. Ts.; Polyakov, A. N.; Roberto, J. B.; Rykaczewski, K. P.; Sabelnikov, A. V.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeyko, M. V.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu. S.; Utyonkov, V. K.; Voinov, A. A.; Vostokin, G. K.

    2014-09-01

    Element 114 (Fl), was discovered at the Flerov Laboratory of Nuclear Reactions (FLNR) using the 48Ca +244Pu reaction and the Dubna Gas-Filled Recoil Separator (DGFRS). The structural properties of the super heavy elements are still largely unknown. The extent of the region of enhanced stability near Z = 114 and N = 184 is not completely known. To examine these properties, a new experimental data set has been taken using the 48Ca +239Pu reaction at the DGFRS, in an effort to look for lighter isotopes of Fl. Progress on the production of lighter isotopes of Fl, cross-section measurements, and any nuclear decay properties will be discussed. Comparisons with reactions using heavier 242,244Pu targets and Monte Carlo random probability analysis will be highlighted. Element 114 (Fl), was discovered at the Flerov Laboratory of Nuclear Reactions (FLNR) using the 48Ca +244Pu reaction and the Dubna Gas-Filled Recoil Separator (DGFRS). The structural properties of the super heavy elements are still largely unknown. The extent of the region of enhanced stability near Z = 114 and N = 184 is not completely known. To examine these properties, a new experimental data set has been taken using the 48Ca +239Pu reaction at the DGFRS, in an effort to look for lighter isotopes of Fl. Progress on the production of lighter isotopes of Fl, cross-section measurements, and any nuclear decay properties will be discussed. Comparisons with reactions using heavier 242,244Pu targets and Monte Carlo random probability analysis will be highlighted. This work was performed under Contract DE-AC52-07NA27344 and Grant DE-NA0002135.

  4. Study of neutron-deficient isotopes of Fl in the 239Pu, 240Pu + 48Ca reactions

    NASA Astrophysics Data System (ADS)

    Voinov, A. A.; Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu Ts; Rykaczewski, K. P.; Abdullin, F. Sh; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu S.; Subbotin, V. G.; Sukhov, A. M.; Sabelnikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2016-07-01

    The results of the experiments aimed at the synthesis of Fl isotopes in the 239Pu + 48Ca and 240Pu + 48Ca reactions are presented. The experiment was performed using the Dubna gas-filled recoil separator at the U400 cyclotron. In the 239Pu+48Ca experiment one decay of spontaneously fissioning 284Fl was detected at 245-MeV beam energy. In the 240Pu+48Ca experiment three decay chains of 285Fl were detected at 245 MeV and four decays were assigned to 284Fl at the higher 48Ca beam energy of 250 MeV. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined more precisely. The cross section of the 239Pu(48Ca,3n)284Fl reaction was observed to be about 20 times lower than those predicted by theoretical models and 50 times less than the value measured in the 244Pu+48Ca reaction. The cross sections of the 240Pu(48Ca,4-3n)284,285Fl at both 48Ca energies are similar and exceed that observed in the reaction with lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate rapid decrease of stability of superheavy nuclei with departing from the neutron number N=184 predicted to be the next magic number.

  5. Correlation of /sup 239/Pu thermal and fast reactor fission yields with neutron energy

    SciTech Connect

    Maeck, W.J.

    1981-10-01

    The relative isotopic abundances and the fisson yields for over 40 stable and long-lived fission products from /sup 239/Pu fast fission were evaluated to determine if the data could be correlated with neutron energy. Only mass spectrometric data were used in this study. For some nuclides changes of only a few percent in the relative isotopic abundance or the fission yields over the energy range of thermal to 1 MeV are easily discernable and significant; for others the data are too sparse and scattered to obtain a good correlation. The neutron energy index usedin this study is the /sup 150/Nd//sup 143/Nd isotopic ratio. The results of this correlation study compared to the US Evaluated Nuclear Data File (ENDF) fast fission yield compilation. Several discrepancies are noted and suggestions for future work are presented.

  6. Prompt Fission Neutron Emission in Resonance Fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef; Varapai, Natallia; Zeinalov, Shakir; Oberstedt, Stephan; Serot, Olivier

    2005-05-01

    The prompt neutron emission probability from neutron-induced fission in the resonance region is being investigated at the time-of-flight facility GELINA of the IRMM. A double Frisch-gridded ionization chamber is used as a fission-fragment detector. For the data acquisition of both the fission-fragment signals as well as the neutron detector signals the fast digitization technique has been applied. For the neutron detection, large-volume liquid scintillation detectors from the DEMON collaboration are used. A specialized data analysis program taking advantage of the digital filtering technique has been developed to treat the acquired data. Neutron multiplicity investigations for actinides, especially in resonance neutron-induced fission, are rather scarce. They are, however, important for reactor control and safety issues as well as for understanding the basic physics of the fission process. Fission yield measurements on both 235U and 239Pu without prompt neutron emission coincidence have shown that fluctuation of the fission-fragment mass distribution exists from resonance to resonance, larger in the case of 235U. To possibly explain these observations, the question now is whether the prompt neutron multiplicity shows similar fluctuations with resonance energy.

  7. Osteosarcomas among beagles exposed to /sup 239/Pu

    SciTech Connect

    Whittemore, A.S.; McMillan, A.

    1982-04-01

    A Weibull distribution was fit to the osteosarcoma death times of beagles given single intravenous injections of /sup 239/Pu. For injected doses in the range 0-1..mu..Ci/kg the osteosarcoma incidence rate h(t) at t days after injection can be fit by a quadratic function of injected dose d: h(t) = 2.61 X 10/sup -18/ d/sup 2/t/sup 4.91/. The best-fitting linear function was rejected by the data (P < 0.001). A different formula for h(t), derived from a multistage theory for osteosarcoma induction, was also fit to these data. For this purpose microdosimetry calculations were used to estimate the dose to the cells at risk in the endosteal layer (endosteal dose). According to the best fit, h(t) is a quadratic function of endosteal dose at low doses. A linear dose-response relationship was again rejected. The absence of a linear component at low doses might be explained by the fact that 108 of the 185 animals injected at the lowest doses (<0.02 ..mu..Ci/kg) were still alive at the time these data were collected.

  8. A comparison of fallout (236)U and (239)Pu uptake by Australian vegetation.

    PubMed

    Froehlich, M B; Dietze, M M A; Tims, S G; Fifield, L K

    2016-01-01

    The isotopes (236)U and (239)Pu, both produced during nuclear weapons tests carried out in the 1950s and 1960s, are present in the environment and may be used as tracers for soil erosion studies. Although these radionuclides occur only at ultra-trace levels in nature, they can be readily measured by accelerator mass spectrometry with the 14UD heavy ion accelerator at the Australian National University. We have analysed a series of vegetation samples for their (236)U and (239)Pu concentration and compared the results with those found in the surrounding soil. (236)U could be measured in all collected samples whereas (239)Pu could not be detected in several vegetation samples due to its very low concentration, although it was readily detectable in the soil. We find that, relative to plutonium, (236)U is preferentially taken up by plants with enrichment factors ((236)U/(239)Pu)veg/((236)U/(239)Pu)soil that range between 7 and 52 in the present study. PMID:26141188

  9. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  10. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  11. A generalized method for characterization of 235U and 239Pu content using short-lived fission product gamma spectroscopy

    DOE PAGESBeta

    Knowles, Justin R.; Skutnik, Steven E.; Glasgow, David C.; Kapsimalis, Roger J.

    2016-06-23

    Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification,more » mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. Furthermore, it is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.« less

  12. Measurement of 239Pu in urine samples at ultra-trace levels using a 1 MV compact AMS system

    NASA Astrophysics Data System (ADS)

    Hernández-Mendoza, H.; Chamizo, E.; Yllera, A.; García-León, M.; Delgado, A.

    2010-04-01

    Routine bioassay monitoring of Pu intake in exposed workers of research and nuclear industry is usually performed by alpha spectrometry. This technique involves large sample volumes of urine and time-consuming preparative and counting protocols. Compact accelerator mass spectrometry (AMS) facilities make feasible the determination of ultra low-level Pu activity concentrations and Pu isotopic ratios in biological samples (blood, urine and feces), being a rapid and cost-effective measurement technique. The plutonium results in urine samples presented here have been obtained on the 1 MV compact AMS system sited at the Centro Nacional de Aceleradores (CNA), in Seville, Spain. In this work, a different methodological approach has been developed alternative to the "classical" preparation of urine samples for alpha spectrometry. The procedure avoids the Pu precipitation step, and involves acid sample evaporation and acid digestion in a microwave oven. Finally, purification of plutonium was achieved by using chromatography columns filled up with BioRad AG1X2 anion exchange resin (Bio-Rad Laboratories Inc.). The total time needed for analysis is about 10 h, unlike the "classical" methods based on alpha spectrometry which need about 1 week. At present, it has been demonstrated that this method allows quantifying 239Pu activity concentrations in urine of, at least, 30 μBq (13 fg 239Pu). We can conclude that the procedure would be suitable to perform in vitro routine bioassay measurements. Moreover, the innovative application of AMS opens new and interesting analytical alternatives in this field.

  13. Comparison of early mortality in baboons and dogs after inhalation of /sup 239/PuO/sub 2/

    SciTech Connect

    Bair, W.J.; Metivier, H.; Park, J.F.; Masse, R.; Stevens, D.L.; Lafuma, J.; Watson, C.R.; Nolibe, D.

    1980-06-01

    Results from experiments with baboons were compared with those from experiments with dogs to determine the relative sensitivity of the two species to early mortality from inhaled /sup 239/PuO/sub 2/. To ensure a valid comparison of data developed at two laboratories, methodology differences were minimized by establishing a common pool of raw data, using the same computer programs to analyze the data, and standardizing assumptions regarding the calculation of plutonium concentration in lungs. Several comparison methods were used involving variations in estimating different parameters used in these calculations. Although nearly all comparisons suggested baboons were slightly more sensitive, none of the methods for comparing the relationship between dose and survival time showed consistently significant differences between baboons and dogs. Although the baboons were physiologically and morphologically immature when exposed to plutonium, whereas the dogs were mature, we concluded that adult baboons and dogs are similarly sensitive to the early effects of inhaled /sup 239/PuO/sub 2/. Since only early mortality was considered in this comparison, the results do not apply to possible late effects caused by much lower levels of plutonium than were used in these experiments.

  14. Pulmonary retention and tissue distribution of {sup 239}Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.; Nikula, K.J.

    1994-11-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl{sub 4} and plutonium compounds. Potential for future exposure exists during {open_quotes}cleanup{close_quotes} operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl{sub 4} is 5 ppm; however, concentrations of CCl{sub 4} occurring in the nuclear weapons facilities over the past 40-50 y are unknown and may have exceeded this value. The pilot study described in this report is designed to determine whether subchronic inhalation of CCl{sub 4} by CDF{sup register}(F-344)/CrlBR rats and Syrian golden hamsters, at concentrations expected to produce some histologic changes in liver, alters the hepatic retention and toxic effects of inhaled {sup 239}Pu nitrate {sup 239}Pu(NO{sub 3}){sub 4}.

  15. A GENERALIZED METHOD FOR CHARACTERIZATION OF 235U AND 239PU CONTENT USING SHORT-LIVED FISSION PRODUCT GAMMA SPECTROSCOPY

    SciTech Connect

    Knowles, Justin R; Skutnik, Steven E; Glasgow, David C; Kapsimalis, Roger J

    2016-01-01

    Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification, mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. It is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.

  16. Photofission product yields of 238U and 239Pu with 22-MeV bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Wen, Xianfei; Yang, Haori

    2016-06-01

    In homeland security and nuclear safeguards applications, non-destructive techniques to identify and quantify special nuclear materials are in great demand. Although nuclear materials naturally emit characteristic radiation (e.g. neutrons, γ-rays), their intensity and energy are normally low. Furthermore, such radiation could be intentionally shielded with ease or buried in high-level background. Active interrogation techniques based on photofission have been identified as effective assay approaches to address this issue. In designing such assay systems, nuclear data, like photofission product yields, plays a crucial role. Although fission yields for neutron-induced reactions have been well studied and readily available in various nuclear databases, data on photofission product yields is rather scarce. This poses a great challenge to the application of photofission techniques. In this work, short-lived high-energy delayed γ-rays from photofission of 238U were measured in between linac pulses. In addition, a list-mode system was developed to measure relatively long-lived delayed γ-rays from photofission of 238U and 239Pu after the irradiation. Time and energy information of each γ-ray event were simultaneously recorded by this system. Cumulative photofission product yields were then determined using the measured delayed γ-ray spectra.

  17. Isotopic yield measurement in the heavy mass region for 239Pu thermal neutron induced fission

    NASA Astrophysics Data System (ADS)

    Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Köster, U.; Faust, H.; Letourneau, A.; Panebianco, S.

    2011-09-01

    Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the 239Pu(nth,f) reaction. In order to do this, a new experimental method based on γ-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

  18. Evaluation of the 239Pu(n,2n) Integrated Cross Section

    SciTech Connect

    McNabb, D P; Anderson, J D; Bauer, R W; Becker, J A; Dietrich, F; Navratil, P; Chadwick, M B; Young, P G

    2001-01-25

    Recently, new cross section measurements by the GEANIE collaboration have been published for {sup 239}Pu(n, 2n{gamma}) [Ber00] and {sup 235}U(n, 2n{gamma}) [You00] from threshold to 20 MeV. When combined with nuclear reaction calculations [Che00, Cha99, Cha01], these measurements provide the most accurate information available on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section for incident neutron energies, E{sub n} {approx}< 14 MeV. This new data has prompted a re-evaluation of the {sup 239}Pu(n, 2n) {sup 238}Pu reaction cross section considering all available experimental data. The data prior to the measurement of Bernstein et al. [Ber00] is illustrated in Figure 1a. These data sets were considered by previous evaluations [ENDL] of the {sup 239}Pu(n, 2n) cross section. The most precise experiment was an activation measurement done by Lougheed et al. [Lou00] for incident neutron energies, E{sub n}, between 13-15 MeV. In addition, there were two neutron-counting experiments, one by Mather et al. [Mat72] and one by Frehaut et al. [Fre85]. These two measurements cover a wide incident neutron range, with data points from threshold to E{sub n} {approx} 14 MeV. The available data sets are in poor agreement with each other and in some cases do not meet basic expectations. These experiments will be reviewed in detail. The new contributions to this evaluation are (1) the GEANIE data coupled with reaction modeling, illustrated in Figure 1b, and (2) the systematic use of other nuclear data in order to put constraints on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section. The approach of this evaluation has been to use consistency arguments supported by nuclear data to resolve the measurement differences, with the goal of providing: (1) A comprehensive picture of our knowledge on the {sup 239}Pu(n, 2n) cross section; and (2) A new evaluation including the best possible estimate of the cross section and a one-sigma estimate the uncertainties. This

  19. The Investigation of the Doppler-Effect of the α-Value of 235U and 239Pu for Different Temperatures

    NASA Astrophysics Data System (ADS)

    Grigoriev, Yu. V.; Kitaev, V. Ya.; Sinitsa, V. V.; Mezentseva, Zh. V.; Faikov-Stanczyk, H.; Janeva, N. B.

    2005-05-01

    The time-of-flight spectra for γ -ray multiplicities from 1 to 15 were measured on the 122-m flight path of the IBR-30 pulsed neutron booster using the 16-section liquid scintillation detector for thin metallic radiator-samples of 235U (0.25 mm) and 239Pu (0.3 mm) at the presence of 235U and 239Pu filter-samples with a thickness of 0.5 mm at two temperatures (100 K and 293 K). Multiplicity spectra, Doppler-coefficients of the capture, fission cross-sections, and alpha values (their ratio) were determined from the time-of-flight spectra for above-mentioned temperatures.

  20. Potential of Vetiveria zizanoides L. Nash for phytoremediation of plutonium ((239)Pu): Chelate assisted uptake and translocation.

    PubMed

    Singh, Shraddha; Fulzele, D P; Kaushik, C P

    2016-10-01

    Plants have demonstrated a great potential to remove toxic elements from soils and solutions and been successfully used for phytoremediation of important radionuclides. Uptake potential of vetiver plants (V. zizanoides) for the remediation of (239)Pu in hydroponic and soil conditions was studied in the present work. High efficiency of V. zizanoides for the removal of (239)Pu was recorded with 66.2% being removed from the hydroponic solution after 30 days. However, remediation of (239)Pu from soil was limited. Remediation of (239)Pu from soil was increased with the addition of chelating agents citric acid (CA) and diethylenetriaminepentaacetic acid (DTPA). Accumulation of (239)Pu was recorded higher in roots than shoots, however its translocation from roots to shoots increased in the presence of chelators in hydroponic as well as soil conditions. DTPA was found more effective than CA showing higher translocation index (TI). Increase in TI was observed 8 and 6 times in the solution and soil respectively when plants were exposed to (239)Pu-DTPA in comparison to only (239)Pu. The present study demonstrates that V. zizanoides plant is a potential plant for phytoremediation of (239)Pu. PMID:27318195

  1. Resource Note on Photofission of Nuclei for {sup 235}U and {sup 239}Pu Detection

    SciTech Connect

    Nieto, Michael Martin

    2004-11-15

    Open-source data exist, in widely scattered places, on photofission of the important nuclear isotopes {sup 235}U and {sup 239}Pu. These data are useful for studies aimed at detecting these materials at ports of entry. An introductory survey is given to access that data.

  2. /sup 237/Np and /sup 239/Pu solution behavior during hydrothermal testing of simulated nuclear waste glass with basalt and steel

    SciTech Connect

    Schramke, J.A.; Simonson, S.A.; Coles, D.G.

    1984-09-01

    A series of hydrothermal experiments were carried out on /sup 237/Np- and /sup 239/Pu-doped PNL 76-68 glass, synthetic basalt groundwater, basalt, and cast steel. Experiments of duration were conducted in Dickson-type rocking autoclaves at 200/sup 0/C and 30 MPa, with an initial fluid to solid weight ratio of 10:1. The tests carried out were: glass and groundwater; glass, basalt, and groundwater; glass, steel, and groundwater; and glass, steel, basalt, and groundwater. Unfiltered, 4000 A filtered, and 18 A filtered solutions were analyzed to determine the concentrations of radionuclides in solution and those associated with colloids. In all four experiments, /sup 237/Np and /sup 239/Pu were present in solution in quantities at or below the analytical detection limits. The only detectable differences in radionuclide concentrations between the four experiments were brought about by changes in the amounts of colloidally associated radionuclides. Besalt added to the glass and groundwater system increased the quantities of the colloidally associated /sup 237/Np and /sup 239/Pu by an order of magnitude. The addition of steel to the glass and groundwater system reduced the colloidally associated radionuclides to levels below detection limits. The effects of both steel and basalt on the glass and groundwater system seemed to cancel out, and the colloidally associated radionuclide concentrations were similar to the observed levels in the glass plus groundwater system. These variations in the quantities of the colloidally associated radionuclides did not appear to be correlated with other changes in the quantities or composition of the colloidal material in solution. Other than /sup 237/Np and /sup 239/Pu, silica was the only constituent of the colloids in these experiments. The amounts of colloidal silica did not vary significantly between the four experiments. 7 references, 7 figures.

  3. Measurement of 240Pu/239Pu isotopic ratios in soils from the Marshall Islands using ICP-MS.

    PubMed

    Muramatsu, Y; Hamilton, T; Uchida, S; Tagami, K; Yoshida, S; Robison, W

    2001-10-20

    Nuclear weapons tests conducted by the United States in the Marshall Islands produced significant quantities of regional or tropospheric fallout contamination. Here we report on some preliminary inductively coupled plasma-mass spectrometry (ICP-MS) measurements of plutonium isolated from seven composite soil samples collected from Bikini, Enewetak and Rongelap Atolls in the northern Marshall Islands. These data show that 240Pu/239Pu isotopic signatures in surface soils from the Marshall Island vary significantly and could potentially be used to help quantify the range and extent of fallout deposition (and associated impacts) from specific weapons tests. 137Cs and 60Co were also determined on the same set of soil samples for comparative purposes. PMID:11669263

  4. Neutron and gamma-ray spectra of 239PuBe and 241AmBe.

    PubMed

    Vega-Carrillo, Héctor René; Manzanares-Acuña, Eduardo; Becerra-Ferreiro, Ana María; Carrillo-Nuñez, Aureliano

    2002-08-01

    Neutron and gamma-ray spectra of 239PuBe and 241AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6LiI(Eu) scintillator. The 239PuBe neutron spectrum was measured in an open environment, while the 241AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the 241AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity. PMID:12150274

  5. Studies of Neutron-Induced Fission of 235U, 238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Duke, Dana; TKE Team

    2014-09-01

    A Frisch-gridded ionization chamber and the double energy (2E) analysis method were used to study mass yield distributions and average total kinetic energy (TKE) release from neutron-induced fission of 235U, 238U, and 239Pu. Despite decades of fission research, little or no TKE data exist for high incident neutron energies. Additional average TKE information at incident neutron energies relevant to defense- and energy-related applications will provide a valuable observable for benchmarking simulations. The data can also be used as inputs in theoretical fission models. The Los Alamos Neutron Science Center-Weapons Neutron Research (LANSCE - WNR) provides a neutron beam from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on 238U, 235U, and 239Pu will be presented. LA-UR-14-24921.

  6. Measurement of fallout {sup 239}Pu levels in urine samples by fission track analysis

    SciTech Connect

    Moorthy, A.R.; Doty, R.M.

    1996-11-01

    A Fission Track Analysis (FTA) method for assessing 239Pu in urine samples was first developed at Brookhaven National Laboratory (BNL) in 1988; it then had a detection limit of 100 aCi (3.7 {micro}Bq). Since that time, several steps were introduced that increased chemical recovery and lowered the detection limit to less than 1O aCi per sample. These improvements include a process of micro-column separation of plutonium in the final stages. The improved FTA method was applied to 22 urine samples from male staff at BNL. The results showed that 239Pu from fallout excreted in urine was 33 +/- 11 aCi (1.2 {micro}Bq) per day.

  7. Alveolar deposition of sized particles of /sup 239/Pu0/sub 2/ in the mouse

    SciTech Connect

    Morgan, A.; Black, A; Moores, S.R.; Pritchard, J.N.; Walsh, M.; Lambert, B.E.

    1983-01-01

    Data on the alveolar deposition of /sup 239/PuO/sub 2/ particles in the mouse are presented. It is shown that alveolar deposition falls with increasing activity median aerodynamic diameter (AMAD) over the range 0.6 to 2.4 ..mu..m. In the mouse, any peak in alveolar deposition must occur at an AMAD of less than 1 ..mu..m. Information is also provided on the relative lobar concentrations (RLCs) of /sup 239/PuO/sub 2/. The RLC is greatest in the right apical lobe and increases quite sharply with AMAD. The RLCs of the other lobes of the right lung decline with AMAD. The RLC in the left lobe is relatively unaffected by AMAD.

  8. Alveolar deposition of sized particles of /sup 239/PuO/sub 2/ in the mouse

    SciTech Connect

    Morgan, A.; Black, A.; Moores, S.R.; Pritchard, J.N.; Walsh, M.; Lambert, B.E.

    1983-01-01

    Data on the alveolar deposition of /sup 239/PuO/sub 2/ particles in the mouse are presented. It is shown that alveolar deposition falls with increasing activity median aerodynamic diameter (AMAD) over the range 0.6 to 2.4 microns. In the mouse, any peak in alveolar deposition must occur at an AMAD of less than 1 micron. Information is also provided on the relative lobar concentrations (RLCs) of /sup 239/PuO/sub 2/. The RLC is greatest in the right apical lobe and increases quite sharply with AMAD. The RLCs of the other lobes of the right lung decline with AMAD. The RLC in the left lobe is relatively unaffected by AMAD.

  9. A Time Projection Chamber for precision 239Pu(n,f) cross section measurement

    SciTech Connect

    Heffner, M

    2008-01-14

    High precision measurements of the {sup 239}Pu(n,f) cross section have been identified as important for the Global Nuclear Energy Partnership (GNEP) and other programs. Currently the uncertainty on this cross section is of the order 2-3% for neutron energies below 14 MeV and the goal is to reduce this to less than 1%. The Time Projection Chamber (TPC) has been identified as a possible tool to make this high precision measurement.

  10. Presence of plutonium isotopes, 239Pu and 240Pu, in soils from Chile

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Peruchena, J. I.; Cereceda, F.; Vidal, V.; Pinilla, E.; Miró, C.

    2011-12-01

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global 239Pu and 240Pu environmental inventory, with an important contribution of the so-called tropospheric fallout from both the atmospheric nuclear tests performed in the French Polynesia and in Australia by France and United Kingdom, respectively. In this work we provide new data on the impact of these tests to South America through the study of 239Pu and 240Pu in soils from different areas of Northern, Central and Southern Chile. The obtained results point out to the presence of debris from the French tests in the 20-40° Southern latitude range, with 240Pu/ 239Pu atomic ratios quite heterogeneous and ranging from 0.02 to 0.23. They are significantly different from the expected one for the global fallout in the Southern Hemisphere for the 30-53°S latitude range (0.185 ± 0.047), but they follow the same trend as the reported values by the Department of Energy of United States for other points with similar latitudes. The 239 + 240Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

  11. Carcinogenic interactions between a single inhalation of 239PuO2 and chronic exposure to cigarette smoke in rats.

    PubMed

    Mauderly, Joe L; Seilkop, Steven K; Barr, Edward B; Gigliotti, Andrew P; Hahn, Fletcher F; Hobbs, Charles H; Finch, Gregory L

    2010-05-01

    Rats were exposed once by inhalation to plutonium-239 dioxide ((239)PuO(2)), resulting in chronic alpha-particle irradiation of the lung, and exposed chronically to cigarette smoke to examine carcinogenic interactions between the two exposures. F344 rats were exposed to (239)PuO(2) to achieve an initial lung burden of 0.5 kBq and then exposed 6 h/day, 5 days/week to cigarette smoke at 100 or 250 mg particulate matter/m(3) for up to 30 months. Exposure to cigarette smoke increased the cumulative radiation dose to lung by slowing the clearance of (239)PuO(2). (239)PuO(2) alone did not affect survival, but the higher cigarette smoke exposure shortened survival in females. Combined exposure to (239)PuO(2) and cigarette smoke acted synergistically to shorten survival in both genders. The combined effects of cigarette smoke and (239)PuO(2) were approximately additive for lung hyperplasia and adenomas but were strongly synergistic for carcinomas. Differences between observed incidences and incidences predicted by survival-adjusted models accounting for increased radiation dose revealed a substantial component of synergy for carcinomas above that attributable to the radiation dose effect. The synergy for malignant lung tumors is consistent with findings from uranium miners and nuclear weapons production workers. These results bolster confidence in the epidemiological findings and have implications for risk assessment. PMID:20426667

  12. Nevada test site fallout atom ratios: /sup 240/Pu//sup 239/Pu and /sup 241/Pu//sup 239/Pu

    SciTech Connect

    Hicks, H.G.; Barr, D.W.

    1984-02-01

    The exposure of the population in Utah to external gamma radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site (NTS) has been reconstructed from recent measurements of /sup 137/Cs and plutonium in soil. The fraction of /sup 137/Cs in the fallout from NTS events was calculated from the total plutonium and the /sup 240/Pu//sup 239/Pu ratios measured in the soil, using the values of 0.180 +- 0.006 and 0.032 +- 0.003 for that ratio in global fallout and NTS fallout, respectively. The total population exposure from NTS events was then calculated on the basis of exposure rates resulting from short-lived radionuclides associated with the /sup 137/Cs at the time of deposition. While the /sup 240/Pu//sup 239/Pu ratio is constant in global fallout, this ratio varies greatly in the fallout from individual events. While the composition of fallout on Utah from NTS events is rather uniform, the Off-Site Radiation Exposure Review Project is currently reconstructing radiation exposures for locations close to NTS where the fallout may be predominantly from one event. Therefore, the authors compiled the pertinent ratios in order to provide information concerning the exposure resulting from any individual event. The plutonium ratios measured at 30 days postshot were compiled from unpublished values in the archives of the Nuclear Chemistry Division of LLNL and INC-11 of LANL. These ratios are pertinent to fallout data. Dates for each event were taken from a publication by the Nevada Operations Office of the Department of Energy. 3 references.

  13. 239PU(N, f) at Resonance Energies and its Multi-Modal Interpretation

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.; Bax, H.; Ruskov, I.; Demattè, L.

    2003-10-01

    A measurement of fission fragment total kinetic energy (TKE) and mass yield distributions Y (A,TKE) in the 239Pu(n,f) resolved resonance region has been performed applying the twin Frisch gridded ionization chamber technique. Special emphasis was devoted to cope with the strong α-activity of this isotope by an improved pile-up rejection system. Up to about 200 eV all fission resonances could be resolved and their two-dimensional mass yield and TKE distribution, Y(A,TKE), measured. Compared to the results on 235U(n,f), much smaller fluctuations of the fission fragment mass and TKE have been observed in the case of 239Pu. From a physical point of view such fluctuations have been expected for the fission fragment properties, because the only possible lowenergy spin states (Jπ=0+,1+) belong to well separated (about 1.25 MeV) transition state bands. Hence, it was expected to observe differences in the fission fragment mass and TKE distributions between spin 0+ and 1+ resonances. However, no spin dependence and only a slight anti-correlation of the TKE with the prompt neutron multiplicity, νp. has been found in the resolved resonance energy region above 1 eV. Within the multi-modal random neck-rupture (MM-RNR) model the Y(A,TKE) distributions have been fitted assuming three fission modes, two asymmetric and one symmetric one. The branching ratio of the two asymmetric modes shows similar fluctuations as the experimental TKE. Recently, a new theoretical approach has given a solution to the absence of pronounced fluctuations of the fission properties in the case of 239Pu. Since only one transition state is involved in the fission of 0+ and 1+ resonances with a given fission fragment distribution, no fluctuations are expected.

  14. Commentary on Inhaled 239PuO2 in Dogs — A Prophylaxis against Lung Cancer?

    DOE PAGESBeta

    Cuttler, Jerry M.; Feinendegen, Ludwig E.

    2015-01-01

    Several studies on the effect of inhaled plutonium-dioxide particulates and the incidence of lung tumors in dogs reveal beneficial effects when the cumulative alpha-radiation dose is low. There is a threshold at an exposure level of about 100 cGy for excess tumor incidence and reduced lifespan. The observations conform to the expectations of the radiation hormesis dose-response model and contradict the predictions of the LNT hypothesis. These studies suggest investigating the possibility of employing low-dose alpha-radiation, such as from 239PuO2 inhalation, as a prophylaxis against lung cancer.

  15. Improving the Assay of 239Pu in Spent and Melted Fuel Using the Nuclear Resonance Fluorescence Integral Resonance Transmission Method

    NASA Astrophysics Data System (ADS)

    Angell, C. T.; Hayakawa, T.; Shizuma, T.; Hajima, R.; Quiter, B. J.; Ludewigt, B. A.; Karwowski, H.; Rich, G.

    2015-10-01

    Non-destructive assay (NDA) of 239Pu in spent nuclear fuel is possible using the isotope-specific nuclear resonance fluorescence (NRF) integral resonance transmission (IRT) method. The IRT method measures the absorption of photons from a quasi-monoenergetic γ-ray beam due to all resonances in the energy width of the beam. According to calculations the IRT method could greatly improve assay times for 239Pu in nuclear fuel. To demonstrate and verify the IRT method, the IRT signature was first measured in 181Ta, whose nuclear resonant properties are similar to those of 239Pu, and then measured in 239Pu. These measurements were done using the quasi-monoenergetic beam at the High Intensity γ-ray Source (HIγS) in Durham, NC, USA. The IRT signature was observed as a decrease in scattering strength when the same isotope material was placed upstream of the scattering target. The results confirm the validity of the IRT method in both 181Ta and 239Pu.

  16. Consistent Data Assimilation of Actinide Isotopes: 235U and 239Pu

    SciTech Connect

    G. Palmiottti; H. Hiruta; M. Salvatores

    2011-09-01

    In this annual report we illustrate the methodology of the consistent data assimilation that allows to use the information coming from integral experiments for improving the basic nuclear parameters used in cross section evaluation. A series of integral experiments were analyzed using the EMPIRE evaluated files for {sup 235}U, {sup 238}U, and {sup 239}Pu. Inmost cases the results have shown quite large worse results with respect to the corresponding existing evaluations available for ENDF/B-VII. The observed discrepancies between calculated and experimental results were used in conjunction with the computed sensitivity coefficients and covariance matrix for nuclear parameters in a consistent data assimilation. Only the GODIVA and JEZEBEL experimental results were used, in order to exploit information relative to the isotope of interest that are, in this particular case: {sup 235}U and {sup 239}Pu. The results obtained by the consistent data assimilation indicate that with reasonable modifications (mostly within the initial standard deviation) it is possible to eliminate the original large discrepancies on the K{sub eff} of the two critical configurations. However, some residual discrepancy remains for a few fission spectral indices that are, most likely, to be attributed to the detector cross sections.

  17. Partial (gamma)-Ray Cross Sections for the Reaction 239Pu(n,2n(gamma)i) and the 239Pu(n,2n) Cross Section

    SciTech Connect

    Beacker, J.A.; Bernstein, L.A.; Younes, W.; McNabb, D.P.; Garrett, P.E.; Archer, D.; McGrath, C.A.; Stoyer, M.A.; Chen, H.; Ormand, W.E.; Nelson, R.O.; Chadwick, M.B.; Johns, G.D.; Drake, D.; Young, P.G.; Devlin, M.; Fotiades, N.; Wilburn, W.S.

    2001-09-14

    Absolute partial {gamma}-ray cross sections for production of discrete {gamma} rays in the {sup 239}Pu(n,2n{gamma}i){sup 238}Pu reaction have been measured. The experiments were performed at LANSCE/WNR on the 60R flight line. Reaction {gamma}-rays were measured using the large-scale Compton-suppressed array of Ge detectors, GEANIE. The motivation for this experiment, an overview of the partial {gamma}-ray cross-section measurement, and an introduction to the main experimental issues will be presented. The energy resolution of the Ge detectors allowed identification of reaction {gamma} rays above the background of sample radioactivity and fission {gamma} rays. The use of planar Ge detectors with their reduced sensitivity to neutron interactions and improved line shape was also important to the success of this experiment. Absolute partial {gamma}-ray cross sections are presented for the 6{sub 1}{sup +} {yields} 4{sub 1}{sup +} member of the ground state rotational band in {sup 238}Pu, together with miscellaneous other {gamma}-ray partial cross sections. The n,2n reaction cross section shape and magnitude as a function of neutron energy was extracted from these partial cross sections using nuclear modeling (enhanced Hauser-Feshbach) to relate partial {gamma}-ray cross sections to the n,2n cross section. The critical nuclear modeling issue is the ratio of a partial cross section to the reaction channel cross section, and not the prediction of the absolute magnitude.

  18. 239Pu(n,2n) 238Pu cross section inferred from IDA calculations and GEANIE measurements

    SciTech Connect

    Chen, H; Ormand, W E; Dietrich, F S

    2000-09-01

    This report presents the latest {sup 239}Pu(n,2n){sup 238}Pu cross sections inferred from calculations performed with the nuclear reaction-modeling code system, IDA, coupled with experimental measurements of partial {gamma}-ray cross sections for incident neutron energies ranging from 5.68 to 17.18 MeV. It is found that the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section peaks at E{sub inc} {approx} 11.4 MeV with a peak value of approximately 326 mb. At E{sub inc} {approx} 14 MeV, the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section is found to be in good agreement with previous radio-chemical measurements by Lockheed. However, the shape of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section differs significantly from previous evaluations of ENDL, ENDF/B-V and ENDF/B-VI. In our calculations, direct, preequilibrium, and compound reactions are included. Also considered in the modeling are fission and {gamma}-cascade processes in addition to particle emission. The main components of physics adopted and the parameters used in our calculations are discussed. Good agreement of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross sections derived separately from IDA and GNASH calculations is shown. The two inferences provide an estimate of variations in the deduced {sup 239}Pu(n,2n){sup 238}Pu cross section originating from modeling.

  19. Alpha and conversion electron spectroscopy of 238,239Pu and 241Am and alpha-conversion electron coincidence measurements

    NASA Astrophysics Data System (ADS)

    Dion, Michael P.; Miller, Brian W.; Warren, Glen A.

    2016-09-01

    A technique to determine the isotopic constituents of a mixed actinide sample has been proposed by a coincident alpha-conversion electron measurement. This presents a unique signature to allow the unfolding of isotopes that possess overlapping alpha particle energy and reduce backgrounds of an unseparated sample. The work presented here are results of conversion electron spectroscopy of 241Am, 238Pu and 239Pu using a dual-stage peltier-cooled 25 mm2 silicon drift detector and alpha spectroscopy with a passivated ion implanted planar silicon detector. The conversion electron spectra were evaluated from 20-55 keV based on fits to the dominant conversion electron emissions, which allowed the relative conversion electron emission intensities to be determined. These measurements provide crucial singles spectral information and calibration to aid in the coincident measurement approach. Furthermore, an alpha-conversion electron spectrometer was assembled using the silicon based detectors described and results of a coincident spectrum analysis is reported for 241Am.

  20. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

  1. Quantitative scanning electron microscopic autoradiography of inhaled /sup 239/PuO/sub 2/

    SciTech Connect

    Sanders, C.L.; Lauhala, K.E.; McDonald, K.E.

    1989-03-01

    We have applied the scanning electron microscope (SEM) to obtain autoradiographs of particles of /sup 239/PuO/sub 2/ deposited in rat lung. The technique was used to obtain quantitative information on the clearance rates of particles from the alveoli, bronchioles and trachea up to 240 d after exposure. At all times, the concentration of particles on the surface of the bronchioles was an order of magnitude greater than on the tracheal surface. The clearance of Pu from both regions followed a biphasic pattern, similar to that obtained by radiometric analysis of the whole lung. Most of the radiation dose to the bronchiolar epithelium originated from Pu particles in peribronchiolar alveoli in which they were preferentially retained, compared to other alveolar regions. The prolonged retention of particles in the peribronchiolar alveoli may be a significant factor in the induction of lung carcinomas.

  2. Calculation of 239Pu fission observables in an event-by-event simulation

    SciTech Connect

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2010-03-31

    The increased interest in more exclusive fission observables has demanded more detailed models. We describe a new computational model, FREYA, that aims to meet this need by producing large samples of complete fission events from which any observable of interest can then be extracted consistently, including any interesting correlations. The various model assumptions are described and the potential utility of the model is illustrated. As a concrete example, we use formal statistical methods, experimental data on neutron production in neutron-induced fission of {sup 239}Pu, along with FREYA, to develop quantitative insights into the relation between reaction observables and detailed microscopic aspects of fission. Current measurements of the mean number of prompt neutrons emitted in fission taken together with less accurate current measurements for the prompt post-fission neutron energy spectrum, up to the threshold for multi-chance fission, place remarkably fine constraints on microscopic theories.

  3. 239Pu Prompt Fission Neutron Spectra Impact on a Set of Criticality and Experimental Reactor Benchmarks

    NASA Astrophysics Data System (ADS)

    Peneliau, Y.; Litaize, O.; Archier, P.; De Saint Jean, C.

    2014-04-01

    A large set of nuclear data are investigated to improve the calculation predictions of the new neutron transport simulation codes. With the next generation of nuclear power plants (GEN IV projects), one expects to reduce the calculated uncertainties which are mainly coming from nuclear data and are still very important, before taking into account integral information in the adjustment process. In France, future nuclear power plant concepts will probably use MOX fuel, either in Sodium Fast Reactors or in Gas Cooled Fast Reactors. Consequently, the knowledge of 239Pu cross sections and other nuclear data is crucial issue in order to reduce these sources of uncertainty. The Prompt Fission Neutron Spectra (PFNS) for 239Pu are part of these relevant data (an IAEA working group is even dedicated to PFNS) and the work presented here deals with this particular topic. The main international data files (i.e. JEFF-3.1.1, ENDF/B-VII.0, JENDL-4.0, BRC-2009) have been considered and compared with two different spectra, coming from the works of Maslov and Kornilov respectively. The spectra are first compared by calculating their mathematical moments in order to characterize them. Then, a reference calculation using the whole JEFF-3.1.1 evaluation file is performed and compared with another calculation performed with a new evaluation file, in which the data block containing the fission spectra (MF=5, MT=18) is replaced by the investigated spectra (one for each evaluation). A set of benchmarks is used to analyze the effects of PFNS, covering criticality cases and mock-up cases in various neutron flux spectra (thermal, intermediate, and fast flux spectra). Data coming from many ICSBEP experiments are used (PU-SOL-THERM, PU-MET-FAST, PU-MET-INTER and PU-MET-MIXED) and French mock-up experiments are also investigated (EOLE for thermal neutron flux spectrum and MASURCA for fast neutron flux spectrum). This study shows that many experiments and neutron parameters are very sensitive to

  4. Prompt Gamma Emission in Resonance Neutron Induced Fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Ruskov, I.; Kopatch, Yu. N.; Panteleev, Ts.; Skoy, V. R.; Shvetsov, V. N.; Dermendjiev, E.; Janeva, N.; Pikelner, L. B.; Grigoriev, Yu. V.; Mezentseva, Zh. V.; Ivanov, I.

    The scientific interest in the resonance neutron induced capture and fission reactions on 239Pu is continuously rising during the last decade. From a practical point of view, this is because more precise data on capture and fission cross sections, fission fragment mass and kinetic energy distributions, variation of prompt fission neutron and gamma yields in the resonance neutron region, are needed for the modelling of new generation nuclear power plants and for nuclear spent fuel and waste transmutation. From a heuristic and fundamental point of view, such a research improves our knowledge and understanding of the fission phenomena itself. To achieve these goals more powerful neutron sources and more precise fission product detectors have to be used. At the Joint Institute for Nuclear Research (JINR) Frank Laboratory of Neutron Physics (FLNP), where already half a century the thermal and resonance neutron induced nuclear reactions are studied, a new electron accelerator driven white spectrum pulsed neutron source IREN has been built and successfully tested. The improved characteristics of this facility, in comparison with those of the former pulse neutron fast reactor IBR-30, will allow measuring some of the neutron-nuclear reaction data with better precision and accuracy. A new experimental setup for detecting gamma rays (and neutrons) has been designed and is under construction. It will consist of 2 rings (arrays) of 12 NaI(Tl) detectors each (or 1 array of 24 detectors) with variable ring diameter and distance between both rings. Such a setup will make possible not only to measure the multiplicity, energy and angular anisotropy of prompt fission gammas, but also to separate the contribution of prompt fission neutrons by their longer time-of-flight from the fissile target to the detectors. The signals from all the 24 detectors will be recorded simultaneously in digitized form and will be stored on the hard disk of the personal computer for further off

  5. Distribution of /sup 239/Pu and /sup 241/Am in the human skeleton

    SciTech Connect

    McInroy, J.F.; Swint, M.J.

    1984-01-01

    The /sup 241/Am and /sup 239/Pu distribution in the skeletons of two former nuclear workers has been measured. The skeletons of both individuals appear to be within normal limits for Caucasian men about 50 y old. Both had lower limb bones that were heavier than the age controls and Case I had upper-body bones that were lighter than the age control group. The distribution of americium in the skeleton of Case I, 25 years post exposure, indicated that a more rapid turnover of initially deposited americium on the bone surfaces of cancellous bone, as compared to that deposited on the bone surfaces of compact bone, had occurred. This resulted in a larger proportion of americium located in the compact bone of the extremities and a lesser quantity in the more cancellous bones of the vertebral column, pelvis and rib cage. A similar shift in the distribution of plutonium occurred in Case II in the 35 y since initial deposition, but at a slower rate than that for americium. The ratio of each actinide in the liver to that in the systemic system (liver content/systemic system content) was 0.065 and 0.436, for americium and plutonium, respectively, suggesting that a much more rapid turnover of americium in the liver, compared to plutonium, provided a much larger fraction of that nuclide for circulatory feedback to the remodeling skeletal system. 8 references, 3 tables.

  6. [Acceleration of the excretion of monomeric 239Pu-citrate from the body as effected by pentacyne encapsulated in liposomes].

    PubMed

    Il'in, L A; Smirnov, A A; Ivannikov, A T; Parfenova, I M

    1983-01-01

    Liposomes, obtained by a modified procedure involving reverse phases, contained 2-3-times more 14C-pentacyne than the multilayer Banchem;s liposomes. Efficiency of pentacyne encapsulated in liposomes was higher, as compared with a non-encapsulated preparation in studies of urinary excretion of monomeric 239Pu-citrate in rats. Liposomal pentacyne increased most effectively the rate of the radionuclide excretion from liver tissue and skeleton as compared with the action of non-encapsulated complex-forming agent; as a result of which the radionuclide was excreted from liver tissue at a 1.6-2-times and from skeleton--with the 1.4-times higher rates. The both preparations increased the 239Pu excretion with urine and feces. The liposomal pentacyne accelerated an additional excretion of the nuclide with urine. PMID:6353751

  7. Probing energy dissipation, γ-ray and neutron multiplicity in the thermal neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Pahlavani, M. R.; Mirfathi, S. M.

    2016-04-01

    The incorporation of the four-dimensional Langevin equations led to an integrative description of fission cross-section, fragment mass distribution and the multiplicity and energy distribution of prompt neutrons and γ-rays in the thermal neutron-induced fission of 239Pu. The dynamical approach presented in this paper thoroughly reproduces several experimental observables of the fission process at low excitation energy.

  8. Fission Product Yields for 14 MeV Neutrons on 235U, 238U and 239Pu

    NASA Astrophysics Data System (ADS)

    Mac Innes, M.; Chadwick, M. B.; Kawano, T.

    2011-12-01

    We report cumulative fission product yields (FPY) measured at Los Alamos for 14 MeV neutrons on 235U, 238U and 239Pu. The results are from historical measurements made in the 1950s-1970s, not previously available in the peer reviewed literature, although an early version of the data was reported in the Ford and Norris review. The results are compared with other measurements and with the ENDF/B-VI England and Rider evaluation. Compared to the Laurec (CEA) data and to ENDF/B-VI evaluation, good agreement is seen for 235U and 238U, but our FPYs are generally higher for 239Pu. The reason for the higher plutonium FPYs compared to earlier Los Alamos assessments reported by Ford and Norris is that we update the measured values to use modern nuclear data, and in particular the 14 MeV 239Pu fission cross section is now known to be 15-20% lower than the value assumed in the 1950s, and therefore our assessed number of fissions in the plutonium sample is correspondingly lower. Our results are in excellent agreement with absolute FPY measurements by Nethaway (1971), although Nethaway later renormalized his data down by 9% having hypothesized that he had a normalization error. The new ENDF/B-VII.1 14 MeV FPY evaluation is in good agreement with our data.

  9. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U

    NASA Astrophysics Data System (ADS)

    Selby, H. D.; Mac Innes, M. R.; Barr, D. W.; Keksis, A. L.; Meade, R. A.; Burns, C. J.; Chadwick, M. B.; Wallstrom, T. C.

    2010-12-01

    where the present results are about 4%-relative higher for neutrons incident on 239Pu and 235U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the 147Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

  10. Reactor Decay Heat in {sup 239}Pu: Solving the {gamma} Discrepancy in the 4-3000-s Cooling Period

    SciTech Connect

    Algora, A.; Jordan, D.; Tain, J. L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A. B.; Molina, F.; Caballero, L.; Nacher, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L.; Aeysto, J.; Penttilae, H.; Moore, I. D.; Eronen, T.; Jokinen, A.

    2010-11-12

    The {beta} feeding probability of {sup 102,104,105,106,107}Tc, {sup 105}Mo, and {sup 101}Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the {gamma} component of the decay heat for {sup 239}Pu in the 4-3000 s range.

  11. Energy dependence of mass, charge, isotopic, and energy distributions in neutron-induced fission of 235U and 239Pu

    NASA Astrophysics Data System (ADS)

    Pasca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kim, Y.

    2016-05-01

    The mass, charge, isotopic, and kinetic-energy distributions of fission fragments are studied within an improved scission-point statistical model in the reactions 235U+n and 239Pu+n at different energies of the incident neutron. The charge and mass distributions of the electromagnetic- and neutron-induced fission of 214,218Ra, 230,232,238U are also shown. The available experimental data are well reproduced and the energy-dependencies of the observable characteristics of fission are predicted for future experiments.

  12. Reactor decay heat in 239Pu: solving the γ discrepancy in the 4-3000-s cooling period.

    PubMed

    Algora, A; Jordan, D; Taín, J L; Rubio, B; Agramunt, J; Perez-Cerdan, A B; Molina, F; Caballero, L; Nácher, E; Krasznahorkay, A; Hunyadi, M D; Gulyás, J; Vitéz, A; Csatlós, M; Csige, L; Aysto, J; Penttilä, H; Moore, I D; Eronen, T; Jokinen, A; Nieminen, A; Hakala, J; Karvonen, P; Kankainen, A; Saastamoinen, A; Rissanen, J; Kessler, T; Weber, C; Ronkainen, J; Rahaman, S; Elomaa, V; Rinta-Antila, S; Hager, U; Sonoda, T; Burkard, K; Hüller, W; Batist, L; Gelletly, W; Nichols, A L; Yoshida, T; Sonzogni, A A; Peräjärvi, K

    2010-11-12

    The β feeding probability of (102,104,105,106,107)Tc, 105Mo, and 101Nb nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the γ component of the decay heat for 239Pu in the 4-3000 s range. PMID:21231223

  13. Mass Yields and Average Total Kinetic Energy Release in Fission for 235U, 238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Duke, Dana

    2015-10-01

    Mass yield distributions and average total kinetic energy (TKE) in neutron induced fission of 235U, 238U, and 239Pu targets were measured with a gridded ionization chamber. Despite decades of fission research, our understanding of how fragment mass yields and TKE depend on incident neutron energy is limited, especially at higher energies (above 5-10 MeV). Improved accuracy in these quantities is important for nuclear technology as it enhances our simulation capabilities and increases the confidence in diagnostic tools. The data can also guide and validate theoretical fission models where the correlation between the fragment mass and TKE is of particular value for constraining models. The Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE - WNR) provides a neutron beam with energies from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on target nuclei 235U, 238U, and 239Pu will be presented with a focus on exploring data trends as a function of neutron energy from thermal through 30 MeV. Results indicate clear evidence of structure due to multi-chance fission in the TKE . LA-UR-15-24761.

  14. Accelerator Mass Spectrometric (AMS) Measurements of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios In Soil Extracts Supplied by the Carlsbad Environmental Monitoring & Research Center

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-02-28

    Plutonium-239 ({sup 239}Pu) and plutonium-239+240 ({sup 239+240}Pu) activities concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for a series of chemically purified soil extracts received from the Carlsbad Environmental Monitoring & Research Center (CEMRC) in New Mexico. Samples were analyzed without further purification at the Lawrence Livermore National Laboratory (LLNL) using accelerator mass spectrometry (AMS). This report also includes a brief description of the AMS system and internal laboratory procedures used to ensure the quality and reliability of the measurement data.

  15. Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

    SciTech Connect

    Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

    2010-03-16

    This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment of

  16. Microdistribution and Long-Term Retention of 239Pu (NO3)4 in the Respiratory Tracts of an Acutely Exposed Plutonium Worker and Experimental Beagle Dogs

    SciTech Connect

    Nielsen, Christopher E.; Wilson, Dulaney A.; Brooks, Antone L.; McCord, Stacey; Dagle, Gerald E.; James, Anthony C.; Tolmachev, Sergei Y.; Thrall, Brian D.; Morgan, William F.

    2012-11-01

    The long-term retention of inhaled soluble forms of plutonium raises concerns as to the potential health effects in persons working in nuclear energy or the nuclear weapons program. The distributions of long-term retained inhaled plutonium-nitrate [239Pu (NO3)4] deposited in the lungs of an accidentally exposed nuclear worker (Human Case 0269) and in the lungs of experimentally exposed beagle dogs with varying initial lung depositions were determined via autoradiographs of selected histological lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a non-uniform distribution of plutonium throughout the lung tissue. Fibrotic scar tissue effectively encapsulated a portion of the plutonium and prevented its clearance from the body or translocation to other tissues and diminished dose to organ parenchyma. Alpha radiation activity from deposited plutonium in Human Case 0269 was observed primarily along the sub-pleural regions while no alpha activity was seen in the tracheobronchial lymph nodes of this individual. However, relatively high activity levels in the tracheobronchial lymph nodes of the beagles indicated the lymphatic system was effective in clearing deposited plutonium from the lung tissues. In both the human case and beagle dogs, the appearance of retained plutonium within the respiratory tract was inconsistent with current biokinetic models of clearance for soluble forms of plutonium. Bound plutonium can have a marked effect on the dose to the lungs and subsequent radiation exposure has the potential increase in cancer risk.

  17. Inhaled /sup 239/PuO/sub 2/ and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

    SciTech Connect

    Filipy, R.E.; Decker, J.R.; Lai, Y.L.; Lauhala, K.E.; Buschbom, R.L.; Hiastala, M.P.; McGee, D.R.; Park, J.F.; Kuffel, E.G.; Ragan, H.A.; Cannon, W.C.; Yaniv, S.S.; Scott, B.R.

    1988-08-01

    Rats and beagle dogs were given doses of /sup 60/Co gamma radiation and/or body burdens of /sup 239/PuO/sub 2/ within lethal ranges in an experiment to determine and compare morbidity and mortality responses of both species within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell concentrations and by long-term loss of body weight and diminished pulmonary function in animals of both species that survived the acute gamma radiation syndrome. Inhaled plutonium caused a loss of body weight and diminished pulmonary function in both species, but its only effect on blood cell concentrations was lymphocytopenia in dogs. Combined gamma irradiation and plutonium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Plutonium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the long-term effect of plutonium lung burdens in both species. Rats were less sensitive to both kinds of radiation, whether administered alone or in combination. 71 refs., 105 figs., 48 tabs.

  18. Photofission and photoneutron cross sections and photofission neutron multiplicities for /sup 233/U, /sup 234/U, /sup 237/Np, and /sup 239/Pu

    SciTech Connect

    Berman, B.L.; Caldwell, J.T.; Dowdy, E.J.; Dietrich, S.S.; Meyer, P.; Alvarez, R.A.

    1986-12-01

    The photonuclear cross sections for /sup 233/U, /sup 234/U, /sup 237/Np, and /sup 239/Pu have been measured from threshold up to 18 MeV. The source of radiation was the monoenergetic photon beam from the annihilation in flight of fast positrons. The branching among the neutron-producing reaction channels was determined by measuring the photofission prompt neutron multiplicities nu-bar/sub p/. One interesting result is the complete absence of any (..gamma..,2n) cross section for /sup 233/U and /sup 234/U. The values of nu-bar/sub p/(E) for /sup 234/U agree with those measured with neutrons incident on /sup 233/U. The parameters of the giant dipole resonance deduced from the total photonuclear cross sections show that these nuclei have large static deformations, as expected. The integrated photofission cross sections are large (as are the absolute fission probabilities), and account for 60% to 80% of the total photonuclear absorption strength.

  19. Microdistribution and long-term retention of 239Pu (NO3)4 in the respiratory tracts of an acutely exposed plutonium worker and experimental beagle dogs.

    PubMed

    Nielsen, Christopher E; Wilson, Dulaney A; Brooks, Antone L; McCord, Stacey L; Dagle, Gerald E; James, Anthony C; Tolmachev, Sergei Y; Thrall, Brian D; Morgan, William F

    2012-11-01

    The long-term retention of inhaled soluble forms of plutonium raises concerns as to the potential health effects in persons working in nuclear energy or the nuclear weapons program. The distributions of long-term retained inhaled plutonium-nitrate [(239)Pu (NO(3))(4)] deposited in the lungs of an accidentally exposed nuclear worker (Human Case 0269) and in the lungs of experimentally exposed beagle dogs with varying initial lung depositions were determined via autoradiographs of selected histologic lung, lymph node, trachea, and nasal turbinate tissue sections. These studies showed that both the human and dogs had a nonuniform distribution of plutonium throughout the lung tissue. Fibrotic scar tissue effectively encapsulated a portion of the plutonium and prevented its clearance from the body or translocation to other tissues and diminished dose to organ parenchyma. Alpha radiation activity from deposited plutonium in Human Case 0269 was observed primarily along the subpleural regions while no alpha activity was seen in the tracheobronchial lymph nodes of this individual. However, relatively high activity levels in the tracheobronchial lymph nodes of the beagles indicated the lymphatic system was effective in clearing deposited plutonium from the lung tissues. In both the human case and beagle dogs, the appearance of retained plutonium within the respiratory tract was inconsistent with current biokinetic models of clearance for soluble forms of plutonium. Bound plutonium can have a marked effect on the dose to the lungs and subsequent radiation exposure has the potential to increase cancer risk. PMID:22962267

  20. Evaluating the 239Pu Prompt Fission Neutron Spectrum Induced by Thermal to 30 MeV Neutrons

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Talou, P.; Kawano, T.; Kahler, A. C.; Rising, M. E.; White, M. C.

    2016-03-01

    We present a new evaluation of the 239Pu prompt fission neutron spectrum (PFNS) induced by thermal to 30 MeV neutrons. Compared to the ENDF/B-VII.1 evaluation, this one includes recently published experimental data as well as an improved and extended model description to predict PFNS. For instance, the pre-equilibrium neutron emission component to the PFNS is considered and the incident energy dependence of model parameters is parametrized more realistically. Experimental and model parameter uncertainties and covariances are estimated in detail. Also, evaluated covariances are provided between all PFNS at different incident neutron energies. Selected evaluation results and first benchmark calculations using this evaluation are briefly discussed.

  1. Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n,f)

    NASA Astrophysics Data System (ADS)

    Vogt, R.; Randrup, J.; Brown, D. A.; Descalle, M. A.; Ormand, W. E.

    2012-02-01

    Earlier studies of 239Pu(n,f) have been extended to incident neutron energies up to 20 MeV within the framework of the event-by-event fission model FREYA, into which we have incorporated multichance fission and pre-equilibrium neutron emission. The main parameters controlling prompt fission neutron evaporation have been identified and the prompt fission neutron spectrum has been analyzed by fitting those parameters to the average neutron multiplicity ν¯ from ENDF-B/VII.0, including the energy-energy correlations in the covariance of ν¯(E) obtained by fitting to the experimental ν¯ data used in the ENDF-B/VII.0 evaluation. We present our results, discuss relevant tests of this new evaluation, and describe possible further improvements.

