WorldWideScience

Sample records for pu allowed solutions

  1. The radiolysis of solutions containing Pu(6)

    International Nuclear Information System (INIS)

    Rance, P.J.W.; Zilberman, B.Y.

    2000-01-01

    The reduction of Pu(VI) in nitric acid solutions containing uranium and various fission product elements as a result of both its inherent alpha radiation and also external gamma irradiation at dose rates similar to those experienced by dissolved fuel solutions has been investigated. The presence of the additional metals has been shown to eliminate the induction periods required prior to the reduction of Pu(VI) in nitric acid. G values for the auto-radiolytic reduction of Pu(VI) have been found to be between 0.6 and 1.1 for 3 g/1 Pu solutions containing between 0.12 and 9.2 % 238 Pu (balance 239 Pu). Uranium and palladium have been found to accelerate the reduction of Pu(VI) during gamma irradiation at dose rates of between 0.41 and 1.64 kGy/hour. (authors)

  2. The radiolysis of solutions containing Pu(6)

    Energy Technology Data Exchange (ETDEWEB)

    Rance, P.J.W. [BNFL British Nuclear Fuels, Sellafield, Seascale, Cumbria, Research and Technology (United Kingdom); Zilberman, B.Y. [V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2000-07-01

    The reduction of Pu(VI) in nitric acid solutions containing uranium and various fission product elements as a result of both its inherent alpha radiation and also external gamma irradiation at dose rates similar to those experienced by dissolved fuel solutions has been investigated. The presence of the additional metals has been shown to eliminate the induction periods required prior to the reduction of Pu(VI) in nitric acid. G values for the auto-radiolytic reduction of Pu(VI) have been found to be between 0.6 and 1.1 for 3 g/1 Pu solutions containing between 0.12 and 9.2 % {sup 238}Pu (balance {sup 239}Pu). Uranium and palladium have been found to accelerate the reduction of Pu(VI) during gamma irradiation at dose rates of between 0.41 and 1.64 kGy/hour. (authors)

  3. Direct spectrophotometric analysis of low level Pu (III) in Pu(IV) nitrate solution

    International Nuclear Information System (INIS)

    Mageswaran, P.; Suresh Kumar, K.; Kumar, T.; Gayen, J.K.; Shreekumar, B.; Dey, P.K.

    2010-01-01

    Among the various methods demonstrated for the conversion of plutonium nitrate to its oxide, the oxalate precipitation process either as Pu (III) or Pu (IV) oxalate gained wide acceptance. Since uranous nitrate is the most successful partitioning agent used in the PUREX process for the separation of Pu from the bulk amount of U, the Pu (III) oxalate precipitation of the purified nitrate solution will not give required decontamination from U. Hence Pu IV oxalate precipitation process is a better option to achieve the end user's specified PuO 2 product. Prior to the precipitation process, ensuring of the Pu (IV) oxidation state is essential. Hence monitoring of the level of Pu oxidation state either Pu (III) or Pu (IV) in the feed solution plays a significant role to establish complete conversion of Pu (III). The method in vogue to estimate Pu(lV) content is extractive radiometry using Theonyl Trifluoro Acetone (TTA). As the the method warrants a sample preparation with respect to acidity, a precise measurement of Pu (IV) without affecting the Pu(III) level in the feed sample is difficult. Present study is focused on the exploration of direct spectrophotometry using an optic fiber probe of path length of 40mm to monitor the low level of Pu(III) after removing the bulk Pu(lV) which interfere in the Pu(III) absorption spectrum, using TTA-TBP synergistic mixture without changing the sample acidity

  4. Solution species of 239Pu [V] in the environment

    International Nuclear Information System (INIS)

    Rai, D.; Serne, R.J.; Swanson, J.L.

    1978-01-01

    Information regarding the oxidation states of Pu in environmental samples is needed for estimating its migration through the geologic media. Thermodynamic data were used to develop stability fields for different Pu species. The data indicate that in the Eh-pH range of natural aqueous environments, the dominant species of Pu is likely to be Pu[V] in relatively oxidizing environments and Pu[III] in reducing environments. Because of the lack of methods of determining Pu[V] in environmental samples containing trace concentrations of Pu, Pu[V] has not been previously identified in these samples. Plutonium [VI] is generally assumed to be the dominant species in relatively oxidizing environments. However, a combination of solvent extraction and spectrophotometric techniques used in this study show that solutions (> 10 -5 4 M Pu) in equilibrium with 239 Pu[IV] hydroxide contain Pu[V], which is in agreement with the thermodynamic predictions. Although this method could not be used conclusively with the remaining solutions ( -5 4 M Pu) contacting 239 Pu[IV] hydroxide and 239 PuO 2 , the solvent extraction and Eh-pH results are similar for all the samples suggesting the strong possibility that all samples contain Pu[V]. Thus the possibility, ignored in the past, that Pu[V] may be the dominant species in relatively oxidizing environments should be considered

  5. Raman spectrometric determination of Pu(VI) and Pu(V) in nitric acid solutions

    International Nuclear Information System (INIS)

    Gantner, E.; Freudenberger, M.; Steinert, D.; Ache, H.J.

    1987-03-01

    The determination of Pu(VI) in nitric acid solutions by spontaneous Laser Raman Spectrometry (LRS) was investigated and a calibration curve was established using U(VI) as internal standard. In addition, the concentrations of Pu(VI) and Pu(V) as a function of time were measured by this method in Pu(VI) solutions of different acidity containing H 2 O 2 as the reducing agent. In solutions which are intensely coloured by the presence of Ru(NO) complexes Pu(VI) can also be determined by LRS using a Kr + laser as excitation source. In future experiments, the study of the Pu(IV)-interaction with Ru using LRS and spectrophotometry as analytical techniques is therefore intended. (orig.) [de

  6. Investigation of the oxidation states of Pu isotopes in a hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.H. [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, P. O. Box 105, Yuseong, Daejeon 305-353 (Korea, Republic of)], E-mail: mhlee@kaeri.re.kr; Kim, J.Y.; Kim, W.H.; Jung, E.C.; Jee, K.Y. [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, P. O. Box 105, Yuseong, Daejeon 305-353 (Korea, Republic of)

    2008-12-15

    The characteristics of the oxidation states of Pu in a hydrochloric acid solution were investigated and the results were applied to a separating of Pu isotopes from IAEA reference soils. The oxidation states of Pu(III) and Pu(IV) were prepared by adding hydroxylamine hydrochloride and sodium nitrite to a Pu stock solution, respectively. Also, the oxidation state of Pu(VI) was adjusted with concentrated HNO{sub 3} and HClO{sub 4}. The stability of the various oxidation states of plutonium in a HCl solution with elapsed time after preparation were found to be in the following order: Pu(III){approx}Pu(VI)>Pu(IV)>Pu(V). The chemical recoveries of Pu(IV) in a 9 M HCl solution with an anion exchange resin were similar to those of Pu(VI). This method for the determination of Pu isotopes with an anion exchange resin in a 9 M HCl medium was applied to IAEA reference soils where the activity concentrations of {sup 239,240}Pu and {sup 238}Pu in IAEA-375 and IAEA-326 were consistent with the reference values reported by the IAEA.

  7. Local structure of Th1-xMO2 solid solutions (M = U, Pu)

    International Nuclear Information System (INIS)

    Hubert, S.; Heisbourg, G.; Moisy, Ph.; Dacheux, N.; Purans, J.E.

    2004-01-01

    X-ray absorption spectroscopy of Th 1-x U x O 2 and Th 1-x Pu x O 2 solid solutions was carried out on the Th, U L 3 -edges, and Pu L 3 edge to study the local structure environment of actinide mixed oxides. Various compositions of Th 1-x M x O 2 solid solutions have been prepared through the coprecipitation of the mixed oxalates from chloride or nitrate solutions: x = 0.11, 0.24, 0.37, 0.53, 0.67, 0.81, 0.91 and 1 for Th 1-x U x O 2 , and x = 0.13, 0.32, 0.66 and 1 for Th 1-x Pu x O 2 . They were characterized using X- ray diffraction. XRD analysis allowed to confirm that the variation of the lattice parameters varies linearly with the composition between the end members, suggesting that the atomic volume was conserved regardless of the details of the local distortions of the lattice, following the Vegard's law. Extending X-ray absorption fine structure (EXAFS) provides a direct characterization of the local distortions present in solid solutions. We found that opposite to the lattice parameter obtained by XRD, the interatomic distances given by EXAFS do not follow completely to neither the Vegard's law nor the virtual crystal approximation (VCA). However, the average lattice parameter obtained from EXAFS data for the first and the second shells agrees well with the one calculated from XRD data. (authors)

  8. Behaviour of Pu-IV with various ion exchangers in solutions containing nitric acid and oxalates

    International Nuclear Information System (INIS)

    Walter, E.; Ali, S.A.

    1982-02-01

    The distribution of Pu-IV on the ion exchangers Dowex 50W-X8, Dowex 1-X8 und Dowex Chelating Resin Al-X8 in the presence of various concentrations of nitric acid and oxalate were investigated. The results indicate that nitric acid and oxalic acid influence each other during complexation of Pu-IV with oxalate ions solutions containing nitric acid it is not possible to neglect the formation of Pu-IV nitrate complexes. The complex Pu(IV) (C 2 O 4 ) 3 2 - only is formed in solutions containing low nitric acid and high oxalic acid concentrations. The separation of Pu-IV in Dowex Chelating Resin from nitric acid solution in the presence of higher oxalate concentrations is possible, provided that the nitric acid concentration is lower than 0.25 molar [fr

  9. 239, 240, 241Pu fingerprinting of plutonium in western US soils using ICPMS: solution and laser ablation measurements

    International Nuclear Information System (INIS)

    Cizdziel, James V.; Ketterer, Michael E.; Farmer, Dennis; Faller, Scott H.; Hodge, Vernon F.

    2008-01-01

    Sector field inductively coupled plasma mass spectrometry (SF-ICPMS) has been used with analysis of solution samples and laser ablation (LA) of electrodeposited alpha sources to characterize plutonium activities and atom ratios prevalent in the western USA. A large set of surface soils and attic dusts were previously collected from many locations in the states of Nevada, Utah, Arizona, and Colorado; specific samples were analyzed herein to characterize the relative contributions of stratospheric fallout vs. Nevada Test Site (NTS) plutonium. This study illustrates two different ICPMS-based analytical strategies that are successful in fingerprinting Pu in environmental soils and dusts. Two specific datasets have been generated: (1) soils are leached with HNO 3 -HCl, converted into electrodeposited alpha sources, counted by alpha spectrometry, then re-analyzed using laser ablation SF-ICPMS; (2) samples are completely dissolved by treatment with HNO 3 -HF-H 3 BO 3 , Pu fractions are prepared by extraction chromatography, and analyzed by SF-ICPMS. Optimal laser ablation and ICPMS conditions were determined for the re-analysis of archived alpha spectrometry ''planchette'' sources. The best ablation results were obtained using a large spot size (200 μm), a defocused beam, full repetition rate (20 Hz) and scan rate (200 μm s -1 ); LA-ICPMS data were collected with a rapid electrostatic sector scanning experiment. Less than 10% of the electroplated surface area is consumed in the LA-ICPMS analysis, which would allow for multiple re-analyses. Excellent agreement was found between 239+240 Pu activities determined by LA-ICPMS vs. activity results obtained by alpha spectrometry for the same samples ten years earlier. LA-ICPMS atom ratios for 240 Pu/ 239 Pu and 241 Pu/ 239 Pu range from 0.038-0.132 and 0.00034-0.00168, respectively, and plot along a two-component mixing line ( 241 Pu/ 239 Pu = 0.013 [ 240 Pu/ 239 Pu] - 0.0001; r 2 = 0.971) with NTS and global fallout end

  10. Thermal conductivities of (ZrxPu(1-x)/2Am(1-x)/2)N solid solutions

    International Nuclear Information System (INIS)

    Nishi, Tsuyoshi; Takano, Masahide; Akabori, Mitsuo; Arai, Yasuo

    2011-01-01

    The thermal conductivity of Zr-based transuranium (TRU) nitride solid solutions is important for designing subcritical cores in nitride-fueled ADS. Some results have been reported concerning the thermal conductivities of (Zr,Pu)N. However, there have been no experimental data on the thermal conductivities of Zr-based nitride solid solutions containing MA. In this study, the authors prepared sintered samples of (Zr x Pu (1-x)/2 Am (1-x)/2) N (x=0.0, 0.58, 0.80) solid solutions. The thermal diffusivity and heat capacity of (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions were measured using a laser flash method and drop calorimetry, respectively. Thermal conductivities were determined from the measured thermal diffusivities, heat capacities and bulk densities over a temperature range of 473 to 1473 K. The thermal conductivities of (Zr 0.58 Pu 0.21 Am 0.21 )N and (Zr 0.80 Pu 0.10 Am 0.10 )N solid solutions were found to be higher than that of (Pu 0.5 Am 0.5 )N due to the high thermal conductivity of ZrN as the principal component, although they were lower than that of ZrN due to the impurifying effect of the transuranium elements. Thus, the thermal conductivities of (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions increased with increasing ZrN concentration. Moreover, in order to help to promote the design study of nitride-fueled ADS, the thermal conductivity of the (Zr x Pu (1-x)/2 Am (1-x)/2) N solid solutions were fitted to an equation using the least squares method. (author)

  11. Determination of U and Pu in highly radioactive solutions. Application to the analysis of fuel reprocessing solutions

    International Nuclear Information System (INIS)

    Denis, Alphonse

    Various devices intended for the X-ray fluorescence analysis of U and Pu in radioactive solutions were developed in a hot cell: a device for sample deposition and preparation; a measurement unit. The problems investigated are described [fr

  12. Migration of 137Cs, 90Sr, 239,240Pu and 241Am in the chain soil-soil solution-plant. The soil-soil solution link

    International Nuclear Information System (INIS)

    Sokolik, G.A.; Ovsyannikova, S.V.; Kil'chitskaya, S.L.; Ehjsmont, E.A.; Zhukovich, N.V.; Kimlenko, I.M.; Duksina, V.V.; Rubinchik, S.Ya.

    1999-01-01

    The mobility of 137 Cs, 90 Sr, 239,240 Pu and 241 Am in the link soil-soil solution is analysed for different soil types on the basis of radionuclide distribution coefficients between solid and liquid soil phases. The distribution coefficients allow to differentiate soils in correlation with radionuclide migration rate from the solid phase to the soil solution. The reasons of different radionuclide mobility are considered

  13. Calculated k-effectives for light water reactor typical, U + Pu nitrate solution critical experiments

    International Nuclear Information System (INIS)

    Primm, R.T. III; Mincey, J.F.

    1982-01-01

    The Department of Energy's Consolidated Fuel Reprocessing Program has as a goal the design of nuclear fuel reprocessing equipment. In order to validate computer codes used for criticality analyses in the design of such equipment, k-effectives have been calculated for several U + Pu nitrate solution critical experiments. As of January 1981, descriptions of 45 unpoisoned, U + Pu solution experiments were available in the open literature. Twelve of these experiments were performed with solutions which have physical characteristics typical of dissolved, light water reactor fuel. This paper contains a discussion of these twelve experiments, a review of the calculational procedure used to determine k-effectives, and the results of the calculations

  14. Improvement of INVS Measurement Uncertainty for Pu and U-Pu Nitrate Solution

    Energy Technology Data Exchange (ETDEWEB)

    Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Marlow, Johnna Boulds [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Makino, Risa [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Nakamura, Hironbu [Japan Atomic Energy Agency (JAEA), Tokai (Japan)

    2017-04-27

    In the Tokai Reprocessing Plant (TRP) and the Plutonium Conversion Development Facility (PCDF), a large amount of plutonium nitrate solution which is recovered from light water reactor (LWR) and advanced thermal reactor (ATR), FUGEN are being stored. Since the solution is designated as a direct use material, the periodical inventory verification and flow verification are being conducted by Japan Safeguard Government Office (JSGO) and International Atomic Agency (IAEA).

  15. The disproportionation of Pu4+ in nitric acid solutions

    International Nuclear Information System (INIS)

    Toth, L.M.; Bell, J.T.; Friedman, H.A.

    1990-01-01

    The Pu 4+ disproportionation equilibrium in nitric acid has been examined at ≤25deg C to extend our understanding and predictive ability with regard to species distribution under these conditions. Vis/UV absorption spectrophotometry has been used in a conventional manner to determine the concentrations of the various plutonium species. Values for the overall equilibrium quotient at 5, 15, and 25deg C were determined to be 0.098, 3.46, and 58.8, respectively, at zero ionic strength. From these values, the enthalpy of the reaction was found to be +52.7 kcal (220 kJ)/mol. The excellent reproducibility of the equilibrium quotients, even while parameters such as acid, nitrate ion and plutonium concentrations were changed, lend confidence to future predictive calculations regarding this reaction. (orig.)

  16. Redox reactions of Pu(IV) and Pu(III) in the presence of acetohydroxamic acid in HNO(3) solutions.

    Science.gov (United States)

    Tkac, Peter; Precek, Martin; Paulenova, Alena

    2009-12-21

    The reduction of Pu(IV) in the presence of acetohydroxamic acid (HAHA) was monitored by vis-NIR spectroscopy. All experiments were performed under low HAHA/Pu(IV) ratios, where only the Pu(IV)-monoacetohydroxamate complex and Pu uncomplexed with HAHA were present in relevant concentrations. Time dependent concentrations of all absorbing species were resolved using molar extinction coefficients for Pu(IV), Pu(III), and the Pu(AHA)(3+) complex by deconvolution of spectra. From fitting of the experimental data by rate equations integrated by a numeric method three reactions were proposed to describe a mechanism responsible for the reduction and oxidation of plutonium in the presence of HAHA and HNO(3). Decomposition of Pu(AHA)(3+) follows a second order reaction mechanism with respect to its own concentration and leads to the formation of Pu(III). At low HAHA concentrations, a two-electron reduction of uncomplexed Pu(IV) with HAHA also occurs. Formed Pu(III) is unstable and slowly reoxidizes back to Pu(IV), which, at the point when all HAHA is decomposed, can be catalyzed by the presence of nitrous acid.

  17. Calorimetric measurements on plutonium rich (U,Pu)O2 solid solutions

    International Nuclear Information System (INIS)

    Kandan, R.; Babu, R.; Nagarajan, K.; Vasudeva Rao, P.R.

    2008-01-01

    Enthalpy increments of U (1-y) Pu y O 2 solid solutions with y = 0.45, 0.55 and 0.65 were measured using a high-temperature differential calorimeter by employing the method of inverse drop calorimetry in the temperature range 956-1803 K. From the fit equations for the enthalpy increments, other thermodynamic functions such as heat capacity, entropy and Gibbs energy function have been computed in the temperature range 298-1800 K. The results are presented and compared with the data available in the literature. The results indicate that the enthalpies of U (1-y) Pu y O 2 solid solutions with y = 0.45, 0.55 and 0.65 obey the Neumann-Kopp's molar additivity rule

  18. Evaluations of photo-solution chemical behaviors of Pu and Np

    International Nuclear Information System (INIS)

    Wada, Yukio; Morimoto, Kyouichi; Tomiyasu, Hiroshi.

    1995-01-01

    A photochemical method of removing Np from a mixture of nitric acid solutions of Pu and Np has been studied in connection with the Purex reprocessing procedure. From these experiments, we confirmed the potential of the photochemical valency adjustment technology as an advanced reprocessing one. Furthermore, the applicability of the installation for the process and the mechanism of photochemical reactions from the standpoint of thermodynamic considerations were discussed. (author)

  19. Reactivity of the uranium (U(IV)/U(VI)) and the plutonium (Pu(III)/Pu(IV)) in nitric aqueous solution under ultrasound

    International Nuclear Information System (INIS)

    Venault, L.

    1998-01-01

    To minimize the volumes of solid waste and industrial effluents generated at the end of cycle, particularly in the spent nuclear fuel reprocessing industry, research is currently under way on so-called innovative processes, designed to induce chemical reactions without adding reagent to the media. Among these processes, the use of ultrasound can prove advantageous, and the purpose of this study is to assess accurately the potential for its application. In the present context, this work shows that the transmission of an ultrasonic wave in aqueous nitric acid solution leads to: the accumulation of nitrous acid in solution, until a steady-sate concentration is reached; the removal of nitrogen monoxide and nitrogen dioxide in the gas stream. The initial kinetics of the formation of HNO 2 in solution was quantified as a function of the nitric acid concentration and the ultrasound intensity. It was also shown than an excess of nitrous acid in nitric solution decomposes under the effect of ultrasound. It is also possible to accumulate hydrogen peroxide in solution during the ultrasonic irradiation of aqueous nitric acid solutions in the presence of a chemical species N 2 H 5 + , NH 2 SO 3 H...) which reacts rapidly with HNO 2 , preventing the reduction of H 2 O 2 by HNO 2 . The mechanisms of HNO 2 formation and decomposition, and the mechanism of H 2 O 2 formation during the ultrasonic irradiation of aqueous nitric acid solutions, are presented. Control of H 2 O 2 or HNO 2 in a nitric acid medium under the effect of an ultrasonic wave can be exploited to control redox reactions of uranium and plutonium ions, particularly with respect to the oxidation of U and Pu (U(IV)→ U(IV) or Pu(III) → Pu(IV)) and the reduction of Pu (Pu(IV)→ Pu(III). The redox behavior of uranium and plutonium ions in aqueous nitric solution subject to an ultrasonic flux is interpreted in term of effects induced on the reaction medium, and reveals the potential for using ultrasound to cause

  20. Reactivity prediction of uniform PuO2-UO2 fuelled lattices and Pu(NO3)4 solutions in light water

    International Nuclear Information System (INIS)

    Mohankrishnan, P.; Huria, H.C.

    A theoretical analysis of the reactivities of the experimentally measured uniform light water moderated and reflected PuO 2 in UO 2 lattices and Pu(NO 3 ) 4 solutions is presented here. The mixed oxide single rod lattices are homogenised by the use of multigroup integral transport theory and diffusion theory is used for the cylindrical core calculations. The cross-sections are derived from the WTIS library. The homogeneous spherical Pu(NO 3 ) 4 solutions are analysed by discrete ordinate transport theory. Due to the small size of these criticals, it is necessary that one dimensional core calculations also be performed with a cross-section energy group structure which can represent neutron slowing down and thermalisation at the core reflector interface accurately. Due to the absence of such core calculation in the BNWL analyses of the mixed oxide lattices, the agreement of or predictions for these lattices with measurement is considered to be more satisfactory. These reactivity predictions are found to agree generally within +- 0.6% of measurements for the mixed oxide lattices and within 1% for the solution system. (author)

  1. Validation of MCNP6.1 for Criticality Safety of Pu-Metal, -Solution, and -Oxide Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kiedrowski, Brian C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kahler, III, Albert C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kersting, Alyssa R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parsons, Donald K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Walker, Jessie L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-05-13

    Guidance is offered to the Los Alamos National Laboratory Nuclear Criticality Safety division towards developing an Upper Subcritical Limit (USL) for MCNP6.1 calculations with ENDF/B-VII.1 nuclear data for three classes of problems: Pu-metal, -solution, and -oxide systems. A benchmark suite containing 1,086 benchmarks is prepared, and a sensitivity/uncertainty (S/U) method with a generalized linear least squares (GLLS) data adjustment is used to reject outliers, bringing the total to 959 usable benchmarks. For each class of problem, S/U methods are used to select relevant experimental benchmarks, and the calculational margin is computed using extreme value theory. A portion of the margin of sub criticality is defined considering both a detection limit for errors in codes and data and uncertainty/variability in the nuclear data library. The latter employs S/U methods with a GLLS data adjustment to find representative nuclear data covariances constrained by integral experiments, which are then used to compute uncertainties in keff from nuclear data. The USLs for the classes of problems are as follows: Pu metal, 0.980; Pu solutions, 0.973; dry Pu oxides, 0.978; dilute Pu oxide-water mixes, 0.970; and intermediate-spectrum Pu oxide-water mixes, 0.953.

  2. Studies on Benzo-DODA encapsulated polymeric beads for separation of Pu from acidic solution

    International Nuclear Information System (INIS)

    Singh, K.K.; Panja, S.; Kumar, M.; Ruhela, R.; Tripathi, S.C.; Singh, A.K.; Hubli, R.C.; Bajaj, P.N.

    2014-01-01

    High level liquid waste (HLLW) generated during the reprocessing of spent fuel contains a few mg of Pu per litre of waste volume. Therefore, there is a need for selective separation of Pu from above solution as well as other such acidic waste streams. The widely used technology for separation and recovery of metal ions from radioactive wastes is liquid-liquid extraction.Though, such technologies play major role in all the bulk separation processes, they have marked limitations involving the losses of extractant in aqueous phase, third phase problems at higher metal loading, etc. These limitations have necessitated the exploration of advance, more efficient and technically feasible alternatives. In this regard it is thought that solid-liquid based Extractant Encapsulated Polymeric Beads (EEPBs) may solve some of the problems. Benzodioxodiamide (BenzoDODA) is a recently reported extractant for the separation of plutonium from radioactive waste, containing nitric acid. BenzoDODA extractant encapsulated polymeric beads were prepared by phase inversion technique and found to be quite stable as no significant structural deformation or leaching out of the extractant was observed in 4.0 M HNO 3 solution, up to studied equilibration time of 8 days. These beads have been characterized by FT-IR, TGA and SEM techniques to gain insight into their structure and morphology. Morphology and porosity of the beads, as studied by the SEM analysis, indicate that the surface of the beads is quite rough, and has enough porosity. Thermo gravimetric analysis of the synthesized composite beads shows a weight loss of ∼74% during the heating from room temperature to 120℃, due to the loss of water present in the swollen beads. Such high water content also confirms that the beads have enough porosity for efficient exchange of metal ions.The synthesized beads were evaluated, for their ability to absorb Pu from acidic solution. The kinetics measurement showed that about 45 min of

  3. Reactivity of the uranium (U(IV)/U(VI)) and the plutonium (Pu(III)/Pu(IV)) in nitric aqueous solution under ultrasound; De l'influence des ultrasons sur la reactivite de l'uranium (U(IV)/U(VI)) et du plutonium (PU(III)/PU(IV)) en solution aqueuse nitrique

    Energy Technology Data Exchange (ETDEWEB)

    Venault, L

    1998-07-01

    To minimize the volumes of solid waste and industrial effluents generated at the end of cycle, particularly in the spent nuclear fuel reprocessing industry, research is currently under way on so-called innovative processes, designed to induce chemical reactions without adding reagent to the media. Among these processes, the use of ultrasound can prove advantageous, and the purpose of this study is to assess accurately the potential for its application. In the present context, this work shows that the transmission of an ultrasonic wave in aqueous nitric acid solution leads to: the accumulation of nitrous acid in solution, until a steady-sate concentration is reached; the removal of nitrogen monoxide and nitrogen dioxide in the gas stream. The initial kinetics of the formation of HNO{sub 2} in solution was quantified as a function of the nitric acid concentration and the ultrasound intensity. It was also shown than an excess of nitrous acid in nitric solution decomposes under the effect of ultrasound. It is also possible to accumulate hydrogen peroxide in solution during the ultrasonic irradiation of aqueous nitric acid solutions in the presence of a chemical species (N{sub 2}H{sub 5}{sup +}, NH{sub 2}SO{sub 3}H...) which reacts rapidly with HNO{sub 2}, preventing the reduction of H{sub 2}O{sub 2} by HNO{sub 2}. The mechanisms of HNO{sub 2} formation and decomposition, and the mechanism of H{sub 2}O{sub 2} formation during the ultrasonic irradiation of aqueous nitric acid solutions, are presented. Control of H{sub 2}O{sub 2} or HNO{sub 2} in a nitric acid medium under the effect of an ultrasonic wave can be exploited to control redox reactions of uranium and plutonium ions, particularly with respect to the oxidation of U and Pu (U(IV){yields} U(IV) or Pu(III) {yields} Pu(IV)) and the reduction of Pu (Pu(IV){yields} Pu(III). The redox behavior of uranium and plutonium ions in aqueous nitric solution subject to an ultrasonic flux is interpreted in term of effects

  4. The interaction of Np(V), Pu(VI) and Tc(VII) with metal in alkaline solutions

    International Nuclear Information System (INIS)

    Silin, V.I.; Kareta, A.V.

    1998-01-01

    The interaction of Np(V), Pu(VI) and Tc(VII) with metal reductants Zn, Cr, Sn and their alloys was investigated in 0.5-4 mol l -1 NaOH solutions in static and dynamic conditions (by filtration of solutions through the column filled with grains of metal). In this paper, it was found that the reduction and succeeding precipitation hydroxides of these elements, on the surface of metal grains from 0.5 to 4 mol l -1 NaOH solutions, gives a decontamination factor (DF) from 1.1 to 67. The best result was achieved for Pu (DF=67) on Cr grains after 2.5 h contact at 60 C with 0.5 mol l -1 NaOH solution containing Pu(VI). Increasing the NaOH concentration, and the addition of chromate ions and complex-forming agents to alkaline solution results in a decrease of the decontamination factor (DF). A better result for Np sorption from 1 mol l -1 NaOH solutions was achieved after longer contact, than for Pu, with Cr and Zn grains. The maximum DF=8.9 was achieved for Tc on a column with Zn grains after filtration with a 3.5 mol l -1 NaOH solution containing Tc(VII). Washing out of Np and Pu, sorbed on the Cr grain surfaces, was achieved using an acid solution (1 mol l -1 HNO 3 ). The technetium was desorbed from metal surface by 10% H 2 O 2 solution. (orig.)

  5. Adsorption and recovery of lead(II) from aqueous solutions by immobilized Pseudomonas Aeruginosa PU21 beads

    International Nuclear Information System (INIS)

    Lin, C.-C.; Lai, Y.-T.

    2006-01-01

    In this study, immobilized Pseudomonas aeruginosa PU21 beads were used as an adsorbent for lead(II). Different weight percentages of chitosan were added to polyethylene glycol (PEG, 0.5 wt.% in aqueous solution) and alginate (18 wt.% in aqueous solution), and then blended or cross-linked using different concentrations of epichlorohydrin (ECH) to prepare beads of different sizes and increased mechanical strength. Before blending or cross-linking, different weight percentages of P. aeruginosa PU21 were added to increase lead(II) adsorption. Subsequently the optimized bead composition (concentration of ECH, percentages of chitosan and P. aeruginosa PU21) and the optimum adsorption conditions (agitation rate and pH in the aqueous solution) were ascertained. Finally, the optimized beads adsorbing lead(II) were regenerated by 0.1 M aqueous HCl solutions and the most effective desorption agitation rate was ascertained. The results indicate that the reuse of immobilized P. aeruginosa PU21 beads was feasible. In addition, the equilibrium adsorption, kinetics, changes in the thermodynamic properties of adsorption of lead(II) on optimized beads were also investigated

  6. Adjustment of valence state of Pu and Np in nitric solution containing N,N-dimethylhydroxylamine and monomethylhydrazine by electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Ye, G.A.; Cong, H.F. [China Institute of Atomic Energy, Beijing (China)] [and others

    2012-07-01

    A study of the electrochemical behaviors of N,N-dimethylhydroxylamine (DMHAN) and monomethyl hydrazine (MMH) in nitric acid solution on Pt electrodes were carried out by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) methods. The diffusion coefficients of DMHAN and MMH were obtained by CV. The values are found to be 0.53 x 10{sup -6}6 cm{sup 2}/s D{sub (DMHAN)} and 0.88 x 10{sup -5} cm{sup 2}/s D{sub (MMH)}. The equilibrium potentials (+0.47 V vs. SCE for DMHAN and +0.31 V vs. SCE for MMH) were also measured using Tafel curves. Various valence states of Pu and Np in HNO{sub 3} solution containing DMHAN and MMH in the electrolytic process were investigated by an electrolytic cell using a platinum as the anode and a titanium plate as the cathode. In this procedure, MMH was first electro-oxidized on the Pt anode and Np(V) was reduced to Np(IV) on the Ti cathode. After MMH was entirely consumed, the accumulation of HNO{sub 2} (due to the electrochemical reduction of nitric acid on the Ti cathode) caused a significantly fast catalytic reaction of DMHAN with HNO{sub 3} to form HNO{sub 2}. HNO{sub 2} can oxidize Pu(III) to Pu(IV) quickly. As a result, both oxidation states of Pu and Np were found to be tetravalent in the post-electrolysis solution. A convenient method to keep the post-electrolysis solution at 70 C was used to adjust the oxidation state of Np in it's pentavalent state while retaining the tetravalent state of Pu. This study developed an electrolytic process for the preparation of 2AF feed (the feed of Pu purification cycle) in APOR (Advanced Purex Process Based on Organic Reductants) process by electrochemically oxidizing Pu(III) and selectively adjusting the valence state of neptunium to either Np(IV) or Np(V). (orig.)

  7. Kinetics and thermodynamics of the dissolution of Th1-xMxO2 solid solutions (M = U, Pu)

    International Nuclear Information System (INIS)

    Hubert, S.; Heisbourg, G.; Dacheux, N.; Moisy, Ph.; Purans, J.

    2004-01-01

    Kinetics of the dissolution of Th 1-x M x O 2 (M = U, Pu) solid solutions was investigated as a function of several chemical parameters such as pH, substitution ratio, temperature, ionic strength, and electrolyte. Several compositions of Th 1-x U x O 2 and Th 1-x Pu x O 2 were synthesized and characterized before and after leaching by using several methods such as XRD, EXAFS, BET, PIXE, SEM, and XPS. Leaching tests were performed in nitric, hydrochloric or sulfuric media and groundwater. The normalized dissolution rates were evaluated for Th 1-x U x O 2 , and Th 0.88 Pu 0.12 O 2 leading to the determination of the partial order related to the proton concentration, n, and to the corresponding normalized dissolution rate constant at pH = 0, k'T. While for Th enriched solids, the solid solutions Th 1-x U x O 2 have the same dissolution behaviour than ThO 2 with a partial order n ∼ 0.3, in the case of uranium enriched solids, Th 1-x U x O 2 has the same dissolution behaviour than UO 2 with a partial order of n = 1, indicating that uranium oxidation rate becomes the limiting step of the dissolution process. The stoichiometry of the release of both actinides (U or Pu, Th) was verified until the precipitation of thorium occurred in the leachate for pH > 2, while uranium was released in the solution as an uranyl form. For uranium enriched solid solutions, thermodynamic equilibrium was reached after 100 days, and solubility constant of secondary phase was determined. In the case of Th 1-x Pu x O 2 , the dissolution behaviour is similar to that of ThO 2 , but only kinetic aspect of the dissolution can be studied. From the analysis of XPS and EXAFS data on leached and un-leached Th 1-x U x O 2 samples, the dissolution mechanism of solid solutions was explained and will be discussed. The role of the electrolytes on the dissolution of the solid solutions is discussed. Kinetics parameters of dissolution are also given in groundwater and in neutral media

  8. Debunking the myths: Natural gas and SO2 allowance solutions

    International Nuclear Information System (INIS)

    Roberts, G.D. Jr.

    1993-01-01

    During the decade of the 1990's and beyond, natural gas is expected to be the fuel of choice for a significant portion of new generation capacity. Natural gas already enjoys a greater than 50% market share as a fuel source in the non-regulated cogeneration and Independent Power Producer market. With the new administration in Washington, increased environmental focus will likely increase the attractiveness of natural gas based capacity expansions. While these various issues may appear to contribute to making this decade, the decade for natural gas, there are a number of challenges that must be met if the natural gas and power generation industries are going to satisfy the ever increasing needs of the marketplace. These challenges include: (1) myths of natural gas supply availability, (2) transportation and operational coordination issues, (3) uncertainty of price and reliability, and (4) natural gas for NO x and SO 2 compliance. The author believes that these challenges are actively being met and that there are existing solutions already being offered and incorporated into contracts by natural gas suppliers. The focus of this paper is how electric utilities need to become comfortable with the new natural gas industry and how services can be structured to meet these challenges of serving the electric market requirements

  9. Rate of Pu(IV) polymer formation in nitric acid solutions. A parametric study

    Energy Technology Data Exchange (ETDEWEB)

    Toth, L.M.; Osborne, M.M.

    1984-07-01

    The kinetics of Pu(IV) polymer formation has been examined with the intent of developing a simple mathematical equation that would predict the appearance of polymer. The fundamental polymerization rate has been found to be dependent on [Pu(IV)]{sup 1} {sup 2} and [HNO{sub 3}]{sup -6}. The activation energy for polymer formation is real temperature dependent, varying from 66.9 kJ/mol (16 kcal/mol) at 25{sup 0}C to 150.5 kJ/mol (36 kcal/mol) at 105{sup 0}C. These relationships have guided the developement of an empirical model that gives time to form 2% polymer in hours, t = [Pu/sub T/]/sup a/[HNO{sub 3}]/sup b/ Ae/sup c/T/, where a = -1.6, b = 4.6, c = 12.300 K, and A = 7.66 x 10{sup -16} h M{sup -3}; [Pu/sub T/] is the total plutonium concentration, mol/L; and [HNO{sub 3}] is the makeup nitric acid concentration, mol/L. 11 references, 26 figures, 1 table.

  10. User's guide for the portable microprocessor equipment: 'KfK K-edge densitometer' for quantitative determination of Th, U, Np, Pu, Am in solutions

    International Nuclear Information System (INIS)

    Michel-Piper, I.; Matussek, P.

    1985-06-01

    This report describes the hardware and software features, and the use of the microprocessor-controlled multichannel analyzer system SILENA + IRIS. The self-contained portable system, which permits independent accumulation and evaluation of spectral data from the KfK K-edge densitometer, provides one of the possible means for the authentication of resident instruments by safeguards inspectors. The 'K-Edge' program, written in PL/M language for compatibility with the system's firmware, allows fully automated assays of heavy element concentrations in solutions by means of X-ray absorption edge spectrometry. It is primarily intended for highly accurate determinations of the U and Pu content in process- and product solutions of a reprocessing plant. (orig.)

  11. Effects of aging on PuO{sub 2} . xH{sub 2}O particle size in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H. [Pacific Northwest National Laboratory, Richland, WA (United States)

    2013-08-01

    Between 1944 and 1989, 54.5 metric tons of the United States' weapons-grade plutonium and an additional 12.9 metric tons of fuels-grade plutonium were produced in and separated from irradiated uranium metal fuel at the Hanford Site. Acidic high-activity wastes containing around 600 kg of plutonium were made alkaline and discharged to underground storage tanks from separations, isolation, and recycle processes to yield average plutonium concentration of about 0.003 g/L (or {proportional_to} 0.0002 wt. %) in the {proportional_to} 200 million liter tank waste volume. The plutonium is largely associated with low-solubility metal hydroxide/oxide sludges where its low concentration and intimate mixture with neutron-absorbing elements (e.g., iron) are credited in nuclear criticality safety. However, concerns have been expressed that plutonium, in the form of hydrated plutonium oxide, PuO{sub 2} . xH{sub 2}O, could undergo sufficient crystal growth through dissolution and reprecipitation in the alkaline tank waste to potentially become separable from neutron absorbing constituents by settling or sedimentation. Thermodynamic considerations and laboratory studies of systems chemically analogous to tank waste show that the plutonium, precipitated in the alkaline tank waste by neutralization from acid solution, probably entered as 2-5-nm PuO{sub 2} . xH{sub 2}O, crystallite particles that, because of the low concentration of the neutral Pu(IV) dissolved species and opposition from radiolytic processes, grow from that point at exceedingly slow rates. (orig.)

  12. Studies on the effect of Pu and fission products on extraction selectivity of polymeric composite of ammonium phosphomolybdate towards 137Cs from nitric acid solutions

    International Nuclear Information System (INIS)

    Tripathi, S.C.; Pathak, S.K.; Jambunathan, U.; Dakshinamoorthy, A.; Kumar, Manmohan; Bajaj, P.N.

    2007-01-01

    Ultrafine particle size of ammonium phosphomolybdate (AMP) though selective sorbent for Cs form acidic solution, has limitation due to its incompatibility with column operation under practical conditions. A polymeric composite containing ammonium Phospho molybdate(AMP) developed indigenously in granular form, has shown encouraging results for Cs uptake from acidic solutions. Present investigation describes experimental observations carried out to find out the effect of presence of Pu and fission products on the 137 Cs uptake. The polymeric material shown some tendency for sorption of Pu which is found to decrease with increasing acidity. It has great selectivity with respect to other fission products like cerium, zirconium, and ruthenium. (author)

  13. The chemistry of Pu in concentrated aqueous NaCl solution: Effects of alpha self-radiolysis and the interaction between hypochlorite and dioxoplutonium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Pashalidis, I. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany)); Kim, J.I. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany) Inst. fuer Nukleare Entsorgungstechnik, Kernforschungszentrum Karlsruhe (Germany)); Lierse, C. (Inst. fuer Radiochemie, TU Muenchen, Garching (Germany)); Sullivan, J.C. (Chemistry Div., Argonne National Lab., IL (United States))

    1993-01-01

    The reactions between dioxoplutonium(VI) and hypochlorite in aqueous solution produce the species PuO[sub 2](OH)(ClO) and PuO[sub 2](ClO)[sub 2]. The results of spectrophotometric observations are presented and the data used to calculate values of log K=14.0 at pH=6.7 and 14.5 at pH=8.4 for the former complex and a value of 10.3 for the latter. The possible participation of 6d orbitals in these reactions is noted. (orig.)

  14. Determination of the activity concentration of a 238 Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly.

    Science.gov (United States)

    Aguiar, Julio C; Galiano, Eduardo; Arenillas, Pablo

    2005-08-01

    The activity concentration of a (238)Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb alpha particles, but reduce their energy by an average of 22 keV.A mean activity concentration for (238)Pu of 359.10+/-0.8 kBq/g was measured.

  15. Determination of the activity concentration of a {sup 238}Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Julio C. [Departamento de Postgrado, Universidad Tecnologica Nacional, Buenos Aires (Argentina); Galiano, Eduardo [Departament of Physics, Laurentian University, Sudbury, Ont. P3E 2C6 (Canada)]. E-mail: egalianoriveros@laurentian.ca; Arenillas, Pablo [Comision Nacional de Energia Atomica, CAE, Laboratorio de Metrologia de Radioisotopos, Buenos Aires (Argentina)

    2005-08-01

    The activity concentration of a {sup 238}Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb {alpha} particles, but reduce their energy by an average of 22keV.A mean activity concentration for {sup 238}Pu of 359.10+/-0.8kBq/g was measured.

  16. Determination of the activity concentration of a 238Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly

    International Nuclear Information System (INIS)

    Aguiar, Julio C.; Galiano, Eduardo; Arenillas, Pablo

    2005-01-01

    The activity concentration of a 238 Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb α particles, but reduce their energy by an average of 22keV.A mean activity concentration for 238 Pu of 359.10+/-0.8kBq/g was measured

  17. Mathematical modeling of radiation-chemical processes in HNO3 solutions of Pu. 5. Effect of [HNO3] on rate constants of radiation-chemical and chemical reactions of Pu ions

    International Nuclear Information System (INIS)

    Vladimirova, M.V.

    1993-01-01

    Dependences of rate constants on [HNO 3 ] are obtained for the reactions Pu(IV) + OH, Pu(IV) + NO 3 , Pu(V) + NO 2 , Pu(III) + NO 2 , Pu(V) + Pu(III), Pu(IV) + Pu(IV), and Pu(V) + Pu(V). These dependences are obtained for [HNO 3 ] = 0.3-6 M using existing experimental and literature data and the data obtained using mathematical modeling. The correctness of the resulting dependences is checked by comparing the calculated and experimental kinetic laws for the behavior of Pu in 0.3, 0.4, 0.6, and 1.6 M HNO 3 . 17 refs., 15 figs., 2 tabs

  18. Redox thermodynamic data of plutonium in acidic and carbonate media. Pu(V) stability

    International Nuclear Information System (INIS)

    Capdevila, H.

    1992-01-01

    Pu redox equilibria are studied in acidic and carbonate media in this thesis, to build a thermodynamic data bank consistent with the TDB (NEA-OECD) one and in connection with radioactive waste disposal programs. Literature is discussed and reinterpreted. The experimental method is tested with Uranium preliminary measurements. The reversible redox potentials (PuO 2 + and Pu 4+ /Pu 3+ ) are measured using the cyclic voltametric technique in perchloric media at several ionic strengths (from 0.5 to 3M) and temperatures (from 0 to 70 deg C). The Specific Interaction Theory (SIT) is used to measured activity coefficients and to extrapolate data to the standard conditions. The potentials variations versus temperature are linear in first approximation: the entropy changes are found constant from 0 to 70 deg C and the heat capacity changes are within uncertainties. The standard constant of PuO 2 + disproportionation into PuO 2 2+ and Pu 3+ is deduced from spectrophotometric measurements performed in perchloric media around pH=1 where Pu 4+ hydrolysis is discussed. The Pu non-reversible standard potentials (PuO 2 2+ /Pu 4+ for instance) are then calculated and validated with a spectrophotometric study of Pu 4+ formation from PuO 2 2+ and Pu 3+ in a 1M perchloric acidic solution. The Pu(VI/V) redox potential, activity coefficients and entropies are measured using the same technique in concentrated carbonate media. The limiting complex standard formation constants and the redox potential shifts (between acidic and carbonate media) are then discussed among the U, Np, Pu and Am actinides. A spectrophotometric study of the equilibrium between the complexes with 5 and 4 carbonate ligands allowed to measure Pu(IV) limiting complex stability at several ionic strengths. (author). 26 tabs., 46 figs., 95 refs

  19. Calculated K-effectives using ENDF/B-V data for U + Pu solution critical experiments

    International Nuclear Information System (INIS)

    Primm, R.T. III; Mincey, J.F.

    1981-01-01

    Effective multiplication factors for 12 critical experiments have been calculated using multigroup cross sections derived from the ENDF/B-V library. All 12 experiments contained mixed plutonium and uranium nitrate solutions. The range of hydrogen-to-fissile plutonium atom ratios spanned by these experiments was 200 to 2200. A comparison with K-effectives calculated with ENDF/B-IV data is presented

  20. Thermal conductivity of (Np0.20Pu0.50Am0.25Cm0.05)O2−x solid solutions

    International Nuclear Information System (INIS)

    Nishi, Tsuyoshi; Takano, Masahide; Akabori, Mitsuo; Arai, Yasuo

    2013-01-01

    Highlights: • Thermal conductivity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 2−x was evaluated. • Dependence of thermal conductivity on storage time was clarified. • Results were discussed with the lattice expansion model by self-irradiation. • After annealing at 1423 K in vacuum, thermal conductivity returned. -- Abstract: The authors prepared the sintered sample of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 2−x (2 − x = 1.98, 1.96) solid solution and evaluated the dependence of the thermal conductivity on storage time and temperature. The heat capacity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 1.98 was measured between 324 and 1082 K by a drop calorimetry. The thermal diffusivity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 1.98 was measured when the storage time became 48, 216, 720 and 1584 h and that of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 1.96 was measured when the storage time became 0,528 and 1386 h. In this study, the latter sample was annealed at 1423 K in vacuum with background pressure of less than 2.0 × 10 −4 Pa just after the measurement on the storage time, 1386 h. The thermal diffusivity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 1.96 just after annealing returned to the values of the storage time, 0 h. This result reveals the thermal recovery behavior by annealing. The thermal conductivity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 2−x was determined from the measured thermal diffusivity, heat capacity and bulk density. The thermal conductivity of (Np 0.20 Pu 0.50 Am 0.25 Cm 0.05 )O 2−x exponentially decreased with increasing storage time. This result suggested that the decrease of the thermal conductivity was attributed to the accumulation of lattice defects caused by self-irradiation

  1. Extraction of Am, Pu and U by dicyclohexano-18-crown-6/1-octanol from HNO3 solution and simulated HLLW

    International Nuclear Information System (INIS)

    Wang Xinghai; Wang Jianchen; Liu Xiuqin; Song Chongli

    1999-01-01

    The extraction of americium, plutonium and uranium by dicyclohexano-18-crown-6 (DCH18C6)/1-octanol from HNO 3 solution and simulated HLLW are studied. The influences of acidity and dilution factor of simulated HLLW are studied. At low HNO 3 concentration and dilution factor above 2, 0.1 mol/L DCH18C6/1-octanol extracts very little americium, plutonium and uranium. the distribution ratios of Am, Pu and U increase with the increase of HNO 3 concentration in aqueous phase, and decrease with increasing of dilution factor of HLLW. The distribution ratio of extraction of Pu(IV) increases with the increase of extractant concentration

  2. Determination of the solubility of Np(IV), Pu(III) - (VI),Am(III) - (VI), and Te(IV), (V) hydroxo compounds in 0.5 - 14 M NaOH solutions

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H.

    1996-09-24

    The solubilities of Am(III), Np(IV), Pu(IV), Tc(IV), Np(V), Pu(V), Am(V), and Tc(V) hydroxo compounds were studied in 0.5 to 14 M NaOH solutions at 25{+-}2 {degrees}C. The effects of fluoride, phosphate, carbonate, oxalate, and some other organic complexing agents on the solubilities of Np(IV), Pu(IV), and TC(IV) hydroxides were investigated at 1.0 and 4.0 M NAOH. Some predictions were made on the dissolved (I.V) and (V) species present in alkali solutions.

  3. Development of a process for co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder using microwave heating method

    International Nuclear Information System (INIS)

    Koizumi, Masumichi; Ohtsuka, Katsuyuki; Ohshima, Hirofumi; Isagawa, Hiroto; Akiyama, Hideo; Todokoro, Akio; Naruki, Kaoru

    1983-01-01

    For the complete nuclear fuel cycle, the development of a process for the co-conversion of Pu-U nitrate mixed solutions to mixed oxide powder has been performed along the line of non-proliferation policy of nuclear materials. A new co-conversion process using a microwave heating method has been developed and successfully demonstrated with good results using the test unit with a capacity of 2 kg MOX/d. Through the experiments and engineering test operations, several important data have been obtained concerning the feasibility of the test unit, powder characteristics and homogeneity of the product, and impurity pickups during denitration process. The results of these experimental operations show that the co-conversion process using a microwave heating method has many excellent advantages, such as good powder characteristics of the product, good homogeneity of Pu-U oxide, simplicity of the process, minimum liquid waste, no possibility of changing the Pu/U ratio and stable operability of the plant. Since August 1979, plutonium nitrate solution transported from the Tokai Reprocessing Plant has been converted to mixed oxide powder which has the Pu/U ratio = 1. The products have been processed to the ATR ''FUGEN'' reloading fuel. Based on the successful development of the co-conversion process, the microwave heating direct denitration facility with a 10 kg MOX/d capacity has been constructed adjacent to the reprocessing plant. This facility will come into hot operation by the fall of this year. For future development of the microwave heating method, a continuous direct denitration, a vitrification of high active liquid waste and a solidification of the plutonium-contaminated waste are investigated in Power Reactor and Nuclear Fuel Development Corp. (author)

  4. The role of pore soil solutions in redistribution of 137Cs, 90Sr, 239,240Pu and 241Am within soil-vegetative cover

    International Nuclear Information System (INIS)

    Ovsiannikova, S.V.; Sokolik, G.A.; Kilchitskaya, S.L.; Eismont, E.A.; Zhukovich, N.V.; Kimlenko, I.M.

    1998-01-01

    The role of pore soil solutions in the migration of 137 Cs, 90 Sr, 239,240 Pu and 241 Am within soil-vegetative cover of natural ecosystems was examined. The soil solutions were found to play an important role in the redistribution of 137 Cs, 90 Sr, 239,240 Pu and 241 Am in the soil-plant systems. Obvious relationships between the distribution coefficients of radionuclides between solid and liquid phases (K d ) and the intensity of vertical migration of 137 Cs, 90 Sr, 239,240 Pu and 241 Am along the soil profiles and with intensity of their accumulation by grass vegetation of natural meadows have been obtained. It means that the distribution coefficient may be used as a criterion of the radionuclide mobility in the soil-plant system whatever its level of radioactive contamination is. The influence of the degree of soil moistening, the content of mobile radionuclide forms in the soils and some characteristics of pore soil solutions (pH, content of K + , Ca 2+ , NH 4 + , water soluble organic substances) on the concentration of radionuclide in the soil solutions and on the value of radionuclide distribution coefficient have been analysed. The results of investigation are of great importance in the evaluation of radioecological situation and in solution of problems of radioecological rehabilitation of the contaminated territories. The received data constitute a part of scientific basis for the development of a system of countermeasures to decrease the mobility and biological availability of radionuclides of high and very high radiotoxicity

  5. Contribution to the study of the upper valence states of Pu

    International Nuclear Information System (INIS)

    Musante, Yves.

    1975-01-01

    The properties of the Pu(VI) and Pu(VII) ions in aqueous solutions were investigated: spectrophotometric study of the formation of PuO 2 2+ complexes with hydroxyl ions; electrochemical study of PuO 2 2+ ; preparation, determination and coprecipitation of Pu(VII); electrochemical study of Pu(VII). A preliminary research was made on the chemistry of Pu in non-aqueous solutions especially the dissolution and the determination of Pu in propylene carbonate [fr

  6. 11-year field study of Pu migration from Pu III, IV, and VI sources

    International Nuclear Information System (INIS)

    Kaplan, D.I.; Serkiz, S.M.; Demirkanli, D.I.; Gumapas, L.; Fjeld, R.A.; Molz, F.J.; Powell, B.A.

    2005-01-01

    Full text of publication follows: Understanding the processes controlling Pu mobility in the subsurface environment is important for estimating the amount of Pu waste that can be safely disposed in vadose zone burial sites. To study long-term Pu mobility, four 52-L lysimeters filled with sediment collected from the Savannah River Site near Aiken South Carolina were amended with well characterized solid Pu sources (Pu III Cl 3 , Pu IV (NO 3 ) 4 , Pu IV (C 2 O 4 ) 2 , and Pu VI O 2 (NO 3 ) 2 ) and left exposed to natural precipitation for 2 to 11 years. Pu oxidation state distribution in the Pu(III) and Pu(IV) lysimeters sediments (a red clayey sediment, pH = 6.3) were similar, consisting of 0% Pu(III), >92% Pu(IV), 1% Pu(V), 1% Pu(VI), and the remainder was a Pu polymer. These three lysimeters also had near identical sediment Pu concentration profiles, where >95% of the Pu remained within 1.25 cm of the source after 11 years; moving at an overall rate of 0.9 cm yr -1 . As expected, Pu moved more rapidly through the Pu(VI) lysimeter, at an overall rate of 12.5 cm yr -1 . Solute transport modeling of the sediment Pu concentration profile data in the Pu(VI) lysimeter indicated that some transformation of Pu into a much less mobile form, presumably Pu(IV), had occurred during the course of the two year study. This modeling also supported previous laboratory measurements showing that Pu(V) or Pu(VI) reduction was five orders of magnitude faster than corresponding Pu(III) or Pu(IV) oxidation. The slow oxidation rate (1 x 10-8 hr -1 ; t 1/2 = 8,000 yr) was not discernable from the Pu(VI) lysimeter data that reflected only two years of transport but was readily discernable from the Pu(III) and Pu(IV) lysimeter data that reflected 11 yr of transport. (authors)

  7. Designing Pu600 for Authentication

    International Nuclear Information System (INIS)

    White, G.

    2008-01-01

    Many recent Non-proliferation and Arms Control software projects include an authentication component. Demonstrating assurance that software and hardware performs as expected without hidden 'back-doors' is crucial to a project's success. In this context, 'authentication' is defined as determining that the system performs only its intended purpose and performs that purpose correctly and reliably over many years. Pu600 is a mature software solution for determining the presence of Pu and the ratio of Pu240 to Pu239 by analyzing the gamma ray spectra in the 600 KeV region. The project's goals are to explore hardware and software technologies which can by applied to Pu600 which ease the authentication of a complete, end-to-end solution. We will discuss alternatives and give the current status of our work

  8. Designing Pu600 for Authentication

    Energy Technology Data Exchange (ETDEWEB)

    White, G

    2008-07-10

    Many recent Non-proliferation and Arms Control software projects include an authentication component. Demonstrating assurance that software and hardware performs as expected without hidden 'back-doors' is crucial to a project's success. In this context, 'authentication' is defined as determining that the system performs only its intended purpose and performs that purpose correctly and reliably over many years. Pu600 is a mature software solution for determining the presence of Pu and the ratio of Pu240 to Pu239 by analyzing the gamma ray spectra in the 600 KeV region. The project's goals are to explore hardware and software technologies which can by applied to Pu600 which ease the authentication of a complete, end-to-end solution. We will discuss alternatives and give the current status of our work.

  9. Synthesis, characterization, kinetic and thermodynamic studies of the dissolution of ThO2 and of solid solutions Th1-xMxO2 (M = U, Pu)

    International Nuclear Information System (INIS)

    Heisbourg, G.

    2003-12-01

    The aim of this work was to understand the mechanisms of dissolution of ThO 2 and of thorium mixed oxides such as Th 1-x U x O 2 and Th 1-x Pu x O 2 in aqueous, oxygenated or inert media. Several solids have been synthesized by precipitation in oxalic medium: Th 1-x U x O 2 (x= 0.11; 0.24; 0.37; 0.53; 0.67; 0.81 and 0.91) and Th 1-x Pu x O 2 (x= 0.13; 0.32 and 0.66). They have been characterized by XRD, SEM, TEM, XPS, XAS, PIXE and EPMA. The sintering conditions of these materials have been studied and optimized in order to obtain sintered samples with a measured density very near the theoretical densities. A kinetic study of the dissolution of ThO 2 and of solid solutions Th 1-x U x O 2 has been carried out in several aqueous media (HNO 3 , HCl, H 2 SO 4 ) in terms of several parameters: protons concentration, temperature, pH, ionic strength, nature of the electrolyte solution and uranium molar ratio for the solid solutions Th 1-x U x O 2 in order to determine the kinetic laws of dissolution of the solid solutions having different compositions comparatively to ThO 2 . The leaching tests carried out in natural waters of compositions near those of the deep geologic sites considered for the storage of nuclear wastes have shown that the dissolution of the solids was bound to the complexing effect of the constitutional ions of the water considered. The leaching tests carried out on sintered samples of the same composition have led to the same normalized dissolution velocities. The thermodynamic aspect of the dissolution of the solid solutions Th 1-x U x O 2 in nitric medium has been studied at last. (O.M.)

  10. Biphasic kinetic investigations on the evaluation of non-salt forming reductants for Pu(IV) stripping from tributyl phosphate and N,N-dihexyl octanamide solutions in n-dodecane

    International Nuclear Information System (INIS)

    Prabhu, D.R.; Neelam Kumari; Kanekar, A.S.; Pathak, P.N.

    2013-01-01

    The relative stability of different oxidation states of actinide elements is influenced by the nature of complexes formed and redox equilibria in aqueous/non-aqueous solutions. The reduction/stripping studies on Pu(IV) ions from loaded organic phases of 1.1 M tributyl phosphate and of 1.1 M N,N-dihexyl octanamide in n-dodecane were studied using organic soluble tert-butyl hydroquinone (TBH) and aqueous soluble reductants like acetaldoxime (AX) and hydroxyurea (HU). These studies were carried out as a function of reductant and nitric acid concentration (0.5-4 M HNO 3 ) and of time. The changes in Pu oxidation states were followed by spectrophotometry for TBH and by distribution ratio values for AX and HU as reductants. Spectrophotometric investigations using TBH as reductant showed that it was desirable to strip Pu(III) formed after reduction of Pu(IV) in the organic phase, which may otherwise be reconverted to extractable Pu(IV) by in situ generated HNO 2 from oxidative degradation of TBH to tert-butyl quinone. Similarly, the biphasic reduction/stripping of Pu(IV) using AX and HU as reductant rate was affected adversely with increased aqueous phase acidity. This data will help in the accurate simulation of Pu separation processes using these reductants in mixer-settlers/pulsed columns or centrifugal contactors. (author)

  11. Covariant two-particle wave functions for model quasipotential allowing exact solutions

    International Nuclear Information System (INIS)

    Kapshaj, V.N.; Skachkov, N.B.

    1982-01-01

    Two formulations of quasipotential equations in the relativistic configurational representation are considered for the wave function of relative motion of a bound state of two relativistic particles. Exact solutions of these equations are found for some model quasipotentials

  12. Multi-isotopic determination of plutonium (239Pu, 240Pu, 241Pu and 242Pu) in marine sediments using sector-field inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Donard, O F X; Bruneau, F; Moldovan, M; Garraud, H; Epov, V N; Boust, D

    2007-03-28

    Among the transuranic elements present in the environment, plutonium isotopes are mainly attached to particles, and therefore they present a great interest for the study and modelling of particle transport in the marine environment. Except in the close vicinity of industrial sources, plutonium concentration in marine sediments is very low (from 10(-4) ng kg(-1) for (241)Pu to 10 ng kg(-1) for (239)Pu), and therefore the measurement of (238)Pu, (239)Pu, (240)Pu, (241)Pu and (242)Pu in sediments at such concentration level requires the use of very sensitive techniques. Moreover, sediment matrix contains huge amounts of mineral species, uranium and organic substances that must be removed before the determination of plutonium isotopes. Hence, an efficient sample preparation step is necessary prior to analysis. Within this work, a chemical procedure for the extraction, purification and pre-concentration of plutonium from marine sediments prior to sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) analysis has been optimized. The analytical method developed yields a pre-concentrated solution of plutonium from which (238)U and (241)Am have been removed, and which is suitable for the direct and simultaneous measurement of (239)Pu, (240)Pu, (241)Pu and (242)Pu by SF-ICP-MS.

  13. Calculating excess volumes of binary solutions with allowance for structural differences between mixed components

    Science.gov (United States)

    Balankina, E. S.

    2016-06-01

    Analytical dependences of a volume's properties on the differences between the geometric structures of initial monosystems are obtained for binary systems simulated by a grain medium. The effect of microstructural parameter k (the ratio of volumes of molecules of mixed components) on the concentration behavior of the relative excess molar volume of different types of real binary solutions is analyzed. It is established that the contribution due to differences between the volumes of molecules and coefficients of the packing density of mixed components is ~80-100% for mutual solutions of n-alkanes and ~55-80% of the experimental value of the relative excess molar volume for water solutions of n-alcohols.

  14. Self-irradiation effect on thermal conductivity of Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, Tsuyoshi, E-mail: tsuyoshi.nishi.75@vc.ibaraki.ac.jp [Department of Materials Science and Engineering, College of Engineering, Ibaraki University, Hitachi, Ibaraki, 316-8511 (Japan); Hayashi, Hirokazu; Sato, Takumi; Takano, Masahide [Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai-mura, Ibaraki, 319-1195 (Japan)

    2017-04-01

    This study evaluated the dependence of the thermal conductivity of Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N on storage time and temperature. The authors prepared sintered samples of Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N solid solution and measured thermal diffusivity at storage times of 0, 24, 72, 144, 240, 408, 552, 816, 1,680, and 2064 h, from which it was determined that the thermal conductivity decreased exponentially with increasing storage time. This result suggests that the decrease of the thermal conductivity could be attributed to the accumulation of lattice defects from self-irradiation. To confirm the thermal recovery behavior of Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N under annealing, thermal diffusivity was also measured just after annealing. The thermal conductivity of Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N was determined to be larger than that of Zr{sub 0.58}Pu{sub 0.21}Cm{sub 0.21}N but smaller than that of Zr{sub 0.80}Pu{sub 0.10}Cm{sub 0.10}N. - Highlights: •The authors prepared Zr{sub 0.70}Pu{sub 0.25}Cm{sub 0.05}N and measured thermal diffusivity. •Dependence of thermal conductivity on storage time was clarified. •After annealing at 1423 K in vacuum, thermal conductivity was recovered.

  15. Exact solutions of the vacuum Einstein's equations allowing for two noncommuting Killing vectors

    International Nuclear Information System (INIS)

    Aliev, V.N.; Leznov, A.N.

    1990-01-01

    Einstein's equations are written in the form of covariant gauge theory in two-dimensional space with binomial solvable gauge group, with respect to two noncommutative of Killing vectors. The theory is exact integrable in one-dimensional case and series of partial exact solutions are constructed in two-dimensional. 5 refs

  16. (1-xPux)Sb solid solutions. 1. Magnetic configurations

    DEFF Research Database (Denmark)

    Normile, P.S.; Stirling, W.G.; Mannix, D.

    2002-01-01

    Neutron and resonant x-ray magnetic scattering studies have been performed on single crystals of three compositions, x=0.25, 0.50, and 0.75 of the (U1-xPux)Sb solid solution. Neutron diffraction has established the ordering wave vector (k=1 for x=0.25 and 0.50, as in x=0, USb, and k=0.25 for x=0....

  17. Computing and physical methods to calculate Pu

    International Nuclear Information System (INIS)

    Mohamed, Ashraf Elsayed Mohamed

    2013-01-01

    Main limitations due to the enhancement of the plutonium content are related to the coolant void effect as the spectrum becomes faster, the neutron flux in the thermal region tends towards zero and is concentrated in the region from 10 Ke to 1 MeV. Thus, all captures by 240 Pu and 242 Pu in the thermal and epithermal resonance disappear and the 240 Pu and 242 Pu contributions to the void effect became positive. The higher the Pu content and the poorer the Pu quality, the larger the void effect. The core control in nominal or transient conditions Pu enrichment leads to a decrease in (B eff.), the efficiency of soluble boron and control rods. Also, the Doppler effect tends to decrease when Pu replaces U, so, that in case of transients the core could diverge again if the control is not effective enough. As for the voiding effect, the plutonium degradation and the 240 Pu and 242 Pu accumulation after multiple recycling lead to spectrum hardening and to a decrease in control. One solution would be to use enriched boron in soluble boron and shutdown rods. In this paper, I discuss and show the advanced computing and physical methods to calculate Pu inside the nuclear reactors and glovebox and the different solutions to be used to overcome the difficulties that effect, on safety parameters and on reactor performance, and analysis the consequences of plutonium management on the whole fuel cycle like Raw materials savings, fraction of nuclear electric power involved in the Pu management. All through two types of scenario, one involving a low fraction of the nuclear park dedicated to plutonium management, the other involving a dilution of the plutonium in all the nuclear park. (author)

  18. Electronic structure of Pu-Ce(-Ga) and Pu-Am(-Ga) alloys, stabilized in the {delta} phase; Structure electronique d'alliages Pu-Ce(-Ga) et Pu-Am(-Ga) stabilises en phase {delta}

    Energy Technology Data Exchange (ETDEWEB)

    Dormeval, M

    2001-09-01

    The behaviour of {delta}-plutonium, stable between 319 and 451 deg C, exhibits numerous singularities which are still a mystery for both physicists and metallurgists. This is due to its complex electronic structure, and in particular to the 5f electrons, which are at the edge between localization and delocalization. The stability domain of the {delta} phase can be extended down to room temperature by alloying with so called 'deltagen atoms' such as gallium (Ga), aluminum (A1), cerium (Ce) or americium (Am). The present work deals, one the one hand, with the influence of cerium and americium solutes regarding the localization of the 5f electrons of {delta}-plutonium, in binary Pu-Ce and Pu-Am alloys. On the other hand, the effect of two different deltagen solutes, simultaneously present, on the stability of the {delta} phase has been studied in ternary Pu-Am-Ga and Pu-Ce-Ga alloys. The electronic structure being strongly related to the crystalline organization, characterization methods such as X-Ray diffraction and EXAFS measurements were used together with electrical resistivity and magnetic susceptibility experiments. These showed that the roles of cerium and americium, supposed to be similar at the beginning of this investigation, are actually very different. Moreover, the additive effect of cerium and gallium, and, americium and gallium, has been demonstrated. Studying plutonium alloys, which are radioactive, also means following their evolution in time. The characteristics of the alloys have then been followed which allowed to detect, in Pu-Ce(-Ga) alloys, a destabilization of the {delta} phase and, to observe, in Pu-Am(-Ga) alloys, the influence of self-irradiation defects on the magnetic response. (author)

  19. Electronic structure of Pu-Ce(-Ga) and Pu-Am(-Ga) alloys, stabilized in the {delta} phase; Structure electronique d'alliages Pu-Ce(-Ga) et Pu-Am(-Ga) stabilises en phase {delta}

    Energy Technology Data Exchange (ETDEWEB)

    Dormeval, M

    2001-09-01

    The behaviour of {delta}-plutonium, stable between 319 and 451 deg C, exhibits numerous singularities which are still a mystery for both physicists and metallurgists. This is due to its complex electronic structure, and in particular to the 5f electrons, which are at the edge between localization and delocalization. The stability domain of the {delta} phase can be extended down to room temperature by alloying with so called 'deltagen atoms' such as gallium (Ga), aluminum (A1), cerium (Ce) or americium (Am). The present work deals, one the one hand, with the influence of cerium and americium solutes regarding the localization of the 5f electrons of {delta}-plutonium, in binary Pu-Ce and Pu-Am alloys. On the other hand, the effect of two different deltagen solutes, simultaneously present, on the stability of the {delta} phase has been studied in ternary Pu-Am-Ga and Pu-Ce-Ga alloys. The electronic structure being strongly related to the crystalline organization, characterization methods such as X-Ray diffraction and EXAFS measurements were used together with electrical resistivity and magnetic susceptibility experiments. These showed that the roles of cerium and americium, supposed to be similar at the beginning of this investigation, are actually very different. Moreover, the additive effect of cerium and gallium, and, americium and gallium, has been demonstrated. Studying plutonium alloys, which are radioactive, also means following their evolution in time. The characteristics of the alloys have then been followed which allowed to detect, in Pu-Ce(-Ga) alloys, a destabilization of the {delta} phase and, to observe, in Pu-Am(-Ga) alloys, the influence of self-irradiation defects on the magnetic response. (author)

  20. Determination of {sup 240}Pu/{sup 239}Pu ratio and its significance in environmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-03-01

    Analytical procedures for the determination of Pu concentrations and its isotopic ratios in environmental samples were developed by using ICP-MS. Detection limit of Pu by ICP-MS was about 0.02 pg ml{sup -1} (0.05 mBq ml{sup -1} for {sup 239}Pu; 0.17 mBq ml{sup -1} for {sup 240}Pu) in the sample solution. Analytical results of {sup 239+240}Pu in IAEA standard reference materials indicated that the accuracy of this method was satisfactory. Data on the {sup 240}Pu/{sup 239}Pu atom ratios, which are rare in the literature, were also obtained for soil and sediment samples (including IAEA standard reference materials) from different areas such as Irish Sea, Mururoa Atoll, Marshall Islands, Chernobyl, Kyshtym, Nagasaki and some other places in Japan. The range of the {sup 240}Pu/{sup 239}Pu ratios was about 0.04-0.4, and the ratios are depending on the origin of the materials. Analytical results for the {sup 240}Pu/{sup 239}Pu atom ratios provide information about the source of the contamination and the transfer of plutonium in the environment. (author)

  1. Nitrate Anion Exchange in Pu-238 Aqueous Scrap Recovery Operations

    International Nuclear Information System (INIS)

    Pansoy-Hjelvik, M.E.; Silver, G.L.; Reimus, M.A.H.; Ramsey, K.B.