  2. 137Cs, 239+240Pu and 240Pu/239Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas.

    PubMed

    Yamada, Masatoshi; Zheng, Jian; Wang, Zhong-Liang

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The (137)Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The (137)Cs activities showed a wide variation with values ranging from 1.1 Bq m(-3) in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m(-3) in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of (137)Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of (137)Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of (137)Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr(-1) in the Sulu and Indonesian Seas, 0.033 yr(-1) in the Bay of Bengal and Andaman Sea, and 0.029 yr(-1) in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. (239+240)Pu activities and (240)Pu/(239)Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The (240)Pu/(239)Pu atom ratios ranged from 0.199+/-0.026 to 0.248+/-0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using the two end-member mixing model. The higher (240)Pu/(239)Pu

  3. Perturbation in the 240Pu/239Pu global fallout ratio in local sediments following the nuclear accidents at Thule (Greenland) and Palomares (Spain).

    PubMed

    Mitchell, P I; León Vintró, L; Dahlgaard, H; Gascó, C; Sánchez-Cabeza, J A

    1997-08-25

    It is well established that the main source of the plutonium found in marine sediments throughout the Northern Hemisphere is global stratospheric fallout, characterized by a typical 240Pu/239Pu atom ratio of approximately 0.18. Measurement of perturbations in this ratio at various sites which had been subjected to close-in fallout, mainly from surface-based testing (e.g. Bikini Atoll, Nevada test site, Mururoa Atoll), has confirmed the feasibility of using this ratio to distinguish plutonium from different fallout sources. In the present study, the 240Pu/239Pu ratio has been examined in samples of sediment (and soil) collected at Thule (Greenland) and Palomares (Spain), where accidents involving the release and dispersion of plutonium from fractured nuclear weapons occurred in 1968 and 1966, respectively. The 240Pu/239Pu ratio was measured by high-resolution alpha spectrometry and spectral deconvolution, and confirmed in the case of the most active samples by high-resolution X-ray spectrometry. Only samples which displayed plutonium heterogeneities, i.e. hot particles or concentrations well in excess (at least two orders of magnitude) of those expected from global fallout, were selected for analysis. The analytical results showed that at Thule the mean 240Pu/239Pu atom ratio was 0.033 +/- 0.004 (n = 4), while at Palomares the equivalent ratio appeared to be significantly higher at 0.056 +/- 0.003 (n = 4). Both ratios are indicative of low burn-up plutonium and are consistent with those reported for weapons-grade plutonium. It is noteworthy that the mean 238Pu/239Pu activity ratio in the Thule samples, at 0.0150 +/- 0.0017 (n = 4), was also lower than that measured in the Palomares samples, namely, 0.0275 +/- 0.0012 (n = 4). The 241Pu/239Pu ratios were similarly different. Finally, the data show, in contrast to Palomares, that not all of the samples from the Thule accident site were contaminated with plutonium of identical isotopic composition. PMID:9241884

  4. Fission Mode Influence on Prompt Neutrons and γ-rays Emitted in the Reaction 239Pu(nth,f)

    NASA Astrophysics Data System (ADS)

    Serot, O.; Litaize, O.; Regnier, D.

    Recently, a Monte-Carlo code, which simulates the fission fragment de-excitation process, has been developed at CEA- Cadarache. Our aim is to get a tool capable to predict spectra and multiplicities of prompt particles (neutron and gamma) and to investigate possible correlations between fission observables. One of the main challenges is to define properly the share of the available excitation energy at scission between the two nascent fission fragments. Initially, after the full acceleration of the fission fragments, these excitation energies were treated within a Fermi-gas approximation in aT2 (where a and T stand for the level density parameter and the nuclear temperature) and a mass dependent law of the temperature ratio (RT=TL/TH, with TL and TH the temperature of the light and heavy fragment) has been proposed. With this RT-law, the main fission observables of the 252Cf(sf) could be reproduced. Here, in order to take into account the fission modes by which the fissioning nucleus undergoes to fission, we have adopted a specific RT-law for each fission mode. For actinides, the main fission modes are called Standard I, Standard II and Super Long (following Brosa's terminology). This new procedure has been applied in the case of the thermal neutron induced fission of 239Pu, reaction for which fission modes are rather well known.

  5. Relative effectiveness of {sup 239}Pu and some other internal emitters for bone cancer induction in beagles

    SciTech Connect

    Lloyd, R.D.; Miller, S.C.; Taylor, G.N.; Bruenger, F.W.; Jee, W.S.S.; Angus, W.

    1994-10-01

    The toxicity ratio (relative effectiveness per gray of average skeletal dose) has been estimated for bone cancer induction in beagles injected as young adults with a number of bone-seeking internal emitters. These experiments yielded calculated toxicity ratios ({+-} SD) relative to {sup 226}Ra = 1.0 of {sup 239}Pu = 16 {+-} 5 (single exposure to monomeric Pu) and 32 {+-} 10 (continuous exposure from an extraskeletal deposit in the body), {sup 224}Ra = 16 {+-} 5 (chronic exposure) and approximately 6 {+-} 2 (single exposure), {sup 228}Th = 8.5 {+-} 2.3, {sup 241}Am = 6 {+-} 0.8, {sup 228}Ra = 2.0 {+-} 0.5, {sup 249}Cf = 6 {+-} 3, {sup 252}Cf = 4 {+-}2, {sup 90}Sr = 1.0 {+-} 0.5 (for high doses) and 0.05 {+-} 0.03 (for low doses) and 0.01 {+-} 0.01 (for extremely low doses). Because no skeletal malignancies were observed among beagles given only {sup 253}Es, the toxicity ratio is undefined. 43 refs., 2 tabs.

  6. Neutron-induced transmutation reactions in 237Np, 238Pu, and 239Pu at the massive natural uranium spallation target

    NASA Astrophysics Data System (ADS)

    Zavorka, L.; Adam, J.; Baldin, A. A.; Caloun, P.; Chilap, V. V.; Furman, W. I.; Kadykov, M. G.; Khushvaktov, J.; Pronskikh, V. S.; Solnyshkin, A. A.; Sotnikov, V.; Stegailov, V. I.; Suchopar, M.; Tsoupko-Sitnikov, V. M.; Tyutyunnikov, S. I.; Voronko, V.; Vrzalova, J.

    2015-04-01

    Transmutation reactions in the 237Np, 238Pu, and 239Pu samples were investigated in the neutron field generated inside a massive (m = 512 kg) natural uranium spallation target. The uranium target assembly QUINTA was irradiated with the deuteron beams of kinetic energy 2, 4, and 8 GeV provided by the Nuclotron accelerator at the Joint Institute for Nuclear Research (JINR) in Dubna. The neutron-induced transmutation of the actinide samples was measured off-line by implementing methods of gamma-ray spectrometry with HPGe detectors. Results of measurement are expressed in the form of both the individual reaction rates and average fission transmutation rates. For the purpose of validation of radiation transport programs, the experimental results were compared with simulations of neutron production and distribution performed by the MCNPX 2.7 and MARS15 codes employing the INCL4-ABLA physics models and LAQGSM event generator, respectively. In general, a good agreement between the experimental and calculated reaction rates was found in the whole interval of provided beam energies.

  7. The CIELO Collaboration: Neutron Reactions on 1H, 16O, 56Fe, 235,238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Dupont, E.; Bauge, E.; Blokhin, A.; Bouland, O.; Brown, D. A.; Capote, R.; Carlson, A.; Danon, Y.; De Saint Jean, C.; Dunn, M.; Fischer, U.; Forrest, R. A.; Frankle, S. C.; Fukahori, T.; Ge, Z.; Grimes, S. M.; Hale, G. M.; Herman, M.; Ignatyuk, A.; Ishikawa, M.; Iwamoto, N.; Iwamoto, O.; Jandel, M.; Jacqmin, R.; Kawano, T.; Kunieda, S.; Kahler, A.; Kiedrowski, B.; Kodeli, I.; Koning, A. J.; Leal, L.; Lee, Y. O.; Lestone, J. P.; Lubitz, C.; MacInnes, M.; McNabb, D.; McKnight, R.; Moxon, M.; Mughabghab, S.; Noguere, G.; Palmiotti, G.; Plompen, A.; Pritychenko, B.; Pronyaev, V.; Rochman, D.; Romain, P.; Roubtsov, D.; Schillebeeckx, P.; Salvatores, M.; Simakov, S.; Soukhovitskiı˜, E. Sh.; Sublet, J. C.; Talou, P.; Thompson, I.; Trkov, A.; Vogt, R.; van der Marck, S.

    2014-04-01

    CIELO (Collaborative International Evaluated Library Organization) provides a new working paradigm to facilitate evaluated nuclear reaction data advances. It brings together experts from across the international nuclear reaction data community to identify and document discrepancies among existing evaluated data libraries, measured data, and model calculation interpretations, and aims to make progress in reconciling these discrepancies to create more accurate ENDF-formatted files. The focus will initially be on a small number of the highest-priority isotopes, namely 1H, 16O, 56Fe, 235,238U, and 239Pu. This paper identifies discrepancies between various evaluations of the highest priority isotopes, and was commissioned by the OECD's Nuclear Energy Agency WPEC (Working Party on International Nuclear Data Evaluation Co-operation) during a meeting held in May 2012. The evaluated data for these materials in the existing nuclear data libraries - ENDF/B-VII.1, JEFF-3.1, JENDL-4.0, CENDL-3.1, ROSFOND, IRDFF 1.0 - are reviewed, discrepancies are identified, and some integral properties are given. The paper summarizes a program of nuclear science and computational work needed to create the new CIELO nuclear data evaluations.

  8. Effects of combined exposure of F344 rats to inhaled {sup 239}PuO{sub 2} and a chemical carcinogen (NNK)

    SciTech Connect

    Lundgren, D.L.; Belinsky, S.A.; Nikula, K.J.; Griffith, W.C.; Hoover, M.D.

    1994-11-01

    Workers in nuclear weapons facilitates have a significant potential for exposure to chemical carcinogens and to radiation from external sources or from internally deposited radionuclides such as {sup 239}Pu. Although the carcinogenic effects of inhaled {sup 239}Pu and many chemicals have been studied individually, very little information is available on their combined effects. One chemical carcinogen that workers could be exposed to, via tobacco smoke, is the tobacco-specific nitrosamine 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a product of the curing of tobacco and pyrolysis of nicotine in tobacco. NNK causes lung tumors in rats, regardless of the route of administration and to a lesser extent tumors in the liver, nasal passages, and pancreas. The purpose of this study is to characterize the effects of combined exposure of rats to NNK and internally deposited plutonium, as well as to these agents alone.

  9. Comparison of the effects of inhaled {sup 239}PuO{sub 2} and {beta}- emitting radionuclides on the incidence of lung carcinomas in laboratory animals

    SciTech Connect

    Hahn, F.F.; Griffith, W.C.; Boecker, B.B.; Muggenburg, B.A.; Lundgren, D.L.

    1991-12-31

    The health effects of inhaling radioactive particles when the lung is the primary organ irradiated were studied in rats and Beagle dogs. The animals were exposed to aerosols of {sup 239}PuO{sub 2} or fission-product radionuclides in insoluble forms and observed for their life span. Lung carcinomas were the primary late-occuring effect. The incidence rate for lung carcinomas was modeled using a proportional hazard rate model. Linear functions predominated below 5 Gy to the lung. The life-time risk for lung carcinomas per 10{sup 4} Gy for beta emitters was 60 for rats and 65 for dogs, and for {sup 239}PuO{sub 2} it was 1500 for rats and 2300 for dogs.

  10. Second interlaboratory comparison study for the analysis of 239Pu in synthetic urine at the microBq (-100 aCi) level by mass spectrometry

    SciTech Connect

    McCurdy, D; Lin, Z; Inn, K W; Bell III, R; Wagner, S; Efurd, D W; Steiner, R; Duffy, C; Hamilton, T F; Brown, T A; Marchetti, A A

    2005-01-28

    As a follow up to the initial 1998 intercomparison study, a second study was initiated in 2001 as part of the ongoing evaluation of the capabilities of various ultra-sensitive methods to analyze {sup 239}Pu in urine samples. The initial study was sponsored by the Department of Energy, Office of International Health Programs to evaluate and validate new technologies that may supersede the existing fission tract analysis (FTA) method for the analysis of {sup 239}Pu in urine at the {micro}Bq/l level. The ultra-sensitive techniques evaluated in the second study included accelerator mass spectrometry (AMS) by LLNL, thermal ionization mass spectrometry (TIMS) by LANL and FTA by the University of Utah. Only the results for the mass spectrometric methods will be presented. For the second study, the testing levels were approximately 4, 9, 29 and 56 {micro}Bq of {sup 239}Pu per liter of synthetic urine. Each test sample also contained {sup 240}Pu at a {sup 240}Pu/{sup 239}Pu atom ratio of {approx}0.15 and natural uranium at a concentration of 50 {micro}Bq/ml. From the results of the two studies, it can be inferred that the best performance at the {micro}Bq level is more laboratory specific than method specific. The second study demonstrated that LANL-TIMS and LLNL-AMS had essentially the same quantification level for both isotopes. Study results for bias and precision and acceptable performance compared to ANSI N13.30 and ANSI N42.22 have been compiled.

  11. [Quantitative evaluation of 90Sr, 137Cs, 239Pu, 241Am transfer from polluted soil to gastric and intestine juice of cows].

    PubMed

    Chizhevskiĭ, I V

    2001-01-01

    Quantitative parameters of 90Sr, 137Cs, 239Pu and 241Am transfer from solid phase of soil to gastric, intestine juice of cows as well as to imitating solutions have been estimated on the base of results of laboratory incubation experiments. A prevailing role of enzyme complex and microflora of gastrointestinal tract in radionuclides transfer from solid phase of soil to solution has been shown. PMID:11605246

  12. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    SciTech Connect

    Haight, Robert C; Devlin, Matthew J; Nelson, Ronald O; O' Donnell, John M; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Belier, Gilbert; Laurent, Benoit; Noda, Shusaku

    2010-01-01

    An experimental campaign was started in 2002 in the framework of a collaboration belween CEA-DAM and the Los Alamos National Laboratory to measure the prompt fission neutron spectra (PFNS) for incident neutron energies from 1 to 200 MeV with consistent error uncertainties over the whole energy range. The prompt neutron spectra in {sup 235,238}U(n,f) and {sup 237}Np(n,f) have been already studied successfully. A first attempt to characterize the prompt neutrons emitted during the fission of the {sup 239}Pu was done in 2007. This contribution will focus on the results obtained during the final experiment to measure the PFNS in {sup 239}Pu(n,f) performed in 2008. Prompt fission neutron spectra in the neutron-induced fission of {sup 239}Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Mean energies obtained from the spectra are discussed and compared to theoretical model calculation.

  13. Long-term changes in mouse lung following inhalation of a fibrosis-inducing dose of 239PuO2: changes in collagen synthesis and degradation rates.

    PubMed

    McAnulty, R J; Moores, S R; Talbot, R J; Bishop, J E; Mays, P K; Laurent, G J

    1991-01-01

    Mice were exposed by nose-only inhalation to 239PuO2, which resulted in an IAD of 1110 +/- 29 Bq. At various times after exposure, rates of collagen metabolism were measured using validated in vivo methods based on the administration of radiolabelled proline, together with a large flooding dose of unlabelled proline and measurement of its incorporation into lung collagen as hydroxyproline. Dramatic increases in both synthesis and degradation rates of collagen were observed. At 54 days after exposure the fractional synthesis rates in experimental mice were almost five times those in controls (control: 3.2 +/- 0.6%/day, 239PuO2-exposed: 14.5 +/- 0.4%/day) and by 300 days synthesis rates, although declining, were still more than double the control values. A similar pattern of change was observed for collagen degradation. The combination of changes in synthesis and degradation rates led to a 60% increase in lung collagen content by 300 days (control: 3.05 +/- 0.24 mg/lung, 239PuO2-exposed: 4.88 +/- 0.42 mg/lung). The data suggest that extensive remodelling of the lung connective tissue matrix occurs during development of fibrosis and that, over long periods of time, small imbalances between synthesis and degradation may result in quite large increases in protein content. PMID:1671069

  14. Matrix effects corrections in DDT assay of {sup 239}Pu with the CTEN instrument

    SciTech Connect

    Hollas, C.L.; Arnone, G.; Brunson, G.; Coop, K.

    1997-11-01

    The accuracy of transuranic (TRU) waste assay using the differential die-away technique depends upon significant corrections to compensate for the effects of the matrix material in which the TRU waste is located. We have used a new instrument, the combined thermal/epithermal neutron (CTEN) instrument for the assay of TRU waste, to develop methods to improve the accuracy of these corrections. Neutrons from a pulsed 14-MeV neutron generator are moderated in the walls of the CTEN cavity and induce fission in the TRU material. The prompt neutrons from these fission events are detected in cadmium-wrapped {sup 3}He neutron detectors. We have developed methods of data acquisition and analysis to extract correlation in the neutron signals resulting from fission during active interrogation. This correlation information, in conjunction with the total number of neutrons detected, is used to determine the fraction of fission neutrons transmitted through the matrix material into the {sup 3}He detectors. This determination allows us to cleanly separate the matrix effects into two processes: matrix modification upon the neutron interrogating flux and matrix modification upon the fraction of fission neutrons transmitted to the neutron detectors. Recent results indicate that for some matrix systems, corrections for position dependent effects within the matrix are possible. 7 refs., 7 figs., 1 tab.

  15. Event-by-event study of prompt neutrons from 239Pu(n,f)

    SciTech Connect

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2009-07-23

    Employing a recently developed Monte-Carlo model, we study the fission of {sup 240}Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte-Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies of less than 2 MeV.

  16. Event-by-Event Study of Prompt Neutrons from 239Pu

    SciTech Connect

    Vogt, R; Randrup, J; Pruet, J; Younes, W

    2010-01-15

    Employing a recently developed Monte Carlo model, we study the fission of {sup 240}Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1 MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies of less than 2 MeV.

  17. Fission Product Yields from Fission Spectrum n+ 239Pu for ENDF/B-VII.1

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Kawano, T.; Barr, D. W.; Mac Innes, M. R.; Kahler, A. C.; Graves, T.; Selby, H.; Burns, C. J.; Inkret, W. C.; Keksis, A. L.; Lestone, J. P.; Sierk, A. J.; Talou, P.

    2010-12-01

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small — especially for 99Mo — we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for 95Zr, 140Ba, 144Ce), but are larger for 99Mo (4%-relative) and 147Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the 147Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends in the measured data, with a focus on

  18. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

  19. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    NASA Astrophysics Data System (ADS)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  20. Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n,f)

    SciTech Connect

    Vogt, R; Randrup, J; Brown, D A; Descalle, M A; Ormand, W E

    2011-11-28

    We have developed an improved evaluation method for the spectrum of neutrons emitted in fission of {sup 239}Pu induced by incident neutrons with energies up to 20 MeV. The covariance data, including incident energy correlations introduced by the evaluation method, were used to fix the input parameters in our event-by-event model of fission, FREYA, by applying formal statistical methods. Formal estimates of uncertainties in the evaluation were developed by randomly sampling model inputs and calculating likelihood functions based on agreement with the evaluated . Our approach is able to employ a greater variety of fission measurements than the relatively coarse spectral data alone. It also allows the study of numerous fission observables for more accurate model validation. The combination of an event-by-event Monte Carlo fission model with a statistical-likelihood analysis is thus a powerful tool for evaluation of fission-neutron data. Our empirical model FREYA follows the complete fission event from birth of the excited fragments through their decay via neutron emission until the fragment excitation energy is below the neutron separation energy when neutron emission can no longer occur. The most recent version of FREYA incorporates pre-equilibrium neutron emission, the emission of the first neutron before equilibrium is reached in the compound nucleus, and multi-chance fission, neutron evaporation prior to fission when the incident neutron energy is above the neutron separation energy. Energy, momentum, charge and mass number are conserved throughout the fission process. The best available values of fragment masses and total kinetic energies are used as inputs to FREYA. We fit three parameters that are not well under control from previous measurements: the shift in the total fragment kinetic energy; the energy scale of the asymptotic level density parameter, controlling the fragment 'temperature' for neutron evaporation; and the relative excitation of the

  1. Product yields of sup 235 U, sup 238 U, sup 237 Np, and sup 239 Pu by photofission reactions with 20-, 30-, and 60-MeV Bremsstrahlung

    SciTech Connect

    Kase, T.; Yamadera, A.; Nakamura, T. ); Shibata, S. ); Fujiwara, I. )

    1992-08-01

    This paper reports that as a basic study of photonuclear transmutation of actinides in high-level radioactive wastes using electron-produced bremsstrahlung, the absolute yields of cumulative mass distributions and the transmutation rate of {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu by photofission reactions induced by 20-, 30-, and 60-MeV bremsstrahlung were measured. The results of mass yield distributions and transmutation yields agree well with other experimental results and those calculated using photofission cross sections, respectively. The transmutation efficiency per electron increases about one order of magnitude with electron energy from 20 to 60 MeV.

  2. Report on the effectiveness of flocculation for removal of {sup 239}Pu at concentrations of 1 pCi/L and 0.1 pCi/L. RFP Pond Water Characterization and Treatment (LATO-EG&G-91-022): Task C deliverables: 5.1.2 and 5.2.2

    SciTech Connect

    Triay, I.R.; Bayhurst, G.K.; Mitchell, A.J.; Cisneros, M.R.; Efurd, D.W.; Roensch, F.R.; Rokop, D.J.; Aguilar, R.D.; Attrep, M.; Nuttall, H.E.

    1993-08-01

    The objective of this work is to assess the effectiveness of flocculation for the removal of Pu from Rocky Flats Plant (RFP) pond waters spiked with {sup 239}Pu at the 1.0 and 0.1 pCi/L level. The flocculation treatment procedure is described in detail. Results are presented for treatment studies for the removal of Pu from C-2 pond water spiked with {sup 239}Pu and from distilled water spiked with {sup 239}Pu.

  3. Relative radiosensitivity of bone tumor induction among beagles as a function of age at injection of {sup 239}Pu or {sup 226}Ra

    SciTech Connect

    Lloyd, R.D.; Taylor, G.N.; Jee, W.S.S.; Miller, S.C.

    1999-01-01

    A comparison was made of the response to induction of skeletal malignancy from exposure of beagles to monomeric {sup 239}Pu or to {sup 226}Ra as juveniles (3 mo of age), young adults (1.5 y of age), or mature adults (5 y of age). This indicated that of these age groups, animals injected as young adults are most sensitive per Gy of average skeletal dose evaluated at 1 y before death. Dogs exposed either as juveniles or as mature adults appeared to be less sensitive. Relative radiosensitivities (RRS) of juvenile and mature beagles ranged between about 0.3 and 0.7 that of dogs injected as young adults. Mean values of RRS for both radionuclides were about 0.5, but RRS values derived from dogs given monomeric {sup 239}Pu appeared to be most reliable and were 0.27 {+-} 0.09 for dogs injected as juveniles and 0.41 {+-} 0.13 for animals exposed as mature adults.

  4. A study of 239Pu production rate in a water cooled natural uranium blanket mock-up of a fusion-fission hybrid reactor

    NASA Astrophysics Data System (ADS)

    Feng, Song; Liu, Rong; Lu, Xinxin; Yang, Yiwei; Xu, Kun; Wang, Mei; Zhu, Tonghua; Jiang, Li; Qin, Jianguo; Jiang, Jieqiong; Han, Zijie; Lai, Caifeng; Wen, Zhongwei

    2016-03-01

    The 239Pu production rate is important data in neutronics design for a natural uranium blanket of a fusion-fission hybrid reactor, and the accuracy and reliability should be validated by integral experiments. The distribution of 239Pu production rates in a subcritical natural uranium blanket mock-up was obtained for the first time with a D-T neutron generator by using an activation technique. Natural uranium foils were placed in different spatial locations of the mock-up, the counts of 277.6 keV γ-rays emitted from 239Np generated by 238U capture reaction were measured by an HPGe γ spectrometer, and the self-absorption of natural uranium foils was corrected. The experiment was analyzed using the Super Monte Carlo neutron transport code SuperMC2.0 with recent nuclear data of 238U from the ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0u2, JEFF-3.2 and CENDL-3.1 libraries. Calculation results with the JEFF-3.2 library agree with the experimental ones best, and they agree within the experimental uncertainty in general with the average ratios of calculation results to experimental results (C/E) in the range of 0.93 to 1.01.

  5. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy

    DOE PAGESBeta

    Hoover, Andrew S.; Bond, Evelyn M.; Croce, Mark P.; Holesinger, Terry G.; Kunde, Gerd J.; Rabin, Michael W.; Wolfsberg, Laura E.; Bennett, Douglas A.; Hays-Wehle, James P.; Schmidt, Dan R.; et al

    2015-02-27

    In this study, we have developed a new category of sensor for measurement of the 240Pu/239Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We foundmore » that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the 240Pu/239Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material.« less

  6. The Need for Precise and Well-documented Experimental Data on Prompt Fission Neutron Spectra from Neutron-induced Fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Neudecker, D.; Taddeucci, T. N.; Haight, R. C.; Lee, H. Y.; White, M. C.; Rising, M. E.

    2016-01-01

    The spectrum of neutrons emitted promptly after 239Pu(n,f)-a so-called prompt fission neutron spectrum (PFNS)-is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed with the improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the 239Pu PFNS as a ratio to either the 235U or 252Cf PFNS.

  7. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy.

    PubMed

    Hoover, Andrew S; Bond, Evelyn M; Croce, Mark P; Holesinger, Terry G; Kunde, Gerd J; Rabin, Michael W; Wolfsberg, Laura E; Bennett, Douglas A; Hays-Wehle, James P; Schmidt, Dan R; Swetz, Daniel; Ullom, Joel N

    2015-04-01

    We have developed a new category of sensor for measurement of the (240)Pu/(239)Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We found that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the (240)Pu/(239)Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material. PMID:25723106

  8. The gender-specific chest wall thickness prediction equations for routine measurements of 239Pu and 241Am within the lungs using HPGe detectors.

    PubMed

    Vickers, L R

    1996-03-01

    The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17--60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI "phoswich" detection system, which is not the routine detection system in use; the subject position was supine, which is not the routine position; the equation did not account for the intercostal tissue thicknesses of muscle and adipose which significantly attenuate low energy photons (17--60keV); it was derived from male subjects only and is used to predict the chest wall thickness of female subjects for whom it is not applicable. The current chest wall thickness prediction equation yields unacceptable percent errors in the HPGe detection efficiency calibration for 239Pu and 241Am (17- and 59.5-keV photons, respectively) relative to the gender-specific HPGe chest wall thickness prediction equations of this paper (+284% to --73% for 239Pu; (+)42% to --39% for 241Am). As a result, use of the current chest wall thickness prediction equation yields unacceptable percent errors (proportional in magnitude to the percent errors in the detection efficiency calibration) in the calculation of the minimum detectable activity (Bq) or in an initial assessment of a radioactive contamination exposure detected by a routine lung count measurement. PMID:8609026

  9. The need for precise and well-documented experimental data on prompt fission neutron spectra from neutron-induced fission of 239Pu

    DOE PAGESBeta

    Neudecker, Denise; Taddeucci, Terry Nicholas; Haight, Robert Cameron; Lee, Hye Young; White, Morgan Curtis; Rising, Michael Evans

    2016-01-06

    The spectrum of neutrons emitted promptly after 239Pu(n,f)—a so-called prompt fission neutron spectrum (PFNS)—is a quantity of high interest, for instance, for reactor physics and global security. However, there are only few experimental data sets available that are suitable for evaluations. In addition, some of those data sets differ by more than their 1-σ uncertainty boundaries. We present the results of MCNP studies indicating that these differences are partly caused by underestimated multiple scattering contributions, over-corrected background, and inconsistent deconvolution methods. A detailed uncertainty quantification for suitable experimental data was undertaken including these effects, and test-evaluations were performed with themore » improved uncertainty information. The test-evaluations illustrate that the inadequately estimated effects and detailed uncertainty quantification have an impact on the evaluated PFNS and associated uncertainties as well as the neutron multiplicity of selected critical assemblies. A summary of data and documentation needs to improve the quality of the experimental database is provided based on the results of simulations and test-evaluations. Furthermore, given the possibly substantial distortion of the PFNS by multiple scattering and background effects, special care should be taken to reduce these effects in future measurements, e.g., by measuring the 239Pu PFNS as a ratio to either the 235U or 252Cf PFNS.« less

  10. A comparison of the natural survival of beagle dogs injected intravenously with low levels of 239Pu, 226Ra, 228Ra, 228Th, or 90Sr.

    PubMed

    Bruenger, F W; Miller, S C; Lloyd, R D

    1991-06-01

    The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq 239Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq 226Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq 228Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq 228Th/kg, and 12 dogs injected with 21.13 +/- 1.74 kBq 90Sr/kg was evaluated statistically. The amounts of these radionuclides are related directly to the estimated maximum permissible body burdens for humans suggested in ICRP II (1959). They constitute a level of exposure that initially was assumed to cause no deleterious effects in dogs. This study had two objectives: (1) identification of homogeneous control groups against which to evaluate the survival of the irradiated groups and (2) comparison of the survival characteristics and estimation of mortality or hazard rate ratios for control dogs vs dogs injected with the baseline dosages given above. It was shown, by goodness-of-fit plots, that the Cox proportional hazards model was an appropriate method of analysis. Therefore, covariates that possibly could influence survival were tested for significance. Only the effects of grand mal seizure, which is caused in epileptic dogs by an external stimulus and can be fatal if untreated, were significant (P less than 0.0001). Consequently, in the final model, death from grand mal seizure was considered as accidental. After censoring the dogs dying from grand mal seizure, it was established that the data for the control groups from previous and contemporary experiments could be pooled. The change in hazard rates relative to controls resulting from exposure to the baseline radionuclide level was modest, 1.6 times for 239Pu (P = 0.033), 1.0(4) for 226Ra (P = 0.86), 1.9 for 228Ra (P = 0.035), 2.5 for 228Th (P less than 0.001), and 0.52 for 90Sr (P = 0.041). Bone tumor induction was clearly elevated in dogs injected with 239Pu and 228Th. When the effect of these bone tumors on survival

  11. Comparative studies on the lysosomal association of monomeric /sup 239/Pu and /sup 241/Am in rat and Chinese hamster liver: analysis with sucrose, metrizamide, and Percoll density gradients of subcellular binding as dependent on time

    SciTech Connect

    Suetterlin, U.; Thies, W.G.; Haffner, H.; Seidel, A.

    1984-05-01

    The binding of /sup 239/Pu and /sup 241/Am in the livers of Chinese hamsters and rats was analyzed by centrifugation of a mitochondrial-lysosomal fraction in sucrose, metrizamide, and Percoll density gradients at intervals between 4 and 70 days after nuclide injection. The behavior of /sup 239/Pu and /sup 241/Am during the centrifugation experiments was very similar. In contrast to the results for rats, the median densities of the nuclide fraction liberated by addition of Triton X-100, and the nuclide profiles do not respond typically to Triton WR 1339 treatment of the animals. It was concluded from the results that the major fraction of /sup 239/Pu and /sup 241/Am remained bound to typical lysosomes in rat liver, whereas those in hamster liver may be transformed into telolysosomes. Possibly, a vesicular biliary transport system for certain heavy metals, for which evidence exists in rat liver, does not occur in Chinese hamster liver.

  12. Fission track analysis of plutonium in small specimens of biological material: Ultrasensitive analysis for sup 239 Pu in 50 urine samples from the Marshall Islands furnished by Brookhaven National Laboratory

    SciTech Connect

    Wrenn, M.E.; Singh, N.P.; Xue, Ying-Hua.

    1990-11-20

    A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine. The technique involves means to remove potentially interfering natural uranium from the sample and reagents. The method was applied to 50 urine samples including an unknown number of spikes and controls from the Marshall Islands. 49 samples were successfully analyzed. The mean activity for the 47 samples which were not positive for {sup 239}Pu did not differ significantly from the mean for our control samples, which consisted of urines collected from six young adult Utah residents. 2 figs., 12 tabs.

  13. A method of measurement of (239)Pu, (240)Pu, (241)Pu in high U content marine sediments by sector field ICP-MS and its application to Fukushima sediment samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tazoe, Hirofumi; Tagami, Keiko; Uchida, Shigeo; Yamada, Masatoshi

    2014-01-01

    An accurate and precise analytical method is highly needed for the determination of Pu isotopes in marine sediments for the long-term marine environment monitoring that is being done since the Fukushima Dai-ichi Nuclear Power Plant accident. The elimination of uranium from the sediment samples needs to be carefully checked. We established an analytical method based on anion-exchange chromatography and SF-ICP-MS in this work. A uranium decontamination factor of 2 × 10(6) was achieved, and the U concentrations in the final sample solutions were typically below 4 pg mL(-1), thus no extra correction of (238)U interferences from the Pu spectra was needed. The method was suitable for the analysis of (241)Pu in marine sediments using large sample amounts (>10 g). We validated the method by measuring marine sediment reference materials and our results agreed well with the certified and the literature values. Surface sediments and one sediment core sample collected after the nuclear accident were analyzed. The characterization of (241)Pu/(239)Pu atom ratios in the surface sediments and the vertical distribution of Pu isotopes showed that there was no detectable Pu contamination from the nuclear accident in the marine sediments collected 30 km off the plant site. PMID:24328266

  14. Estimating Reaction Cross Sections from Measured (Gamma)-Ray Yields: The 238U(n,2n) and 239Pu(n,2n) Cross Sections

    SciTech Connect

    Younes, W

    2002-11-18

    A procedure is presented to deduce the reaction-channel cross section from measured partial {gamma}-ray cross sections. In its simplest form, the procedure consists in adding complementary measured and calculated contributions to produce the channel cross section. A matrix formalism is introduced to provide a rigorous framework for this approach. The formalism is illustrated using a fictitious product nucleus with a simple level scheme, and a general algorithm is presented to process any level scheme. In order to circumvent the cumbersome algebra that can arise in the matrix formalism, a more intuitive graphical procedure is introduced to obtain the same reaction cross-section estimate. The features and limitations of the method are discussed, and the technique is applied to extract the {sup 235}U (n,2n) and {sup 239}Pu(n,2n) cross sections from experimental partial {gamma}-ray cross sections, coupled with (enhanced) Hauser-Feshbach calculations.

  15. Radionuclide concentrations in soils and vegetation at Low-Level Radioactive Waste Disposal Area G during the 1998 growing season (with a cumulative summary of {sup 3}H and {sup 239}Pu over time)

    SciTech Connect

    P. R. Fresquez; M. H. Ebinger; R. J. Wechsler; L. Naranjo, Jr.

    1999-11-01

    Soils and unwashed overstory and understory vegetation were collected at eight locations within and around Area G, a disposal facility for low-level, radioactive solid waste at Los Alamos National Laboratory. The samples were analyzed for {sup 3}H, {sup 238}Pu, {sup 239}Pu, {sup 90}Sr, {sup 241}Am, {sup 137}Cs, {sup tot}U. Most of the radionuclide concentrations in soils and vegetation were within the upper 95% level of background concentrations except for {sup 3}H and {sup 239}Pu. Tritium concentrations in vegetation from most sites were greater than background concentrations of about 2 pCi mL{sup {minus}1}. The concentrations of {sup 239}Pu in soils and understory vegetation were largest in samples collected several meters north of the transuranic waste pad area and were consistent with previous results. Based on {sup 3}H and {sup 239}Pu data through 1998, it was shown that concentrations were (1) significantly greater than background concentrations (p < 0.05) in soils and vegetation collected from most locations at Area G, and (2) there was no systematic increase or decrease in concentrations with time apparent in the data.

  16. Beta and gamma decay heat measurements between 0.1s - 50,000s for neturon fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Progress report, June 1, 1992--December 31, 1994

    SciTech Connect

    Schier, W.A.; Couchell, G.P.

    1997-05-01

    In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining gamma-ray intensities of individual fission products to deduce fission-product yields. Spectral decomposition and analysis codes were developed for deducing energy distributions from measured aggregate beta and gamma spectra. The aggregate measurements in the time interval 0.2 - 20s after fission are of special importance since in this region data from many short-lived nuclei are missing and summation calculations in this region rely on model calculations for a large fraction of their predicted beta and gamma decay heat energy spectra. Comparison with ENDF/B-VI fission product data was performed in parallel with the measurements through a close collaboration with Dr. T. England at LANL, assisted by one of our graduate students. Such aggregate measurements provide tests of the Gross Theory of beta decay used to calculated missing contributions to this data base. Fission-product yields deduced from the HPGe studies will check the accuracy of the semi-empirical Gaussian dispersion model used presently by evaluators in the absence of measured yields.

  17. The Association of Inbreeding With Lung Fibrosis Incidence in Beagle Dogs That Inhaled 238PuO2 or 239PuO2.

    SciTech Connect

    Wilson, Dulaney A.; Brigantic, Andrea M.; Morgan, William F.

    2011-09-12

    Studies of health effects in animals after exposure to internally deposited radionuclides were intended to supplement observational studies in humans. Both nuclear workers and Beagle dogs have exhibited plutonium associated lung fibrosis; however, the dogs smaller gene pool may limit the applicability of findings to humans. Data on Beagles that inhaled either plutonium-238 dioxide (238PuO2) or plutonium-239 dioxide (239PuO2) were analyzed. Wright's Coefficient of Inbreeding was used to measure genetic or familial susceptibility and was assessed as an explanatory variable when modeling the association between lung fibrosis incidence and plutonium exposure. Lung fibrosis was diagnosed in approximately 80% of the exposed dogs compared with 23.7% of the control dogs. The maximum degree of inbreeding was 9.4%. Regardless of isotope, the addition of inbreeding significantly improved the model in female dogs but not in males. In female dogs an increased inbreeding coefficient predicted decreased hazard of a lung fibrosis diagnosis. Lung fibrosis was common in these dogs with inbreeding affecting models of lung fibrosis incidence in females but not in males. The apparent protective effect in females predicted by these models of lung fibrosis incidence is likely to be minimal given the small degree of inbreeding in these groups.

  18. Improved evaluation of [sup 239]Pu (n,f) between 0.1 and 20 MeV incident neutrons energies

    SciTech Connect

    Talou, P.; Young, P. G. ,; Chadwick, M. B.

    2001-01-01

    Accurate cross sections lie at the heart of successful neutronics simulations. The advent of innovative nuclear designs such as Accelerator Driven Systems (ADS) have recently emphasized the need for accurate measurements, evaluations, and calculations of neutron-induced fission cross sections over a wide range of nuclei and energies. As a first step, we have performed a thorough covariance analysis of the neutron induced fission cross section of {sup 239}Pu between 0.1 and 20 MeV. The choice of this first study has been driven by the importcame of this Pu isotope in the US nuclear waste stream. Newly available experimental data (both absolute and in ratio to the standard {sup 235}U) have been included in this new evaluation. A Bayesian statistical approach has been used to infer posterior knowledge on the cross sections and on the associated errors (standard deviations + correlations). Significant reductions of these errors are observed, compared to the previous ENDF/B-VI evaluation. Large changes (up to 4% in places) appear above 14 MeV incident neutron energies, mainly due to a recent revised {sup 235}U (n,f) evaluation. Overall very good agreement is observed elsewhere. Finally, a comparison between this new evaluation and other existing evaluations is discussed.

  19. Investigations of the Space Parity Violation and Interference Effects in the Fragment Angular Distributions of 235U, 233U, and 239Pu Fission by Resonance Neutrons

    NASA Astrophysics Data System (ADS)

    Sokolov, V. E.; Gagarski, A. M.; Guseva, I. S.; Golosovskaya, S. P.; Krasnoshchokova, I. S.; Petrov, G. A.; Petrova, V. I.; Petukhov, A. K.; Pleva, Yu. S.; Alfimenkov, V. P.; Chernikov, A. N.; Lason, L.; Mareev, Yu. D.; Novitski, V. V.; Pikelner, L. B.; Pikelner, T. L.; Tsulaya, M. I.

    2005-05-01

    Investigations of the space parity nonconserving (PNC) asymmetry of 233U, 235U, and 239Pu fission fragment emission and parity conserving (PC) interference effects of left-right and forward-backward asymmetries were carried out on the neutron beams of the reactor IBR-30 (JINR, Dubna) over the range of neutron energies from 0.02 eV to about 100 eV. All experimental results obtained have been found to be in a good mutual accordance within the frames of modern theoretical conceptions about the mechanisms of PNC and PC effects forming in fission process induced by slow neutrons. In case of the P-even interference effects of asymmetry the evident mutual well-marked irregularities in their neutron energy dependencies up to about 100 eV were observed. It is connected with the interference of s, p-resonances at fission compound stage according to modern theory. As a remarkable result of the PNC effect measurements the resonance behavior of the PNC asymmetry coefficients in the low neutron energy region (En < 2 eV) was observed. Unfortunately, the statistical accuracy of the PNC effect measurements is not enough for observation of these resonance effects in other cases of more high energies. Results of simultaneous analysis of all three asymmetry effects for all three nuclei are presented. The satisfactory combined description of the experimental points is received. As a result of theoretical evaluation of these data main parameters and the estimates of nuclear matrix elements of the weak interaction for some p-resonances in the low energy range were extracted.

  20. Fission Product Yields from Fission Spectrum n+{sup 239}Pu for ENDF/B-VII.1

    SciTech Connect

    Chadwick, M.B.; Kawano, T.; Barr, D.W.; Mac Innes, M.R.; Kahler, A.C.; Graves, T.; Selby, H.; Burns, C.J.; Inkret, W.C.; Keksis, A.L.; Lestone, J.P.; Sierk, A.J.; Talou, P.

    2010-12-15

    We describe a new cumulated fission product yield (FPY) evaluation for fission spectrum neutrons on plutonium that updates the ENDF/B-VI evaluation by England and Rider, for the forthcoming ENDF/B-VII.1 database release. We focus on FPs that are needed for high accuracy burnup assessments; that is, for inferring the number of fissions in a neutron environment. Los Alamos conducted an experiment in the 1970s in the Bigten fast critical assembly to determine fission product yields as part of the Interlaboratory Reaction Rate (ILRR) collaboration, and this has defined the Laboratory's fission standard to this day. Our evaluation includes use of the LANL-ILRR measurements (not previously available to evaluators) as well as other Laboratory FPY measurements published in the literature, especially the high-accuracy mass spectrometry data from Maeck and others. Because the measurement database for some of the FPs is small - especially for {sup 99}Mo - we use a meta-analysis that incorporates insights from other accurately-measured benchmark FP data, using R-value ratio measurements. The meta-analysis supports the FP measurements from the LANL-ILRR experiment. Differences between our new evaluations and ENDF/B-VI are small for some FPs (less than 1-2%-relative for {sup 95}Zr, {sup 140}Ba, {sup 144}Ce), but are larger for {sup 99}Mo (4%-relative) and {sup 147}Nd (5%-relative, at 1.5 MeV) respectively. We present evidence for an incident neutron energy dependence to the {sup 147}Nd fission product yield that accounts for observed differences in the FPY at a few-hundred keV average energy in fast reactors versus measurements made at higher average neutron energies in Los Alamos' fast critical assemblies. Accounting for such FPY neutron energy dependencies is important if one wants to reach a goal of determining the number of fissions to accuracies of 1-2%. An evaluation of the energy-dependence of fission product yields is given for all A values based on systematical trends

  1. Transuranic concentrations in reef and pelagic fish from the Marshall Islands. [/sup 239/Pu, /sup 240/Pu

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.

    1980-09-01

    Concentrations of /sup 239 + 240/Pu are reported in tissues of several species of reef and pelagic fish caught at 14 different atolls in the northern Marshall Islands. Several regularities that are species dependent are evident in the distribution of /sup 239 + 240/Pu among different body tissues. Concentrations in liver always exceeded those in bone and concentrations were lowest in the muscle of all fish analyzed. A progressive discrimination against /sup 239 + 240/Pu was observed at successive trophic levels at all atolls except Bikini and Enewetak, where it was difficult to conclude if any real difference exists between the average concentration factor for /sup 239 + 240/Pu among all fish, which include bottom feeding and grazing herbivores, bottom feeding carnivores, and pelagic carnivores from different atoll locations. The average concentration of /sup 239 + 240/Pu in the muscle of surgeonfish from Bikini and Enewetak was not significantly different from the average concentrations determined in these fish at the other, lesser contaminated atolls. Concentrations among all 3rd, 4th, and 5th trophic level species are highest at Bikini where higher environmental concentrations are found. The reasons for the anomalously low concentrations in herbivores from Bikini and Enewetak are not known.

  2. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; Kelley, J. H.; Krishichayan; Macri, R.; Rusev, G.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2016-01-01

    Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varying degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission chamber and gamma

  3. Energy dependence of fission product yields from 235U, 238U and 239Pu for incident neutron energies between 0.5 and 14.8 MeV

    DOE PAGESBeta

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; et al

    2016-01-06

    In this study, Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varyingmore » degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual

  4. Study on Prompt Fission Neutron Spectra and Associated Covariances for 235U(nth,f) and 239Pu(nth,f)

    NASA Astrophysics Data System (ADS)

    Berge, L.; Litaize, O.; Serot, O.; Jean, C. De Saint; Archier, P.; Peneliau, Y.

    normalization of experimental spectra, and the uncertainty on the energy-dependent neutron detection efficiency. We show the resulting PFNS and associated covariance matrix in the case of thermal neutron-induced fission of 235U and 239Pu.

  5. Influences of parameter uncertainties within the ICRP-66 respiratory tract model: regional tissue doses for 239PuO2 and 238UO2/238U3O8.

    PubMed

    Farfán, Eduardo B; Huston, Thomas E; Bolch, W Emmett; Vernetson, William G; Bolch, Wesley E

    2003-04-01

    This paper extends an examination of the influence of parameter uncertainties on regional doses to respiratory tract tissues for short-ranged alpha particles using the ICRP-66 respiratory tract model. Previous papers examined uncertainties in the deposition and clearance aspects of the model. The critical parameters examined in this study included target tissue depths, thicknesses, and masses, particularly within the thoracic or lung regions of the respiratory tract. Probability density functions were assigned for the parameters based on published data. The probabilistic computer code LUDUC (Lung Dose Uncertainty Code) was used to assess regional and total lung doses from inhaled aerosols of 239PuO2 and 238UO2/238U3O8. Dose uncertainty was noted to depend on the particle aerodynamic diameter. Additionally, dose distributions were found to follow a lognormal distribution pattern. For 239PuO2 and 238UO2/238U3O8, this study showed that the uncertainty in lung dose increases by factors of approximately 50 and approximately 70 for plutonium and uranium oxides, respectively, over the particle size range from 0.1 to 20 microm. For typical exposure scenarios involving both radionuclides, the ratio of the 95% dose fractile to the 5% dose fractile ranged from approximately 8-10 (corresponding to a geometric standard deviation, or GSD, of about 1.7-2) for particle diameters of 0.1 to 1 microm. This ratio increased to about 370 for plutonium oxide (GSD approximately 4.5) and to about 600 for uranium oxide (GSD approximately 5) as the particle diameter approached 20 microm. However, thoracic tissue doses were quite low at larger particle sizes because most of the deposition occurred in the extrathoracic airways. For 239PuO2, median doses from LUDUC were found be in general agreement with those for Reference Man (via deterministic LUDEP 2.0 calculations) in the particle range of 0.1 to 5 microm. However, median doses to the basal cell nuclei of the bronchial airways (BB

  6. A comparison of the natural survival of beagle dogs injected intravenously with low levels of sup 239 Pu, sup 226 Ra, sup 228 Ra, sup 228 Th, or sup 90 Sr

    SciTech Connect

    Bruenger, F.W.; Miller, S.C.; Lloyd, R.D. )

    1991-06-01

    The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq {sup 239}Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq {sup 226}Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq {sup 228}Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq {sup 228}Th/kg, and 12 dogs injected with 21.13 +/- 1.74 kBq {sup 90}Sr/kg was evaluated statistically. The amounts of these radionuclides are related directly to the estimated maximum permissible body burdens for humans suggested in ICRP II (1959). They constitute a level of exposure that initially was assumed to cause no deleterious effects in dogs. This study had two objectives: (1) identification of homogeneous control groups against which to evaluate the survival of the irradiated groups and (2) comparison of the survival characteristics and estimation of mortality or hazard rate ratios for control dogs vs dogs injected with the baseline dosages given above. It was shown, by goodness-of-fit plots, that the Cox proportional hazards model was an appropriate method of analysis. Therefore, covariates that possibly could influence survival were tested for significance. Only the effects of grand mal seizure, which is caused in epileptic dogs by an external stimulus and can be fatal if untreated, were significant (P less than 0.0001). Consequently, in the final model, death from grand mal seizure was considered as accidental. After censoring the dogs dying from grand mal seizure, it was established that the data for the control groups from previous and contemporary experiments could be pooled. The change in hazard rates relative to controls resulting from exposure to the baseline radionuclide level was modest, 1.6 times for {sup 239}Pu (P = 0.033), 1.0(4) for {sup 226}Ra (P = 0.86), 1.9 for {sup 228}Ra (P = 0.035), 2.5 for {sup 228}Th (P less than 0.001), and 0.52 for {sup 90}Sr (P = 0.041).

  7. On the similarity of 239Pu α-activity histograms when the angular velocities of the Earth diurnal rotation, orbital movement and rotation of collimators are equalized

    NASA Astrophysics Data System (ADS)

    Shnoll, S. E.; Rubinstein, I. A.; Shapovalov, S. N.; Tolokonnikova, A. A.; Shlektaryov, V. A.; Kolombet, V. A.; Kondrashova, M. N.

    2016-01-01

    It was shown earlier that the persistent "scatter" of results of measurements of any nature is determined by the diurnal and orbital movement of the Earth. The movement is accompanied by "macroscopic fluctuations" (MF)—regular, periodic changes in the shape of histograms, spectra of fluctuation amplitudes of the measured parameters. There are two near-daily periods ("sidereal", 1436 min; and "solar", 1440 min) and three yearly ones ("calendar", 365 average solar days; "tropical", 365 days 5 h and 48 min; and "sidereal", 365 days 6 h and 9 min). This periodicity was explained by the objects whose parameters are measured passing through the same spatial-temporal heterogeneities as the Earth rotates and shifts along its orbit.

  8. Leaching of UO2 pellets doped with alpha-emitters (238/239Pu) in synthetic deep Callovian-Oxfordian groundwater

    NASA Astrophysics Data System (ADS)

    Tribet, M.; Jégou, C.; Broudic, V.; Marques, C.; Rigaux, P.; Gavazzi, A.

    2010-03-01

    The reactivity of a polycrystalline UO2 surface under alpha irradiation in contact with groundwater is investigated, in the hypothesis of direct disposal of spent fuel in a deep geological repository. Two series of plutonium-doped UO2 samples (specific alpha activity of 18 and 385 MBq·g-1UO2) were leached in a synthetic Callovian-Oxfordian deep groundwater under anoxic conditions (Ar/CO2 3000 ppm, 3.5 bar relative pressure) to assess both the impact of alpha radiolysis of water and the complexing capacity of the groundwater ions on the dissolution of UO2. This study follows a prior one performed in pure and carbonated waters. Firstly, technical developments were necessary for the analyses in the groundwater solution because of its high salt concentrations: quantification limits were determined for the measurement of uranium and radiolytic H2O2 traces in this medium. Secondly, given the very high reactivity of these samples in the presence of air and in order to minimize any prior surface oxidation, a strict experimental protocol was followed, based on high-temperature annealing in Ar + 4% H2 with preleaching cycles. Each type of UO2 pellet was then leached under static conditions for 30 days (anoxic conditions, deep groundwater solutions). Results on the evolution of uranium releases are presented. For the lowest alpha activity (18 MBq·g-1UO2), uranium releases in groundwater were below the quantification limit of 2 × 10-8 mol·L-1 with a kinetic phosphorescence analyzer, even after 30 days. However, for higher alpha activity (385 MBq·g-1UO2) the uranium releases begin to exceed the quantification limit after 14 days of leaching and then increase exponentially. This increase is comparable to results previously obtained in carbonated solutions.

  9. Application of ICP-QMS for the determination of plutonium in environmental samples for safeguards purposes.

    PubMed

    Godoy, Maria Luiza D P; Godoy, José Marcus; Roldão, Luiz Alfredo

    2007-01-01

    Aiming to determine the plutonium amount as well as its isotopic composition, in particular, in swipe samples for safeguards purposes, an analytical method was developed with a plutonium separation step based on extraction chromatography using 2 cm TEVA columns and detection with quadrupole ICP-MS applying an ultra-sonic nebulizer coupled with membrane desolvation system. The method was successfully applied to New Brunswick plutonium certified reference materials as well as to Lawrence Livermore National Laboratory round robin samples, based on the round robin samples provided by the Institute for Reference Materials and Measurements (Belgium), as part of the Regular European Interlaboratory Measurement Evaluation Programme (REIMEP), campaign 16 (isotopic abundances of plutonium in plutonium nitrate samples), with a total plutonium amount between 1 and 0.25 ng per sample. After the introduction of an additional separation step, it was also possible to carry out precise and accurate total plutonium, (240)Pu/(239)Pu, (241)Pu/(239)Pu and (242)Pu/(239)Pu atom ratios determination in sediment sample showing its applicability to environmental samples in general, reaching a detection limit equivalent to 5 mBq(239)Pu kg(-1). PMID:17543430

  10. Determination of 90Sr and Pu isotopes in contaminated groundwater samples by inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Zoriy, Miroslav V.; Ostapczuk, Peter; Halicz, Ludwik; Hille, Ralf; Becker, J. Sabine

    2005-04-01

    A sensitive analytical method for determining the artificial radionuclides 90Sr, 239Pu and 240Pu at the ultratrace level in groundwater samples from the Semipalatinsk Test Site area in Kazakhstan by double-focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS) was developed. In order to avoid possible isobaric interferences at m/z 90 for 90Sr determination (e.g. 90Zr+, 40Ar50Cr+, 36Ar54Fe+, 58Ni16O2+, 180Hf2+, etc.), the measurements were performed at medium mass resolution under cold plasma conditions. Pu was separated from uranium by means of extraction chromatography using Eichrom TEVA resin with a recovery of 83%. The limits of detection for 90Sr, 239Pu and 240Pu in water samples were determined as 11, 0.12 and 0.1 fg ml-1, respectively. Concentrations of 90Sr and 239Pu in contaminated groundwater samples ranged from 18 to 32 and from 28 to 856 fg ml-1, respectively. The 240Pu/239Pu isotopic ratio in groundwater samples was measured as 0.17. This isotope ratio indicates that the most probable source of contamination of the investigated groundwater samples was the nuclear weapons tests at the Semipalatinsk Test Site conducted by the USSR in the 1960s.

  11. Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.

    PubMed

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo; Tazoe, Hirofumi; Yamada, Masatoshi

    2014-04-11

    Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident. PMID:24636561

  12. Age determination of single plutonium particles after chemical separation

    NASA Astrophysics Data System (ADS)

    Shinonaga, T.; Donohue, D.; Ciurapinski, A.; Klose, D.

    2009-01-01

    Age determination of single plutonium particles was demonstrated using five particles of the standard reference material, NBS 947 (Plutonium Isotopic Standard. National Bureau of Standards, Washington, D.C. 20234, August 19, 1982, currently distributed as NBL CRM-137) and the radioactive decay of 241Pu into 241Am. The elemental ratio of Am/Pu in Pu particles found on a carbon planchet was measured by wavelength dispersive X-ray spectrometry (WDX) coupled to a scanning electron microscope (SEM). After the WDX measurement, each plutonium particle, with an average size of a few μm, was picked up and relocated to a silicon wafer inside the SEM chamber using a micromanipulator. The silicon wafer was then transferred to a quartz tube for dissolution in an acid solution prior to chemical separation. After the Pu was chemically separated from Am and U, the isotopic ratios of Pu ( 240Pu/ 239Pu, 241Pu/ 239Pu and 242Pu/ 239Pu) were measured with a thermal ionization mass spectrometer (TIMS) for the calculation of Pu age. The age of particles determined in this study was in good agreement with the expected age (35.9 a) of NBS 947 within the measurement uncertainty.

  13. Determination of plutonium and other transuranic elements by inductively coupled plasma mass spectrometry: A historical perspective and new frontiers in the environmental sciences

    NASA Astrophysics Data System (ADS)

    Ketterer, Michael E.; Szechenyi, Scott C.

    2008-07-01

    Inductively coupled plasma mass spectrometry (ICPMS), particularly with sector field mass analyzers (SF-ICPMS), has emerged in the past several years as an excellent analytical technique for rapid, highly sensitive determination of transuranic elements (TRU) in environmental samples. SF-ICPMS has advantages of simplicity of sample preparation, high sample throughput, widespread availability in laboratories worldwide, and relatively straightforward operation when compared to other competing mass spectrometric techniques. Arguably, SF-ICPMS is the preferred technique for routine, high-throughput determination of 237Np and the Pu isotopes, excepting 238Pu, at fg-pg levels in environmental samples. Many research groups have now demonstrated the SF-ICPMS determination of 239 + 240 Pu activities, 240Pu/ 239Pu and other Pu atom ratios in several different application areas. Many studies have examined the relative contribution of global fallout vs. local/regional Pu sources in the environment through measurement of 240Pu/ 239Pu and, in some cases, 241Pu/ 239Pu and 242Pu/ 239Pu. "Stratospheric fallout", which was deposited from thermonuclear tests, conducted largely during the 1952-1964 time period, is characterized by a well-defined 240Pu/ 239Pu of ~ 0.18, while most other sources have different ratios. Examples of local/regional Pu sources are the Nevada Test Site, the Chernobyl plume, and accidents at Palomares, Spain and Thule, Greenland. The determination of Pu activities and atom ratios has stimulated much interest in the use of Pu as a marine tracer; several studies have shown that Pu is transported over long distances by ocean currents. 240Pu/ 239Pu ratios > 0.20 in sediments and seawater of the North Pacific are ascribed to ocean current transport of fallout from the Pacific Proving Ground. In nuclear forensics, much effort is focused on detection and fingerprinting of small amounts of TRU in environmental samples consisting of bulk material or individual isolated

  14. Determination of long-lived actinides in soil leachates by inductively coupled plasma: Mass spectrometry

    SciTech Connect

    Crain, J.S.; Smith, L.L.; Yaeger, J.S.; Alvarado, J.A.