    1999-01-01

    Strong base, nitrate anion exchange (IX) is crucial to the purification of 238 Pu solution feedstocks with gross levels of impurities. This paper discusses the work involved in bench scale experiments to optimize the nitrate anion exchange process. In particular, results are presented of experiments conducted to (a) demonstrate that high levels of impurities can be separated from 238 Pu solutions via nitrate anion exchange and, (b) work out chemical pretreatment methodology to adjust and maintain 238 Pu in the IV oxidation state to optimize the Pu(IV)-hexanitrato anionic complex sorption to Reillex-HPQ resin. Additional experiments performed to determine the best chemical treatment methodology to enhance recovery of sorbed Pu from the resin, and VIS-NIR absorption studies to determine the steady state equilibrium of Pu(IV), Pu(III), and Pu(VI) in nitric acid are discussed

  2. Liquid chromatographic studies on the behaviour of Pu(III), Pu(IV) and Pu(VI) on a RP stationary phase in presence of α-hydroxyisobutyric acid as a chelating agent

    Energy Technology Data Exchange (ETDEWEB)

    Jaison, P.G.; Kumar, Pranaw; Telmore, Vijay M. [Bhabha Atomic Research Centre, Mumbai (India). Fuel Chemistry Division

    2017-06-01

    Since plutonium possesses multiple oxidation states which can coexist in solution, a method for the identification of these oxidation states is important to understand its chemical processes. Liquid chromatographic studies were carried out to compare the chromatographic behaviour of different oxidation states of Pu in presence of the eluent, α-hydroxyisobutyric acid (HIBA). The three oxidation states of Pu viz. Pu(III), Pu(IV) and Pu(VI) were separated under optimised conditions. It was seen that the presence of the complexing agent influences the equilibrium of Pu(III)/(IV) as well as Pu(IV)/(VI) systems. Pu(III) to Pu(IV) conversion was found to be enhanced by high pH and concentration of HIBA whereas a relatively low pH and high concentration of HIBA promotes the conversion of Pu(VI) to Pu(IV).

  3. Simultaneous measurement of 239Pu, 240Pu, 241Pu, and 242Pu by high resolution inductively coupled plasma mass spectrometer (HR ICP-MS) in marine sediments

    International Nuclear Information System (INIS)

    Bruneau, F.

    1999-01-01

    Transuranics elements are of particular interest in radioecological studies because of their radiotoxicity and their potential use to decipher source fingerprints and transport processes. The simultaneous measurement of 239 Pu, 240 Pu, 241 Pu, and 242 Pu in environmental samples requires a specific chemical procedure. This work deals with an analytical procedure which yields a very high grade of purification of Pu suitable for ultra low level detection by HR ICP-MS, from marine sediments. After the elimination of major elements (Fe, Al, Mg...) by a first chromatographic separation, a new device of purification by solvent extraction and concentration by a second chromatographic separation is used to obtain a concentrated and high purified solution of plutonium. The chemical procedure have been validated on IAEA certified sediment samples and on sediment samples collected in the roads of Cherbourg which had been previously analysed by other techniques (a spectrometry and thermo-ionisation mass spectrometer). (author)

  4. Pu(V) as the stable form of oxidized plutonium in natural waters

    International Nuclear Information System (INIS)

    Orlandini, K.A.; Penrose, W.R.; Nelson, D.M.

    1986-01-01

    This work presents analytical evidence supporting the proposition that Pu(V) is the sole or predominant form of oxidized plutonium in natural waters. Two independent methods, the selective adsorption of Pu(VI) by silica gel, and the somewhat less selective coprecipitation of Pu(V) with calcium carbonate, were developed to separate Pu(V) from Pu(VI). Measurements of ambient plutonium in several natural waters by these methods found only Pu(V). In laboratory tracer studies, Pu(VI) was shown to be highly unstable in dilute bicarbonate solution and in Lake Michigan water, reducing in first-order fashion to Pu(V). (orig.)

  5. Studies in the solubility of Pu(III) oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Hasilkar, S P; Khedekar, N B; Chander, K; Jadhav, V; Jain, H C [Bhabha Atomic Research Centre, Bombay (India). Fuel Reprocessing Div.

    1994-11-01

    Studies have been carried out on the solubility of Pu(III) oxalate by precipitation of Pu(III) oxalate from varying concentrations of HNO[sub 3]/HCl (0.5-2.0M) solutions and also by equilibrating freshly prepared Pu(III) oxalate with solutions containing varying concentrations of HNO[sub 3]/HCl, oxalic acid and ascorbic acid. Pu(III) solutions in HNO[sub 3] and HCl media were prepared by reduction of Pu(IV) with ascorbic acid. 0.01-0.10M ascorbic acid concentration in the aqueous solution was maintained as holding reductant. The solubility of Pu(III) oxalate was found to be a minimum in 0.5M-1M HNO[sub 3]/HCl solutions containing 0.05M ascorbic acid and 0.2M excess oxalic acid in the supernatant. (author) 6 refs.; 6 tabs.

  6. Reversed phase chromatographic behaviour of Pu (III), Pu (IV) and Pu (VI) in presence of α-hydroxyisobutyric acid

    International Nuclear Information System (INIS)

    Jaison, P.G.; Telmore, V.M.; Kumar, Pranaw

    2016-01-01

    Understanding the aqueous chemistry of plutonium is important in process conditions as well as in environmental conditions. Since plutonium possesses multiple oxidation states which can coexist in solution, a reliable method for the identification of these oxidation states is essential to understand its physical and chemical processes. The identification of plutonium oxidation states is conventionally determined through a series of liquid-liquid extraction procedures using selective extractants. Spectroscopic and laser based techniques also have been used for the identification of its oxidation state in solutions. Liquid chromatographic behavior of different oxidation states of Pu and other actinide ions is reported to correlate their retention behaviour with stability constants. Objective of the present work is to study the reversed phase chromatography behavior of the three oxidation states of plutonium viz. Pu(III), Pu(IV) and Pu(VI) in presence of á-hydroxyisobutyric acid (HIBA) as an eluent

  7. Determination of 239Pu/240Pu isotopic ratio by high resolution alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Amoudry, F.; Burger, P.

    1983-05-01

    The development of passivated ion-implanted silicon detectors and of very thin alpha-particle sources improves the resolution of alpha-particle spectra and allows to separate energy pics up to now unseparate. The 239 Pu/ 240 Pu isotopic ratio of a mixture has been measured using the alpha spectrometry deconvolution code DEMO [fr

  8. Irradiation alternative method of manganese sulfate solution by a Pu-Be source for efficiency measurements; Metodo alternativo de irradiacao da solucao de sulfato de manganes por uma fonte de Pu-Be para medicoes de eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fellipe Souza da; Martins, Marcelo Marques; Pereira, Walsan Wagner, E-mail: fellipess@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This study intends to create an alternative irradiation system from a Plutonium-Beryllium source for manganese sulphate solution using the Monte Carlo code. Thus seeking to eliminate the issue of institutes that do not have reactors or particle accelerators in its infrastructure, in order to optimize and provide independence for them to carry out efficiency measurements of MnSO{sub 4} solution in their own locality. The Monte Carlo simulations defined the technical features of this new system so that the solution reaches the maximum neutron capture by manganese in solution. (author)

  9. A 244Pu spike reference material CBNM IRM-042A

    International Nuclear Information System (INIS)

    Verbruggen, A.; Gallet, M.; Hendrickx, F.; Bievre, P. de

    1991-01-01

    An highly enriched 244 Pu isotopic reference material (CBNM IRM-042a) has been prepared and certified for 244 Pu isotope concentration. The certified value of (2.257 7 ± 0.004 4).10 18 atoms 242 Pu.kg -1 of solution has been established by isotope dilution mass spectrometry. The plutonium isotopic composition has been determined by thermal ionization mass spectrometry and calibration of these measurements by means of synthetic 242 Pu/ 239 Pu mixtures. The isotopic reference material is supplied in a sealed glass ampoule containing approximately 10 g of a 5M nitric acid solution at an approximate concentration of 1 μg Pu per g solution. This isotopic reference material is part of a systematic CBNM programme to supply spike isotopic reference materials of various isotopes at different concentrations

  10. Preliminary neutronic study on Pu-based OTTO cycle pebble bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Setiadipura, Topan; Zuhair [National Nuclear Energy Agency of Indonesia (BATAN), Selatan (Indonesia). Center for Nuclear Reactor Technology and Safety; Irwanto, Dwi [Bandung Institute of Technology (ITB), Bandung (Indonesia). Nuclear Physics and Biophysics Research Group

    2017-12-15

    The neutron physics characteristic of Pebble Bed Reactor (PBR) allows a better incineration of plutonium (Pu). An optimized design of simple PBR might give a symbiotic solution of providing a safe energy source, effective fuel utilization shown by a higher burnup value, and incineration of Pu stockpiles. This study perform a preliminary neutronic design study of a 200 MWt Once Through Then Out (OTTO) cycle PBR with Pu-based fuel. The safety criteria of the design were represented by the per-fuel-pebble maximum power generation of 4.5 kW/pebble. In this preliminary phase, the parametric survey is limited to the heavy metal (HM) loading per pebble and the average axial speed of the fuel. An optimum high burnup of 419.7 MWd/kg-HM was achieved in this study. This optimum design uses a HM loading of 2.5 g/pebble with average axial fuel velocity 0.5 cm/day.

  11. Determination of Pu Oxidation states in the HCl Media Using with UV-Visible Absorption Spectroscopic Techniques

    International Nuclear Information System (INIS)

    Lee, Myung Ho; Suh, Mu Yeol; Park, Kyoung Kyun; Park, Yeong Jae; Kim, Won Ho

    2006-01-01

    The spectroscopic characteristics of Pu (III, IV, V, VI) in the HCl media were investigated by measuring Pu oxidation states using a UV-Vis-NIR spectrophotometer (400-1200 nm) after adjusting Pu oxidation states with oxidation/reduction reagents. Pu in stock solution was reduced to Pu(III) with NH 2 OH · HCl, and oxidized to Pu(IV) and Pu(VI) with NaNO 2 and HCIO 4 , respectively. Also, Pu(V) was adjusted in the Pu(VI) solution with NH 2 OH · HCl. The major absorption peaks of Pu (IV) and Pu(III) were measured in the 470 nm and 600 nm, respectively. The major absorption peaks of Pu (VI) and Pu(V) were measured in the 830 nm and 1135 nm, respectively. There was not found to be significant changes of UV-V is absorption spectra for Pu(III), Pu(IV) and Pu(VI) with aging time, except that an unstable Pu(V) immediately reduced to Pu(III).

  12. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2005-01-01

    The complexation of radionuclides (e.g., plutonium (Pu) and 60 Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH) 3 (s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop Pu

  13. Procedure for plutonium determination using Pu(VI) spectra

    International Nuclear Information System (INIS)

    Walker, L.F.; Temer, D.J.; Jackson, D.D.

    1996-01-01

    This document describes a simple spectrophotometric method for determining total plutonium in nitric acid solutions based on the spectrum of Pu(VI). Plutonium samples in nitric acid are oxidized to Pu(VI) with Ce(IV) and the net absorbance at the 830 nm peak is measured

  14. Determination of isotope fractionation effect using a double spike (242Pu+240Pu) during the mass spectrometric analysis of plutonium

    International Nuclear Information System (INIS)

    Chitambar, S.A.; Parab, A.R.; Khodade, P.S.; Jain, H.C.

    1986-01-01

    Isotope fractionation effect during the mass spectrometric analysis of plutonium has been investigated using a double spike ( 242 Pu+ 240 Pu) and the determination of concentration of plutonium in dissolver solution of irradiated fuel is reported. (author). 6 refs., 2 tables

  15. Pu-239 and Pu-240 inventories and Pu-240/ Pu-239 atom ratios in the water column off Sanriku, Japan.

    Science.gov (United States)

    Yamada, Masatoshi; Zheng, Jian; Aono, Tatsuo

    2013-04-01

    A magnitude 9.0 earthquake and subsequent tsunami occurred in the Pacific Ocean off northern Honshu, Japan, on 11 March 2011 which caused severe damage to the Fukushima Dai-ichi Nuclear Power Plant. This accident has resulted in a substantial release of radioactive materials to the atmosphere and ocean, and has caused extensive contamination of the environment. However, no information is available on the amounts of radionuclides such as Pu isotopes released into the ocean at this time. Investigating the background baseline concentration and atom ratio of Pu isotopes in seawater is important for assessment of the possible contamination in the marine environment. Pu-239 (half-life: 24,100 years), Pu-240 (half-life: 6,560 years) and Pu-241 (half-life: 14.325 years) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-239 and Pu-240 inventories and Pu-240/Pu-239 atom ratios in seawater samples collected in the western North Pacific off Sanriku before the accident at Fukushima Dai-ichi Nuclear Power Plant will provide useful background baseline data for understanding the process controlling Pu transport and for distinguishing additional Pu sources. Seawater samples were collected with acoustically triggered quadruple PVC sampling bottles during the KH-98-3 cruise of the R/V Hakuho-Maru. The Pu-240/Pu-239 atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. The Pu-239 and Pu-240 concentrations were 2.07 and 1.67 mBq/m3 in the surface water, respectively, and increased with depth; a subsurface maximum was identified at 750 m depth, and the concentrations decreased with depth, then increased at the bottom layer. The total Pu-239+240 inventory in the entire water column (depth interval 0

  16. Ceramic grade (U,Pu)O2 powder fabrication

    International Nuclear Information System (INIS)

    Cristallini, O.A.; Villegas de Maroto, Marina; De Pino, J.I.; Osuna, H.A.

    1980-01-01

    Ceramic grade UO 2 powder was obtained by the homogeneous precipitation method. This procedure was afterwards applied to the fabrication of ceramic grade (U,Pu)O 2 powders, and mixed oxide powders with Pu content ranging from 0.7 to 16% were obtained. The obtainment of mixed ceramic oxides as well as the recuperation of fabrication scraps were developed in three steps: 1)study of the process of homogeneous precipitation of ammonium diuranate (ADU); 2) co-precipitation of ADU/PuO 2 .H 2 O for Pu concentrations of 0.6 and 6.8; 3) the thermal conditioning to mixed oxide (U,Pu)O 2 powders. The experimental procedure involves the following steps: preparation of the PuO 2 (NO 3 ) 4 solution; co-precipitation of the PuO 2 (NO 3 ) 2 solution with an UO 2 (NO 3 ) 2 solution; filtration and drying of the precipitate, thermal treatment and finally, mixing, pressing and sintering of the (U,Pu)O 2 and Nukem UO 2 powder with a 0. of zinc stearate. Different controls were made by means of physical, chemical and ceramographic tests. This method can be used for the fabrication of fast reactor fuels or, previous mechanical dispersion in UO 2 powder, for the fabrication of thermal reactors fuels. (M.E.L.) [es

  17. Evaluating 239Pu levels using field detectors

    International Nuclear Information System (INIS)

    Wahl, L.E.; Smith, W.J. II; Martin, B.

    1996-01-01

    At Los Alamos National Laboratory, cleanup was planned at three septic tanks where surface soil in the outfall drainage areas was found to be contaminated with 239 Pu. To meet budget and deadline constraints, a technique was developed that used field instruments to verify 239 Pu soil contamination at levels less than 2.8 Bq g -1 , the established cleanup level. The drainage areas were surveyed using a low-energy gamma probe to identify likely areas of 239 Pu contamination. Between 40 and 135 0.1-min gamma radiation measurements were obtained from each drainage area. From these data, locations were identified for subsequent screening for alpha radioactivity. Soil samples from between 11 and 18 locations at each drainage area were placed in petri dishes, dried, and counted for 10 minutes using an alpha probe. Alpha counts were then related to 239 Pu concentrations using a curve developed from local soils containing known concentrations of 239 Pu. Up to six soil samples from each drainage area, representing a range of alpha radioactivity levels, were sent for laboratory analysis of isotopic plutonium to confirm field measurement results. Analytical and field results correlated well at all but one outfall area. At this area, field measurements predicted more 239 Pu than was measured in the laboratory, indicating the presence of another alpha-emitting radionuclide that might have been missed if only laboratory analyses for plutonium had been used. This technique, which combined a large number of gamma radioactivity measurements, a moderate number of alpha radioactivity measurements, and a few isotopic plutonium measurements, allowed quick and inexpensive comparison of 239 Pu with the cleanup level

  18. Use of combined alpha-spectrometry and fission track analysis for the determination of 240Pu/239Pu ratios in human tissue

    International Nuclear Information System (INIS)

    Love, S.F.; Filby, R.H.; Glover, S.E.; Stuit, D.B.; Kathren, R.L.

    1998-01-01

    Plutonium and other actinides were determined in human autopsy tissues of occupationally exposed workers who were registrants of the United States Transuranium and Uranium Registries (USTUR). In this study, Pu was purified and isolated from Am, U and Th, after drying and wet-ashing of the tissues, and the addition of 238 Pu as a radiotracer. After electrodeposition onto vanadium planchets, the 239+240 Pu activity was determined by alpha-spectrometry. A fission track method was developed to determine 239 Pu in the presence of 238 Pu and 240 Pu, using Lexan TM polycarbonate detectors. Combining the two techniques allowed the determination of the 240 Pu/ 239 Pu activity and atom ratios. Data from selected USTUR cases are presented. (author)

  19. Synthesis, characterization, kinetic and thermodynamic studies of the dissolution of ThO{sub 2} and of solid solutions Th{sub 1-x}M{sub x}O{sub 2} (M = U, Pu); Synthese, caracterisation et etudes cinetique et thermodynamique de la dissolution de ThO{sub 2} et des solutions solides Th{sub 1-x}M{sub x}O{sub 2} (M = U, Pu)

    Energy Technology Data Exchange (ETDEWEB)

    Heisbourg, G

    2003-12-01

    The aim of this work was to understand the mechanisms of dissolution of ThO{sub 2} and of thorium mixed oxides such as Th{sub 1-x}U{sub x}O{sub 2} and Th{sub 1-x}Pu{sub x}O{sub 2} in aqueous, oxygenated or inert media. Several solids have been synthesized by precipitation in oxalic medium: Th{sub 1-x}U{sub x}O{sub 2} (x= 0.11; 0.24; 0.37; 0.53; 0.67; 0.81 and 0.91) and Th{sub 1-x}Pu{sub x}O{sub 2} (x= 0.13; 0.32 and 0.66). They have been characterized by XRD, SEM, TEM, XPS, XAS, PIXE and EPMA. The sintering conditions of these materials have been studied and optimized in order to obtain sintered samples with a measured density very near the theoretical densities. A kinetic study of the dissolution of ThO{sub 2} and of solid solutions Th{sub 1-x}U{sub x}O{sub 2} has been carried out in several aqueous media (HNO{sub 3}, HCl, H{sub 2}SO{sub 4}) in terms of several parameters: protons concentration, temperature, pH, ionic strength, nature of the electrolyte solution and uranium molar ratio for the solid solutions Th{sub 1-x}U{sub x}O{sub 2} in order to determine the kinetic laws of dissolution of the solid solutions having different compositions comparatively to ThO{sub 2}. The leaching tests carried out in natural waters of compositions near those of the deep geologic sites considered for the storage of nuclear wastes have shown that the dissolution of the solids was bound to the complexing effect of the constitutional ions of the water considered. The leaching tests carried out on sintered samples of the same composition have led to the same normalized dissolution velocities. The thermodynamic aspect of the dissolution of the solid solutions Th{sub 1-x}U{sub x}O{sub 2} in nitric medium has been studied at last. (O.M.)

  20. Comparison of U-Pu-Mo, U-Pu-Nb, U-Pu-Ti and U-Pu-Zr alloys; Comparaison des alliages U-Pu-Mo, U-Pu-Nb, U-Pu-Ti, U-Pu-Zr

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, R; Barthelemy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The data concerning the U-Pu, U-Pu-Mo and U-Pu-Nb are recalled. The results obtained with U-Pu-Ti and U-Pu-Zr alloys containing 15-20 per cent Pu and 10 wt. per cent ternary element are reported. The transformation temperatures, the expansion coefficients, the nature of phases, the thermal cycling behaviour have been determined. A list of the principal properties of these different alloys is presented and the possibilities of their use as fast reactor's fuel element are considered. The U-Pu-Ti alloys seem to be quite promising: easiness of fabrication, large thermal stability, excellent behaviour in air, small quantity of zeta phase, temperature of solidus superior to 1100 deg. C. (authors) [French] On rappelle brievement les connaissances acquises sur les alliages U-Pu, U-Pu-Mo et U-Pu-Nb. On presente les resultats obtenus avec les alliages U-Pu-Ti et U-Pu-Zr pour des teneurs de 15 a 20 pour cent de plutonium et 10 pour cent en poids d'element ternaire. On a determine les temperatures de transformation, les coefficients de dilatation, la nature des phases, la conductibilite thermique a 20 deg. C, la tenue au cyclage thermique et diverses autres proprietes. Un tableau resume les principales proprietes des divers alliages. On considere les possibilites d'emploi de ces alliages comme combustibles de reacteur rapide. Les alliages U-Pu-Ti paraissent particulierement interessants: facilite d'elaboration, stabilite thermique etendue, tenue dans l'air excellente, faible quantite de la phase U-Pu zeta, temperature de fusion commencante superieure a 1100 deg. C. (auteurs)

  1. Pu Anion Exchange Process Intensification

    International Nuclear Information System (INIS)

    Taylor-Pashow, Kathryn M. L.

    2017-01-01

    This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.

  2. Pu Anion Exchange Process Intensification

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, Kathryn M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-06

    This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.

  3. Chromatography of actinides on anion-exchange paper, behaviour of the elements U, Np Pu Am in acid, aqueous and alcohol-water solutions

    International Nuclear Information System (INIS)

    Collin, Michel

    1969-01-01

    A preliminary study of actinide migration on ion exchange paper has been carried out on trace amounts with a view to subsequent application in micro-analysis. The first tests have made it possible to define the factors having an effect on the migrational velocities of aqueous and alcohol-water solutions of HCl and HNO 3 . The behaviour, of actinides has then been studied in non-saline acid solutions. The results obtained for each element separately are interesting from the point of view of their mutual separation. This analytical technique has finally been applied successfully to the migration of 300 μg of uranium deposited from a 1 ml volume of solution. (author) [fr

  4. Comparison of U-Pu-Mo, U-Pu-Nb, U-Pu-Ti and U-Pu-Zr alloys

    International Nuclear Information System (INIS)

    Boucher, R.; Barthelemy, P.

    1964-01-01

    The data concerning the U-Pu, U-Pu-Mo and U-Pu-Nb are recalled. The results obtained with U-Pu-Ti and U-Pu-Zr alloys containing 15-20 per cent Pu and 10 wt. per cent ternary element are reported. The transformation temperatures, the expansion coefficients, the nature of phases, the thermal cycling behaviour have been determined. A list of the principal properties of these different alloys is presented and the possibilities of their use as fast reactor's fuel element are considered. The U-Pu-Ti alloys seem to be quite promising: easiness of fabrication, large thermal stability, excellent behaviour in air, small quantity of zeta phase, temperature of solidus superior to 1100 deg. C. (authors) [fr

  5. Pu-Th separation studies employing di(2-ethylhexyl)isobutyramide (D2EHIBA) as extractant from nitric acid medium

    International Nuclear Information System (INIS)

    Pathak, P.N.; Prabhu, D.R.; Rizvi, G.H.; Ruikar, P.B.; Kumbhare, L.B.; Mohapatra, P.K.; Manchanda, V.K.

    2003-01-01

    An attempt has been made to explore the use of di(2-ethylhexyl)isobutyramide (D2EHIBA) as an extractant for the recovery of Pu from the (proposed) AHWR fuel fabrication scrap solution. The extraction of Pu in the hexavalent state has been found to be distinctly more efficient than that in the tetravalent state. Distribution studies have been carried out by maintaining Pu as Pu(VI) employing AgO as the oxidant. Scrubbing at 5 M HNO 3 has been proposed to reduce the interference due to the co-extracted Th(IV). Quantitative stripping of the extracted Pu was achieved using hydroxyl ammonium-nitrate (HAN) as reductant. Ion exchange studies have been carried out for the final purification of Pu. It is proposed to employ the cation exchanger, Biorad AG 50X8 for the final purification of Pu from the stripped solution, keeping Pu as Pu(III). (orig.)

  6. REACT-Mod: a mathematical model for transient calculation of chemical reactions with U-Pu-Np-Tc in the aqueous nitric acid solution

    International Nuclear Information System (INIS)

    Tachimori, Shoichi; Kitamura, Tatsuaki.

    1996-10-01

    A computer code REACT-Mod which simulates various chemical reactions in an aqueous nitric acid solution involving uranium, plutonium, neptunium, technetium etc. e.g., redox, radiolytic and disproportionation reactions of 68, was developed based on the kinetics model. The numerical solution method adopted in the code are two, a kinetics model totally based on the rate law of which differential equations are solved by the modified Porsing method, and a two-step model based on both the rate law and equilibrium law. Only the former treats 27 radiolytic reactions. The latter is beneficially used to have a quick and approximate result by economical computation. The present report aims not only to explain the concept, chemical reactions treated and characteristics of the model but also to provide details of the program for users of the REACT-Mod code. (author)

  7. The AS-76 interlaboratory experiment on the alpha spectrometric determinaion of Pu-238. Part 3: Preparation and characterization of samples

    International Nuclear Information System (INIS)

    Bortels, G.; Broothaerts, J.; Bievre, P. de

    1980-01-01

    Four plutonium samples containing 0.2, 0.8, 1.6 and 0.9 atom % of 238 Pu have been prepared for the Interlaboratory Experiment AS-76. Of these three were input solutions from a reprocessing plant. The fourth sample was from a plutonium product solution. These samples have been characterized by two alpha spectrometry laboratories and two mass spectrometry laboratories to certify the ratio of alpha activities 238 Pu/( 239 Pu + 240 Pu) and the isotopic composition, respectively

  8. Microautoradiography in studies of Pu(V) sorption by trace and fracture minerals in tuff

    International Nuclear Information System (INIS)

    Vaniman, D.; Furlano, A.; Chipera, S.; Thompson, J.; Triay, I.

    1996-01-01

    Microautoradiography was used to evaluate the mineralogic basis of Pu(V) retention by tuffs from Yucca Mountain, Nevada. Altered orthopyroxenes and oxide minerals are associated with high Pu retention but are limited to specific stratigraphic horizons. A weaker but more general association of Pu with smectite occurs in most samples. Thin-sections that cross fractures allow comparative studies of Pu retention by fracture-lining versus matrix minerals. Using Ag metal in emulsions as a measure of underlying Pu concentration, electron-microprobe analysis can quantify Pu retention along fracture walls and provide mineral/mineral Pu retention factors. For smectite-lined microfractures in zeolitized tuff, the smectite/clinoptilolite Pu retention factor is >80

  9. Phytoextraction studies for removal of 239Pu using Vetiveria zizanoides plants

    International Nuclear Information System (INIS)

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

    2015-01-01

    The potential of Vetiveria zizanoides, a plant used for environmental conservation was tested for remediation of radionuclide plutonium ( 239 Pu). While the plant could remediate high levels of 239 Pu (65%) from solutions, remediation of radionuclides from soil was limited. Addition of chelating agents such as citric acid (CA) and diethylenetriaminepentaacetic acid (DTPA) enhanced phytoremediation of 239 Pu from soil. Translocation of 239 Pu to the shoot biomass showed an enhancement in the presence of chelating agents. The present studies have shown that V. zizanoides is a suitable candidate plant for remediation of 239 Pu and addition of DTPA enhanced translocation of radionuclide to shoot which may further lead to phytoextraction. (author)

  10. Two 238Pu inhalation incidents

    International Nuclear Information System (INIS)

    Fleming, R.R.; Hall, R.M.

    1978-06-01

    Two employees inhaled significant amounts of 238 Pu in separate unrelated contamination incidents in 1977. Both acute exposure incidents are described and the urine, feces, and in-vivo chest count data for each employee. Case B ( 238 PuNO 3 ) received 24 DTPA treatments beginning the day of the incident while, for medical reasons, Case A ( 238 PuO 2 ) received no therapy

  11. HPLC method for determination of Th, U and Pu in irradiated (Th,Pu)O{sub 2} using mandelic acid as an eluent

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pranaw; Paul, Sumana; Jaison, Perumpillil George; Telmore, Vijay Madhukar; Alamelu, Devanathan; Aggarwal, Suresh Kumar [Bhabha Atomic Research Centre, Mumbai (India). Fuel Chemistry Div.

    2014-07-01

    Studies for chromatographic separation of Th, U(VI) and Pu(IV) were carried out using mandelic acid as an eluent. The different chromatographic conditions like concentration of mandelic acid, pH of the mobile phase, presence of MeOH and effect of ion interaction reagent (IIR) were studied. The method was optimized for the separation of Th, U(VI) and Pu(IV). At pH<3.5 of mobile phase, Pu(IV) was more retained compared to U(VI) whereas at pH>3.5, reverse trend was observed. The optimized parameters were employed for the separation and determination of Th, U(VI) and Pu(IV) in a dissolved solution of irradiated (Th,Pu)O{sub 2}. Sample treatment was optimized to minimize loss of Pu and Th during chromatographic determination. Studies were carried out using two IIRs to understand the anomalous chromatographic behavior of Pu(IV). Retention behavior of different oxidation states of Pu viz. Pu(III), Pu(IV) and Pu(VI) was also studied in mandelic acid.

  12. PuLP/XtraPuLP : Partitioning Tools for Extreme-Scale Graphs

    Energy Technology Data Exchange (ETDEWEB)

    2017-09-21

    PuLP/XtraPulp is software for partitioning graphs from several real-world problems. Graphs occur in several places in real world from road networks, social networks and scientific simulations. For efficient parallel processing these graphs have to be partitioned (split) with respect to metrics such as computation and communication costs. Our software allows such partitioning for massive graphs.

  13. The unrivalled expertise for Pu recycling

    International Nuclear Information System (INIS)

    Fournier, W.; Pouilloux, M.

    1997-01-01

    Relying on the outstanding performances of the reprocessing facilities and the growing fabrication facilities, the in-reactor Pu recycling program in France and in other European countries is steadily implemented and has reached full-scale industrial operation. The RCR strategy -Reprocessing, Conditioning and Recycling- developed by COGEMA is now a well proven industrial reality. In 1997, plutonium recycling through MOX fuel is a mature industry, with successful operational experience and large-scale fabrication plants. In this field, COGEMA is the main actor, on operating simultaneously three complete multidesign fuel production plants: MELOX plant (in Marcoule), CADARACHE plant and DESSEL plant (in Belgium). Present MOX production capacity available to COGEMA fits 175 tHM per year and will be extended to reach about 325 tHM in the year 2000, that will represent 75% of the total MOX fabrication capacity in Europe. The industrial mastery and the high production level in MOX production assured by high technology processes confers COGEMA an unrivalled expertise for Pu recycling. This allows COGEMA to be a major actor in Pu-based fuels in the coming second nuclear era with advanced fuel cycles. The paper depicts the steps of the progressive advance of COGEMA to reach the Pu recycling expertise. (author)

  14. Investigation on U - O - Na, Pu - O - Na and U,Pu - O - Na phase diagrams

    International Nuclear Information System (INIS)

    Pillon, S.

    1989-03-01

    The thermochemical interaction between the nuclear fuel (uranium and plutonium mixed oxides) and the sodium has been investigated and particularly the three phase diagrams: U - O - Na; Pu - O - Na; U,Pu - O - Na. High temperature neutron diffraction, microcalorimetry and powder X-ray diffraction were used for the characterization of the compounds synthetized. This study allowed to complete the knowledge about each of these diagrams and to measure some physical and thermal properties on the compounds. The limits on the modelization of the fuel-sodium interaction are discussed from the results of the UO 2 - Na reaction [fr

  15. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2004-01-01

    The contamination of many DOE sites by Pu presents a long-term problem because of its long half-life (240,000 yrs) and the low drinking water standard ( -12 M). EDTA was co-disposed with radionuclides (e.g., Pu, 60 Co), formed strong complexes, and enhanced radionuclide transport at several DOE sites. Biodegradation of EDTA should decrease Pu mobility. One objective of this project was to determine the biodegradation of EDTA in the presence of PuEDTA complexes. The aqueous system investigated at pH 7 (10 -4 M EDTA and 10 -6 M Pu) contained predominantly Pu(OH) 2 EDTA 2- . The EDTA was degraded at a faster rate in the presence of Pu. As the total concentration of both EDTA and PuEDTA decreased (i.e., 10 -5 M EDTA and 10 -7 M PuEDTA), the presence of Pu decreased the biodegradation rate of the EDTA. It is currently unclear why the concentration of Pu directly affects the increase/decrease in rate of EDTA biodegradation. The soluble Pu concentration decreased, in agreement with thermodynamic predictions, as the EDTA was biodegraded, indicating that biodegradation of EDTA will decrease Pu mobility when the Pu is initially present as Pu(IV)EDTA. A second objective was to investigate how the presence of competing metals, commonly encountered in geologic media, will influence the speciation and biodegradation of Pu(IV)-EDTA. Studies on the solubilities of Fe(OH) 3 (s) and of Fe(OH) 3 (s) plus PuO 2 (am) in the presence of EDTA and as a function of pH showed that Fe(III) out competes the Pu(IV) for the EDTA complex, thereby showing that Pu(IV) will not form stable complexes with EDTA for enhanced transport of Pu in Fe(III) dominated subsurface systems. A third objective is to investigate the genes and enzymes involved in EDTA biodegradation. BNC1 can use EDTA and another synthetic chelating agent nitrilotriacetate (NTA) as sole carbon and nitrogen sources. The same catabolic enzymes are responsible for both EDTA and NTA degradation except that additional enzymes are

  16. Dominant lethal tests of male mice given 239Pu salt injections

    International Nuclear Information System (INIS)

    Luening, K.G.; Froelen, H.; Nilsson, A.