    1994-06-01

    Inductively coupled plasma -- mass spectrometry (ICP-MS) was used to concurrently determine multiple long-lived (t{sub 1/2} > 10{sup 4} y) actinide isotopes in soil samples. Ultrasonic nebulization was found to maximize instrument sensitivity. Instrument detection limits for actinides in solution ranged from 50 mBq L{sup {minus}1} ({sup 239}Pu) to 2 {mu}Bq L{sup {minus}1} ({sup 235}U) Hydride adducts of {sup 232}Th and {sup 238}U interfered with the determinations of {sup 233}U and {sup 239} Pu; thus, extraction chromatography was, used to eliminate the sample matrix, concentrate the analytes, and separate uranium from the other actinides. Alpha spectrometric determinations of {sup 230}Th, {sup 239}Pu, and the {sup 234}U/{sup 238}U activity ratio in soil leachates compared well with ICP-MS determinations; however, there were some small systematic differences (ca. 10%) between ICP-MS and a-spectrometric determinations of {sup 234}U and {sup 238}U activities.

  15. Toxicological versus Radiological Hazards of {sup 239}Pu

    SciTech Connect

    Tansky, R.R.

    2001-07-26

    Plutonium is frequently referred to as ''the most toxic substance known to man''. While there are other chemicals that cause more immediately serious health consequences, plutonium does have the lowest permissible levels for any of the radioactive elements. Concentration limits for plutonium and its compounds are based on its radiotoxicity, specifically carcinogenicity, not on its chemical toxicity.

  16. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method. PMID:23952680

  17. An investigation into the effects of quality improvement method on patients' satisfaction: a semi experimental research in Iran.

    PubMed

    Navipour, Hasan; Nayeri, Nahid Dehghan; Hooshmand, Abbas; Zargar, Marjaneh Taghavi

    2011-01-01

    Today, to increase effectiveness is a Strategy for success of organizations and their viability. In health care organization not only service cost- effectiveness is a major problem for productivity and organizational management but also customer-centred is in first priority. Because of these reasons, most of health organization trend to patient satisfaction for their viability. If complex process implemented for viability without attention to patient satisfaction, this is no success result. The FOCUS PDCA process is a new strategy for effectiveness of service quality. To this reason, the recent research done and its objective is to assess effect of FOCUS PDCA process strategy on patient satisfaction in surgery units of hospitals affiliated to Tehran Medical University. This research is a semi experimental with non- equivalent design. The sample was all of patients who hospitalized in two selected surgery units. Self-report was method of data gathering. Patient satisfaction assessed with questionnaire in pre and posttest. Then manipulation implemented as post-operation care process selected. Modelling and opportunity statement Diagrams prepared and improvement team organized. Flow process, convergences and cause- effect charts used to prepare list of items to be improved. Executive program was written. This include personnel training, standard implementation, election and training of quality control nurses (Q.C Ns), daily QC of caring and providing appropriate feed back to personnel, forming group session for determining corrective actions. Then after 1 month patient satisfaction was assessed. Statistical analysis shows this process increase patient satisfaction and it leads to care effectiveness. The findings of the pre-intervention phase indicated that the satisfaction level had been low in both groups and it is not significantly different in the two groups (P> 0.05). There was a significant difference before and after following intervention in the case study

  18. Analytical method for the determination of Np and Pu in sea water by AMS with respect to the Fukushima accident

    NASA Astrophysics Data System (ADS)

    Hain, K.; Faestermann, T.; Famulok, N.; Fimiani, L.; Gómez-Guzmán, J. M.; Korschinek, G.; Kortmann, F.; Lierse v. Gostomski, Ch.; Ludwig, P.; Shinonaga, T.

    2015-10-01

    A chemical separation procedure for plutonium (Pu) and neptunium (Np) was developed using extraction chromatography, mass spectrometry and radiometric analysis to determine their concentrations and isotopic ratios in sea water. 241Am, which causes isobaric background to 241Pu in mass spectrometric measurements, was successfully separated from the Pu fraction by this method. Water samples which were spiked with 242Pu and 237Np or 239Np, respectively, were used for chemical yield determination. The chemical yields of Pu and Np, which were determined by alpha and gamma spectrometry at the Radiochemie München (RCM), of more than 85% were obtained. The developed method was applied to analyze the concentration of Pu and Np in the certified reference material, IAEA-443, by Accelerator Mass Spectrometry (AMS) at the Maier-Leibnitz-Laboratory (MLL) to check the applicability of the method to sea water samples. The concentrations of 240Pu, 241Pu and 237Np obtained in this study are in agreement with the certified and literature values within the uncertainties. Due to strong isotopic interference of 239Pu with 238U, it was not possible to analyze the concentration of 239Pu. Some modifications of the chemical separation method to suppress the uranium (U) fraction are under consideration. This method can be used for the analysis of Pu and Np in Pacific Ocean water samples collected after the Fukushima accident.

  19. Determination of 237Np and Pu isotopes in large soil samples by inductively coupled plasma mass spectrometry.

    PubMed

    Maxwell, Sherrod L; Culligan, Brian K; Jones, Vernon D; Nichols, Sheldon T; Bernard, Maureen A; Noyes, Gary W

    2010-12-01

    A new method for the determination of (237)Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of (237)Np and Pu isotopes by ICP-MS. (238)U can interfere with (239)Pu measurement by ICP-MS as (238)UH(+) mass overlap and (237)Np via (238)U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1×10(6). Alpha spectrometry can also be applied so that the shorter-lived (238)Pu isotope can be measured successfully. (239) Pu, (242)Pu and (237)Np were measured by ICP-MS, while (236)Pu and (238)Pu were measured by alpha spectrometry. PMID:21056724

  20. DETERMINATION OF 237NP AND PU ISOTOPES IN LARGE SOIL SAMPLES BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    SciTech Connect

    Maxwell, S.

    2010-07-26

    A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu and {sup 238}Pu were measured by alpha spectrometry.

  1. Determination of actinides in environmental and biological samples using high-performance chelation ion chromatography coupled to sector-field inductively coupled plasma mass spectrometry.

    PubMed

    Truscott, J B; Jones, P; Fairman, B E; Evans, E H

    2001-08-31

    High-performance chelation ion chromatography, using a neutral polystyrene substrate dynamically loaded with 0.1 mM dipicolinic acid, coupled with sector-field inductively coupled plasma mass spectrometry has been successfully used for the separation of the actinides thorium, uranium, americium, neptunium and plutonium. Using this column it was possible to separate the various actinides from each other and from a complex sample matrix. In particular, it was possible to separate plutonium and uranium to facilitate the detection of the former free of spectral interference. The column also exhibited some selectivity for different oxidation states of Np, Pu and U. Two oxidation states each for plutonium and neptunium were found, tentatively identified as Np(V) and Pu(III) eluting at the solvent front, and Np(IV) and Pu(IV) eluting much later. Detection limits were 12, 8, and 4 fg for 237Np, 239Pu, and 241Am, respectively, for a 0.5 ml injection. The system was successfully used for the determination of 239Pu in NIST 4251 Human Lung and 4353 Rocky Flats Soil, with results of 570+/-29 and 2939+/-226 fg g(-1), respectively, compared with a certified range of 227-951 fg g(-1) for the former and a value of 3307+/-248 fg g(-1) for the latter. PMID:11589474

  2. Combining Differential and Integral Experiments on 239PU for Reducing Uncertainties in Nuclear Data Applications

    NASA Astrophysics Data System (ADS)

    Kawano, T.; Hanson, K. M.; Frankle, S. C.; Talou, P.; Chadwick, M. B.; Little, R. C.

    2006-04-01

    We present an approach to uncertainty quantification for nuclear applications, which combines the covariance evaluation of differential cross-sections data and the error propagation from matching a criticality experiment using a neutron transport calculation. We have studied the effect on Pu-239 fission cross sections of using a one-dimensional neutron transport calculation with the PARTISN code. The evaluation of Pu-239 differential cross-section data is combined with a criticality measurement (Jezebel) using a Bayesian method. To perform the uncertainty quantification for such calculations, we generate a set of random samples of cross sections, which is representative of the covariance matrix, and estimate the distribution of calculated quantities, such as criticality. We show that inclusion of the Jezebel data reduces uncertainties in estimating neutron multiplicity.

  3. A method to determine the time since last purification of weapons grade plutonium.

    PubMed

    Keegan, R P; Gehrke, R J

    2003-01-01

    A non-destructive technique to determine the time since last purification of weapons grade plutonium based on the 241Pu decay series has been developed and demonstrated to provide results that are consistent with our historical and process knowledge. This method is based on the use of the Bateman equations and the decay chain 241Pu-->237U & 241Am-->237Np-->233Pa. Secular equilibrium is assumed between the (2.1 x 10(6) year) 237Np and the (27 day) 233Pa. The proposed method is dependent upon the efficiency of the plutonium separation process but makes no assumption about the relative abundance of 241Pu in 239Pu. Even though the technique was developed for weapons grade plutonium, it is expected to apply to almost any material that contains plutonium. PMID:12941503

  4. Determination of Pu in urine at ultratrace level by sector field inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Zoriy, M. V.; Pickhardt, C.; Ostapczuk, P.; Hille, R.; Becker, J. S.

    2004-04-01

    A new analytical procedure has been developed for the determination of Pu in urine at the low ag ml-1 concentration level by double-focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS). One liter of urine doped with 4 pg 242Pu was analyzed after co-precipitation with Ca3(PO4)2 followed by extraction chromatography on TEVA resin in order to enrich the Pu and remove uranium and matrix elements. Figures of merit of ICP-SFMS for the determination of Pu were studied using two nebulizers, PFA-100 and direct injection high-efficiency nebulizer (DIHEN), for solution introduction with uptake rates of 0.58 and 0.06 ml min-1, respectively. The sensitivity for Pu in ICP-SFMS was determined to be 2000 and 1380 MHz ppm-1 for the PFA-100 and DIHEN nebulizers, respectively. Due to the low solution uptake rate of DIHEN the absolute sensitivity was about seven times better and yielded 1380 counts fg-1 in comparison to 207 counts fg-1 measured with the PFA-100 nebulizer. Recovery using 242Pu tracer was about 70%. The limits of detection for 239Pu in 1 l of urine, based on an enrichment factor of 100 for PFA-100 nebulizer and 1000 for DIHEN, were 9×10-18 and 1.02×10-18 g ml-1, respectively. Measurements of 240Pu/239Pu isotopic ratio in synthetically prepared urine standard solution yielded a precision of 1.8 and 1.9% and accuracy of 1.5 and 1.8% for the PFA-100 and DIHEN nebulizers, respectively.

  5. Determination of antineutrino spectra from nuclear reactors

    SciTech Connect

    Huber, Patrick

    2011-08-15

    In this paper we study the effect of well-known higher-order corrections to the allowed {beta}-decay spectrum on the determination of antineutrino spectra resulting from the decays of fission fragments. In particular, we try to estimate the associated theory errors and find that induced currents like weak magnetism may ultimately limit our ability to improve the current accuracy and under certain circumstance could even greatly increase the theoretical errors. We also perform a critical evaluation of the errors associated with our method to extract the antineutrino spectrum using synthetic {beta} spectra. It turns out that a fit using only virtual {beta} branches with a judicious choice of the effective nuclear charge provides results with a minimal bias. We apply this method to actual data for {sup 235}U, {sup 239}Pu, and {sup 241}Pu and confirm, within errors, recent results, which indicate a net 3% upward shift in energy-averaged antineutrino fluxes. However, we also find significant shape differences which can, in principle, be tested by high-statistics antineutrino data samples.

  6. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity

    SciTech Connect

    Jacqmin, R.P.

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J ({ge}K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R ({le}K) orthogonalized modes'' of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  7. A semi-experimental nodal synthesis method for the on-line reconstruction of three-dimensional neutron flux-shapes and reactivity. Final report

    SciTech Connect

    Jacqmin, R.P.

    1991-12-10

    The safety and optimal performance of large, commercial, light-water reactors require the knowledge at all time of the neutron-flux distribution in the core. In principle, this information can be obtained by solving the time-dependent neutron diffusion equations. However, this approach is complicated and very expensive. Sufficiently accurate, real-time calculations (time scale of approximately one second) are not yet possible on desktop computers, even with fast-running, nodal kinetics codes. A semi-experimental, nodal synthesis method which avoids the solution of the time-dependent, neutron diffusion equations is described. The essential idea of this method is to approximate instantaneous nodal group-fluxes by a linear combination of K, precomputed, three-dimensional, static expansion-functions. The time-dependent coefficients of the combination are found from the requirement that the reconstructed flux-distribution agree in a least-squares sense with the readings of J ({ge}K) fixed, prompt-responding neutron-detectors. Possible numerical difficulties with the least-squares solution of the ill-conditioned, J-by-K system of equations are brought under complete control by the use of a singular-value-decomposition technique. This procedure amounts to the rearrangement of the original, linear combination of K expansion functions into an equivalent more convenient, linear combination of R ({le}K) orthogonalized ``modes`` of decreasing magnitude. Exceedingly small modes are zeroed to eliminate any risk of roundoff-error amplification, and to assure consistency with the limited accuracy of the data. Additional modes are zeroed when it is desirable to limit the sensitivity of the results to measurement noise.

  8. Determination of plutonium isotopic composition by gamma-ray spectroscopy

    SciTech Connect

    Sampson, T.E.; Hsue, S.T.; Parker, J.L.; Johnson, S.S.; Bowersox, D.F.

    1981-01-01

    We discuss the general approach, computerized data analysis methods, and results of measurements used to determine the isotopic composition of plutonium by gamma-ray spectroscopy. The simple techniques are designed to be applicable to samples of arbitrary size, geometry, age, chemical, and isotopic composition. The combination of the gamma spectroscopic measurement of isotopic composition coupled with calorimetric measurement of total sample power is shown to give a totally nondestructive determination of sample plutonium mass with a precision of 0.6% for 1000-g samples of PuO/sub 2/ with 12% /sup 240/Pu content. The precision of isotopic measurements depends upon many factors, including sample size, sample geometry, and isotopic content. Typical ranges are found to be /sup 238/Pu, 1 to 10%; /sup 239/Pu, 0.1 to 0.5%; /sup 240/Pu, 2 to 5%; /sup 241/Pu, 0.3 to 0.7%; /sup 242/Pu (determined by isotopic correlation); and /sup 241/Am, 0.2 to 10%.

  9. Method for actinides and Sr-90 determination in urine samples.

    PubMed

    Alvarez, A; Navarro, N

    1996-01-01

    The primary goal of radiation protection in decommissioning and decontamination of the old nuclear facilities of the CIEMAT is to monitor and minimize exposure of personnel. Monitoring programs include determination of actinides and 90Sr in biological samples. A technique for the sequential measurement of low levels of 239Pu, 241Am and 90Sr in urine samples has been developed. The method involves coprecipitation of these radionuclides as phosphates from bulk urine sample. Separation of Plutonium is carried out using a conventional anion exchange technique. Americium and strontium isolations are achieved sequentially by chromatographic extraction (Tru.Spec and Sr.Spec columns) from the load and rinse solutions coming from the anion exchange column. Plutonium and Americium measurements are performed by alpha spectrometry. The mean recovery obtained is 80% and the detection limit for 24 h urine sample (1.41) is 0.6 mBq L-1. 90Sr determination is made by liquid scintillation counting. The detection limit in this case is 1.1 E-01 Bq/L. PMID:8976042

  10. MONTE-CARLO BURNUP CALCULATION UNCERTAINTY QUANTIFICATION AND PROPAGATION DETERMINATION

    SciTech Connect

    Sternat, M.; Nichols, T.

    2011-06-09

    Reactor burnup or depletion codes are used thoroughly in the fields of nuclear forensics and nuclear safeguards. Two common codes include MONTEBURNS and MCNPX/CINDER. These are Monte-Carlo depletion routines utilizing MCNP for neutron transport calculations and either ORIGEN or CINDER for burnup calculations. Uncertainties exist in the MCNP steps, but this information is not passed to the depletion calculations or saved. To quantify this transport uncertainty and determine how it propagates between burnup steps, a statistical analysis of multiple repeated depletion runs is performed. The reactor model chosen is the Oak Ridge Research Reactor (ORR) in a single assembly, infinite lattice configuration. This model was burned for a 150 day cycle broken down into three steps. The output isotopics as well as effective multiplication factor (k-effective) were tabulated and histograms were created at each burnup step using the Scott Method to determine the bin width. The distributions for each code are a statistical benchmark and comparisons made. It was expected that the gram quantities and k-effective histograms would produce normally distributed results since they were produced from a Monte-Carlo routine, but some of the results appear to not. Statistical analyses are performed using the {chi}{sup 2} test against a normal distribution for the k-effective results and several isotopes including {sup 134}Cs, {sup 137}Cs, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 238}Pu, {sup 239}Pu, and {sup 240}Pu.

  11. Plutonium isotopic determination from gamma-ray spectra

    SciTech Connect

    Skourikhine, A.N.; Strittmatter, R.B.; Zardecki, A.

    1998-12-31

    The use of low- and medium-resolution room-temperature detectors for the nondestructive assay of nuclear materials has widespread applications to the safeguarding of nuclear materials. The challenge to using these detectors is the inherent difficulty of the spectral analysis to determine the amount of specific nuclear materials in the measured samples. This is especially true for extracting plutonium isotopic content from low- and medium-resolution spectral lines that are not well resolved. In this paper, neural networks trained by stochastic and singular value decomposition algorithms are applied to retrieve the plutonium isotopic content from a simulated NaI spectra. The simulated sample consists of isotopes {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, {sup 242}Pu, and {sup 241}Am. It is demonstrated that the neutral network optimized by singular value decomposition (SVD) and stochastic training algorithms is capable of estimating plutonium content consistently resulting in an average error much smaller than the error previously reported.

  12. Nondestructive NMR technique for moisture determination in radioactive materials.

    SciTech Connect

    Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

    1998-12-04

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ({sup 3}H, {sup 3}He, {sup 239}Pu, {sup 241}Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO{sub 2} and UO{sub 2} systems. The total moisture was quantified by means of {sup 1}H NMR detection of H{sub 2}O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96.

  13. Spent fuel temperature and age determination from the analysis of uranium and plutonium isotopics

    SciTech Connect

    Scott, Mark R; Eccleston, George W; Bedell, Jeffrey J; Lockard, Chanelle M

    2009-01-01

    The capability to determine the age (time since irradiation) of spent fuel can be useful for verification and safeguards. While the age of spent fuel can be determined based on measurements of short-lived fission products, these measurements are not routinely done nor generally reported. As an alternative, age can also be determined if the uranium (U) and plutonium (Pu) isotopic values are available. Uranium isotopics are not strongly affected by fuel temperature, and bumup is determined from the {sup 235}U and {sup 236}U isotopic values. Age is calculated after estimating the {sup 241}Pu at the end of irradiation while accounting for the fuel temperature, which is determined from {sup 239}Pu or {sup 240}Pu. Burnup and age determinations are calibrated to reactor models that provide uranium and plutonium isotopics over the range of fuel irradiation. The reactor model must contain sufficient fidelity on details of the reactor type, fuel burnup, irradiation history, initial fuel enrichment and fuel temperature to obtain accurate isotopic calculations. If the latter four are unknown, they can be derived from the uranium and plutonium isotopics. Fuel temperature has a significant affect on the production of plutonium isotopics; therefore, one group cross section reactor models, such as ORIGEN, cannot be used for these calculations. Multi-group cross section set codes, such as Oak Ridge National Laboratory's TRITON code, must be used.

  14. Final Report for Nuclear Resonance Fluorescence Measurements of 239Pu above 2.5 MeV

    SciTech Connect

    Johnson, M S; McNabb, D P

    2009-01-07

    Nuclear Resonance Fluorescence measurements were performed at the free electron laser facility at UC Santa Barbara using a bremsstrahlung beam. Three endpoint energies were chosen for the bremsstrahlung to cover as much area above 2.5 MeV as possible. We were able to set an upper limit of NRF state strengths between 2.5 and 3.8 MeV at roughly 38(5) eV barns at the 4-sigma level and 9(2) eV barns at the 1-sigma level. Published results on states near 2.4 MeV indicate strengths about 10(2) eV barns. Details of the results are presented in this report.

  15. Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu

    SciTech Connect

    Beasley, T. M.

    1982-01-01

    The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

  16. Fission fragment charge and mass distributions in 239Pu(n, f ) in the adiabatic nuclear energy density functional theory

    DOE PAGESBeta

    Regnier, D.; Dubray, N.; Schunck, N.; Verriere, M.

    2016-05-13

    Here, accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics.

  17. Analytical methods for fissionable material determinations in the nuclear fuel cycle. Progress report, October 1, 1978-September 30, 1979

    SciTech Connect

    Waterbury, G.R.

    1980-03-01

    Work continues on the development of dissolution techniques for difficult-to-dissolve nuclear materials, the development of methods and automated instruments for plutonium, uranium, and thorium determinations, and the preparation of plutonium materials for the Safeguards Analytical Laboratory Evaluation (SALE) program and distribution by the National Bureau of Standards (NBS) as standard reference materials (SRMs). We are measuring the loner plutonium isotope half-lives, evaluating the isotope correlation techniques and the chemistry involved in the mass-spectrometric ion-bead techniques, and analyzing the SALE uranium materials. Completed subtasks include evaluations of various Teflon materials to recommend those acceptable for the dissolution apparatus developed at LASL, investigations of laser-enhanced dissolution of refractory materials, determinations of diverse ion effects on the microgram-sensitive method for determining uranium, fabrication of the first automated controlled-potential coulometric analyzer for determining plutonium, preparation of a /sup 244/Pu material for distribution by NBS as a SRM, and determination of the half-life of /sup 239/Pu. Work has been started on a spectrophotometric method for determining microgram quantities of plutonium, a microcomplexometric titration method for determining uranium, the use of new reagents for separations of plutonium, the preparation and packaging of a new lot of high-purity plutonium metal for distribution by NBS as a plutonium chemical SRM, and determination of half-lives of other plutonium isotopes.

  18. Determination of plutonium isotopes in low activity waste of NPP origin

    NASA Astrophysics Data System (ADS)

    Nikiforova, A.; Taskaeva, I.; Veleva, B.; Valova, Tz.; Slavchev, B.; Dimitrova, D.

    2006-01-01

    The inventory analysis of the alkaline low level liquid radioactive waste collected during more than 30 years of NPP “Kozloduy” operation requires determination of eighteen radioactive isotopes with different decay properties. Plutonium isotopes of interest are Pu-238, Pu-239/Pu-240, and Pu-242. The preliminary investigations of the supernatant phase of model and authentic waste samples showed essential challenges for determination of plutonium due to its various oxidation states and low concentration in the complex matrix. Plutonium concentration was determined in precipitate and supernatant after the calcium phosphate precipitation and in the different fractions of the anion exchange steps. The separation by anion exchange and final purification of plutonium fraction by extraction chromatography on TEVA resin (EiChroM Industries) was studied by variation of plutonium oxidation states. The sources were prepared by micro precipitation with NdF3 and counted by alpha spectrometry. As a result from the performed experiments, plutonium determination procedure was optimized and applied to real waste samples.

  19. Distribution of neptunium and plutonium in New Mexico lichen samples (Usnea arizonica) contaminated by atmospheric fallout

    DOE PAGESBeta

    Oldham, Jr., Warren J.; Hanson, Susan K.; Lavelle, Kevin B.; Miller, Jeffrey L.

    2015-08-30

    In this study, the concentrations of 237Np, 239Pu and 240Pu were determined in lichen samples (Usnea arizonica) that were collected from ten locations in New Mexico between 2011 and 2013 using isotope dilution inductively-coupled plasma mass spectrometry (ID-ICP-MS). The observed isotopic ratios for 237Np/239Pu and 240Pu/239Pu indicate trace contamination from global and regional fallout (e.g. Trinity test and atmospheric testing at the Nevada Test Site). The fact that actinide contamination is detected in recent lichen collections suggests continuous re-suspension of fallout radionuclides even 50 years after ratification of the Limited Test Ban Treaty.

  20. Monte Carlo simulations of differential die-away instrument for determination of fissile content in spent fuel assemblies

    NASA Astrophysics Data System (ADS)

    Lee, Tae-Hoon; Menlove, Howard O.; Swinhoe, Martyn T.; Tobin, Stephen J.

    2011-10-01

    The differential die-away (DDA) technique has been simulated by using the MCNPX code to quantify its capability of measuring the fissile content in spent fuel assemblies. For 64 different spent fuel cases of various initial enrichment, burnup and cooling time, the count rate and signal to background ratios of the DDA system were obtained, where neutron backgrounds are mainly coming from the 244Cm of the spent fuel. To quantify the total fissile mass of spent fuel, a concept of the effective 239Pu mass was introduced by weighing the relative contribution to the signal of 235U and 241Pu compared to 239Pu and the calibration curves of DDA count rate vs. 239Pu eff were obtained by using the MCNPX code. With a deuterium-tritium (DT) neutron generator of 10 9 n/s strength, signal to background ratios of sufficient magnitude are acquired for a DDA system with the spent fuel assembly in water.

  1. Sequential injection method for rapid and simultaneous determination of 236U, 237Np, and Pu isotopes in seawater.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Golser, Robin

    2013-11-19

    An automated analytical method implemented in a novel dual-column tandem sequential injection (SI) system was developed for simultaneous determination of (236)U, (237)Np, (239)Pu, and (240)Pu in seawater samples. A combination of TEVA and UTEVA extraction chromatography was exploited to separate and purify target analytes, whereupon plutonium and neptunium were simultaneously isolated and purified on TEVA, while uranium was collected on UTEVA. The separation behavior of U, Np, and Pu on TEVA-UTEVA columns was investigated in detail in order to achieve high chemical yields and complete purification for the radionuclides of interest. (242)Pu was used as a chemical yield tracer for both plutonium and neptunium. (238)U was quantified in the sample before the separation for deducing the (236)U concentration from the measured (236)U/(238)U atomic ratio in the separated uranium target using accelerator mass spectrometry. Plutonium isotopes and (237)Np were measured using inductively coupled plasma mass spectrometry after separation. The analytical results indicate that the developed method is robust and efficient, providing satisfactory chemical yields (70-100%) of target analytes and relatively short analytical time (8 h/sample). PMID:24134480

  2. Determination of plutonium in seawater using co-precipitation and inductively coupled plasma mass spectrometry with ultrasonic nebulisation

    NASA Astrophysics Data System (ADS)

    Eroglu, Ahmet E.; McLeod, Cameron W.; Leonard, Kinson S.; McCubbin, David

    1998-08-01

    A flow injection-inductively coupled plasma-mass spectrometric (FI-ICP-MS) procedure, utilising ultrasonic nebulisation with membrane desolvation (USN/MD), has been developed for the determination of plutonium (Pu) in seawater at fg l -1 concentration levels. Seawater samples (1 l), after filtration, were subjected to co-precipitation with NdF 3, followed by ion exchange to enrich Pu and to reject seawater matrix ions and co-existing uranium. The seawater concentrate (1.0 ml) was then analysed by FI-ICP-MS. The limit of detection for 239Pu in seawater based on an enrichment factor of 1000 was 5 fg l -1, and precision at the 0.80 pg l -1 level was 12% RSD. Accuracy was verified via recovery experiments, and by comparing survey data for the Irish Sea with that derived by standard methodology based on co-precipitation and α-spectrometry. Concentrations for dissolved 239Puand240Pu in the Irish Sea were in the range of 0.267-0.941 pg l -1 (0.614-2.164 mBq l -1) and 0.051-0.196 pg l -1 (0.428-1.646 mBq l -1), respectively.

  3. Seaborg's plutonium? A case study in nuclear forensics

    NASA Astrophysics Data System (ADS)

    Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

    2015-10-01

    Passive X-ray and gamma-ray analysis was performed on a curious sample from UC Berkeley's Hazardous Material Facility inventory, and the object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 ± 0.3 μg. These observations are consistent with the identification of this object as containing the 2.77-μg PuO2 (2.44 μg 239Pu) sample produced in 1942 and described by Seaborg and his collaborators as the first sample of 239Pu that was large enough to be weighed.

  4. Seaborg's Plutonium? A Case Study in Nuclear Forensics

    NASA Astrophysics Data System (ADS)

    Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

    2015-10-01

    Passive X-ray and gamma-ray analysis was performed on UC Berkeley's EH&S Sample S338. The object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 +- 0.3 μg. These observations are consistent with the identification of this object as containing the 2.77- μg PuO2 (2.44 μg 239Pu) sample produced in 1942 and described by Glenn Seaborg and his collaborators as the first sample of 239Pu that was large enough to be weighed. This work was supported in part by the U.S. Dept. of Energy National Nuclear Security Administration under Award No. DE-NA0000979.

  5. Sources of plutonium to the tropical Northwest Pacific Ocean (1943-1999) identified using a natural coral archive

    NASA Astrophysics Data System (ADS)

    Lindahl, Patric; Asami, Ryuji; Iryu, Yasufumi; Worsfold, Paul; Keith-Roach, Miranda; Choi, Min-Seok

    2011-03-01

    The Pu isotopes, 239Pu and 240Pu, were determined in annually-banded skeletons of an accurately dated (1943-1999) modern coral ( Porites lobata) from Guam Island to identify historical Pu sources to the tropical Northwest Pacific Ocean. Activity concentrations of 239+240Pu and 240Pu/ 239Pu atom ratios were determined in the dated coral bands using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands and global fallout were identified as the two main sources. The Guam site was dominated by PPG close-in fallout in the 1950s, with an average 240Pu/ 239Pu atom ratio of 0.315 ± 0.005. In addition, a higher 240Pu/ 239Pu atom ratio (0.456 ± 0.020) was observed that could be attributed to fallout from the "Ivy Mike" thermonuclear detonation in 1952. The atom ratio decreased in the 1960s and 1970s due to increase in the global fallout with a low 240Pu/ 239Pu atom ratio (˜0.18). Recent coral bands (1981-1999) are dominated by the transport of remobilised Pu, with high 240Pu/ 239Pu atom ratios, from the Marshall Islands to Guam Island along the North Equatorial Current (NEC). This remobilised Pu was estimated to comprise 69% of the total Pu in the recent coral bands, although its contribution was variable over time.

  6. Concurrent determination of 237Np and Pu isotopes using ICP-MS: analysis of NIST environmental matrix standard reference materials 4357, 1646a, and 2702.

    PubMed

    Matteson, Brent S; Hanson, Susan K; Miller, Jeffrey L; Oldham, Warren J

    2015-04-01

    An optimized method was developed to analyze environmental soil and sediment samples for (237)Np, (239)Pu, and (240)Pu by ICP-MS using a (242)Pu isotope dilution standard. The high yield, short time frame required for analysis, and the commercial availability of the (242)Pu tracer are significant advantages of the method. Control experiments designed to assess method uncertainty, including variation in inter-element fractionation that occurs during the purification protocol, suggest that the overall precision for measurements of (237)Np is typically on the order of ± 5%. Measurements of the (237)Np concentration in a Peruvian Soil blank (NIST SRM 4355) spiked with a known concentration of (237)Np tracer confirmed the accuracy of the method, agreeing well with the expected value. The method has been used to determine neptunium and plutonium concentrations in several environmental matrix standard reference materials available from NIST: SRM 4357 (Radioactivity Standard), SRM 1646a (Estuarine Sediment) and SRM 2702 (Inorganics in Marine Sediment). PMID:25644752

  7. Methods for the assessment of long-lived radionuclides in humans resulting from nuclear activities or accidents: Fission track analysis of trace amounts plutonium-239 and a copper hexacyanoferrate kit for monitoring radiocaesium

    NASA Astrophysics Data System (ADS)

    Johansson, Lena Camilla

    Fission track analysis (FTA) was developed to be applied to ultra-low levels of 239Pu in bioassay samples. An analytical protocol was established for the FTA processing. The detection limit was determined to 1.5 μBq and the calibration constant was 24 fission fragments per μBq 239Pu. Naturally occurring nuclides of thorium and uranium, present in biological and environmental samples, did not interfere in the determination of 239Pu. Self-absorption of fission fragments was shown to be insignificant. The study included the determination of 239Pu in urine samples from twenty Chernobyl clean-up workers. All urine samples contained activities below the detection limit for radioanalytical analysis using alpha spectrometry (0.5 mBq). Seven of the samples were further investigated using a thermal ionization mass spectrometer with a sensitivity of 106 atoms 239Pu. The content of 239Pu in the samples showed to be below 1μBq (106 atoms), with only one exception. It was not possible to draw any major conclusions from the 239Pu results, regarding the clean-up workers' exposure from radionuclides released by the Chernobyl accident. A kit was designed for selective adsorption of radiocaesium in urine samples to be used in situ by contaminated subjects. The kit consisted of copper hexacyanoferrate impregnated cotton filters held by filter holders for sample flow-through. After use, the adsorbed fraction of caesium was >=90% in urine samples. The kit facilitates the screening of a population exposed to radiocaesium. Parameters influencing the adsorption efficiency, such as potassium, sodium and calcium concentration of the sample and the sample pH, were investigated and shown to be insignificant for urine samples.

  8. Rapid multisample analysis for simultaneous determination of anthropogenic radionuclides in marine environment.

    PubMed

    Qiao, Jixin; Shi, Keliang; Hou, Xiaolin; Nielsen, Sven; Roos, Per

    2014-04-01

    An automated multisample processing flow injection (FI) system was developed for simultaneous determination of technetium, neptunium, plutonium, and uranium in large volume (200 L) seawater. Ferrous hydroxide coprecipitation was used for the preliminary sample treatment providing the merit of simultaneous preconcentration of all target radionuclides. Technetium was separated from the actinides via valence control of technetium (as Tc(VII)) in a ferric hydroxide coprecipitation. A novel preseparation protocol between uranium and neptunium/plutonium fractions was developed based on the observation of nearly quantitative dissolution of uranium in 6 mol/L sodium hydroxide solution. Automated extraction (TEVA for technetium and UTEVA for uranium) and anion exchange (AGMP-1 M for plutonium and neptunium) chromatographic separations were performed for further purification of each analyte within the FI system where four samples were processed in parallel. Analytical results indicate that the proposed method is robust and straightforward, providing chemical yields of 50-70% and improved sample throughput (3-4 d/sample). Detection limits were 8 mBq/m(3) (0.013 pg/L), 0.26 μBq/m(3) (0.010 fg/L), 23 μBq/m(3) (0.010 fg/L), 84 μBq/m(3) (0.010 fg/L) and 0.6 mBq/m(3) (0.048 ng/L) for (99)Tc, (237)Np, (239)Pu, (240)Pu and (238)U for 200 L seawater, respectively. The unique feature of multiradionuclide and multisample simultaneous processing vitalizes the developed method as a powerful tool in obtaining reliable data with reduced analytical cost in both radioecology studies and nuclear emergency preparedness. PMID:24617716

  9. Distribution of sup 137 Cs, sup 90 Sr, sup 238 Pu, sup 239 Pu, sup 241 Am and sup 244 Cm in Pond B, Savannah River Site

    SciTech Connect

    Whicker, F.W. ); Pinder, J.E. III; Bowling, J.W. ); Alberts, J.J. . Marine Inst.); Brisbin, I.L. Jr. )

    1989-05-01

    The gradual senescence of present-day operating nuclear facilities, and resultant contamination of aquatic and terrestrial ecosystems, emphasize the importance of understanding the behavior of radionuclides in the environment. Observations and deductions concerning mechanisms of radionuclide transport can contribute significantly to knowledge of fundamental ecological processes. This study emphasized the ecosystem-level distribution of several long-lived radionuclides in an abandoned reactor cooling impoundment after a twenty year period of chemical and biological equilibration. 90 refs., 14 figs., 5 tabs.

  10. Depth profile of 236U/238U in soil samples in La Palma, Canary Islands

    PubMed Central

    Srncik, M.; Steier, P.; Wallner, G.

    2011-01-01

    The vertical distribution of the 236U/238U isotopic ratio was investigated in soil samples from three different locations on La Palma (one of the seven Canary Islands, Spain). Additionally the 240Pu/239Pu atomic ratio, as it is a well establish tool for the source identification, was determined. The radiochemical procedure consisted of a U separation step by extraction chromatography using UTEVA® Resin (Eichrom Technologies, Inc.). Afterwards Pu was separated from Th and Np by anion exchange using Dowex 1x2 (Dow Chemical Co.). Furthermore a new chemical procedure with tandem columns to separate Pu and U from the matrix was tested. For the determination of the uranium and plutonium isotopes by alpha spectrometry thin sources were prepared by microprecipitation techniques. Additionally these fractions separated from the soil samples were measured by Accelerator Mass Spectrometry (AMS) to get information on the isotopic ratios 236U/238U, 240Pu/239Pu and 236U/239Pu, respectively. The 236U concentrations [atoms/g] in each surface layer (∼2 cm) were surprisingly high compared to deeper layers where values around two orders of magnitude smaller were found. Since the isotopic ratio 240Pu/239Pu indicated a global fallout signature we assume the same origin as the probable source for 236U. Our measured 236U/239Pu value of around 0.2 is within the expected range for this contamination source. PMID:21481502

  11. Rapid determination of plutonium isotopes in environmental samples using sequential injection extraction chromatography and detection by inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2009-10-01

    This article presents an automated method for the rapid determination of 239Pu and 240Pu in various environmental samples. The analytical method involves the in-line separation of Pu isotopes using extraction chromatography (TEVA) implemented in a sequential injection (SI) network followed by detection of isolated analytes with inductively coupled plasma mass spectrometry (ICP-MS). The method has been devised for the determination of Pu isotopes at environmentally relevant concentrations, whereby it has been successfully applied to the analyses of large volumes/amounts of samples, for example, 100-200 g of soil and sediment, 20 g of seaweed, and 200 L of seawater following analyte preconcentration. The investigation of the separation capability of the assembled SI system revealed that up to 200 g of soil or sediment can be treated using a column containing about 0.70 g of TEVA resin. The analytical results of Pu isotopes in the reference materials showed good agreement with the certified or reference values at the 0.05 significance level. Chemical yields of Pu ranged from 80 to 105%, and the decontamination factors for uranium, thorium, mercury and lead were all above 10(4). The duration of the in-line extraction chromatographic run was <1.5 h, and the proposed setup was able to handle up to 20 samples (14 mL each) in a fully automated mode using a single chromatographic column. The SI manifold is thus suitable for rapid and automated determination of Pu isotopes in environmental risk assessment and emergency preparedness scenarios. PMID:19722516

  12. Determination of 238Pu(n ,f ) and 236Np(n ,f ) cross sections using surrogate reactions

    NASA Astrophysics Data System (ADS)

    Pal, A.; Santra, S.; Nayak, B. K.; Mahata, K.; Desai, V. V.; Chattopadhyay, D.; Tripathi, R.

    2015-05-01

    The cross sections for 238Pu(n ,f ) reaction for equivalent neutron energy of 13.0-22.0 MeV have been determined by the "surrogate ratio" method by measuring 235U(6Li,d f ) and 232Th(6Li,d f ) transfer induced fission reactions proceeding through the excited fissioning nuclei 239Pu and 236U, respectively, and using 235U(n ,f ) cross-section data as the reference. Similarly, the cross sections for the 236Np(n ,f ) reaction in the equivalent neutron energy range 9.9-22.0 MeV have been determined by the "hybrid surrogate ratio" method via the measurements of 235U(6Li,α f ) and 235U(6Li,d f ) transfer induced fission reactions, using 238Pu(n ,f ) cross-section data as the reference. The empire-3.1 calculations for 238Pu(n ,f ) and 236Np(n ,f ) cross sections agree well with the present data, however, they are slightly underestimated by the endf/b-vii.1 evaluations.

  13. LLD Determination for PFP Residues Using the ANTECH Calorimeters

    SciTech Connect

    WESTSIK, G.A.

    2003-07-07

    The Plutonium Finishing Plant (PFP) facility performs waste characterization measurements for disposal of transuranic waste (TRU) at the Waste Isolation Pilot Plant (WIPP). The WIPP's performance assessment requires monitoring and tracking of the following ten radionuclides in the waste that is accepted and disposed of at the WIPP facility. Activities and mass values must be reported for: {sup 241}Am, {sup 238}Pu, {sup 239}Pu, {sup 240}Pu, {sup 242}Pu, {sup 233}U, {sup 234}U, {sup 238}U, {sup 90}Sr and {sup 137}Cs on a payload container basis. In addition the system must be able to report other nuclides, which contribute to the FGE, decay heat or contribute to more than 95% of the total radiological hazard. PFP reports the activity and mass of these radionuclides when positively identified in any waste container. In situations where one of the 10 WIPP tracked radionuclides is not positively identified on a PFP assay, PFP either reports a ''zero'', indicating the nuclide was not positively identified in the waste assay and is not identified by the acceptable knowledge (AK), or ''Determination for PFP Residues using the ANTECH Calorimeters''. This revision addresses the LLD for all (AR-1, AR-5, AR-8, P-13, P-14, P-15, and Q-1) of the calorimeters. This revision also makes significant changes in the way in which the LLD is evaluated and reported. The primary change in the evaluation is from using base power measurements to using zero power measurements. This is because over time the base power can fluctuate do to seasonal variations in temperature as well as other effects. Basing the evaluation on the base power causes the LLD to be unacceptably high on some systems. Using the 0 power measurements is more consistent

  14. Effects of combined exposure of F344 rats to radiation and chronically inhaled cigarette smoke

    SciTech Connect

    Finch, G.L.; Nikula, K.J.; Barr, E.B.

    1995-12-01

    Nuclear workers may be exposed to radiation in various forms, such as low-LET {gamma}-irradiation or {alpha}-irradiation from inhaled {sup 239}PuO{sub 2} particles. These workers may then have increased risk for lung cancer compared to the general population. Of additional concern is the possibility that interactions between radiation and other carcinogens may increase the risk of cancer induction, compared to the risks from either type of agent alone. An important and common lung carcinogen is cigarette smoke. The purpose of this project is to better determine the combined effects of chronically inhaled cigarette smoke and either inhaled {sup 239}PuO{sub 2} or external, thoracic X-irradiation on the induction of lung cancer in rats. Histologic and dosimetric evaluations of rats in the CS + {sup 239}PuO{sub 2} study continue, and the study of CS + X rays is beginning.

  15. Assessment of Degree of Applicability of Benchmarks for Gadolinium Using KENO V.a and the 238-Group SCALE Cross-Section Library

    SciTech Connect

    Goluoglu, S.

    2003-12-01

    A review of the degree of applicability of benchmarks containing gadolinium using the computer code KENO V.a and the gadolinium cross sections from the 238-group SCALE cross-section library has been performed for a system that contains {sup 239}Pu, H{sub 2}O, and Gd{sub 2}O{sub 3}. The system (practical problem) is a water-reflected spherical mixture that represents a dry-out condition on the bottom of a sludge receipt and adjustment tank around steam coils. Due to variability of the mixture volume and the H/{sup 239}Pu ratio, approximations to the practical problem, referred to as applications, have been made to envelop possible ranges of mixture volumes and H/{sup 239}Pu ratios. A newly developed methodology has been applied to determine the degree of applicability of benchmarks as well as the penalty that should be added to the safety margin due to insufficient benchmarks.

  16. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    SciTech Connect

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  17. Resolving global versus local/regional Pu sources in the environment using sector ICP-MS

    USGS Publications Warehouse

    Ketterer, M.E.; Hafer, K.M.; Link, C.L.; Kolwaite, D.; Wilson, Jim; Mietelski, J.W.

    2004-01-01

    Sector inductively coupled plasma mass spectrometry is a versatile method for the determination of plutonium activities and isotopic compositions in samples containing this element at fallout levels. Typical detection limits for 239+240Pu are 0.1, 0.02 and 0.002 Bq kg -1Pu for samples sizes of 0.5 g, 3 g, and 50 g of soil, respectively. The application of sector ICP-MS-based Pu determinations is demonstrated in studies in sediment chronology, soil Pu inventory and depth distribution, and the provenance of global fallout versus local or regional Pu sources. A sediment core collected from Sloans Lake (Denver, Colorado, USA) exhibits very similar 137Cs and 239+240Pu activity profiles; 240Pu/239Pu atom ratios indicate possible small influences from the Nevada Test Site and/or the Rocky Flats Environmental Technology Site. An undisturbed soil profile from Lockett Meadow (Flagstaff, Arizona, USA) exhibits an exponential decrease in 239+240Pu activity versus depth; 240Pu/239Pu in the top 3 cm is slightly lower than the global fallout range of 0.180 ?? 0.014 due to possible regional influence of Nevada Test Site fallout. The 239??240Pu inventory at Lockett Meadow is 56 ?? 4 Bq m-2, consistent with Northern Hemisphere mid-latitude fallout. Archived NdF3 sources, prepared from Polish soils, demonstrate that substantial 239+240Pu from the 1986 Chernobyl disaster has been deposited in north eastern regions of Poland; compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/239pu and 241Pu/239Pu co-vary and range from 0.186-0.348 and 0.0029-0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407??[240Pu/239Pu] - 0.0413; r2 = 0.9924). ?? The Royal Society of Chemistry 2004.

  18. Identifying Sources of Non-fallout Nuclear Contamination in Hudson River Sediments by Plutonium and Neptunium isotope ratios.

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.

    2002-12-01

    .050 and 0.070, 237Np/239Pu ranges between 0.003 and 0.141, and 241Pu/239Pu ranges between 0.00037and 0.00074). Isotopic analysis of sediments from the lower Hudson River also indicates contamination that is non-fallout in origin (240Pu/239Pu ranges between 0.13 and 0.14, 237Np/239Pu ranges between 0.35 and 0.39, and 241Pu/239Pu ranges between 0.0013 and 0.0016). Isotopic analysis of sediments from the upper Hudson River, above its confluence with the Mohawk, indicates contamination that is largely derived from global fallout (240Pu/239Pu ranges between 0.15 and 0.18, 237Np/239Pu ranges between 0.42 and 0.53, and 241Pu/239Pu ranges between 0.0019 and 0.0023). Initial results clearly indicate contributions from at least one source of non-fallout contamination to Mohawk and Hudson River sediments. Given the geographic location of the Mohawk River sample site, the source is most likely KAPL. Additional work is necessary to determine the source of non-fallout contamination to the lower Hudson River coring site. Although the proximity of this site to IPNPP may suggest that this facility is a source, the isotopic compositions measured to date are consistent with a mixture of global fallout and material similar to that collected at the Mohawk River site. The data presented above, demonstrate the utility of using Pu and Np isotopic ratios to identify contamination originating form non-fallout sources located within the Hudson River drainage basin.

  19. Neutron absorbers and detector types for spent fuel verification using the self-interrogation neutron resonance densitometry

    NASA Astrophysics Data System (ADS)

    Rossa, Riccardo; Borella, Alessandro; Labeau, Pierre-Etienne; Pauly, Nicolas; van der Meer, Klaas

    2015-08-01

    The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive non-destructive assay (NDA) technique that is proposed for the direct measurement of 239Pu in a spent fuel assembly. The insertion of neutron detectors wrapped with different neutron absorbing materials, or neutron filters, in the central guide tube of a PWR fuel assembly is envisaged to measure the neutron flux in the energy region close to the 0.3 eV resonance of 239Pu. In addition, the measurement of the fast neutron flux is foreseen. This paper is focused on the determination of the Gd and Cd neutron filters thickness to maximize the detection of neutrons within the resonance region. Moreover, several detector types are compared to identify the optimal condition and to assess the expected total neutron counts that can be obtained with the SINRD measurements. Results from Monte Carlo simulations showed that ranges between 0.1-0.3 mm and 0.5-1.0 mm ensure the optimal conditions for the Gd and Cd filters, respectively. Moreover, a 239Pu fission chamber is better suited to measure neutrons close to the 0.3 eV resonance and it has the highest sensitivity to 239Pu, in comparison with a 235U fission chamber, with a 3He proportional counter, and with a 10B proportional counter. The use of a thin Gd filter and a thick Cd filter is suggested for the 239Pu and 235U fission chambers to increase the total counts achieved in a measurement, while a thick Gd filter and a thin Cd filter are envisaged for the 3He and 10B proportional counters to increase the sensitivity to 239Pu. We concluded that an optimization process that takes into account measurement time, filters thickness, and detector size is needed to develop a SINRD detector that can meet the requirement for an efficient verification of spent fuel assemblies.

  20. Analysis of actinides in an ombrotrophic peat core - evidence of post-depositional migration of fallout radionuclides

    NASA Astrophysics Data System (ADS)

    Quinto, Francesca; Hrnecek, Erich; Krachler, Michael; Shotyk, William; Steier, Peter; Winkler, Stephan R.

    2013-04-01

    Plutonium (239Pu, 240Pu, 241Pu, 242Pu) and uranium (236U, 238U) isotopes were analyzed in an ombrotrophic peat core from the Black Forest, Germany, representing the last 80 years of atmospheric deposition. The reliable determination of these isotopes at ultra-trace levels was possible using ultra-clean laboratory procedures and accelerator mass spectrometry. The 240Pu/239Pu isotopic ratios are constant along the core with a mean value of 0.19 ±0.02 (N = 32). This result is consistent with the acknowledged average 240Pu/239Pu isotopic ratio from global fallout in the Northern Hemisphere. The global fallout origin of Pu is confirmed by the corresponding 241Pu/239Pu (0.0012 ±0.0005) and 242Pu/239Pu (0.004 ± 0.001) isotopic ratios. The identification of the Pu isotopic composition characteristic for global fallout in peat layers pre-dating the period of atmospheric atom bomb testing (AD 1956 - AD 1980) is a clear evidence of the migration of Pu downwards the peat profile. The maximum of global fallout derived 236U is detected in correspondence to the age/depth layer of maximum stratospheric fallout (AD 1963). This finding demonstrates that the 236U bomb peak can be successfully used as an independent chronological marker complementing the 210Pb dating of peat cores. The profiles of the global fallout derived 236U and 239Pu are compared with those of 137Cs and 241Am. As typical of ombrothrophic peat, the temporal fallout pattern of 137Cs is poorly retained. Similarly like for Pu, post-depositional migration of 241Am in peat layers preceding the era of atmospheric nuclear tests is observed.

  1. Determination the total neutron yields of several semiconductor compounds using various alpha emitters

    NASA Astrophysics Data System (ADS)

    Abdullah, Ramadhan Hayder; Sabr, Barzan Nehmat

    2016-03-01

    In the present work, the cross-sections of (α,n) reactions available in the literature as a function of α-particle energies for light and medium elements have been rearranged for α-particle energies from near threshold up to 10 MeV in steps of (0.050MeV) using the (Excel and Matlab) computer programs. The obtained data were used to calculate the neutron yields (n/106α) using the quick basic-computer program (Simpson Rules). The stopping powers of alpha particle energies from near threshold to 10 MeV for light and medium elements such as (nat.Be,10B,11B,13C,14N,nat.O,nat.F,nat.Mg,nat.Al,29Si,30Si, nat.P and 46.48Ti) have been calculated using the Zeigler formula. The kinetic energies (Tα) and the branching ratios of each α-emitters such as (211Bi, 210Po, 211Po, 215Po, 217At, 218Rn, 219Rn, 222Rn, 224Ra, 226Ra, 215Th, 228Th, 232U, 234U, 236U, 238U, 238Pu, 239Pu, 241Am, 245Es, 252Fm, 254Fm, 256Fm, 257Fm and 257Md) are taken into consideration to calculate the mean kinetic energy . The polynomial expressions were used to fitting the calculated weighted average of neutron yields (n/106α) for natural light and medium elements such as (Be, B, C, N, O, F, Mg, Al, Si, P and Ti) to determine the adopted neutron yields from the best fitting equation with minimum (CHISQ) at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gx/ppmi) of the mentioned natural light and medium elements have been calculated using the adopted neutron yields (n/106α) from the fitting equations at mean kinetic energies of various α-emitters. The total neutron yields (n/s/gα-emitters/gcompounds) of semiconductor compounds such as (AlN, AlP, BN, BP, SiC, TiO2, BeSiN2, MgCN2, MgSiN2 and MgSiP2) have been calculated by mixing (1gram) of compounds with (1gram) of pure α-emitters using the quick basic computer program. The aim of the present work is to constructed and fabricate the neutron sources theoretically

  2. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 5 (MACROBATCH 6)

    SciTech Connect

    Bannochie, C.; Bibler, N.; Diprete, D.

    2010-02-04

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that ''The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115''. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Tank 40 (Sludge Batch 4 (SB4)), Sludge Batch 5 (SB5) that was transferred to Tank 40 from Tank 51, and H-Canyon Np transfers completed after the start of processing. The blend of sludge in Tank 40 is also referred to as Macrobatch 6 (MB6). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use

  3. Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives.

    PubMed

    Lindahl, Patric; Andersen, Morten B; Keith-Roach, Miranda; Worsfold, Paul; Hyeong, Kiseong; Choi, Min-Seok; Lee, Sang-Hoon

    2012-04-01

    Historical (239)Pu activity concentrations and (240)Pu/(239)Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher (240)Pu/(239)Pu atom ratios (>0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the (240)Pu/(239)Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location. PMID:21890207

  4. Experimental determination of contaminant metal mobility as a function of temperature, time and solution chemistry. 1997 annual progress report

    SciTech Connect

    Carroll, S.; Bruton, C.; O'Day, P.; Sahai, N.

    1997-01-01

    'Strontium is significantly more mobile than other hazardous radioactive metals. Its partitioning between aqueous and solid phases is controlled by reactions that occur at the interface between natural waters and minerals. At a groundwater site in Hanford (200-BP-5), the aerial extent of the {sup 90}Sr plume is 100 times larger than the aerial extent of the {sup 137}Cs and the {sup 239}Pu plumes. Similarly, contaminated, perched watertables at INEL have much higher aqueous concentrations of {sup 90}Sr than {sup 137}Cs, presumably because Cs is preferentially sorbed to solids (Duncan 1995). Under high physical flow conditions, such as those in the highly fractured rock at Hanford and INEL, {sup 90}Sr present in plumes may spread off-site and cause contamination of aquifers or other water sources. Geochemical factors that may contribute to the overall mobility of Sr in natural waters are the solubilities of phases such as strontianite (SrCO{sub 3}) and formation of strong complexes with sulfate and nitrate. Although {sup 90}Sr is mobilized in natural waters in these examples, significant concentrations may also be present in solid phases. Sorption experiments using a wide variety of substrates at room temperature have shown that Sr is removed from solution under certain conditions. Additionally, strontianite (SrCO{sub 3}) may precipitate at low Sr concentrations in the pH range of waters in contact with basaltic rocks, which varies between pH 8 and 10. Waters contain variable amounts of carbonate owing to atmospheric interactions; the partial pressure of CO{sub 2} is about 10 x 3.5 atm in air and commonly as high as 10 x 2.5 atm in soils. The objective of this work is to determine the fundamental data needed to predict the behavior of strontium at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments, which track changes in solution composition

  5. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 4 MACROBATCH 5

    SciTech Connect

    Bannochie, C; Ned Bibler, N; David Diprete, D

    2008-05-30

    The Waste Acceptance Product Specifications (WAPS)1 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP)2 and Waste Form Qualification Report (WQR)3. However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the previous contents of Tank 40 (Sludge Batch 3) and the sludge that was transferred to Tank 40 from Tank 51. The blend of sludge from Tank 51 and Tank 40 defines Sludge Batch 4 (also referred to as Macrobatch 5 (MB5)). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use this list and the activities as one of

  6. A rapid and accurate method for the determination of plutonium in food using magnetic sector ICP-MS with an ultra-sonic nebuliser and ion chromatography.

    PubMed

    Evans, P; Elahi, S; Lee, K; Fairman, B

    2003-02-01

    In the event of a nuclear incident it is essential that analytical information on the distribution and level of contamination is available. An ICP-MS method is described which can provide data on plutonium contamination in food within 3 h of sample receipt without compromising detection limits or accuracy relative to traditional counting methods. The method can also provide simultaneous determinations of americium and neptunium. Samples were prepared by HNO3 closed-vessel microwave digestion, evaporated to dryness and diluted into a mobile phase comprising 1.5 M HNO3 and 0.1 mM 2,6-pyridinedicarboxylic acid. A commercially available polystyrene-divinylbenzene ion chromatography column provides on-line separation of 239Pu and 238U reducing the impact of the 238U1H interference. Oxidation of the sample using H2O2 ensures all Pu is in the Pu(+4) state. The oxidation also displaces Np away from the solvent front by changing the oxidation state from Np(+3) to Np(+4) and produces the insoluble Am(+4) ion. Simultaneous Pu, Am and Np analyses therefore require omission of the oxidation stage and some loss of Pu data quality. Analyses were performed using a magnetic sector ICP-MS (Finnigan MAT Element). The sample is introduced to the plasma via an ultrasonic nebuliser-desolvation unit (Cetac USN 6000AT+). This combination achieves an instrumental sensitivity of 238U > 2 x 10(7) cps/ppb and removes hydrogen from the sample gas, which also inhibits the formation of 238U1H. The net effect of the improved sample introduction conditions is to achieve detection levels for Pu of 0.020 pg g(-1) (4.6 x 10(-2) Bq kg(-1)) which is significantly below 1/10th of the most stringent EU (European Union) legislation, currently 0.436 pg g(-1) (1 Bq kg(-1)) set for baby food. The new method was evaluated with a range of biological samples ranging from cabbage to milk and meat. Recovery of Pu agrees with published values (100% +/- 20%). PMID:12619774

  7. Combined use of medium mass resolution and desolvation introduction system for accurate plutonium determination in the femtogram range by inductively coupled plasma-sector-field mass spectrometry

    NASA Astrophysics Data System (ADS)

    Pointurier, Fabien; Pottin, Anne-Claire; Hémet, Philippe; Hubert, Amélie

    2011-03-01

    Formation of a polyatomic species made of an atom of a heavy element like lead, mercury or iridium, and atoms abundant in plasma (argon, nitrogen, oxygen, and hydrogen) when using an inductively coupled plasma-sector-field mass spectrometer (ICP-SFMS) may lead to false detection of femtograms (fg) of plutonium or bias in the measured concentrations. Mathematical corrections, based on the measurement of heavy element concentrations in the sample solutions and determination of the extents of formation of the polyatomic interferences, are efficient but time-consuming and degrade detection limits. We describe and discuss a new method based on the combination of, on the one hand, medium mass resolution (MR) of the ICP-SFMS to separate plutonium isotopes physically from interfering polyatomic species, and, on the other, use of a desolvation introduction system (DIS) to enhance sensitivity, thus partly compensating for the loss of transmission due to use of a higher resolution. Plutonium peaks are perfectly separated from the major interfering species (PbO 2, HgAr, and IrO 3) with a mass resolution of ~ 4000. The resulting nine-fold transmission loss is partly compensated by a five-fold increase in sensitivity obtained with the DIS and a lower background. The instrumental detection limits for plutonium isotopes, calculated for measurements of pure synthetic solutions, of the new method (known as MR-DIS method) and of the one currently used in the laboratory (LR method), based on a low mass resolution equal to 360, a microconcentric nebulizer and two in-line cooled spray chambers, are roughly equivalent, at around 0.2 fg ml - 1 . Regarding the measurement of real-life samples, the results obtained with both methods agree and the corresponding analytical detection limits for plutonium isotopes 239Pu, 240Pu and 241Pu are of a few fg·ml - 1 of sample solution, slightly lower with the MR-DIS method than with the current LR method. Although less sensitive than other plutonium

  8. Determination of plutonium in environmental samples by AMS and alpha spectrometry.

    PubMed

    Hrnecek, E; Steier, P; Wallner, A

    2005-01-01

    Environmental samples from nuclear weapons test sites at the atolls of Mururoa and Fangataufa (French Polynesia, south Pacific) have been analyzed for their content of plutonium isotopes by applying the independent techniques of decay counting (Alpha Spectrometry) and accelerator mass spectrometry (AMS). Here, we propose the combination of both techniques which results in a maximum of information on the isotopic signature of Pu in environmental samples. Plutonium was chemically separated from the bulk material by anion exchange. (242)Pu was used as an internal standard for both AMS and alpha spectrometry. The samples for alpha spectrometry were prepared by micro-precipitation with NdF(3). After alpha spectrometry, the samples were reprocessed for AMS. Pu was co-precipitated with Fe(OH)(3) and finally, solid samples were prepared. At the VERA (Vienna Environmental Research Accelerator) facility, the various Pu isotopes were separated by their isotopic masses and quantified by the AMS technique. A good agreement of the results obtained from the AMS measurements was found with those obtained from Alpha Spectrometry. Overall, the data agree on average within 10% of each other. Isotope ratios for (238)Pu, (239)Pu and (240)Pu can be extracted from our investigations. Alpha spectrometry delivers data for the (238)Pu and the combination of ((239+240))Pu concentrations in those samples. In addition, the AMS technique provides information on the individual concentrations of (240)Pu and (239)Pu. PMID:15982894

  9. A fast semi-quantitative method for Plutonium determination in an alpine firn/ice core

    NASA Astrophysics Data System (ADS)

    Gabrieli, J.; Cozzi, G.; Vallelonga, P.; Schwikowski, M.; Sigl, M.; Boutron, C.; Barbante, C.

    2009-04-01

    Plutonium is present in the environment as a consequence of atmospheric nuclear tests carried out in the 1960s, nuclear weapons production and releases by the nuclear industry over the past 50 years. Plutonium, unlike uranium, is essentially anthropogenic and it was first produced and isolated in 1940 by deuteron bombardment of uranium in the cyclotron of Berkeley University. It exists in five main isotopes, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, derived from civilian and military sources (weapons production and detonation, nuclear reactors, nuclear accidents). In the environment, 239Pu is the most abundant isotope. Approximately 6 tons of 239Pu have been released into the environment as a result of 541 atmospheric weapon tests Nuclear Pu fallout has been studied in various environmental archives, such as sediments, soil and herbarium grass. Mid-latitude ice cores have been studied as well, on Mont Blanc, the Western Alps and on Belukha Glacier, Siberian Altai. We present a Pu record obtained by analyzing 52 discrete samples of an alpine firn/ice core from Colle Gnifetti (M. Rosa, 4450 m a.s.l.), dating from 1945 to 1991. The239Pu signal was recorded directly, without preliminary cleaning or preconcentration steps, using an ICP-SFMS (Thermo Element2) equipped with a desolvation system (APEX). 238UH+ interferences were negligible for U concentrations lower than 50 ppt as verified both in spiked fresh snow and pre-1940 ice samples. The shape of 239Pu profile reflects the three main periods of atmospheric nuclear weapons testing: the earliest peak starts in 1954/55 to 1958 and includes the first testing period which reached a maximum in 1958. Despite a temporary halt in testing in 1959/60, the Pu concentration decreased only by half with respect to the 1958 peak. In 1961/62 Pu concentrations rapidly increased reaching a maximum in 1963, which was about 40% more intense than the 1958 peak. After the sign of the "Limited Test Ban Treaty" between USA and URSS in 1964, Pu

  10. Determination of Reportable Radionuclides for DWPF Sludge Batch 3 (Macrobatch 4)

    SciTech Connect

    Bannochie, C

    2005-05-01

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that ''The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115''. As part of the strategy to meet WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, IAEA Safeguards Reporting for HLW, requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The Defense Waste Processing Facility (DWPF) is receiving radioactive sludge slurry from High Level Waste Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the previous contents of Tank 40 (Sludge Batch 2) and the sludge that was transferred to Tank 40 from Tank 51. The blend of sludge from Tank 51 and Tank 40 defines Macrobatch 4 (also referred to as Sludge Batch 3). This report develops the list of reportable radionuclides and associated activities and determines the radionuclide activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the

  11. Off-Site Radiation Exposure Review Project: Phase 2 soils program

    SciTech Connect

    McArthur, R.D.; Miller, F.L. Jr.

    1989-12-01

    To help estimate population doses of radiation from fallout originating at the Nevada Test Site, soil samples were collected throughout the western United States. Each sample was prepared by drying and ball-milling, then analyzed by gamma-spectrometry to determine the amount of {sup 137}Cs it contained. Most samples were also analyzed by chemical separation and alpha-spectrometry to determine {sup 239 + 240}Pu and by isotope mass spectroscopy to determine the ratios of {sup 240}Pu to {sup 239}Pu and {sup 241}Pu to {sup 239}Pu. The total inventories of cesium and plutonium at 171 sites were computed from the results. This report describes the sample collection, processing, and analysis, presents the analytical results, and assesses the quality of the data. 10 refs., 9 figs., 12 tabs.

  12. FFTF (Fast Flux Test Facility) Reactor Characterization Program: Absolute Fission-rate Measurements

    SciTech Connect

    Fuller, J.L.; Gilliam, D.M.; Grundl, J.A.; Rawlins, J.A.; Daughtry, J.W.

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  13. FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS

    SciTech Connect

    FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  14. Calibration of a large hyperpure germanium array for in-vivo detection of the actinides with a tissue-equivalent torso phantom

    SciTech Connect

    Berger, C.D.; Lane, B.H.

    1983-01-01

    For calibration of the array for internally deposited /sup 238/Pu, /sup 239/Pu, and /sup 241/Am, a tissue-equivalent anthropomorphic phantom, was used for efficiency determinations at the ORNL facility. This phantom consists of a tissue-equivalent torso into which is imbedded an adult male skeleton, interchangeable organs containing a homogeneous distribution of various radionuclides, and two sets of chest overlay plates for simulation of progressively thicker tissue over the chest, as well as differing thoracic fat contents. (PSB)

  15. Comparison of attenuation correction methods for TGS and SGS: Do we really need selenium-75?

    SciTech Connect

    Estep, R.J.; Prettyman, T.H.; Sheppard, G.A.

    1996-09-01

    We compared attenuation-coefficient mapping techniques for use in tomographic gamma scanner (TGS) image reconstructions to determine whether there is a significant improvement when using fully coupled methods. For the constrained least-squares image reconstruction method tested here, we found no significant improvement. We also compared the effectiveness of different transmission source combinations for 129- and 414-keV {sup 239}Pu TGS assays. We concluded that the best source combination for TGS assays of {sup 239}Pu and other isotopes is a mixture of {sup 133}Ba, {sup 54}Mn, and {sup 60}Co. Three other source combinations were found to be at least as effective as {sup 75}Se.

  16. Analysis of fissionable material using delayed gamma rays from photofission

    SciTech Connect

    Hollas, C.L.; Close, D.A.; Moss, C.E.

    1986-09-01

    The energetic gamma-ray spectra from the fission products of photofission have been investigated to determine whether photofission can identify heavily shielded fissionable material. Target samples of natural thorium, 93% enriched /sup 235/U, natural uranium, and 93% enriched /sup 239/Pu were irradiated with bremsstrahlung gamma rays produced by 10-MeV electrons from a small linear accelerator. The gamma-ray spectra for each of the four isotopes studied reveals a distinctive intensity distribution. For example, the intensity ratio of the pair of gamma rays at 1436 keV (/sup 138/Cs) and 1428 keV (/sup 94/Sr) is 1.9 for /sup 235/U, 2.4 for /sup 238/U, 1.7 for /sup 232/Th and 1.4 for /sup 239/Pu. 6 refs., 2 figs., 1 tab.

  17. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia.

    PubMed

    Cagno, S; Hellemans, K; Lind, O C; Skipperud, L; Janssens, K; Salbu, B

    2014-02-01

    Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples. PMID:24424783

  18. An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry.

    PubMed

    Wang, T K; Peir, J J

    2000-01-01

    The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio. PMID:10670930

  19. Temporal record of Pu isotopes in inter-tidal sediments from the northeastern Irish Sea.

    PubMed

    Lindahl, Patric; Worsfold, Paul; Keith-Roach, Miranda; Andersen, Morten B; Kershaw, Peter; Leonard, Kins; Choi, Min-Seok; Boust, Dominique; Lesueur, Patrick

    2011-11-01

    A depth profile of (239)Pu and (240)Pu specific activities and isotope ratios was determined in an inter-tidal sediment core from the Esk Estuary in the northeastern Irish Sea. The study site has been impacted with plutonium through routine radionuclide discharges from the Sellafield nuclear reprocessing plant in Cumbria, NW England. A pronounced sub-surface maximum of ~10 k Bq kg(-1) was observed for (239+240)Pu, corresponding to the peak in Pu discharge from Sellafield in 1973, with a decreasing trend with depth down to ~0.04 k Bq kg(-1) in the deeper layers. The depth profile of (239+240)Pu specific activities together with results from gamma-ray spectrometry for (137)Cs and (241)Am was compared with reported releases from the Sellafield plant in order to estimate a reliable sediment chronology. The upper layers (1992 onwards) showed higher (239+240)Pu specific activities than would be expected from the direct input of annual Sellafield discharges, indicating that the main input of Pu is from the time-integrated contaminated mud patch of the northeastern Irish Sea. The (240)Pu/(239)Pu atom ratios ranged from ~0.03 in the deepest layers to >0.20 in the sub-surface layers with an activity-weighted average of 0.181. The decreasing (240)Pu/(239)Pu atom ratio with depth reflects the changing nature of operations at the Sellafield plant from weapons-grade Pu production to reprocessing spent nuclear fuel with higher burn-up times in the late 1950s. In addition, recent annual (240)Pu/(239)Pu atom ratios in winkles collected during 2003-2008 from three stations along the Cumbrian coastline showed no significant spatial or temporal differences with an overall average of 0.204, which supports the hypothesis of diluted Pu input from the contaminated mud patch. PMID:21911246

  20. Experiments on the synthesis of superheavy nuclei 284Fl and 285Fl in the Pu,240239+48Ca reactions

    NASA Astrophysics Data System (ADS)

    Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu. Ts.; Rykaczewski, K. P.; Abdullin, F. Sh.; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu. S.; Voinov, A. A.; Subbotin, V. G.; Sukhov, A. M.; Sabel'nikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2015-09-01

    Irradiations of 239Pu and 240Pu targets with 48Ca beams aimed at the synthesis of Z =114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284Fl was produced for the first time in the 240Pu+48Ca (250 MeV) and 239Pu+48Ca (245 MeV) reactions. The cross section of the 239Pu(48Ca,3 n )284Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3 n and 4 n channels measured in the 244Pu+48Ca reaction. In the 240Pu+48Ca experiment, performed at 245 MeV in order to maximize the 3 n -evaporation channel, three decay chains of 285Fl were detected. The α -decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240Pu target with a 250 MeV 48Ca beam to 284Fl decay is presented and discussed. The cross sections at both 48Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N =184 .

  1. Radionuclide concentrations in soils and vegetation at radioactive-waste disposal Area G during the 1996 growing season. Progress report

    SciTech Connect

    Fresquez, P.R.; Vold, E.L.; Naranjo, L. Jr.

    1997-07-01

    Soil and overstory and understory vegetation (washed and unwashed) collected at eight locations within and around Area G--a low-level radioactive solid-waste disposal facility at Los Alamos National laboratory--were analyzed for {sup 3}H, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, {sup 137}Cs, {sup 234}U, {sup 235}U, {sup 238}U, {sup tot}U, {sup 228}Ac, {sup 214}Bi, {sup 60}Co, {sup 40}K, {sup 54}Mn, {sup 22}Na, {sup 214}Pb, and {sup 208}Tl. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in soil and vegetation were determined. In general, most radionuclide concentrations, with the exception of {sup 3}H and {sup 239}Pu, in soils and washed and unwashed overstory and understory vegetation collected from within and around Area G were within upper limit background concentrations. Tritium was detected as high as 14,744 pCi mL{sup {minus}1} in understory vegetation collected from transuranic (TRU) waste pad {number_sign}4, and the TRU waste pad area contained the highest levels of {sup 239}Pu in soils and in understory vegetation as compared to other areas at Area G.

  2. Radionuclide concentrations in/on vegetation at radioactive-waste disposal Area G during the 1995 growing season. Progress report

    SciTech Connect

    Fresquez, P.R.; Vold, E.L.; Naranjo, L. Jr.

    1996-03-01

    Overstory (pinon pine) and understory (grass and forb) vegetation were collected within and around selected points at Area G--a low- level radioactive solid-waste disposal facility at Los Alamos National Laboratory--for the analysis of tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238}Pu and {sup 239}Pu), cesium ({sup 137}Cs), and total uranium. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in/on vegetation were determined. In general, most (unwashed) vegetation collected within and around Area G contained {sup 3}H, uranium, {sup 238}Pu, and {sup 239}Pu in higher concentrations than vegetation collected from background areas. Tritium, in particular, was detected as high as 7300 pCi mL{sup -1} in understory vegetation collected from the west side of the transuranic (TRU) pads. The south and west ends of the tritium shaft field also contained elevated levels of {sup 3}H in overstory, and especially in understory vegetation, as compared to background; this suggests that {sup 3}H may be migrating from this waste repository through surface and subsurface pathways. Also, understory vegetation collected north of the TRU pads (adjacent to the fence line of Area G) contained the highest values of {sup 238}Pu and {sup 239}Pu as compared to background, and may be a result of surface holding, storage, and/or disposal activities.

  3. Release of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant accident to the marine environment was negligible.

    PubMed

    Bu, Wenting; Fukuda, Miho; Zheng, Jian; Aono, Tatsuo; Ishimaru, Takashi; Kanda, Jota; Yang, Guosheng; Tagami, Keiko; Uchida, Shigeo; Guo, Qiuju; Yamada, Masatoshi

    2014-08-19

    Atmospheric deposition of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been observed in the terrestrial environment around the FDNPP site; however, their deposition in the marine environment has not been studied. The possible contamination of Pu in the marine environment has attracted great scientific and public concern. To fully understand this possible contamination of Pu isotopes from the FDNPP accident to the marine environment, we collected marine sediment core samples within the 30 km zone around the FDNPP site in the western North Pacific about two years after the accident. Pu isotopes ((239)Pu, (240)Pu, and (241)Pu) and radiocesium isotopes ((134)Cs and (137)Cs) in the samples were determined. The high activities of radiocesium and the (134)Cs/(137)Cs activity ratios with values around 1 (decay corrected to 15 March 2011) suggested that these samples were contaminated by the FDNPP accident-released radionuclides. However, the activities of (239+240)Pu and (241)Pu were low compared with the background level before the FDNPP accident. The Pu atom ratios ((240)Pu/(239)Pu and (241)Pu/(239)Pu) suggested that global fallout and the pacific proving ground (PPG) close-in fallout are the main sources for Pu contamination in the marine sediments. As Pu isotopes are particle-reactive and they can be easily incorporated with the marine sediments, we concluded that the release of Pu isotopes from the FDNPP accident to the marine environment was negligible. PMID:25050458

  4. Rapid determination of alpha emitters using Actinide resin.

    PubMed

    Navarro, N; Rodriguez, L; Alvarez, A; Sancho, C

    2004-01-01

    The European Commission has recently published the recommended radiological protection criteria for the clearance of building and building rubble from the dismantling of nuclear installations. Radionuclide specific clearance levels for actinides are very low (between 0.1 and 1 Bq g(-1)). The prevalence of natural radionuclides in rubble materials makes the verification of these levels by direct alpha counting impossible. The capability of Actinide resin (Eichrom Industries, Inc.) for extracting plutonium and americium from rubble samples has been tested in this work. Besides a strong affinity for actinides in the tri, tetra and hexavalent oxidation states, this extraction chromatographic resin presents an easy recovery of absorbed radionuclides. The retention capability was evaluated on rubble samples spiked with certified radionuclide standards (239Pu and 241Am). Samples were leached with nitric acid, passed through a chromatographic column containing the resin and the elution fraction was measured by LSC. Actinide retention varies from 60% to 80%. Based on these results, a rapid method for the verification of clearance levels for actinides in rubble samples is proposed. PMID:15177360

  5. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 7B (MACROBATCH 9)

    SciTech Connect

    Crawford, C. L.; Diprete, D. P.

    2014-05-01

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu- 242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to

  6. Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

    SciTech Connect

    Crawford, C. L.; DiPrete, D. P.

    2013-08-22

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to

  7. DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 6 (MACROBATCH 7)

    SciTech Connect

    Bannochie, C.; Diprete, D.

    2011-06-01

    The Waste Acceptance Product Specifications (WAPS) 1.2 require that 'The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115'. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production through the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 5 (SB5) with H-Canyon Np transfers completed after the start of processing SB5, and Sludge Batch 6 (SB6) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 7 (MB7). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the

  8. Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples. [Patent application

    DOEpatents

    Caldwell, J.T.; Kunz, W.E.; Cates, M.R.; Franks, L.A.

    1982-07-07

    Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fission are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for /sup 239/Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

  9. Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples

    DOEpatents

    Caldwell, John T.; Kunz, Walter E.; Cates, Michael R.; Franks, Larry A.

    1985-01-01

    Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for .sup.239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

  10. Resonance ionization mass spectroscopy for trace analysis of plutonium

    NASA Astrophysics Data System (ADS)

    Erdmann, N.; Albus, F.; Deiβenberger, R.; Eberhardt, K.; Funk, H.; Hasse, H.-U.; Herrmann, G.; Huber, G.; Kluge, H.-J.; Köhler, S.; Nunnemann, M.; Passler, G.; Trautmann, N.; Urban, F.-J.

    1995-04-01

    Trace amounts of plutonium are determined by means of resonance ionization mass spectroscopy (RIMS). Plutonium atoms evaporated from a heated filament are ionized via a three-step exciation leading to an autoionizing state. The ions are mass-selectively detected with a time-of-flight (TOF) mass spectrometer. Several types of filaments have been tested with respect to atomic yield after evaporation and reproducibility. The best results have been obtained using tantalum as backing and titanium as covering. An overall detection efficiency of 1ṡ10-5 could be determined with such filaments yielding a detection limit of 2ṡ106 atoms of 239Pu.

  11. Radionuclides and heavy metals in rainbow trout from Tsichomo, Nana Ka, Wen Povi, and Pin De Lakes in Santa Clara Canyon

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Naranjo, L. Jr.

    1998-04-01

    Radionuclide ({sup 3}H, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium) and heavy metal (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and TI) concentrations were determined in rainbow trout collected from Tsichomo, Nana Ka, Wen Povi, and Pin De lakes in Santa Clara Canyon in 1997. Most radionuclide and heavy metal concentrations in fish collected from these four lakes were within or just above upper limit background concentrations (Abiquiu reservoir), and as a group were statistically (p < 0.05) similar in most parameters to background.

  12. Determining Sources and Transport of Nuclear Contamination in Hudson River Sediments with Plutonium, Neptunium, and Cesium isotope ratios

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Chillrud, S. N.; Chaky, D. A.; Simpson, H. J.; McHugh, C. M.; Shuster, E. L.; Bopp, R. F.

    2004-12-01

    Different sources of radioactive contamination contain characteristic and identifiable isotopic signatures, which can be used to study sediment transport. We focus on Pu-239, Pu-240, Np-237 and Cs-137, which are strongly bound to fine grained sediments. The Hudson River drainage basin has received contamination from at least three separate sources: 1) global fallout from atmospheric testing of nuclear weapons, which contributed Pu, Np and Cs; 2) contamination resulting from reactor releases at the Indian Point Nuclear Power Plant (IPNPP) located on the Hudson River Estuary ˜70km north of New York Harbor, where records document releases of Cs-137; 3) contamination resulting from activities at the Knolls Atomic Power Laboratory (KAPL) located on the Mohawk River, where incomplete records document releases of Cs-137 but no mention is made of Pu or Np. Here we report measurements of Pu isotopes, Np-237 and Cs-137 for a series of sediment cores collected from various locations within the drainage basin: 1) Mohawk River downstream of KAPL, 2) Hudson River upstream of its confluence with the Mohawk River, and 3) lower Hudson River at a location in close proximity to IPNPP. In addition, we present data from selected samples from two other lower Hudson River locations: One site located ˜30km downstream of IPNPP and another ˜30km upstream of IPNPP. By comparing the isotopic ratios Pu-240/Pu-239, Np-237/Pu-239, and Cs-137/Pu-239, measured in fluvial sediments to mean global fallout values, it is possible to identify and resolve different sources of non-fallout contamination. To date, isotopic data for sediments indicate non-fallout sources of Pu-239, Pu-240, and Cs-137; Np-237, however, appears to originate from global fallout only. Mohawk River sediments downstream of KAPL exhibit enrichments in Pu-239, Pu-240, and Cs-137 that are 7 to 20 times higher than levels expected from global fallout as indicated from Np-237. The elevated levels, non-fallout isotopic signatures

  13. Fracture occurrence from radionuclides in the skeleton

    SciTech Connect

    Lloyd, R.D.; Taylor, G.N.; Miller, S.C.

    2000-06-01

    Because skeletal fractures were an important finding among persons contaminated with {sup 226}Ra, experience with fractures among dogs in the colony was summarized to determine the projected significance for persons contaminated with bone-seeking radionuclides. Comparison by Fisher's Exact Test of lifetime fracture occurrence in the skeletons of beagles injected as young adults suggested that for animals given {sup 226}Ra, {sup 228}Ra, {sup 228}Th, or {sup 239}Pu citrate, there was probably an excess over controls in fractures of the ribs, leg bones, spinous processes, and pelvis (os coxae) plus the mandible for dogs given {sup 226}Ra and the scapulae for dogs given {sup 228}Ra or 228 Th. Regression analysis indicated that significantly elevated fracture occurrence was especially notable at the higher radiation doses, at about 50 Gy average skeletal dose for {sup 239}Pu, 140 Gy for {sup 226}Ra, about 40 Gy for {sup 228}Ra, and more than 15 Gy for {sup 228}Th. The average number of fractures per dog was significantly elevated over that noted in controls for the highest radiation doses of {sup 239}Pu and {sup 226}Ra and for the higher doses of {sup 228}Ra and {sup 228}Th. For those dogs given {sup 90}Sr citrate, there was virtually no important difference from control beagles not given radionuclides, even at group mean cumulative skeletal radiation doses up to 101 Gy. Because of a large proportion of dogs with fractures that died with bone malignancy (even at dosage levels lower than those exhibiting an excess average number of fractures per dog), they conclude that fracture would not be an important endpoint at lower levels of plutonium contamination in humans such as would be expected to occur from occupational or environmental exposure.

  14. Sources and migration of plutonium in groundwater at the Savannah River site.

    PubMed

    Dai, Minhan; Kelley, James M; Buesseler, Ken O

    2002-09-01

    The isotopic composition, size distribution, and redox speciation of plutonium (Pu) in the groundwater in the vicinity of the F-area seepage basins at the U.S. Department of Energy Savannah River Site (SRS) were examined. A low 240Pu/239Pu ratio in the upstream control well signifies a Pu source otherthan global fallout and indicates reactor-produced Pu. Elevated 240Pu/239Pu atom ratios downstream from the seepage basins are due to the decay of transplutonium isotopes, mainly 244Cm to 240Pu, which were generated at the SRS. Evidence suggests that the migration of basin-released Pu isotopes is minor. Rather, it is the transplutonium isotopes that migrate preferentially downstream and in the process decay to yield progeny Pu isotopes. Size fractionation studies with cross-flow ultrafiltration show that <4% of the 239Pu or 240Pu is found in the colloidal fraction, a finding that is consistent with the higher Pu oxidation states observed in the SRS groundwater. The observation of a low abundance of colloid-associated Pu in SRS groundwater cannot be extrapolated to all sites, but is in contrast to the conclusions of prior groundwater Pu studies at the SRS and elsewhere. This work is unique in its application of a novel combination of sampling and processing protocols as well as its use of thermal ionization mass spectrometry for the detection of Pu isotopes. This allows quantification of the Pu source terms and better determination of the ambient Pu size and redox speciation representative of in situ conditions. PMID:12322739

  15. Comparative food-chain behavior and distribution of actinide elements in and around a contaminated fresh-water pond

    SciTech Connect

    Garten, C.T. Jr.; Trabalka, J.R.; Bogle, M.A.

    1981-01-01

    The bioaccumulation of /sup 233/ /sup 234/U, /sup 238/U, /sup 238/Pu, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 244/Cm in both native and introduced biota was studied at Pond 3513, a former low-level radioactive waste settling basin at Oak Ridge National Laboratory. This system, which was decommissioned in 1976 after more than 30 years use, contains approximately 5 Ci of /sup 239/ /sup 240/Pu; inventories of other actinide isotopes are considerably less. Significantly higher concentrations of actinides in fish that were allowed access to sediments indicated that sedimentary particulates may be the primary source of transuranics to biota in shallow fresh-water ecosystems. Our study determined habitat, in particular the degree of association of an organism with the sediment-water interface, to be the primary factor in controlling transuranic concentrations in aquatic biota. In most of the biological samples analyzed, excluding samples suspected of being contaminated by sediment, /sup 241/Am//sup 239/Pu, /sup 244/Cm//sup 239/Pu, and /sup 238/U//sup 239/Pu ratios were greater than the respective ratio in sediment while /sup 233/ /sup 234/U//sup 238/U, and /sup 239/ /sup 240/Pu//sup 238/Pu ratios were not different from the respective ratios in sediment. The relative uptake of actinides from contaminated sediment by aquatic and terrestrial biota at this site was U > Cm greater than or equal to Am > Pu. The relative extractability of actinides from shoreline sediment was U > Cm approx. = Am > Pu; we also observed the same relative ranking for sediment-water exchange in situ. Concentrations of transuranics in water, terrestrial vegetation, and vertebrate carcasses were less than 10% of the recommended public exposure maximum permissible concentration (MPC) of the ICRP.

  16. Distributions of Pu isotopes in seawater and bottom sediments in the coast of the Japanese archipelago before and soon after the Fukushima Dai-ichi Nuclear Power Station accident.

    PubMed

    Oikawa, Shinji; Watabe, Teruhisa; Takata, Hyoe

    2015-04-01

    A radioactivity measurement survey was carried out from 24 April 2008 to 3 June 2011 to determine the levels of plutonium isotopes and (240)Pu/(239)Pu atom ratios in the marine environments off the sites of commercial nuclear power stations around the Japanese islands; the sampling period extended to two months after the Fukushima Dai-ichi Nuclear Power Station accident. In our previous study (Oikawa et al., 2015), data on Pu isotopes and (241)Am in sediments have already been reported. In this study, we report those on Pu isotopes in seawater as well as sediments, and the characteristics of sediments in addition (e.g., ignition loss and biogenic opals). Concentrations of (239+240)Pu in seawater and bottom sediments remained nearly constant at all sampling locations during the survey period. In addition, no regional differences were observed in the (239+240)Pu concentrations in surface waters. Higher (239+240)Pu concentrations were found in bottom waters at deeper sampling locations, but the (240)Pu/(239)Pu atom ratios were nearly constant regardless of the water depth. Higher (239+240)Pu concentrations were also found in bottom sediments at deeper sampling locations, but vice versa for (240)Pu/(239)Pu atom ratios as reported in the previous report. The sediments samples from deeper locations showed the higher percentage of ignition loss as well as the higher content of biogenic opal. There was likely to be some driving force participating in the transfer of Pu isotopes associated with biogenic substances to the deeper seabed. The present survey showed that the accident at the Fukushima Dai-ichi Nuclear Power Station did not contribute much to the inventory of Pu isotopes in the adjacent sea area. PMID:25659922

  17. Anomalous plutonium isotopic ratios in sediments of Lake Qinghai from the Qinghai-Tibetan Plateau, China.

    PubMed

    Wu, Fengchang; Zheng, Jian; Liao, Haiqing; Yamada, Masatoshi; Wan, Guojiang

    2011-11-01

    The vertical profiles of (239+240)Pu and (137)Cs activities and (240)Pu/(239)Pu isotopic ratios are determined for three sediment cores of Lake Qinghai from the Qinghai-Tibetan Plateau, China, and compared with those in sediments of another three lakes (Lakes Bosten, Sugan, and Shuangta), the only existing ones closest to Lop Nor area, China's nuclear weapons test site in the northwestern part of the country. The mean inventory of 47.7 ± 18.7 MBq km(-2) for (239+240)Pu activity in Lake Qinghai is comparable to the average value of global fallout expected at the same latitude, yet the mean inventory of 1112.0 ± 78.0 MBq km(-2) for (137)Cs is slightly lower than that of global fallout. Anomalously low (240)Pu/(239)Pu isotopic ratios (0.038-0.125) were found in the 3-6.5 cm deep sediment layers, indicating the trace Pu input from early nuclear weapons research activities at Atomic City in the lake's watershed during the 1950-60s. Model calculation indicated that the Pu input accounted for approximately 5-16% of the total Pu inventory. The observation of low (240)Pu/(239)Pu ratio in the deep sediment layer provided a new time marker for recent sediment dating in the lake and around the area. The results are of great significance to the further understanding of sources, records, and environmental impacts of global and regional nuclear activities in the environment and provide important chronological information for further studies on the water eutrophication process and climatic change, and reconstruction of pollution history of organic contaminants and heavy metals in the watershed of Lake Qinghai. PMID:21950768

  18. Analysis of 236U and plutonium isotopes, 239,240Pu, on the 1 MV AMS system at the Centro Nacional de Aceleradores, as a potential tool in oceanography

    NASA Astrophysics Data System (ADS)

    Chamizo, Elena; López-Lora, Mercedes; Villa, María; Casacuberta, Núria; López-Gutiérrez, José María; Pham, Mai Khanh

    2015-10-01

    The performance of the 1 MV AMS system at the CNA (Centro Nacional de Aceleradores, Seville, Spain) for 236U and 239,240Pu measurements has been extensively investigated. A very promising 236U/238U abundance sensitivity of about 3 × 10-11 has been recently achieved, and background figures for 239Pu of about 106 atoms were reported in the past. These promising results lead to the use of conventional low energy AMS systems for the analysis of 236U and 239Pu and its further application in environmental studies. First 236U results obtained on our AMS system for marine samples (sediments and water) are presented here. Results of two new IAEA reference materials (IAEA-410 and IAEA-412, marine sediments from Pacific Ocean) are reported. The obtained 236U/239Pu atom ratios, of 0.12 and 0.022, respectively, show a dependency with the contamination source (i.e. local fallout from the US tests performed at the Bikini Atoll and general fallout). The results obtained for a third IAEA reference material (IAEA-381, seawater from the Irish Sea), are also presented. In the following, the uranium and plutonium isotopic compositions obtained on a set of 5 intercomparison seawater samples from the Arctic Ocean provided by the ETH Zürich are discussed. By comparing them with the obtained results on the 600 kV AMS facility Tandy at the ETH Zürich, we demonstrate the solidity of the CNA technique for 236U/238U determinations at, at least, 7 × 10-10 level. Finally, these results are discussed in their environmental context.

  19. Initial Report for the Aquifer Background Study: Summary of Uranium and Plutonium Data from INEEL Groundwater Samples

    SciTech Connect

    Robert C. Roback; Don L. Koeppen

    2003-06-01

    As part of the “Aquifer Background Study,” Los Alamos National Laboratory (LANL) under contract with the Idaho National Engineering and Environmental Laboratory (INEEL) has undertaken a study to determine uranium and plutonium abundances and isotopic composition in groundwater samples collected at the INEEL. To date, four samples have been analyzed for uranium and plutonium and an additional nine samples have been analyzed for uranium. It is expected that several more samples will be analyzed for this study. This report summarizes the results from this initial set of samples. Of the 13 samples analyzed for uranium, four samples have 238U/235U ratios that differ from the natural value of 137.88. These four samples and two additional samples also contain 236U at 3-sigma level above detection limits. The presence of 236U and the non-natural 238U/235U ratios unequivocally indicate the presence of anthropic uranium in four of the samples. A small component of anthropic uranium is also present in two additional samples with positive 236U detection but natural 238U/235U isotope ratios. Two of the samples with anthropic uranium, as well as two samples with no detectable anthropic uranium were analyzed for plutonium. No plutonium was detected in these four samples at detection limits of approximately 5E7 239Pu atoms for three of the samples and approximately 1E8 239Pu atoms for the forth sample. These detection limits correspond to (239+240)Pu activity ratios (assuming a 240Pu/239Pu atom ratio of 0.18) of 0.002 and 0.004 pCi/L respectively.

  20. Investigation of storage-phosphor autoradiography for the rapid quantitative screening of air filters for emergency response purposes

    NASA Astrophysics Data System (ADS)

    Gallardo, Athena Marie

    either 241Am or 239Pu as well as air filters doped with beta and alpha emitting nuclides were imaged and activities were determined by comparing the image to the activity calibration curve.

  1. Multi-Collector Inductively Coupled Plasma Mass Spectrometer – Operational Performance Report

    SciTech Connect

    Matthew Watrous; Anthony Appelhans; Robert Hague; John Olson; Tracy Houghton

    2013-06-01

    The INL made an assessment of the commercially available inductively coupled plasma mass spectrometers (ICPMS) for actinide analysis; emphasizing low detection limits for plutonium. INL scientists subsequently determined if plutonium was present on a swipe, at a 10 million atom decision level. This report describes the evaluation of ICPMS instruments and the operational testing of a new process for the dissolution, separation and analysis via ICPMS of swipes for plutonium and uranium. The swipe dissolution, plutonium and uranium isolation, separation and purification are wet chemistry methods following established procedures. The ICPMS is a commercially available multi-collector magnetic sector mass spectrometer that utilizes five ion counting detectors operating simultaneously. The instrument includes a sample introduction system allowing for sample volumes of < 1 mL to be reproducibly injected into the instrument with minimal waste of the sample solution, while maximizing the useable signal. The performance of the instrument was measured using SRM 996 (244Pu spike) at concentrations of 12 parts per quadrillion (ppq, fg/mL) and with SRM 4350B Columbia River Sediment samples spiked onto swipes at the 10 million atom level. The measured limit of detection (LOD, defined as 3s) for 239Pu is 310,000 atoms based upon the instrument blank data. The limit of quantification (LOQ defined as 10 s) for 239Pu is 105,000 atoms. The measured limit of detection for 239Pu from the SRM 4350B spiked onto a swipe was 2.7 million atoms with the limit of quantification being 9.0 million atoms.

  2. Determining the Radiation Damage Effect on Glovebox Glove Material.

    SciTech Connect

    Cournoyer, M. E.; Balkey, J. J.; Andrade, R.M.

    2005-01-01

    The Nuclear Material Technology (NMT) Division has the largest inventory of glove box gloves at Los Alamos National Laboratory. The minimization of unplanned breaches in the glovebox, e.g., glove failures, is a primary concern in the daily operations in NMT Division facilities, including the Plutonium Facility (PF-4) at TA-55 and Chemical and Metallurgy Research (CMR) Facility. Glovebox gloves in these facilities are exposed to elevated temperatures and exceptionally aggressive radiation environments (particulate {sup 239}Pu and {sup 238}Pu). Predictive models are needed to estimate glovebox glove service lifetimes, i.e. change-out intervals. Towards this aim aging studies have been initiated that correlate changes in mechanical (physical) properties with degradation chemistry. This present work derives glovebox glove change intervals based on previously reported mechanical data of thermally aged hypalon glove samples. Specifications for 30 mil tri-layered hypalon/lead glovebox gloves (TLH) and 15 mil hypalon gloves (HYP) have already been established. The relevant mechanical properties are shown on Table 1. Tensile strength is defined as the maximum load applied in breaking a tensile test piece divided by the original cross-sectional area of the test piece (Also termed maximum stress and ultimate tensile stress). Ultimate elongation is the elongation at time of rupture (Also termed maximum strain). The specification for the tensile test and ultimate elongation are the minimum acceptable values. In addition, the ultimate elongation must not vary 20% from the original value. In order to establish a service lifetimes for glovebox gloves in a thermal environment, the mechanical properties of glovebox glove materials were studied.

  3. Spatially resolved analysis of plutonium isotopic signatures in environmental particle samples by laser ablation-MC-ICP-MS.

    PubMed

    Konegger-Kappel, Stefanie; Prohaska, Thomas

    2016-01-01

    Laser ablation-multi-collector-inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) was optimized and investigated with respect to its performance for determining spatially resolved Pu isotopic signatures within radioactive fuel particle clusters. Fuel particles had been emitted from the Chernobyl nuclear power plant (ChNPP) where the 1986 accident occurred and were deposited in the surrounding soil, where weathering processes caused their transformation into radioactive clusters, so-called micro-samples. The size of the investigated micro-samples, which showed surface alpha activities below 40 mBq, ranged from about 200 to 1000 μm. Direct single static point ablations allowed to identify variations of Pu isotopic signatures not only between distinct fuel particle clusters but also within individual clusters. The resolution was limited to 100 to 120 μm as a result of the applied laser ablation spot sizes and the resolving power of the nuclear track radiography methodology that was applied for particle pre-selection. The determined (242)Pu/(239)Pu and (240)Pu/(239)Pu isotope ratios showed a variation from low to high Pu isotope ratios, ranging from 0.007(2) to 0.047(8) for (242)Pu/(239)Pu and from 0.183(13) to 0.577(40) for (240)Pu/(239)Pu. In contrast to other studies, the applied methodology allowed for the first time to display the Pu isotopic distribution in the Chernobyl fallout, which reflects the differences in the spent fuel composition over the reactor core. The measured Pu isotopic signatures are in good agreement with the expected Pu isotopic composition distribution that is typical for a RBMK-1000 reactor, indicating that the analyzed samples are originating from the ill-fated Chernobyl reactor. The average Pu isotope ratios [(240)Pu/(239)Pu = 0.388(86), (242)Pu/(239)Pu = 0.028(11)] that were calculated from all investigated samples (n = 48) correspond well to previously published results of Pu analyses in contaminated samples from

  4. Determination of the Sensitivity of the Antineutrino Probe for Reactor Core Monitoring

    SciTech Connect

    Cormon, S.; Fallot, M. Bui, V.-M.; Cucoanes, A.; Estienne, M.; Lenoir, M.; Onillon, A.; Shiba, T.; Yermia, F.; Zakari-Issoufou, A.-A.

    2014-06-15

    This paper presents a feasibility study of the use of the detection of reactor-antineutrinos (ν{sup ¯}{sub e}) for non proliferation purpose. To proceed, we have started to study different reactor designs with our simulation tools. We use a package called MCNP Utility for Reactor Evolution (MURE), initially developed by CNRS/IN2P3 labs to study Generation IV reactors. The MURE package has been coupled to fission product beta decay nuclear databases for studying reactor antineutrino emission. This method is the only one able to predict the antineutrino emission from future reactor cores, which don't use the thermal fission of {sup 235}U, {sup 239}Pu and {sup 241}Pu. It is also the only way to include off-equilibrium effects, due to neutron captures and time evolution of the fission product concentrations during a reactor cycle. We will present here the first predictions of antineutrino energy spectra from innovative reactor designs (Generation IV reactors). We will then discuss a summary of our results of non-proliferation scenarios involving the latter reactor designs, taking into account reactor physics constraints.

  5. RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

    SciTech Connect

    Maxwell, S.; Jones, V.

    2009-05-27

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead

  6. U, Pu, and Am nuclear signatures of the Thule hydrogen bomb debris.

    PubMed

    Eriksson, Mats; Lindahl, Patric; Roos, Per; Dahlgaard, Henning; Holm, Elis

    2008-07-01

    This study concerns an arctic marine environment that was contaminated by actinide elements after a nuclear accident in 1968, the so-called Thule accident In this study we have analyzed five isolated hot particles as well as sediment samples containing particles from the weapon material for the determination of the nuclear fingerprint of the accident. We report that the fissile material in the hydrogen weapons involved in the Thule accident was a mixture of highly enriched uranium and weapon-grade plutonium and that the main fissile material was 235U (about 4 times more than the mass of 239Pu). In the five hot particles examined, the measured uranium atomic ratio was 235U/238U = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: 24Pu/239Pu = 0.0551 +/- 0.0008 (atom ratio), 238Pu/239+240Pu = 0.0161 +/- 0.0005 (activity ratio), 241Pu/239+240Pu = 0.87 +/- 0.12 (activity ratio), and 241Am/ 239+240Pu = 0.169 +/- 0.005 (activity ratio) (reference date 2001-10-01). From the activity ratios of 241Pu/241Am, we estimated the time of production of this weapon material to be from the late 1950s to the early 1960s. The results from reanalyzed bulk sediment samples showed the presence of more than one Pu source involved in the accident, confirming earlier studies. The 238Pu/239+240PU activity ratio and the 240Pu/ 239Pu atomic ratio were divided into at least two Pu-isotopic ratio groups. For both Pu-isotopic ratios, one ratio group had identical ratios as the five hot particles described above and for the other groups the Pu isotopic ratios were lower (238Pu/ 239+240PU activity ratio approximately 0.01 and the 240Pu/P239Pu atomic ratio 0.03). On the studied particles we observed that the U/Pu ratio decreased as a function of the time these particles were present in the sediment. We hypothesis that the decrease in the ratio is due to a preferential leaching of U relative to Pu from the particle matrix. PMID:18677996

  7. Stochastic determination of matrix determinants.

    PubMed

    Dorn, Sebastian; Ensslin, Torsten A

    2015-07-01

    Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes, linear operations-matrices-acting on the data are often not accessible directly but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. While efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrix-vector multiplications, are well known and frequently used in signal inference, there is no stochastic estimate for its determinant. We introduce a probing method for the logarithm of a determinant of a linear operator. Our method rests upon a reformulation of the log-determinant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables large-size applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination. PMID:26274302

  8. Stochastic determination of matrix determinants

    NASA Astrophysics Data System (ADS)

    Dorn, Sebastian; Enßlin, Torsten A.

    2015-07-01

    Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes, linear operations—matrices—acting on the data are often not accessible directly but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. While efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrix-vector multiplications, are well known and frequently used in signal inference, there is no stochastic estimate for its determinant. We introduce a probing method for the logarithm of a determinant of a linear operator. Our method rests upon a reformulation of the log-determinant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables large-size applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination.

  9. UPWARD MOVEMENT OF PLUTONIUM TO SURFACE SEDIMENTS DURING AN 11-YEAR FIELD STUDY

    SciTech Connect

    Kaplan, D.; Beals, D.; Cadieux, J.; Halverson, J.

    2010-01-25

    An 11-y lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The {sup 240}Pu/{sup 239}Pu and {sup 242}Pu/{sup 239}Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments.

  10. QUALIFICATION OF THE SAVANNAH RIVER SITE 252CF SHUFFLER FOR RECEIPT VERIFICATION MEASUREMENTS OF MIXED U-PU OXIDES STORED IN 9975 SHIPPING CONTAINERS

    SciTech Connect

    Dubose, F.

    2011-05-26

    To extend their ability to perform accountability and verification measurements of {sup 235}U in a U-Pu oxide matrix, the K-Area Material Storage facility commissioned the development and construction of a Passive/Active {sup 252}Cf Shuffler. A series of {sup 252}Cf, PuO{sub 2}, and U-Pu oxide standards, in addition to a single U{sub 3}O{sub 8} standard, were measured to characterize and calibrate the shuffler. Accompanying these measurements were simulations using MCNP5/MCNPX, aimed at isolating the neutron countrate contributions for each of the isotopes present. Two calibration methods for determining the {sup 235}U content in mixed UPu oxide were then developed, yielding comparable results. The first determines the {sup 235}U mass by estimating the {sup 239}Pu/{sup 235}U ratio-dependent contributions from the primary delayed neutron contributors. The second defines an average linear response based on the {sup 235}U and {sup 239}Pu mass contents. In each case, it was observed that self-shielding due to {sup 235}U mass has a large influence on the observed rates, requiring bounds on the applicable limits of each calibration method.

  11. 237Np in hemp-palm leaves of Bontenchiku for fishing gear used by the Fifth Fukuryu-Maru: 40 years after "Bravo".

    PubMed

    Yamamoto, M; Ishiguro, T; Tazaki, K; Komura, K; Ueno, K

    1996-05-01

    The alpha radioactive components in the Hemp-palm of Bontenchiku were determined with emphasis on the measurement low-level 237Np by alpha-ray spectrometry after chemical separation. Bontenchiku is a kind of fishing gear for long-line fishing used by the Fifth Fukuryu-Maru (Lucky Dragon). This gear was exposed to fallout from the second thermonuclear test explosion (Bravo) at Bikini Atoll in March 1954. The 237Np content in the Bontenchiku sample was determined to be 11.5 +/- 0.8 mBq g(-1), with an activity ratio of 237Np:239,240Pu and an atom ratio of 237Np:239Pu estimated to be (2.2 +/- 0.2) x 10(-3) and 0.42 +/- 0.04, respectively. The data showed the existence of a chain reaction of 238U and its ratio to be 237Np:239Pu, as well as the presence of 237U at the time of fallout from Bravo event in March 1954. PMID:8690589

  12. Measurement of Neutron-Induced, Angular-Momentum-Dependent Fission Probabilities Direct Reactions

    NASA Astrophysics Data System (ADS)

    Koglin, Johnathon; Jovanovic, Igor; Burke, Jason; Casperson, Robert

    2015-04-01

    The surrogate method has previously been used to successfully measure (n , f) cross sections of a variety of difficult to produce actinide isotopes. These measurements are inaccurate at excitation energies below 1.5 MeV where the distribution of angular momentum states populated in the compound nucleus created by neutron absorption significantly differs from that arising from direct reactions. A method to measure the fission probability of individual angular momentum states arising from 239 Pu(d , pf) and 239 Pu(α ,α' f) reactions has been developed. This method consists on charged particle detectors with 40 keV FWHM resolution at 13 angles up and downstream of the beam. An array of photovoltaic (solar) cells is used to measure the angular distribution of fission fragments with high angular resolution. This distribution uniquely identifies the populated angular momentum states. These are fit to expected distributions to determine the contribution of each state. The charged particle and fission matrix obtained from these measurements determines fission probabilities of specific angular momentum states in the transition nucleus. Development of this scheme and first results will be discussed. This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number 2012-DN-130-NF0001.

  13. Upward movement of plutonium to surface sediments during an 11-year field study.

    PubMed

    Kaplan, D I; Demirkanli, D I; Molz, F J; Beals, D M; Cadieux, J R; Halverson, J E

    2010-05-01

    An 11-year lysimeter study was established to monitor the movement of Pu through vadose zone sediments. Sediment Pu concentrations as a function of depth indicated that some Pu moved upward from the buried source material. Subsequent numerical modeling suggested that the upward movement was largely the result of invading grasses taking up the Pu and translocating it upward. The objective of this study was to determine if the Pu of surface sediments originated from atmosphere fallout or from the buried lysimeter source material (weapons-grade Pu), providing additional evidence that plants were involved in the upward migration of Pu. The (240)Pu/(239)Pu and (242)Pu/(239)Pu atomic fraction ratios of the lysimeter surface sediments, as determined by Thermal Ionization Mass Spectroscopy (TIMS), were 0.063 and 0.00045, respectively; consistent with the signatures of the weapons-grade Pu. Our numerical simulations indicate that because plants create a large water flux, small concentrations over multiple years may result in a measurable accumulation of Pu on the ground surface. These results may have implications on the conceptual model for calculating risk associated with long-term stewardship and monitored natural attenuation management of Pu contaminated subsurface and surface sediments. PMID:20227801

  14. Dating of sediments from four Swiss prealpine lakes with (210)Pb determined by gamma-spectrometry: progress and problems.

    PubMed

    Putyrskaya, V; Klemt, E; Röllin, S; Astner, M; Sahli, H

    2015-07-01

    In this paper the most important problems in dating lake sediments with unsupported (210)Pb are summarized and the progress in gamma-spectrometry of the unsupported (210)Pb is discussed. The main topics of these studies concern sediment samples preparation for gamma-spectrometry, measurement techniques and data analysis, as well as understanding of accumulation and sedimentation processes in lakes. The vertical distributions of artificial ((137)Cs, (241)Am, (239)Pu) and natural radionuclides ((40)K, (210,214)Pb, (214)Bi) as well as stable trace elements (Fe, Mn, Pb) in sediment cores from four Swiss lakes were used as examples for the interpretation, inter-comparison and validation of depth-age relations established by three (210)Pb-based models (CF-CSR, CRS and SIT). The identification of turbidite layers and the influence of the turbidity flows on the accuracy of sediment dating is demonstrated. Time-dependent mass sedimentation rates in lakes Brienz, Thun, Biel and Lucerne are discussed and compared with published data. PMID:25875007

  15. Virulence Determination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews the in vitro and in vivo assays that are available for determination of pathogenic potential of Listeria monocytogenes bacteria, highlighting the value of using multiplex PCR for rapid and accurate assessment of listerial virulence....

  16. High Resolution Infrared Spectroscopy and Semi-Experimental Structures of Si2C3 and Ge2C3

    NASA Astrophysics Data System (ADS)

    Lutter, Volker; Giesen, Thomas; Gauss, Jürgen; Thorwirth, Sven

    2014-06-01

    Molecular species of group 14 elements e.g. carbon, silicon, and germanium are well suited to study cumulenic bond properties and to compare experimental results with high level quantum chemical calculations. In our recent investigation of SiC_3Si and GeC_3Ge, a high resolution laser spectrometer has been used to record rotationally resolved spectra of selected isotopologues at 5 μm. We derived semi-empirical values for Si-C and Ge-C bond distances based on spectroscopic data and corresponding zero-point vibrational corrections calculated at the CCSD(T)/cc-pVXZ level of theory (with X = T and Q). Comparison of semi-empirical structural parameters with those from quantum chemical calculations reveals very good agreement for both molecules. Relativistic effects are found negligible for SiC_3Si and small for GeC_3Ge.

  17. Preparation of a multi-isotope plutonium AMS standard and preliminary results of a first inter-lab comparison

    NASA Astrophysics Data System (ADS)

    Dittmann, B.-A.; Dunai, T. J.; Dewald, A.; Heinze, S.; Feuerstein, C.; Strub, E.; Fifield, L. K.; Froehlich, M. B.; Tims, S. G.; Wallner, A.; Christl, M.

    2015-10-01

    The motivation of this work is to establish a new multi-isotope plutonium standard for isotopic ratio measurements with accelerator mass spectrometry (AMS), since stocks of existing solutions are declining. To this end, certified reference materials (CRMs) of each of the individual isotopes 239Pu, 240Pu, 242Pu and 244Pu were obtained from JRC IRMM (Joint Research Center Institute for Reference Materials and Measurements). These certified reference materials (IRMM-081a, IRMM-083, IRMM-043 and IRMM-042a) were diluted with nitric acid and mixed to obtain a stock standard solution with an isotopic ratio of approximately 1.0:1.0:1.0:0.1 (239Pu:240Pu:242Pu:244Pu). From this stock solution, samples were prepared for measurement of the plutonium isotopic composition by AMS. These samples have been measured in a round-robin exercise between the AMS facilities at CologneAMS, at the ANU Canberra and ETH Zurich to verify the isotopic ratio and to demonstrate the reproducibility of the measurements. The results show good agreement both between the different AMS measurements and with the gravimetrically determined nominal ratios.

  18. Absolute measurement of the 242Pu neutron-capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  19. TRU waste-sampling program

    SciTech Connect

    Warren, J.L.; Zerwekh, A.

    1985-08-01

    As part of a TRU waste-sampling program, Los Alamos National Laboratory retrieved and examined 44 drums of /sup 238/Pu- and /sup 239/Pu-contaminated waste. The drums ranged in age from 8 months to 9 years. The majority of drums were tested for pressure, and gas samples withdrawn from the drums were analyzed by a mass spectrometer. Real-time radiography and visual examination were used to determine both void volumes and waste content. Drum walls were measured for deterioration, and selected drum contents were reassayed for comparison with original assays and WIPP criteria. Each drum tested at atmospheric pressure. Mass spectrometry revealed no problem with /sup 239/Pu-contaminated waste, but three 8-month-old drums of /sup 238/Pu-contaminated waste contained a potentially hazardous gas mixture. Void volumes fell within the 81 to 97% range. Measurements of drum walls showed no significant corrosion or deterioration. All reassayed contents were within WIPP waste acceptance criteria. Five of the drums opened and examined (15%) could not be certified as packaged. Three contained free liquids, one had corrosive materials, and one had too much unstabilized particulate. Eleven drums had the wrong (or not the most appropriate) waste code. In many cases, disposal volumes had been inefficiently used. 2 refs., 23 figs., 7 tabs.

  20. Characterization and testing of a {sup 238}Pu loaded ceramic waste form.

    SciTech Connect

    Johnson, S. G.

    1998-04-24

    This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with {sup 238}Pu. The purpose of this study is to determine the extent of damage, if any, that alpha decay events will play over time to the ceramic waste form under development at Argonne. The ceramic waste form is glass-bonded sodalite. The sodalite is utilized to encapsulate the fission products and transuranics which are present in a chloride salt matrix which results from a spent fuel conditioning process. {sup 238}Pu possesses approximately 250 times the specific activity of {sup 239}Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of {sup 238}Pu loaded waste forms {sup 239}Pu loaded samples were produced. Data is presented for samples produced with typical reactor grade plutonium. X-ray diffraction, scanning electron micrographs and durability test results will be presented. The ramifications for the production of the {sup 238}Pu loaded samples will be discussed.

  1. Plutonium isotopes in the terrestrial environment at the Savannah River Site, USA: a long-term study.

    PubMed

    Armstrong, Christopher R; Nuessle, Patterson R; Brant, Heather A; Hall, Gregory; Halverson, Justin E; Cadieux, James R

    2015-02-01

    This work presents the findings of a long-term plutonium (Pu) study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at the Savannah River National Laboratory (SRNL) in the A-Area. Plutonium content and isotopic abundances were measured over this time period by α particle and thermal ionization mass spectrometry (3STIMS). We detail the complete process of the sample collection, radiochemical separation, and measurement procedure specifically targeted to trace plutonium in bulk environmental samples. Total plutonium activities were determined to be not significantly above atmospheric global fallout. However, the (238)Pu/(239+240)Pu activity ratios attributed to SRS are substantially different than fallout due to past (238)Pu production on the site. The (240)Pu/(239)Pu atom ratios are reasonably consistent from year to year and are lower than fallout indicating an admixture of weapons-grade material, while the (242)Pu/(239)Pu atom ratios are higher than fallout values, again due to actinide production activities. Overall, the plutonium signatures obtained in this study reflect a distinctive mixture of weapons-grade, heat source, and higher burn-up plutonium with fallout material. This study provides a unique opportunity for developing and demonstrating a blue print for long-term low-level monitoring of trace plutonium in the environment. PMID:25535652

  2. CMR Shuffler System: Passive Mode Calibration and Certification Report

    SciTech Connect

    Frame, Katherine C.; Gomez, Cipriano D.; Salazar, William R.; Mayo, Douglas R.; Vigil, Georgiana M.; Crooks, William J.; Stange, Sy

    2012-07-20

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. As debris is removed from the vessels, material will be placed in waste drums. Far-field gamma ray assay will be used to determine when a drum is nearing a {sup 239}Pu equivalent mass of less than 200 g. The drum will then be assayed using a waste drum shuffler operated in passive mode using a neutron coincidence counting method for accountability. This report focuses on the testing and calibration of the CMR waste drum shuffler in passive mode operation. Initial testing was performed to confirm previously accepted measurement parameters. The system was then calibrated using a set of weapons grade Pu (WGPu, {sup 239}Pu > 93%) oxide standards placed inside a 55 gallon drum. The calibration data ranges from Pu mass of 0.5 g to 188.9 g. The CMR waste drum shuffler has been tested and calibrated in passive mode in preparation for safeguards accountability measurements of waste drums containing material removed from CVs for the CVD project.

  3. MATERIAL PROPERTIES OF PLUTONIUM-BEARING OXIDES STORED IN STAINLESS STEEL CONTAINERS

    SciTech Connect

    Kessinger, G.; Almond, P.; Bridges, N.; Bronikowski, M.; Crowder, M.; Duffey, J.; Livingston, R.; Mcelwee, M.; Missimer, D.; Scogin, J.; Summer, M.; Jurgensen, A.