    1976-01-01

    To study the possible genetic effects of 239 Pu manifesting in dominant lethals, five test series (E1-E5) were performed. Males from an inbred CBA strain were given 239 Pu salt injections intravenously and mated weekly to 3 CBA females each for 12 to 24 weeks. Some interruptions in the mating scheme were made. For the first two test series (E1, E2) 239 Pu nitrate solution and 239 Pu citrate, used in E3-E5, were prepared. The solution was millipore filtered just prior to injection. Among a total of 10255 implants sired by males given Pu-nitrate in E1 and E2 no significant excess of intra-uterine death relative to 7216 control implants occurred. Test series E3-E5 with 60 males each, used three groups of 20, with one control group. In E3, 0.5 μCi and 0.1 μCi were given per male/group, respectively; in E4 and E5, 0.25 μCi and 0.05 μCi, respectively. The males given 0.5 μCi in E3 became successively sterile from the 7th week. The results in E3-E5 point in the same direction with significant excess of intra-uterine death in E3 and E5. In E4 the females from matings from the 9th, 14th and 16th week, and in E5 females from the 9th week, were allowed to litter to give F 1 offspring. Dominant lethal tests of F 1 males gave concordant results in all four samples, showing significantly excessive death in offspring to F 1 males whose fathers had received Pu. The excessive death was evenly distributed and did not indicate the presence of semisterile F 1 males. In tests of Pu-injected males and of F 1 males a remarkable excess of death in late stages of foetal development was observed. Such effects had never before been observed in this CBA strain in tests of extrinsic and intrinsic exposure to ionizing irradiation

  17. The absorption spectra of Pu(VI), -(V) and -(IV) produced electrochemically in carbonate-bicarbonate media

    International Nuclear Information System (INIS)

    Wester, D.W.; Sullivan, J.C.

    1983-01-01

    Absorption spectra in carbonate and bicarbonate media have been measured for various oxidation states of plutonium. The oxidation state of plutonium was adjusted electrochemically (Pu(VI)-V), Esub(f)=+0.11 V vs. SCE) to avoid contamination by redox reagents. In carbonate medium the spectra of Pu(VI) and Pu(V) showed marked differences from the spectra of the same oxidation state in acidic solutions. In bicarbonate the spectra of Pu(VI) and Pu(IV) also differed from the corresponding spectra in acidic media. Reduction to Pu(III) resulted in a precipitate in both carbonate and bicarbonate media. (author)

  18. Calculation on maximum accumulation of Pu-239 and Pu-241 from aqueous homogeneous reactor

    International Nuclear Information System (INIS)

    Ikhlas H Siregar; Frida Agung R; Suharyana; Azizul Khakim; Dahman Siregar

    2016-01-01

    Calculations on maximum accumulation of Pu-239 and Pu-241 using MCNPX computer code with UO_2(NO_3)_2 fuel solution enriched by 19.75% operating at temperature 80°C have been conducted. AHR design was simulated with cylindrical core having diameter of 63.4 cm and 122 cm high. From this geometry we found the reactor was critical with density 108 gr U/L of UO_2(NO_3)_2 solution. The result showed that multiplication factor (k_e_f_f) of AHR was 1.05284. Then the burn up calculations were done for various time intervals from 5 days until 285 years to analyze the result. From calculation, it was found out that the saturated concentration of Pu-239 was reached after 40-50 years of operation, producing 1.23 x 102 gr and the activity 7.645 Ci. While for operate time of AHR to produce Pu-241 should under 80 years with mass 21.7 gr and the activity 2.247 x 103 Ci. The accumulations of both isotopes are considered to be small, having low potential for misusing them for producing nuclear weapon. (author)

  19. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Bok, Frank [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    The time-dependent {sup 242}Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  20. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    International Nuclear Information System (INIS)

    Moll, Henry; Cherkouk, Andrea; Bok, Frank

    2017-01-01

    The time-dependent "2"4"2Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  1. Reactions of plutonium with aceto-hydroxamic acid in aqueous solutions: first results

    International Nuclear Information System (INIS)

    Butler, R.J.; Renshaw, J.C.; Collison, D.; Livens, F.R.

    2000-01-01

    Optical spectroscopy has been used to follow the complexation reactions of Pu(IV) and Pu(VI) with the acetohydroxamate (AHA - ) ligand. Significant reduction of Pu(IV) to Pu(III) occurs in the course of the experiment, although the experimental procedure has now been modified to suppress this and will allow Pu(IV)-AHA stability constants to be calculated. In the case of the Pu(VI)-AHA reaction, significant reduction occurs immediately, forming successively Pu(V), Pu(IV) and eventually Pu(III). This reaction was followed for 6 days, by which time Pu(VI) was quantitatively reduced to Pu(III). (authors)

  2. Reactions of plutonium with aceto-hydroxamic acid in aqueous solutions: first results

    Energy Technology Data Exchange (ETDEWEB)

    Butler, R.J.; Renshaw, J.C.; Collison, D.; Livens, F.R. [Manchester Univ. (United Kingdom). Dept. of Chemistry; Sinkov, S.; Choppin, G.R. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry; Taylor, R.J. [BNFL, Research and Technology, Sellafield, Seascale, Cumbria (United Kingdom)

    2000-07-01

    Optical spectroscopy has been used to follow the complexation reactions of Pu(IV) and Pu(VI) with the acetohydroxamate (AHA{sup -}) ligand. Significant reduction of Pu(IV) to Pu(III) occurs in the course of the experiment, although the experimental procedure has now been modified to suppress this and will allow Pu(IV)-AHA stability constants to be calculated. In the case of the Pu(VI)-AHA reaction, significant reduction occurs immediately, forming successively Pu(V), Pu(IV) and eventually Pu(III). This reaction was followed for 6 days, by which time Pu(VI) was quantitatively reduced to Pu(III). (authors)

  3. Plutonium(IV) peroxide formation in nitric medium and kinetics Pu(VI) reduction by hydrogen peroxide

    International Nuclear Information System (INIS)

    Maillard, C.; Adnet, J.M.

    2001-01-01

    Reduction of plutonium (VI) to Pu(IV) with hydrogen peroxide is a step in industrial processes used to purify plutonium nitrate solutions. This operation must be carefully controlled, in order to avoid any formation of the Pu(IV) peroxide green precipitate and to obtain exclusively Pu(IV). This led us to study the acidity and Pu and H 2 O 2 concentrations influences on the precipitate appearance and to perform a Pu(VI) reduction kinetic study on a wide range of acidities ([HNO 3 ]: 0.5 to 8 M), plutonium concentrations ([Pu(VI)]: 0.1 to 0.8 M) and [H 2 O 2 ]/[Pu(VI)] ratio (from 1 to 8). Thus, the domain of Pu(IV) peroxide formation and the reactional paths were established. With the exception of 0.5 M nitric acid medium, the kinetic curves show two distinct regims: the first one corresponds to an induction period where the Pu(VI) concentration doesn't change, the second corresponds to a linear decrease of Pu(VI). An increase of the temperature greatly accelerates the Pu(VI) reduction rate while [H 2 O 2 ]/[Pu(VI)] has almost no influence. The Pu(VI) total reduction time decreases when initial concentration of plutonium increases. By increasing nitric acid concentration from 0.5 M to 6 M, the total Pu(VI) reduction time decreases. This time increases when [HNO 3 ] varies from 6 M to 8 M. (orig.)

  4. Evaluation of nuclear data of 244Pu and 237Pu

    International Nuclear Information System (INIS)

    Nakagawa, Tsuneo; Konshin, V.A.

    1995-10-01

    The evaluation of nuclear data for 244 Pu and 237 Pu was made in the neutron energy region from 10 -5 eV to 20 MeV. For the both nuclides, the total, elastic and inelastic scattering, fission, capture, (n,2n) and (n,3n) reaction cross sections were evaluated on the basis of theoretical calculation. The resonance parameters were given for 244 Pu. The angular and energy distributions of secondary neutrons were also estimated for the both nuclides. The results were compiled in the ENDF-5 format and will be adopted in JENDL Actinoid File. (author)

  5. The use of ultrafiltration for the clean-up of alkaline Pu containing effluents

    International Nuclear Information System (INIS)

    Biddle, P.; Gutman, R.G.

    1983-07-01

    Ultrafiltration has been used to clean up low level Pu solutions at high pH. The decontamination factors achieved were greater than 1000 and were significantly higher than those attained by sedimentation or centrifugation. The results confirmed the findings of earlier work based on the use of Th as a simulant for Pu. A preliminary flowsheet for the decontamination of Pu oxalate liquors is proposed. (author)

  6. Comparative analysis of Pu spread resistance of chemico-technological (out of pile) complexes of electronuclear molten salt and heavy water blanket facilities for transmutation

    International Nuclear Information System (INIS)

    Volk, V.I.; Vakhrushin, A.Yu.; Gorbunov, V.F.; Kushnikov, V.V.

    1997-01-01

    Technological processes used for radiochemical reprocessing of molten salt and heavy water blankets of an electronuclear facility for Pu transmutation and Pu distribution in those processes are characterized. Below the major parameters are given that affect the resistance of the technological to Pu proliferation. Types of Pu migration: process losses, accident related losses, theft. Factors affecting migration are total inventory of Pu in a reprocessing complex, purity of Pu and its compounds, chemical condition of Pu, the feasibility of equipping technological processes with instruments of control. The comparative analysis carried out taking into account the above parameters established that the technological processes related to heavy water blanket reprocessing, specifically a homogeneous (solution) option, are much more resistant to Pu proliferation, including both Pu migration to the environment and the unsanctioned withdrawal of Pu from the technological process. 5 refs., 4 figs

  7. Status of 239Pu evaluations

    International Nuclear Information System (INIS)

    Kawano, Toshihiko; Talou, Patrick; Chadwick, Mark B.

    2014-01-01

    This paper summarises the current status of nuclear data evaluations for n+ 239 Pu. The nuclear data we address include fission, capture, scattering cross-sections, as well as the prompt fission neutron energy spectrum, which has large sensitivities to the criticality benchmark testing. The evaluated nuclear data files currently available for 239 Pu are compared, and the source of differences in the cross-sections are discussed. Some open questions on the statistical model calculations for deformed systems are also given. (authors)

  8. CHILD ALLOWANCE

    CERN Multimedia

    Human Resources Division

    2001-01-01

    HR Division wishes to clarify to members of the personnel that the allowance for a dependent child continues to be paid during all training courses ('stages'), apprenticeships, 'contrats de qualification', sandwich courses or other courses of similar nature. Any payment received for these training courses, including apprenticeships, is however deducted from the amount reimbursable as school fees. HR Division would also like to draw the attention of members of the personnel to the fact that any contract of employment will lead to the suppression of the child allowance and of the right to reimbursement of school fees.

  9. Calibration of the polycarbonate dosimeter for the microdosimetry of 239Pu alpha particles in bone

    International Nuclear Information System (INIS)

    Stillwagon, G.B.; Morgan, K.Z.

    1977-01-01

    There has been some criticisms of the maximum permissible organ burden (MPOB) in bone for 239 Pu in recent years. These criticisms allude to the relative dearth of experimental data available concerning the actual dose delivered to the endosteal face of osseous tissue by the 239 Pu alpha particle. A dosimeter recently developed has been recommended for application to this microdosimetry problem. The tissue equivalence of polycarbonate dosimeters would allow dose equivalent to be read directly from the foil rather than determining activity from emulsions, in which the alpha particle range is different than in tissue, then relating this activity measurement to absorbed dose by some calculations. Although this dosimeter has been calibrated to read dose equivalent for fast neutron dosimetry, the need exists to determine the factor to multiply by the number of 239 Pu alpha-induced tracks to obtain dose equivalent. This problem is being approached in the following manner. A device called the vacuum-sealed alpha-calibrator has been designed and constructed which will allow the handling of a standard 239 Pu solution obtained for this purpose. The calibrator will first be connected to surface barrier detectors which feed data into a multi-channel analyzer. The counts obtained under the alpha peaks at various heights above the source and the accumulated time are input into a computer program recently written to convert this data into dose rate in rems/unit time. Next the measurements are duplicated, this time using the polycarbonate dosimeter. The results will produce a factor relating the number of alpha-induced tracks to dose

  10. Adsorption of Pu(IV) Polymer onto 304L Stainless Steel

    International Nuclear Information System (INIS)

    Bronikowski, M.G.

    1999-01-01

    'The report, Technical Basis for Safe Operations with Pu-239 Polymer in NMS and S Operating Facilities (F and H Areas), (WSRC-TR-99-00008) was issued in an effort to upgrade the Authorization Basis (AB) for H Area facilities relative to nuclear criticality. At the time, insufficient data were found in the literature to quantify the adsorption of Pu polymer onto the surfaces of stainless steel tanks. Additional experimental or literature information on the adsorption of Pu(IV) polymer and its removal was deemed necessary to support the H Area AB. The results obtained are also applicable to processing in F Area facilities.Additional literature sources suggest that adsorption on the tank walls should not be a safety concern. The sources show that the amount of Pu polymer that adsorbs from a solution comes to a limiting amount in 5 to 7 days after which no additional Pu is adsorbed. Adsorption increases with Pu concentration and decreases with acid concentration. The adsorbed amounts are small varying from 0.5 mg/cm2 for a 0.5 g/l Pu / 0.5M HNO3 solution to 11 mg/cm2 for a 1-3 g/l Pu / 0.1M HNO3 solution. Additionally, acid concentrations greater than 0.1M will remove a percentage of adsorbed Pu.The experimental results have generally confirmed much of what has been reported in the literature. Specifically, adsorption onto stainless steel was found to increase with increased Pu concentration, and decreased acid concentration. The amount adsorbed was found to come to a limiting amount after 5 to 7 days. Pu adsorbed as polymer was found to be harder to remove than if it was adsorbed as Pu(IV). The amount of Pu adsorbed as polymer was found to be almost an order of magnitude more than that from a similar concentration Pu(IV) solution. Unlike the literature, only a slight increase in adsorption values was found when the steel surface was removed, dried, and replaced in the Pu solution. The amount of Pu as polymer which would adsorb onto the surface of a 14,000L tank was

  11. Radiative capture on $^{242}$Pu for MOX fuel reactors

    CERN Multimedia

    The use of MOX fuel (mixed-oxide fuel made of UO$_{2}$ and PuO$_{2}$) in nuclear reactors allows substituting a large fraction of the enriched Uranium by Plutonium reprocessed from spent fuel. Indeed around 66% of the plutonium from spent fuel is made of $^{239}$Pu and $^{241}$Pu, which are fissile in thermal reactors. A typical reactor of this type uses a fuel with 7% reprocessed Pu and 93% depleted U, thus profiting from both the spent fuel and the remaining $^{238}$U following the $^{235}$U enrichment. With the use of such new fuel compositions rich in Pu the better knowledge of the capture and fission cross sections of the Pu isotopes becomes very important. This is clearly stated in the recent OECD NEA’s “High Priority Request List” and in the WPEC-26 “Uncertainty and target accuracy assessment for innovative systems using recent covariance data evaluations” report. In particular, a new series of cross section evaluations have been recently carried out jointly by the European (JEFF) and United ...

  12. Pu-erh Tea Inhibits Tumor Cell Growth by Down-Regulating Mutant p53

    Science.gov (United States)

    Zhao, Lanjun; Jia, Shuting; Tang, Wenru; Sheng, Jun; Luo, Ying

    2011-01-01

    Pu-erh tea is a kind of fermented tea with the incorporation of microorganisms’ metabolites. Unlike green tea, the chemical characteristics and bioactivities of Pu-erh tea are still not well understood. Using water extracts of Pu-erh tea, we analyzed the tumor cell growth inhibition activities on several genetically engineered mouse tumor cell lines. We found that at the concentration that did not affect wild type mouse embryo fibroblasts (MEFs) growth, Pu-erh tea extracts could inhibit tumor cell growth by down-regulated S phase and cause G1 or G2 arrest. Further study showed that Pu-erh tea extracts down-regulated the expression of mutant p53 in tumor cells at the protein level as well as mRNA level. The same concentration of Pu-erh tea solution did not cause p53 stabilization or activation of its downstream pathways in wild type cells. We also found that Pu-erh tea treatment could slightly down-regulate both HSP70 and HSP90 protein levels in tumor cells. These data revealed the action of Pu-erh tea on tumor cells and provided the possible mechanism for Pu-erh tea action, which explained its selectivity in inhibiting tumor cells without affecting wild type cells. Our data sheds light on the application of Pu-erh tea as an anti-tumor agent with low side effects. PMID:22174618

  13. Transuranium perrhenates: Np(IV), Pu(IV) and (III), Am (III)

    International Nuclear Information System (INIS)

    Silvestre, Jean-Paul; Freundlich, William; Pages, Monique

    1977-01-01

    Synthesis in aqueous solution and by solid state reactions, crystallographical characterization and study of the stability of some transuranium perrhenates: Asup(n+)(ReO 4 - )sub(n) (A=Np(IV), Pu(IV), Pu(III), Am(III) [fr

  14. Fabrication of gamma sources using the neutron-gamma reactions of 238Pu13C

    International Nuclear Information System (INIS)

    Solinhac, I.; Maillard, C.; Donnet, L.

    2004-01-01

    A production campaign for 238 Pu 13 C sources with gamma fluence ranging from 2500 to 4500 gamma/s/4π at 6.13 MeV was carried out in 2002 in Atalante. An experimental study was undertaken to prepare the 238 PuC mixture, which is the most delicate step. This procedure is described together with the other steps in the source fabrication process: purification of a plutonium oxide batch, preparation of a nitric solution of 238 Pu, measurement of the gamma fluence of the PuC mixture before and after insertion into each of the two stainless steel capsules that constitute a PuN 2 O package, welding of the second envelope followed by leak testing, final measurement of the gamma fluence of the sealed source. This PuC sources fabrication procedure is effective: all the sources include the required gamma activity with an uncertainty on the gamma fluence of less than 10%. (authors)

  15. Electrochemistry and Spectroelectrochemistry of the Pu (III/IV) and (IV/VI) Couples in Nitric Acid Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lines, Amanda M. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Adami, Susan R. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Casella, Amanda J. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Sinkov, Sergey I. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Lumetta, Gregg J. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352; Bryan, Samuel A. [Nuclear Chemistry and Engineering, Pacific Northwest National Laboratory, Richland WA 99352

    2017-09-20

    The solution chemistry of Pu in nitric acid is explored via electrochemistry and spectroelectrochemistry. By utilizing and comparing these techniques, an improved understanding of Pu behavior and its dependence on nitric acid concentration can be achieved. Here the Pu (III/IV) couple is characterized using cyclic voltammetry, square wave voltammetry, and a spectroelectrochemical Nernst step. Results indicate the formal reduction potential of the couple shifts negative with increasing acid concentration and reversible electrochemistry is no longer attainable above 6 M HNO3. Spectroelectrochemistry is also used to explore the irreversible oxidation of Pu(IV) to Pu(VI) and shine light on the mechanism and acid dependence of the redox reaction.

  16. Pb-210 and Pu-239,240 in nearshore Gulf of Mexico sediments

    International Nuclear Information System (INIS)

    Rotter, R.J.

    1985-05-01

    Pb-210, Ra-226, and Pu-239,240 activities were measured in nearshore Gulf of Mexico sediments. Sediment cores were collected from the Mississippi delta, and the western Gulf of Mexico shelf. Mississippi delta cores which exhibit significantly higher sedimentation rates show larger inventories of Pb-210. The measured Pu levels from the western shelf are lower than from the delta at comparable depths. In three of the western shelf cores, the observed Pu inventory is considerably less than predicted from atmospheric flux. Therefore, Pu is not being removed to the sediment, or is being released following deposition. A key difference between these isotopes is that Pu exists in a less particle-reactive state. The ratio of excess Pb-210 to Pu levels increases with water depth in the delta and the western shelf. Water depth acts as an integrator of depth-sensitive processes. Pu scavenging is more sensitive to these processes. A sub-surface Pu maximum has been observed. Excess Pb-210 and Pu levels correlate well with sedimentation rates. This suggests that particle flux is important in removal of Pb-210 and Pu to the sediment. The flux of Mn out of the sediment is correlated with inventory data, suggesting that redox cycling of Mn may play a role in increasing Pb-210 and Pu sediment inventories. It is unclear whether the effects of increased sedimentation rates and increased Mn fluxes can be evaluated independently. Mixing of surface sediment correlates with inventory data. Increased sediment mixing allows for additional scavenging of Pb-210 and Pu from overlying waters. Mixing of sediment at depths below the mixed surface layer may play a role in increasing sediment inventories of Pb-210 and Pu

  17. PU-ICE Summary Information.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    The Generator Knowledge Report for the Plutonium Isentropic Compression Experiment Containment Systems (GK Report) provides information for the Plutonium Isentropic Compression Experiment (Pu- ICE) program to support waste management and characterization efforts. Attachment 3-18 presents generator knowledge (GK) information specific to the eighteenth Pu-ICE conducted in August 2015, also known as ‘Shot 18 (Aug 2015) and Pu-ICE Z-2841 (1).’ Shot 18 (Aug 2015) was generated on August 28, 2015 (1). Calculations based on the isotopic content of Shot 18 (Aug 2015) and the measured mass of the containment system demonstrate the post-shot containment system is low-level waste (LLW). Therefore, this containment system will be managed at Sandia National Laboratory/New Mexico (SNL/NM) as LLW. Attachment 3-18 provides documentation of the TRU concentration and documents the concentration of any hazardous constituents.

  18. Studies on extraction behaviour of U (VI) and Pu (IV) by Aliquat-336 encapsulated in microporous polymer beads

    International Nuclear Information System (INIS)

    Parikh, K.J.; Kedari, C.S.; Pandit, S.S.; Tripathi, S.C.; Dwivedi, C.; Singh, K.K.; Kumar, M.; Bajaj, P.N.

    2009-01-01

    Aliquat-336 encapsulated microporous polymeric beads (AEPB) were prepared to investigate their applicability for the solid-liquid extraction Pu (IV) from nitric acid solutions. Batch equilibration studies on the extractions of U (VI) and Pu (IV) from aqueous solutions using AEPB have been carried out at different concentrations of nitric acid and sodium nitrate. Extraction of Pu (IV) increases with increasing concentration of nitrate ions in the aqueous phase where as extraction of U (VI) remains less than 5% for all the aqueous conditions studied. Polymeric beads appeared to be less stable at higher nitric acid concentrations as the extraction of Pu (IV) was found to be lowered above 4 M HNO 3 concentration. The maximum Pu (IV) uptake by AEPB was 0.84 μg per mg of beads. Pu (IV)from loaded polymer can be back extracted using dilute nitric acid or ascorbic acid solution. (author)

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

    Science.gov (United States)

    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. © 2013 Elsevier B.V. All rights reserved.

  20. Early retention of 237Pu + 239Pu in mature beagles

    International Nuclear Information System (INIS)

    Lloyd, R.D.; McFarland, S.S.; Atherton, D.R.; Bruenger, F.W.; Taylor, G.N.; Mays, C.W.

    1978-01-01

    Five mature beagles, ranging in age from 57 to 84 months, were injected intravenously with about 0.05-0.1 μCi/kg of 239 Pu(IV) citrate to which tracer amounts of the photon-emitter 237 Pu had been added. Plutonium retention in liver and in non-liver tissue (mainly skeleton) was measured periodically in the living dogs for nearly 4 months after injection by a combination of total-body and partial-body counting. All excreta were collected during the first 21 days and analysed for their Pu content. One dog was sacrificed at 14 days and another at 118 days for distribution studies. About 17% (14-20%) of the injected Pu was excreted in the urine and feces in the first 3 weeks, about the same as that excreted in a corresponding time by beagles injected as young adults (14%), but substantially more than beagles injected as juveniles (11%). In contrasts to juvenile beagles injected at 3 months of age, in which early retention was about 12% in liver and 68% in the skeleton, mature beagles retained about 30% in liver and 50% in the skeleton. Retention in young adult beagles injected at 17 months of age was similar to that of mature dogs. Relative distribution of skeletal plutonium among various bones was similar in the mature animals to that seen previously in young adults, but quite different from that of juveniles. A notable exception was the humerus for which there was no significant difference (P>0.2) in the % of retained skeletal Pu represented by the humerus among the juvenile, young adult and mature dogs. (author)

  1. Reaction of alkali nitrates with PuO2

    International Nuclear Information System (INIS)

    Yamashita, T.; Ohuchi, K.; Takahashi, K.; Fujino, T.

    1990-01-01

    Improvement of solubility of plutonium dioxide (PuO 2 ) in acid solution is important to establish the nuclear fuel reprocessing technique for uranium-plutonium mixed oxide fuels. If insoluble PuO 2 can be converted into any soluble plutonium compounds, problems arising from the fuel dissolution process will be reduced to a great extent. Alkali metal plutonates and alkaline-earth plutonates are known to have enhanced solubility in mineral acids. However, the reaction conditions to form such plutonates and characterization thereof are not well elucidated. Then the reactivity and reaction conditions to form lithium and sodium plutonates from their nitrates and PuO 2 were studied at temperatures between 500 and 900 degree C and alkali metal to plutonium atom ratios between 0.5 and 6 by means of thermogravimetry as well as X-ray diffraction technique. The reaction behavior of alkali plutonates will be discussed in comparison with corresponding alkali uranates

  2. LEAD SLOWING DOWN SPECTROSCOPY FOR DIRECT Pu MASS MEASUREMENTS

    International Nuclear Information System (INIS)

    Ressler, Jennifer J.; Smith, Leon E.; Anderson, Kevin K.

    2008-01-01

    The direct measurement of Pu in previously irradiated fuel assemblies is a recognized need in the international safeguards community. A suitable technology could support more timely and independent material control and accounting (MC and A) measurements at nuclear fuel storage areas, the head-end of reprocessing facilities, and at the product-end of recycled fuel fabrication. Lead slowing down spectroscopy (LSDS) may be a viable solution for directly measuring not only the mass of 239Pu in fuel assemblies, but also the masses of other fissile isotopes such as 235U and 241Pu. To assess the potential viability of LSDS, an LSDS spectrometer was modeled in MCNP5 and 'virtual assays' of nominal PWR assemblies ranging from 0 to 60 GWd/MTU burnup were completed. Signal extraction methods, including the incorporation of nonlinear fitting to account for self-shielding effects in strong resonance regions, are described. Quantitative estimates of Pu uncertainty are given for simplistic and more realistic fuel isotopic inventories calculated using ORIGEN. A discussion of additional signal-perturbing effects that will be addressed in future work, and potential signal extraction approaches that could improve Pu mass uncertainties, are also discussed

  3. The effects of preparation, shipment and ageing on the Pu elemental assay results of milligram-sized samples

    International Nuclear Information System (INIS)

    Berger, J.; Doubek, N.; Jammet, G.; Aigner, H.; Bagliano, G.; Donohue, D.; Kuhn, E.

    1994-02-01

    Specialized procedures have been implemented for the sampling of Pu-containing materials such as Pu nitrate, oxide or mixed oxide in States which have not yet approved type B(U) shipment containers for the air-shipment of gram-sized quantities of Pu. In such cases, it it necessary to prepare samples for shipment which contain only milligram quantities of Pu dried from solution in penicillin vials. Potential problems due to flaking-off during shipment could affect the recovery of Pu at the analytical laboratory. Therefore, a series of tests was performed with synthetic Pu nitrated, and mixed U, Pu nitrated samples to test the effectiveness of the evaporation and recovery procedures. Results of these tests as well as experience with actual inspection samples are presented, showing conclusively that the existing procedures are satisfactory. (author). 11 refs, 6 figs, 8 tabs

  4. Use of 236Pu and 242Pu as a radiochemical tracer for estimation of Pu in bioassay samples by fission track analysis

    International Nuclear Information System (INIS)

    Sawant, Pramilla D.; Prabhu, Supreetha P.; Kalsi, P.C.

    2008-01-01

    236 Pu and 242 Pu are routinely used as radiochemical yield monitors in India for bioassay monitoring of occupational workers by alpha spectrometry. Fission Track Analysis (FTA) is also being standardized for trace level determination of Pu in bioassay samples. The present study, reports the utility of 236 Pu and 242 Pu as radiochemical tracers in estimation of Pu in bioassay samples by FTA technique. The advantages of using 236 Pu tracer in FTA over 242 Pu as well as the interference caused due to presence of 241 Pu in the bioassay samples of occupational workers handling power reactor grade Pu is discussed. (author)

  5. Economical Production of Pu-238

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Howe; Douglas Crawford; Jorge Navarro; Terry Ring

    2013-02-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238. The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100 M to get to production levels. The Center for Space Nuclear Research has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. The new process will also produce dramatically less waste. Potentially, the front end costs could be provided by private industry such that the government only had to pay for the product produced. Under a NASA Phase I NIAC grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce at least 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. In addition, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  6. Pu Sorption, Desorption and Intrinsic Colloid Stability under Granitic Chemical Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Pihong [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dai, Zurong [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kersting, Annie B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-09-04

    This progress report (M4FT-14LL0807031) describes research conducted at LLNL as part of the Crystalline Repository effort within the UFD program. Part I describes the dissolution kinetics of intrinsic Pu colloids synthesized in an alkaline solution. Part II describes the morphology and dissolution characteristics of various forms of Pu oxides prepared over a range of solution and temperature conditions. Proposed FY15 activities are identified.

  7. Migration of plutonium from freshwater ecosystem at Hanford. [/sup 238/Pu, /sup 239/Pu, /sup 240/Pu

    Energy Technology Data Exchange (ETDEWEB)

    Emery, R. M.; Klopfer, D. C.; McShane, M. C.

    1977-09-01

    A reprocessing waste pond at Hanford has been inventoried to determine quantities of plutonium (Pu) that have been accumulated since its formation in 1944. Expressions of export were developed from these inventory data and from informed assumptions about the vectors which act to mobilize material containing Pu. This 14-acre pond provides a realistic illustration of the mobility of Pu in a lentic ecosystem. The ecological behavior of Pu in this pond is similar to that in other contaminated aquatic systems having widely differing limnological characteristics. Since its creation, this pond has received about one Ci of /sup 239/,/sup 240/Pu and /sup 238/Pu, most of which has been retained by its sediments. Submerged plants, mainly diatoms and Potamogeton, accumulate >95% of the Pu contained in biota. Emergent insects are the only direct biological route of export, mobilizing about 5 x 10/sup 3/ nCi of Pu annually, which is also the estimated maximum quantity of the Pu exported by waterfowl, birds and mammals collectively. There is no apparent significant export by wind, and it is not likely that Pu has migrated to the ground water below U-Pond via percolation. Although this pond has a rapid flushing rate, a eutrophic nutrient supply with a diverse biotic profile, and interacts with an active terrestrial environment, it appears to effectively bind Pu and prevent it from entering pathways to man and other life.

  8. Am-241 as a metabolic tracer for inhaled Pu nitrate in external chest counting

    International Nuclear Information System (INIS)

    Ishigure, Nobuhito; Nakano, Takashi; Enomoto, Hiroko

    2000-01-01

    The most difficult radionuclides to measure by extemal chest counting are the isotopes of plutonium (Pu). They are detected through weak emission of low energy L X-rays. The Pu treated in nuclear fuel cycle is usually accompanied with 241 Am produced from 241 Pu by β disintegration, which emits γ-rays of 60 keV with the emission rate of 0.36, being more penetrable than the L X-rays. The 241 Am could improve the detection limit of chest counting of Pu, if it being used as a metabolic tracer for Pu in lungs. It has already been shown that the 241 Am which would probably be embedded in a matrix of PuO 2 is cleared from the lungs at the same rate as the Pu for long time after intake (N. Ishigure, et al., Radiat, Prot. Dosim., 79, 133, 1998), which supports the validity of 241 Am as a tracer of inhaled Pu in external chest counting. In the present work another possible chemical form present in work places, Pu nitrate, has been investigated. The solution of Pu(NO 3 ) 4 was nebulized using a compressed-air operated nebulizer. The resultant droplets were passed through a tube with fresh air and conduced into a multi-port nose-only exposure chamber, which resulted in polydisperse aerosols of Pu(NO 3 ) 4 with 0.6 μm in AMAD. Young adult male Wistar rats, being 13 weeks old and weighing 230 g at the time of exposure were used. The exposed rats were periodically sacrificed and the radioactivity of 241 Am and 238/239/240 Pu in the autopsied lungs were measured by photon spectrometry with a NaI/CsI phoswich detector system. The activity ratio of 241 Am vs. Pu in lungs, 2.4% at the exposure, slowly decreased to 2.1% at 4 week and 2.0% at 24 weeks. However, from practical point of view, it could be concluded that 241 Am would be a valid metabolic tracer for inhaled Pu nitrate at least for half a year post inhalation, considering the detection limit for Pu in chest counting, which is much greater than the ALI of Pu and the large uncertainties due to the estimation of chest wall

  9. The solubility of {sup 242}PuO{sub 2} in the presence of aqueous Fe(II). The impact of precipitate preparation

    Energy Technology Data Exchange (ETDEWEB)

    Felmy, Andrew R.; Moore, Dean A.; Buck, Edgar; Kukkadapu, Ravi; Sweet, Lucas; Abrecht, David; Ilton, Eugene S. [Pacific Northwest National Laboratory, Richland, WA (United States); Conrados, Steven D. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2014-07-01

    The solubility of different forms of precipitated {sup 242}PuO{sub 2}(am) were examined in solutions containing aqueous Fe(II) over a range of pH values. The first series of {sup 242}PuO{sub 2}(am) suspensions were prepared from a {sup 242}Pu(IV) stock that had been treated with thenoyltrifluoroacetone (TTA) to remove the {sup 241}Am originating from the decay of {sup 241}Pu. These {sup 242}PuO{sub 2}(am) suspensions showed much higher solubilities at the same pH value and Fe(II) concentration than previous studies using {sup 239}PuO{sub 2}(am). X-ray absorption fine structure (XAFS) spectroscopy of the precipitates showed a substantially reduced Pu-Pu backscatter over that previously observed in {sup 239}PuO{sub 2}(am) precipitates, indicating that the {sup 242}PuO{sub 2}(am) precipitates purified using TTA lacked the long range order previously found in{sup 239}PuO{sub 2}(am) precipitates. The Pu(IV) stock solution was subsequently re-purified using an ion exchange resin and an additional series of {sup 242}PuO{sub 2}(am) precipitates prepared. These suspensions showed higher redox potentials and total aqueous Pu concentrations than the TTA purified stock solution. The higher redox potential and aqueous Pu concentrations were in general agreement with previous studies on {sup 242}PuO{sub 2}(am) precipitates, presumably due to the removal of possible organic compounds originally present in the TTA purified stock. {sup 242}PuO{sub 2}(am) suspensions prepared with both stock solutions showed almost identical solubilities in Fe(II) containing solutions even though the initial aqueous Pu concentrations before the addition of Fe(II) were orders of magnitude different. By examining the solubility of {sup 242}PuO{sub 2}(am) prepared from both stocks in this way we have essentially approached equilibrium from both the undersaturated and oversaturated conditions. The final aqueous Pu concentrations are predictable using a chemical equilibrium model which includes the

  10. Modeling of Pu(IV) extraction and HNO3 speciation in nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    De-Sio, S.