    2010-02-01

    The destructive examination (DE) of 3013 containers after storage is part of the Surveillance and Monitoring Program based on the Department of Energy's standard for long-term storage of Pu (DOE-STD-3013). The stored, Pu-bearing materials may contain alkali halide contamination that varies from trace amounts of salt to about 50 weight percent, with smaller fractions of other compounds and oxides. These materials were characterized prior to packaging, and surveillance characterizations are conducted to determine the behavior of the materials during long term storage. The surveillance characterization results are generally in agreement with the pre-surveillance data. The predominant phases identified by X-ray diffraction are in agreement with the expected phase assemblages of the as-received materials. The measured densities are in reasonable agreement with the expected densities of materials containing the fraction of salts and actinide oxide specified by the pre-surveillance data. The radiochemical results are generally in good agreement with the pre-surveillance data for mixtures containing 'weapons grade' Pu (nominally 94% {sup 239}Pu and 6% {sup 240}Pu); however, the ICP-MS results from the present investigation generally produce lower concentrations of Pu than the pre-surveillance analyses. For mixtures containing 'fuel grade' Pu (nominally 81-93% {sup 239}Pu and 7-19% {sup 240}Pu), the ICP-MS results from the present investigation appear to be in better agreement with the pre-surveillance data than the radiochemistry results.

  4. A feasibility study for transportable 241Am-in-lung and 241Am-in-nose-blow monitoring systems for use following a weapons accident.

    PubMed

    Youngman, M J; Etherington, G; Smith, J R H

    2003-01-01

    In a nuclear weapon accident involving fire or conventional explosion, most of the radiation dose received by people in the immediate vicinity would result from inhalation of 239Pu. This is accompanied by the nuclide 241Am, which is much easier to determine by external counting because of the 60 keV gamma ray emission. In the event of an accident, a priority would be to identify any people who have had intakes of 239Pu which were so large that decorporation therapy should be considered. Direct measurement of lung content provides the most rapid and convenient method for assessing intakes by inhalation. A transportable system has been considered as this could be deployed close to the site of the accident and would allow rapid measurements to be made. The feasibility of a transportable 241Am-in-nose-blow and nasal swab measurement system has also been considered. This would be used to help select people for 241Am-in-lung measurements. PMID:14527011

  5. Absolute measurement of the 242Pu neutron-capture cross section

    DOE PAGESBeta

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; et al

    2016-04-21

    Here, the absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n,γ) cross section was made over the incident neutron energy range from thermal to ≈ 6 keV, and the absolute scale of the (n,γ) cross section was set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the crossmore » section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈ 40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n,γ) cross section at the En,R = 2.68 eV resonance is within 2.4% of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30% lower than the evaluated data at En ≈ 1 keV and are approximately 2σ away from the previous measurement at En ≈ 20 keV.« less

  6. Plutonium Isotopes in the Terrestrial Environment at the Savannah River Site, USA. A Long-Term Study

    DOE PAGESBeta

    Armstrong, Christopher R.; Nuessle, Patterson R.; Brant, Heather A.; Hall, Gregory; Halverson, Justin E.; Cadieux, James R.

    2015-01-16

    This work presents the findings of a long term plutonium study at Savannah River Site (SRS) conducted between 2003 and 2013. Terrestrial environmental samples were obtained at Savannah River National Laboratory (SRNL) in A-area. Plutonium content and isotopic abundances were measured over this time period by alpha spectrometry and three stage thermal ionization mass spectrometry (3STIMS). Here we detail the complete sample collection, radiochemical separation, and measurement procedure specifically targeted to trace plutonium in bulk environmental samples. Total plutonium activities were determined to be not significantly above atmospheric global fallout. However, the 238Pu/239+240Pu activity ratios attributed to SRS are abovemore » atmospheric global fallout ranges. The 240Pu/239Pu atom ratios are reasonably consistent from year to year and are lower than fallout, while the 242Pu/239Pu atom ratios are higher than fallout values. Overall, the plutonium signatures obtained in this study reflect a mixture of weapons-grade, higher burn-up, and fallout material. This study provides a blue print for long term low level monitoring of plutonium in the environment.« less

  7. Minimum Critical Values Study

    SciTech Connect

    Fox, P.B.

    2005-07-11

    This report provides minimum critical values for various 30-cm water-reflected uranium and plutonium oxide and nitrate aqueous mixtures as calculated by the SCALE CSAS1X sequence using the 238-group ENDF/B-V neutron cross-section library. The minimum values were determined through parametric searches in one-dimensional geometry. The calculations have been performed to obtain the minimum values: critical volume and mass for spheres, critical radius for cylinders, critical thickness for slabs, and minimum critical concentration (infinite geometry) for the following homogeneous mixtures: (1) UO{sub 2}-H{sub 2}O for 3, 4, 5, 20, and 100 wt % {sup 235}U; (2) UNH for 3, 4, 5, 20, and 100 wt % {sup 235}U; (3) PuO{sub 2}-H{sub 2}O for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu); and (4) PuNH for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu). All bounding surfaces were fully reflected by 30 cm of H{sub 2}O.

  8. Propagation of Nuclear Data Uncertainties for ELECTRA Burn-up Calculations

    NASA Astrophysics Data System (ADS)

    Sjöstrand, H.; Alhassan, E.; Duan, J.; Gustavsson, C.; Koning, A. J.; Pomp, S.; Rochman, D.; Österlund, M.

    2014-04-01

    The European Lead-Cooled Training Reactor (ELECTRA) has been proposed as a training reactor for fast systems within the Swedish nuclear program. It is a low-power fast reactor cooled by pure liquid lead. In this work, we propagate the uncertainties in 239Pu transport data to uncertainties in the fuel inventory of ELECTRA during the reactor lifetime using the Total Monte Carlo approach (TMC). Within the TENDL project, nuclear models input parameters were randomized within their uncertainties and 740 239Pu nuclear data libraries were generated. These libraries are used as inputs to reactor codes, in our case SERPENT, to perform uncertainty analysis of nuclear reactor inventory during burn-up. The uncertainty in the inventory determines uncertainties in: the long-term radio-toxicity, the decay heat, the evolution of reactivity parameters, gas pressure and volatile fission product content. In this work, a methodology called fast TMC is utilized, which reduces the overall calculation time. The uncertainty of some minor actinides were observed to be rather large and therefore their impact on multiple recycling should be investigated further. It was also found that, criticality benchmarks can be used to reduce inventory uncertainties due to nuclear data. Further studies are needed to include fission yield uncertainties, more isotopes, and a larger set of benchmarks.

  9. Measurements of fission yields in the heavy region at the recoil ass spectrometer lohengrin

    NASA Astrophysics Data System (ADS)

    Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Köster, U.; Faust, H.; Letourneau, A.; Panebianco, S.; Dupont, E.; Michel-Sendis, F.

    2009-10-01

    In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupled to a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields in the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. It has been extended in this work to the heavy mass region for the reactions 235U(nth,f), 239Pu(nth,f), and 241Pu(nth,f). For these higher masses an isotopic separation is no longer possible. So, a new method was undertaken with the reaction 239Pu(nth,f) to determine the isotopic yields by γ spectrometry. The results are presented in this paper.

  10. Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys

    SciTech Connect

    Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

    2006-02-07

    We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

  11. Neutron scattering studies in the actinide region. Progress report, August 1, 1992--July 31, 1993

    SciTech Connect

    Kegel, G.H.R.; Egan, J.J.

    1993-09-01

    This report discusses the following topics: Prompt fission neutron energy spectra for {sup 235}U and {sup 239}Pu; Two-parameter measurement of nuclear lifetimes; ``Black`` neutron detector; Data reduction techniques for neutron scattering experiments; Inelastic neutron scattering studies in {sup 197}Au; Elastic and inelastic scattering studies in {sup 239}Pu; and neutron induced defects in silicon dioxide MOS structures.

  12. Climate determinism or Geomagnetic determinism?

    NASA Astrophysics Data System (ADS)

    Gallet, Y.; Genevey, A.; Le Goff, M.; Fluteau, F.; Courtillot, V.

    2006-12-01

    A number of episodes of sharp geomagnetic field variations (in both intensity and direction), lasting on the order of a century, have been identified in archeomagnetic records from Western Eurasia and have been called "archeomagnetic jerks". These seem to correlate well with multi-decadal cooling episodes detected in the North Atlantic Ocean and Western Europe, suggesting a causal link between both phenomena. A possible mechanism could be a geomagnetic modulation of the cosmic ray flux that would control the nucleation rate of clouds. We wish to underline the remarkable coincidence between archeomagnetic jerks, cooling events in Western Europe and drought periods in tropical and sub-tropical regions of the northern hemisphere. The latter two can be interpreted in terms of global teleconnections among regional climates. It has been suggested that these climatic variations had caused major changes in the history of ancient civilizations, such as in Mesopotamia, which were critically dependent on water supply and particularly vulnerable to lower rainfall amounts. This is one of the foundations of "climate determinism". Our studies, which suggest a geomagnetic origin for at least some of the inferred climatic events, lead us to propose the idea of a "geomagnetic determinism" in the history of humanity.

  13. Criticality Evaluation of Plutonium-239 Moderated by High-Density Polyethylene in Stainless Steel and Aluminum Containers Suitable for Non-Exclusive Use Transport

    SciTech Connect

    Watson, T T

    2007-08-10

    Research is conducted at the Joint Actinide Shock Physics Experimental Facility (JASPER) on the effects of high pressure and temperature environments on plutonium-239, in support of the stockpile stewardship program. Once an experiment has been completed, it is necessary to transport the end products for interim storage or final disposition. Federal shipping regulations for nonexclusive use transportation require that no more than 180 grams of fissile material are present in at least 360 kilograms of contiguous non-fissile material. To evaluate the conservatism of these regulatory requirements, a worst-case scenario of 180g {sup 239}Pu and a more realistic scenario of 100g {sup 239}Pu were modeled using one of Lawrence Livermore National Laboratory's Monte Carlo transport codes known as COG 10. The geometry consisted of {sup 239}Pu spheres homogeneously mixed with high-density polyethylene surrounded by a cube of either stainless steel 304 or aluminum. An optimized geometry for both cube materials and hydrogen-to-fissile isotope (H/X) ratio were determined for a single unit. Infinite and finite 3D arrays of these optimized units were then simulated to determine if the systems would exceed criticality. Completion of these simulations showed that the optimal H/X ratio for the most reactive units ranged from 800 to 1600. A single unit of either cube type for either scenario would not reach criticality. An infinite array was determined to reach criticality only for the 180g case. The offsetting of spheres in their respective cubes was also considered and showed a considerable decrease in the number of close-packed units needed to reach criticality. These results call into question the current regulations for fissile material transport, which under certain circumstances may not be sufficient in preventing the development of a critical system. However, a conservative, theoretical approach was taken in all assumptions and such idealized configurations may not be likely to

  14. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    SciTech Connect

    G. Youinou; M. Salvatores; M. Paul; R. Pardo; G. Palmiotti; F. Kondev; G. Imel

    2010-04-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  15. Precision spectroscopy with reactor antineutrinos

    NASA Astrophysics Data System (ADS)

    Huber, Patrick; Schwetz, Thomas

    2004-09-01

    In this work we present an accurate parameterization of the antineutrino flux produced by the isotopes 235U, 239Pu, and 241Pu in nuclear reactors. We determine the coefficients of this parameterization, as well as their covariance matrix, by performing a fit to spectra inferred from experimentally measured beta spectra. Subsequently we show that flux shape uncertainties play only a minor role in the KamLAND experiment, however, we find that future reactor-neutrino experiments to measure the mixing angle θ13 are sensitive to the fine details of the reactor-neutrino spectra. Finally, we investigate the possibility to determine the isotopic composition in nuclear reactors through an antineutrino measurement. We find that with a three month exposure of a 1ton detector the isotope fractions and the thermal reactor power can be determined at a few percent accuracy, which may open the possibility of an application for safeguard or nonproliferation objectives.

  16. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    SciTech Connect

    G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

    2011-08-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  17. Nuclear and dosimetric features of an isotopic neutron source

    NASA Astrophysics Data System (ADS)

    Vega-Carrillo, H. R.; Hernández-Dávila, V. M.; Rivera, T.; Sánchez, A.

    2014-02-01

    A multisphere neutron spectrometer was used to determine the features of a 239PuBe neutron source that is used to operate the ESFM-IPN Subcritical Reactor. To determine the source main features it was located a 100 cm from the spectrometer which was a 6LiI(Eu) scintillator and 2, 3, 5, 8, 10 and 12 in.-diameter polyethylene spheres. Count rates obtained with the spectrometer were unfolded using the NSDUAZ code and neutron spectrum, total fluence, and ambient dose equivalent were determined. A Monte Carlo calculation was carried out to estimate the spectrum and integral features being less than values obtained experimentally due to the presence of 241Pu in the Pu used to fabricate the source. Actual neutron yield and the mass fraction of 241Pu was estimated.

  18. Test of pre-ENDF/B-VI decay data and fission yields

    SciTech Connect

    Rudstam, G.; England, T.R.

    1990-10-01

    Pre-ENDF/B-VI nuclear decay data and fission yields have been supplemented by average beta and gamma energies and Pn-values from recent experiments at Studsvik. This data base has been used for a series of summation calculations, and the results have been compared with experimental determinations of decay heat and of delayed-neutron effects. The comparisons are limited to thermal fission of {sup 235}U and {sup 239}Pu and to fast fission of {sup 238}U. The general impression of the comparisons is that the data base does reproduce experimental results satisfactorily (with a few exceptions) within the combined limits of error of the experimental determinations and the calculation. 21 refs., 15 figs.

  19. SUBSURFACE MOBILE PLUTONIUM SPECIATION: SAMPLING ARTIFACTS FOR GROUNDWATER COLLOIDS

    SciTech Connect

    Kaplan, D.; Buesseler, K.

    2010-06-29

    A recent review found several conflicting conclusions regarding colloid-facilitated transport of radionuclides in groundwater and noted that colloids can both facilitate and retard transport. Given these contrasting conclusions and the profound implications even trace concentrations of plutonium (Pu) have on the calculated risk posed to human health, it is important that the methodology used to sample groundwater colloids be free of artifacts. The objective of this study was: (1) to conduct a field study and measure Pu speciation, ({sup 239}Pu and {sup 240}Pu for reduced-Pu{sub aq}, oxidized-Pu{sub aq}, reduced-Pu{sub colloid}, and oxidized-Pu{sub colloid}), in a Savannah River Site (SRS) aquifer along a pH gradient in F-Area, (2) to determine the impact of pumping rate on Pu concentration, Pu speciation, and Pu isotopic ratios, (3) determine the impact of delayed sample processing (as opposed to processing directly from the well).

  20. Uranium from German Nuclear Power Projects of the 1940s--A Nuclear Forensic Investigation.

    PubMed

    Mayer, Klaus; Wallenius, Maria; Lützenkirchen, Klaus; Horta, Joan; Nicholl, Adrian; Rasmussen, Gert; van Belle, Pieter; Varga, Zsolt; Buda, Razvan; Erdmann, Nicole; Kratz, Jens-Volker; Trautmann, Norbert; Fifield, L Keith; Tims, Stephen G; Fröhlich, Michaela B; Steier, Peter

    2015-11-01

    Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel. Through measurement of the (230)Th/(234)U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare-earth-element content and the (87)Sr/(86)Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of (236)U and (239)Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence. PMID:26501922

  1. Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation

    PubMed Central

    Mayer, Klaus; Wallenius, Maria; Lützenkirchen, Klaus; Horta, Joan; Nicholl, Adrian; Rasmussen, Gert; van Belle, Pieter; Varga, Zsolt; Buda, Razvan; Erdmann, Nicole; Kratz, Jens-Volker; Trautmann, Norbert; Fifield, L Keith; Tims, Stephen G; Fröhlich, Michaela B; Steier, Peter

    2015-01-01

    Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel.3b,d, 4 Through measurement of the 230Th/234U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare-earth-element content and the 87Sr/86Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of 236U and 239Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence. PMID:26501922

  2. Measurements of alpha particle energy using nuclear tracks in solids methodology.

    PubMed

    Espinosa, G; Amero, C; Gammage, R B

    2002-01-01

    In this paper we present a method for the measurement of alpha particle energy using polycarbonate materials as nuclear track detectors (NTDs). This method is based on the interaction of the radiation with the solid-state materials, using the relationship between the energy deposited in the material by the ionising particle and the track developed after an established chemical process. The determination of the geometrical parameters of the formed track, such as major axis, minor axis and overall track length, permit determination of the energy of the alpha particle. The track analysis is performed automatically using a digital image system, and the data are processed in a PC with commercial software. In this experiment 148Gd, 238U, 230Th, 239Pu and 244Cm alpha particle emitters were used. The values for alpha particle energy resolution, the linear response to energy, the confidence in the results and the automatisation of the procedure make this method a promising analysis system. PMID:12382812

  3. Rotational constants and structure of para-difluorobenzene determined by femtosecond Raman coherence spectroscopy: A new transient type

    NASA Astrophysics Data System (ADS)

    Den, Takuya; Frey, Hans-Martin; Felker, Peter M.; Leutwyler, Samuel

    2015-10-01

    Femtosecond Raman rotational coherence spectroscopy (RCS) detected by degenerate four-wave mixing is a background-free method that allows to determine accurate gas-phase rotational constants of non-polar molecules. Raman RCS has so far mostly been applied to the regular coherence patterns of symmetric-top molecules, while its application to nonpolar asymmetric tops has been hampered by the large number of RCS transient types, the resulting variability of the RCS patterns, and the 103-104 times larger computational effort to simulate and fit rotational Raman RCS transients. We present the rotational Raman RCS spectra of the nonpolar asymmetric top 1,4-difluorobenzene (para-difluorobenzene, p-DFB) measured in a pulsed Ar supersonic jet and in a gas cell over delay times up to ˜2.5 ns. p-DFB exhibits rotational Raman transitions with ΔJ = 0, 1, 2 and ΔK = 0, 2, leading to the observation of J -, K -, A -, and C-type transients, as well as a novel transient (S-type) that has not been characterized so far. The jet and gas cell RCS measurements were fully analyzed and yield the ground-state (v = 0) rotational constants A0 = 5637.68(20) MHz, B0 = 1428.23(37) MHz, and C0 = 1138.90(48) MHz (1σ uncertainties). Combining the A0, B0, and C0 constants with coupled-cluster with single-, double- and perturbatively corrected triple-excitation calculations using large basis sets allows to determine the semi-experimental equilibrium bond lengths re(C1-C2) = 1.3849(4) Å, re(C2-C3) = 1.3917(4) Å, re(C-F) = 1.3422(3) Å, and re(C2-H2) = 1.0791(5) Å.

  4. Empirical Confirmation of the Critical Level for Zero and Near Zero Background Measurements

    SciTech Connect

    Hickman, D P; Simpson, T

    2001-06-01

    The alpha spectroscopy system of the Lawrence Livermore National Laboratory, Hazards Control Department evaluates electroplated samples, typically urine and feces, for alpha emitting radionuclides. Most of the samples processed by the alpha spectroscopy system are evaluated for Plutonium-239 (Pu-239), an important radionuclide used in research. This paper evaluates the Pu-239 background response of the Lawrence Livermore National Laboratory Hazards Control Department's alpha spectroscopy system. Background measurements of the alpha spectroscopy system have been studied to determine an appropriate method for establishing the a postori critical level for detection of plutonium alpha activity. Several methods of establishing the 95% confidence interval for over 4,900 background measurements were evaluated. Two methods appear to provide reasonable results so as to assure an appropriate 95% confidence interval. This report provides the results of this evaluation and the comparison of the various methods tested to establish an empirical evaluation of the critical level using a commercially available analysis program.

  5. Plutonium-239, /sup 240/Pu and /sup 210/Po contents of tobacco and cigarette smoke

    SciTech Connect

    Mussalo-Rauhamaa, H.; Jaakkola, T.

    1985-08-01

    The /sup 239/Pu and /sup 240/Pu found in the environment has mainly been produced by atmospheric nuclear tests. The accumulation of fallout Pu in man from inhalation and ingestion and its distribution in the body has previously been studied. Information about the accumulation is needed because of the expanding production of this highly radiotoxic substance. In the present work the Pu content of tobacco and cigarette smoke was determined to evaluate the contribution of smoking to total Pu intake by man. For comparison the /sup 210/Po content of tobacco and smoke were analyzed. The release of /sup 210/Po in tobacco smoke and the radiation dose for man have been widely studied because of the high incidence of lung cancer among smokers.

  6. Baseline concentrations of radionuclides and heavy metals in soils and vegetation around the DARHT facility: Construction phase (1996)

    SciTech Connect

    Fresquez, P.R.; Haagenstad, H.T.; Naranjo, L. Jr.

    1997-04-01

    As part of the Department of Energy`s Mitigation Action Plan for the Dual Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory (LANL), baseline concentrations of radionuclides ({sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu, {sup 241}Am, total U), and heavy metals (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se and Tl) in soil, sediment, and vegetation (overstory and understory) around the DARHT facility during the construction phase in 1996 were determined. Also, U and Be concentrations in soil samples collected in 1993 from within the proposed DARHT facility area are reported. Most radionuclides in soils, sediments, and vegetation were within current background and/or long-term regional statistical reference levels.

  7. Advanced alpha spectrum analysis based on the fitting and covariance analysis of dependent variables

    NASA Astrophysics Data System (ADS)

    Ihantola, S.; Pelikan, A.; Pöllänen, R.; Toivonen, H.

    2011-11-01

    The correct handling of statistical uncertainties is crucial especially when unfolding alpha spectra that contain a low number of counts or overlapping peaks from different nuclides. For this purpose, we have developed a new spectrum analysis software package called ADAM, which performs a full covariance calculus for alpha-particle emitting radionuclides. By analyzing a large number of simulated and measured spectra, the program was proved to give unbiased peak areas and statistically correct uncertainty limits. This applies regardless of the peak areas and the number of unknown parameters during the fitting. In addition, ADAM performs reliable deconvolution for multiplets, which opens the way for the determination of isotope ratios, such as 239Pu/240Pu.

  8. Surrogate measurement of the {sup 238}Pu(n,f) cross section

    SciTech Connect

    Ressler, J. J.; Burke, J. T.; Escher, J. E.; Bernstein, L. A.; Bleuel, D. L.; Casperson, R. J.; Gostic, J.; Henderson, R.; Scielzo, N. D.; Thompson, I. J.; Wiedeking, M.; Angell, C. T.; Goldblum, B. L.; Munson, J.; Basunia, M. S.; Phair, L. W.; Beausang, C. W.; Hughes, R. O.; Hatarik, R.; Ross, T. J.

    2011-05-15

    The neutron-induced fission cross section of {sup 238}Pu was determined using the surrogate ratio method. The (n,f) cross section over an equivalent neutron energy range 5-20 MeV was deduced from inelastic {alpha}-induced fission reactions on {sup 239}Pu, with {sup 235}U({alpha},{alpha}{sup '}f) and {sup 236}U({alpha},{alpha}{sup '}f) used as references. These reference reactions reflect {sup 234}U(n,f) and {sup 235}U(n,f) yields, respectively. The deduced {sup 238}Pu(n,f) cross section agrees well with standard data libraries up to {approx}10 MeV, although larger values are seen at higher energies. The difference at higher energies is less than 20%.

  9. Nuclear Fission Research at IRMM

    SciTech Connect

    Hambsch, Franz-Josef

    2005-05-24

    The Institute for Reference Materials and Measurements (IRMM) will celebrate its 45th anniversary in 2005. With its 150-MeV Geel Electron Linear Accelerator (GELINA) and 7-MV Van de Graaff accelerator as multi-purpose neutron sources, it served the nuclear physics community for this period.The research in the field of nuclear fission was focused in recent years on both the measurement and calculation of fission cross sections, and the measurement of fission fragment properties.Fission cross sections were determined for 233Pa and 234U; the fission process was studied in the resolved resonance region of 239Pu(n,f) and for 251Cf(nth,f). These measurements derive their interest from accelerator driven systems, the thorium fuel cycle, high temperature reactors, safety issues of current reactors, and basic physics. The measurements are supported by several modeling efforts that aim at improving model codes and nuclear data evaluation.

  10. Radiological dose assessments in the northern Marshall Islands (1989--1991)

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1992-01-01

    The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides, such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods.

  11. Ultra-high-resolution alpha spectrometry for nuclear forensics and safeguards applications

    SciTech Connect

    Bacrania, Minesh K; Croce, Mark; Bond, Evelyn; Dry, Donald; Moody, W. Allen; Lamont, Stephen; Rabin, Michael; Rim, Jung; Smith, Audrey; Beall, James; Bennett, Douglas; Kotsubo, Vincent; Horansky, Robert; Hilton, Gene; Schmidt, Daniel; Ullom, Joel; Cantor, Robin

    2010-01-01

    We will present our work on the development of ultra-high-resolution detectors for alpha particle spectrometry. These detectors, based on superconducting transition-edge sensors, offer energy resolution that is five to ten times better than conventional silicon detectors. Using these microcalorimeter detectors, the isotopic composition of mixed-actinide samples can be determined rapidly without the need for actinide separation chemistry to isolate each element, or mass spectrometry to separate isotopic signatures that can not be resolved using traditional alpha spectrometry (e.g. Pu-239/Pu-240, or Pu-238/Am-241). This paper will cover the detector and measurement system, actinide source preparation, and the quantitative isotopic analysis of a number of forensics- and safeguards-relevant radioactive sources.

  12. Direct isotope ratio analysis of individual uranium-plutonium mixed particles with various U/Pu ratios by thermal ionization mass spectrometry.

    PubMed

    Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki

    2015-02-01

    Uranium and plutonium isotope ratios in individual uranium-plutonium (U-Pu) mixed particles with various U/Pu atomic ratios were analyzed without prior chemical separation by thermal ionization mass spectrometry (TIMS). Prior to measurement, micron-sized particles with U/Pu ratios of 1, 5, 10, 18, and 70 were produced from uranium and plutonium certified reference materials. In the TIMS analysis, the peaks of americium, plutonium, and uranium ion signals were successfully separated by continuously increasing the evaporation filament current. Consequently, the uranium and plutonium isotope ratios, except the (238)Pu/(239)Pu ratio, were successfully determined for the particles at all U/Pu ratios. This indicates that TIMS direct analysis allows for the measurement of individual U-Pu mixed particles without prior chemical separation. PMID:25479434

  13. Minior Actinide Doppler Coefficient Measurement Assessment

    SciTech Connect

    Nolan E. Hertel; Dwayne Blaylock

    2008-04-10

    The "Minor Actinide Doppler Coefficient Measurement Assessment" was a Department of Energy (DOE) U-NERI funded project intended to assess the viability of using either the FLATTOP or the COMET critical assembly to measure high temperature Doppler coefficients. The goal of the project was to calculate using the MCNP5 code the gram amounts of Np-237, Pu-238, Pu-239, Pu-241, AM-241, AM-242m, Am-243, and CM-244 needed to produce a 1E-5 in reactivity for a change in operating temperature 800C to 1000C. After determining the viability of using the assemblies and calculating the amounts of each actinide an experiment will be designed to verify the calculated results. The calculations and any doncuted experiments are designed to support the Advanced Fuel Cycle Initiative in conducting safety analysis of advanced fast reactor or acceoerator-driven transmutation systems with fuel containing high minor actinide content.

  14. Analysis of spent fuel assay with a lead slowing down spectrometer

    SciTech Connect

    Gavron, Victor I; Smith, L Eric; Ressler, Jennifer J

    2008-01-01

    Assay of fissile materials in spent fuel that are produced or depleted during the operation of a reactor, is of paramount importance to nuclear materials accounting, verification of the reactor operation history, as well as for criticality considerations for storage. In order to prevent future proliferation following the spread of nuclear energy, we must develop accurate methods to assay large quantities of nuclear fuels. We analyze the potential of using a Lead Slowing Down Spectrometer for assaying spent fuel. We conclude that it is possible to design a system that will provide around 1% statistical precision in the determination of the {sup 239}Pu, {sup 241}Pu and {sup 235}U concentrations in a PWR spent-fuel assembly, for intermediate-to-high burnup levels, using commercial neutron sources, and a system of {sup 238}U threshold fission detectors. Pending further analysis of systematic errors, it is possible that missing pins can be detected, as can asymmetry in the fuel bundle.

  15. Analysis of spent fuel assay with a lead slowing down spectrometer

    SciTech Connect

    Gavron, Victor I; Smith, L. Eric; Ressler, Jennifer J

    2010-10-29

    Assay of fissile materials in spent fuel that are produced or depleted during the operation of a reactor, is of paramount importance to nuclear materials accounting, verification of the reactor operation history, as well as for criticality considerations for storage. In order to prevent future proliferation following the spread of nuclear energy, we must develop accurate methods to assay large quantities of nuclear fuels. We analyze the potential of using a Lead Slowing Down Spectrometer for assaying spent fuel. We conclude that it is possible to design a system that will provide around 1% statistical precision in the determination of the {sup 239}Pu, {sup 241}Pu and {sup 235}U concentrations in a PWR spent-fuel assembly, for intermediate-to-high burnup levels, using commercial neutron sources, and a system of {sup 238}U threshold fission detectors. Pending further analysis of systematic errors, it is possible that missing pins can be detected, as can asymmetry in the fuel bundle.

  16. Artificial neural networks technology for neutron spectrometry and dosimetry.

    PubMed

    Vega-Carrillo, H R; Hernández-Dávila, V M; Manzanares-Acuña, E; Gallego, E; Lorente, A; Iñiguez, M P

    2007-01-01

    Artificial Neural Network Technology has been applied to unfold neutron spectra and to calculate 13 dosimetric quantities using seven count rates from a Bonner Sphere Spectrometer with a (6)LiI(Eu). Two different networks, one for spectrometry and another for dosimetry, were designed. To train and test both networks, 177 neutron spectra from the IAEA compilation were utilised. Spectra were re-binned into 31 energy groups, and the dosimetric quantities were calculated using the MCNP code and the fluence-to-dose conversion coefficients from ICRP 74. Neutron spectra and UTA4 response matrix were used to calculate the expected count rates in the Bonner spectrometer. Spectra and H(10) of (239)PuBe and (241)AmBe were experimentally obtained and compared with those determined with the artificial neural networks. PMID:17522034

  17. Plutonium gamma-ray measurements for mutual reciprocal inspections of dismantled nuclear weapons

    SciTech Connect

    Koenig, Z.M.; Carlson, J.B.; Clark, D.; Gosnell, T.B.

    1995-07-01

    The O`Leary-Mikhailov agreement of March 1994 stated that the U.S. and the Russian Federation would engage in mutual reciprocal inspections (MRI) of fissile materials removed from dismantled nuclear weapons. It was decided to begin with the plutonium (Pu) removed from dismantled weapons and held in storage containers. Later discussions between U.S. and Russian technical experts led to the conclusion that, to achieve the O`Leary-Mikhailov objectives, Pu MRI would need to determine that the material in the containers has properties consistent with a nuclear-weapon component. Such a property is a {sup 240}Pu/{sup 239}Pu ratio consistent with weapons-grade material. One of the candidate inspection techniques under consideration for Pu MRI is to use a narrow region (630-670 keV) of the plutonium gamma-ray spectrum, taken with a high-purity germanium detector, to determine that it is weapons-grade plutonium as well as to estimate the minimum mass necessary to produce the observed gamma-ray intensity. We developed software (the Pu600 code) for instrument control and analysis especially for this purpose. In November 1994, U.S. and Russian scientists met at the Lawrence Livermore National Laboratory for joint experiments to evaluate candidate Pu MRI inspection techniques. In one of these experiments, gamma-ray intensities were measured from three unclassified weapons-grade plutonium source standards and one reactor-grade standard (21% {sup 240}pu). Using our software, we determined the {sup 240}Pu/{sup 239}Pu ratio of these standards to accuracies within {+-}10%, which is adequate for Pu MRI. The minimum mass estimates varied, as expected, directly with the exposed surface area of the standards.

  18. TRU Waste Assay Methodology with the Combined Thermal Epithermal Neutron (CTEN) System

    SciTech Connect

    Veilleux, J. M.; Enter, J. A.

    2003-02-27

    The CTEN assay system is designed to measure plutonium bearing 208-L waste drums and make the transuranic versus low-level waste determination. The system was certified for Waste Isolation Pilot Plant operations and the Environmental Protection Agency approved the CTEN in 2002. It is the only system capable of making the transuranic/low-level waste (TRU/LLW) determination since it can routinely assay below 100 nCi/g. The system conducts a measurement by using either (or both) an active 14 MeV neutron pulse to induce fission in 239Pu and 241Pu or measures the spontaneous fission properties of 238Pu, 240Pu and 242Pu. When the coincidence neutron signal is combined with mass fraction data from a gamma system, the result is the total plutonium mass. The system's lower limit of detection is as low as 2 mg of weapons grade plutonium, making it an ideal platform to make the TRU/LLW determination. Analysis of an assay is made with visual basic application driven subroutines and Micros oft Excel spreadsheets. Input values and calculations include: the raw neutron scaler and coincidence counts; mass fraction information; plutonium mass; alpha, total and TRU activity; thermal power, 239Pu Equivalent Curies; fissile gram equivalent mass; decay heat; and uncertainties associated with each parameter. A general diagnostic analysis is performed for each assay to facilitate a technical review of the results. The results of analysis from 372 waste drums are summarized. The results indicate that modifying current operating procedures involving the use of acceptable knowledge isotope data and use of the lower detection limit could increase the number of certifiable assays from 38% to 66%.

  19. Plutonium in human urine: Normal levels in the US public. 1991 Annual report, Volume 2

    SciTech Connect

    Wrenn, M.E.; Singh, N.P.; Xue, Ying-Hua

    1997-03-01

    A neutron induced fission track method was successfully developed for assaying {sup 239}Pu in human urine with a detection limit below 20 aCi/sample. The technique involves the co-precipitation of {sup 239}Pu with rhodizonic acid, separation of {sup 239}Pu from potentially interfering natural uranium and other inorganic materials by ion-exchange techniques, collection of the sample onto lexan detectors, irradiation of sample in MIT reactor at a fluence of 1.1 x 10{sup 17} n/cm{sup 2}, etching of the lexan slide and counting the track either manually or by some automated counting system.

  20. Isotopic fingerprinting of the world's first nuclear device using post-detonation materials.

    PubMed

    Bellucci, Jeremy J; Simonetti, Antonio; Wallace, Christine; Koeman, Elizabeth C; Burns, Peter C

    2013-04-16

    In the event of a rogue nuclear attack or interception of illicit nuclear materials, timely forensic investigations are critical for accurate source attribution. Uranium (U) and plutonium (Pu) isotopic ratios of intercepted materials or postdetonation samples are, perhaps, the most valuable evidence in modern nuclear forensics. These ratios simultaneously provide information regarding the material's ''age'' (i.e., time elapsed since last purification), actinide concentrations, and relevant isotopic ratios/enrichment values. Consequently, these isotope signatures are invaluable in determining the origin, processing history, and intended purpose of any nuclear material. Here we show, for the first time, that it is feasible to determine the U and Pu isotopic compositions of historic nuclear devices from their postdetonation materials utilizing in situ U isotopic measurements. The U isotopic compositions of trinitite glass, produced subsequent to the world's first atomic explosion, indicate two sources: the device's tamper, composed of natural U that underwent fission during detonation, and natural U from the geological background. Enrichments in (234,235,236)U reflect the in situ decay of (238,239,240)Pu, the fuel used in the device. Time-integrated U isotopic modeling yields "supergrade" compositions, where (240)Pu/(239)Pu ≈ 0.01-0.03 and (238)Pu/(239)Pu ≈ 0.00011-0.00017, which are consistent with the Pu originating from the Hanford reactor. Spatially resolved U isotopic data of postdetonation debris reveal important details of the device in a relatively short time frame (hours). This capacity serves as an important deterrent to future nuclear threats and/or terrorist activities and is critical for source attribution and international security. PMID:23517046

  1. Assessment of Nuclear Resonance Fluorescence for Spent Nuclear Fuel Assay

    SciTech Connect

    Quiter, Brian; Ludewigt, Bernhard; Ambers, Scott

    2011-06-30

    In nuclear resonance fluorescence (NRF) measurements, resonances are excited by an external photon beam leading to the emission of gamma rays with specific energies that are characteristic of the emitting isotope. NRF promises the unique capability of directly quantifying a specific isotope without the need for unfolding the combined responses of several fissile isotopes as is required in other measurement techniques. We have analyzed the potential of NRF as a non-destructive analysis technique for quantitative measurements of Pu isotopes in spent nuclear fuel (SNF). Given the low concentrations of 239Pu in SNF and its small integrated NRF cross sections, the main challenge in achieving precise and accurate measurements lies in accruing sufficient counting statistics in a reasonable measurement time. Using analytical modeling, and simulations with the radiation transport code MCNPX that has been experimentally tested recently, the backscatter and transmission methods were quantitatively studied for differing photon sources and radiation detector types. Resonant photon count rates and measurement times were estimated for a range of photon source and detection parameters, which were used to determine photon source and gamma-ray detector requirements. The results indicate that systems based on a bremsstrahlung source and present detector technology are not practical for high-precision measurements of 239Pu in SNF. Measurements that achieve the desired uncertainties within hour-long measurements will either require stronger resonances, which may be expressed by other Pu isotopes, or require quasi-monoenergetic photon sources with intensities that are approximately two orders of magnitude higher than those currently being designed or proposed.This work is part of a larger effort sponsored by the Next Generation Safeguards Initiative to develop an integrated instrument, comprised of individual NDA techniques with complementary features, that is fully capable of

  2. The In-Vitro Transport of (238)PLUTONIUM Oxide and (239)PLUTONIUM Oxide Through a Membrane Filter and its Importance for Internal Radiation Dosimetry.

    NASA Astrophysics Data System (ADS)

    Ryan, Michael Terrance

    These experiments were designed to determine if ('238)PuO(,2), due to its higher specific activity and attendant aggregate recoil, undergoes higher transfer through a membrane filter into an interstitial human alveolar lung fluid simulant than ('239)PuO(,2). The rate at which such transfer occurs was determined in an in-vitro chamber designed to simulate residence characteristics of particles of insoluble plutonium oxides in human alveolar interstitium. The ratio of the rate of ('238)Pu/('239)Pu transfer was 138 (+OR -) 76%. Calculations were performed to assess the importance of this finding in terms of the internal dosimetry of insoluble ('238)Pu using methods and models recommended by the International Commission on Radiological Protection. Three cases were evaluated, namely integral 50-year dose commitment, urinary excretion after single acute intake and urinary excretion rate during chronic constant intake. It was found that integral 50-year dose commitments were not influenced by the rate of plutonium transfer from the pulmonary compartment to blood. The evaluation of calculated urinary excretion data after a single acute inhalation intake showed that in the early period, up to about 30 days post exposure, urinary excretion of ('238)PuO(,2) may be 2 to 10 times higher than the urinary excretion rate for ('238)PuO(,2) predicted by the ICRP reference model. From about 50 days to approximately 1000 days the calculated urinary excretion rate for ('238)PuO(,2) may be lower than that predicted by the reference model by a factor of 2 to 10. In the case of chronic constant intake the calculated urinary excretion rate for ('238)PuO(,2) may be up to a factor of 2 higher than that predicted by the reference ICRP Model.

  3. Real time studies of Elastic Moduli Pu Aging using Resonant Ultrasound Spectroscopy

    NASA Astrophysics Data System (ADS)

    Maiorov, Boris

    Elastic moduli are fundamental thermodynamic susceptibilities that connect directly to thermodynamics, electronic structure and give important information about mechanical properties. To determine the time evolution of the elastic properties in 239Pu and it Ga alloys, is imperative to study its phase stability and self-irradiation damage process. The most-likely sources of these changes include a) ingrowth of radioactive decay products like He and U, b) the introduction of radiation damage, c) δ-phase instabilities towards α-Pu or to Pu3Ga. The measurement of mechanical resonance frequencies can be made with extreme precision and used to compute the elastic moduli without corrections giving important insight in this problem. Using Resonant Ultrasound Spectroscopy, we measured the time dependence of the mechanical resonance frequencies of fine-grained polycrystalline δ-phase 239Pu, from 300K up to 480K. At room temperature, the shear modulus shows an increase in time (stiffening), but the bulk modulus decreases (softening). These are the first real-time measurements of room temperature aging of the elastic moduli, and the changes are consistent with elastic moduli measurements performed on 44 year old δ-Pu. As the temperature is increased, the rate of change increases exponentially, with both moduli becoming stiffer with time. For T>420K an abrupt change in the time dependence is observed indicating that the bulk and shear moduli have opposite rates of change. Our measurements provide a basis for ruling out the decomposition of δ-Pu towards α-Pu or Pu3Ga, and indicate a complex defect-related scenario from which we are gathering important clues.

  4. Methodology using a portable X-ray fluorescence device for on-site and rapid evaluation of heavy-atom contamination in wounds: a model study for application to plutonium contamination.

    PubMed

    Yoshii, Hiroshi; Yanagihara, Kouta; Imaseki, Hitoshi; Hamano, Tsuyoshi; Yamanishi, Hirokuni; Inagaki, Masayo; Sakai, Yasuhiro; Sugiura, Nobuyuki; Kurihara, Osamu; Sakai, Kazuo

    2014-01-01

    Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF) device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL) of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol). The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds. PMID:25010749

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

    SciTech Connect

    MacLellan, J.A.

    1988-09-01

    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.

  6. Methodology Using a Portable X-Ray Fluorescence Device for On-Site and Rapid Evaluation of Heavy-Atom Contamination in Wounds: A Model Study for Application to Plutonium Contamination

    PubMed Central

    Yoshii, Hiroshi; Yanagihara, Kouta; Imaseki, Hitoshi; Hamano, Tsuyoshi; Yamanishi, Hirokuni; Inagaki, Masayo; Sakai, Yasuhiro; Sugiura, Nobuyuki; Kurihara, Osamu; Sakai, Kazuo

    2014-01-01

    Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF) device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL) of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol). The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds. PMID:25010749

  7. Lung tumor response to inhaled Pu and its implications for radiation protection

    SciTech Connect

    Sanders, C.L.; McDonald, K.E.; Mahaffey, J.A.

    1988-08-01

    Multistage models of cancer induction have been accepted in chemical and radiation carcinogenesis for many years. Most models assume that both initiating and promoting events are required for greatest expression of tumor incidence. The sequence of events is important in determining the shape of the dose-response curve. A total of 1058 female, SPF, Wistar, sham-exposed rats and 2134 rats given a single inhalation to 169Yb, 239PuO2 are being studied for lung tumor formation in a life-span study. Histopathological analyses have been completed on 1149 rats. Similar dose-response curves are seen for pulmonary fibrosis pulmonary metaplasia and lung tumor formation. Lung tumor incidences were: 0.6% (0 Gy), 0.5% (0.06 Gy), 0% (0.11 Gy), 0% (0.23 Gy), 4.5% (0.46 Gy), 0% (0.84 Gy), 13.8% (1.9 Gy), 18.6% (3.5 Gy), 72.5% (7.4 Gy), and 84.9% (15 Gy). The dose lung-tumor curve was best fit by a quadratic function and was not well fit by a linear function. It is proposed that the low-dose portion of the quadratic curve represents promotion event(s) due to increasing 239PuO2 particle clustering in subpleural regions, leading to a cellular evolution of focally intense inflammation, fibrosis, epithelial metaplasia and carcinoma formation. A defined, practical threshold dose may be useful with respect to setting radiation protection guidelines for lung tumor induction.

  8. Field test of New TASTEX system for plutonium product verification at the Tokai Reprocessing Plant

    SciTech Connect

    Kuno, Y.; Shigeoka, K.; Nishida, K.; Ikeda, H.; Hayashi, N.; Wachi, I.; Hsue, S.T.; Sprinkle, J.K.; Gunnink, R.; Ruhter, W.D.

    1988-01-01

    This report describes the field test results of the New TASTEX system. This system consisting of the high resolution gamma spectrometer and the k-edge densitometer can measure both isotopic abundances and concentration of plutonium simultaneously. Entire system is controlled by the multichannel analyzer and a multi-user computer. The system was designed and built under the Japan Support Program for Agency Safeguards (JASPAS). The software of this system developed at LANL and LLNL has been installed in the system assembled at the Tokai reprocessing plant (TRP) in July 1985. In the course of campaigns from 1985 until 1988, field tests have been carried out on plutonium product solutions of TRP. The results of plutonium concentration and isotopic abundances obtained by the k-edge densitometer and the high resolution gamma spectrometer (HRGS) have been compared with those by controlled potential coulometer and mass spectrometer respectively. Precision of plutonium determination with k-edge densitometer is estimated approximately 0.7% and 1.0% for the freshly processed plutonium and the aged plutonium respectively. The scatters in the relative differences between HRGS and the destructive analysis (DA) detected on the results of freshly processed plutonium sample were 1.6%, 0.4%, 0.5%, 1.1%, 8.0% for Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242 respectively, whereas those on the results of aged sample were 1.4%, 0.5%, 1.1%, 1.1% for Pu-238, Pu-239, Pu-240, and Pu-241 respectively. 9 refs., 15 figs., 7 tabs.

  9. Vegetation uptake from burial ground alpha waste trenches

    SciTech Connect

    Murphy, C.E. Jr.; Tuckfield, R.C.

    1989-01-01

    This study was conducted as part of an evaluation of the potential radiological consequences of reinhabiting the SRS burial ground. The objective was to determine the uptake of buried, low-level, transuranic waste from unlined earthen trenches by forest vegetation. Two tree plots were established in 1979. One plot was put over a trench containing alpha waste and the other in an area without trenches. When the tree seedlings were sampled during 1979 and 1980, and analysized for {sup 239}Pu and {sup 238}Pu, there was only a small difference in radionuclude concentration between trees planted over the trench and those planted on the control plot because of the limited root intrusion into the trench by the seedlings. However, when trees were sample in 1986, 1987, and 1988 and analyzed for {sup 241}Am, {sup 238}Pu, {sup 239}Pu, and {sup 237}Np activity, the average activity of all of these isotopes was significantly higher over the trenches than in the control plot. These measurements indicate that tree roots will extract transuranic isotopes from buried, low-level waste. The amount of radioisotopes moved from the trenches to the surface is small and the level in the trees is low enough that dose from exposure will be small. The long term effects of transport of radioisotopes from the trenches to the surface soil was evaluated by estimating the accumulation in the surface soil. Transuranic activity in selected food crops was calculated using the soil activity and the literature derived concentration factors. In all cases, the activity of the transuranic isotopes in the edible portion of the plants was quite low. The activity in the leaf tissue was much higher than in the seed. However, it should be noted that in only one case was the activity higher than the naturally occurring activity of {sup 40}K in the pine foliage.

  10. Rotational spectra of rare isotopic species of fluoroiodomethane: Determination of the equilibrium structure from rotational spectroscopy and quantum-chemical calculations

    NASA Astrophysics Data System (ADS)

    Puzzarini, Cristina; Cazzoli, Gabriele; López, Juan Carlos; Alonso, José Luis; Baldacci, Agostino; Baldan, Alessandro; Stopkowicz, Stella; Cheng, Lan; Gauss, Jürgen

    2012-07-01

    Supported by accurate quantum-chemical calculations, the rotational spectra of the mono- and bi-deuterated species of fluoroiodomethane, CHDFI and CD2FI, as well as of the 13C-containing species, 13CH2FI, were recorded for the first time. Three different spectrometers were employed, a Fourier-transform microwave spectrometer, a millimeter/submillimter-wave spectrometer, and a THz spectrometer, thus allowing to record a huge portion of the rotational spectrum, from 5 GHz up to 1.05 THz, and to accurately determine the ground-state rotational and centrifugal-distortion constants. Sub-Doppler measurements allowed to resolve the hyperfine structure of the rotational spectrum and to determine the complete iodine quadrupole-coupling tensor as well as the diagonal elements of the iodine spin-rotation tensor. The present investigation of rare isotopic species of CH2FI together with the results previously obtained for the main isotopologue [C. Puzzarini, G. Cazzoli, J. C. López, J. L. Alonso, A. Baldacci, A. Baldan, S. Stopkowicz, L. Cheng, and J. Gauss, J. Chem. Phys. 134, 174312 (2011);, 10.1063/1.3583498 G. Cazzoli, A. Baldacci, A. Baldan, and C. Puzzarini, Mol. Phys. 109, 2245 (2011)], 10.1080/00268976.2011.609142 enabled us to derive a semi-experimental equilibrium structure for fluoroiodomethane by means of a least-squares fit procedure using the available experimental ground-state rotational constants together with computed vibrational corrections. Problems related to the missing isotopic substitution of fluorine and iodine were overcome thanks to the availability of an accurate theoretical equilibrium geometry (computed at the coupled-cluster singles and doubles level augmented by a perturbative treatment of triple excitations).

  11. NUSAT 1 attitude determination

    NASA Technical Reports Server (NTRS)

    Talaga, Paul

    1987-01-01

    This paper presents the methods for attitude determination using the static wide angle field of view sensors of NUSAT 1. Some supporting analysis and operational results are given. The system gives at best a crude attitude determination.

  12. Rethinking the Category 'Determiner'

    ERIC Educational Resources Information Center

    Spangler, Wayne E.

    1975-01-01

    The 'determiner' category was originally set up by structuralists for identifying nouns. The rewrite rule for 'determiners' in transformational generative grammar is inadequate for showing correspondences between type and token. An appraisal of quantity terms might eliminate the concept of the 'determiner,' and replace that category with one of…

  13. Neutron scattering studies in the actinide region. Progress report, August 1, 1988--July 31, 1991

    SciTech Connect

    Beghian, L.E.; Kegel, G.H.R.

    1991-08-01

    During the report period we have investigated the following areas: Neutron elastic and inelastic scattering measurements on {sup 14}N, {sup 181}Ta, {sup 232}Th, {sup 238}U and {sup 239}Pu; Prompt fission spectra for {sup 232}Th, {sup 235}U, {sup 238}U and {sup 239}Pu; Theoretical studies of neutron scattering; Neutron filters; New detector systems; and Upgrading of neutron target assembly, data acquisition system, and accelerator/beam-line apparatus.

  14. Neutron scattering studies in the actinide region

    SciTech Connect

    Beghian, L.E.; Kegel, G.H.R.

    1991-08-01

    During the report period we have investigated the following areas: Neutron elastic and inelastic scattering measurements on {sup 14}N, {sup 181}Ta, {sup 232}Th, {sup 238}U and {sup 239}Pu; Prompt fission spectra for {sup 232}Th, {sup 235}U, {sup 238}U and {sup 239}Pu; Theoretical studies of neutron scattering; Neutron filters; New detector systems; and Upgrading of neutron target assembly, data acquisition system, and accelerator/beam-line apparatus.

  15. Evaluating criticality safety of TRU waste with NDA measurements and risk analyses

    SciTech Connect

    Hochel, R.C.; Hofstetter, K.J.; Sigg, R.A.; Winn, W.G.; Chay, S.C.

    1994-09-01

    The criticality safety of {sup 239}Pu in 55-gal. drums stored in TRU waste containers (concrete culverts) was evaluated using NDA neutron and gamma measurements and risk analyses. The neutron measurements yielded a {sup 239}Pu mass and k{sub eff} for a culvert, which contains up to 14 drums. The gamma measurements helped reveal and correct for any interfering neutron sources in the waste. Conservation probabilistic risk analyses were developed for both drums and culverts.

  16. Nephelometric determination of fluorine

    USGS Publications Warehouse

    Stevens, R.E.

    1936-01-01

    Fluorine in minerals may be determined with the nephelometer to about 1 per cent of the fluorine. The determination is made on an aliquot of the sodium chloride solution of the fluorine, obtained by the Berzelius method of extraction. The fluorine is precipitated as colloidal calcium fluoride in alcoholic solution, gelatin serving as a protective colloid. Arsenates, sulfates, and phosphates, which interfere with the determination, must be removed.

  17. Plutonium excretion in urine of residents living near the Rocky Flats Environmental Technology Site.

    PubMed

    Ibrahim, S A; Whicker, F W; Reuss, S K; Whicker, R D; Chapman, P L; Krahenbuhl, M P

    1999-04-01

    An assessment of current levels of 239Pu in individuals living near the Rocky Flats Environmental Technology Site was conducted. Long-term residents of areas adjacent to the Site, as well as people living well beyond any expected influence of the site, provided urine samples, which were analyzed by fission track analysis for the levels of 239Pu. The Rocky Flats Environmental Technology Site vicinity participants were selected for maximum possible exposure to environmental plutonium by virtue of residence location, length of residence, age, and outdoor lifestyle. The mean 239Pu excretion rate in urine estimated for the entire Rocky Flats group was 1.1 microBq d(-1), in contrast to that estimated for the background group (0.85 microBq d(-1)). The estimated median 239Pu excretion rate for the Rocky Flats group was 1.1 microBq d(-1), compared to 0.54 microBq d(-1) for the background group. Both parametric and non-parametric tests indicated that these differences were not statistically significant (alpha = 0.05). Measured levels of 239Pu in urine from the Rocky Flats group were low and well within the range of reported "background" values, indicating small doses and low health risks. The fission track analysis technique may not be sufficiently accurate or precise to allow definitive comparisons between two groups of subjects with near-background levels of 239Pu in urine. PMID:10086597

  18. Plutonium isotope ratio variations in North America

    SciTech Connect

    Steiner, Robert E; La Mont, Stephen P; Eisele, William F; Fresquez, Philip R; Mc Naughton, Michael; Whicker, Jeffrey J

    2010-12-14

    Historically, approximately 12,000 TBq of plutonium was distributed throughout the global biosphere by thermo nuclear weapons testing. The resultant global plutonium fallout is a complex mixture whose {sup 240}Pu/{sup 239}Pu atom ratio is a function of the design and yield of the devices tested. The average {sup 240}Pu/{sup 239}Pu atom ratio in global fallout is 0.176 + 014. However, the {sup 240}Pu/{sup 239}Pu atom ratio at any location may differ significantly from 0.176. Plutonium has also been released by discharges and accidents associated with the commercial and weapons related nuclear industries. At many locations contributions from this plutonium significantly alters the {sup 240}Pu/{sup 239}Pu atom ratios from those observed in global fallout. We have measured the {sup 240}Pu/{sup 239}Pu atom ratios in environmental samples collected from many locations in North America. This presentation will summarize the analytical results from these measurements. Special emphasis will be placed on interpretation of the significance of the {sup 240}Pu/{sup 239}Pu atom ratios measured in environmental samples collected in the Arctic and in the western portions of the United States.

  19. Sex Determination in Papaya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex determination is an intriguing system in trioecious papaya. Over the past seven decades various hypotheses, based on the knowledge and information available at the time, have been proposed to explain the genetics of the papaya's sex determination. These include a single gene with three alleles...

  20. Determinants of Education Achievement.

    ERIC Educational Resources Information Center

    Lave, Charles; And Others

    1981-01-01

    A model is tested of the determinants of educational attainment among peasants on Mexico's Yucatan Peninsula, involving family background, personal characteristics (including IQ), and years of schooling available. Results indicate that the model explains much of the variance in educational attainment, and that IQ is only a minor determinant. (RW)

  1. Spacecraft Attitude Determination Methods

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2000-01-01

    This document is presentation in viewgraph form, which outlines the methods of determining spacecraft attitude. The presentation reviews several parameterizations relating to spacecraft attitude, such as Euler's Theorem, Rodriques parameters, and Euler-Rodriques parameters or Quaternion. Onboard attitude determination is the norm, using either single frame or filtering methods. The presentation reviews several mathematical representations of attitude. The mechanisms for determining attitude on board the Hubble Space Telescope, the Tropical Rainfall and Measuring Mission and the Solar Anomalous and Magnetospheric Particle Explorer are reviewed. Wahba's problem, Procrustes Problem, and some solutions are also summarized.

  2. Temperature determination using pyrometry

    DOEpatents

    Breiland, William G.; Gurary, Alexander I.; Boguslavskiy, Vadim

    2002-01-01

    A method for determining the temperature of a surface upon which a coating is grown using optical pyrometry by correcting Kirchhoff's law for errors in the emissivity or reflectance measurements associated with the growth of the coating and subsequent changes in the surface thermal emission and heat transfer characteristics. By a calibration process that can be carried out in situ in the chamber where the coating process occurs, an error calibration parameter can be determined that allows more precise determination of the temperature of the surface using optical pyrometry systems. The calibration process needs only to be carried out when the physical characteristics of the coating chamber change.

  3. Ultrasonic material property determinations

    NASA Technical Reports Server (NTRS)

    Serabian, S.

    1986-01-01

    The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries are presented.

  4. Protein Nitrogen Determination

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    The protein content of foods can be determined by numerous methods. The Kjeldahl method and the nitrogen combustion (Dumas) method for protein analysis are based on nitrogen determination. Both methods are official for the purposes of nutrition labeling of foods. While the Kjeldahl method has been used widely for over a hundred years, the recent availability of automated instrumentation for the Dumas method in many cases is replacing use of the Kjeldahl method.

  5. Determining postural stability

    NASA Technical Reports Server (NTRS)

    Lieberman, Erez (Inventor); Forth, Katharine E. (Inventor); Paloski, William H. (Inventor)

    2011-01-01

    A method for determining postural stability of a person can include acquiring a plurality of pressure data points over a period of time from at least one pressure sensor. The method can also include the step of identifying a postural state for each pressure data point to generate a plurality of postural states. The method can include the step of determining a postural state of the person at a point in time based on at least the plurality of postural states.

  6. Solids mass flow determination

    DOEpatents

    Macko, Joseph E.

    1981-01-01

    Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

  7. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1997-07-01

    A new technique has been developed to determine the age of highly enriched uranium (HEU) in solids. Uranium age is defined as the time since the uranium-containing material was last subjected to a process capable of separating uranium from its radioactive-decay daughters. [Most chemical processing, uranium enrichment, volatilization processes, and phase transformations (especially relevant for uranium hexafluoride) can result in separation of the uranium parent material from the decay-product daughters.] Determination of the uranium age, as defined here, may be relevant in verifying arms-control agreements involving uranium-containing nuclear weapons. The HEU age is determined from the ratios of relevant uranium daughter isotopes and their parents, viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gamma rays and their daughters by alpha spectroscopy. In some of the samples, where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the samples. In this report the methodology and the data for determining the age of two HEU samples are presented.