    2012-01-01

    The PUREX process is a solvent extraction method dedicated to the reprocessing of irradiated nuclear fuel in order to recover pure uranium and plutonium from aqueous solutions of concentrated nitric acid. The tri-n-butylphosphate (TBP) is used as the extractant in the organic phase. The aim of this thesis work was to improve the modeling of liquid-liquid extraction media in nuclear fuel reprocessing. First, Raman and 14 N NMR measurements, coupled with theoretical calculations based on simple solutions theory and BIMSA modeling, were performed in order to get a better understanding of nitric acid dissociation in binary and ternary solutions. Then, Pu(IV) speciation in TBP after extraction from low nitric acid concentrations was investigated by EXAFS and vis-NIR spectroscopies. We were able to show evidence of the extraction of Pu(IV) hydrolyzed species into the organic phase. A new structural study was conducted on An(VI)/TBP and An(IV)/TBP complexes by coupling EXAFS measurements with DFT calculations. Finally, extraction isotherms modeling was performed on the Pu(IV)/HNO 3 /H 2 O/TBP 30%/dodecane system (with Pu at tracer scale) by taking into account deviation from ideal behaviour in both organic and aqueous phases. The best modeling was obtained when considering three plutonium (IV) complexes in the organic phase: Pu(OH) 2 (NO 3 ) 2 (TBP) 2 , Pu(NO 3 ) 4 (TBP) 2 and Pu(NO 3 ) 4 (TBP) 3 . (author) [fr

  11. Simultaneous measurement of {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, and {sup 242}Pu by high resolution inductively coupled plasma mass spectrometer (HR ICP-MS) in marine sediments; Mesure des isotopes du plutonium des sediments marins par spectrometrie de masse a plasma couple inductivement haute resolution (HR ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Bruneau, F

    1999-07-01

    Transuranics elements are of particular interest in radioecological studies because of their radiotoxicity and their potential use to decipher source fingerprints and transport processes. The simultaneous measurement of {sup 239}Pu, {sup 240}Pu, {sup 241}Pu, and {sup 242}Pu in environmental samples requires a specific chemical procedure. This work deals with an analytical procedure which yields a very high grade of purification of Pu suitable for ultra low level detection by HR ICP-MS, from marine sediments. After the elimination of major elements (Fe, Al, Mg...) by a first chromatographic separation, a new device of purification by solvent extraction and concentration by a second chromatographic separation is used to obtain a concentrated and high purified solution of plutonium. The chemical procedure have been validated on IAEA certified sediment samples and on sediment samples collected in the roads of Cherbourg which had been previously analysed by other techniques (a spectrometry and thermo-ionisation mass spectrometer). (author)

  12. Electronic Correlation Strength of Pu

    DEFF Research Database (Denmark)

    Svane, A.; C. Albers, R.; E. Christensen, N.

    2013-01-01

    A new electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the GW approximation we have surprisingly...... found a "universal" scaling relationship, where the f-electron bandwidth reduction due to correlation effects is shown to depend only upon the local density approximation (LDA) bandwidth and is otherwise independent of crystal structure and lattice constant....

  13. Nitridation of U and Pu recovered in liquid Cd cathode by molten salt electrorefining of (U,Pu)N

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Takumi; Iwai, Takashi; Arai, Yasuo [Japan Atomic Energy Agency (Japan)

    2009-06-15

    Solid solutions of actinide mono-nitrides have been proposed as a candidate fuel of the accelerator-driven system (ADS) and Gen.IV-type fast reactors because the thermal conductivity and metal density are higher than those of actinide oxides and also they have high melting temperature. Pyrochemical process has several advantages over conventional wet process in treating of spent nitride fuel. One of the key technologies of the pyrochemical reprocessing of nitride fuel is the formation of the nitrides from actinides in the liquid Cd cathode. The nitridation-distillation combined method was developed and has been adopted to convert the actinides to the nitrides. In this method, the nitridation of actinides and the distillation of Cd occurred simultaneously by heating the actinide-Cd alloys in N{sub 2} gas stream. In the present study, the nitride formation behavior of U and Pu recovered in Cd cathode by molten salt electrorefining of (U,Pu)N was experimentally investigated. In addition, the nitride pellet was prepared form the powder obtained by the nitridation of U and Pu recovered in Cd cathode. (U,Pu)N (PuN = 80 mol %) was used as the starting material in the experiment. Molten salt electrorefining of (U,Pu)N pellet was carried out in the LiCl-KCl eutectic salt with 1.2 wt% PuCl{sub 3} and 0.3 wt% UCl{sub 3} of about 110 g at the constant anodic potential of -0.60 to -0.55 V vs. Ag/AgCl for about 9 hours at 773 K. After the electrorefining, about 42 % of U and Pu in the starting (U,Pu)N pellet was dissolved at the anode and recovered into the liquid Cd cathode. The recovered U-Pu-Cd alloy was heated in an alumina crucible at 973 K for 10 hours under N{sub 2} gas (99.999 %) stream (0.015 L/min). Fine black powder was recovered after heating the U-Pu-Cd alloy. The powder was identified as the single phase solid solution of (U,Pu)N by the XRD analysis. After milling in the agate mortar for 1 hour, the powder was compacted into green pellet under a pressure of about

  14. Assembly-level analysis of heterogeneous Th–Pu PWR fuel

    International Nuclear Information System (INIS)

    Zainuddin, Nurjuanis Zara; Parks, Geoffrey T.; Shwageraus, Eugene

    2017-01-01

    Highlights: • We directly compare homogeneous and heterogeneous Th–Pu fuel. • Examine whether there is an increase in Pu incineration in the latter. • Homogeneous fuel was able to achieve much higher Pu incineration. • In the heterogeneous case, U-233 breeding is faster (larger power fraction), thus decreasing incineration of Pu. - Abstract: This study compares homogeneous and heterogeneous thorium–plutonium (Th–Pu) fuel assemblies (with high Pu content – 20 wt%), and examines whether there is an increase in Pu incineration in the latter. A seed-blanket configuration based on the Radkowsky thorium reactor concept is used for the heterogeneous assembly. This separates the thorium blanket from the uranium seed, or in this case a plutonium seed. The seed supplies neutrons to the subcritical thorium blanket which encourages the in situ breeding and burning of "2"3"3U, allowing the fuel to stay critical for longer, extending burnup of the fuel. While past work on Th–Pu seed-blanket units shows superior Pu incineration compared to conventional U–Pu mixed oxide fuel, there is no literature to date that directly compares the performance of homogeneous and heterogeneous Th–Pu assembly configurations. Use of exactly the same fuel loading for both configurations allows the effects of spatial separation to be fully understood. It was found that the homogeneous fuel with and without burnable poisons was able to achieve much higher Pu incinerations than the heterogeneous fuel configurations, while still attaining a reasonably high discharge burnup. This is because in the heterogeneous cases, "2"3"3U breeding is faster, thereby contributing to a much larger fraction of total power produced by the assembly. In contrast, "2"3"3U build-up is slower in the homogeneous case and therefore Pu burning is greater. This "2"3"3U begins to contribute a significant fraction of power produced only towards the end of life, thus extending criticality, allowing more Pu to

  15. A 233U/236U/242Pu/244Pu spike for isotopic and isotope dilution analysis by mass spectrometry with internal calibration

    International Nuclear Information System (INIS)

    Stepanov, A.; Belyaev, B.; Buljanitsa, L.

    1989-11-01

    The Khlopin Radium Institute prepared on behalf of the IAEA a synthetic mixture of 233 U, 236 U, 242 Pu and 244 Pu isotopes. The isotopic composition and elemental concentration of uranium and plutonium were certified on the basis of analyses done by four laboratories of the IAEA Network, using mass spectrometry with internal standardization. The certified values for 233 U/ 236 U ratio and the 236 U chemical concentration have a coefficient of variation of 0.05%. The latter is fixed by the uncertainty in the 235 U/ 238 U ratio of NBS500 used as internal standard. The coefficients of variation of the 244 Pu/ 242 Pu ratio and the 242 Pu chemical concentration are respectively 0.10% and 0.16% and limited by the uncertainty in the 240 Pu/ 239 Pu ratio of NBS947. This four isotope mixture was used as an internal standard as well as a spike, to analyze 30 batches of LWR spent fuel solutions. The repeatability of the mass spectrometric measurements have a coefficient of variation of 0.025% for the uranium concentration, and of 0.039% for the plutonium concentration. The spiking and treatment errors had a coefficient of variation of 0.048%. (author). Refs, figs and tabs

  16. {sup 239}Pu and {sup 240}Pu inventories and {sup 240}Pu/{sup 239}Pu atom ratios in the equatorial Pacific Ocean water column

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi, E-mail: myamada@cc.hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Zheng, Jian [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)

    2012-07-15

    The {sup 239+240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios were determined by alpha spectrometry and inductively coupled plasma mass spectrometry for seawater samples from two stations, one at the equator and the other in the equatorial South Pacific. To better understand the fate of Pu isotopes, this study dealt with the contribution of the close-in fallout Pu from the Pacific Proving Grounds (PPG) in water columns of the Pacific Ocean. The {sup 239}Pu, {sup 240}Pu and {sup 239+240}Pu inventories over the depth interval 0-3000 m at the equator station were 10.4, 8.9 and 19.3 Bq m{sup -2}, respectively. Further, no noticeable difference was observed in {sup 239}Pu, {sup 240}Pu and {sup 239+240}Pu inventories over the depth interval 0-3000 m between the two stations. The total {sup 239+240}Pu inventories were significantly higher than the expected cumulative deposition density of global fallout. Water column {sup 239+240}Pu inventories measured in this study were lower than those reported for comparable stations in the Geochemical Ocean Sections Study, indicating that these inventories have been decreasing at average rates of 0.89 {+-} 0.07 and 0.16 {+-} 0.07 Bq m{sup -2} yr{sup -1} at the equator and equatorial South Pacific stations, respectively, from 1973 to 1990. The obtained {sup 240}Pu/{sup 239}Pu atom ratios were higher than the mean global fallout ratio of 0.18. These high atom ratios proved the existence of close-in tropospheric fallout Pu from the PPG in the Marshall Islands. The {sup 239+240}Pu inventories originating from the close-in fallout in the entire water column were estimated to be 11.1 Bq m{sup -2} at the equator station and 7.1 Bq m{sup -2} at the equatorial South Pacific Ocean station, and the relative percentages of close-in fallout Pu were 40% at the former and 34% at the latter. A significant amount of close-in fallout Pu originating from the PPG has been transported to deep layers below the 1000 m depth in the equatorial

  17. Physiological Sensing Now Open to the World: New Resources Are Allowing Us to Learn, Experiment, and Create Imaginative Solutions for Biomedical Applications.

    Science.gov (United States)

    da Silva, Hugo Placido

    2018-01-01

    With the advent of low-cost computing platforms, such as Arduino (http://www.arduino.cc) and Raspberry Pi (http://www.raspberrypi.org), it has become clear that lowering the cost barrier and shortening the learning curve, with the backing of a motivated community, would play a transformational role in the way people learn, experiment, and create imaginative solutions to outstanding problems that can benefit from embedded systems.

  18. Rapid determination of 239Pu in urine samples using molecular recognition technology product AnaLigRPu-02 gel

    International Nuclear Information System (INIS)

    Silvia Dulanska; Boris Remenec; Jan Bilohuscin; Miroslav Labaska; Bianka Horvathova; Andrej Matel

    2013-01-01

    This paper describes the use of IBC's AnaLig R Pu-02 molecular recognition technology product to effectively and selectively pre-concentrate, separate and recover plutonium from urine samples. This method uses two-stage column separations consisting of two different commercial products, Eichrom's Pre-filter Material and AnaLig R Pu-02 resin from IBC Advanced Technologies. By eliminating the co-precipitation techniques and the ashing steps to remove residual organics, the analysis time was reduced significantly. The method was successfully tested by adding known activities of reference solutions of 242 Pu and 239 Pu to urine samples. (author)

  19. Study of new U(VI) and Pu(VI) coprecipitation methods for the preparation of (U,Pu)O2

    International Nuclear Information System (INIS)

    Sanoit, J. de.

    1990-01-01

    Two U(VI) and Pu(VI) coprecipitation methods have been studied, for the definition of new processes to prepare (U,Pu)O 2 mixed oxides suitable for making MoX fuels or fast breeder reactor fuels. The first system is based on the coprecipitation of a new U(VI), Pu(VI) compound; ammonium uranoplutonate, where as a second system is related to the precipitation of uranyl plutonyl monocarbonate. Experimental conditions to optimize the precipitation and the filtration steps of these two systems have been determined. After calcination under reducing conditions, the mixed oxides obtained are characterized according to different techniques: granulometry, thermogravimetry, solubility in boiling HNO 3 solutions. The properties of such oxides are excellent. The possible processes for preparing (U, Pu)O 2 using these new routes are compared with those actually exploited [fr

  20. Studies on Pu(IV)/(III)-oxalate precipitation from nitric acid containing high concentration of calcium and fluoride ions

    International Nuclear Information System (INIS)

    Kalsi, P.K.; Pawar, S.M.; Ghadse, D.R.; Joshi, A.R.; Ramakrishna, V.V.; Vaidya, V.N.; Venugopal, V.

    2003-01-01

    Plutonium (IV)/(III) oxalate precipitation from nitric acid solution, containing large amount of calcium and fluoride ions was investigated. It was observed that direct precipitation of Pu (IV) oxalate from nitric acid containing large amount of calcium and fluoride ions did not give good decontamination of Pu from calcium and fluoride impurities. However, incorporation of hydroxide precipitation using ammonium hydroxide prior to Pu (IV) oxalate precipitation results into PuO 2 with much less calcium and fluoride impurities. Whereas, good decontamination from calcium and fluoride impurities could be obtained by employing Pu (III) oxalate precipitation directly from nitric acid containing large amount of calcium and fluoride ions. A method was also developed to recover Pu from the oxalate waste containing calcium and fluoride ions. (author)

  1. Stability constants important to the understanding of plutonium in environmental waters, hydroxy and carbonate complexation of PuO2+

    International Nuclear Information System (INIS)

    Bennett, D.A.; Lawrence Berkeley Lab., CA

    1990-01-01

    The formation constants for the reactions PuO 2 + + H 2 O = PuO 2 (OH) + H + and PuO 2 + + CO 3 2 = PuO 2 (CO 3 ) - were determined in aqueous sodium perchlorate solutions by laser-induced photoacoustic spectroscopy. The molar absorptivity of the PuO 2 + band at 569 nm decreased with increasing hydroxide concentration. Similarly, spectral changes occurred between 540 and 580 nm as the carbonate concentration was increased. The absorption data were analyzed by the non-linear least-squares program SQUAD to yield complexation constants. Using the specific ion interaction theory, both complexation constants were extrapolated to zero ionic strength. These thermodynamic complexation constants were combined with the oxidation-reduction potentials of Pu to obtain Eh versus pH diagrams. 120 refs., 35 figs., 12 tabs

  2. Anthropogenic Pu distribution in Tropical East Pacific

    International Nuclear Information System (INIS)

    Kinoshita, Norikazu; Sumi, Takahiro; Takimoto, Kiyotaka; Nagaoka, Mika; Yokoyama, Akihiko; Nakanishi, Takashi

    2011-01-01

    The geographical distribution of the anthropogenic radionuclides 238 Pu and 239+240 Pu in the Tropical East Pacific in 2003 was studied from the viewpoint of material migration. We measured the contents of Pu isotopes in seawater and in sediment from the sea bottom. The distributions of Pu isotopes, together with those of coexisting nitrate and phosphate species and dissolved oxygen, are discussed in relation to the potential temperature and potential density (sigma-θ). The Pu contents in sediment samples were compared with those in the seawater. Horizontal migration across the Equator from north to south was investigated at depths down to ∼ 800 m in the eastern Pacific. The Pu distribution at 0-400 m correlated well with the distribution of potential temperature. Maximum Pu levels were observed in the subsurface layer at 600-800 m, corresponding to the depth where sigma-θ ∼ 27.0. It is suggested that the Pu distribution depends on the structure of the water mass and the particular temperature and salinity. The water column/sediment column inventory ratio and the vertical distribution of Pu may reflect the efficiency of scavenging in the relevant water areas. Research Highlights: → Geographical distributions of Pu isotopes were investigated from viewpoint of material migration. → Horizontal migration from north to south was found at depths down to ∼800 m in the eastern Pacific. → Pu distribution at 0-400 m was correlated with water temperature. → The distribution at 600-800 m correlated with water mass structure. → Pu in seawater and sediment gave information about efficiency of scavenging.

  3. The controlled-potential coulometric determination of plutonium based upon cerium oxidation and the Pu022+/Pu4+ valency change

    International Nuclear Information System (INIS)

    Phillips, G.; Crossley, D.; Venkataramana, P.

    1977-09-01

    Conditions have been established enabling plutonium to be oxidised quantitatively to the hexavalent state in the working compartment of a controlled-potential coulometric cell using electrogenerated ceric ion or excess ceric nitrate. The excess ceric ion is reduced in situ electrochemically without reduction of the hexavalent plutonium. The plutonium is then determined controlled-potential coulometrically by reduction to Pu 3+ followed by oxidation to Pu 4+ . The first oxidation step is conducted in molar nitric acid solution containing sulphamic acid but the coulometric determination step is conducted in molar sulphuric acid solution. The results obtained in the coulometric determination step were less satisfactory following oxidation with electrogenerated ceric ion rather than with chemically added ceric nitrate. Using the recommended conditions, 6 mg quantities of plutonium can be determined with an accuracy of 100.06% and a precision of 0.12% (coefficient of variation). The behaviour of chromium, manganese and vanadium impurity is reported. (author)

  4. Migration behaviour of Pu released from Pu-doped glass in compacted bentonite

    International Nuclear Information System (INIS)

    Ashida, T.; Kohara, Y.; Yui, M.

    1994-01-01

    In order to investigate the coupled behavior of Pu release from the waste glass and transport in bentonite, a migration experiment with compacted sodium-type bentonite saturated with distilled water was carried out at room temperature, in which Pu-doped borosilicate glass was sandwiched. Under these conditions, leaching of Pu from the glass, diffusion and sorption of Pu in the compacted bentonite occur simultaneously. (orig.)

  5. The application of data derived from autoradiographic studies with 241Pu in the formulation of a bone dosimetric model for 239Pu

    International Nuclear Information System (INIS)

    Priest, N.D.; Hunt, B.W.

    1979-01-01

    Recently a dosimetric model for 239 Pu in bone has been published which in conjunction with the general ICRP dosimetric model for actinides is used to calculate annual limits of intake for 239 Pu. This model allows for the burial of plutonium in bone, for the recycling of plutonium within the skeleton and for the retention of plutonium in the bone marrow. The model was based upon published descriptions of the distribution and redistribution patterns of plutonium in bone and on evidence obtained from autoradiographic studies of bone from animals injected with 241 Pu. The experiments with 241 Pu demonstrated the initial uptake of plutonium by bone surfaces. As a result of the growth and drift processes much of this plutonium became either buried in the bone or was retained within macrophages in the bone marrow. (author)

  6. Shortened preoperative fasting time to allow oral rehydration solution clear liquid up to two hours before elective major surgery in adults

    International Nuclear Information System (INIS)

    Shah, J.N.; Maharjan, S.; Curung, R.

    2018-01-01

    To generate evidence of feasibility to allow clear liquid 2 hours before elective surgery. Study Design: Cross-sectional observational study. Place and Duration of Study: The Department of Surgery, Patan Hospital, Patan Academy of Health Sciences, Nepal, from October to December 2016. Methodology: One hundred consecutive adult elective major surgery patients of American Society of Anesthesiologist criteria 1 or 2 were enrolled. The protocol was discussed with patients, nurses, anesthetists and surgeons to allow 500 ml clear liquid (ORS) up to 0600 hours on the day of surgery to maintain minimum of 2 hours (h) nil per os (NPO) before surgery. Compliance, discomfort, nausea and vomiting were observed. Institutional review committee approved the study. Microsoft excel was used for descriptive analysis. Results: All 100 patients completed the protocol of shortened fasting time. Two patients had incomplete records and were excluded from analysis. Among the 98 patients analysed, age was 48 +-12.38 years with 74 females (75.51% of 98). There were 68 gastrointestinal, 20 urosurgery and 10 others surgeries. There was no discomfort, nausea or vomiting reported due to ORS 2-h before elective surgery. Conclusion: Preoperative clear liquid up to 2-h before elective surgery in adults is feasible and safe in our set-up to shorten the fasting time. (author)

  7. 239 240Pu in Lake Michigan: 1971 to 1978

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Nelson, D.M.; Orlandini, K.A.; Kucera, E.T.

    1978-01-01

    The plutonium concentration data presented previously have consisted primarily of results from studies of short-term variations, i.e., the annual plutonium cycle conducted at Lake Michigan station ANL-5, 12 km SW of Grand Haven, Michigan. In this report, mean annual concentrations of total plutonium in unfiltered water from far off-shore (> 30 km) stations for the period 1971 through 1977, and from station ANL-5 (1975 through 1978) are summarized to establish the long-term trend in plutonium concentration in Lake Michigan. The results presented show that the mean annual concentration in the water column is similar at ANL-5 and at offshore stations and has decreased at the rate of only 6% per year during the period 1972 through 1978. The nearly constant concentration indicates that steady-state equilibria exist between plutonium inputs to the lake and the loss of plutonium from the water column. Observations suggest the existence of an active redox cycle for Pu in Lake Michigan. In this cycle, Pu IV atoms in solution are continually taken up by particulate materials but may be oxidized within microzones of the particles such as freshly deposited manganese coatings and also in solution by agents such as dissolved oxygen. In turn, the concentration of Pu VI in solution may be limited by reaction with reducing constituents of the coloidal-sized fraction (or decomposer organisms such as bacteria or fungi, which might have been present after filtration) and with planktonic organisms in the environment to produce Pu IV and thus maintain the cycle

  8. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Xun, Luying; Bolton, Jr. Harvey

    2001-01-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation

  9. Development of the DGT technique for in-situ Pu speciation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cusnir, R.; Bochud, F.; Froidevaux, P. [Institute of Radiation Physics, Lausanne University Hospital, Rue du Grand-Pre 1, CH-1007 Lausanne (Switzerland); Steinmann, P. [Federal Office of Public Health, Swarzenburgstrasse 165, CH-3003 Bern (Switzerland)

    2014-07-01

    Toxic effects of artificial radionuclides are strongly dependent on the surrounding chemical environment which determines the bioavailability of contaminant species. Speciation of plutonium in the environment is of particular interest since it is a long-life actinide contributing to the dose exposure via ingestion with water and food in case of radioactive discharge. Furthermore, natural colloids present in waters, as main carriers of dissolved trace metals, can transport plutonium over significant distances from contaminated sites. The diffusive gradients in thin films (DGT) technique is an efficient instrument for passive sampling of trace metals. It allows for in-situ monitoring of mean concentrations of bioavailable contaminant species (1). A DGT sampler consists of two gel layers: a polyacrylamide hydrogel diffusion layer allowing to diffuse labile metal species to the second, binding layer, impregnated with ion-exchange resin. Resin elution and further analysis allow determining the amount of the bioavailable fraction of trace metals in the bulk solution, which can be calculated from the relationship: C{sub bulk}= (M x Δg)/(D x t x A) where M is the measured metal species inventory in the resin, Δg the thickness of the diffusion layer, D the diffusion coefficient of the species in the gel, t the time of deployment, A the diffusion area. To our knowledge, the DGT has not yet been applied for Pu speciation measurements and the D value is unknown. Here we propose the use of DGT to monitor the dissolved phase and labile complexes of plutonium in the aquatic environment. We have first measured the diffusion coefficient of plutonium in the hydrogel. Experiments were carried out in a diffusion cell (2) and with commercially available DGT samplers exposed in standardized solutions containing {sup 239}Pu at pico-molar concentrations. Both approaches give comparable D values in the range of 2.30 x 10{sup -6} - 2.45 x 10{sup -6} cm{sup 2} s{sup -1}. We then studied

  10. Determination of the stability constant for the Pu(IV)-dinitrato complex using UV-VIS spectrophotometry

    International Nuclear Information System (INIS)

    Smith, C.A.; Veirs, D.K.

    1994-01-01

    Efficiency of the anion exchange process for the separation of plutonium is critically dependent upon the formation of the specific Pu(IV) nitrate complexes. Previous work is ambiguous as to the identification of the principal Pu(IV)-nitrate species present in nitric acid solutions. In this work, the authors study the nitrate complexes within the inner coordination sphere of Pu(IV) using absorption spectroscopy (nitrates in the outer coordination sphere probably do not affect the Pu(IV) absorption spectrum). The authors show that the Pu(IV)-aquo and -dinitrato species are associated with major peaks in the absorption spectrum at 469 and 476 nm, respectively. Absorption data from solutions where the nitrate concentration is varied at constant ionic strength are used to calculate stability constants for the dinitrato species, β 2 . Calculation of the stability constant at zero ionic strength and ion interaction coefficients are discussed

  11. The removal of inhaled 239Pu from beagle dogs by bronchopulmonary lavage and chelation therapy

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Slauson, D.O.; Miglio, J.J.; Ruoff, L.; Mersch, S.; McClellan, R.O.

    1976-01-01

    The efficacy of bronchopulmonary lavage and chelatan therapy for removing 239 Pu from beagle dogs after inhalation of 239 Pu aerosols having different solubilities has been investigated. The four aerosols used were nebulized from a solution of 239 PuCl 4 and heat treated at temperatures of 325, 600, 900 and 1150 0 C. Groups of six beagle dogs were exposed to each of the aerosols. Subsequently, three dogs in each group were treated by lavage and intravenous injections of DTPA. The remaining three dogs in each group served as untreated controls. It was found that bronchopulmonary lavage treatment was effective in removing nearly half of the 239 Pu activity from the lung regardless of the aerosol production temperature. This early removal of 239 Pu activity resulted in a significant reduction in daily dose rate and therefore cumulative α dose to lung. The effectiveness of DTPA treatment depended on aerosol production temperature, and was effective in reducing accumulation of 239 Pu in liver and skeleton of the dogs that inhaled aerosols produced at 325 0 and 600 0 C by enhancing urinary excretion of 239 Pu. (U.K.)

  12. Towards a spectroscopic standard database for Pu in repository environments

    International Nuclear Information System (INIS)

    Amme, M.

    2005-01-01

    Full text of publication follows: The alteration behaviour of Pu in geological and technical environments is, although of crucial importance for example in final repository assessment procedures for high-level nuclear waste, not sufficiently investigated. Since Pu chemistry differs significantly from U behaviour (mostly due to the different stabilities of the +IV oxidation states of both elements), conclusions based on the uranium analogy cannot be extended to Pu chemistry in many cases. In order to examine precisely the alteration behaviour of Pu under repository storage conditions, customized tools for the spectroscopic identification of the element need to be developed. We are currently constructing systematically a database of Pu compounds and collect their spectra for this purpose. Pu compounds (with the element in the oxidation states +III, +IV, +V, and +VI) are synthesised, mostly by using hydrothermal synthesis techniques [1]. Compounds of high importance for repository studies are: Carbonates, (oxy)hydroxides, silicates, peroxides, and phosphates. The products are characterised by Scanning Electron Microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS), and X-Ray diffraction (XRD). Furthermore, vibrational spectra (Raman and IR) of the substances will be recorded. These will allow the unambiguous identification of chemically similar compounds, once the database is compiled: Although reported for a few cases with nuclear material only, the combined investigation of solids with Raman [2,3] and SEM-EDX [3] in a combined mode, especially when spatially resolving, holds great potential An investigation with accelerator-based XAS techniques is planned within the framework of the Excellence network Actinet 6. [1] Grigorev, M., Bessonov, A., Makarenkov, V., Fedoseev, A., Model of the (PuO 2 ) 2 SiO 4 * 2H 2 O crystal structure, based on powder X-ray diffraction data, Radiochemistry, Vol. 45, No 3 (2003) 257-260. [2] M. Amme, B. Renker, B. Schmid, M. Feth, H

  13. Analysis of plutonium isotope ratios including 238Pu/239Pu in individual U-Pu mixed oxide particles by means of a combination of alpha spectrometry and ICP-MS.

    Science.gov (United States)

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

    2017-04-01

    Isotope ratio analysis of individual uranium-plutonium (U-Pu) mixed oxide particles contained within environmental samples taken from nuclear facilities is proving to be increasingly important in the field of nuclear safeguards. However, isobaric interferences, such as 238 U with 238 Pu and 241 Am with 241 Pu, make it difficult to determine plutonium isotope ratios in mass spectrometric measurements. In the present study, the isotope ratios of 238 Pu/ 239 Pu, 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of plutonium with UTEVA resins. Furthermore, 238 Pu/ 239 Pu isotope ratios were able to be calculated by using both the 238 Pu/( 239 Pu+ 240 Pu) activity ratios that had been measured through alpha spectrometry and the 240 Pu/ 239 Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including 238 Pu/ 239 Pu, in individual U-Pu mixed oxide particles. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. DFT and two-dimensional correlation analysis methods for evaluating the Pu3+–Pu4+ electronic transition of plutonium-doped zircon

    International Nuclear Information System (INIS)

    Bian, Liang; Dong, Fa-qin; Song, Mian-xin; Dong, Hai-liang; Li, Wei-Min; Duan, Tao; Xu, Jin-bao; Zhang, Xiao-yan

    2015-01-01

    Highlights: • Effect of Pu f-shell electron on the electronic property of zircon is calculated via DFT and 2D-CA techniques. • Reasons of Pu f-shell electron influencing on electronic properties are systematically discussed. • Phase transitions are found at two point 2.8 mol% and 7.5 mol%. - Abstract: Understanding how plutonium (Pu) doping affects the crystalline zircon structure is very important for risk management. However, so far, there have been only a very limited number of reports of the quantitative simulation of the effects of the Pu charge and concentration on the phase transition. In this study, we used density functional theory (DFT), virtual crystal approximation (VCA), and two-dimensional correlation analysis (2D-CA) techniques to calculate the origins of the structural and electronic transitions of Zr 1−c Pu c SiO 4 over a wide range of Pu doping concentrations (c = 0–10 mol%). The calculations indicated that the low-angular-momentum Pu-f xy -shell electron excites an inner-shell O-2s 2 orbital to create an oxygen defect (V O-s ) below c = 2.8 mol%. This oxygen defect then captures a low-angular-momentum Zr-5p 6 5s 2 electron to form an sp hybrid orbital, which exhibits a stable phase structure. When c > 2.8 mol%, each accumulated V O-p defect captures a high-angular-momentum Zr-4d z electron and two Si-p z electrons to create delocalized Si 4+ → Si 2+ charge disproportionation. Therefore, we suggest that the optimal amount of Pu cannot exceed 7.5 mol% because of the formation of a mixture of ZrO 8 polyhedral and SiO 4 tetrahedral phases with the orientation (10-1). This study offers new perspective on the development of highly stable zircon-based solid solution materials

  15. Safety requirements for the Pu carriers

    International Nuclear Information System (INIS)

    Mishima, H.

    1993-01-01

    Ministry of Transport of Japan has now set about studying requirements for Pu carriers to ensure safety. It was first studied what the basic concept of safe carriage of Pu should be, and the basic ideas have been worked out. Next the requirements for the Pu carriers were studied based on the above. There are at present no international requirements of construction and equipment for the nuclear-material carriers, but MOT of Japan has so far required special construction and equipment for the nuclear-material carriers which carry a large amount of radioactive material, such as spent fuel or low level radioactive waste, corresponding to the level of the respective potential hazard. The requirements of construction and equipment of the Pu carriers have been established considering the difference in heat generation between Pu and spent fuel, physical protection, and so forth, in addition to the above basic concept. (J.P.N.)

  16. Preliminary tests on the Pu(IV)-polymers

    International Nuclear Information System (INIS)

    Cauchetier, P.; Guichard, C.

    1983-02-01

    It is possible to obtain polymeric species from acid solutions of plutonium by water dilution or slow neutralization. In those two processes the heating improves the polymerization. We describe the conditions of these compounds formation when steam injected in low-acid nitric solutions. The soluble Pu(IV)-polymers are not absorbed by cation-exchangers. They have a well-characterized absorbance spectrum different from that of ionic species. They are stable even after the dilution in the same medium. Inversely, the change of medium including the acidification is able to induce the hydroxide precipitation [fr

  17. The uptake of Cs, Cl, I, Co, U and Pu by C-S-H, portlandite and ettringite

    International Nuclear Information System (INIS)

    Le Callonnec, C.; Richet, C.; Ayache, R.

    2000-01-01

    The aim of this work is to study the retention of Pu, Cs, Cl, U, Co and I onto the three phases of a cement paste: calcium silicate hydrates or C-S-H (Ca/Si=1.65), portlandite (Ca(OH) 2 ) and ettringite (Ca 6 Al 2 S 3 O 21 .32H 2 O). C-S-H of Ca/Si molar ratio of 1.65 and ettringite were prepared in suspension, while portlandite was provided by an industrial laboratory. The sorptive power for each ion was determined by a batch model at 20 degrees Celsius. The uptake of ions onto the phases has been obtained by introducing a very small volume of radioactive Cs, Co, Cl, I, U and Pu solution in each batch. Aliquots of solution were periodically removed for analysis. The results show that there are two kinds of ions whatever the solid phase: those which are poorly sorbed: Cs, Cl, I and Co, U and Pu which are strongly sorbed (by a factor 100 to 10000). Elsewhere, the comparison between the sorptive power of each phase reveals that C-S-H develops a significant sorption potential for pluri-valent ions (Pu, U, Co) as well as for Cl. The retention capacity of portlandite mainly towards pluri-valent cations is one or two orders of magnitude weaker than C-S-H capacity. Ettringite only plays a sorptive role relatively to Cs. However, iodine does not have a strong affinity for any solid at all. The data allow us to calculate a global sorption coefficient Kd of the cement paste for each ion. Assuming that the proportion of C-S-H, portlandite, ettringite is respectively 65%, 15% and 5% in a Portland cement, the global sorption coefficient is in good agreement with literature regarding on U, Cs, I and Cl. Cementitious materials appear to be an interesting chemical barrier that can limit the diffusion of pluri-valent cations. As C-S-H represent from 60% to 75% of the cement paste, this study leads to underline that C-S-H is mainly responsible for the retention capacity of cementitious materials specially towards U, Pu, Co, Cl although its sorption power is limited concerning

  18. 238Pu fuel form processes. Savannah River Laboratory monthly report

    International Nuclear Information System (INIS)

    1976-05-01

    Progress in the Savannah River 238 Pu fuel form program is summarized. Suspended solids observed in the technical-grade oxalic acid solution used in H-Area B-Line had no significant effect on particle size or morphology. A small but significant increase in product purity was noted with the use of reagent-grade oxalic acid. The density of hot-pressed LCHP pellets made from both problem and standardized feed decreased with longer milling times as was observed for multi-hundred watt (MHW) pellets. The LCHP pellets (greater than 90 percent theoretical density) generally cracked following final heat treatment. Cold-pressing studies indicate the anticipated pressure variation during cold pressing in the PuFF facility will have negligible effect on the density of MHW spheres. Construction of the plutonium experimental facility is 72 percent complete

  19. Sorption of 237Pu by the diatom Asterionella formosa

    International Nuclear Information System (INIS)

    Conway, H.L.; Wahlgren, M.A.; Peterson, N.; Nelson, D.M.

    1976-01-01

    Knowledge of the behavior of the man-made radionuclide plutonium within aquatic environments is of fundamental importance in assessing its potential hazards and ecological impact. The sorption of plutonium by phytoplankton and other algae is the dominant factor in the biological transport of plutonium in the aquatic environment, and it has been suggested that sorption by phytoplankton may be responsible for the seasonal loss of plutonium from the epilimnion of Lake Michigan. A unialgal diatom culture was spiked with 237 Pu tracer solution in an attempt to simulate the behavior of fallout plutonium observed in field studies. The results were encouraging in that the 237 Pu in the filtered lake water medium exhibited strongly anionic properties similar to fallout plutonium in Lake Michigan, with limited sorption on container walls. The purpose of the present study was to extend the investigations of the sorption of plutonium by phytoplankton in a controlled environment using continuous culture techniques

  20. Deposition of Pu-239 in human bodies

    International Nuclear Information System (INIS)

    Okabayashi, Hiroyuki

    1976-01-01

    It is known that plutonium produced by nuclear explosion tests has been widely dispersed on all over the earth and Pu-238 generated by the ''Accident of SNAP-9A'' in 1964 has been disposed into the atmosphere. These Pu are gradually falling down on the earth and taken into the human body through inhalation and ingestion. The measurements on the concentrations of Pu in bones and other various organs of Japanese population have been carried out. The results reveal that the concentrations of Pu in bones has a trend to be gradually increasing since 1962 and seems to be saturated at about 1970. The concentrations of Pu in bones sampled in 1971 are, in average, in the level of 4fCi per gram of wet samples and those in other organs (lung, liver, spleen, kidney, reproductive organs, etc.) sampled from 1963 to 1973 are in the level of 0.5-3.4 fCi per gram of wet tissues. Pu has been identified in the bones of fetus and infants and the averaged concentrations of placenta was 42.5 fCi. These may indicate that Pu would be transferred to the fetus through the placenta of mother. Some calculation has been attempted on the ratio of contributions through inhalation and ingestion to the body content of Pu, by using the formula for the scheme of metabolism of Pu compound in the body recommended by I.C.R.P. and this revealed that the contribution through inhalation route seemed to be greater than the other for the accumulation of Pu in the body. (auth.)

  1. Local atomic structure of α-Pu

    International Nuclear Information System (INIS)

    Espinosa, F. J.; Villella, P.; Lashley, J. C.; Conradson, S. D.; Cox, L. E.; Martinez, R.; Martinez, B.; Morales, L.; Terry, J.; Pereyra, R. A.

    2001-01-01

    The local atomic structure of α-Pu was investigated using x-ray absorption fine structure (XAFS) spectroscopy. XAFS spectra were obtained for a zone-refined α-Pu and the results were compared to 32-year-old and Ce-doped (0.34 at.%) samples. X-ray diffraction (XRD) patterns were also measured for the zone-refined and 32-year-old materials. The extent of the Bragg peaks showed that amorphization of the 32-year-old sample had not occurred despite the prolonged exposure to self-radiation. Analogous to metastable δ-Pu alloys, the local atomic structure around Pu for the zone-refined material shows the possible presence of noncrystallographic Pu-Pu distances. Conversely, the Ce and the 32-year-old sample show no evidence for such noncrystallographic distances. Disorder in the Pu local environment was found to be impurity dependent. The Ce-doped sample presented a larger Pu-Pu nearest neighbor disorder than the aged sample, although the total amount of Am, U, and He impurities was actually higher in the aged sample. The local environment around U and Ce impurities is consistent with these elements being in substitutional lattice sites. In addition, U and Ce do not introduce significant lattice distortion to their nearest neighbors. This is consistent with disorder being more related to the perturbation of the coupling between the electronic and crystal structure, or the Peierls--Jahn-Teller distortion that generates the monoclinic α-Pu structure, and less to strain fields produced in the vicinity of the impurities

  2. A multi-radionuclide approach to evaluate the suitability of 239+240Pu as soil erosion tracer

    International Nuclear Information System (INIS)

    Meusburger, Katrin; Mabit, Lionel; Ketterer, Michael; Park, Ji-Hyung; Sandor, Tarjan; Porto, Paolo; Alewell, Christine

    2016-01-01

    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 Pb ex . 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 (> 25 t ha −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 need for a

  3. Observations of surface-mediated reduction of Pu(VI) to Pu(IV) on hematite nanoparticles by ATR FT-IR

    Energy Technology Data Exchange (ETDEWEB)

    Emerson, Hilary P. [Florida International Univ., Applied Research Center, Miami, FL (United States); Powell, Brian A. [Clemson Univ., Dept. of Enviromental Engineering and Earth Sciences, Anderson, SC (United States)

    2015-07-01

    Previous studies have shown that mineral surfaces may facilitate the reduction of plutonium though the mechanisms of the reduction are still unknown. The objective of this study is to use batch sorption and attenuated total reflectance Fourier transform infrared spectroscopy experiments to observe the surface-mediated reduction of plutonium on hematite nanoparticles. These techniques allow for in situ measurement of reduction of plutonium with time and may lead to a better understanding of the mechanisms of surface mediated reduction of plutonium. For the first time, ATR FT-IR peaks for Pu(VI) sorbed to hematite are measured at ∝ 916 cm{sup -1}, respectively. The decrease in peak intensity with time provides a real-time, direct measurement of Pu(VI) reduction on the hematite surface. In this work pseudo first order rate constants estimated at the high loadings (22 mg{sub Pu}/g{sub hematite}, 1.34 x 10{sup -6} M{sub Pu}/m{sup 2}) for ATR FT-IR are approximately 10 x slower than at trace concentrations based on previous work. It is proposed that the reduced rate constant at higher Pu loadings occurs after the reduction capacity due to trace Fe(II) has been exhausted and is dependent on the oxidation of water and possibly electron shuttling based on the semiconducting nature of hematite. Therefore, the reduction rate at higher loadings is possibly due to the thermodynamic favorability of Pu(IV)-hydroxide complexes.

  4. Subcritical measurements with a cylindrical tank of Pu-U nitrate

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; Valentine, T.E.; King, W.T.

    1997-01-01

    This series of measurements with a mixed Pu-U nitrate solution (280 g Pu/liter, 180 g U/liter) in a 35.54-cm-diam cylindrical tank provides a wide variety of experimental data for subcritical configurations that can be used to verify calculational methods and nuclear data. The Pu contained 7.85 wt% 240 Pu and the uranium was natural uranium. The measurements performed were: inverse count rate, prompt neutron decay constants, inverse kinetics, and frequency analysis by the 252 Cf source driven method. These data are presented in sufficient detail that the results of the experiments can be calculated directly. For purposes of extrapolating to the delayed critical height the ratio of spectral densities was linear with height and thus provided the best estimate of critical height

  5. Simultaneous determination of U and Pu isotopes by alpha spectrometry

    International Nuclear Information System (INIS)

    Equillor, H.E.; Campos, J.M.

    2011-01-01

    Determination of actinides by alpha spectrometry is usually carried out after full separation of each of the components of the sample. The procedure presented in this paper permits U and Pu isotopes to be measured together allowing faster sample processing and measurement. The method consists in the extraction with tributyl phosphate of U and Pu isotopes from the rest of the matrix, followed by a cathodic electrodeposition to obtain alpha spectrometry suitable pieces. It can be applied to various environmental samples, such as water, filters and soil (about 0.5 g of solid sample for the described conditions). High-quality electroplated discs are essential for simultaneous processing, so a technique to achieve this requirement is also explained. (authors) [es

  6. Transuranic and tracer simulant resuspension. [/sup 238/Pu, /sup 239/Pu, /sup 240/Pu

    Energy Technology Data Exchange (ETDEWEB)

    Sehmel, G. A.

    1977-07-01

    Plutonium resuspension results are summarized for experiments conducted at Rocky Flats, onsite on the Hanford reservation, and for winds blowing from offsite onto the Hanford reservation near the Prosser barricade boundary. In each case, plutonium resuspension was shown by increased airborne plutonium concentrations as a function of either wind speed or as compared to fallout levels. All measured airborne concentrations were below maximum permissible concentrations (MPC). Both plutonium and cesium concentrations on airborne soil were normalized by the quantity of airborne soil sampled. Airborne radionuclide concentrations in ..mu..Ci/g were related to published values for radionuclide concentrations on surface soils. For this ratio of radionuclide concentration per gram on airborne soil divided by that for ground surface soil, there are eight orders of magnitude uncertainty from 10/sup -4/ to 10/sup 4/. Horizontal plutonium fluxes on airborne nonrespirable soils at all three sites were bracketed within the same three to four orders of magnitude from 10/sup -7/ to 10/sup -3/ ..mu..Ci/(m/sup 2/ day) for plutonium-239 and 10/sup -8/ to 10/sup -5/ ..mu..Ci/(m/sup 2/ day) for plutonium-238. These are the entire experimental base for nonrespirable airborne plutonium transport. Airborne respirable plutonium-239 concentrations increased with wind speed for a southeast wind direction coming from offsite near the Hanford reservation Prosser barricade. Airborne plutonium fluxes on nonrespirable particles had isotopic ratios, /sup 240/Pu//sup 239 +240/Pu, similar to weapons grade plutonium rather than fallout plutonium. Resuspension rates were summarized for controlled inert particle tracer simulant experiments. Wind resuspension rates for tracers increased with wind speed to about the fifth power.

  7. Chemical speciation of Pu in natural waters

    International Nuclear Information System (INIS)

    Nelson, D.M.; Larsen, R.P.; Penrose, W.R.

    1983-01-01

    The behavior of plutonium in natural waters is determined to a major degree by the chemical forms which are present. We have characterized the ambient Pu in a number of surface waters with regard to its oxidation state and association with natural colloidal organic carbon compounds using a combination of field measurements and laboratory experiments. Both of these factors are shown to have a profound effect on the adsorption of Pu to natural sediments, since both complexation with organic matter and oxidation compete with adsorption. The concentration of organic carbon in the water is the key variable influencing both oxidation state and organic binding. The adsorption process conforms to the laws applicable to a reversible equilibrium with values of the distribution coefficient, K/sub D/, measured in laboratory experiments being similar to those observed for ambient Pu. Experiments using natural waters and sediments in which the Pu concentration was varied show the forms present at typical ambient concentrations (10 -17 - 10 -14 M) are the same as those found at concentrations up to 10 -7 M. Moreover, the affinity for sediments did not change with concentration indicating the binding sites for Pu had not become saturated. Thus, the behavior observed for Pu at ultratrace concentrations should remain unchanged throughout this concentration range. The studies in this report all deal with Pu in exchangeable (and hence source independent) forms and should therefore reflect the behavior toward which the plutonium from any source will tend with time. 13 references, 7 figures, 10 tables

  8. Pu(IV) reduction with hydroxyurea and its application in U/Pu separation

    International Nuclear Information System (INIS)

    Zhu Zhaowu; He Jianyu; Zhang Zefu; Song Tianbao; Zhang Yu; Zheng Weifang

    2004-01-01

    The reduction of Pu(IV) with hydroxyurea (HU) in the mixed phase of 30% TBP/OK-HNO 3 system was studied. The study results show that HU can reduce Pu(IV) to Pu(III) and the reduction rate can be expressed as -dc(Pu(IV))/dt=kc(HU)c -3.2 (HNO 3 )c mix 2 (Pu(IV))c mix -1 (Pu(III)), where k is the rate constant, and k=(896 ± 59) mol 2.3 ·L -2.3 ·min -1 at 15 degree C. With HU serves as a reductant, 16 stages count-current cascade experiment was performed using centrifugal tube to simulate U/Pu separation in the 1B contactor of Purex process. The separation factor of Pu from U and the separation factor of U from Pu reach to 5.4 x 10 4 and 1.8 x 10 5 , respectively. The amount of Pu is about 11 μg in per kg U product. (authors)

  9. Aqueous Solution Chemistry of Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Clark, David L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-28

    Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.

  10. Investigations on the oxidation of nitric acid plutonium solutions with ozone

    International Nuclear Information System (INIS)

    Boehm, M.

    1983-01-01

    The reaction of ozone with nitric acid Pu solutions was studied as a function of reaction time, acid concentration and Pu concentration. Strong nitric acid Pu solutions are important in nuclear fuel element production and reprocessing. The Pu must be converted into hexavalent Pu before precipitation from the homogeneous solution together with uranium-IV, ammonia and CO 2 in the form of ammonium uranyl/plutonyl carbonate (AUPuC). Formation of a solid phase during ozonation was observed for the first time. The proneness to solidification increases with incrasing plutonium concentrations and with decreasing acid concentrations. If the formation of a solid phase during ozonation of nitric acid Pu solutions cannot be prevented, the PU-IV oxidation process described is unsuitable for industrial purposes as Pu solutions in industrial processes have much higher concentrations than the solutions used in the present investigation. (orig./EF) [de

  11. Corrosion of a Pu-doped zirconolite-rich ceramic

    International Nuclear Information System (INIS)

    Bakel, A.J.; Buck, E.C.; Wolf, S.F.; Chamberlain, D.B.; Bates, J.K.; Ebbinghaus, B.B.

    1997-01-01

    As part of a large Pu disposition program, a zirconolite-rich titanate ceramic is being developed at Lawrence Livermore National Laboratory (LLNL) as a possible immobilization material. This same material is being tested at Argonne National Laboratory (ANL). The goal of this study is to describe the corrosion behavior of this ceramic, particularly the release of Pu and Gd, using results from several static corrosion tests (MCC-1, PCT-A, and PCT-B). The release of relatively large amounts of Al, Ba, and Ca in short-term tests (3 day MCC-1 and 7 day PCT-A) indicates that these elements are released from grain boundaries or from highly soluble phases. Results from long-term (28, 98, and 182 day) PCT-B show that the releases of Al, Ba, and Ca decrease with time, the releases of U and Zr increase with time, and that the releases of Cs, Gd, Mo, and Pu remain fairly constant. Formation of alteration phases may lead to the decrease of Ba and Ca in leachate solutions. Due to the heterogeneous nature of the material, the formation of alteration phases, and the inherently low solubility of several elements, no element(s) could be recommended as good markers for the overall corrosion of this ceramic. Data show that, due to the complex nature of this material, the release of each element should be considered separately

  12. Interaction of Np(4) and Pu(4) with diisoamylphosphoric acid

    International Nuclear Information System (INIS)

    Sokhina, L.P.; Rovnyj, S.I.; Goncharuk, L.V.; Sladkova, M.V.; Tyumentseva, L.M.

    1988-01-01

    Interaction of neptunium (4) and plutonium (4) with diisoamylphosphoric acid (HD) in nitric acid solutions is investigated. It is ascertained that depending on mole ratio of HD and Np(Pu) in solution three types of compounds: Me (NO 3 ) 2 D 2 , Me(NO 3 ) 2 D 2 ·2HD and Me(NO 3 ) 2 D 2 ·4HD, are formed. The solubility of neptunium (plutonium) diisoamylphosphates in nitric acid, oxalate, carbonate and organic solutions, is determined. The possibility of the compound depositions in the extraction equipment should be taken into account in the process of spent fuel regeneration, when 30% HD solutions in n-paraffins are used as extractants

  13. Study of the number of neutrons produced by fission of {sup 239}Pu; Etude du nombre de neutrons produits par la fission de {sup 239}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Study of the number of neutrons produced by fission of {sup 239}Pu. The counting by coincidence of fissions and neutrons produced by these fissions allows the study of the variation of the mean number of neutrons emitted by {nu} fission. In the first chapter, it studied the variation of the mean number of neutrons emitted by {sup 239}Pu fission with the energy of the incident neutron. A description of the experiment is given: a spectrometer with a crystal of sodium chloride or beryllium (mounted on a goniometer) is used, a fission chamber containing 10 mg of {sup 239}Pu and the neutron detection system constituted of BF{sub 3} counters which are enriched in {sup 10}B. In the second part, the counting by coincidence of fissions and neutrons produced by the same fission and received by two different groups of counters allow the determination of a relationship between the root mean square and the average of neutron number produced by fission. The variation of the mean number of neutrons emitted by fission of {sup 239}Pu is studied when we change from a thermal spectra of neutrons to a fission spectra of incident neutrons. Finally, when separating in two different part the fission chamber, it is possible to measure the mean number of neutrons emitted from fission of two different sources. It compared the mean number of neutrons emitted by fission of {sup 239}Pu and {sup 233}U. (M.P.)

  14. Determination of the neutron-induced fission cross section of {sup 242}Pu; Bestimmung des neutroneninduzierten Spaltquerschnitts von {sup 242}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Koegler, Toni Joerg

    2016-04-26

    Neutron induced fission cross sections of actinides like the Pu-isotopes are of relevance for the development of nuclear transmutation technologies. For {sup 242}Pu, current uncertainties are of around 21%. Sensitivity studies show that the total uncertainty has to be reduced to below 5% to allow for reliable neutron physics simulations. This challenging task was performed at the neutron time-of-flight facility of the new German National Center for High Power Radiation Sources at HZDR, Dresden. Within the TRAKULA project, thin, large and homogeneous deposits of {sup 235}U and {sup 242}Pu have been produced successfully. Using two consecutively placed fission chambers allowed the determination of the neutron induced fission cross section of {sup 242}Pu relative to {sup 235}U. The areal density of the Plutonium targets was calculated using the measured spontaneous fission rate. Experimental results of the fast neutron induced fission of {sup 242}Pu acquired at nELBE will be presented and compared to recent experiments and evaluated data. Corrections addressing the neutron scattering are discussed by using results of different neutron transport simulations (Geant 4, MCNP 6 and FLUKA).

  15. Present status and future plans of the study for preparation of Pu reference materials

    International Nuclear Information System (INIS)

    Sumi, Mika; Kageyama, Tomio; Suzuki, Toru

    2007-01-01

    All accountancy analysis at the Plutonium Fuel Development Center of JAEA is performed by isotope dilution mass spectrometry with well-characterized standard materials. Though Pu reference materials has been supplied from foreign country, importing those Pu materials is gradually becoming more difficult and may be almost impossible to import them in future. Thus, in order to establish the capability and expertise for the preparation of Pu reference materials, JAEA has started collaborative work with NBL who has high skills for preparing and supplying nuclear reference materials for long periods. One of the targets of this collaboration is preparation of standard material for IDMS (LSD spike). MOX powder which has been stored in JAEA was dissolved and Purified to obtain Pu solution. A small portion of the Purified solution was transported to NBL for analysis. LSD spike will be prepared from this Pu solution and then validation analysis and performance test including stability test will be performed with NBL and JAEA. This report presents status and future plans for the collaboration work. (author)

  16. Isotope ratios of 240Pu/239Pu in soil samples from different areas

    International Nuclear Information System (INIS)

    Muramatsu, Yasuyuki; Yoshida, Satoshi; Yamazaki, Shinnosuke

    2003-01-01

    Plutonium concentrations and 240 Pu/ 239 Pu atom ratios in soil samples from Japan and other areas in the world (including IAEA standard reference materials) were determined by ICP-MS. The range of 240 Pu/ 239 Pu atom ratios observed in 21 Japanese soil samples was 0.155 - 0.194 and the average was 0.180 ± 0.011, which is comparable to the global fallout value. A low ratio of about 0.05, which is derived from Pu-bomb, was found in samples from Nishiyama (Nagasaki) and Mururoa Atoll (IAEA-368), while a high ratio of about 0.31 was found in a sample from Bikini Atoll (Marshall Islands). The ratio for Irish Sea sediment (IAEA-135) was 0.21, which was higher than the global fallout value, suggesting the influence by the contamination from the Sellafield facility. The 240 Pu/ 239 Pu atom ratios in soils from the Chernobyl area were determined, and the ratio was found to be very high (about 0.4), indicating the high burn-up grade of the reactor fuel. These results show that the 240 Pu/ 239 Pu ratio can be used as a finger print to identify the source of the contamination. (author)

  17. Determination of Pu in soil samples

    International Nuclear Information System (INIS)

    Torres C, C. O.; Hernandez M, H.; Romero G, E. T.; Vega C, H. R.

    2016-10-01

    The irreversible consequences of accidents occurring in nuclear plants and in nuclear fuel reprocessing sites are mainly the distribution of different radionuclides in different matrices such as the soil. The distribution in the superficial soil is related to the internal and external exposure to the radiation of the affected population. The internal contamination with radionuclides such as Pu is of great relevance to the nuclear forensic science, where is important to know the chemical and isotopic compositions of nuclear materials. The objective of this work is to optimize the radiochemical separation of plutonium (Pu) from soil samples and to determine their concentration. The soil samples were prepared using acid digestion assisted by microwave; purification of Pu was carried out with AG1X8 resin using ion exchange chromatography. Pu isotopes were measured using ICP-SFMS. In order to reduce the interference due to the presence of "2"3"8UH "+ in the samples, a solvent removal system (Apex) was used. In addition, the limit of detection and quantification of Pu was determined. It was found that the recovery efficiency of Pu in soil samples ranges from 70 to 93%. (Author)

  18. Preliminary results for complexation of Pu with humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Guczi, J.; Szabo, G. [National Research Inst. for Radiobiology and Radiohygi ene, Budapest, H-1775 (Hungary)]. e-mail: guczi@hp.osski.hu; Reiller, P. [CEA, CE Sac lay, Nuclear Energy Division/DPC/SERC, Laboratoire de Speciation des Radionuclei des et des Molecules, F-91191 Gif-sue-Yvette (France); Bulman, R.A. [Radiation Protection Division Division, Health Protection Agency, Chilton, Didcot (United Kingdom); Geckeis, H. [FZK - Inst. fuer Nukleare Entsorgung, Karlsruhe (Germany)

    2007-06-15

    Interaction of plutonium with humic substances has been investigated by a batch method use of the surface bound humic acid from perchlorate solutions at pH 4-6. By using these novel solid phases, complexing capacities and interaction constants are obtained. The complexing behavior of plutonium is analyzed. Pu(IV)-humate conditional stability constants have been evaluated from data obtained from these experiments by using non-linear regression of binding isotherms. The results have been interpreted in terms of complexes of 1:1 stoichiometry.

  19. Influence of initial lung deposit on absorption parameters of Pu and am: application to (U, Pu)O2 powder after inhalation in the baboon

    International Nuclear Information System (INIS)

    Rateau-matton, S.R.M.; Abram, M.C.; Rouit, E.; Grillon, G.; Legall, B.L.G.; Van Der Meeren, A.V.D.

    2006-01-01

    Full text of publication follows: In cases of contamination by inhalation, risk assessment would be performed taking into account recommendations of the International Commission of Radiological Protection (ICRP) Human Respiratory Tract Model (H.R.T.M.) described in Publication 66 (ICRP 66, 1994). The use of absorption parameter values specific to each component is recommended when available for dose calculation in order to provide a more realistic assessment of risk. The solubility of Pu and Am deposited in the respiratory tract after inhalation is a relevant parameter that can aid the identification of target organs. The aim of this study is to show the influence of the initial lung deposit (I.L.D.) on absorption parameters after inhalation of Mixed oxides (Mox) powder (7.14 % Pu w/w) in baboons. Daily urinary excretion of Pu/Am was measured for 3 months which allowed the estimation of the removal of the soluble fraction from lungs to blood and in particular a proportion of absorption parameters. Urinary excretion on 3 -month period were represented by biphasic curves which were directly reliable to physicochemical properties of compounds. Males baboon were exposed to I.L.D.: 40 to 860 kBq. Results obtained show that urinary excretions progress in the reverse order of I.L.D. Moreover, significant differences in the behaviour of Pu and Am were also observed in the target organs (liver and skeleton) and especially Am was more soluble than Pu for the compound studied. So, hypothesis of a more important dissolution of Am compare to Pu combines to a special affinity of Am for target organs seem to be involve. This result was very important in case of dismantling operation mainly in the usury of fuel since 241 Am is a filiation product of 241 Pu. In conclusion, this work contributes to support the usefulness of experimental data in radioprotection to estimate level of radiological exposition of worker. (authors)

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

    International Nuclear Information System (INIS)

    Johnson, S. G.

    1998-01-01

    This paper will describe the preparation and progress of the effort at Argonne National Laboratory-West to produce ceramic waste forms loaded with 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. 238 Pu possesses approximately 250 times the specific activity of 239 Pu and thus allows for a much shorter time frame to address the issue. In preparation for production of 238 Pu loaded waste forms 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 238 Pu loaded samples will be discussed

  1. Measurement of the ${240}$Pu(n,f) reaction cross-section

    CERN Multimedia

    Following proposal CERN-INTC-2010-042 / INTC-P-280 (“Measurement of the fission cross-section of $^{240}$Pu and $^{242}$Pu at CERN’s n_TOF Facility”), the parallel measurement of the $^{240}$Pu(n,f) and $^{242}$Pu(n,f) reaction cross-sections was carried out at n_TOF EAR-1. While the $^{242}$Pu measurement was successful, unexpected sample-induced damage to the detectors caused by the high α-activity of the 240Pu samples resulted in a deterioration of the detector performance over the data taking period of several months, which compromised the measurement. This obstacle can be eliminated by performing the measurement in EAR-2, where the higher neutron flux will allow collecting data in a much shorter time, thus preventing the degradation of the detectors. In addition to this obvious advantage, the measurement would also benefit from the stronger suppression of the sample-induced α-background, due to the shorter times-of-flight involved.

  2. NKS-Norcmass reference material for analysis of Pu-isotopes and 237Np by mass spectrometry

    International Nuclear Information System (INIS)

    Ross, P.; Nygren, U.; Appelblad, P.; Skipperud, L.; Sjoegren, A.

    2006-04-01

    The aim of the reference material in the Norcmass-project was to produce a low-level ( 239 Pu) sample of sufficient amount to allow individual laboratories to perform several tests without risk of using up the material. Although there are several reference materials available (eg IAEA) few have 239 Pu/ 240 Pu data and almost none have 237 Np/ 239 Pu-data. Those who have (eg IAEA-384) have very high concentrations and are not useful for testing analytical methods designed for low-level measurements where a large sample mass may be required. The reference material consist of the top 10cm of 2mm sieved soil pooled together from 12 different Danish locations collected during 2003. The Soil was blended and sieved through 0.6 and finally through a 0.4 mm sieve. A total amount of 17 kg soil was produced. Several aliquots of the material was subject to analysis by alpha spectrometry and ICP-MS. The material contain 239 + 240 Pu at a concentration of 0.24 ± 0.01 mBq/g and a 240 Pu/ 239 Pu atom ratio of 0.19 ± 0.006. The ratio 237 Np/ 239 Pu was determined to 0.32 ± 0.01. (au)

  3. Determination of 238Pu, 239+240Pu, 241Pu and 241Am in radioactive waste from IPEN reactor

    International Nuclear Information System (INIS)

    Geraldo, Bianca; Taddei, Maria Helena T.; Cheberle, Sandra M.; Ferreira, Marcelo T.

    2011-01-01

    Ion exchange resin is a common type of radioactive waste arising from treatment of coolant water of the main circuit of research and nuclear power reactors. This waste contains high concentrations of fission and activation products. The management of this waste includes its characterization in order to determine and quantify specific radionuclides including those known as difficult-to-measure radionuclides (RDM). The analysis of RDMs generally involves expensive and time-consuming complex radiochemical analysis for purification and separation of the radionuclides. The objective of this work is to show an easy methodology for quantifying plutonium and americium isotopes in spent ion exchange resin, used for purification of the cooling water of the IEA-R1 reactor located at the Nuclear and Energy Research Institute, IPEN-CNEN/SP. The resins were destroyed by acid digestion, followed by purification and separation of the Pu and Am isotopes with anionic and chromatographic resins. 238 Pu, 239 + 24 '0Pu, and 24 '1Am isotopes were analyzed in an alpha spectrometer equipped with surface barrier detectors. 241 Pu isotope was analyzed by liquid scintillation counting. Chemical recovery yield ranged from 73 to 98% for Pu and 77 to 98% for Am, demonstrating that the methodology is suitable for identification and quantification of the isotopes studied in spent resins. (author)

  4. A new fabrication route for SFR fuel using (U, Pu)O{sub 2} powder obtained by oxalic co-conversion

    Energy Technology Data Exchange (ETDEWEB)

    Vaudez, Stéphane, E-mail: stephane.vaudez@cea.fr [CEA, DEN, DEC, SPUA, Cadarache, F-13108 Saint-Paul-Lez-Durance (France); Belin, Renaud C.; Aufore, Laurence; Sornay, Philippe [CEA, DEN, DEC, SPUA, Cadarache, F-13108 Saint-Paul-Lez-Durance (France); Grandjean, Stéphane [CEA, DEN, DRCP, DIR, Marcoule, F-30207 Bagnols sur Cèze (France)

    2013-11-15

    The standard powder metallurgy preparation of SFR (Sodium Fast Reactor) oxide fuel involves UO{sub 2} and PuO{sub 2} co-milling. An alternative route, using a solid-solution of mixed oxide obtained by oxalic co-conversion as the starting material, is presented. It was used to manufacture nuclear fuels for the “COPIX” irradiation conducted in the Phenix SFR. Two processes using co-converted powders were tested to elaborate fuel pellets: (1) the Direct Process that consists in pressing and sintering the mixed oxide with the final Pu content and (2) the Dilution Process, which involves the dilution of a high Pu content mixed oxide with UO{sub 2}. After studying the structural and microstructural evolution with temperature of these innovative raw materials, the elaboration parameters were adjusted to obtain final pellets in accordance with the Phenix fuel specifications. This study demonstrates the feasibility of such new fabrication route at laboratory scale and, from a more fundamental prospect, allows a better understanding of the underlying phenomena involved during sintering.

  5. Separation and recovery of Cm from Cm-Pu mixed oxide samples containing Am impurity

    International Nuclear Information System (INIS)

    Hirokazu Hayashi; Hiromichi Hagiya; Mitsuo Akabori; Yasuji Morita; Kazuo Minato

    2013-01-01

    Curium was separated and recovered as an oxalate from a Cm-Pu mixed oxide which had been a 244 Cm oxide sample prepared more than 40 years ago and the ratio of 244 Cm to 240 Pu was estimated to 0.2:0.8. Radiochemical analyses of the solution prepared by dissolving the Cm-Pu mixed oxide in nitric acid revealed that the oxide contained about 1 at% of 243 Am impurity. To obtain high purity curium solution, plutonium and americium were removed from the solution by an anion exchange method and by chromatographic separation using tertiary pyridine resin embedded in silica beads with nitric acid/methanol mixed solution, respectively. Curium oxalate, a precursor compound of curium oxide, was prepared from the purified curium solution. 11.9 mg of Cm oxalate having some amounts of impurities, which are 243 Am (5.4 at%) and 240 Pu (0.3 at%) was obtained without Am removal procedure. Meanwhile, 12.0 mg of Cm oxalate (99.8 at% over actinides) was obtained with the procedure including Am removals. Both of the obtained Cm oxalate sample were supplied for the syntheses and measurements of the thermochemical properties of curium compounds. (author)

  6. Hydroxyurea reaction with HNO2 and Pu(III) stabilization

    International Nuclear Information System (INIS)

    Zhu Zhaowu; He Jianyu; Zhang Zefu; Zheng Weifang; Song Tianbao; Lin Min

    2004-01-01

    Reaction kinetics of hydroxyurea (HU) with HNO 2 in nitric acid solution is studied. The results show that the reaction rate follows the equation as: -dc(HNO 2 )/dt=k 0 c(HNO 2 )c 1.1 (HNO 3 ) c 0 (HU), where k 0 =(0.18±0.01)L 1.1 ·mol -1.1 ·s -1 at 10 degree C and c(HNO 2 )=5 mmol/L; the activation energy is deduced to be about 63 kJ/mol. The reaction appears zero order relative to HU. Kinetic study performed at various NaNO 3 solutions shows that salt ions have little effect on the reaction rate. Excess HU can stabilize Pu(III) well in nitric solutions

  7. Transmutation of 129I, 237Np, 238Pu, 239Pu, and 241Am using ...

    Indian Academy of Sciences (India)

    Results of transmutation studies of 129I, 237Np, 238Pu, 239Pu and 241Am are presented. Keywords. ... J Adam et al. Table 1. Samples properties for 0.7 and 1 GeV experiments. ..... If we suppose that this conclusion is true also for ratios in ...