  8. Determinants of marriage dissolution

    NASA Astrophysics Data System (ADS)

    Rahim, Mohd Amirul Rafiq Abu; Shafie, Siti Aishah Mohd; Hadi, Az'lina Abdul; Razali, Nornadiah Mohd; Azid @ Maarof, Nur Niswah Naslina

    2015-10-01

    Nowadays, the number of divorce cases among Muslim couples is very worrisome whereby the total cases reported in 2013 increased by half of the total cases reported in the previous year. The questions on the true key factors of dissolution of marriage continue to arise. Thus, the objective of this study is to reveal the factors that contribute to the dissolution of marriage. A total of 181 cases and ten potential determinants were included in this study. The potential determinants considered were age at marriage of husband and wife, educational level of husband and wife, employment status of husband and wife, income of husband and wife, the number of children and the presence at a counseling session. Logistic regression analysis was used to analyze the data. The findings revealed that four determinants, namely the income of husband and wife, number of children and the presence at a counselling session were significant in predicting the likelihood of divorce among Muslim couples.

  9. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1995-08-01

    A technique has been developed to determine the Highly Enriched Uranium (HEU) Age which is defined as the time since the HEU was produced in an enrichment process. The HEU age is determined from the ratios of relevant uranium parents and their daughters viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gammas and their daughters by alpha spectroscopy. In some of the samples where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the sample. In this paper we have presented data and methodology of finding the age of two HEU samples.

  10. Ultrasonic determination of recrystallization

    NASA Technical Reports Server (NTRS)

    Generazio, E. R.

    1986-01-01

    Ultrasonic attenuation was measured for cold worked Nickel 200 samples annealed at increasing temperatures. Localized dislocation density variations, crystalline order and colume percent of recrystallized phase were determined over the anneal temperature range using transmission electron microscopy, X-ray diffraction, and metallurgy. The exponent of the frequency dependence of the attenuation was found to be a key variable relating ultrasonic attenuation to the thermal kinetics of the recrystallization process. Identification of this key variable allows for the ultrasonic determination of onset, degree, and completion of recrystallization.

  11. Determinants of project success

    NASA Technical Reports Server (NTRS)

    Murphy, D. C.; Baker, B. N.; Fisher, D.

    1974-01-01

    The interactions of numerous project characteristics, with particular reference to project performance, were studied. Determinants of success are identified along with the accompanying implications for client organization, parent organization, project organization, and future research. Variables are selected which are found to have the greatest impact on project outcome, and the methodology and analytic techniques to be employed in identification of those variables are discussed.

  12. Determination of Offgassed Products

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A technician at Marshall Space Flight Center's Materials Combustion Research Facility begins the Determination of Offgassed Products Test to determine the identity and quantity of volatile offgassed products from materials and assembled articles. Materials are measured, weighed, and loaded into a clean toxicity chamber (pictured). The chamber is purged with high-purity air and loaded into an oven where it will be held at 120 degrees Fahrenheit (48.9 degrees Celsius) for 72 hours. At the end of the 72-hour period, the chamber is removed and allowed to cool to room temperature. Gas samples are taken from the chamber and analyzed using gas chromatography and mass spectrometry. From this, the quantity of the material that may be used safely in habitable areas of spacecraft is determined. This test also determines whether a flight hardware item may be flown safely in a crew compartment. Everything going into space with the astronauts is tested prior to flight to ensure the health and safety of the crew members.

  13. Determining TOC in Waters

    ERIC Educational Resources Information Center

    Kehoe, Thomas J.

    1977-01-01

    The instrumental method for detecting total organic carbon (TOC) in water samples is detailed. The method's limitations are discussed and certain precautions that must be taken are emphasized. The subject of TOC versus COD and BOD is investigated and TOC is determined to be a valid indication of biological demand. (BT)

  14. Gender determination in populus

    SciTech Connect

    McLetchie, D.N.; Tuskan, G.A.

    1994-12-31

    Gender, the expression of maleness or femaleness, in dioecious plants has been associated with changes in morphology, physiology, ecological position, and commercial importance of several species, including members of the Salicaceae family. Various mechanisms have been proposed to explain the expression of gender in Salicaceae, including sex chromosomes, simple Mendelian genes, quantitative genes, environment, and genotype-by-environment interactions. Published reports would favor a genetic basis for gender. The objective of this study was to identify molecular markers associated with gender in a segregating family of hybrid poplars. Bulked segregant analysis and chi-squared analysis were used to test for the occurrence of sex chromosomes, individual loci, and chromosome ratios (i.e., ploidy levels) as the mechanisms for gender determination. Examination of 2488 PCR based RAPD markers from 1219 primers revealed nine polymorphic bands between male and female bulked samples. However, linkage analysis indicated that none of these markers were significantly associated with gender. Chisquared results for difference in male-to-female ratios between diploid and triploid genotypes also revealed no significant differences. These findings suggest gender is not controlled via sex chromosomes, simple Mendelian loci or ratios of autosome to gender-determining loci. It is possible that gender is determined genetically by regions of the genome not sampled by the tested markers or by a complex of loci operating in an additive threshold manner or in an epistatic manner. It is also possible that gender is determined environmentally at an early zygote stage, canalizing gender expression.

  15. Determination of Fat Content

    NASA Astrophysics Data System (ADS)

    Carpenter, Charles

    The term "lipid" refers to a group of compounds that are sparingly soluble in water, but show variable solubility in a number of organic solvents (e.g., ethyl ether, petroleum ether, acetone, ethanol, methanol, benzene). The lipid content of a food determined by extraction with one solvent may be quite different from the lipid content as determined with another solvent of different polarity. Fat content is determined often by solvent extraction methods (e.g., Soxhlet, Goldfish, Mojonnier), but it also can be determined by nonsolvent wet extraction methods (e.g., Babcock, Gerber), and by instrumental methods that rely on the physical and chemical properties of lipids (e.g., infrared, density, X-ray absorption). The method of choice depends on a variety of factors, including the nature of the sample (e.g., dry versus moist), the purpose of the analysis (e.g., official nutrition labeling or rapid quality control), and instrumentation available (e.g., Babcock uses simple glassware and equipment; infrared requires an expensive instrument).

  16. Determining Haugh Units

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapidly determining shell egg quality in an objective manner is not an easy task. Candling is most often utilized as a quick method for assessing egg quality in a non-destructive manner, but it is a highly subjective method. As you have experienced this week, it is almost impossible for multiple p...

  17. Waste Determination Equivalency - 12172

    SciTech Connect

    Freeman, Rebecca D.

    2012-07-01

    The Savannah River Site (SRS) is a Department of Energy (DOE) facility encompassing approximately 800 square kilometers near Aiken, South Carolina which began operations in the 1950's with the mission to produce nuclear materials. The SRS contains fifty-one tanks (2 stabilized, 49 yet to be closed) distributed between two liquid radioactive waste storage facilities at SRS containing carbon steel underground tanks with storage capacities ranging from 2,800,000 to 4,900,000 liters. Treatment of the liquid waste from these tanks is essential both to closing older tanks and to maintaining space needed to treat the waste that is eventually vitrified or disposed of onsite. Section 3116 of the Ronald W. Reagan National Defense Authorization Act of Fiscal Year 2005 (NDAA) provides the Secretary of Energy, in consultation with the Nuclear Regulatory Commission (NRC), a methodology to determine that certain waste resulting from prior reprocessing of spent nuclear fuel are not high-level radioactive waste if it can be demonstrated that the waste meets the criteria set forth in Section 3116(a) of the NDAA. The Secretary of Energy, in consultation with the NRC, signed a determination in January 2006, pursuant to Section 3116(a) of the NDAA, for salt waste disposal at the SRS Saltstone Disposal Facility. This determination is based, in part, on the Basis for Section 3116 Determination for Salt Waste Disposal at the Savannah River Site and supporting references, a document that describes the planned methods of liquid waste treatment and the resulting waste streams. The document provides descriptions of the proposed methods for processing salt waste, dividing them into 'Interim Salt Processing' and later processing through the Salt Waste Processing Facility (SWPF). Interim Salt Processing is separated into Deliquification, Dissolution, and Adjustment (DDA) and Actinide Removal Process/Caustic Side Solvent Extraction Unit (ARP/MCU). The Waste Determination was signed by the

  18. Determination of nickel-63

    SciTech Connect

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample.

  19. Stepwise shockwave velocity determinator

    NASA Technical Reports Server (NTRS)

    Roth, Timothy E.; Beeson, Harold

    1992-01-01

    To provide an uncomplicated and inexpensive method for measuring the far-field velocity of a surface shockwave produced by an explosion, a stepwise shockwave velocity determinator (SSVD) was developed. The velocity determinator is constructed of readily available materials and works on the principle of breaking discrete sensors composed of aluminum foil contacts. The discrete sensors have an average breaking threshold of approximately 7 kPa. An incremental output step of 250 mV is created with each foil contact breakage and is logged by analog-to-digital instrumentation. Velocity data obtained from the SSVD is within approximately 11 percent of the calculated surface shockwave velocity of a muzzle blast from a 30.06 rifle.

  20. Determination of balloon drag

    NASA Technical Reports Server (NTRS)

    Conrad, George R.; Robbins, Edward J.

    1991-01-01

    The evolution of an empirical drag relationship that has stimulated rethinking regarding the physics of balloon drag phenomena is discussed. Combined parasitic drag from all sources in the balloon system are estimated to constitute less than 10 percent of the total system drag. It is shown that the difference between flight-determined drag coefficients and those based on the spherical assumption should be related to the square of the Froude number.

  1. REDUCED PROTECTIVE CLOTHING DETERMINATIONS

    SciTech Connect

    BROWN, R.L.

    2003-06-13

    This technical basis document defines conditions where reduced protective clothing can be allowed, defines reduced protective clothing, and documents the regulatory review that determines the process is compliant with the Tank Farm Radiological Control Manual (TFRCM) and Title 10, Part 835, of the Code of Federal Regulations (10CFR835). The criteria, standards, and requirements contained in this document apply only to Tank Farm Contractor (TFC) facilities.

  2. Gender determination using cheiloscopy

    PubMed Central

    Padmavathi, B. N.; Makkad, Ramanpal Singh; Rajan, S. Y.; Kolli, Gopi Krishna

    2013-01-01

    Background: Although lip prints have been used as an evidence for human identification in forensic science, there exists a doubt about its role in gender determination. Aims: The present study was designed for documenting common patterns, as well as their variation in the study population, with objective of evaluating uniqueness of the lip print pattern among the study population, as well as to evaluate the possibility of gender determination. Study Design: Two hundred and thirty five lip prints were collected from volunteers among out patients of Darshan Dental College and Hospital, as well as community dental care camps of rural areas around Udaipur. Materials and Methods: Lip prints were recorded with transparent overlay and transferred on to a bond paper. It was then photographed using a Canon EOS 55OD 16 mega pixel digital camera. Software Picasa 3.6 and Microsoft Picture Manager were used to digitally enhance the quality and magnify the image bearing the groove pattern. Lip prints were later analyzed. Statistical Analysis: Pearson chi square test was adopted for statistical analysis and probability (P value) was calculated. Conclusion: In our study, none of the lip prints were identical, thus confirming the role of lip prints in individual identification. Dots, reticular and complex patterns were significant in gender determination. PMID:24255561

  3. Multimedia contaminant environmental exposure assessment methodology as applied to Los Alamos, New Mexico

    SciTech Connect

    Whelan, G.; Thompson, F.L.; Yabusaki, S.B.

    1983-02-01

    The MCEA (Multimedia Contaminant Environmental Exposure Assessment) methodology assesses exposures to air, water, soil, and plants from contaminants released into the environment by simulating dominant mechanisms of contaminant migration and fate. The methodology encompasses five different pathways (i.e., atmospheric, terrestrial, overland, subsurface, and surface water) and combines them into a highly flexible tool. The flexibility of the MCEA methodology is demonstrated by encompassing two of the pathways (i.e., overland and surface water) into an effective tool for simulating the migration and fate of radionuclides released into the Los Alamos, New Mexico region. The study revealed that: (a) the /sup 239/Pu inventory in lower Los Alamos Canyon increased by approximately 1.1 times for the 50-y flood event; (b) the average contaminant /sup 239/Pu concentrations (i.e., weighted according to the depth of the respective bed layer) in lower Los Alamos Canyon for the 50-y flood event decreased by 5.4%; (c) approx. 27% of the total /sup 239/Pu contamination resuspended from the entire bed (based on the assumed cross sections) for the 50-y flood event originated from lower Pueblo Canyon; (d) an increase in the /sup 239/Pu contamination of the bed followed the general deposition patterns experienced by the sediment in Pueblo-lower Los Alamos Canyon; likewise, a decrease in the /sup 239/Pu contamination of the bed followed general sediment resuspension patterns in the canyon; (e) 55% of the /sup 239/Pu reaching the San Ildefonso Pueblo in lower Los Alamos Canyon originated from lower Los Alamos Canyon; and (f) 56% of the /sup 239/Pu contamination reaching the San Ildefonso Pueblo in lower Los Alamos Canyon was carried through towards the Rio Grande. 47 references, 41 figures, 29 tables.

  4. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1994-12-31

    A criteria that a sample of highly enriched uranium (HEU) had come from a weapons stockpile and not newly produced in an enrichment plant is to show that the HEU had been produced a significant time in the past. The time since the HEU has produced in an enrichment plant is defined as the age of the HEU in this paper. The HEU age is determined by measuring quantitatively the daughter products {sup 230}Th and {sup 231}Pa of {sup 234}U and {sup 235}U, respectively, by first chemical separation of the thorium and protactinium and then conducting alpha spectrometry of the daughter products.

  5. Mass determination of neutrinos

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1988-01-01

    A time-energy correlation method has been developed to determine the signature of a nonzero neutrino mass in a small sample of neutrinos detected from a distant source. The method is applied to the Kamiokande II (Hirata et al., 1987) and IMB (Bionta et al., 1987) observations of neutrino bursts from SN 1987A. Using the Kamiokande II data, the neutrino rest mass is estimated at 2.8 + 2.0, - 1.4 eV and the initial neutrino pulse is found to be less than 0.3 sec full width, followed by an emission tail lasting at least 10 sec.

  6. The Determination of Downwash

    NASA Technical Reports Server (NTRS)

    Diehl, Walter S

    1921-01-01

    It is obvious that, in accordance with Newton's second law, the lift on an aerofoil must be equal to the vertical momentum communicated per second to the air mass affected. Consequently a lifting aerofoil in flight is trailed by a wash which has a definite inclination corresponding to the factors producing the lift. It is thought that sufficient data, theoretical and experimental, are now available for a complete determination of this wash with respect to the variation of its angle of inclination to the originating aerofoil and with respect to the law which governs its decay in space.

  7. Determining residential firewood consumption

    NASA Astrophysics Data System (ADS)

    Marsinko, Allan P. C.; Phillips, Douglas R.; Cordell, H. Ken

    1984-07-01

    Household firewood use has become increasingly popular in the United States over the past few years. Significant problems remain in estimating firewood consumption. Methods of determining the amount of wood consumed vary from state to state. Units used for measuring firewood vary, but the cord remains the researcher's favorite. Factors used for converting other units, such as pickup truck loads to cords also vary. People who do not use firewood are less likely to respond to mailed surveys, resulting in potential overestimates of statewide consumption. This paper identifies some problems associated with estimating household firewood consumption and recommends methods of dealing with them.

  8. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1972-01-01

    Satellite altitude determination uncertainties will be discussed from the standpoint of the GEOS-C satellite, from the longer range viewpoint afforded by the Geopause concept. Data are focused on methods for short-arc tracking which are essentially geometric in nature. One uses combinations of lasers and collocated cameras. The other method relies only on lasers, using three or more to obtain the position fix. Two typical locales are looked at, the Caribbean area, and a region associated with tracking sites at Goddard, Bermuda and Canada which encompasses a portion of the Gulf Stream in which meanders develop.

  9. Preparation and characterization of {sup 238}Pu-ceramics for radiation damage experiments

    SciTech Connect

    DM Strachan; RD Scheele; WC Buchmiller; JD Vienna; RL Sell; RJ Elovich

    2000-06-15

    As a result of treaty agreements between Russia and the US, portions of their respective plutonium and nuclear weapons stockpiles have been declared excess. In support of the US Department of Energy's 1998 decision to pursue immobilization of a portion of the remaining Pu in a titanate-based ceramic, the authors prepared nearly 200 radiation-damage test specimens of five Pu- and {sup 238}Pu-ceramics containing 10 mass% Pu to determine the effects of irradiation from the contained Pu and U on the ceramic. The five Pu-ceramics were (1) phase-pure pyrochlore [ideally, Ca(U, Pu)Ti{sub 2}O{sub 7}], (2) pyrochlore-rich baseline, (3) pyrochlore-rich baseline with impurities, (4) phase-pure zirconolite [ideally Ca(U, Pu)Ti{sub 2}O{sub 7}], and (5) a zirconolite-rich baseline. These ceramics were prepared with either normal weapons-grade Pu, which is predominantly {sup 239}Pu, or {sup 238}Pu. The {sup 238}Pu accelerates the radiation damage relative to the {sup 239}Pu because of its much higher specific activity. The authors were unsuccessful in preparing phase-pure (Pu, U) brannerite, which is the third crystalline phase present in the baseline immobilization form. Since these materials will contain {approximately}10 mass% Pu and about 20 mass% U, radiation damage to the crystalline structure of these materials will occur overtime. As the material becomes damaged from the decay of the Pu and U, it is possible for the material to swell as both the alpha particles and recoiling atoms rupture chemical bonds within the solid. As the material changes density, cracking, perhaps in the form of microcracks, may occur. If cracking occurs in ceramic that has been placed in a repository, the calculated rate of radionuclide release if the can has corroded would increase proportionately to the increase in surface area. To investigate the effects of radiation damage on the five ceramics prepared, the authors are storing the specimens at 20, 125, and 250 C until the {sup 238}Pu specimens

  10. Determination of radar MTF

    SciTech Connect

    Chambers, D.

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  11. Determination of Survivable Fires

    NASA Technical Reports Server (NTRS)

    Dietrich, D. L.; Niehaus, J. E.; Ruff, G. A.; Urban, D. L.; Takahashi, F.; Easton, J. W.; Abbott, A. A.; Graf, J. C.

    2012-01-01

    At NASA, there exists no standardized design or testing protocol for spacecraft fire suppression systems (either handheld or total flooding designs). An extinguisher's efficacy in safely suppressing any reasonable or conceivable fire is the primary benchmark. That concept, however, leads to the question of what a reasonable or conceivable fire is. While there exists the temptation to over-size' the fire extinguisher, weight and volume considerations on spacecraft will always (justifiably) push for the minimum size extinguisher required. This paper attempts to address the question of extinguisher size by examining how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or other accumulation of other combustion products (e.g. carbon monoxide). Estimates of these quantities are determined as a function of fire size and mass of material burned. This then becomes the basis for determining the maximum size of a target fire for future fire extinguisher testing.

  12. Satellite orbit determination

    NASA Technical Reports Server (NTRS)

    Jordan, J. F.; Boggs, D. H.; Born, G. H.; Christensen, E. J.; Ferrari, A. J.; Green, D. W.; Hylkema, R. K.; Mohan, S. N.; Reinbold, S. J.; Sievers, G. L.

    1973-01-01

    A historic account of the activities of the Satellite OD Group during the MM'71 mission is given along with an assessment of the accuracy of the determined orbit of the Mariner 9 spacecraft. Preflight study results are reviewed, and the major error sources described. Tracking and data fitting strategy actually used in the real time operations is itemized, and Deep Space Network data available for orbit fitting during the mission and the auxiliary information used by the navigation team are described. A detailed orbit fitting history of the first four revolutions of the satellite orbit of Mariner 9 is presented, with emphasis on the convergence problems and the delivered solution for the first orbit trim maneuver. Also included are a solution accuracy summary, the history of the spacecraft orbit osculating elements, the results of verifying the radio solutions with TV imaging data, and a summary of the normal points generated for the relativity experiment.

  13. Determination of Cytotoxicity.

    PubMed

    2016-01-01

    Cytotoxicity assays are used for drug screening and cytotoxicity tests of chemicals. Nowadays, various reagents are used for cell viability detection. They are based on various cell functions such as enzyme activity, cell membrane permeability, cell adherence, ATP production, co-enzyme production and nucleotide uptake activity. Many have established methods such as colony formation method, crystal violet method, tritium-labelled thymidine uptake method, MTT and WST methods, which are used for counting the number of live cells. Moreover, trypan blue is a widely used assay for staining dead cells. In this method, cell viability must be determined by counting the unstained cells with a microscope or other instruments. This chapter is a collection of all these methods to be followed by researchers in a sequential manner. PMID:26939283

  14. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1971-01-01

    Satellite altitude determination uncertainties are discussed from the standpoint of the GEOS-C satellite. GEOS-C will be tracked by a number of the conventional satellite tracking systems, as well as by two advanced systems; a satellite-to-satellite tracking system and lasers capable of decimeter accuracies which are being developed in connection with the Goddard Earth and Ocean Dynamics Applications program. The discussion is organized in terms of a specific type of GEOS-C orbit which would satisfy a number of scientific objectives including the study of the gravitational field by means of both the altimeter and the satellite-to-satellite tracking system, studies of tides, and the Gulf Stream meanders.

  15. Determinants of genetic diversity.

    PubMed

    Ellegren, Hans; Galtier, Nicolas

    2016-07-01

    Genetic polymorphism varies among species and within genomes, and has important implications for the evolution and conservation of species. The determinants of this variation have been poorly understood, but population genomic data from a wide range of organisms now make it possible to delineate the underlying evolutionary processes, notably how variation in the effective population size (Ne) governs genetic diversity. Comparative population genomics is on its way to providing a solution to 'Lewontin's paradox' - the discrepancy between the many orders of magnitude of variation in population size and the much narrower distribution of diversity levels. It seems that linked selection plays an important part both in the overall genetic diversity of a species and in the variation in diversity within the genome. Genetic diversity also seems to be predictable from the life history of a species. PMID:27265362

  16. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-07-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanisms, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  17. Complexometric Determination of Calcium

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are such indicators that change from blue to pink when they complex with calcium and magnesium. In the titration of a mineral-containing solution with EDTA, the solution turns from pink to blue at the endpoint with either indicator. The pH affects a complexometric EDTA titration in several ways, and must be carefully controlled. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one (Standard Methods for the Examination of Water and Wastewater, Method 2340C; AOAC Method 920.196).

  18. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-04-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanims, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  19. Tracer for circulation determinations

    SciTech Connect

    Moore, H.; Santos, S.; Wysong, R. D.

    1985-03-19

    An improved tracer particle is described comprising an ion exchange core having a polymer coating thereon, the coated ion exchange core having a reaction site capable of reacting with a compound containing an oxirane group, said coated ion exchange core having been treated with a compound containing an oxirane group to react with said coated ion exchange core causing an increase in mass of the tracer particle. Preferably, the ion exchange core is labelled with a radionuclide. These particles have improved characteristics including improved stability against leaching and improved handling properties. Such particles are useful in circulatory determinations involving the injection of the particles as a suspension in a physiologically acceptable carrier or medium into the circulatory system of animals.

  20. Orbit Determination Toolbox

    NASA Technical Reports Server (NTRS)

    Carpenter, James R.; Berry, Kevin; Gregpru. Late; Speckman, Keith; Hur-Diaz, Sun; Surka, Derek; Gaylor, Dave

    2010-01-01

    The Orbit Determination Toolbox is an orbit determination (OD) analysis tool based on MATLAB and Java that provides a flexible way to do early mission analysis. The toolbox is primarily intended for advanced mission analysis such as might be performed in concept exploration, proposal, early design phase, or rapid design center environments. The emphasis is on flexibility, but it has enough fidelity to produce credible results. Insight into all flight dynamics source code is provided. MATLAB is the primary user interface and is used for piecing together measurement and dynamic models. The Java Astrodynamics Toolbox is used as an engine for things that might be slow or inefficient in MATLAB, such as high-fidelity trajectory propagation, lunar and planetary ephemeris look-ups, precession, nutation, polar motion calculations, ephemeris file parsing, and the like. The primary analysis functions are sequential filter/smoother and batch least-squares commands that incorporate Monte-Carlo data simulation, linear covariance analysis, measurement processing, and plotting capabilities at the generic level. These functions have a user interface that is based on that of the MATLAB ODE suite. To perform a specific analysis, users write MATLAB functions that implement truth and design system models. The user provides his or her models as inputs to the filter commands. The software provides a capability to publish and subscribe to a software bus that is compliant with the NASA Goddard Mission Services Evolution Center (GMSEC) standards, to exchange data with other flight dynamics tools to simplify the flight dynamics design cycle. Using the publish and subscribe approach allows for analysts in a rapid design center environment to seamlessly incorporate changes in spacecraft and mission design into navigation analysis and vice versa.

  1. Significant Radionuclides Determination

    SciTech Connect

    Jo A. Ziegler

    2001-07-31

    The purpose of this calculation is to identify radionuclides that are significant to offsite doses from potential preclosure events for spent nuclear fuel (SNF) and high-level radioactive waste expected to be received at the potential Monitored Geologic Repository (MGR). In this calculation, high-level radioactive waste is included in references to DOE SNF. A previous document, ''DOE SNF DBE Offsite Dose Calculations'' (CRWMS M&O 1999b), calculated the source terms and offsite doses for Department of Energy (DOE) and Naval SNF for use in design basis event analyses. This calculation reproduces only DOE SNF work (i.e., no naval SNF work is included in this calculation) created in ''DOE SNF DBE Offsite Dose Calculations'' and expands the calculation to include DOE SNF expected to produce a high dose consequence (even though the quantity of the SNF is expected to be small) and SNF owned by commercial nuclear power producers. The calculation does not address any specific off-normal/DBE event scenarios for receiving, handling, or packaging of SNF. The results of this calculation are developed for comparative analysis to establish the important radionuclides and do not represent the final source terms to be used for license application. This calculation will be used as input to preclosure safety analyses and is performed in accordance with procedure AP-3.12Q, ''Calculations'', and is subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (DOE 2000) as determined by the activity evaluation contained in ''Technical Work Plan for: Preclosure Safety Analysis, TWP-MGR-SE-000010'' (CRWMS M&O 2000b) in accordance with procedure AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''.

  2. Determining satellite close approaches

    NASA Astrophysics Data System (ADS)

    Alfano, Salvatore; Negron, David, Jr.

    1993-06-01

    This paper presents a numerical method to evaluate close approaches of two satellites. The algorithm is based on a space curve modeling technique originally developed by Overhauser, presented here as an independent derivation. The method to determine minimum spacing between two space objects is based on creating a relative distance waveform, delta(t), versus time. The waveform is produced from either uniform or arbitrarily spaced data points, from which intervals of close approach are obtained by extracting the real roots of a localized cubic polynomial. This method is free of both transcendental equations and the computation of acceleration terms of the two objects of interest. For this study, a close approach truth table is constructed using a 0.1 second sequential step along the orbits, then differencing the two position vectors. The close approach entrance and exit times for an ellipsoidal quadric surface are then located using a piecewise linear interpolator, and serve as a benchmark for comparison. The simulation results show this algorithm produces encounter times almost identical to those in the truth table, with a 99.84 percent reduction in computer runtime. The results, created from real orbital data, include solution sets for three operational uses of close-approach logic. For this study, satellite orbital motion is modeled using first-order secular perturbations caused by mass anomalies.

  3. Age determination of raccoons

    USGS Publications Warehouse

    Grau, G.A.; Sanderson, G.C.; Rogers, J.P.

    1970-01-01

    Age criteria, based on 61 skulls and eye lenses from 103 known-age captives, are described for separating raccoons (Procyon lotor) into eight age-classes as follows: young-of-the-year, 1, 2, 3, 4, 5, 6-7, > 7 years. Criteria studied were eye lens nitrogen, cranial suture closure, tooth wear and incisor cementum layers. Lens nitrogen increased rapidly up to 12 months of age, but at much reduced rate thereafter. Total lens nitrogen was useful only in separating young-of-the-year from adults. The closure sequence for five cranial sutures accurately divided the total known-age sample of males into seven groups, and the adults into five groups. The tooth wear criteria divided the known-age sample into five relative age groups, but aging of individuals by this method was inaccurate. Histological sectioning of known-age teeth was the best method of observing layering in the cementum tissue. The technique of basing estimation of age on cementum ring counts, although subjective, was accurate for aging individuals through their fourth year but tended to underestimate the age of animals over 4 years old. However, suture closure or tooth wear can be used to identify males over 4 years old. In field studies, technical difficulties limit the utility of age estimation by cementum layers. Maximum root thickness of the lower canine was accurate in determining the sex of individuals from 5 months to ,at least 48 months of age.

  4. [Influence of Professional Contact with Plutonium-239 on Indicators of the Immune Status of the Personnel at Siberian Chemical Plant].

    PubMed

    Oradovskaya, I V; Radzivil, T T

    2015-01-01

    The results of the examination and monitoring of the personnel at the Siberian Chemical Plant (SChP) and adult population of Seversk are presented. The results of primary examination of the personnel who professionally contact the ionizing radiation (IR) from external sources and incorporated 239Pu showed that clinical symptoms of dysfunction of the immune system manifested themselves with a frequency of 75.30%. Infectious-inflammatory diseases (46.95%) and the combined pathology of infectious and allergic character (20.12%) were the most widespread. The allergic diseases (AD) without manifestations of an infectious component were observed not often (7.62%). The monitoring which was carried out for 10 years revealed a decrease in a percentage of persons with clinical signs of disorders of the immune system up to 60.68% among the personnel at the Chemical-Steel Plant and even more among the whole group of the studied personnel at SChP--49.68% (389 : 783). Among the population their frequency made up 51.78%. Features of clinical manifestations of dysfunction ofthe immune system depending on accumulation of 239Pu in the organism are established. Similar dynamics of infectious and infectious and allergic syndromes is revealed when the activity of 239Pu is 40 nCi. AD frequency reliably increased .when the activity of 239Pu is 20 nCi, but if accumulation is higher than 20-40 nCi it decreases and again increases when the activity is over 40 nCi. Pathologies of infectious and allergic genesis are most often observed when the content of 239Pu in an organism is over 40 nCi. Indicators of the immune status (IS) of the personnel at SChP with incorporated 239Pu are analyzed. 59 people--carriers of 239Pu and 408 people without 239Pu accumulated in an organism are examined. In comparison with the control, IS indicators characteristic for all dose loading groups are revealed: increase of lymphocytes, existence of dissociation in indicators of relative and absolute values of the T

  5. Resolving Chernobyl vs. global fallout contributions in soils from Poland using Plutonium atom ratios measured by inductively coupled plasma mass spectrometry.

    PubMed

    Ketterer, Michael E; Hafer, Kevin M; Mietelski, Jerzy W

    2004-01-01

    Plutonium in Polish forest soils and the Bór za Lasem peat bog is resolved between Chernobyl and global fallout contributions via inductively coupled plasma mass spectrometric measurements of 240Pu/230Pu and 241Pu/239Pu atom ratios in previously prepared NdF3 alpha spectrometric sources. Compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/230Pu and 241Pu/239Pu co-vary and range from 0.186 to 0.348 and 0.0029 to 0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407 x [240Pu/239Pu] - 0.0413; r2 = 0.9924). Two-component mixing models are developed to apportion 239+240Pu and 241Pu activities; various estimates of the percentage of Chernobyl-derived 239+240Pu activity in forest soils range from < 10% to > 90% for the sample set. The 240Pu/230Pu - 241Pu/239Pu atom ratio mixing line extrapolates to estimate 241Pu/239Pu and the 241Pu/239+240Pu activity ratio for the Chernobyl source term (0.123 +/- 0.0007; 83 +/- 5; 1 May 1986). Sample 241Pu activities, calculated using existing alpha spectrometric 239+240Pu activities, and the 240Pu/230Pu and 241Pu/239Pu atom ratios, agree relatively well with previous liquid scintillation spectrometry measurements. Chernobyl Pu is most evident in locations from northeastern Poland. The 241Pu activities and/or the 241Pu/239Pu atom ratios are more sensitive than 240Pu/239Pu or 238Pu/239+240Pu activity ratios at detecting small Chernobyl 239+240Pu inputs, found in southern Poland. The mass spectrometric data show that the 241Pu activity is 40-62% Chernobyl-derived in southern Poland, and 58-96% Chernobyl in northeastern Poland. The Bór za Lasem peat bog (49.42 degrees N, 19.75 degrees E), located in the Orawsko-Nowotarska valley of southern Poland, consists of global fallout Pu. PMID:15023447

  6. Individual Radiological Protection Monitoring of Utrok Atoll Residents Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Bioassay

    SciTech Connect

    Hamilton, T; Kehl, S; Brown, T; Martinelli, R; Hickman, D; Jue, T; Tumey, S; Langston, R

    2007-06-08

    group of people. In general, the results from the whole-body counting measurements of 137Cs are consistent with our knowledge that a key pathway for exposure to residual fallout contamination on Utrok Atoll is low-level chronic uptake of {sup 137}Cs from the consumption of locally grown produce (Robison et al., 1999). The error-weighted, average body burden of {sup 137}Cs measured in Group I and Group II volunteers was 0.31 kBq and 0.62 kBq, respectively. The associated average, annual committed effective dose equivalent (CEDE) delivered to Group I and Group II volunteers from {sup 137}Cs during the year of measurement was 2.1 and 4.0 mrem. For comparative purposes, the annual dose limit for members of the public as recommended by the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP) is 100 mrem. Consequently, specific concerns about elevated levels of {sup 137}Cs uptake and higher risks from radiation exposure to Group I volunteers would be considered unfounded. Moreover, the urinary excretion of plutonium-239 ({sup 239}Pu) from Group I and Group II volunteers is statistically indistinguishable. In this case, the error-weighted, average urinary excretion of {sup 239}Pu from Group I volunteers of 0.10 {mu}Bq per 24-h void with a range between -0.01 and 0.23 {mu}Bq per 24-h void compares with an error-weighted average from Group II volunteers of 0.11 {mu}Bq per 24-h void with a range between -0.20 and 0.47 {mu}Bq per 24-h void. The range in urinary excretion of {sup 239}Pu from Utrok Atoll residents is very similar to that observed for other population groups in the Marshall Islands (Bogen et al., 2006; Hamilton et al., 2006a; 2006b; 2006c, 2007a; 2007b; 2007c) and is generally considered representative of worldwide background.

  7. Criticality assessment of TRU burial ground culverts

    SciTech Connect

    Winn, W.G.

    1990-09-26

    An effort to assess the criticality risks of {sup 239}Pu in TRU Burial Ground Culverts has been underway for several years. The concern arose from discrepancies in two types of monitors that have been used to assay the {sup 239}Pu waste prior to storage in 55-gallon drums that are placed in the culverts. One type is the solid waste monitor (SWM), which is based on gamma-ray measurements; the other is the neutron coincidence monitor, which is based on neutron measurements. The NCC was put into routine service after 1985 and has generally yielded higher 239 Pu assays than the SWM. Culverts with pre-1986 waste only had SWM assays of {sup 239}Pu; thus, it was questioned whether their actual {sup 239}Pu loadings could be high enough to pose criticality concerns. Studies to characterize the culvert criticality potential have included appraisal of NCC vs SWM, neutron measurements atop the culverts, gamma-ray measurements atop the culverts, and probabilistic risk analyses. Overall, these studies have implied that the culverts are critically safe; however, their results have not been examined collectively. The present report uses the collective information of the preceding studies to arrive at a more complete assessment of the culvert criticality aspects. A conservative k{sub eff} is estimated for an individual suspicious culvert and a PRA is evaluated for its {open_quotes}worst{close_quotes} drum. These two pieces of information form the basis of the appraisal, but other evidence is also included as support.

  8. Possible differences in biological availability of isotopes of plutonium: Report of a workshop

    SciTech Connect

    Kercher, J.R.; Gallegos, G.M.

    1993-09-01

    This paper presents the results of a workshop conducted on the apparent different bioavailability of isotopes {sup 238}Pu and {sup 239}Pu. There is a substantial body of evidence that {sup 238}Pu as commonly found in the environment is more biologically available than {sup 239}Pu. Studies of the Trinity Site, Nevada Test Site from nonnuclear and nuclear events, Rocky Flats, Enewetak and Bikini, and the arctic tundra support this conclusion and indicate that the bioavailability of {sup 238}Pu is more than an order of magnitude greater than that of {sup 239}Pu. Plant and soil studies from controlled environments and from Savannah River indicate no isotopic difference in availability of Pu to plants; whereas studies at the Trinity Site do suggest a difference. While it is possible that these observations can be explained by problems in the experimental procedure and analytical techniques, this possibility is remote given the ubiquitous nature of the observations. Studies of solubility of Pu in the stomach contents of cattle grazing at the Nevada Test Site and from fish from Bikini Atoll both found that {sup 238}Pu was more soluble than {sup 239}Pu. Studies of the Los Alamos effluent stream indicate that as particle size decreases, the content of {sup 238}Pu relative to {sup 239}Pu increases.

  9. Radioactive targets for neutron-induced cross section measurements

    SciTech Connect

    Kronenberg, A.; Bond, E. M.; Glover, S. E.; Rundberg, R. S.; Vieira, D. J.; Esch, E. I.; Reifarth, R.; Ullmann, J. L.; Haight, Robert C.; Rochmann, D.

    2004-01-01

    Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T{sub 1/2} = 26 minutes), the samples must be rapidly and repeatedly extracted from its {sup 239}Pu parent. Since {sup 239}Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >10{sup 12}). Once extracted and purified, the {sup 235m}U isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The

  10. Lead Slowing-Down Spectrometry for Spent Fuel Assay: FY12 Status Report

    SciTech Connect

    Warren, Glen A.; Anderson, Kevin K.; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, A.; Haight, R. C.; Harris, Jason; Imel, G. R.; Kulisek, Jonathan A.; O'Donnell, J. M.; Stewart, T.; Weltz, Adam

    2012-10-01

    benchmarking measurements, we continue to improve our understanding of the experimental setup by studying issues such as the effect of room return and impurities in the lead. RPI performed a series of experiments with a fresh fuel pin and various 235U and 239Pu sources. A comparison between simulations and measurements shows significant deviations after 200 µs for both 235U and 239Pu samples, as well as significant deviations at earlier times for the 239Pu sample. The FY2013 effort will shift focus to planning for a Technical Readiness Level 5 demonstration. The primary deliverable for the year will be a plan on how to do this demonstration. The plan will include measurement design, sample acquisition, sample handling, cost estimate, schedule and assumptions. Research will continue on the 4He detector, algorithms development, thorium fission chambers and benchmarking measurements involving sub assemblies of fresh fuel.

  11. DETERMINATION OF CALORIES BY NIR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although NIR spectroscopy has been used to determine energy content of feeds, little is known about the capability of near-infrared (NIR) spectroscopy for the determination of available energy in foods for human consumption. Recent studies have been conducted to determine the utilizable energy in p...

  12. Plutonium and Uranium Atom Ratios and Activity Levels in Cochiti Lake Bottom Sediments Provided by Pueblo de Cochiti

    SciTech Connect

    Gallaher, B.M.; Efurd, D.W.; Rokop, D.J.; Benjamin, T.M.

    1999-05-01

    Historical operations at the Los Alamos National Laboratory have contaminated stream sediments with plutonium and other radionuclides. A small portion of these contaminated sediments has been carried by floods into the Rio Grande drainage system, eventually to be trapped by Cochiti Lake located on Pueblo de Cochiti lands approximately 8 km downstream of the Laboratory. In this study, lake bottom sediment samples provided by the Pueblo de Cochiti were analyzed by thermal ionization mass spectrometry to determine plutonium and uranium activity levels and isotopic atom ratios. This specialized analytical method allows us to take isotopic fingerprints of radionuclides found in the sediment and to determine how much plutonium and uranium came from the Laboratory and how much was deposited by worldwide fallout or is natural. Two distinct types of samples were processed: segments of a continuous vertical core of the entire accumulated sediment sequence and other samples from across the lake bottom at the water/sediment interface. Based on measurement of the {sup 240}Pu/{sup 239}Pu atom ratio, Laboratory-derived plutonium is present in eight of nine samples at the core site. On a depth-weighted basis, approximately one-half of the {sup 239}Pu and {sup 240}Pu came from early operations at the Laboratory; the remaining plutonium came from fallout dispersed by above-ground nuclear tests. In contrast to the core site, the samples from the other locations showed little or no evidence of Laboratory-derived plutonium, with more than 90 percent of the plutonium attributable to fallout. The overall amount of plutonium in all the samples is of the same magnitude as other reservoirs in the region. The net increase in plutonium over upstream reservoirs unaffected by Laboratory activities is a maximum of 0.014 pCi/g or 3.5 times. All of the samples reflect natural uranium compositions. Laboratory-derived uranium is not identifiable, presumably because the sediment contains abundant

  13. A Delayed Neutron Counting System for the Analysis of Special Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Sellers, Madison Theresa

    Nuclear forensic analysis is a modem science that uses numerous analytical techniques to identify and attribute nuclear materials in the event of a nuclear explosion, radiological terrorist attack or the interception of illicit nuclear material smuggling. The Canadian Department of National Defence has participated in recent international exercises that have highlighted the Nation's requirement to develop nuclear forensics expertise, protocol and capabilities, specifically pertaining to the analysis of special nuclear materials (SNM). A delayed neutron counting (DNC) system has been designed and established at the Royal Military College of Canada (RMC) to enhance the Government's SNM analysis capabilities. This analytical technique complements those already at RMC by providing a rapid and non-destructive method for the analysis of the fissile isotopes of both uranium (U) and plutonium (Pu). The SLOWPOKE-2 reactor at RMC produces a predominately thermal neutron flux. These neutrons induce fission in the SNM isotopes 233U, 235U and 239Pu releasing prompt fast neutrons, energy and radioactive fission fragments. Some of these fission fragments undergo beta - decay and subsequently emit neutrons, which can be recorded by an array of sensitive 3He detectors. The significant time period between the fission process and the release of these neutrons results in their identification as 'delayed neutrons'. The recorded neutron spectrum varies with time and the count rate curve is unique to each fissile isotope. In-house software, developed by this project, can analyze this delayed neutron curve and provides the fissile mass in the sample. Extensive characterization of the DNC system has been performed with natural U samples with 235 U content ranging from 2--7 microg. The system efficiency and dead time behaviour determined by the natural uranium sample analyses were validated by depleted uranium samples with similar quantities of 235 U resulting in a typical relative error of

  14. Fissile material measurements using the differential die-away self interrogation technique

    SciTech Connect

    Schear, Melissa A; Menlove, Howard O; Tobin, Stephen J; Evans, Louise G; Lee, S Y

    2010-01-01

    Currently, there is substantial research effort focused on quantifying plutonium (Pu) mass in spent fuel using non-destructive assay (NDA) techniques. Of the several techniques being investigated for this purpose, Differential Die-Away Self-Interrogation (DDSI) is a recently proposed, neutron-based NDA technique capable of quantifying the total fissile content in an assembly. Unlike the conventional Differential Die-Away (DDA) technique, DOSI does not require an external neutron source for sample interrogation, but rather, uses the spontaneous fission neutrons originating from {sup 244}Cm within the spent fuel for self-interrogation. The essence of the technique lies in the time separation between the detection of spontaneous fission neutrons from {sup 244}Cm and the detection of induced fission neutrons at a later time. The DDSI detector design imposes this time separation by optimizing the die-away times ({tau}) of the detector and sample interrogation regions to obtain an early and late neutron distribution respectively. The ratio of the count rates in the late gate to the early gate for singles, doubles, and triples is directly proportional to the fissile content present in the sample, which has already been demonstrated for simplified fuel cases using the Monte Carlo N-Particle eXtended (MCNPX) code. The current work applies the DDSI concept to more complex samples, specifically spent Pressurized Water Reactor (PWR) assemblies with varying isotopics resulting from a range of initial enrichment, bumup, and cooling time. We assess the feasibility of using the late gate to early gate ratio as a reliable indicator of overall fissile mass for a range of assemblies by defining a {sup 239}Pu effective mass which indicates the mass of {sup 239}Pu that would yield the same DDSI signal as the combined mass of major fissile isotopes present in the sample. This work is important for assessing the individual capability of the DDSI instrument in quantifying fissile mass in

  15. Further Investigations of NIST Water Sphere Discrepancies

    SciTech Connect

    Broadhead, B.L.

    2001-01-11

    Measurements have been performed on a family of water spheres at the National Institute of Standards and Technology (NIST) facilities. These measurements are important for criticality safety studies in that, frequently, difficulties have arisen in predicting the reactivity of individually subcritical components assembled in a critical array. It has been postulated that errors in the neutron leakage from individual elements in the array could be responsible for these problems. In these NIST measurements, an accurate determination of the leakage from a fission spectrum, modified by water scattering, is available. Previously, results for 3-, 4-, and 5-in. diam. water-filled spheres, both with and without cadmium covers over the fission chambers, were presented for four fissionable materials: {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu. Results were also given for ''dry'' systems, in which the water spheres were drained of water, with the results corresponding to essentially measurements of unmoderated {sup 252}Cf spontaneous-fission neutrons. The calculated-to-experimental (C/E) values ranged from 0.94 to 1.01 for the dry systems and 0.93 to 1.05 for the wet systems, with experimental uncertainties ranging from 1.5 to 1.9%. These results indicated discrepancies that were clearly outside of the experimental uncertainties, and further investigation was suggested. This work updates the previous calculations with a comparison of the predicted C/E values with ENDF/B-V and ENDF/B-VI transport cross sections. Variations in the predicted C/E values that arise from the use of ENDF/B-V, ENDF/B-VI, ENDL92, and LLLDOS for the response fission cross sections are also tabulated. The use of both a 45-group NIST fission spectrum and a continuous-energy fission spectrum for {sup 252}Cf are evaluated. The use of the generalized-linear-least-squares (GLLSM) procedures to investigate the reported discrepancies in the water sphere results for {sup 235}U, {sup 238}U, {sup 239}Pu

  16. RADIATION-INDUCED DECOMPOSITION OF U(VI) ALTERATION PHASES OF UO2

    SciTech Connect

    S. Utsunomiya; R.C. Ewing

    2005-09-08

    U{sup 6+}-phases are common alteration products of spent nuclear fuel under oxidizing conditions, and they may potentially incorporate actinides, such as long-lived {sup 239}Pu and {sup 237}Np, delaying their transport to the biosphere. In order to evaluate the ballistic effects of {alpha}-decay events on the stability of the U{sup 6+}-phases, we report, for the first time, the results of ion beam irradiations (1.0 MeV Kr{sup 2+}) for six different structures of U{sup 6+}-phases: uranophane, kasolite, boltwoodite, saleeite, carnotite, and liebigite. The target uranyl-minerals were characterized by powder X-ray diffraction and identification confirmed by SAED (selected area electron diffraction) in TEM (transmission electron microscopy). The TEM observation revealed no initial contamination of uraninite in these U{sup 6+} phases. All of the samples were irradiated with in situ TEM observation using 1.0 MeV Kr{sup 2+} in the IVEM (intermediate-voltage electron microscope) at the IVEM-Tandem Facility of Argonne National Laboratory. The ion flux was 6.3 x 10{sup 11} ions/cm{sup 2}/sec. The specimen temperatures during irradiation were 298 and 673 K, respectively. The Kr{sup 2+}-irradiation decomposed the U{sup 6+}-phases to nanocrystals of UO{sub 2} at doses as low as 0.006 dpa. The cumulative doses for the pure U{sup 6+}-phases, e.g., uranophane, at 0.1 and 1 million years (m.y.) are calculated to be 0.009 and 0.09 dpa using SRIM2003. However, with the incorporation of 1 wt.% {sup 239}Pu, the calculated doses reach 0.27 and {approx}1.00 dpa in ten thousand and one hundred thousand years, respectively. Under oxidizing conditions, multiple cycles of radiation-induced decomposition to UO{sub 2} followed by alteration to U{sup 6+}-phases should be further investigated to determine the fate of trace elements that may have been incorporated in the U{sup 6+}-phases.

  17. A multi-radionuclide approach to evaluate the suitability of (239+240)Pu as soil erosion tracer.

    PubMed

    Meusburger, Katrin; Mabit, Lionel; Ketterer, Michael; Park, Ji-Hyung; Sandor, Tarjan; Porto, Paolo; Alewell, Christine

    2016-10-01

    Fallout radionuclides have been used successfully worldwide as tracers for soil erosion, but relatively few studies exploit the full potential of plutonium (Pu) isotopes. Hence, this study aims to explore the suitability of the plutonium isotopes (239)Pu and (240)Pu as a method to assess soil erosion magnitude by comparison to more established fallout radionuclides such as (137)Cs and (210)Pbex. As test area an erosion affected headwater catchment of the Lake Soyang (South Korea) was selected. All three fallout radionuclides confirmed high erosion rates for agricultural sites (>25tha(-1)yr(-1)). Pu isotopes further allowed determining the origin of the fallout. Both (240)Pu/(239)Pu atomic ratios and (239+240)Pu/(137)Cs activity ratios were close to the global fallout ratio. However, the depth profile of the (239+240)Pu/(137)Cs activity ratios in undisturbed sites showed lower ratios in the top soil increments, which might be due to higher migration rates of (239+240)Pu. The activity ratios further indicated preferential transport of (137)Cs from eroded sites (higher ratio compared to the global fallout) to the depositional sites (smaller ratio). As such the (239+240)Pu/(137)Cs activity ratio offered a new approach to parameterize a particle size correction factor that can be applied when both (137)Cs and (239+240)Pu have the same fallout source. Implementing this particle size correction factor in the conversion of (137)Cs inventories resulted in comparable estimates of soil loss for (137)Cs and (239+240)Pu. The comparison among the different fallout radionuclides highlights the suitability of (239+240)Pu through less preferential transport compared to (137)Cs and the possibility to gain information regarding the origin of the fallout. In conclusion, (239+240)Pu is a promising soil erosion tracer, however, since the behaviour i.e. vertical migration in the soil and lateral transport during water erosion was shown to differ from that of (137)Cs, there is a clear

  18. Pulmonary carcinogenesis in the F344 and Wistar rat after inhalation of plutonium dioxide

    SciTech Connect

    Sanders, C.L. |

    1995-11-01

    Pulmonary carcinogenesis was compared in female F344 and Wistar rats after inhalation of high-fired {sup 239}PuO{sub 2}. Plutonium particle aggregation, as determined by quantitative light and scanning electron microscopic autoradiography, was greater for the F344 strain than for the Wistar strain. The median survival times were similar in control and low-dose (0.8-1.0 Gy) groups of both strains, but were significantly decreased in the high-dose (34-37 Gy) groups of both strains. Squamous metaplasia was not found in control or low-dose groups of either strain, but was found in 62-65% of high-dose groups of both strains. Adenomatous metaplasia was considerably higher in control and low-dose groups of F344 rats than in Wistar rats. A total of 87 lung tumors were found in 140 exposed F344 rats and 46 lung tumors in 176 exposed Wistar rats. The incidence of lung tumors in F344 rats was 1.7% in controls, 20% in the low-dose group and 82% in the high-dose group. The incidence of lung tumors in Wistar rats was 0.1% in controls, nil in the low-dose group and 68% in the high-dose group. The median survival times of rats of both strains in the high-dose groups that died with lung tumors were greater compared with rats in these groups that died without lung tumors. In contrast, these differences did not occur among rats in the low-dose groups. The absolute risk was 1900 lung tumors per 10{sup 4} Rat-Gy for F344 rats but about 210 lung tumors per 10{sup 4} Rat-Gy for high-dose groups of both strains. The adenomatous tumor phenotype predominated in the F344 strain, while the squamous tumor phenotype predominated in the Wistar strain. Risk of squamous tumors was similar for both strains. Overall, the F344 strain appears to be more {open_quotes}sensitive{close_quotes} than the Wistar strain to formation of lung tumors at low to moderate doses from inhaled {sup 239}PuO{sub 2}. 31 refs., 1 fig., 7 tabs.

  19. Lead Slowing-Down Spectrometry Time Spectral Analysis for Spent Fuel Assay: FY11 Status Report

    SciTech Connect

    Kulisek, Jonathan A.; Anderson, Kevin K.; Bowyer, Sonya M.; Casella, Andrew M.; Gesh, Christopher J.; Warren, Glen A.

    2011-09-30

    Developing a method for the accurate, direct, and independent assay of the fissile isotopes in bulk materials (such as used fuel) from next-generation domestic nuclear fuel cycles is a goal of the Office of Nuclear Energy, Fuel Cycle R&D, Material Protection and Control Technology (MPACT) Campaign. To meet this goal, MPACT supports a multi-institutional collaboration, of which PNNL is a part, to study the feasibility of Lead Slowing Down Spectroscopy (LSDS). This technique is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic masses in used fuel with an uncertainty considerably lower than the approximately 10% typical of today's confirmatory assay methods. This document is a progress report for FY2011 PNNL analysis and algorithm development. Progress made by PNNL in FY2011 continues to indicate the promise of LSDS analysis and algorithms applied to used fuel. PNNL developed an empirical model based on calibration of the LSDS to responses generated from well-characterized used fuel. The empirical model, which accounts for self-shielding effects using empirical basis vectors calculated from the singular value decomposition (SVD) of a matrix containing the true self-shielding functions of the used fuel assembly models. The potential for the direct and independent assay of the sum of the masses of 239Pu and 241Pu to within approximately 3% over a wide used fuel parameter space was demonstrated. Also, in FY2011, PNNL continued to develop an analytical model. Such efforts included the addition of six more non-fissile absorbers in the analytical shielding function and the non-uniformity of the neutron flux across the LSDS assay chamber. A hybrid analytical-empirical approach was developed to determine the mass of total Pu (sum of the masses of 239Pu, 240Pu, and 241Pu), which is an important quantity in safeguards. Results using this hybrid method were of approximately the same accuracy as the pure

  20. Plutonium age dating reloaded

    NASA Astrophysics Data System (ADS)

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Mayer, Klaus; Prohaska, Thomas

    2014-05-01

    Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

  1. Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

    DOEpatents

    Caldwell, John T.; Kunz, Walter E.; Atencio, James D.

    1984-01-01

    A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U, .sup.235 U and .sup.239 Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as .sup.240 Pu, .sup.244 Cm and .sup.252 Cf, and the spontaneous alpha particle emitter .sup.241 Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether "permanent" low-level burial is appropriate for the waste sample.

  2. Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

    DOEpatents

    Caldwell, J.T.; Kunz, W.E.; Atencio, J.D.

    1982-03-31

    A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify /sup 233/U, /sup 235/U and /sup 239/Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as /sup 240/Pu, /sup 244/Cm and /sup 252/Cf, and the spontaneous alpha particle emitter /sup 241/Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether permanent low-level burial is appropriate for the waste sample.

  3. Effects of particle size and velocity on burial depth of airborne particles in glass fiber filters

    SciTech Connect

    Higby, D.P.

    1984-11-01

    Air sampling for particulate radioactive material involves collecting airborne particles on a filter and then determining the amount of radioactivity collected per unit volume of air drawn through the filter. The amount of radioactivity collected is frequently determined by directly measuring the radiation emitted from the particles collected on the filter. Counting losses caused by the particle becoming buried in the filter matrix may cause concentrations of airborne particulate radioactive materials to be underestimated by as much as 50%. Furthermore, the dose calculation for inhaled radionuclides will also be affected. The present study was designed to evaluate the extent to which particle size and sampling velocity influence burial depth in glass-fiber filters. Aerosols of high-fired /sup 239/PuO/sub 2/ were collected at various sampling velocities on glass-fiber filters. The fraction of alpha counts lost due to burial was determined as the ratio of activity detected by direct alpha count to the quantity determined by photon spectrometry. The results show that burial of airborne particles collected on glass-fiber filters appears to be a weak function of sampling velocity and particle size. Counting losses ranged from 0 to 25%. A correction that assumes losses of 10 to 15% would ensure that the concentration of airborne alpha-emitting radionuclides would not be underestimated when glass-fiber filters are used. 32 references, 21 figures, 11 tables.

  4. Determinants for grading Malaysian rice

    NASA Astrophysics Data System (ADS)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  5. New determination equation for visibility

    SciTech Connect

    Fang Qiwan; Rao Jionghui; Ying Zhixiang; Tang Haijun; Jiang Chuanfu

    1996-12-31

    Range is an important tactical hard index in designing and manufacturing military laser rangefinders. But in practice it is also a soft index which is influenced by target characteristic and atmospheric visibility. In this article the problems in the range index are analyzed. The way to determine visibility is put forward. Extinction determination equation for visibility is derived. And it is applied in practice, which verifies the determination equation is functional and effective.

  6. Confirming criticality safety of TRU waste with neutron measurements and risk analyses

    SciTech Connect

    Winn, W.G.; Hochel, R.D.

    1992-04-01

    The criticality safety of {sup 239}Pu in 55-gallon drums stored in TRU waste containers (culverts) is confirmed using NDA neutron measurements and risk analyses. The neutron measurements yield a {sup 239}Pu mass and k{sub eff} for a culvert, which contains up to 14 drums. Conservative probabilistic risk analyses were developed for both drums and culverts. Overall {sup 239}Pu mass estimates are less than a calculated safety limit of 2800 g per culvert. The largest measured k{sub eff} is 0.904. The largest probability for a critical drum is 6.9 {times} 10{sup {minus}8} and that for a culvert is 1.72 {times} 10{sup {minus}7}. All examined suspect culverts, totaling 118 in number, are appraised as safe based on these observations.

  7. Confirming criticality safety of TRU waste with neutron measurements and risk analyses

    SciTech Connect

    Winn, W.G.; Hochel, R.D.

    1992-01-01

    The criticality safety of {sup 239}Pu in 55-gallon drums stored in TRU waste containers (culverts) is confirmed using NDA neutron measurements and risk analyses. The neutron measurements yield a {sup 239}Pu mass and k{sub eff} for a culvert, which contains up to 14 drums. Conservative probabilistic risk analyses were developed for both drums and culverts. Overall {sup 239}Pu mass estimates are less than a calculated safety limit of 2800 g per culvert. The largest measured k{sub eff} is 0.904. The largest probability for a critical drum is 6.9 {times} 10{sup {minus}8} and that for a culvert is 1.72 {times} 10{sup {minus}7}. All examined suspect culverts, totaling 118 in number, are appraised as safe based on these observations.

  8. The effect of isotope on the dosimetry of inhaled plutonium oxide

    SciTech Connect

    Guilmette, R.A., Griffith, W.C.; Hickman, A.W.