  8. Improved MOX fuel calculations using new Pu-239, Am-241 and Pu-240 evaluations

    International Nuclear Information System (INIS)

    Noguere, G.; Bouland, O.; Bernard, D.; Leconte, P.; Blaise, P.; Peneliau, Y.; Vidal, J.F.; Saint Jean, C. de; Leal, L.; Schilleebeeckx, P.; Kopecky, S.; Lampoudis, C.

    2013-01-01

    Several studies based on the JEFF-3.1.1 nuclear data library show a systematic over-estimation of the critical keff for core configurations of MOX fuel assemblies. The present work investigates possible improvements of the C/E results by using new evaluations for Am-241, Pu-239 and Pu-240. The work reported in this paper demonstrates the performances of the new Am-241 evaluation based on capture and transmission data measured at the IRMM. For Pu-239, the new evaluation, established in the frame of the WPEC/SG-34, is able to explain a systematic discrepancy observed between different EOLE experiments. The combination of the Am-241 and Pu-239 evaluations demonstrates the necessity to improve the radiation width of the first resonance of Pu-240

  9. Worldwide data on fluxes of 239,240Pu, 238Pu to the oceans

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1987-04-01

    According to measurements (GEOSECS) the world's oceans contain approximately 16 PBq 239,240 Pu, of which one-fourth is in the Atlantic and three-fourths in the Pacific Ocean. The expected inventory (from nuclear weapons testing) in the world's oceans is 12 PBq 239,240 Pu including local fallout at the test sites. In the Irish Sea a local contamination of 0.3 PBq 239,240 Pu from the Sellafield reprocessing plant resides in the sediments. No other sources than fallout and reprocessing add significantly to the 239,240 Pu inventories in the oceans. The discrepancy between measurements and expectations are assumed to be due to an underestimate of the rainfall and dry fallout (seaspray) and thus of the Pu-deposition over the oceans, but may also to some degree be due to inadequate sampling

  10. Fermiology of PuCoGa{sub 5} and of related Pu-115 compounds

    Energy Technology Data Exchange (ETDEWEB)

    Oppeneer, P.M. [Department of Physics, Box 530, Uppsala University, S-751 21 Uppsala (Sweden)], E-mail: peter.oppeneer@fysik.uu.se; Shick, A.B. [Institute of Physics, Academy of Sciences of the Czech Republic, CZ-18221 Prague (Czech Republic); Rusz, J. [Department of Electronic Structures, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-121 16 Prague 2 (Czech Republic); Lebegue, S. [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, CNRS-Universite Henri Poincare, B.P. 239, F-54506 Vandoeuvre-les-Nancy (France); Eriksson, O. [Department of Physics, Box 530, Uppsala University, S-751 21 Uppsala (Sweden)

    2007-10-11

    We report computational investigations of the electronic structures of the superconducting Pu-compounds PuCoGa{sub 5} as well as of the non-superconducting compounds PuFeGa{sub 5} and PuNiGa{sub 5}. To capture the localization behavior of the Pu 5f electrons, we apply two computational approaches, which are both rooted in the density-functional theory: the local spin-density approximation (LSDA) and the around mean field (AMF) LSDA+U approach. The latter is applicable to moderately localized 5f electrons while the former is applicable to delocalized 5f electrons. Our LSDA calculations show that the Fermi surfaces of the three Pu-115 compounds are sensitive to the amount of band filling, i.e., the number of electrons of the 3d element. Precisely at the electron filling corresponding to PuCoGa{sub 5} the Fermi surface has a particularly two-dimensional shape. AMF-LSDA+U calculations (with a Coulomb U of about 3 eV and exchange J of 0.6 eV) lead to a non-magnetic ground state for PuCoGa{sub 5}, in which the 5f states are shifted to a higher binding energy, in better agreement with photoemission data. The Fermi surface of PuCoGa{sub 5} computed with the AMF-LSDA+U approach is nonetheless rather two-dimensional and similar to the LSDA Fermi surface. The AMF-LSDA+U approach with a Coulomb U of {approx}3 eV would thus predict an electronic structure for PuCoGa{sub 5} in accord with several experimental data.

  11. Separation of Pu from soil prior to determination by ICP-MS

    International Nuclear Information System (INIS)

    Nygren, U.; Baxter, D.C.

    2002-01-01

    In the determination of plutonium in environmental materials by ICP-MS, chemical separation is often needed to remove, e.g., heavy sample matrices and interference from UH + on m/z 239. This separation can be, and often is, performed in the same way as for alpha-spectrometric analysis. There are, however, somewhat different demands on separation for ICP-MS compared to alpha-spectrometry, but so far little has been published on the optimisation of separation procedures for plutonium determination by ICP-MS. This paper describes the development of a separation procedure especially suited for the determination of Pu by ICP-MS. Focus has been on parameters such as chemical yield of plutonium and decontamination from uranium, as well as time requirements and ease of performance. The separation of plutonium was performed using various resins, such as anion exchange resin and extraction chromatographic materials. The procedures were carried out on water spiked with 238 U and 240 Pu to concentrations of approximately 300 ppb and 50 ppt, respectively. The basic separation procedure was: 1. Adjustment of oxidation state for Pu 2. Loading on column 3. Rinsing using 4*5 free column volumes (FCVs) of load solution - if needed in combination with 1*5 FCVs of an other rinsing agent 4. Elution of Pu - if needed followed by evaporation and dissolution in a solution suitable for ICP-MS determination 5. Determination by high resolution ICP-MS The elution of plutonium was performed using various media, based on either reduction of Pu(IV) to Pu(III) or complex formation. The chemical yield of plutonium and the decontamination from uranium for various resin/elution combinations can be seen in Figs. 1 and 2. It was found that the most efficient separation procedure in terms of yield and uranium decontamination was the combination of two extraction chromatographic materials, UTEVA followed by TRU, and elution of Pu by 0.1 % 1-hydroxyethane-1,1-diphosphonic acid (HEDPA). In this procedure

  12. Redefining design criteria for Pu-238 gloveboxes

    International Nuclear Information System (INIS)

    Acosta, S.V.

    1998-01-01

    Enclosures for confinement of special nuclear materials (SNM) have evolved into the design of gloveboxes. During the early stages of glovebox technology, established practices and process operation requirements defined design criteria. Proven boxes that performed and met or exceeded process requirements in one group or area, often could not be duplicated in other areas or processes, and till achieve the same success. Changes in materials, fabrication and installation methods often only met immediate design criteria. Standardization of design criteria took a big step during creation of ''Special-Nuclear Materials R and D Laboratory Project, Glovebox standards''. The standards defined design criteria for every type of process equipment in its most general form. Los Alamos National Laboratory (LANL) then and now has had great success with Pu-238 processing. However with ever changing Environment Safety and Health (ES and H) requirements and Ta-55 Facility Configuration Management, current design criteria are forced to explore alternative methods of glovebox design fabrication and installation. Pu-238 fuel processing operations in the Power Source Technologies Group have pushed the limitations of current design criteria. More than half of Pu-238 gloveboxes are being retrofitted or replaced to perform the specific fuel process operations. Pu-238 glovebox design criteria are headed toward process designed single use glovebox and supporting line gloveboxes. Gloveboxes that will house equipment and processes will support TA-55 Pu-238 fuel processing needs into the next century and extend glovebox expected design life

  13. Co-electrospun blends of PU and PEG as potential biocompatible scaffolds for small-diameter vascular tissue engineering

    International Nuclear Information System (INIS)

    Wang, Heyun; Feng, Yakai; Fang, Zichen; Yuan, Wenjie; Khan, Musammir

    2012-01-01

    A small-diameter vascular graft (inner diameter 4 mm) was fabricated from polyurethane (PU) and poly(ethylene glycol) (PEG) solutions by blend electrospinning technology. The fiber diameter decreased from 1023 ± 185 nm to 394 ± 106 nm with the increasing content of PEG in electrospinning solutions. The hybrid PU/PEG scaffolds showed randomly nanofibrous morphology, high porosity and well-interconnected porous structure. The hydrophilicity of these scaffolds had been improved significantly with the increasing contents of PEG. The mechanical properties of electrospun hybrid PU/PEG scaffolds were obviously different from that of PU scaffold, which was caused by plasticizing or hardening effect imparted by PEG composition. Under hydrated state, the hybrid PU/PEG scaffolds demonstrated low mechanical performance due to the hydrophilic property of materials. Compared with dry PU/PEG scaffolds with the same content of PEG, the tensile strength and elastic modulus of hydrated PU/PEG scaffolds decreased significantly, while the elongation at break increased. The hybrid PU/PEG scaffolds demonstrated a lower possibility of thrombi formation than blank PU scaffold in platelet adhesion test. The hemolysis assay illustrated that all scaffolds could act as blood contacting materials. To investigate further in vitro cytocompatibility, HUVECs were seeded on the scaffolds and cultured over 14 days. The cells could attach and proliferate well on the hybrid scaffolds than blank PU scaffold, and form a cell monolayer fully covering on the PU/PEG (80/20) hybrid scaffold surface. The results demonstrated that the electrospun hybrid PU/PEG tubular scaffolds possessed the special capacity with excellent hemocompatibility while simultaneously supporting extensive endothelialization with the 20 and 30% content of PEG in hybrid scaffolds. - Highlights: ► We develop small-diameter vascular grafts made of PU and PEG by electrospinning. ► The hybrid scaffolds could suppress the platelet

  14. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    Science.gov (United States)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  15. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    International Nuclear Information System (INIS)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-01-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium

  16. Di-hydroxyurea-a Promising Reducing Reagent for the U/Pu split in the PUREX process

    Energy Technology Data Exchange (ETDEWEB)

    Taihong, Yan; Weifang, Zheng; Guoan, Ye; Yu, Zhang; Liang, Xian; Ying, Di; Xiaoyan, Bian [Department of Radiochemistry, China Institute of Atomic Energy - CIAE, Beijing 102413 (China)

    2009-06-15

    In the reprocessing of spent nuclear fuel by the Purex process, the separation of U and Pu is a major stage. This is commonly achieved by a redox process, in which a reducing agent (e.g. U(IV) or (FeII)) and a stabiliser (e.g. N{sub 2}H{sub 4} or NH{sub 2}SO{sub 3}H) are added to reduce extractable Pu{sup 4+} to un-extractable Pu{sup 3+}. The stabiliser prevents the nitrous acid catalysed re-oxidation of Pu(III) back to Pu(IV). One of the key objectives is to reduce both the number of solvent extraction cycles and the waste stream volumes [1]. One option for Advanced Purex flowsheets is to adopt a new salt-free reductant in the U/Pu split. Di-hydroxyurea(DHU)-a new Reducing reagent was synthesized with tri-associated solid phosgene (Bis(trichloromethyl)Carbonate) solved in dioxane and hydroxylamine hydrochloride solved in potassium acetate solution. The Reduction of Pu(IV) by DHU was investigated using UV-Vis spectrophotometer. The reduction back-extraction behavior of Pu(IV) in 30%TBP /OK was firstly investigated under conditions of different temperature, different concentration of DHU and HNO{sub 3} and various phase contract time respectively.The results showed that Pu(IV) in organic phase can be stripped rapidly to aqueous phase by DHU. Simulating the 1B contactor of the Purex process by DHU with nitric acid solution as the stripping agent,the separation factors of uranium/plutonium can reach 2.1 10{sup 4}. This indicates that DHU is a promising salt free agent for uranium/plutonium separation. (authors)

  17. Pu abundances, concentrations, and isotopics by x- and gamma-ray spectrometry assay techniques

    International Nuclear Information System (INIS)

    Camp, D.C.; Gunnink, R.; Ruhter, W.D.; Prindle, A.L.; Gomes, R.J.

    1986-01-01

    Two x- and gamma-ray systems were recently installed at-line in gloveboxes and will measure Pu solution concentrations from 5 to 105 g/L. These NDA technique, developed and refined over the past decade, are now used domestically and internationally for nuclear material process monitoring and accountability needs. In off- and at-line installations, they can measure solution concentrations to 0.2%. The K-XRFA systems use a transmission source to correct for solution density. The gamma-ray systems use peaks from 59- to 208-keV to determine solution concentrations and relative isotopics. A Pu check source monitors system stability. These two NDA techniques can be combined to form a new, NDA measurement methodology. With the instrument located outside of a glovebox, both relative Pu isotopics and absolute Pu abundances of a sample located inside a glovebox can be measured. The new technique works with either single or dual source excitation; the former for a detector 6 to 20 cm away with no geometric corrections needed; the latter requires geometric corrections or source movement if the sample cannot be measured at the calibration distance. 4 refs., 7 figs., 2 tabs

  18. A multi-radionuclide approach to evaluate the suitability of (239+240)Pu as soil erosion tracer.

    Science.gov (United States)

    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

  19. How well can we measure U and Pu on an interlaboratory basis?

    International Nuclear Information System (INIS)

    De Bievre, P.; Mayer, K.

    1991-01-01

    In measurements in general, and nuclear measurements in particular, it is no more a secret that the real state-of-the-practice (SOP) is frequently different from what is said at Conferences, written in books or claimed in meetings. Frequently the latter refer to the state-of-the-art (SOA) in research laboratories or to the ultimate possible only achievable in a few highly specialized institutes. Since it is important to have an objective basis to determine where the authors stand in SOP, CBNM is running a program to regularly determine the SOP on an interlaboratory basis for U and Pu element and isotope assay: REIMEP (Regular European Interlaboratory Measurement Evaluation Program). Participation is open to non-European countries. Well characterized samples are distributed to participants with characteristics undisclosed until participants' measurements have been received. Subsequently pictures are provided displaying (a) the interlaboratory spread, (b) the deviation of each participant to the carefully characterized reference value, (c) the participant's own estimate of his uncertainty allowing comparison with other participant's uncertainties and the uncertainty of the reference value. Thus the pictures act as instant photographs (snapshots) of the real SOP. The choice of the analytical method is up to the participant (titrimetry, coulometry, α-spectrometry, gas mass spectrometry, γ-spectrometry, thermionic mass spectrometry,...). The quoted uncertainty is also the participant's choice, but should be an accuracy defined as an uncertainty range claiming, for all practical purposes, to contain the true value. Up to now a number of rounds have been performed on various U and/or Pu containing materials such as pellets, powders, solutions, UF 6 . A number of graphs displaying the SOP will be shown

  20. Determination of the neutron-induced fission cross section of 242Pu

    International Nuclear Information System (INIS)

    Koegler, Toni Joerg

    2016-01-01

    Neutron induced fission cross sections of actinides like the Pu-isotopes are of relevance for the development of nuclear transmutation technologies. For 242 Pu, current uncertainties are of around 21%. Sensitivity studies show that the total uncertainty has to be reduced to below 5% to allow for reliable neutron physics simulations. This challenging task was performed at the neutron time-of-flight facility of the new German National Center for High Power Radiation Sources at HZDR, Dresden. Within the TRAKULA project, thin, large and homogeneous deposits of 235 U and 242 Pu have been produced successfully. Using two consecutively placed fission chambers allowed the determination of the neutron induced fission cross section of 242 Pu relative to 235 U. The areal density of the Plutonium targets was calculated using the measured spontaneous fission rate. Experimental results of the fast neutron induced fission of 242 Pu acquired at nELBE will be presented and compared to recent experiments and evaluated data. Corrections addressing the neutron scattering are discussed by using results of different neutron transport simulations (Geant 4, MCNP 6 and FLUKA).

  1. Study of the number of neutrons produced by fission of 239Pu

    International Nuclear Information System (INIS)

    Jacob, M.

    1958-01-01

    Study of the number of neutrons produced by fission of 239 Pu. The counting by coincidence of fissions and neutrons produced by these fissions allows the study of the variation of the mean number of neutrons emitted by ν fission. In the first chapter, it studied the variation of the mean number of neutrons emitted by 239 Pu fission with the energy of the incident neutron. A description of the experiment is given: a spectrometer with a crystal of sodium chloride or beryllium (mounted on a goniometer) is used, a fission chamber containing 10 mg of 239 Pu and the neutron detection system constituted of BF 3 counters which are enriched in 10 B. In the second part, the counting by coincidence of fissions and neutrons produced by the same fission and received by two different groups of counters allow the determination of a relationship between the root mean square and the average of neutron number produced by fission. The variation of the mean number of neutrons emitted by fission of 239 Pu is studied when we change from a thermal spectra of neutrons to a fission spectra of incident neutrons. Finally, when separating in two different part the fission chamber, it is possible to measure the mean number of neutrons emitted from fission of two different sources. It compared the mean number of neutrons emitted by fission of 239 Pu and 233 U. (M.P.)

  2. Kinetics of the high temperature oxygen exchange reaction on 238PuO2 powder

    International Nuclear Information System (INIS)

    Whiting, Christofer E.; Du, Miting; Felker, L. Kevin; Wham, Robert M.; Barklay, Chadwick D.; Kramer, Daniel P.

    2015-01-01

    Oxygen exchange reactions performed on PuO 2 suggest the reaction is influenced by at least three mechanisms: an internal chemical reaction, surface mobility of active species/defects, and surface exchange of gaseous oxygen with lattice oxygen. Activation energies for the surface mobility and internal chemical reaction are presented. Determining which mechanism is dominant appears to be a complex function including at least specific surface area and temperature. Thermal exposure may also impact the oxygen exchange reaction by causing reductions in the specific surface area of PuO 2 . Previous CeO 2 surrogate studies exhibit similar behavior, confirming that CeO 2 is a good qualitative surrogate for PuO 2 , in regards to the oxygen exchange reaction. Comparison of results presented here with previous work on the PuO 2 oxygen exchange reaction allows complexities in the previous work to be explained. These explanations allowed new conclusions to be drawn, many of which confirm the conclusions presented here. - Highlights: • PuO 2 Oxygen exchange kinetics can be influenced by at least 3 different mechanisms. • An internal chemical reaction controls the rate at high temperature and large SSA. • Surface mobility and surface exchange influence rate at lower temperatures and SSA. • Exchange temperatures may alter SSA and make data difficult to interpret.

  3. Disagregation of (U, Pu)O2 fuels in molten sodium nitrate and oxides system

    International Nuclear Information System (INIS)

    Chou, T.S.

    1976-01-01

    An oxidation process based on the use of an alkali-nitrate melt has been considered as a possible head end step for the reprocessing of FBR spent fuels. The total alkali solubility in the nitrate melt was examined. It is influenced by the temperature. At 500 degC the alkali solubility in the sodium nitrate melt is about 17 mol %. Examining solidified mixture of sodium and nitrate or sodium oxides and nitrite by X-ray diffraction has revealed five unknown lattices. NaNO 3 .xNa 2 O 2 is cubic (a=8.71A), NaNO 2 .xNa 2 O 2 is tetragonal (a=5.939A, c=9.997A), NaNO 2 .xNa 2 O is cubic (a=10.586A). The structure of NaNO 3 .xNa 2 O and NaNO 3 .xNaO 2 could not be determined. The solubility of barium and ruthenium was briefly investigated. The reaction (U,Pu)O 2 with the alkaline sodium nitrate melt proceeds along the grain boundaries of the solid solution. Two steps have been recognized. First (U,Pu)O 2 is oxidized to (U,Pu)Osub(2+x) and in a subsequent step (U,Pu)Osub(2+x) reacts with sodium peroxide to form (U,Pu) 2 O 5 .xNa 2 O 2 . Disaggregation efficiency is a function of temperature, alkali concentration and physical properties of the pellets. High temperature and low alkali concentration lead to high efficiency. The structure of the reaction products (U,Pu)O 2 with alkaline NaNO 3 melt was shown to depend mainly on the alkali concentration. As the alkali concentration is lower than 2 mole % (U,Pu) 2 O 5 . Na 2 O 2 is the dominate phase. (U,Pu) 2 O 5 .3Na 2 O 2 corresponds to 6 mole % and over 11 mole % alkali, (U,Pu) 2 O 5 .xNa 2 O 2 becomes the main product. The solubility of the fuel (U,Pu) in the alkali sodium nitrate melt increases with the alkali concentration up to 6000-8000 ppm for uranium and 1200-1700 ppm for plutonium at 500 degC with only 5 mole % alkali. As a result of high losses of fissile material in the salt bath molten salt process must regarded as uneligible for a general head end step in fuel reprocessing. Nevertheless its application can still be

  4. Localized 5f electrons in superconducting PuCoIn5: consequences for superconductivity in PuCoGa5

    International Nuclear Information System (INIS)

    Bauer, E D; Altarawneh, M M; Tobash, P H; Gofryk, K; Ayala-Valenzuela, O E; Mitchell, J N; McDonald, R D; Mielke, C H; Ronning, F; Scott, B L; Thompson, J D; Griveau, J-C; Colineau, E; Eloirdi, R; Caciuffo, R; Janka, O; Kauzlarich, S M

    2012-01-01

    The physical properties of the first In analog of the PuMGa 5 (M = Co, Rh) family of superconductors, PuCoIn 5 , are reported. With its unit cell volume being 28% larger than that of PuCoGa 5 , the characteristic spin-fluctuation energy scale of PuCoIn 5 is three to four times smaller than that of PuCoGa 5 , which suggests that the Pu 5f electrons are in a more localized state relative to PuCoGa 5 . This raises the possibility that the high superconducting transition temperature T c = 18.5 K of PuCoGa 5 stems from the proximity to a valence instability, while the superconductivity at T c = 2.5 K of PuCoIn 5 is mediated by antiferromagnetic spin fluctuations associated with a quantum critical point. (fast track communication)

  5. Suggestions for future Pu fuel cycle designs

    International Nuclear Information System (INIS)

    Serfontein, Dawid E.; Mulder, Eben J.; Reitsma, Frederik

    2013-01-01

    Recommended follow-up Pu Studies: • Verification of VSOP-A vs. VSOP 99/05, by comparison with MCNP. • DLOFC temperatures with Multi-group Tinte. • Redesign of the reactor: - Replace small concentrated Pu fuel kernels with large (500 μm diameter) diluted kernels to reduce burn-up. - Switch from the direct Brayton cycle to the indirect Rankine steam cycle to reduce fuel temperatures. - Add neutron poisons to the reflectors to suppress power and temperature peaks and to produce negative uniform temperature reactivity coefficients

  6. Fabrication of 12% 240Pu calorimetry standards

    International Nuclear Information System (INIS)

    Long, S.M.; Hildner, S.; Gutierrez, D.; Mills, C.; Garcia, W.; Gurule, C.

    1995-01-01

    Throughout the DOE complex, laboratories are performing calorimetric assays on items containing high burnup plutonium. These materials contain higher isotopic range and higher wattages than materials previously encountered in vault holdings. Currently, measurement control standards have been limited to utilizing 6% 240 Pu standards. The lower isotopic and wattage value standards do not complement the measurement of the higher burnup material. Participants of the Calorimetry Exchange (CALEX) Program have identified the need for new calorimetric assay standards with a higher wattage and isotopic range. This paper describes the fabrication and verification measurements of the new CALEX standard containing 12% 240 Pu oxide with a wattage of about 6 to 8 watts

  7. [Acupuncture messenger--Pu Xiang-cheng].

    Science.gov (United States)

    Du, Huai-bin; Liang, Fan-rong

    2011-06-01

    PU Xiang-cheng is the eminent acupuncture master in modern history of China. He studied diligently in early years and devoted his life to the cause of acupuncture practice and education in Chinese medicine. Combination of acupuncture and herbal medicine, coordination of acupuncture and moxibustion, unique application of acupoints, flexible combination of acupoints and focusing on needling techniques are the essence of his academic thoughts. The life of PU Xiang-cheng, the acupuncture master, and his major academic thoughts are described in this paper, so as to commemorate his contributions to acupuncture theory, practice and promotions.

  8. Multilevel resonance parameters of 241Pu

    International Nuclear Information System (INIS)

    Weston, L.W.; Todd, J.H.

    1978-01-01

    The data previously reported by the authors on the neutron fission and capture cross sections of 241 Pu were simultaneously fit with the Adler formalism to obtain multilevel resonance parameters. The neutron energy range of the fit was 0.01 to 100 eV. The 241 Pu cross sections in the resonance region of neutron energies are complex, and the Adler parameters present an efficient method of representing these cross sections, which are important for plutonium-fueled reactors. The parameters represent the data to an accuracy within the quoted experimental errors. 5 figures, 2 tables

  9. Pu sorption to activated conglomerate anaerobic bacteria

    International Nuclear Information System (INIS)

    Sasaki, Takayuki; Kudo, Akira

    2001-01-01

    The sorption of Pu to the anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after long dormant period was investigated. After 4 h at neutral pH, the distribution coefficient (K d ) between bacteria and aqueous phase at 308 and 278 K had around 10 3 to 10 4 . After over 5 days, however, the K d at only 308 K had increased to over 10 5 . Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. (author)

  10. Oxidation behaviour of plutonium rich (U, Pu)C and (U, Pu)O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sali, S.K., E-mail: sksali@barc.gov.in [Fuel Chemistry Division (India); Kulkarni, N.K.; Phatak, Rohan [Fuel Chemistry Division (India); Agarwal, Renu [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-10-15

    Oxidation behaviour of (U{sub 0.3}Pu{sub 0.7})C{sub 1.06} was investigated in air by heating samples up to 1073 K and 1273 K. Thermogravimetry (TG) of the samples and X-ray powder diffraction (XRD) of the intermediate products were used to understand the phenomenon taking place during this process. Theoretical calculations were carried out to understand the multiple phase changes taking place during oxidation of carbide. Theoretical results were validated by XRD analysis of the products obtained at different stages of oxidation. The final oxidized products were found to be a single FCC phase with O/M = 2.15 (M = U + Pu). Oxidation kinetic studies of (U{sub 0.3}Pu{sub 0.7})O{sub 2} and (U{sub 0.47}Pu{sub 0.53})O{sub 2} were carried out in dry air, using thermogravimetry, under non-isothermal conditions. The activation energy of oxidation was found to be 49 and 70 kJ/mol, respectively. Lattice parameter dependence on Pu/M and O/M of plutonium rich mixed oxide (MOX) was established using combined results of XRD and TG analysis of (U{sub 0.3}Pu{sub 0.7})O{sub 2+x} and (U{sub 0.47}Pu{sub 0.53})O{sub 2+x}.

  11. Presence of plutonium isotopes, {sup 239}Pu and {sup 240}Pu, in soils from Chile

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo, E., E-mail: echamizo@us.es [Centro Nacional de Aceleradores, Avda. Thomas Alba Edison, 7, 41092 Sevilla (Spain); Garcia-Leon, M., E-mail: manugar@us.es [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Avda. Reina Mercedes sn, 41012 Seville (Spain); Peruchena, J.I., E-mail: jiperuchena@gmail.com [Centro Nacional de Aceleradores, Avda. Thomas Alba Edison, 7, 41092 Sevilla (Spain); Cereceda, F., E-mail: francisco.cereceda@usm.cl [Laboratorio de Quimica Ambiental, Centro de Tecnologias Ambientales (CETAM), Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Vidal, V., E-mail: victor.vidal@usm.cl [Laboratorio de Quimica Ambiental, Centro de Tecnologias Ambientales (CETAM), Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Pinilla, E., E-mail: epinilla@unex.es [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas sn, 06071 Badajoz (Spain); Miro, C., E-mail: cmiro@unex.es [Departamento de Fisica Aplicada, Universidad de Extremadura, Avda. de la Universidad sn, 10071 Caceres (Spain)

    2011-12-15

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global {sup 239}Pu and {sup 240}Pu 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 {sup 239}Pu and {sup 240}Pu 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 Degree-Sign Southern latitude range, with {sup 240}Pu/{sup 239}Pu 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 Degree-Sign 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 {sup 239+240}Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global 239 Pu and 240 Pu 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 239 Pu and 240 Pu 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 240 Pu/ 239 Pu 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+240 Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

  13. Development of an analytical instrumentation for determining U, Np and Pu

    International Nuclear Information System (INIS)

    Wu Jizong; Guo Kuisheng; Liu Huanliang

    1995-01-01

    An analytical instrumentation for determining U, Np and Pu in the solution of reprocessing factory are made. The principle of the instrumentation is based on that of flow injection analysis and ion chromatography. The instrumentation is composed of controlling box and working box, the distance between the two boxes is 1.5 m. Important quantity of impurity is permitted. The determination limit is 1 mg/l. The relative standard deviation is better than 5%. The instrumentation can be used in 1AF, 1AP and other many controlling points for determining U, Np and Pu

  14. Quantitative Assay of Pu-239 and Pu-240 by Neutron Transmission Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, E

    1971-04-15

    A method for quantitative assay of 239Pu and 240Pu has been tested at the reactor R1 in Stockholm. The method makes use of a fast chopper to measure the neutron transmission through a sample around the main resonances of these two isotopes - at 0.296 eV in 239Pu and at 1.056 eV in 240Pu. The transmission data measured are then combined with the known resonance cross sections to give the content of the isotopes. The method is nondestructive, i.e., one can use fuel pins as samples, even highly irradiated ones. A time-of-flight spectrometer of moderate capacity, like our fast chopper, is sufficient as the resonances are located at low energy. Altogether five samples have been used in the tests of the method. The results have been compared with mass spectrometer values. This comparison came out quite well for 239Pu whereas the chopper results for 240Pu were more than 10 per cent higher than the mass spectrometer results. This large deviation might be due to errors in the resonance cross section for 240Pu used in the analysis of the transmission data from the chopper. The best possible accuracy for a 15-hour run with our equipment is +- 1 per cent for 239Pu and +- 2 per cent for 240Pu, obtained for thick samples - about 3 x 1020 atoms per cm2 for each isotope. The accuracy corresponds to 68 per cent confidence level and does not include any contribution from the uncertainty in the resonance cross section

  15. Evaluation of nuclear data of {sup 244}Pu and {sup 237}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tsuneo; Konshin, V.A. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-10-01

    The evaluation of nuclear data for {sup 244}Pu and {sup 237}Pu was made in the neutron energy region from 10{sup -5} eV to 20 MeV. For the both nuclides, the total, elastic and inelastic scattering, fission, capture, (n,2n) and (n,3n) reaction cross sections were evaluated on the basis of theoretical calculation. The resonance parameters were given for {sup 244}Pu. The angular and energy distributions of secondary neutrons were also estimated for the both nuclides. The results were compiled in the ENDF-5 format and will be adopted in JENDL Actinoid File. (author).

  16. Distribution of 238Pu and 239240Pu in aquatic macrophytes from a midwestern watershed

    International Nuclear Information System (INIS)

    Wayman, C.W.; Bartelt, G.E.; Alberts, J.J.

    1977-01-01

    Aquatic macrophytes were collected in the Great Miami River, Ohio, above and below Miamisburg and in the canal and ponds, near the Mound Laboratory, which contain sediments of a high activity (approximately 10 3 to 10 6 times) relative to the river sediments. Macrophytes collected in the river below Miamisburg have higher activities of 238 Pu than those collected from above the city. Macrophytes from the canal and ponds contain high specific activities of 238 Pu and 239 , 240 Pu with the exception of cattails grown in the ponds. Concentration factors are reported and discussed with reference to possible modes of plutonium accumulation and distribution within the plants

  17. Plutonium diffusion in advanced fuels (U,Pu)(C,O) and (U,Pu)(C,N)

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Matzke, H.

    1983-01-01

    The self-diffusion of 238 Pu was measured in an oxicarbide (U,Pu)(C,O) and a carbonitride (U,Pu) (C,N). The activation enthalpies were 447 and 347 kJ mol -1 , respectively. The carbonitrides were confirmed to fall into three classes: carbide-like compositions with less than 30% nitrogen in the metalloid lattice, nitride-like composition with more than 70% nitrogen and with reduced atomic mobilities, and carbonitrides with about 50% nitrogen showing an intermediate behavior. The oxicarbide showed diffusion coefficients slightly larger than those of pure carbides

  18. Methylbutylmalonamide as an extractant for U(VI), Pu(IV), and Am(III)

    International Nuclear Information System (INIS)

    Nair, G.M.; Prabhu, D.R.; Mahajan, G.R.

    1994-01-01

    The unsymmetrical diamide methylbutylmalonamide has been synthesized and used in the extraction of U(VI), Pu(IV), and Am(III) in benzene medium. The distribution ratio for three cations was found to increase with increasing aqueous nitric acid concentration. U(VI) and Pu(IV) were found to be extracted as disolvates while Am(III) as a trisolvate. The thermodynamic parameters determined by the temperature variation method showed the extraction reactions to be mainly enthalphy-controlled. Am(III) was found to be back-extracted with dilute nitric acid, while Pu(IV) by dilute nitric acid - hydrofluoric acid mixture and U(VI) by dilute sodium carbonate solution. (author) 6 refs.; 3 figs.; 2 tabs

  19. Exchange of Th, U and Pu on macroporous ion exchange resins

    International Nuclear Information System (INIS)

    Nadkarni, M.N.; Mayankutty, P.C.; Pillai, N.S.; Shinde, S.S.

    1977-01-01

    Absorption of Th, U and Pu on macroporous ion exchangers, Amberlyst 15 (cationic) and Amberlyst A-26 (anionic) were studied in nitric acid solutions and the results were found comparable with those on their microreticular counter parts, Dowex 50x8 and Dowex IX4. With a view to evalute the efficiency of Amberlyst A-26 for the final purification of plutonium from the purex process stream, detailed studies conducted to determine the breakthrough capacity of Pu(IV) from 7.2 M nitric acid, elution by 0.5 M nitric acid and the decontamination factors for uranium and zirconium-95. Because of its faster kinetics, Amberlyst A-26 exhibited a much more efficient elution of Pu(IV) by 0.5 M nitric acid than Dowex IX4. (author)

  20. Crystallography and magnetic properties of transuranium element oxygen compounds (Np, Pu and Am)

    International Nuclear Information System (INIS)

    Tabuteau, Alain.

    1981-05-01

    This paper includes: 1) The brief description of the experimental techniques used for analyzing very small quantities of solid radioactive compounds (differential thermal micro-analyses, diffraction of X rays, magnetic susceptibility and Moessbauer resonance). 2) The methods of synthesis of the ternary oxides of transuranic elements at oxidation degrees III (Pu 2 MoO 6 , Pu 2 WO 6 , Pu 2 (WO 4 ) 3 , Am 2 MoO 6 , Am 2 WO 6 , Am 2 (MoO 4 ) 3 and Am 2 (WO 4 ) 3 ) and at degree IV (Np(VO 3 ) 4 , Np(MoO 4 ) 2 , Np(WO 4 ) 2 and Pu(MoO 4 ) 2 ). The drawing up of liquid-solid balance diagrams enabled the field of stability of molybdate (or tungstate) systems of alkaline transuranic - mobybdates (or tungstates) to be clarified. 3) The study of the structural properties of the identified phases. These results taken as a whole made it possible to establish a ''comparative crystal - chemistry'' of the oxigenated phases of Np, Pu and Am with those of the thorium and uranium actinide elements and with the rare earths of adjacent ionic radius. 4) The Moessbauer resonance study of 237 Np in the solid solution Usub(1-x)Npsub(x)O 2 (0 [fr

  1. Designing of Multiphase Fly Ash/MWCNT/PU Composite Sheet Against Electromagnetic Environmental Pollution

    Science.gov (United States)

    Gujral, Parth; Varshney, Swati; Dhawan, S. K.