    1991-12-31

    Results of experimental studies in which animals inhaled {sup 238}PuO{sub 2} or {sup 239}PuO{sub 2} aerosols have shown that the biokinetics and associated radiation dose patterns for these two isotopes differ significantly due to differences in in-vivo solubility caused by the 260-fold difference in specific activity between {sup 238}PuO{sub 2} and {sup 239}PuO{sub 2}. We have adapted a biokinetics and dosimetry model derived from results of the ITRI dog studies to humans and have calculated dose commitments and annual limits on intake (ALI) for both Pu isotopes. Our results show that the ALI calculated in this study is one-third that for class Y {sup 238}Pu from ICRP 30, and one-half or equal to that for class Y {sup 239}Pu, depending on how activity in the thoracic lymph nodes is treated dosimetrically.

  9. Feasibility study of plutonium isotopic analysis of resin beads by nondestructive gamma-ray spectroscopy

    SciTech Connect

    Li, T.K.

    1985-01-01

    We have initiated a feasibility study on the use of nondestructive low-energy gamma-ray spectroscopy for plutonium isotopic analysis on resin beads. Seven resin bead samples were measured, with each sample containing an average of 9 ..mu..g of plutonium; the isotopic compositions of the samples varied over a wide range. The gamma-ray spectroscopy results, obtained from 4-h counting-time measurements, were compared with mass spectrometry results. The average ratios of gamma-ray spectroscopy to mass spectrometry were 1.014 +- 0.025 for /sup 238/Pu//sup 239/Pu, 0.996 +- 0.018 for /sup 240/Pu//sup 239/Pu, and 0.980 +- 0.038 for /sup 241/Pu//sup 239/Pu. The rapid, automated, and accurate nondestructive isotopic analysis of resin beads may be very useful to process technicians and International Atomic Energy Agency inspectors. 3 refs., 1 fig., 3 tabs.

  10. Automated monitoring of in-process plutonium concentration

    SciTech Connect

    Rebagay, T.V.; Huff, G.A.; Hofstetter, K.J.

    1982-01-01

    An automated low-level plutonium monitor capable of measuring total and isotopic plutonium abundances in solutions is described. To demonstrate near real-time assay of in-process plutonium, we installed a monitor on a flowing stream of a laboratory experimental facility. The stream was composed of uranium and plutonium in nitric acid at concentrations typical of a plant using a Purex flowsheet modified to permit coprocessing of spent nuclear fuel. The plutonium isotopic abundances were typical of those found in light water reactor grade fuel. The plutonium isotopic concentrations in the stream with the exception of /sup 242/Pu were determined by direct lambda-ray spectrometry. The /sup 242/Pu abundance was calculated by isotope correlation techniques. Additional data were obtained on coprocessed uranium-plutonium solutions denatured with fission products (/sup 103/Ru, /sup 144/Ce//sup 144/Pr, and /sup 95/Zr//sup 95/Nb). /sup 239/Pu and /sup 240/Pu concentrations can be determined to within 2% and 5%, respectively, of the concentrations determined by mass spectrometry.

  11. Distributions of cell populations within. cap alpha. -particle range of plutonium deposits in the rat and beagle testis

    SciTech Connect

    Miller, S.C.; Rowland, H.G.; Bowman, B.M.

    1985-01-01

    Plutonium is not uniformly distributed in testicular tissues; thus some cell populations may receive larger or smaller radiation exposures than would be expected if the nuclide were uniformly distributed. The distributions of cell populations within ..cap alpha..-particle range of Pu deposits in rat and beagle testes were determined. The data were collected from autoradiographs of testicular tissues containing /sup 241/Pu. A cell distribution factor (CDF) was determined for each cell population and is defined as the average number of each cell type within ..cap alpha..-particle range of each observed Pu deposit relative to the number of each cell type that would be expected within ..cap alpha..-particle range of each Pu deposit, if the deposits were distributed uniformly. In addition, the percentage of the spermatogonial stem cell population within ..cap alpha..-particle range of Pu deposits was determined. The largest CDFs seen in both species were in the interstitial tissues, particulary for Leydig cells. Because the organization of testicular tissues in the beagle is quite different from rodents but more similar to human, the results from this study suggest that extrapolations from rodents to humans may tend to overestimate the potential for radiation exposure to spermatogonial stem cells as well as the fraction of the spermatogonial stem cell population at risk to exposure from internally deposited /sup 239/Pu.

  12. In-plant measurements of gamma-ray transmissions for precise K-edge and passive assay of plutonium concentration and isotopic fractions in product solutions. Final report on TASTEX Task G

    SciTech Connect

    Russo, P.A.; Hsue, S.T.; Sprinkle, J.K. Jr.; Johnson, S.S.; Asakura, Y.; Kondo, I.; Masui, J.; Shoji, K.

    1982-08-01

    An instrument based upon high-resolution gamma-ray measurements has been tested for more than 1 year at the Tokai Reprocessing Facility for determination of plutonium concentration by K-edge absorption densitometry and for determination of plutonium isotopic fractions by transmission-corrected passive gamma-ray spectrometry. The nondestructive assay instrument was designed and built at Los Alamos National Laboratory for the Tokai Advanced Safeguards Technology Exercise (TASTEX). It was used at Tokai for the timely assay of more than 100 product solution samples during the TASTEX evaluations. The results were compared to reference values obtained by conventional destructive analysis of these samples. The precision and accuracy of plutonium concentrations measured by the K-edge technique are shown to be within 0.6% (1delta) in these applications. The precisions and accuracies of the isotopic fractions determined by these passive gamma-ray methods are shown to be within 0.4% for /sup 239/Pu, 1% for /sup 240/Pu and /sup 241/Pu, and 10% for /sup 242/Pu.

  13. Self-Determination. Feature Issue.

    ERIC Educational Resources Information Center

    IMPACT, 1994

    1994-01-01

    This theme issue explores the relevance of self-determination for persons with developmental disabilities across the life span, ways in which it is or can be expressed, and obstacles to its exercise. The articles show the futility of enhancing self-determination by teaching choice-making skills if environments offer no opportunities to exercise…

  14. The Resurgence of Biological Determinism.

    ERIC Educational Resources Information Center

    Segal, Elizabeth A.; Kilty, Keith M.

    1998-01-01

    Addresses two areas where science has been and still is used to justify policies and attitudes that are discriminatory and oppressive: homosexuality and alcoholism. This article analyzes the debate over whether these correlations are biologically or socially determined. Of particular concern is the potential impact of biological determinism on the…

  15. Precise Orbit Determination for ALOS

    NASA Technical Reports Server (NTRS)

    Nakamura, Ryo; Nakamura, Shinichi; Kudo, Nobuo; Katagiri, Seiji

    2007-01-01

    The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. Because the mounted sensors need high geometrical accuracy, precise orbit determination for ALOS is essential for satisfying the mission objectives. So ALOS mounts a GPS receiver and a Laser Reflector (LR) for Satellite Laser Ranging (SLR). This paper deals with the precise orbit determination experiments for ALOS using Global and High Accuracy Trajectory determination System (GUTS) and the evaluation of the orbit determination accuracy by SLR data. The results show that, even though the GPS receiver loses lock of GPS signals more frequently than expected, GPS-based orbit is consistent with SLR-based orbit. And considering the 1 sigma error, orbit determination accuracy of a few decimeters (peak-to-peak) was achieved.

  16. Sex determination: the amphibian models.

    PubMed

    Eggert, Christophe

    2004-01-01

    We review and discuss current knowledge about sex determination in amphibians. The astonishing wide variety of mechanisms of genotypic sex determination is presented and discussed in an evolutionary context. We recall the natural occurrence of transitory juvenile hermaphroditism in some species. Our present knowledge of the mechanisms of sex determination in amphibians is compared to that in mammals. The influence of epigenetic factors, and especially temperature is highlighted. In amphibians, the influence of temperature on sexual differentiation, that can prevail over genotypic sex determination, remains poorly considered in publications. We suggest that studies on genetic and epigenetic factors of gonadal sex differentiation in amphibians could provide substantial information on the evolutionary process of sex determination mechanisms in current living vertebrates. PMID:15762298

  17. Method of determining glass durability

    DOEpatents

    Jantzen, C.M.; Pickett, J.B.; Brown, K.G.; Edwards, T.B.

    1998-12-08

    A process is described for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, {Delta}G{sub p}, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, {Delta}G{sub a}, based upon the free energy associated with weak acid dissociation, {Delta}G{sub a}{sup WA}, and accelerated matrix dissolution at high pH, {Delta}G{sub a}{sup SB} associated with solution strong base formation, and determining a final hydration free energy, {Delta}G{sub f}. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log{sub 10}(N C{sub i}(g/L))=a{sub i} + b{sub i}{Delta}G{sub f}. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained. 4 figs.

  18. Method of determining glass durability

    DOEpatents

    Jantzen, Carol Maryanne; Pickett, John Butler; Brown, Kevin George; Edwards, Thomas Barry

    1998-01-01

    A process for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, .DELTA.G.sub.p, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, .DELTA.G.sub.a, based upon the free energy associated with weak acid dissociation, .DELTA.G.sub.a.sup.WA, and accelerated matrix dissolution at high pH, .DELTA.G.sub.a.sup.SB associated with solution strong base formation, and determining a final hydration free energy, .DELTA.G.sub.f. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log.sub.10 (N C.sub.i (g/L))=a.sub.i +b.sub.i .DELTA.G.sub.f. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained.

  19. Evans function and Fredholm determinants

    PubMed Central

    Karambal, Issa; Malham, Simon J. A.

    2015-01-01

    We explore the relationship between the Evans function, transmission coefficient and Fredholm determinant for systems of first-order linear differential operators on the real line. The applications we have in mind include linear stability problems associated with travelling wave solutions to nonlinear partial differential equations, for example reaction–diffusion or solitary wave equations. The Evans function and transmission coefficient, which are both finite determinants, are natural tools for both analytic and numerical determination of eigenvalues of such linear operators. However, inverting the eigenvalue problem by the free-state operator generates a natural linear integral eigenvalue problem whose solvability is determined through the corresponding infinite Fredholm determinant. The relationship between all three determinants has received a lot of recent attention. We focus on the case when the underlying Fredholm operator is a trace class perturbation of the identity. Our new results include (i) clarification of the sense in which the Evans function and transmission coefficient are equivalent and (ii) proof of the equivalence of the transmission coefficient and Fredholm determinant, in particular in the case of distinct far fields. PMID:25663806

  20. Erroneous theories of sex determination.

    PubMed Central

    Mittwoch, U

    1985-01-01

    Throughout the major part of history, theories of sex determination had to be formulated in the absence of knowledge of ova and spermatozoa. The most persistent theory postulated that males are associated with the right parental side and females with the left side. At the end of the 19th century, sex was thought to be determined by nutrition. Recent findings regarding bilateral asymmetry in human hermaphrodites and of temperature dependent sex determination in reptiles may restore a small degree of credibility to certain theories predating the discovery of sex chromosomes. Images PMID:3892005

  1. Mars Science Laboratory Orbit Determination

    NASA Technical Reports Server (NTRS)

    Kruizinga, Gerhard L.; Gustafson, Eric D.; Thompson, Paul F.; Jefferson, David C.; Martin-Mur, Tomas J.; Mottinger, Neil A.; Pelletier, Frederic J.; Ryne, Mark S.

    2012-01-01

    This paper describes the orbit determination process, results and filter strategies used by the Mars Science Laboratory Navigation Team during cruise from Earth to Mars. The new atmospheric entry guidance system resulted in an orbit determination paradigm shift during final approach when compared to previous Mars lander missions. The evolving orbit determination filter strategies during cruise are presented. Furthermore, results of calibration activities of dynamical models are presented. The atmospheric entry interface trajectory knowledge was significantly better than the original requirements, which enabled the very precise landing in Gale Crater.

  2. Chemical resolution of Pu+ from U+ and Am+ using a band-pass reaction cell inductively coupled plasma mass spectrometer.

    PubMed

    Tanner, Scott D; Li, Chunsheng; Vais, Vladimir; Baranov, Vladimir I; Bandura, Dmitry R

    2004-06-01

    Determination of the concentration and distribution of the Pu and Am isotopes is hindered by the isobaric overlaps between the elements themselves and U, generally requiring time-consuming chemical separation of the elements. A method is described in which chemical resolution of the elemental ions is obtained through ion-molecule reactions in a reaction cell of an ICPMS instrument. The reactions of "natural" U(+), (242)Pu(+), and (243)Am(+) with ethylene, carbon dioxide, and nitric oxide are reported. Since the net sensitivities to the isotopes of an element are similar, chemical resolution is inferred when one isobaric element reacts rapidly with a given gas and the isobar (or in this instance surrogate isotope) is unreactive or slowly reactive. Chemical resolution of the m/z 238 isotopes of U and Pu can be obtained using ethylene as a reaction gas, but little improvement in the resolution of the m/z 239 isobars is obtained. However, high efficiency of reaction of U(+) and UH(+) with CO(2), and nonreaction of Pu(+), allows the sub-ppt determination of (239)Pu, (240)Pu, and (242)Pu (single ppt for (238)Pu) in the presence of 7 orders of magnitude excess U matrix without prior chemical separation. Similarly, oxidation of Pu(+) by NO, and nonreaction of Am(+), permit chemical resolution of the isobars of Pu and Am over 2-3 orders of magnitude relative concentration. The method provides the potential for analysis of the actinides with reduced sample matrix separation. PMID:15167781

  3. An evaluation of meteorologic data differences between the Pantex Plant and Amarillo, Texas

    SciTech Connect

    Snyder, S.F.

    1993-06-01

    Meteorologic data from the Pantex Plant and from the nearby National Weather Service (NWS) station at the Amarillo, Texas, International Airport were evaluated to determine if the NWS data adequately represented meteorologic conditions at the Pantex Plant. Annual site environmental dose calculations for the Pantex Plant have previously used the NWS data; information from this data comparison helped determine if future environmental dose calculations should use site-specific Pantex meteorologic data. The meteorologic data evaluated were wind speed, wind direction, and atmospheric stability class. Atmospheric stability class data were compared for years 1990 and 1991 and found to be very similar. Stability class designations were identical and one class different in 63% and 30%, respectively, of the paired hourly data. An unexpected finding was the preponderance of Class D stability, which occurred approximately 62% of the time in both data sets. The overall effect of meteorological differences between the two locations was evaluated by performing environmental dose assessments using the GENII dose assessment computer code. Acute and chronic releases of {sup 3}H and {sup 239}Pu were evaluated. Results using the NWS Amarillo meteorologic data were approximately one-half of those generated using Pantex meteorologic data. The two-fold difference in dose results is within the uncertainty expected from current dose assessment codes; therefore, the two meteorologic databases can be used interchangeably and prior dose calculation results using the NWS Amarillo data are acceptable.

  4. Development of a Phosphate Ceramic as a Host for Halide-contaminated Plutonium Pyrochemical Reprocessing Wastes

    SciTech Connect

    Metcalfe, Brian; Fong, Shirley K.; Gerrard, Lee A.; Donald, Ian W.; Strachan, Denis M.; Scheele, Randall D.

    2007-03-31

    The presence of halide anions in four types of wastes arising from the pyrochemical reprocessing of plutonium required an immobilization process to be developed in which not only the actinide cations but also the halide anions were immobilized in a durable waste form. At AWE, we have developed such a process using Ca3(PO4)2 as the host material. Successful trials of the process with actinide- and Cl-bearing Type I waste were carried out at PNNL where the immobilization of the waste in a form resistant to aqueous leaching was confirmed. Normalized mass losses determined at 40°C and 28 days were 12 x 10-6 g∙m-2 and 2.7 x 10-3 g∙m-2 for Pu and Cl, respectively. Accelerated radiation-induced damage effects are being determined with specimens containing 238Pu. No changes in the crystalline lattice have been detected with XRD after the 239Pu equivalent of 400 years ageing. Confirmation of the process for Type II waste (a oxyhydroxide-based waste) is currently underway at PNNL. Differences in the ionic state of Pu in the four types of waste have required different surrogates to be used. Samarium chloride was used successfully as a surrogate for both Pu(III) and Am(III) chlorides. Initial investigations into the use of HfO2 as the surrogate for Pu(IV) oxide in Type II waste indicated no significant differences.

  5. Prompt Fission Neutron Energy Spectra Induced by Fast Neutrons

    NASA Astrophysics Data System (ADS)

    Staples, Parrish Alan

    Prompt fission neutron energy spectra for ^{235}U and ^{239 }Pu have been measured for fission neutron energies greater than the energy of the incident neutrons inducing fission. The measurements were undertaken to investigate the shape dependence of the fission neutron spectra upon both the incident neutron energy and the mass of the nucleus undergoing fission. Measurements were made for both nuclides at the following incident neutron energies; 0.50 MeV, 1.50 MeV, 2.50 MeV and 3.50 MeV. The data are presented either as relative yields or as ratios of a measured spectrum to the ^{235}U spectrum at 0.50 MeV. Incident neutrons were produced by the ^7Li(p,n)^7Be reaction using a pulsed, bunched proton beam from the 5.5 MV Van de Graaff accelerator at the University of Massachusetts Lowell Pinanski Energy Center. The neutrons were detected by a thin liquid scintillator with good time resolution capabilities; time-of-flight techniques were used for neutron energy determination; in addition pulse-shape-discrimination was used to reduce gamma-ray background levels. The measurements are compared to calculations based on the Los Alamos Model of Madland and Nix to test its predictive capabilities. The data are fit by the Watt equation to determine the mean energy of the spectra, and to facilitate comparison of the results to previous measurements. The data are also compared directly to previous measurements.

  6. Optimized Chemical Separation and Measurement by TE TIMS Using Carburized Filaments for Uranium Isotope Ratio Measurements Applied to Plutonium Chronometry.

    PubMed

    Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Prohaska, Thomas

    2016-06-21

    An optimized method is described for U/Pu separation and subsequent measurement of the amount contents of uranium isotopes by total evaporation (TE) TIMS with a double filament setup combined with filament carburization for age determination of plutonium samples. The use of carburized filaments improved the signal behavior for total evaporation TIMS measurements of uranium. Elevated uranium ion formation by passive heating during rhenium signal optimization at the start of the total evaporation measurement procedure was found to be a result from byproducts of the separation procedure deposited on the filament. This was avoided using carburized filaments. Hence, loss of sample before the actual TE data acquisition was prevented, and automated measurement sequences could be accomplished. Furthermore, separation of residual plutonium in the separated uranium fraction was achieved directly on the filament by use of the carburized filaments. Although the analytical approach was originally tailored to achieve reliable results only for the (238)Pu/(234)U, (239)Pu/(235)U, and (240)Pu/(236)U chronometers, the optimization of the procedure additionally allowed the use of the (242)Pu/(238)U isotope amount ratio as a highly sensitive indicator for residual uranium present in the sample, which is not of radiogenic origin. The sample preparation method described in this article has been successfully applied for the age determination of CRM NBS 947 and other sulfate and oxide plutonium samples. PMID:27240571

  7. The Influence of Hydrothermal Plumes on the Distribution of Anthropogenic Radionuclides Between the Particulate and Dissolved Phases: Results from U.S. Geotraces Equatorial Pacific Zonal Transect GP16

    NASA Astrophysics Data System (ADS)

    Kenna, T. C.; Villa Alfageme, M.; Casacuberta Arola, N.; Masque, P.

    2014-12-01

    Here we present and discuss the results from the analysis of samples from selected stations collected on the US GEOTRACES Equatorial Pacific Zonal Transect (GP16) completed in 2013. The section, between Peru and Tahiti, encompasses a range of processes that influence the supply, removal, and internal cycling of trace metals and offers the opportunity to gain a better understanding of the drivers of the transport and fate of contaminants in the ocean. The capability to analyze water and filtered particulate samples in the quantities available, allows us to determine the partitioning of selected radionuclides among dissolved and particulate forms (Kd) and estimate Pu-particulate fluxes. The overarching objective of our work is to determine the concentrations of several anthropogenic radionuclides, including 239Pu, 240Pu, 237Np, and 137Cs with sufficient resolution to define their basin-wide distributions in the Pacific Ocean. Data collected in the East Pacific Rise hydrothermal plume allows a discussion on the partitioning behavior of plutonium and neptunium.

  8. Water treatment cartridge filter pilot test at Pond C-2

    SciTech Connect

    Moritz, E.J.; Hoffman, C.R.

    1994-12-31

    This study determined the performance of a pilot scale cartridge filter tank utilized to treat raw water at Rocky Flats Plant terminal Pond C-2. No chemical treatment was used during this study. The filter tank was fitted with eight polypropylene 3M{reg_sign} Model 723 cartridges vendor rated at 99% removal efficiency for particles of 2 microns and larger. The duration of the test was 30 minutes at a flowrate of 200 gallons per minutes. Performance was determined by measuring total suspended solids (TSS), total dissolved solids (TDS), nephelometric turbidity units (NTU), gross alpha activity, gross beta activity, plutonium ({sup 239}Pu) levels, total particle counts (TPC), and differential particle counts (DPC) before and after treatment at specific time intervals throughout the test. Performance testing shows this treatment method produced a high quality effluent. Compared to raw water levels, TSS, NTU, gross alpha, and Pu{sup 239} were significantly reduced in the treated water samples. TPC and DPC data showed an average filtration efficiency of 97% for particles in the 1--50 micron range. This treatment method had no statistically significant affect on TDS and gross beta activity levels.

  9. Rapid isolation of plutonium in environmental solid samples using sequential injection anion exchange chromatography followed by detection with inductively coupled plasma mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-31

    This paper reports an automated analytical method for rapid determination of plutonium isotopes ((239)Pu and (240)Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from matrix and interfering elements. The analytical results most distinctly demonstrated that the crosslinkage of the anion exchanger is a key parameter controlling the separation efficiency. AG 1-×4 type resin was selected as the most suitable sorbent material for analyte separation. Investigation of column size effect upon the separation efficiency revealed that small-sized (2 mL) columns sufficed to handle up to 50 g of environmental soil samples. Under the optimum conditions, chemical yields of plutonium exceeded 90% and the decontamination factors for uranium, thorium and lead ranged from 10(3) to 10(4). The determination of plutonium isotopes in three standard/certified reference materials (IAEA-375 soil, IAEA-135 sediment and NIST-4359 seaweed) and two reference samples (Irish Sea sediment and Danish soil) revealed a good agreement with reference/certified values. The SI column-separation method is straightforward and less labor intensive as compared with batch-wise anion exchange chromatographic procedures. Besides, the automated method features low consumption of ion-exchanger and reagents for column washing and elution, with the consequent decrease in the generation of acidic waste, thus bearing green chemical credentials. PMID:21168558

  10. A preliminary evaluation of certain NDA techniques for RH-TRU characterization

    SciTech Connect

    Hartwell, J.K.; Yoon, W.Y.; Peterson, H.K.

    1996-12-31

    This report presents the results of modeling efforts to evaluate selected NDA assay methods for RH-TRU waste characterization. The target waste stream was Content Code 104/107 113-liter waste drums that comprise the majority of the INEL`s RH-TRU waste inventory. Two NDA techniques are treated in detail. One primary NDA technique examined is gamma-ray spectrometry to determine the drum fission and activation product content, and fuel sample inventory calculations using the ORIGEN code to predict the total drum inventory. A heavily shielded and strongly collimated HPGE spectrometer system was designed using MCNP modeling. Detection limits and expected precision of this approach were estimated by a combination of Monte Carlo modeling and synthetic gamma-ray spectrum generation. This technique may allow the radionuclide content of these wastes to be determined with relative standard deviations of 20 to 55% depending on the drum matrix and radionuclide. The INEL Passive/Active Neutron (PAN) assay system is the second primary technique considered. A shielded overpack for the 113-liter CC104/107 RH-TRU drums was designed to shield the PAN detectors from excessive gamma radiation. MCNP modeling suggests PAN detection limits of about 0.06 g {sup 235}U and 0.04 g {sup 239}Pu during active assays.

  11. A gamma-ray verification system for special nuclear material

    SciTech Connect

    Lanier, R.G.; Prindle, A.L.; Friensehner, A.V.; Buckley, W.M.

    1994-07-01

    The Safeguards Technology Program at the Lawrence Livermore National Laboratory (LLNL) has developed a gamma-ray screening system for use by the Materials Management Section of the Engineering Sciences Division at LLNL for verifying the presence or absence of special nuclear material (SNM) in a sample. This system facilitates the measurements required under the ``5610`` series of US Department of Energy orders. MMGAM is an intelligent, menu driven software application that runs on a personal computer and requires a precalibrated multi-channel analyzer and HPGe detector. It provides a very quick and easy-to-use means of determining the presence of SNM in a sample. After guiding the operator through a menu driven set-up procedure, the system provides an on-screen GO/NO-GO indication after determining the system calibration status. This system represents advances over earlier used systems in the areas of ease-of use, operator training requirements, and quality assurance. The system records the gamma radiation from a sample using a sequence of measurements involving a background measurement followed immediately by a measurement of the unknown sample. Both spectra are stored and available for analysis or output. In the current application, the presence of {sup 235}U, {sup 238}U, {sup 239}Pu, and {sup 208}Tl isotopes are indicated by extracting, from the stored spectra, four energy ``windows`` preset around gamma-ray lines characteristic of the radioactive decay of these nuclides. The system is easily extendible to more complicated problems.

  12. A preliminary evaluation of certain NDA techniques for RH-TRU characterization

    SciTech Connect

    Hartwell, J.K.; Yoon, W.Y.; Peterson, H.K.

    1997-11-01

    This report presents the results of modeling efforts to evaluate selected NDA assay methods for RH-TRU waste characterization. The target waste stream was Content Code 104/107 113-liter waste drums that comprise the majority of the INEL`s RH-TRU waste inventory. Two NDA techniques are treated in detail. One primary NDA technique examined is gamma-ray spectrometry to determine the drum fission and activation product content, and fuel sample inventory calculations using the ORIGEN code to predict the total drum inventory. A heavily shielded and strongly collimated HPGe spectrometer system was designed using MCNP modeling. Detection limits and expected precision of this approach were estimated by a combination of Monte Carlo modeling and synthetic gamma-ray spectrum generation. This technique may allow the radionuclide content of these wastes to be determined with relative standard deviations of 20 to 50% depending on the drum matrix and radionuclide. The INEL Passive/Active Neutron (PAN) assay system is the second primary technique considered. A shielded overpack for the 113-liter CC104/107 RH-TRU drums was designed to shield the PAN detectors from excessive gamma radiation. MCNP modeling suggests PAN detection limits of about 0.06 g {sup 235}U and 0.04 g {sup 239}Pu during active assays. 12 refs., 2 figs., 6 tabs.

  13. Characterization of natural water resources in Israel by inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Halicz, L.; Becker, J. S.; Pickhardt, C.; Gavrieli, I.; Burg, A.; Nishri, A.; Platzner, I. T.

    2006-03-01

    Analytical procedures are applied for the determination of plutonium, uranium and strontium concentration, their isotope ratios and the analysis of rare earth elements (REE) at trace and ultratrace level in natural Israeli water resources with relatively high matrix content (Na = 20-150 mg L-1, Mg = 20-50 mg L-1 and Ca = 40-100 mg L-1) by inductively coupled plasma mass spectrometry (ICP-MS). To avoid matrix and clogging effects on the cones during mass spectrometric measurements and to analyze Pu and REE at extremely low concentration levels, separation procedures from matrices were applied. An extremely low Pu contamination of the Sea of Galilee was observed due to global nuclear fallout after the nuclear weapons test in the 1960s. The detection limit, for example, for 239Pu was found to be <10-19 g mL-1. For uranium a natural variation of the 234U/238U isotope ratios by a factor of up to 2 in comparison to the IUPAC table value was detected using ICP-MS. This paper discusses the application of double-focusing sector field ICP-MS with single and multiple ion collection as well as quadrupole-based ICP-MS (ICP-QMS) for the quantitative determination of REE, plutonium, uranium and strontium and their isotope ratios after analyte/matrix separation at trace and ultratrace levels in natural water.

  14. Cesium, americium and plutonium isotopes in ground level air of vilnius

    NASA Astrophysics Data System (ADS)

    Lujaniene, G.; Šapolaite, J.; Remeikis, V.; Lujanas, V.; Jermolajev, A.; Aninkevičius, V.

    2006-01-01

    Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of 137Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of 238Pu, 239,240Pu, 241Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995 2003 of 241Am and 239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m3, respectively. 238Pu/239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in 240Pu/239Pu atomic ratio from 0.30 to 0.19 was observed in 1995 2003.

  15. Teacher Compensation and Its Determinants

    ERIC Educational Resources Information Center

    Reiter, Herbert D.

    1974-01-01

    Examines the relationship among environmental influences, per pupil expenditures, and teacher salaries and debates the question whether collective negotiation or environmental influences are the prime determinant of teacher salaries. (Author/DN)

  16. Step 4: NCI Funding Determinations

    Cancer.gov

    Funding determinations are made around Oct. 1 each federal fiscal year. These decisions take into account several factors, including Congressional mandates, new scientific opportunities and program priorities when deciding which grants receive funding.

  17. Determination of plutonium metal origins

    SciTech Connect

    Moody, K.J.

    1995-02-01

    Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed and several parameters determined that are strong indicators of its point of origin.

  18. Gender determination of avian embryo

    DOEpatents

    Daum, Keith A.; Atkinson, David A.

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  19. Determination of zirconium in steels.

    PubMed

    Iyer, C S; Asari, T P

    1989-03-01

    The determination of zirconium in the range 0.01-0.20% is required for some special alloy steels. A method has been developed, based on initial removal of iron as its chloro-complex by extraction with methyl isobutyl ketone, followed by further extraction after addition of potassium thiocyanate, and determination of the zirconium left in the aqueous phase, with Arsenazo III. The absorbance is measured at 665 nm. PMID:18964725

  20. Radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin

    SciTech Connect

    Booher, J.L.; Fresquez, P.R.; Carter, L.F.; Gallaher, B.M.; Mullen, M.A.

    1998-02-01

    In 1992-93, Los Alamos National Laboratory collaborated with the U.S. Geological Survey in an effort to characterize radionuclide concentrations in bed sediment and fish tissue within the Rio Grande drainage basin from Colorado to Texas. Bed sediment was sampled from 18 locations for cesium ({sup 137}Cs), tritium ({sup 3}H), strontium ({sup 90}Sr), plutonium ({sup 238}Pu and {sup 239}Pu), americium ({sup 241}Am), total uranium ({sup tot}U) and alpha, beta, and gamma activity. Fish tissue was sampled from 12 locations for {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239}Pu and {sup tot}U.

  1. Incidence of plutonium-induced bone cancer in neutered mice

    SciTech Connect

    Taylor, G.N.; Gardner, P.; Mays, C.W.; Wrenn, M.E.; Charrier, K.

    1981-03-01

    The incidence of bone cancer, after a single i.p. injection of monomeric /sup 239/Pu citrate, is significantly higher in female than in male mice. To evaluate the role of the gonads in this sex-related difference, male and female C57BL/Do (albino) mice were castrated at 40 days of age. Fifty days later, they were given injections of /sup 239/Pu. After castration, the frequency of bone sarcomas in the two sexes was approximately equal. This resulted from an increased incidence in the castrated males and a decreased incidence in the ovariectomized females as compared to the intact plutonium-treated mice.

  2. Excitation of Energy Levels of Fissionable Nucleus Shape Isomers in the Doorway State in Reactions with Neutrons and Deuterons

    SciTech Connect

    Serov, V.I.; Andreev, M.F.; Zavgorodny, V.A.

    2005-05-24

    Measurements were conducted for the fission neutron yields with fission fragments in the (d,pf) reactions at some excitation energies, where threshold neutrons were discovered. These data on the neutron yields in 233U(d,pfn) and 239Pu(d,pfn) reactions have been compared with the dependence of the average of fission neutrons vp(En) in the 233U(n,f) reaction as well as fission probability in the 239Pu(d,pf) reaction on excitation energy, which provides a better understanding of the nuclear fission process in a (d,pf) reaction and the vp(En) dependence on neutron energy.

  3. Self-regulating neutron coincidence counter

    DOEpatents

    Baron, N.

    1980-06-16

    A device for accurately measuring the mass of /sup 240/Pu and /sup 239/Pu in a sample having arbitrary moderation and mixed with various contaminants. The device utilizes a thermal neutron well counter which has two concentric rings of neutron detectors separated by a moderating material surrounding the well. Neutron spectroscopic information derived by the two rings of detectors is used to measure the quantity of /sup 239/Pu and /sup 240/Pu in device which corrects for background radiation, deadtime losses of the detector and electronics and various other constants of the system.

  4. Subchronic inhalation of carbon tetrachloride alters the tissue retention of acutely inhaled plutonium-239 nitrate in F344 rats and syrian golden hamsters

    SciTech Connect

    Benson, J.M.; Barr, E.B.; Lundgren, D.L.

    1995-12-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is likely that nuclear plant workers have been exposed to both CCl{sub 4} and plutonium compounds. Future exposures may occur during {open_quotes}cleanup{close_quotes} operations at weapons productions sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. Inhalation of 20 and 100 ppm CCl{sub 4} by hamsters reduces uptake of {sup 239}Pu solubilized from lung, shunting the {sup 239}Pu to the skeleton.

  5. Applications of Photonuclear Physics for International Safeguards and Security

    SciTech Connect

    Johnson, M S; Hall, J M; McNabb, D P; McFarland, J; Norman, E; Bertozzi, W; Korbly, S; Ledoux, R; Park, W

    2010-04-16

    Studies of nuclear resonance fluorescence based applications are presented. Important for these applications are data for isotopes such as {sup 239}Pu. Nuclear resonance fluorescence measurements of {sup 239}Pu were performed at the free electron laser facility at UC Santa Barbara using photons from a bremsstrahlung beam with an endpoint energies between 4.0 MeV and 5.5 MeV. Though no discrete states with significant confidence level were measured, we have excluded the region above 27(3) eV-barns, or 4-sigma, where we would expect only a small chance of false positives. Details of the measurements and the results are presented here.

  6. Lunar Prospector Orbit Determination Results

    NASA Technical Reports Server (NTRS)

    Beckman, Mark; Concha, Marco

    1998-01-01

    The orbit support for Lunar Prospector (LP) consists of three main areas: (1) cislunar orbit determination, (2) rapid maneuver assessment using Doppler residuals, and (3) routine mapping orbit determination. The cislunar phase consisted of two trajectory correction maneuvers during the translunar cruise followed by three lunar orbit insertion burns. This paper will detail the cislunar orbit determination accuracy and the real-time assessment of the cislunar trajectory correction and lunar orbit insertion maneuvers. The non-spherical gravity model of the Moon is the primary influence on the mapping orbit determination accuracy. During the first two months of the mission, the GLGM-2 lunar potential model was used. After one month in the mapping orbit, a new potential model was developed that incorporated LP Doppler data. This paper will compare and contrast the mapping orbit determination accuracy using these two models. LP orbit support also includes a new enhancement - a web page to disseminate all definitive and predictive trajectory and mission planning information. The web site provides definitive mapping orbit ephemerides including moon latitude and longitude, and four week predictive products including: ephemeris, moon latitude/longitude, earth shadow, moon shadow, and ground station view periods. This paper will discuss the specifics of this web site.

  7. A Predictive Framework for Determining How Journalists Determine News.

    ERIC Educational Resources Information Center

    Gaudino, James L.

    To determine how to articulate a concrete definition of the substance of the journalist's occupation, this paper offers a propositional framework of news value based on Kurt Lewin's gatekeeper model. First, the paper follows the established suggestion that news decisions are best studied from a gatekeeping perspective or that "news is whatever…

  8. Ecotoxicological Perspectives of Sex Determination.

    PubMed

    Mizoguchi, Beatriz A; Valenzuela, Nicole

    2016-01-01

    Sex determination or the commitment of the embryo to its sexual fate is a fundamental developmental process with paramount consequences in ecology and evolution. This process, whether triggered by environmental factors or genotypic constitution, can be derailed by environmental contaminants that alter the endocrine system, which is a key component of the regulatory network underlying vertebrate sex determination. Here, we review the molecular basis of sex determination, the endocrine components of its regulation, the maternal and endogenous sources of hormones to the developing embryo, and the routes through which endocrine disrupting chemicals (EDCs) affect gonadal development in reptiles, especially turtles. Among EDCs, we focus on PCBs, BPA, pesticides like atrazine, nitrates, and heavy metals. We also consider whether adaptation might be possible in the face of persistent chemical insult and conclude that, while plausible, contemporary environmental change may outpace adaptive evolution, particularly for many species that are already endangered and suffer from small population sizes. PMID:27022970

  9. Spectral Determinants on Mandelstam Diagrams

    NASA Astrophysics Data System (ADS)

    Hillairet, Luc; Kalvin, Victor; Kokotov, Alexey

    2016-04-01

    We study the regularized determinant of the Laplacian as a functional on the space of Mandelstam diagrams (noncompact translation surfaces glued from finite and semi-infinite cylinders). A Mandelstam diagram can be considered as a compact Riemann surface equipped with a conformal flat singular metric {|ω|^2}, where {ω} is a meromorphic one-form with simple poles such that all its periods are pure imaginary and all its residues are real. The main result is an explicit formula for the determinant of the Laplacian in terms of the basic objects on the underlying Riemann surface (the prime form, theta-functions, the canonical meromorphic bidifferential) and the divisor of the meromorphic form {ω}. As an important intermediate result we prove a decomposition formula of the type of Burghelea-Friedlander-Kappeler for the determinant of the Laplacian for flat surfaces with cylindrical ends and conical singularities.

  10. Determining distances using asteroseismic methods

    NASA Astrophysics Data System (ADS)

    Silva Aguirre, V.; Casagrande, L.; Basu, S.; Campante, T. L.; Chaplin, W. J.; Huber, D.; Miglio, A.; Serenelli, A. M.

    2013-02-01

    Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the results is needed. In this talk, I present a new technique developed to obtain stellar properties by coupling asteroseismic analysis with the infrared flux method. Using two global seismic observables and multi-band photometry, the technique determines masses, radii, effective temperatures, bolometric fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the Kepler field that have accurate Hipparcos parallaxes, we find agreement in our distance determinations to better than 5 %. Comparison with measurements of spectroscopic effective temperatures and interferometric radii also validate our results, and show that our technique can be applied to stars evolved beyond the main-sequence phase.

  11. Determination of radium in water

    USGS Publications Warehouse

    Barker, Franklin Butt; Johnson, J.O.

    1964-01-01

    Radium isotopes are common radioactive constituents of natural waters. The concentration of radium-226 in potable water is of particular significance because this isotope is generally considered the most hazardous of all radionuclides with respect to ingestion. The approximate concentration of radium-226 is determined after coprecipitating radium with barium sulfate. The short-lived daughters of radium are allowed to grow for 10-12 days, then the alpha activity of the precipitate is measured and compared with that of a precipitate containing a known amount of radium-226. Concentrations of the individual alpha-emitting isotopes of radium-223, radium-224, and radium-226, are determined by coprecipitating radium first with lead sulfate, then with barium chloride, and finally with barium sulfate. This final precipitate is initially free of other alpha-emitting nuclides, thus permitting the isotopic composition to be determined by measuring the growth and decay of the alpha activity of the precipitate.

  12. Lessons for Inductive Germline Determination

    PubMed Central

    Seervai, Riyad N.H.; Wessel, Gary M.

    2015-01-01

    SUMMARY Formation of the germline in an embryo marks a fresh round of reproductive potential, yet the developmental stage and location within the embryo where the primordial germ cells (PGCs) form differs wildly among species. In most animals, the germline is formed either by an inherited mechanism, in which maternal provisions within the oocyte drive localized germ-cell fate once acquired in the embryo, or an inductive mechanism that involves signaling between cells that directs germ-cell fate. The inherited mechanism has been widely studied in model organisms such as Drosophila melanogaster, Caenorhabditis elegans, Xenopus laevis, and Danio rerio. Given the rapid generation time and the effective adaptation for laboratory research of these organisms, it is not coincidental that research on these organisms has led the field in elucidating mechanisms for germline specification. The inductive mechanism, however, is less well understood and is studied primarily in the mouse (Mus musculus). In this review, we compare and contrast these two fundamental mechanisms for germline determination, beginning with the key molecular determinants that play a role in the formation of germ cells across all animal taxa. We next explore the current understanding of the inductive mechanism of germ-cell determination in mice, and evaluate the hypotheses for selective pressures on these contrasting mechanisms. We then discuss the hypothesis that the transition between these determination mechanisms, which has happened many times in phylogeny, is more of a continuum than a binary change. Finally, we propose an analogy between germline determination and sex determination in vertebrates—two of the milestones of reproduction and development—in which animals use contrasting strategies to activate similar pathways. PMID:23450642

  13. Determinate-state convolutional codes

    NASA Technical Reports Server (NTRS)

    Collins, O.; Hizlan, M.

    1991-01-01

    A determinate state convolutional code is formed from a conventional convolutional code by pruning away some of the possible state transitions in the decoding trellis. The type of staged power transfer used in determinate state convolutional codes proves to be an extremely efficient way of enhancing the performance of a concatenated coding system. The decoder complexity is analyzed along with free distances of these new codes and extensive simulation results is provided of their performance at the low signal to noise ratios where a real communication system would operate. Concise, practical examples are provided.

  14. MEANS FOR DETERMINING CENTRIFUGE ALIGNMENT

    DOEpatents

    Smith, W.Q.

    1958-08-26

    An apparatus is presented for remotely determining the alignment of a centrifuge. The centrifage shaft is provided with a shoulder, upon which two followers ride, one for detecting radial movements, and one upon the shoulder face for determining the axial motion. The followers are attached to separate liquid filled bellows, and a tube connects each bellows to its respective indicating gage at a remote location. Vibrations produced by misalignment of the centrifuge shaft are transmitted to the bellows, and tbence through the tubing to the indicator gage. This apparatus is particularly useful for operation in a hot cell where the materials handled are dangerous to the operating personnel.

  15. Decoherence, determinism and chaos revisited

    SciTech Connect

    Noyes, H.P.

    1994-11-15

    We suggest that the derivation of the free space Maxwell Equations for classical electromagnetism, using a discrete ordered calculus developed by L.H. Kauffman and T. Etter, necessarily pushes the discussion of determinism in natural science down to the level of relativistic quantum mechanics and hence renders the mathematical phenomena studied in deterministic chaos research irrelevant to the question of whether the world investigated by physics is deterministic. We believe that this argument reinforces Suppes` contention that the issue of determinism versus indeterminism should be viewed as a Kantian antinomy incapable of investigation using currently available scientific tools.

  16. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1993-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  17. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1992-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  18. Radionuclide concentrations in soils and produce from Cochiti, Jemez, Taos, and San Ildefonso Pueblo Gardens

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Salazar, J.G.

    1995-05-01

    Radionuclide ({sup 3}H, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium) concentrations were determined in soils and produce collected from Cochiti, Jemez, Taos, and San Ildefonso Pueblo gardens. All radionuclides in soils from Pueblo areas were within or just above regional statistical (natural and/or worldwide fallout) reference levels. Similarily, the average levels of radionuclides in produce collected from Cochiti, Jemez, Taos, and San Ildefonso Pueblo gardens were not significantly different in produce collected from regional (background) locations. The effective (radiation) dose equivalent from consuming 352 lb of produce from Cochiti, Jemez, Taos, and San Ildefonso, after natural background has been subtracted, was 0.036 ({+-}0.016), 0.072 ({+-}0.051), 0.012 ({+-}0.027), and 0.110 ({+-}0.102) mrem/yr, respectively. The highest calculated dose, based on the mean + 2 std dev (95% confidence level), was 0.314 mrem/yr; this was <0.4% of the International Commission on Radiological Protection permissible dose limit for protecting members of the public.

  19. Measured solubilities and speciations from oversaturation experiments of neptunium, plutonium, and americium in UE-25p No. 1 well water from the Yucca Mountain region: Milestone report 3329-WBS1.2.3.4.1.3.1

    SciTech Connect

    Nitsche, H.; Roberts, K.; Prussin, T.; Mueller, A.; Becraft, K.; Keeney, D.; Carpenter, S.A.; Gatti, R.C.

    1994-04-01

    Solubility and speciation are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are a part of predictive transport models. Results are presented from solubility and speciation experiments of {sup 237}NpO{sub 2}{sup +}, {sup 239}Pu{sup 4+}, and {sup 241}Am{sup 3+}/Nd{sup 3+} in a modified UE-25p No. 1 groundwater (from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site) at two different temperatures (25{degree} and 60{degree}C) and three pH values (6.0, 7.0, 8.5). The solubility-controlling steady-state solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined. The neptunium solubility decreased with increasing temperature and pH. Plutonium concentrations significantly decreased with increasing temperature at pH 6 and 7. The concentration at pH 8.5 hardly decreased at all with increasing temperature. At both temperatures the concentrations were highest at pH 8.5, lowest at pH 7, and in between at pH 6. For the americium/neodymium solutions, the solubility decreased significantly with increasing temperature and increased somewhat with increasing pH.

  20. Radionuclide concentrations in elk that winter on Los Alamos National Laboratory lands

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.A.; Salazar, J.G.

    1994-07-01

    Elk spend the winter in areas at Los Alamos National Laboratory (LANL) that may contain radioactivity above natural and/or worldwide fallout levels. This study was initiated to determine the levels of {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium in various tissues (brain, hair, heart, jawbone, kidneys, leg bone, liver, and muscle) of adult cow elk that use LANL lands during the fall/winter months. No significant differences in radionuclide contents were detected in any of the tissue samples collected from elk on LANL lands as compared with elk collected from off-site locations. The total effective (radiation) dose equivalent a person would receive from consuming 3.2 lb of heart, 5.6 lb of liver, and 226 lb of muscle from elk that winter on LANL lands, after natural background has been subtracted, was 0.00008, 0.0001, and 0.008 mrem/yr, respectively. The highest dose was less than 0.01% of the International Commission of Radiological Protection permissible dose limit for protecting the public.

  1. EMP Attachment 1 DOE-SC PNNL Site Sampling and Analysis Plan

    SciTech Connect

    Meier, Kirsten M.

    2011-11-10

    This Sampling and Analysis Plan (SAP) is written for the radiological environmental air surveillance program for the DOE-SC PNNL Site, Richland Washington. It provides the requirements for planning sampling events, and the requirements imposed on the analytical laboratory analyzing the air samples. The actual air sampling process is in procedure EPRP-AIR-029. The rationale for analyte selection, media, and sampling site location has been vetted through the data quality objectives (DQO) process (Barnett et al. 2010). The results from the DQO process have been reviewed and approved by the Washington State Department of Health. The DQO process (Barnett et al. 2010) identified seven specific radionuclides for analysis along with the need for gross alpha and gross beta radiological analyses. The analytes are {sup 241}Am, {sup 243}Am, {sup 244}Cm, {sup 60}Co, {sup 238}Pu, {sup 239}Pu, and {sup 233}U. The report also determined that air samples for particulates are the only sample matrix required for the monitoring program. These samples are collected on 47-mm glass-fiber filters.

  2. Prompt Fission Neutron Experiments on 235U(n,f) and 252Cf(SF)

    NASA Astrophysics Data System (ADS)

    Göök, A.; Hambsch, F.-J.; Oberstedt, S.; Vidali, M.

    For nuclear modeling and improved evaluation of nuclear data knowledge about fluctuations of the prompt neutron multiplicity as a function of incident neutron energy is requested for the major actinides 235U and 239Pu. Experimental investigations of the prompt fission neutron emission in resonance neutron induced fission on 235U are taking place at the GELINA facility of the IRMM. The experiment employs an array of neutron scintillation-detectors (SCINTIA) in conjunction with a newly designed 3D position sensitive twin Frisch-grid ionization chamber. A preparatory experiment on prompt fission neutron emission in 252Cf(SF) was undertaken to verify analysis procedures relevant for the implementation of the SCINTIA neutron detector array. The available literature data on the TKE dependence of the multiplicity show strong deviations. Therefore, effort was focused on investigating experimental factors in low efficiency neutron counting experiments that may lead to faulty determination of this dependence. Taking these factors into account a result that agree well with data from high efficiency neutron counting experiments is obtained.

  3. Rapid alpha spectroscopy of evaporated liquid residues for emergency response.

    PubMed

    Semkow, T M; Khan, A J; Haines, D K; Bari, A

    2009-04-01

    A new method for alpha spectroscopy of evaporated water residues was developed, consisting of evaporation of drinking water, flaming of the planchets, and alpha-spectroscopic measurements using a grid ionization chamber. The method can identify and quantify radioactivity concentrations > or =3 mBq L-1 in a matter of several hours, whereas determination of sub-mBq L-1 levels is achievable in 1 day. Detailed investigations of flaming of the planchets, the humidity effect, and alpha spectroscopy of thick sources are described. A three-dimensional calibration of the method was performed using standards containing 238U, 230Th, 239Pu, 241Am, and 244Cm radionuclides. In addition to its application to evaporated drinking water, this calibration is common for any environmental sample that can be prepared as a uniform layer, such as the residues from surface water, acidic washing or leaching from materials, as well as biological fluids such as urine. The developed method serves as a fast identifying or screening technique for emergency response involving alpha radioactivity. PMID:19276703

  4. EURADOS intercomparison on emergency radiobioassay.

    PubMed

    Li, Chunsheng; Battisti, Paolo; Berard, Philippe; Cazoulat, Alain; Cuellar, Antonio; Cruz-Suarez, Rodolfo; Dai, Xiongxin; Giardina, Isabella; Hammond, Derek; Hernandez, Carolina; Kiser, Stephen; Ko, Raymond; Kramer-Tremblay, Sheila; Lecompte, Yannick; Navarro, Eva; Navas, Cristina; Sadi, Baki; Sierra, Inmaculada; Verrezen, Freddy; Lopez, Maria A

    2015-12-01

    Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories. PMID:25543132

  5. Comparison of U.S. Environmental Protection Agency's CAP88 PC Versions 3.0 and 4.0.

    PubMed

    Jannik, Tim; Farfan, Eduardo B; Dixon, Ken; Newton, Joseph; Sailors, Christopher; Johnson, Levi; Moore, Kelsey; Stahman, Richard

    2015-08-01

    The Savannah River National Laboratory (SRNL) with the assistance of Georgia Regents University, completed a comparison of the U.S. Environmental Protection Agency's (U.S. EPA) environmental dosimetry code CAP88 PC V3.0 with the recently developed V4.0. CAP88 is a set of computer programs and databases used for estimation of dose and risk from radionuclide emissions to air. At the U.S. Department of Energy's Savannah River Site, CAP88 is used by SRNL for determining compliance with U.S. EPA's National Emission Standards for Hazardous Air Pollutants (40 CFR 61, Subpart H) regulations. Using standardized input parameters, individual runs were conducted for each radionuclide within its corresponding database. Some radioactive decay constants, human usage parameters, and dose coefficients changed between the two versions, directly causing a proportional change in the total effective dose. A detailed summary for select radionuclides of concern at the Savannah River Site (60Co, 137Cs, 3H, 129I, 239Pu, and 90Sr) is provided. In general, the total effective doses will decrease for alpha/beta emitters because of reduced inhalation and ingestion rates in V4.0. However, for gamma emitters, such as 60Co and 137Cs, the total effective doses will increase because of changes U.S. EPA made in the external ground shine calculations. PMID:26102326

  6. Comparison of U.S. Environmental Protection Agency’s CAP88 PC versions 3.0 and 4.0

    DOE PAGESBeta

    Jannik, Tim; Farfan, Eduardo B.; Dixon, Ken; Newton, Joseph; Sailors, Christopher; Johnson, Levi; Moore, Kelsey; Stahman, Richard

    2015-08-01

    The Savannah River National Laboratory (SRNL) with the assistance of Georgia Regents University, completed a comparison of the U.S. Environmental Protection Agency's (EPA) environmental dosimetry code CAP88 PC V3.0 with the recently developed V4.0. CAP88 is a set of computer programs and databases used for estimation of dose and risk from radionuclide emissions to air. At the U.S. Department of Energy's Savannah River Site, CAP88 is used by SRNL for determining compliance with EPA's National Emission Standards for Hazardous Air Pollutants (40 CFR 61, Subpart H) regulations. Using standardized input parameters, individual runs were conducted for each radionuclide within itsmore » corresponding database. Some radioactive decay constants, human usage parameters, and dose coefficients changed between the two versions, directly causing a proportional change in the total effective 137Cs, 3H, 129I, 239Pu, and 90Sr) is provided. In general, the total effective doses will decrease for alpha/beta emitters because of reduced inhalation and ingestion rates in V4.0. However, for gamma emitters, such as 60Co and 137Cs, the total effective doses will increase because of changes EPA made in the external ground shine calculations.« less

  7. Thin extractive membrane for monitoring actinides in aqueous streams.

    PubMed

    Chavan, Vivek; Paul, Sumana; Pandey, Ashok K; Kalsi, P C; Goswami, A

    2013-09-15

    Alpha spectrometry and solid state nuclear track detectors (SSNTDs) are used for monitoring ultra-trace amount of alpha emitting actinides in different aqueous streams. However, these techniques have limitations i.e. alpha spectrometry requires a preconcentration step and SSNTDs are not chemically selective. Therefore, a thin polymer inclusion membrane (PIM) supported on silanized glass was developed for preconcentraion and determination of ultra-trace concentration of actinides by α-spectrometry and SSNTDs. PIMs were formed by spin coating on hydrophobic glass slide or solvent casting to form thin and self-supported membranes, respectively. Sorption experiments indicated that uptakes of actinides in the PIM were highly dependent on acidity of solution i.e. Am(III) sorbed up to 0.1 molL(-1) HNO₃, U(VI) up to 0.5 molL(-1) HNO₃ and Pu(IV) from HNO₃ concentration as high as 4 molL(-1). A scheme was developed for selective sorption of target actinide in the PIM by adjusting acidity and oxidation state of actinide. The actinides sorbed in PIMs were quantified by alpha spectrometry and SSNTDs. For SSNTDs, neutron induced fission-fragment tracks and α-particle tracks were registered in Garware polyester and CR-39 for quantifications of natural uranium and α-emitting actinides ((241)Am/(239)Pu/(233)U), respectively. Finally, the membranes were tested to quantify Pu in 4 molL(-1) HNO3 solutions and synthetic urine samples. PMID:23747462

  8. Pu(V)O2+ adsorption and reduction by synthetic magnetite (Fe3O4).

    PubMed

    Powell, Brian A; Fjeld, Robert A; Kaplan, Daniel I; Coates, John T; Serkiz, Steven M

    2004-11-15

    Changes in aqueous- and solid-phase Pu oxidation state were monitored over time in magnetite (Fe3O4) suspensions containing 239Pu(V)-amended 0.01 M NaCl. Oxidation state distribution was determined by leaching of Pu into an aqueous phase followed by an ultrafiltration/solvent extraction technique. The capability of the technique to measure Pu oxidation state distribution was verified using 230Th(IV), 237Np(V), and 233U(VI) as oxidation state analogues. Reduction of Pu(V) was observed at all pH values (pH 3 to 8) and magnetite concentrations (10 to 100 m2 L(-1)). In the pH range 5 to 8, adsorption was a rate-limiting step, and reduction was mediated by the solid phase; at pH 3 reduction occurred in the aqueous phase. The overall reaction (describing both adsorption and reduction of Pu(V)) was found to be approximately first order with respect to the magnetite concentration and of order -0.34+/-0.02 with respect to the hydrogen ion concentration. Assuming first order dependence with respect to Pu, the overall reaction rate constant was calculated as k(rxn) = 4.79+/-0.62 x 10(-8) (m(-2) L)0.99(mol(-1) L)-0.34(s(-1)). The Pu(IV) solid-phase species became more stable over time. PMID:15573601

  9. Survey of plutonium and uranium atom ratios and activity levels in Mortandad Canyon

    SciTech Connect

    Gallaher, B.M.; Efurd, D.W.; Rokop, D.J.; Benjamin, T.M.; Stoker, A.K.

    1997-10-01

    For more than three decades, Mortandad Canyon has been the primary release area of treated liquid radioactive waste from the Los Alamos National Laboratory (Laboratory). In this survey, six water samples and seven stream sediment samples collected in Mortandad Canyon were analyzed by thermal ionization mass spectrometry to determine the plutonium and uranium activity levels and atom ratios. By measuring the {sup 240}Pu/{sup 239}Pu atom ratios, the Laboratory plutonium component was evaluated relative to that from global fallout. Measurements of the relative abundance of {sup 235}U and {sup 236}U were also used to identify non-natural components. The survey results indicate that the Laboratory plutonium and uranium concentrations in waters and sediments decrease relatively rapidly with distance downstream from the major industrial sources. Plutonium concentrations in shallow alluvial groundwater decrease by approximately 1,000-fold along a 3,000-ft distance. At the Laboratory downstream boundary, total plutonium and uranium concentrations were generally within regional background ranges previously reported. Laboratory-derived plutonium is readily distinguished from global fallout in on-site waters and sediments. The isotopic ratio data indicate off-site migration of trace levels of Laboratory plutonium in stream sediments to distances approximately two miles downstream of the Laboratory boundary.

  10. Survey of plutonium and uranium atom ratios and activity levels in Mortandad Canyon

    SciTech Connect

    Gallaher, B.M.; Benjamin, T.M.; Rokop, D.J.; Stoker, A.K.

    1997-09-22

    For more than three decades Mortandad Canyon has been the primary release area of treated liquid radioactive waste from the Los Alamos National Laboratory (Laboratory). In this survey, six water samples and seven stream sediment samples collected in Mortandad Canyon were analyzed by thermal ionization mass spectrometry (TIMS) to determine the plutonium and uranium activity levels and atom ratios. Be measuring the {sup 240}Pu/{sup 239}Pu atom ratios, the Laboratory plutonium component was evaluated relative to that from global fallout. Measurements of the relative abundance of {sup 235}U and {sup 236}U were also used to identify non-natural components. The survey results indicate the Laboratory plutonium and uranium concentrations in waters and sediments decrease relatively rapidly with distance downstream from the major industrial sources. Plutonium concentrations in shallow alluvial groundwater decrease by approximately 1000 fold along a 3000 ft distance. At the Laboratory downstream boundary, total plutonium and uranium concentrations were generally within regional background ranges previously reported. Laboratory derived plutonium is readily distinguished from global fallout in on-site waters and sediments. The isotopic ratio data indicates off-site migration of trace levels of Laboratory plutonium in stream sediments to distances approximately two miles downstream of the Laboratory boundary.

  11. Radioluminescence of solid neodymium-doped laser materials excited by {alpha}-particles and fission fragments

    SciTech Connect

    Seregina, E A; Seregin, A A

    2013-02-28

    The characteristics of radioluminescence of Nd{sup 3+} : Y{sub 3}Al{sub 5}O{sub 12} crystals and laser glasses under excitation by plutonium-239 ({sup 239}Pu) {alpha}-particles, as well as by {alpha}-particles and spontaneous fission fragments of californium-252 ({sup 252}Cf), are studied. The radioluminescence branching ratios {beta}{sub ij} for the transition from the {sup 2}F2{sub 5/2} level to the {sup 2S+1}L{sub J} levels in Nd{sup 3+} : Y{sub 3}Al{sub 5}O{sub 12} crystals are measured. Radioluminescence from the {sup 2}P{sub 3/2} level to low-lying levels is observed. The {beta}{sub ij} ratios for transitions from the high-lying {sup 2}F2{sub 5/2}, {sup 4}D{sub 3/2}, and {sup 2}P{sub 3/2} levels are theoretically calculated. The lifetimes of metastable levels of Nd{sup 3+} excited by {sup 252}Cf fission fragments are measured. The efficiency of the conversion of energy of {alpha}-particles and fission fragments to the energy of optical radiation of Nd{sup 3+} : Y{sub 3}Al{sub 5}O{sub 12} crystals and laser glasses is determined. (active media)

  12. Measured solubilities and speciations of neptunium, plutonium, and americium in a typical groundwater (J-13) from the Yucca Mountain region; Milestone report 3010-WBS 1.2.3.4.1.3.1

    SciTech Connect

    Nitsche, H.; Gatti, R.C.; Standifer, E.M.

    1993-07-01

    Solubility and speciation data are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are part of predictive transport models. Results are presented from solubility and speciation experiments of {sup 237}NpO{sub 2}{sup +}, {sup 239}Pu{sup 4+}, {sup 241}Am{sup 3+}/Nd{sup 3+}, and {sup 243}Am{sup 3+} in J-13 groundwater (from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site) at three different temperatures (25{degree}, 60{degree}, and 90{degree}C) and pH values (5.9, 7.0, and 8.5). The solubility-controlling steady-state solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined. The neptunium solubility decreased with increasing temperature and pH. Plutonium concentrations decreased with increasing temperature and showed no trend with pH. The americium solutions showed no clear solubility trend with increasing temperature and increasing pH.

  13. Confinement Vessel Assay System: Calibration and Certification Report

    SciTech Connect

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Gomez, Cipriano; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Vigil, Georgiana M.

    2012-07-17

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of SNM in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of {le} 100-g {sup 239}Pu equivalent in a vessel for safeguards termination. The system was calibrated in three different mass regions (low, medium, and high) to cover the entire plutonium mass range that will be assayed. The low mass calibration and medium mass calibration were verified for material positioned in the center of an empty vessel. The systematic uncertainty due to position bias was estimated using an MCNPX model to simulate the response of the system to material localized at various points along the inner surface of the vessel. The background component due to cosmic ray spallation was determined by performing measurements of an empty vessel and comparing to measurements in the same location with no vessel present. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements of CVs before and after cleanout.

  14. Organic complexant-enhanced mobility of toxic elements in low-level wastes. Annual report, July 1983-June 1984

    SciTech Connect

    Swanson, J.L.

    1984-11-01

    This report describes the initial results obtained in a project whose objective is to determine how and to what extent organic complexants affect the mobility of toxic elements in subsurface groundwaters at commercial low-level waste disposal sites. Generic soil components (e.g., hydrous oxides, silica, clays) are being employed so that the results will be broadly applicable. Organic complexants used in the nuclear industry are being emphasized. Data have been obtained with two radioactive (/sup 63/Ni and /sup 239/Pu) and one nonradioactive toxic element (Cd). Work with /sup 63/Ni has been emphasized; it was studied with five different generic soil components (hydrous ferric oxide, silica, titania, kaolinite, and montmorillonite) and five different complexants (EDTA, NTA, picolinate, citrate, and oxalate). EDTA was the complexant studied most extensively and hydrous ferric oxide was the most studied soil component. A wide diversity of effects of organic complexants on toxic elements sorption was observed. The effects vary not only among complexants, but also among toxic elements and among soil components. In some systems the complexant results in increased toxic element sorption (decreased mobility) while in other systems the complexant results in decreased toxic element sorption (increased mobility). 16 references, 14 figures, 5 tables.

  15. Organic complexant-enhanced mobility of toxic elements in low-level wastes

    SciTech Connect

    Swanson, J.L.

    1984-08-01

    This paper describes the results obtained during the recent activities of a project whose objective is to determine how and to what extent organic complexants affect the mobility of toxic elements in subsurface groundwaters at commercial low-level waste disposal sites. Generic soil components (e.g., hydrous oxides, silica, clays) are being employed so that the results will be broadly applicable. Data have been obtained with two radionuclides (/sup 63/Ni and /sup 239/Pu) and one nonradioactive toxic element (Cd). Work with /sup 63/Ni has been emphasized; it was studied with five different generic soil components (hydrous ferric oxide, silica, titania, kaolinite, and montmorillonite) and five different complexants (EDTA, NTA, picolinate, citrate, and oxalate). EDTA was the complexant studied most extensively and hydrous ferric oxide, Fe/sub 2/O/sub 3/.xH/sub 2/O, was the most studied soil component. A wide diversity of effects of organic complexants on toxic elements sorption was observed. The effects vary not only among complexants, but also among toxic elements and among soil components. In some systems the complexant results in increased toxic element sorption (decreased mobility) while in other systems the complexant results in decreased toxic element sorption (increased mobility). 5 references, 5 figures, 2 tables.

  16. BENCHMARKING UPGRADED HOTSPOT DOSE CALCULATIONS AGAINST MACCS2 RESULTS

    SciTech Connect

    Brotherton, Kevin

    2009-04-30

    The radiological consequence of interest for a documented safety analysis (DSA) is the centerline Total Effective Dose Equivalent (TEDE) incurred by the Maximally Exposed Offsite Individual (MOI) evaluated at the 95th percentile consequence level. An upgraded version of HotSpot (Version 2.07) has been developed with the capabilities to read site meteorological data and perform the necessary statistical calculations to determine the 95th percentile consequence result. These capabilities should allow HotSpot to join MACCS2 (Version 1.13.1) and GENII (Version 1.485) as radiological consequence toolbox codes in the Department of Energy (DOE) Safety Software Central Registry. Using the same meteorological data file, scenarios involving a one curie release of {sup 239}Pu were modeled in both HotSpot and MACCS2. Several sets of release conditions were modeled, and the results compared. In each case, input parameter specifications for each code were chosen to match one another as much as the codes would allow. The results from the two codes are in excellent agreement. Slight differences observed in results are explained by algorithm differences.

  17. Tritium concentrations in bees and honey at Los Alamos National Laboratory

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Salazar, J.G.

    1994-12-01

    Los Alamos National Laboratory (LANL) has maintained a network of honey bee colonies at LANL, perimeter (Los Alamos townsite and White Rock/Pajarito Acres) and regional (background) areas for over 15 years; the main objective of this honey bee network was to help determine the bioavailability of certain radionuclides in the environment. Of all the radionuclides studied ({sup 3}H, {sup 57}Co, {sup 7}Be, {sup 22}Na, {sup 54}Mn, {sup 83}Rb, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, {sup 90}Sr and total U), tritium was consistently detected in bees and was most readily transferred to the honey. In fact, honey collected from hives located at TA-21, TA-33, TA-50, TA-53, and TA-54 and from White Rock/Pajarito Acres contained significantly higher concentrations of {sup 3}H than regional background hives. Based on the average concentration of all radionuclides measured over the years, the effective dose equivalent (EDE) from consuming 5 kg (11 lb) of honey collected from Los Alamos (townsite) and White Rock/Pajarito Acres, after regional background has been subtracted, was 0.0186 ({+-}0.0507) and 0.0016 ({+-}0.0010) mrem/yr, respectively. The highest EDE, based on the mean + 2SD (95% confidence level), was 0.1200 mrem/y; this was <0.2% of the International Commission on Radiological Protection permissible dose limit of 100 mrem/yr from all pathways.

  18. Results of Gamma-Ray Measurements from a Recent Demonstration for Russian Technical Experts

    SciTech Connect

    Luke, S J; Archer, D E; Gosnell, T B; Lochner, R T; Morgan, J F; White, G K; Weitz, R

    2001-06-01

    In August 2001, a group of U.S. technical experts demonstrated an Attribute Measurement System with an Information Barrier (AMSIB) for a delegation of Russian technical experts. The purpose of the demonstration was to show that attributes of a classified plutonium item of potential interest to arms control and nonproliferation transparency regimes could be ascertained without releasing any sensitive information. For this demonstration, both gamma-ray and neutron attributes were determined. We consider only the gamma-ray attributes here. The specific plutonium attributes measured were the isotopic ratio of {sup 240}Pu to {sup 239}Pu, the ''age'' of the plutonium (time elapsed since the most recent chemical purification of the plutonium), and the absence of plutonium oxide in the item's storage container. In this paper, we briefly review the technologies employed for the attribute measurements used in the gamma-ray portion of the demonstration, concentrating on the results of the test measurements of the isotopic and age attributes made on unclassified items.

  19. Uranium comparison by means of AMS and ICP-MS and Pu and 137Cs results around an Italian Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    De Cesare, M.; Tims, S. G.; Fifield, L. K.

    2015-04-01

    Italy built and commissioned 4 nuclear power plants between 1958-1978, which delivered a total of 1500 MW. All four were closed down after the Chernobyl accident following a referendum in 1987. One of the plants was Garigliano, commissioned in 1959. This plant used a 160 MW BWR1 (SEU of 2.3 %) and was operational from 1964 to 1979, when it was switched off for maintenance. It was definitively stopped in 1982, and is presently being decommissioned. We report here details on the chemistry procedure and on the measurements for soil samples, collected up to 4.5 km from the Nuclear Plant. A comparison between uranium (238U) concentration as determined by means of AMS (Accelerator Mass Spectrometry) and by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) techniques respectively at the ANU (Australian National University) and at the Ecowise company in Canberra, Australia, is reported, as well as 236U and 239;240Pu concentration results detected by AMS. 236U/238U and 240Pu/239Pu isotopic ratios by means of AMS are also provided. A contamination from Chernobyl is visible in the 137Cs/239+240Pu activity ratio measurements.

  20. Insights into transport velocity of colloid-associated plutonium relative to tritium in porous media

    PubMed Central

    Xie, Jinchuan; Lu, Jiachun; Lin, Jianfeng; Zhou, Xiaohua; Xu, Qichu; Li, Mei; Zhang, Jihong

    2014-01-01

    Although faster transport velocities of colloid-associated actinides, bacteria, and virus than nonreactive solutes have been observed in laboratory and field experiments, some questions still need to be answered. To accurately determine the relative velocity (UPu/UT) of 239Pu and tritium representative of the bulk water, a conceptual model of electrostatic interactions coupled with the parabolic water velocity profile in pore channels is developed. Based on the expression for UPu/UT derived from this model, we study the effects of water flow rates and ionic strengths on the UPu/UT. Also, the velocity relationship between Pu, tritium and Sr2+ is explored. The results show that UPu/UT increased fairly linearly with decreasing water flow rates; UPu/UT declined approximately exponentially with increasing Na+ concentrations; the charge properties of colloid-associated Pu (negative), tritium (neutral) and Sr2+ (positive) had a close association with their transport velocities as UPu : UT : USr2+ = 1.41 : 1 : 0.579. PMID:24849695

  1. Deconvolution of mixed gamma emitters using peak parameters

    SciTech Connect

    Gadd, Milan S; Garcia, Francisco; Magadalena, Vigil M

    2011-01-14

    When evaluating samples containing mixtures of nuclides using gamma spectroscopy the situation sometimes arises where the nuclides present have photon emissions that cannot be resolved by the detector. An example of this is mixtures of {sup 241}Am and plutonium that have L x-ray emissions with slightly different energies which cannot be resolved using a high-purity germanium detector. It is possible to deconvolute the americium L x-rays from those plutonium based on the {sup 241}Am 59.54 keV photon. However, this requires accurate knowledge of the relative emission yields. Also, it often results in high uncertainties in the plutonium activity estimate due to the americium yields being approximately an order of magnitude greater than those for plutonium. In this work, an alternative method of determining the relative fraction of plutonium in mixtures of {sup 241}Am and {sup 239}Pu based on L x-ray peak location and shape parameters is investigated. The sensitivity and accuracy of the peak parameter method is compared to that for conventional peak decovolution.

  2. Calculation of the minimum critical mass of fissile nuclides

    SciTech Connect

    Wright, R Q; Hopper, Calvin Mitchell

    2008-01-01

    The OB-1 method for the calculation of the minimum critical mass of fissile actinides in metal/water systems was described in a previous paper. A fit to the calculated minimum critical mass data using the extended criticality parameter is the basis of the revised method. The solution density (grams/liter) for the minimum critical mass is also obtained by a fit to calculated values. Input to the calculation consists of the Maxwellian averaged fission and absorption cross sections and the thermal values of nubar. The revised method gives more accurate values than the original method does for both the minimum critical mass and the solution densities. The OB-1 method has been extended to calculate the uncertainties in the minimum critical mass for 12 different fissile nuclides. The uncertainties for the fission and capture cross sections and the estimated nubar uncertainties are used to determine the uncertainties in the minimum critical mass, either in percent or grams. Results have been obtained for U-233, U-235, Pu-236, Pu-239, Pu-241, Am-242m, Cm-243, Cm-245, Cf-249, Cf-251, Cf-253, and Es-254. Eight of these 12 nuclides are included in the ANS-8.15 standard.

  3. Radionuclide and heavy metal concentrations in soil, vegetation, and fish collected around and within Tsicoma Lake in Santa Clara Canyon

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Naranjo, L. Jr.

    1996-03-01

    Radionuclide ({sup 3}H, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, total U) and heavy metal (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, Tl) contents were determined in soil, vegetation (overstory and understory), and fish (rainbow trout) collected around and within Tsicoma Lake in Santa Clara Canyon in 1995. All heavy metal and most radionuclide contents around or within the lake, except for U in soil, vegetation, and fish, were within or just above upper limit background. Detectable levels (where the analytical result was greater than two times counting uncertainty) of U in soils, vegetation, and fish were found in slightly higher concentrations than in background samples. Overall, however, maximum total committed effective dose equivalent (CEDE)(95% confidence level)--based on consumption of 46 lb of fish--from Tsicoma Lake (0.066 mrem/y) was within the maximum total CEDE from the ingestion of fish from the Mescalero National Fish Hatchery (background)(0.113 mrem/y).

  4. Radionuclide concentrations in elk that winter on Los Alamos National Laboratory lands. Revision

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.A.; Salazar, J.G.

    1994-07-01

    Elk spend the winter in areas at Los Alamos National Laboratory (LANL) that may contain radioactivity above natural and/or worldwide fallout levels. This study was initiated to determine the levels of {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium in various tissues (brain, hair, heart, jawbone, kidneys, leg bone, liver, and muscle) of adult cow elk that use LANL lands during the fall/winter months. No significant differences in radionuclide contents were detected in any of the tissue samples collected from elk on LANL lands as compared with elk collected from off-site locations. The total effective (radiation) dose equivalent a person would receive from consuming 3.2 lb of heart, 5.6 lb of liver, and 226 lb of muscle from elk that winter on LANL lands, after natural background has been subtracted, was 0.00008, 0.0001, and 0.008 mrem/yr, respectively. The highest dose was less than 0.01% of the International Commission on Radiological Protection permissible dose limit for protecting the public.

  5. Radionuclide concentrations in game and nongame fish upstream and downstream of Los Alamos National Laboratory: 1981 to 1993

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Salazar, J.G.

    1994-08-01

    Radionuclide concentrations were determined in game (surface-feeding) and nongame (bottom-feeding) fish collected from reservoirs upstream (Abiquiu, Heron, and El Vado) and downstream (Cochiti) of Los Alamos National Laboratory from 1981 to 1993. The average levels of {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, and {sup 239}Pu in game and nongame fish collected from Cochiti reservoir were not significantly different in fish collected from reservoirs upstream of the Laboratory. Total uranium was the only radionuclide that was found to be significantly higher n both game and nongame fish from Cochiti as compared to fish from Abiquiu, Heron, and El Vado. Uranium concentrations in fish collected from Cochiti, however, significantly decreased from 1981 to 1993, and no evidence of depleted uranium was found in fish samples collected from Cochiti in 1993. Based on the average concentration of radionuclides over the year the effective (radiation) dose equivalent from consuming 46 lb of game fish and nongame fish from Cochiti reservoir after natural background has been subtracted was 0.005 and 0.009 mrem/yr, respectively. The highest dose was <0.01% of the International Commission on Radiological Protection (ICRP) permissible dose limit for protecting members of the public.

  6. Development for fissile assay in recycled fuel using lead slowing down spectrometer

    SciTech Connect

    Lee, Yong Deok; Je Park, C.; Kim, Ho-Dong; Song, Kee Chan

    2013-07-01

    A future nuclear energy system is under development to turn spent fuels produced by PWRs into fuels for a SFR (Sodium Fast Reactor) through the pyrochemical process. The knowledge of the isotopic fissile content of the new fuel is very important for fuel safety. A lead slowing down spectrometer (LSDS) is under development to analyze the fissile material content (Pu{sup 239}, Pu{sup 241} and U{sup 235}) of the fuel. The LSDS requires a neutron source, the neutrons will be slowed down through their passage in a lead medium and will finally enter the fuel and will induce fission reactions that will be analysed and the isotopic content of the fuel will be then determined. The issue is that the spent fuel emits intense gamma rays and neutrons by spontaneous fission. The threshold fission detector screens the prompt fast fission neutrons and as a result the LSDS is not influenced by the high level radiation background. The energy resolution of LSDS is good in the range 0.1 eV to 1 keV. It is also the range in which the fission reaction is the most discriminating for the considered fissile isotopes. An electron accelerator has been chosen to produce neutrons with an adequate target through (e{sup -},γ)(γ,n) reactions.

  7. Effect of quench on alpha/beta pulse shape discrimination of liquid scintillation cocktails.

    PubMed

    DeVol, Timothy A; Theisen, Christopher D; DiPrete, David P

    2007-05-01

    The objectives of this paper are (1) to illustrate that knowledge of the external quench parameter is insufficient to properly setup a pulse shape discriminating liquid scintillation counter (LSC) for quantitative measurement, (2) to illustrate dependence on pulse shape discrimination on the radionuclide (more than just radiation and energy), and (3) to compare the pulse shape discrimination (PSD) of two commercial instruments. The effects various quenching agents, liquid scintillation cocktails, radionuclides, and LSCs have on alpha/beta pulse shape discriminating liquid scintillation counting were quantified. Alpha emitting radionuclides (239)Pu and (241)Am and beta emitter (90)Sr/(90)Y were investigated to quantify the nuclide dependence on alpha/beta pulse shape discrimination. Also, chemical and color quenching agents, nitromethane, nitric acid, and yellow dye impact on alpha/beta pulse shape discrimination using PerkinElmer Optiphase "HiSafe" 2 and 3, and Ultima Gold AB liquid scintillation cocktails were determined. The prepared samples were counted on the PerkinElmer Wallac WinSpectral 1414 alpha/beta pulse shape discriminating LSC. It was found that for the same level of quench, as measured by the external quench parameter, different quench agents influenced the pulse shape discrimination and the pulse shape discrimination parameters differently. The radionuclide also affects alpha/beta pulse shape discrimination. By comparison with the PerkinElmer Tri-carb 3150 TR/AB, the Wallac 1414 exhibited better pulse shape discrimination capability under the same experimental conditions. PMID:17440321

  8. Waste inspection tomography (WIT)

    SciTech Connect

    Bernardi, R.T.

    1996-12-31

    WIT is a self-sufficient mobile semitrailer for nondestructive evaluation and nondestructive assay of nuclear waste drums using x-ray and gamma-ray tomography. The recently completed Phase I included the design, fabrication, and initial testing of all WIT subsystems installed on-board the trailer. Initial test results include 2 MeV digital radiography, computed tomography, Anger camera imaging, single photon emission computed tomography, gamma-ray spectroscopy, collimated gamma scanning, and active and passive computed tomography using a 1.4 mCi source of {sup 166}Ho. These techniques were initially demonstrated on a 55-gallon phantom drum with 3 simulated waste matrices of combustibles, heterogeneous metals, and cement using check sources of gamma active isotopes such as {sup 137}Cs and {sup 133}Ba with 9-250 {mu}Ci activities. Waste matrix identification, isotopic identification, and attenuation-corrected gamma activity determination were demonstrated nondestructively and noninvasively in Phase I. Currently ongoing Phase II involves DOE site field test demonstrations at LLNL, RFETS, and INEL with real nuclear waste drums. Current WIT experience includes 55 gallon drums of cement, graphite, sludge, glass, metals, and combustibles. Thus far WIT has inspected drums with 0-20 gms of {sup 239}Pu.

  9. The sensitivity of different environments to radioactive contamination.

    PubMed

    Tracy, B L; Carini, F; Barabash, S; Berkovskyy, V; Brittain, J E; Chouhan, S; Eleftheriou, G; Iosjpe, M; Monte, L; Psaltaki, M; Shen, J; Tschiersch, J; Turcanu, C

    2013-08-01

    This paper describes modelling calculations carried out to determine the sensitivity of various rural and semi-natural environments to radionuclide contamination by (137)Cs, (90)Sr, and (131)I released during a major nuclear accident. Depositions of 1000 Bq/m(3) were assumed for each radionuclide. Four broad types of environments were considered: agricultural, forest or tundra, freshwater aquatic, and coastal marine. A number of different models were applied to each environment. The annual dose to a human population receiving most or all of its food and drinking water from a given environment was taken as a broad measure of sensitivity. The results demonstrated that environmental sensitivity was highly radionuclide specific, with (137)Cs generally giving the highest doses during the first year, especially for adults, in terrestrial and freshwater pathways. However, in coastal marine environments, (131)I and (239)Pu were more significant. Sensitivity was time dependent with doses for the first year dominating those for the 2nd and 10th years after deposition. In agricultural environments the ingestion dose from (137)Cs was higher for adults than other age groups, whereas for (90)Sr and (131)I, the ingestion dose was highest for infants. The dependence of sensitivity on social and economic factors such as individual living habits, food consumption preferences, and agricultural practices is discussed. PMID:23517769

  10. Solubility and speciation results from oversaturation experiments on neptunium, plutonium and americium in a neutral electrolyte with a total carbonate similar to water from Yucca Mountain Region Well UE- 25p No. 1

    SciTech Connect

    Torretto, P.; Becraft, K.; Prussin, T.; Roberts, K.; Carpenter, S.; Hobart, D.; Nitsche, H.

    1995-12-01

    Solubility and speciation are important in understanding aqueous radionuclide transport through the geosphere. They define the source term for transport retardation processes such as sorption and colloid formation. Solubility and speciation data are useful in verifying the validity of geochemical codes that are a part of predictive transport models. Solubility experiments will approach solution equilibrium from both oversaturation and undersaturation. In these experiments, we have approached the solubility equilibrium from oversaturation, Results are given for solubility and speciation experiments from oversaturation of {sup 237} NpO{sub 2}{sup +} {sup 239}Pu{sup 4+}, and {sup 241}Am{sup 3+}/Nd{sup 3+} in a neutral electrolyte containing a total carbonate concentration similar to groundwater from the Yucca Mountain region, Nevada, which is being investigated as a potential high-level nuclear waste disposal site, at 25{degrees}C and three pH values. In these experiments, the solubilitycontrolling steady-state solids were identified and the speciation and/or oxidation states present in the supernatant solutions were determined.

  11. High-Resistivity Semi-insulating AlSb on GaAs Substrates Grown by Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Vaughan, E. I.; Addamane, S.; Shima, D. M.; Balakrishnan, G.; Hecht, A. A.

    2016-04-01

    Thin-film structures containing AlSb were grown using solid-source molecular beam epitaxy and characterized for material quality, carrier transport optimization, and room-temperature radiation detection response. Few surface defects were observed, including screw dislocations resulting from shear strain between lattice-mismatched layers. Strain was also indicated by broadening of the AlSb peak in x-ray diffraction measurements. Threading dislocations and interfacial misfit dislocations were seen with transmission electron microscopy imaging. Doping of the AlSb layer was introduced during growth using GaTe and Be to determine the effect on Hall transport properties. Hall mobility and resistivity were largest for undoped AlSb samples, at 3000 cm2/V s and 106 Ω cm, respectively, and increased doping levels progressively degraded these values. To test for radiation response, p-type/intrinsic/ n-type (PIN) diode structures were grown using undoped AlSb on n-GaAs substrates, with p-GaSb cap layers to protect the AlSb from oxidation. Alpha-particle radiation detection was achieved and spectra were produced for 241Am, 252Cf, and 239Pu sources. Reducing the detector surface area increased the pulse height observed, as expected based on voltage-capacitance relationships for diodes.

  12. Reactor physics studies for assessment of tramp uranium methods

    SciTech Connect

    Grimm, P.; Vasiliev, A.; Wieselquist, W.; Ferroukhi, H.; Ledergerber, G.

    2012-07-01

    This paper presents calculation studies towards validation of a methodology for estimations of the tramp uranium mass from water chemistry measurements. Particular emphasis is given to verify, from a reactor physics point of view, the justification basis for the so-called 'Pu-based model' versus the 'U-based model' as a key assumption for the methodology. The computational studies are carried out for a typical BWR fuel assembly with CASMO-5M and MCNPX. By approximating the evolution of fissile nuclides and the fraction of {sup 235}U fissions to total fissions in different zones of a fuel rod, including tramp uranium on the clad surface, it is found that Pu gives the dominant contribution to fissions for tramp uranium after an irradiation on the outer clad surface of at least one cycle in a BWR. Thus, the use of the so-called Pu model for the determination of the tramp uranium mass (this means in particular using the yields for {sup 239}Pu fission) appears justified in the cases considered. On that basis, replacing the older U model by a Pu model is recommended. (authors)

  13. Self-Determination and Choice

    ERIC Educational Resources Information Center

    Wehmeyer, Michael L.; Abery, Brian H.

    2013-01-01

    Promoting self-determination and choice opportunities for people with intellectual and developmental disabilities has become best practice in the field. This article reviews the research and development activities conducted by the authors over the past several decades and provides a synthesis of the knowledge in the field pertaining to efforts to…

  14. Cesium Eluate Physical Property Determination

    SciTech Connect

    Baich, M.A.

    2001-02-13

    Two bench-scale process simulations of the proposed cesium eluate evaporation process of concentrating eluate produced in the Hanford Site Waste Treatment Plant were conducted. The primary objective of these experiments was to determine the physical properties and the saturation concentration of the eluate evaporator bottoms while producing condensate approximately 0.50 molar HN03.

  15. The Determinants of Pay Satisfaction

    ERIC Educational Resources Information Center

    Dyer, Lee; Theriault, Roland

    1976-01-01

    Through a study of American and Canadian managers, tested the utility of Lawler's model of the determinants of pay satisfaction and the value of adding to Lawler's model a category of variables for perceptions of pay-system administration. The study findings are then used to develop a modified model. For availability see EA 507 670. (Author/JG)

  16. Determining Salinity by Simple Means.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This paper describes the construction and use of a simple salinometer. The salinometer is composed, mainly, of a milliammeter and a battery and uses the measurement of current flow to determine the salinity of water. A complete list of materials is given, as are details of construction and operation of the equipment. The use of the salinometer in…

  17. Self-Determination: First Steps.

    ERIC Educational Resources Information Center

    Thompson, Morris

    The year 1974 marked the first full year in which the Bureau of Indian Affairs (BIA) officially embarked on a policy of advising and assisting American Indian tribes to assume the administration of their own affairs (self-determination). It seeks to strengthen and stabilize tribal governments while continuing to maintain and fulfill its trust…

  18. Determinants and Polynomial Root Structure

    ERIC Educational Resources Information Center

    De Pillis, L. G.

    2005-01-01

    A little known property of determinants is developed in a manner accessible to beginning undergraduates in linear algebra. Using the language of matrix theory, a classical result by Sylvester that describes when two polynomials have a common root is recaptured. Among results concerning the structure of polynomial roots, polynomials with pairs of…

  19. Formulas for determining rotational constants

    NASA Astrophysics Data System (ADS)

    Guelachvili, G.

    This document is part of Subvolume B `Linear Triatomic Molecules', Part 9, of Volume 20 `Molecular Constants mostly from Infrared Spectroscopy' of Landolt-Börnstein Group II `Molecules and Radicals'. Part of the introduction, it states formulas for determining rotational constants, band center, band origin, and quadrupole coupling. Specific comments relate to BHO (HBO) and COS (OCS).

  20. Inulin determination for food labeling.

    PubMed

    Zuleta, A; Sambucetti, M E

    2001-10-01

    Inulin and oligofructose exhibit valuable nutritional and functional attributes, so they are used as supplements as soluble fiber or as macronutrient substitutes. As classic analytical methods for dietary fiber measurement are not effective, several specific methods have been proposed. These methods measure total fructans and are based on one or more enzymatic sample treatments and determination of released sugars. To determine inulin for labeling purposes, we developed an easy and rapid anion-exchange high-performance liquid chromatography (HPLC) method following water extraction of inulin. HPLC conditions included an Aminex HPX- 87C column (Bio-Rad), deionized water at 85 degrees C as the mobile phase and a refractive index detector. The tested foods included tailor-made food products containing known amounts of inulin and commercial products (cookies, milk, ice creams, cheese, and cereal bars). The average recovery was 97%, and the coefficient of variation ranged from 1.1 to 5% in the food matrixes. The obtained results showed that this method provides an easier, faster and cheaper alternative than previous techniques for determining inulin with enough accuracy and precision for routine labeling purposes by direct determination of inulin by HPLC with refractive index detection. PMID:11599989

  1. Plasma digital density determining device

    DOEpatents

    Sprott, Julien C.; Lovell, Thomas W.; Holly, Donald J.

    1976-01-01

    The density of a decaying plasma in an electrically conducting enclosure is determined by applying an excitation to the cavity formed by the enclosure and counting digitally the number of resonant frequencies traversed by the combination of the cavity and the decaying plasma.

  2. Cohesin in determining chromosome architecture

    SciTech Connect

    Haering, Christian H.; Jessberger, Rolf

    2012-07-15

    Cells use ring-like structured protein complexes for various tasks in DNA dynamics. The tripartite cohesin ring is particularly suited to determine chromosome architecture, for it is large and dynamic, may acquire different forms, and is involved in several distinct nuclear processes. This review focuses on cohesin's role in structuring chromosomes during mitotic and meiotic cell divisions and during interphase.

  3. Self-Determination and Bilingualism

    ERIC Educational Resources Information Center

    Landry, Rodrigue; Allard, Real; Deveau, Kenneth

    2009-01-01

    This article focuses on additive bilingualism for minority group children, more specifically the development of strong literacy skills in English and in the children's language. The personal autonomization language learning (PALL) model is presented. It specifies eight testable hypotheses. Self-determination theory (SDT) is central in the PALL…

  4. Determining Readability with a Microcomputer.

    ERIC Educational Resources Information Center

    Kennedy, Keith

    1985-01-01

    Discusses history of the development of computer software to determine material readability and general design of readability software. Tables present summaries of: (1) parameters used by selected readability scales and their grade level applications; and (2) microcomputer software programs available, including readability techniques included in…

  5. Videos Determine the Moon's "g"

    ERIC Educational Resources Information Center

    Persson, J. R.; Hagen, J. E.

    2011-01-01

    Determining the acceleration of a free-falling object due to gravity is a standard experiment in physics. Different methods to do this have been developed over the years. This article discusses the use of video-analysis tools as another method. If there is a video available and a known scale it is possible to analyse the motion. The use of video…

  6. Means of determining extrusion temperatures

    DOEpatents

    McDonald, Robert E.; Canonico, Domenic A.

    1977-01-01

    In an extrusion process comprising the steps of fabricating a metal billet, heating said billet for a predetermined time and at a selected temperature to increase its plasticity and then forcing said heated billet through a small orifice to produce a desired extruded object, the improvement comprising the steps of randomly inserting a plurality of small metallic thermal tabs at different cross sectional depths in said billet as a part of said fabricating step, and examining said extruded object at each thermal tab location for determining the crystal structure at each extruded thermal tab thus revealing the maximum temperature reached during extrusion in each respective tab location section of the extruded object, whereby the thermal profile of said extruded object during extrusion may be determined.

  7. Low thrust orbit determination program

    NASA Technical Reports Server (NTRS)

    Hong, P. E.; Shults, G. L.; Huling, K. R.; Ratliff, C. W.

    1972-01-01

    Logical flow and guidelines are provided for the construction of a low thrust orbit determination computer program. The program, tentatively called FRACAS (filter response analysis for continuously accelerating spacecraft), is capable of generating a reference low thrust trajectory, performing a linear covariance analysis of guidance and navigation processes, and analyzing trajectory nonlinearities in Monte Carlo fashion. The choice of trajectory, guidance and navigation models has been made after extensive literature surveys and investigation of previous software. A key part of program design relied upon experience gained in developing and using Martin Marietta Aerospace programs: TOPSEP (Targeting/Optimization for Solar Electric Propulsion), GODSEP (Guidance and Orbit Determination for SEP) and SIMSEP (Simulation of SEP).

  8. Luminosity determination at proton colliders

    NASA Astrophysics Data System (ADS)

    Grafström, P.; Kozanecki, W.

    2015-03-01

    Luminosity is a key parameter in any particle collider, and its precise determination has proven particularly challenging at hadron colliders. After introducing the concept of luminosity in its multiple incarnations and offering a brief survey of the pp and p p bar colliders built to date, this article outlines the various methods that have been developed for relative-luminosity monitoring, as well as the complementary approaches considered for establishing an absolute luminosity scale. This is followed by a survey, from both a historical and a technical perspective, of luminosity determination at the ISR, the S p p ¯ S, the Tevatron, RHIC and the LHC. For each of these, we first delineate the interplay between the experimental context, the specificities of the accelerator, and the precision targets suggested by the physics program. We then detail how the different methods were applied to specific experimental environments and how successfully they meet the precision goals.

  9. [Immunochemical determination of human lactoferrin].

    PubMed

    German, G P; Lavrova, N V; Sherer, L A

    1983-09-01

    The immunochemically pure preparation of lactoferrin was isolated from human colostrum and used for the immunization of animals with a view of obtaining antiserum, and also as a reference preparation for the determination of the content of lactoferrin in the standard. The monospecific antiserum to lactoferrin, obtained as the result of this procedure, was used for the determination of the content of lactoferrin in samples of human milk by the method of radial immunodiffusion. Through the content of lactoferrin in human milk showed considerable fluctuations, its level essentially decreased on the second week of lactation. In cases of the microbial contamination of milk the tendency towards an increase in the content of lactoferrin was observed irrespective of the time of lactation. PMID:6415975

  10. Asteroid candidates for mass determination

    NASA Astrophysics Data System (ADS)

    Galád, A.

    2001-04-01

    The first 9511 numbered asteroids are studied in terms of their mutual closest approaches and encounter velocities during the period from November 6, 1967, to September 13, 2023. Several large asteroids (diameter 200 km and above) were (will be) encountered by smaller counterparts within a distance of 0.0200 AU. Thus, they are possible candidates for mass determination by the astrometrical method. Similarly, the search for effective perturbers is extended to even smaller asteroids for the much closer separation distance of 0.0020 AU and below. Only the simplified method for evaluation of observable effects on a perturbed body is used. Asteroid masses alone are not computed here. But a stronger criterion to reveal pairs for this purpose in comparison to some specially devoted papers should compensate for the difference and act as a reliable test. The best candidates for mass determination at present are asteroids (1), (2), (4), (10), (11), (24), (52) and (65). This list may be extended by at least (29) in the next 5 years and by many others in the next two decades. Several other strong perturbers from the last three decades are not included in the list, while there is still only a limited number of (or no) precise and reliable observations of perturbed asteroids before a close encounter. It seems that a perturbation by (10) is at least as effective as that by (2) and could be included in asteroid orbit determination in the future. Except for their bulk density determinations (knowing the size), the masses of perturbers could occasionally be used to improve the precision of the computed orbit for perturbed large-numbered and unnumbered asteroids as well.

  11. In-flight thrust determination

    NASA Technical Reports Server (NTRS)

    Abernethy, Robert B.; Adams, Gary R.; Ascough, John C.; Baer-Riedhart, Jennifer L.; Balkcom, George H.; Biesiadny, Thomas

    1986-01-01

    The major aspects of processes that may be used for the determination of in-flight thrust are reviewed. Basic definitions are presented as well as analytical and ground-test methods for gathering data and calculating the thrust of the propulsion system during the flight development program of the aircraft. Test analysis examples include a single-exhaust turbofan, an intermediate-cowl turbofan, and a mixed-flow afterburning turbofan.

  12. Determinism in synthesized chaotic waveforms.

    PubMed

    Corron, Ned J; Blakely, Jonathan N; Hayes, Scott T; Pethel, Shawn D

    2008-03-01

    The output of a linear filter driven by a randomly polarized square wave, when viewed backward in time, is shown to exhibit determinism at all times when embedded in a three-dimensional state space. Combined with previous results establishing exponential divergence equivalent to a positive Lyapunov exponent, this result rigorously shows that such reverse-time synthesized waveforms appear equally to have been produced by a deterministic chaotic system. PMID:18517561

  13. Range determination for scannerless imaging

    DOEpatents

    Muguira, Maritza Rosa; Sackos, John Theodore; Bradley, Bart Davis; Nellums, Robert

    2000-01-01

    A new method of operating a scannerless range imaging system (e.g., a scannerless laser radar) has been developed. This method is designed to compensate for nonlinear effects which appear in many real-world components. The system operates by determining the phase shift of the laser modulation, which is a physical quantity related physically to the path length between the laser source and the detector, for each pixel of an image.

  14. Method for determining gene knockouts

    DOEpatents

    Maranas, Costas D.; Burgard, Anthony R.; Pharkya, Priti

    2011-09-27

    A method for determining candidates for gene deletions and additions using a model of a metabolic network associated with an organism, the model includes a plurality of metabolic reactions defining metabolite relationships, the method includes selecting a bioengineering objective for the organism, selecting at least one cellular objective, forming an optimization problem that couples the at least one cellular objective with the bioengineering objective, and solving the optimization problem to yield at least one candidate.

  15. Method for determining gene knockouts

    DOEpatents

    Maranas, Costa D; Burgard, Anthony R; Pharkya, Priti

    2013-06-04

    A method for determining candidates for gene deletions and additions using a model of a metabolic network associated with an organism, the model includes a plurality of metabolic reactions defining metabolite relationships, the method includes selecting a bioengineering objective for the organism, selecting at least one cellular objective, forming an optimization problem that couples the at least one cellular objective with the bioengineering objective, and solving the optimization problem to yield at least one candidate.

  16. Gender determination from pulpal tissue

    PubMed Central

    Khorate, Manisha M.; Dhupar, Anita; Ahmed, Junaid; Dinkar, Ajit D.

    2014-01-01

    Objective: To evaluate the diagnostic performance of X (Barr body [BB]) and Y (F body [FB]) chromosomes observed in dental pulp tissue for gender determination of an individual. Materials and Methods: The study was carried out on 100 teeth (50 male and 50 female), which were indicated for extraction. The teeth were sectioned at various intervals (within 12 h to 49 days post-extraction), and the pulpal tissue was obtained. Two slides for each pulp tissue were prepared, one for 5% Quinacrine dihydrochloride stain (FB) and the other for Hemotoxylin and Eosin stain (BB). The slides were then observed under the fluorescent microscope for FB and under the light microscope for the BB respectively. Results: Gender determination from human pulp is possible up to 7 weeks. The percentage of FB and BB decrease gradually as the time interval increases. Further, an equation was derived from the data based on the canonical discriminant function coefficients. Conclusion: The determination of gender based on a joint search for the presence or absence of X (BB) and Y (FB) Chromosome is a reliable and cost-effective technique. PMID:25125918

  17. Meteorological determinants of air quality

    NASA Astrophysics Data System (ADS)

    Turoldo, F.; Del Frate, S.; Gallai, I.; Giaiotti, D. B.; Montanari, F.; Stel, F.; Goi, D.

    2010-09-01

    Air quality is the result of complex phenomena, among which the major role is played by human emissions of pollutants. Atmospheric processes act as determinants, e.g., modulating, dumping or amplifying the effects of emissions as an orchestra's director does with musical instruments. In this work, a series of small-scale and meso-scale meteorological determinants of air-quality are presented as they are observed in an area characterized by complex orography (Friuli Venezia Giulia, in the north-eastern side of Italy). In particular, attention is devoted to: i) meso-scale flows favouring the persistence of high concentrations of particulate matter; ii) meso-scale periodic flows (breezes) favouring high values of particulate matter; iii) local-scale thermodynamic behaviour favouring high atmospheric values of nitrogen oxides. The effects of these different classes of determinants are shown through comparisons between anthropic emissions (mainly traffic) and ground-based measurements. The relevance of complex orography (relatively steep relieves near to the sea) is shown for the meso-scale flows and, in particular, for local-scale periodic flows, which favour the increase of high pollutants concentrations mainly in summer, when the breezes regime is particularly relevant. Part of these results have been achieved through the ETS - Alpine Space EU project iMONITRAF!

  18. Determinism, indeterminism, and explanatory bias.

    PubMed

    Targett, M

    1997-12-01

    Actions are a subclass of human behaviours which are distinguished, on a modest view, by certain antecedent mental and neural processes and events, including desires and beliefs. Libertarian philosophies have taken a less modest view, according to which some actions come under the influence of individual persons in a way distinct from being the necessary effect of a sequence of psychoneural events. Determinism claims necessary connections between sequences of events and conditions, including those sequences that involve desires and beliefs and subsequent actions. Even if a certain interpretation of modern physics shows determinism to be false, the sense of personal influence over action which libertarians have remains obscure. It is not enlightened by the physicist's idea of inexplicable fluctuations between courses of events with greater or lesser probabilities. If libertarianism remains obscure, so do the grounds for an approach to explaining behaviour which might be called "explanatory individualism". According to the latter stance, the local outcomes of actions and larger social tendencies are only properly explained in terms of the choices of individuals, rather than, for example, their neural or environmental antecedents. Again, bare indeterminism will not help to supply the required grounds. A more justifiable stance is "explanatory pluralism", a doctrine which denies the intrinsic priority of individualistic modes of explanation over those which focus on psychoneural, environmental, social or genetic conditions. It is stressed that on a sensible pluralism, any determinism which correctly describes the history of actions would be no more "genetic", than indeterminism could be "individualistic". PMID:9421834

  19. 19 CFR 351.205 - Preliminary determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determinations, postponement of preliminary determinations, notices of preliminary determinations, and the... its injury determination. (e) Postponement at the request of the petitioner. A petitioner must submit a request for postponement of the preliminary determination (see section 703(c)(1)(A) or section...

  20. Soil carbon determination by thermogravimetrics

    PubMed Central

    Pallasser, Robert; McBratney, Alex B.

    2013-01-01

    Determination of soil constituents and structure has a vital role in agriculture generally. Methods for the determination of soil carbon have in particular gained greater currency in recent times because of the potential that soils offer in providing offsets for greenhouse gas (CO2-equivalent) emissions. Ideally, soil carbon which can also be quite diverse in its makeup and origin, should be measureable by readily accessible, affordable and reliable means. Loss-on-ignition is still a widely used method being suitably simple and available but may have limitations for soil C monitoring. How can these limitations be better defined and understood where such a method is required to detect relatively small changes during soil-C building? Thermogravimetric (TGA) instrumentation to measure carbonaceous components has become more interesting because of its potential to separate carbon and other components using very precise and variable heating programs. TGA related studies were undertaken to assist our understanding in the quantification of soil carbon when using methods such as loss-on-ignition. Combining instrumentation so that mass changes can be monitored by mass spectrometer ion currents has elucidated otherwise hidden features of thermal methods enabling the interpretation and evaluation of mass-loss patterns. Soil thermogravimetric work has indicated that loss-on-ignition methods are best constrained to temperatures from 200 to 430 °C for reliable determination for soil organic carbon especially where clay content is higher. In the absence of C-specific detection where mass only changes are relied upon, exceeding this temperature incurs increasing contributions from inorganic sources adding to mass losses with diminishing contributions related to organic matter. The smaller amounts of probably more recalcitrant organic matter released at the higher temperatures may represent mineral associated material and/or simply more refractory forms. PMID:23638398

  1. Geostationary orbit determination using SATRE

    NASA Astrophysics Data System (ADS)

    Lei, Hui; Li, ZhiGang; Yang, XuHai; Wu, WenJun; Cheng, Xuan; Yang, Ying; Feng, ChuGang

    2011-09-01

    A new strategy of precise orbit determination (POD) for GEO (Geostationary Earth Orbit) satellite using SATRE (SAtellite Time and Ranging Equipment) is presented. Two observation modes are proposed and different channels of the same instruments are used to construct different observation modes, one mode receiving time signals from their own station and the other mode receiving time signals from each other for two stations called pairs of combined observations. Using data from such a tracking network in China, the results for both modes are compared. The precise orbit determination for the Sino-1 satellite using the data from 6 June 2005 to 13 June 2005 has been carried out in this work. The RMS (Root-Mean-Square) of observing residuals for 3-day solutions with the former mode is better than 9.1 cm. The RMS of observing residuals for 3-day solutions with the latter mode is better than 4.8 cm, much better than the former mode. Orbital overlapping (3-day orbit solution with 1-day orbit overlap) tests show that the RMS of the orbit difference for the former mode is 0.16 m in the radial direction, 0.53 m in the along-track direction, 0.97 m in the cross-track direction and 1.12 m in the 3-dimension position and the RMS of the orbit difference for the latter mode is 0.36 m in the radial direction, 0.89 m in the along-track direction, 1.18 m in the cross-track direction and 1.52 m in the 3-dimension position, almost the same as the former mode. All the experiments indicate that a meter-level accuracy of orbit determination for geostationary satellite is achievable.

  2. Determination of uranium in zircon

    USGS Publications Warehouse

    Cuttitta, F.; Daniels, G.J.

    1959-01-01

    A routine fluorimetric procedure is described for the determination of trace amounts of uranium in zircon. It employs the direct extraction of uranyl nitrate with ethyl acetate using phosphate as a retainer for zirconium. Submicrogram amounts or uranium are separated in the presence of 100,000 times the amount of zirconium. The modified procedure has been worked out using synthetic mixtures of known composition and zircon. Results of analyses have an accuracy of 97-98% of the contained uranium and a standard deviation of less than 2.5%. ?? 1959.

  3. Liquid chromatographic determination of water

    DOEpatents

    Fortier, N.E.; Fritz, J.S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present. 1 fig.

  4. Liquid chromatographic determination of water

    DOEpatents

    Fortier, Nancy E.; Fritz, James S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present.

  5. Calibration effects on orbit determination

    NASA Technical Reports Server (NTRS)

    Madrid, G. A.; Winn, F. B.; Zielenbach, J. W.; Yip, K. B.

    1974-01-01

    The effects of charged particle and tropospheric calibrations on the orbit determination (OD) process are analyzed. The calibration process consisted of correcting the Doppler observables for the media effects. Calibrated and uncalibrated Doppler data sets were used to obtain OD results for past missions as well as Mariner Mars 1971. Comparisons of these Doppler reductions show the significance of the calibrations. For the MM'71 mission, the media calibrations proved themselves effective in diminishing the overall B-plane error and reducing the Doppler residual signatures.

  6. Determinants of internet poker adoption.

    PubMed

    Philander, Kahlil S; Abarbanel, B Lillian

    2014-09-01

    In nearly all jurisdictions, adoption of a new form of gambling has been a controversial and contentious subject. Online gambling has been no different, though there are many aspects that affect online gambling that do not appear in the brick and mortar environment. This study seeks to identify whether demographic, economic, political, technological, and/or sociological determinants contribute to online poker gambling adoption. A theoretical discussion of these categories' importance to online poker is provided and exploratory empirical analysis is used to examine their potential validity. The analysis revealed support for all of the proposed categories of variables thought to be predictive of online gambling legality. PMID:23661279

  7. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  8. Crystal face temperature determination means

    DOEpatents

    Nason, D.O.; Burger, A.

    1994-11-22

    An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.

  9. Genetic modification and genetic determinism

    PubMed Central

    Resnik, David B; Vorhaus, Daniel B

    2006-01-01

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

  10. Age determination for Ultracool Dwarfs .

    NASA Astrophysics Data System (ADS)

    Faherty, Jacqueline K.

    Brown dwarfs are notoriously difficult to age date as they lack stable hydrogen burning hence main-sequence star age-dating techniques are inapplicable for their masses. However precise and accurate ages for individual sources are required to determine masses and disentangle how secondary parameters such as differing metallicity, cloud structure and gravity impact observables. In this contribution, I review age-dating techniques for brown dwarfs as well as ``piggy-back" techniques that rely on co-moving, higher mass, main-sequence stars for which Gaia may substantially increase the sample.

  11. SOP - Determination of Requirement Density

    SciTech Connect

    Reynolds, John G.; Martz, Jr., Harry E.

    2010-10-26

    The purpose of this Standard Operating Procedure (SOP) is to give guidelines on how to determine the density of a sample that will be used as the requirement density. This will be the requirement density of record for the specimens examined by Micro CT and EDS measurements. This density will then be set as the formulation requirement for radiography measurements. This SOP is referred to in TP 48— Preparation of Hydrogen Peroxide/Icing Sugar Specimens for X-ray Measurements by J. G. Reynolds and H. E. Martz.

  12. Crystal structure determination of Efavirenz

    NASA Astrophysics Data System (ADS)

    Popeneciu, Horea; Tripon, Carmen; Borodi, Gheorghe; Pop, Mihaela Maria; Dumitru, Ristoiu

    2015-12-01

    Needle-shaped single crystals of the title compound, C14H9ClF3NO2, were obtained from a co-crystallization experiment of Efavirenz with maleic acid in a (1:1) ratio, using methanol as solvent. Crystal structure determination at room temperature revealed a significant anisotropy of the lattice expansion compared to the previously reported low-temperature structure. In both low- and room temperature structures the cyclopropylethynyl fragment in one of the asymmetric unit molecules is disordered. While at low-temperature only one C atom exhibits positional disorder, at room temperature the disorder is present for two C atoms of the cyclopropane ring.

  13. Structure determination of enterovirus 71

    SciTech Connect

    Plevka, Pavel; Perera, Rushika; Cardosa, Jane; Kuhn, Richard J.; Rossmann, Michael G.

    2013-02-20

    Enterovirus 71 is a picornavirus that causes hand, foot and mouth disease but may induce fatal neurological illness in infants and young children. Enterovirus 71 crystallized in a body-centered orthorhombic space group with two particles in general orientations in the crystallographic asymmetric unit. Determination of the particle orientations required that the locked rotation function excluded the twofold symmetry axes from the set of icosahedral symmetry operators. This avoided the occurrence of misleading high rotation-function values produced by the alignment of icosahedral and crystallographic twofold axes. Once the orientations and positions of the particles had been established, the structure was solved by molecular replacement and phase extension.

  14. COBE ground segment attitude determination

    NASA Technical Reports Server (NTRS)

    Kumar, V. K.; Freedman, I.; Wright, E. L.; Patt, F. S.

    1991-01-01

    The Cosmic Background Explorer (COBE) spacecraft was launched in November 1989 by NASA to survey the sky for primordial radiation left from the Big Bang explosion. The success of the mission requires an accurate determination of the spacecraft attitude. While the accuracy of the attitude obtained from the attitude sensors is adequate for two of the experiments, the higher accuracy required by the Diffuse Infrared Background Experiment (DIRBE) is obtained by using the DIRBE instrument as a special type of star sensor. Presented here is an overview of the attitude processing algorithms used at the Cosmology Data Analysis Center (CDAC) and the results obtained from the flight data.

  15. Kaguya Orbit Determination from JPL

    NASA Technical Reports Server (NTRS)

    Haw, Robert J.; Mottinger, N. A.; Graat, E. J.; Jefferson, D. C.; Park, R.; Menom, P.; Higa, E.

    2008-01-01

    Selene (re-named 'Kaguya' after launch) is an unmanned mission to the Moon navigated, in part, by JPL personnel. Launched by an H-IIA rocket on September 14, 2007 from Tanegashima Space Center, Kaguya entered a high, Earth-centered phasing orbit with apogee near the radius of the Moon's orbit. After 19 days and two orbits of Earth, Kaguya entered lunar orbit. Over the next 2 weeks the spacecraft decreased its apolune altitude until reaching a circular, 100 kilometer altitude orbit. This paper describes NASA/JPL's participation in the JAXA/Kaguya mission during that 5 week period, wherein JPL provided tracking data and orbit determination support for Kaguya.

  16. Determination of Silicon in Hydrazine

    NASA Technical Reports Server (NTRS)

    McClure, Mark B.; Mast, Dion; Greene, Ben; Maes, Miguel J.

    2006-01-01

    Inductively coupled plasma-mass spectrometry (ICP-MS) is a highly sensitive technique sometimes used for the trace determination of silicon at a mass-to-charge (m/z) ratio of 28, the most abundant natural isotope of silicon. Unfortunately, ICP-MS is unable to differentiate between other sources of m/z 28 and false positive results for silicon will result when other sources of m/z 28 are present. Nitrogen was a major source of m/z 28 and contributes to the m/z 28 signal when hydrazine sample or nitric acid preservative is introduced into the plasma. Accordingly, this work was performed to develop a sample preparation step coupled with an ICP-MS analysis that minimized non-silicon sources of m/z 28. In the preparatory step of this method, the hydrazine sample was first decomposed predominately to nitrogen gas and water with copper-catalyzed hydrogen peroxide. In the analysis step, ICP-MS was used without nitric acid preservative in samples or standards. Glass, a potential source of silicon contamination, was also avoided where possible. The method was sensitive, accurate, and reliable for the determination of silicon in monopropellant grade hydrazine (MPH) in AF-E-332 elastomer leaching tests. Results for silicon in MPH were comparable to those reported in the literature for other studies.

  17. 'Columbus's Method of Determining Longitude'

    NASA Astrophysics Data System (ADS)

    Pickering, Keith A.

    I am pleased to see that, in light of my critical evaluation, Arne B. Molander has reevaluated a number of points in his analysis, and has revised his proposals of Columbus's alleged use of the Moon for determining his longitude. However, it is disappointing that these latest proposals again do not seem to have been thoroughly considered.Since it is clear that Columbus's East which usually can be done whether or not the conjunction itself is visible. However, it is entirely unclear how such an observation can be converted into a longitude. Reading attentively, we can glean a few details of this process: only a single observation is required, since some positions are computed within a few hours of the purported observation; and Columbus apparently used the Ephemerides of Johann Miiller, since errors in that ephemeris are alleged to have caused errors in the computed longitude. In his 1992 paper, Mr Molander asserted that timing of the conjunction is not required by this method, because Columbus somehow utilizes the Moon's daily topocentric motion. But how this datum is utilized, and in fact all details of the longitude determination itself, are entirely obscure.

  18. Determination of a mutational spectrum

    DOEpatents

    Thilly, William G.; Keohavong, Phouthone

    1991-01-01

    A method of resolving (physically separating) mutant DNA from nonmutant DNA and a method of defining or establishing a mutational spectrum or profile of alterations present in nucleic acid sequences from a sample to be analyzed, such as a tissue or body fluid. The present method is based on the fact that it is possible, through the use of DGGE, to separate nucleic acid sequences which differ by only a single base change and on the ability to detect the separate mutant molecules. The present invention, in another aspect, relates to a method for determining a mutational spectrum in a DNA sequence of interest present in a population of cells. The method of the present invention is useful as a diagnostic or analytical tool in forensic science in assessing environmental and/or occupational exposures to potentially genetically toxic materials (also referred to as potential mutagens); in biotechnology, particularly in the study of the relationship between the amino acid sequence of enzymes and other biologically-active proteins or protein-containing substances and their respective functions; and in determining the effects of drugs, cosmetics and other chemicals for which toxicity data must be obtained.

  19. Emergent evolutionism, determinism and unpredictability.

    PubMed

    Sartenaer, Olivier

    2015-06-01

    The fact that there exist in nature thoroughly deterministic systems whose future behavior cannot be predicted, no matter how advanced or fined-tune our cognitive and technical abilities turn out to be, has been well established over the last decades or so, essentially in the light of two different theoretical frameworks, namely chaos theory and (some deterministic interpretation of) quantum mechanics. The prime objective of this paper is to show that there actually exists an alternative strategy to ground the divorce between determinism and predictability, a way that is older than-and conceptually independent from-chaos theory and quantum mechanics, and which has not received much attention in the recent philosophical literature about determinism. This forgotten strategy-embedded in the doctrine called "emergent evolutionism"-is nonetheless far from being a mere historical curiosity that should only draw the attention of philosophers out of their concern for comprehensiveness. It has been indeed recently revived in the works of respected scientists. PMID:26227232

  20. Determination of a mutational spectrum

    SciTech Connect

    Thilly, W.G.; Keohavong, P.

    1991-09-03

    A method is disclosed of resolving (physically separating) mutant DNA from nonmutant DNA. A method is also described of defining or establishing a mutational spectrum or profile of alterations present in nucleic acid sequences from a sample to be analyzed, such as a tissue or body fluid. The present method is based on the fact that it is possible, through the use of DGGE, to separate nucleic acid sequences which differ by only a single base change and on the ability to detect the separate mutant molecules. The present invention, in another aspect, relates to a method for determining a mutational spectrum in a DNA sequence of interest present in a population of cells. The method of the present invention is useful as a diagnostic or analytical tool in forensic science in assessing environmental and/or occupational exposures to potentially genetically toxic materials (also referred to as potential mutagens); in biotechnology, particularly in the study of the relationship between the amino acid sequence of enzymes and other biologically-active proteins or protein-containing substances and their respective functions; and in determining the effects of drugs, cosmetics and other chemicals for which toxicity data must be obtained. 3 figures.