    2016-06-01

    Fly ash and multiwalled carbon nanotubes (MWCNT) reinforced multiphase polyurethane (PU) composite sheets have been fabricated by using a solution casting technique. Utilization of fly ash was the prime objective in order to reduce environmental pollution and to enhance the shielding properties of PU polymer. Our study proves that fly ash particles with MWCNTs in a PU matrix leads to novel hybrid high performance electromagnetic shielding interference material. Scanning electron microscopy confirms the existence of fly ash particles along with MWCNTs in a PU matrix. This multiphase composite shows total shielding effectiveness of 35.8 dB (>99.99% attenuation) in the Ku-band (12.4-18 GHz) frequency range. This is attributed to high dielectric losses of reinforcement present in the polymers matrix. The Nicolson-Ross-Weir algorithm has been applied to calculate the electromagnetic attributes and dielectric parameters of the PU samples by using scattering parameters ( S 11, S 22, S 12, S 21). The synthesized multiphase composites were further characterized by using x-ray diffraction, Fourier transform infrared spectroscopy, and thermo gravimetric analysis.

  2. Criticality safety study of Pu contaminated carbon waste stored in 100 L steel drums

    International Nuclear Information System (INIS)

    Anno, J.; Simonneau, M.

    1995-01-01

    The notion of the minimum critical areal density (D minca ) used to ensure the Criticality-Safety of poor solid waste is recalled with its deficiencies. D minca is assumed constant, independent of the fissile material concentration. This assumption is only true for unreflected mediums. Corrective factors are established. Furthermore, the usual norm of the Pu-H 2 O, which is 0.20 g/cm 2 , (concrete reflected) is greater than that for other mediums, such as Pu contaminated graphite waste (Pu-C), which is 0.036 g/cm 2 . D minca calculated on infinite slabs is confirmed by calculations on infinite planar multilayers arrays of 100 l cubical waste drums. Moreover, d minca increases linearly with the steel thickness of the drums' walls and goes up to 0.17 g/cm 2 for 0.105 cm of steel. The safety analysis on a real storage case takes into account the limited amount of Pu (100 g) and C (100 kg), the minimum thickness of 0.07 cm of drums' steel, their geometrical arrangement, the heterogeneity and size of contamination and the occurrence of neutronic poison (N and Cl) in the waste. Because of these parameters, the Keff are very less than 0.95 and the taken norm of 0.1 g/cm 2 for the Pu-C waste is fulfilled. Finally, it is demonstrated that the mixing of Pu-C waste drums and Pu-H 2 O wastes drums is allowed. (authors). 14 refs., 5 figs., 6 tabs

  3. DFT and two-dimensional correlation analysis methods for evaluating the Pu{sup 3+}–Pu{sup 4+} electronic transition of plutonium-doped zircon

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Liang, E-mail: bianliang@ms.xjb.ac.cn [Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, Xinjiang (China); Laboratory for Extreme Conditions Matter Properties, South West University of Science and Technology, Mianyang 621010, Sichuan (China); Dong, Fa-qin; Song, Mian-xin [Laboratory for Extreme Conditions Matter Properties, South West University of Science and Technology, Mianyang 621010, Sichuan (China); Dong, Hai-liang [Department of Geology and Environmental Earth Science, Miami University, Oxford, OH 45056 (United States); Li, Wei-Min [Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, Xinjiang (China); Duan, Tao; Xu, Jin-bao [Laboratory for Extreme Conditions Matter Properties, South West University of Science and Technology, Mianyang 621010, Sichuan (China); Zhang, Xiao-yan [Key Laboratory of Functional Materials and Devices for Special Environments, Chinese Academy of Sciences, Urumqi 830011, Xinjiang (China); Laboratory for Extreme Conditions Matter Properties, South West University of Science and Technology, Mianyang 621010, Sichuan (China)

    2015-08-30

    Highlights: • Effect of Pu f-shell electron on the electronic property of zircon is calculated via DFT and 2D-CA techniques. • Reasons of Pu f-shell electron influencing on electronic properties are systematically discussed. • Phase transitions are found at two point 2.8 mol% and 7.5 mol%. - Abstract: Understanding how plutonium (Pu) doping affects the crystalline zircon structure is very important for risk management. However, so far, there have been only a very limited number of reports of the quantitative simulation of the effects of the Pu charge and concentration on the phase transition. In this study, we used density functional theory (DFT), virtual crystal approximation (VCA), and two-dimensional correlation analysis (2D-CA) techniques to calculate the origins of the structural and electronic transitions of Zr{sub 1−c}Pu{sub c}SiO{sub 4} over a wide range of Pu doping concentrations (c = 0–10 mol%). The calculations indicated that the low-angular-momentum Pu-f{sub xy}-shell electron excites an inner-shell O-2s{sup 2} orbital to create an oxygen defect (V{sub O-s}) below c = 2.8 mol%. This oxygen defect then captures a low-angular-momentum Zr-5p{sup 6}5s{sup 2} electron to form an sp hybrid orbital, which exhibits a stable phase structure. When c > 2.8 mol%, each accumulated V{sub O-p} defect captures a high-angular-momentum Zr-4d{sub z} electron and two Si-p{sub z} electrons to create delocalized Si{sup 4+} → Si{sup 2+} charge disproportionation. Therefore, we suggest that the optimal amount of Pu cannot exceed 7.5 mol% because of the formation of a mixture of ZrO{sub 8} polyhedral and SiO{sub 4} tetrahedral phases with the orientation (10-1). This study offers new perspective on the development of highly stable zircon-based solid solution materials.

  4. Experimental Benchmarking of Pu Electronic Structure

    International Nuclear Information System (INIS)

    Tobin, J.G.; Moore, K.T.; Chung, B.W.; Wall, M.A.; Schwartz, A.J.; Ebbinghaus, B.B.; Butterfield, M.T.; Teslich, N.E. Jr.; Bliss, R.A.; Morton, S.A.; Yu, S.W.; Komesu, T.; Waddill, G.D.; van der Laan, G.; Kutepov, A.L.

    2008-01-01

    The standard method to determine the band structure of a condensed phase material is to (1) obtain a single crystal with a well defined surface and (2) map the bands with angle resolved photoelectron spectroscopy (occupied or valence bands) and inverse photoelectron spectroscopy (unoccupied or conduction bands). Unfortunately, in the case of Pu, the single crystals of Pu are either nonexistent, very small and/or having poorly defined surfaces. Furthermore, effects such as electron correlation and a large spin-orbit splitting in the 5f states have further complicated the situation. Thus, we have embarked upon the utilization of unorthodox electron spectroscopies, to circumvent the problems caused by the absence of large single crystals of Pu with well-defined surfaces. Our approach includes the techniques of resonant photoelectron spectroscopy, x-ray absorption spectroscopy, electron energy loss spectroscopy, Fano Effect measurements, and Bremstrahlung Isochromat Spectroscopy, including the utilization of micro-focused beams to probe single-crystallite regions of polycrystalline Pu samples.

  5. Recycling U and Pu in LWR

    International Nuclear Information System (INIS)

    Zheng Hualing.

    1986-01-01

    This article, from viewpoints of technical feasibility, safety evaluation and socioeconomic benefit-risk analysis, introduces and comments on history and status of recycling U and Pu in LWR, dealing with reactor, reprocessing, conversion and fuel element fabrication et al. Author has analysed LWR fuel cycle strategies in China and made a proposal

  6. Review of 241 Pu resonance parameters

    International Nuclear Information System (INIS)

    Derrien, H.

    1981-10-01

    The status of 241 Pu resonance parameters is reviewed. The most important recent results are compared in some energy ranges, both from single level and multilevel point of view. It appears that an accurate set of resonance parameters is not still obtained for a general description of the cross-sections in the resonance region. Some recommendations are given for further experiments or evaluations

  7. Structures and potential energy functions of Pu3 molecule

    International Nuclear Information System (INIS)

    Meng Daqiao; Jiang Gang; Liu Xiaoya; Luo Deli; Zhu Zhenghe

    2001-01-01

    Density functional (B3LYP) method with relativistic effective core potential (RECP) has been used to optimize the structures of Pu 2 and Pu 3 molecules. The results show that the ground states of Pu 2 and Pu 3 molecules are of D ∞h and D 3h symmetry, and of 13 and 19 fold, respectively. The spectral constants of Pu 2 , ω e = 52.3845 cm -1 and ω e x e = 0.0201 cm -1 , and the harmonic frequencies of Pu 3 , ν 1 = 56.9007 cm -1 , ν 2 = 57.1816 cm - '1 and ν 3 = 64.0785 cm -1 , have also been obtained on the B3LYP/RECP level. The potential energy functions of Pu 2 and Pu 3 have been derived, for the first time so far as known, from normal equation fitting and the many-body expansion theory

  8. Experimental validation of Pu-Sm evolution model for CANDU-6 power transients

    International Nuclear Information System (INIS)

    Coutsiers, Eduardo E.; Pomerantz, Marcelo E.; Moreno, Carlos A.

    2000-01-01

    Development of a methodology to evaluate the reactivity produced by Pu-Sm transient, effect displayed after power transients. This methodology allows to predict the behavior of liquid zones with which the fine control of CANDU reactor power is made. With this information, it is easier to foresee the refueling demand after power movements. The comparison with experimental results showed good agreement. (author)

  9. Genetic mapping, marker assisted selection and allelic relationships for the Pu 6 gene conferring rust resistance in sunflower.

    Science.gov (United States)

    Bulos, Mariano; Vergani, Pablo Nicolas; Altieri, Emiliano

    2014-09-01

    Rust resistance in the sunflower line P386 is controlled by Pu 6 , a gene which was reported to segregate independently from other rust resistant genes, such as R 4 . The objectives of this work were to map Pu 6 , to provide and validate molecular tools for its identification, and to determine the linkage relationship of Pu 6 and R 4 . Genetic mapping of Pu 6 with six markers covered 24.8 cM of genetic distance on the lower end of linkage Group 13 of the sunflower consensus map. The marker most closely linked to Pu 6 was ORS316 at 2.5 cM in the distal position. ORS316 presented five alleles when was assayed with a representative set of resistant and susceptible lines. Allelism test between Pu 6 and R 4 indicated that both genes are linked at a genetic distance of 6.25 cM. This is the first confirmation based on an allelism test that at least two members of the R adv /R 4 /R 11 / R 13a /R 13b /Pu 6 cluster of genes are at different loci. A fine elucidation of the architecture of this complex locus will allow designing and constructing completely new genomic regions combining genes from different resistant sources and the elimination of the linkage drag around each resistant gene.

  10. Radiation protection problems with sealed Pu radiation sources

    International Nuclear Information System (INIS)

    Naumann, M.; Wels, C.

    1982-01-01

    A brief outline of the production methods and most important properties of Pu-238 and Pu-239 is given, followed by an overview of possibilities for utilizing the different types of radiation emitted, a description of problems involved in the safe handling of Pu radiation sources, and an assessment of the design principles for Pu-containing alpha, photon, neutron and energy sources from the radiation protection point of view. (author)

  11. Transplacental absorption of 238Pu in rats and guinea pigs

    International Nuclear Information System (INIS)

    Sullivan, M.F.

    1980-01-01

    Pregnant rats and guinea pigs were injected intravenously with 238 Pu citrate to determine if the potential for in utero accumulation of 238 Pu by these two species is related to the stage of development at which immunity is gained. Although guinea pigs retained more 238 Pu after birth than rats, the difference was not significant

  12. Autoradiographic measurement of Pu distribution in mixed-oxide nuclear fuel

    International Nuclear Information System (INIS)

    Green, D.R.; Rasmussen, D.E.; Gray, W.H.

    1976-09-01

    The autoradiographic method described was developed for rapid, economical determination of the Pu distribution and microhomogeneity in mixed oxide fuel. High Pu concentration regions of any size down to 13 microns in diameter can be reproducibly resolved using this method. The new method uses computerized scanning and analysis, and includes automatic self-calibration to virtually elimate variations resulting from photographic film and processing. The speed of this new method allows analysis of enough data to ensure statistical reliability of occurrence frequencies, even for sparse populations of Pu-rich regions with diameters greater than 60 microns. Determination of these occurrence frequencies is an important factor in controlling fuel quality to ensure safe, efficient operation in a Liquid Metal Fast Breeder Reactor

  13. Determination of Pu in soil samples; Determinacion de Pu en muestras de suelo

    Energy Technology Data Exchange (ETDEWEB)

    Torres C, C. O.; Hernandez M, H.; Romero G, E. T. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Vega C, H. R., E-mail: carioli_32907@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    The irreversible consequences of accidents occurring in nuclear plants and in nuclear fuel reprocessing sites are mainly the distribution of different radionuclides in different matrices such as the soil. The distribution in the superficial soil is related to the internal and external exposure to the radiation of the affected population. The internal contamination with radionuclides such as Pu is of great relevance to the nuclear forensic science, where is important to know the chemical and isotopic compositions of nuclear materials. The objective of this work is to optimize the radiochemical separation of plutonium (Pu) from soil samples and to determine their concentration. The soil samples were prepared using acid digestion assisted by microwave; purification of Pu was carried out with AG1X8 resin using ion exchange chromatography. Pu isotopes were measured using ICP-SFMS. In order to reduce the interference due to the presence of {sup 238}UH {sup +} in the samples, a solvent removal system (Apex) was used. In addition, the limit of detection and quantification of Pu was determined. It was found that the recovery efficiency of Pu in soil samples ranges from 70 to 93%. (Author)

  14. Neutron inelastic-scattering cross sections of 232Th, 233U, 235U, 238U, 239Pu and 240Pu

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-01-01

    Differential-neutron-emission cross sections of 232 Th, 233 U, 235 U, 238 U, 239 Pu and 240 Pu are measured between approx. = 1.0 and 3.5 MeV with the angle and magnitude detail needed to provide angle-integrated emission cross sections to approx. 232 Th, 233 U, 235 U and 238 U inelastic-scattering values, poor agreement is observed for 240 Pu, and a serious discrepancy exists in the case of 239 Pu

  15. Pu speciation in actual and simulated aged wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lezama-pacheco, Juan S [Los Alamos National Laboratory; Conradson, Steven D [Los Alamos National Laboratory

    2008-01-01

    X-ray Absorption Fine Structure Spectroscopy (XAFS) at the Pu L{sub II/III} edge was used to determine the speciation of this element in (1) Hanford Z-9 Pu crib samples, (2) deteriorated waste resins from a chloride process ion-exchange purification line, and (3) the sediments from two Waste Isolation Pilot Plant Liter Scale simulant brine systems. The Pu speciation in all of these samples except one is within the range previously displayed by PuO{sub 2+x-2y}(OH){sub y}{center_dot}zH{sub 2}O compounds, which is expected based on the putative thermodynamic stability of this system for Pu equilibrated with excess H{sub 2}O and O{sub 2} under environmental conditions. The primary exception was a near neutral brine experiment that displayed evidence for partial substitution of the normal O-based ligands with Cl{sup -} and a concomitant expansion of the Pu-Pu distance relative to the much more highly ordered Pu near neighbor shell in PuO{sub 2}. However, although the Pu speciation was not necessarily unusual, the Pu chemistry identified via the history of these samples did exhibit unexpected patterns, the most significant of which may be that the presence of the Pu(V)-oxo species may decrease rather than increase the overall solubility of these compounds. Several additional aspects of the Pu speciation have also not been previously observed in laboratory-based samples. The molecular environmental chemistry of Pu is therefore likely to be more complicated than would be predicted based solely on the behavior of PuO{sub 2} under laboratory conditions.

  16. Determination of 240Pu/239Pu isotope ratios in Kara Sea and Novaya Zemlya sediments using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Oughton, D.H.; Skipperud, L.; Salbu, B.; Fifield, L.K.; Cresswell, R.C.; Day, J.P.

    1999-01-01

    Accelerator mass spectrometry (AMS) has been used to determine Pu activity concentrations and 240 Pu/ 239 Pu isotope ratios in sediments from the Kara Sea and radioactive waste dumping sites at Novaya Zemlya. Measured 239,240 Pu activities ranged from 0.06 - 9.8 Bq/kg dry weight, 240 Pu/ 239 Pu atom ratios ranged from 0.13 to 0.28, and 238 Pu/ 239,240 Pu activity ratios from 0.02 to 0.6. Perturbations from global fallout isotope ratios were evident at three sites: the Yenisey Estuary and Abrosimov Fjords where 240 Pu/ 239 Pu ratios were lower (0.13-0.14); and Stepovogo Fjord sediments where ratios were higher (up to 0.28) than fallout ratios. Based on procedural blanks, detection limits for AMS were below 1 fg Pu and the method showed good precision for isotope ratio measurements, minimal matrix, interference and memory effects. For high level samples, comparison between alpha spectrometry and AMS gave good agreement for measurement of 239,240 Pu activity concentrations. (author)

  17. Dose-response study in F344 rats exposed to (U,Pu)O2 or PuO2

    International Nuclear Information System (INIS)

    Mewhinney, J.A.; Eidson, A.F.; Hahn, F.F.; Scott, B.R.; Seiler, F.A.; Boecker, B.B.

    1987-01-01

    The relationship of radiation dose to lung and the biological effect observed was investigated following inhalation of two types of plutonium-containing particulate materials in rats. Bulk powder samples of the two materials were obtained from within gloveboxes used in the routine manufacture of mixed plutonium and uranium oxide nuclear fuel. The materials were a solid solution of uranium and plutonium treated at 1750 0 C and a PuO 2 feedstock. Groups of rats received a single inhalation exposure to a material to achieve one of three levels of initial pulmonary burden. Rats were maintained for their lifespan to observe the biological effects produced. These effects were observed in the lungs of rats exposed to either type of particle. The same types of lung cancer were produced by both particulate materials. The incidences of cancers were also similar at comparable levels of initial pulmonary burden for the two materials. The crude incidence of lung cancers for rats exposed to these materials was not different than those reported for similar studies that used laboratory-produced aerosols of PuO 2 . Using a linear dose-effect model, the relative risk of lung cancer for rats exposed to these industrial materials was 2.3 +- 1.0 (SE) at a lung dose of 100 rad. The doubling dose for lung cancers was 78 +- 63 rad to lung to median life span. 21 refs., 9 figs., 10 tabs

  18. Electrodeposition of uranium and transuranic metals (Pu) on solid cathode

    International Nuclear Information System (INIS)

    Laplace, A. F.; Lacquement, J.; Willitt, J. L.; Finch, R. A.; Fletcher, G. A.; Williamson, M. A.

    2008-01-01

    The results from a study of U and Pu metal electrodeposition from molten eutectic LiCl-KCl on a solid inert cathode are presented. This study has been conducted using ∼ to 50 g of U-Pu together with rare earths (mostly Nd) and 1.5 kg of salt. The introduction of a three-electrode probe with an Ag/AgCl reference electrode has allowed voltammetric measurement during electrolysis and control of the cathode potential versus the reference. Cyclic and square-wave voltammetric measurements proved to be very useful tools for monitoring the electrolysis as well as selecting the cathode versus reference potential to maximize the separation between actinides and rare earths. The voltammetric data also highlighted the occurrence of back reactions between the cathode deposit and oxidizing equivalents formed at the anode that remained in the molten salt electrolyte. Any further electrolysis test needs to be conducted continuously and followed by immediate removal of the cathode to minimize those back reactions. (authors)

  19. Characterization of a neutron source of 239PuBe

    International Nuclear Information System (INIS)

    Hernandez V, R.; Chacon R, A.; Hernandez D, V. M.; Mercado, G. A.; Vega C, H. R.; Ramirez G, J.

    2009-10-01

    The spectrum equivalent dose and environmental equivalent dose f a 239 PuBe source have been determined. The appropriate handling of a neutron source depends on the knowledge of its characteristics, such as its energy distribution, total rate of flowing and dosimetric magnitudes. In many facilities have not spectrometer that allows to determine the spectrum and then area monitors are used that give a dosimetric magnitude starting from measuring the flowing rate and the use of conversion factors, however this procedure has many limitations and it is preferable to measure the spectra and starting from this information the interest dosimetric magnitudes are calculated. In this work a Bonner sphere spectrometer has been used with a 6 LiI(Eu) scintillator obtaining the count rates that produce, to a distance of 100 cm, a 239 PuBe source of 1.85E(11) Bq. The spectrum was reconstructed starting from the count rates using BUNKIUT code and response matrix UTA4. With the spectrum information was calculated the source intensity, total flow, energy average, equivalent dose rate, environmental equivalent dose rate, equivalent dose coefficient and environmental equivalent dose coefficient. By means of two area monitors for neutrons, Eberline ASP-1 and LB 6411 of Berthold the equivalent dose and environmental equivalent dose were measured. The determinate values were compared with those reported in literature and it found that are coincident inside 17%. (Author)

  20. 238Pu fuel form activities, March 1-September 30, 1985

    International Nuclear Information System (INIS)

    1986-01-01

    The SRP portion of this report summarizes production 238 PuO 2 fuel forms for use in radioisotopic thermoelectric generators (RTG's) in the Plutonium Fuel Form (PuFF) Facility at the Savannah River Plant. The PuFF Facility began producing iridium-encapsulated, 62.5-watt 238 PuO 2 right circular cylinders for GPHS (General Purpose Heat Source) RTG's in June 1980; this program was completed in December 1983. The PuFF Facility has been placed in a production readiness mode of operation pending funding of additional heat source programs

  1. Comparison of the ENDF/B-V and SOKRATOR evaluations of 235U, 239Pu, 240Pu and 241Pu at low neutron energies

    International Nuclear Information System (INIS)

    de Saussure, G.; Wright, R.Q.

    1981-01-01

    The US and USSR's most recent evaluationsof 235 U, 239 Pu, 240 Pu and 241 Pu are compared over the thermal region and over the first few resonances. The two evaluations rest on essentially the same experimental data base and the differences reflect different approaches to the representation of the cross sections or different weightings of the experimental results. It is found that over the thermal and resolved ranges the two evaluations are very similar. Some differences in approaches are briefly discussed

  2. Thermodynamic evaluation of liquid Cd cathode containing U and Pu

    International Nuclear Information System (INIS)

    Kurata, Masaki; Uozumi, Koichi; Kato, Tetsuya; Iizuka, Masatoshi

    2009-01-01

    In our previous study, a mixture of U and Pu was recovered in liquid Cd cathode from molten salt under various conditions of the U:Pu ratio. Two important things were observed. The first was that three kinds of precipitated phase had been detected in the saturated liquid Cd cathode, such as a U metal and two kinds of U-Pu-Cd compound. The compositions of the compounds were roughly (U+Pu):Cd=1:11 and (U+Pu):Cd=1:6. The second was that the U metal had selectively precipitated in the saturated liquid Cd cathode under the condition that the U:Pu ratio is higher than about 0.8 in the liquid Cd phase. In the present study, phase diagrams were evaluated by the CALPHAD method on the liquid Cd cathode containing U and Pu. The U-Pu-Cd compounds were modeled as MCd 11 -type and MCd 6 -type, respectively, based on the reported binary phase diagrams of U-Cd and Pu-Cd. The calculated result reasonably agreed with the experimental observations. The variations in the U and Pu activities were estimated along with the U:Pu ratio, which is related to the precipitation of various phases in the liquid Cd cathode. (author)

  3. Low level scintillation counting of 239Pu

    International Nuclear Information System (INIS)

    Fueloep, M.; Minarik, F.; Cierna, V.

    1984-01-01

    For measuring the content of 239 Pu in samples taken from the working or living environment, methods should be used which are sufficiently sensitive for determining activities of the order of 10 -3 Bq. It is useful to use liquid scintillators for reasons of their 4π geometry and the exclusion of kinetic energy losses of particles detected in the sample and on the path between the sample and the detector. The method of background discrimination according to pulse shape may be used to suppress gamma background in the area of alpha particle peaks to the level 2.5x10 -4 s -1 . The diagram is given of electronic circuits for shape discrimination. The scintillator used was a SLS-31 with a PBD activator, a POPOP spectrum shifter and a mixture of solvents: toluene, dioxane and methanol. The efficiency of 239 Pu alpha particle detection is estimated at 78% and may further be improved by improving shape discrimination. (M.D.)

  4. Carbothermic synthesis of (Cm,Pu)N

    International Nuclear Information System (INIS)

    Takano, Masahide; Itoh, Akinori; Akabori, Mitsuo; Ogawa, Toru; Numata, Masami; Okamoto, Hisato

    2001-01-01

    Nitrides are being considered as fuel candidates for the transmutation of minor actinides. Carbothermic reduction of oxides is an effective method to fabricate nitride fuels. In this study, (Cm 0.40 ,Pu 0.60 )N was synthesized by the carbothermic reduction of the mixed oxide in N 2 . By applying excess carbon, an oxide-free nitride was obtained at 1773 K. The lattice parameter of the oxide-free sample was 0.4948 nm, and that of the nitride with oxides was 0.4974 nm. The former value agreed well with that estimated from the literature values for CmN and PuN. The larger lattice parameter of the latter sample is considered to be due to the oxygen dissolved in the nitride. (authors)

  5. Artificial radioactivity and marine environment. Study of 238Pu, 239Pu+240Pu, 241Pu and 241Am in the Mediterranean sea

    International Nuclear Information System (INIS)

    Ballestra, Serge.

    1980-10-01

    This paper is in two parts. Part one is about the methods for analyzing transuranium elements particularly the development of an analytical process for plutonium and for perfecting an Americium analyzing method, capable of treating samples of 200 litres of sea water, 100 grams of sediment and 100 grams of biological matter. Part two concerns the in situ determinations carried out within the scope of the study on the distribution and behaviour of transuranium elements in the Mediterranean sea. The high sea studies concerned the effects of atmospheric fall out and the vertical distribution of Pu and Am. Studies along the coasts enabled a quantitative study to be made of the contribution of rivers to the Mediterranean and to study the distribution of Pu along the French Mediterranean coast line [fr

  6. Acetaldoxime - a promising reducing agent for Pu and Np ions in the Purex process

    International Nuclear Information System (INIS)

    Koltunov, V.S.; Baranov, S.M.; Mezhov, E.A.; Pastuschak, V.G.; Koltunov, G.V.; Taylor, R.J.

    2000-01-01

    This paper discusses the properties of acetaldoxime as an example of a novel class of salt-free organic reductants for Np and Pu ions, the monoximes. The products of its reactions with Np(VI) and Pu(IV) are Np(V), Pu(III), N 2 O, CH 3 CHO and CH 3 COOH. The rate of the Np(VI) - CH 3 CHNOH reaction is first order relative to both reagents and negative first order relative to HNO 3 . The rate constant is k 1 = 254 ± 10 min -1 at 26 deg. C and the activation energy is E = 62.6 ± 2.6 kJ/mol. The orders of the Pu(IV) - CH 3 CHNOH reaction for Pu(IV), Pu(III), CH 3 CHNOH and HNO 3 are equal to 2, -1, 1.1 and -2.2, respectively, and the rate constant is k 2 25.3 ± 1.9 M 1.1 min -1 at 19.5 deg. C. The activation energy is 87.7 ± 2.8 kJ/mol. The likely mechanisms of these reactions are reviewed. Acetaldoxime is stable in HNO 3 solutions when [HNO 3 ] 3 ] = 3.8 - 3.9 M at 35.5 deg. C) a rapid process of HNO 2 formation and acetaldoxime oxidation occurs. Investigations were implemented to study the kinetics of the acetaldoxime oxidation with HNO 2 when [HNO 3 ] 3 under 'critical' conditions. (authors)

  7. Age and carcinogenesis of 239Pu

    International Nuclear Information System (INIS)

    Mahlum, D.D.; Sikov, M.R.; Hess, J.O.; Zwicker, G.M.; Carr, D.B.

    1979-01-01

    The late effects of 239 Pu have been studied after its administration to perinatal, juvenile and adult rats. Adults and weanlings were injected intravenously, newborns intracardially and 19-day foetuses by intravenous injection of the dam. Dose levels were selected to deliver radiation doses of approximately 7, 23, or 70 rads to the femur of all ages during the first 10 days post injection; in general these values were achieved as shown by tissue analysis. Dose rates subsequently diverged, resulting in widely varying cumulative radiation doses for the four age groups. Survival times of rats exposed post-natally were progressively decreased by increasing dose. No decrement in survival was found for those exposed prenatally. Bone tumour incidence was increased by exposure to Pu in all age groups. The younger rats were less sensitive on an administered dose basis, but perhaps more sensitive on the basis of cumulative radiation dose. Prenatally exposed animals, which were cross-fostered to control females, showed a higher incidence of bone tumours than did those that remained with their mother. In the adult the predominant fraction of the bone tumours was found in the extremities with a lesser fraction in the vertebrae, pelvis and other sites. In the two younger age groups the majority of the tumours were in the head with few in the extremities or vertebrae. The incidence of mammary tumours was also elevated in the adult, weanling and prenatal groups by the administration of 239 Pu. (author)

  8. Preparation of additional supplies of 244Pu

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Newman, E.; Alexander, C.W.

    1985-01-01

    In the mid-1970s, gram quantities of the man-made isotope 244 Pu were produced in high purity for basic research as a by-product of a program to prepare gram quantities of 252 Cf. Because 244 Pu is not produced in appreciable quantities in standard power reactor fuel, this nuclide has become extremely useful in the application of isotope dilution mass spectrometry (IDMS), a high-precision analytical technique, to problems of plutonium accountability in support of international safeguards agreements. Although only a small amount (a fraction of a microgram) is needed for each analysis, the present supply of certified nuclear reference standard SRM-996 is expected to last only an additional 3 to 5 years. Three options for producing additional supplies of this rare and valuable material were examined. The options encompassed the production of from 1 to 8.5 g during time spans of from 3 to 10 years. Unit costs ranged from $2300 to $7200 per mg of plutonium of >97% 244 Pu. While the paper concludes that the short-term option can be pursued along with further study of the longer-term options, this should not be regarded as an offer or a commitment on the part of the US Department of Energy (USDOE) to furnish the described material

  9. Preparation of additional supplies of 244Pu

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Newman, E.; Alexander, C.W.

    1985-01-01

    In the mid-1970s, gram quantities of the man-made isotope 244 Pu were produced in high purity for basic research as a by-product of a program to prepare gram quantities of 252 Cf. Because 244 Pu is not produced in appreciable quantities in standard power reactor fuel, this nuclide has become extremely useful in the application of isotope dilution mass spectrometry (IDMS), a high-precision analytical technique, to problems of plutonium accountability in support of international safeguards agreements. Although only a small amount (a fraction of a microgram) is needed for each analysis, the present supply of certified nuclear reference standard SRM-996 is expected to last only an additional 3 to 5 years. Three options for producing additional supplies of this rare and valuable material were examined. The options encompassed the production of from 1 to 8.5 g during time spans of from 3 to 10 years. Unit costs ranged from $2300 to $7200 per mg of plutonium of >97% 244 Pu. While the paper concludes that the short-term option can be pursued along with further study of the longer-term options, this should not be regarded as an offer or a commitment on the part of the U.S. Department of Energy (USDOE) to furnish the described material. (author)

  10. ²³⁹Pu and ²⁴⁰Pu inventories and ²⁴⁰Pu/²³⁹Pu atom ratios in the equatorial Pacific Ocean water column.

    Science.gov (United States)

    Yamada, Masatoshi; Zheng, Jian

    2012-07-15

    The (239+240)Pu concentrations and (240)Pu/(239)Pu atom ratios were determined by alpha spectrometry and inductively coupled plasma mass spectrometry for seawater samples from two stations, one at the equator and the other in the equatorial South Pacific. To better understand the fate of Pu isotopes, this study dealt with the contribution of the close-in fallout Pu from the Pacific Proving Grounds (PPG) in water columns of the Pacific Ocean. The (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m at the equator station were 10.4, 8.9 and 19.3 Bq m(-2), respectively. Further, no noticeable difference was observed in (239)Pu, (240)Pu and (239+240)Pu inventories over the depth interval 0-3000 m between the two stations. The total (239+240)Pu inventories were significantly higher than the expected cumulative deposition density of global fallout. Water column (239+240)Pu inventories measured in this study were lower than those reported for comparable stations in the Geochemical Ocean Sections Study, indicating that these inventories have been decreasing at average rates of 0.89 ± 0.07 and 0.16 ± 0.07 Bq m(-2)yr(-1) at the equator and equatorial South Pacific stations, respectively, from 1973 to 1990. The obtained (240)Pu/(239)Pu atom ratios were higher than the mean global fallout ratio of 0.18. These high atom ratios proved the existence of close-in tropospheric fallout Pu from the PPG in the Marshall Islands. The (239+240)Pu inventories originating from the close-in fallout in the entire water column were estimated to be 11.1 Bq m(-2) at the equator station and 7.1 Bq m(-2) at the equatorial South Pacific Ocean station, and the relative percentages of close-in fallout Pu were 40% at the former and 34% at the latter. A significant amount of close-in fallout Pu originating from the PPG has been transported to deep layers below the 1000 m depth in the equatorial Pacific Ocean. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Soil-plant transfer factors for Pu in the field and laboratory in relation to desorption from the solid phase

    International Nuclear Information System (INIS)

    Mudge, S.; Kelly, M.; Hamilton-Taylor, J.; Horrill, A.D.

    1990-01-01

    Laboratory hydroponics experiments using an environmentally contaminated sediment as source of Pu, were carried out to determine the soil-plant, soil solution-plant and root-plant transfer factors. Soil-plant transfer factors, calculated from field observations, varied according to the degree of animal usage and were more than two orders of magnitude larger than those from the laboratory experiments. The discrepancies between field and laboratory measurements are probably due to the complex sediment speciation and desorption chemistry of Pu. The transfer factors based on the solution or root activities are likely to provided a better estimate of the vegetation activity than those based on the solid phase activity. (author)

  12. Containment of Nitric Acid Solutions of Plutonium-238

    International Nuclear Information System (INIS)

    Reimus, M.A.H.; Silver, G.L.; Pansoy-Hjelvik, L.; Ramsey, K.

    1999-01-01

    The corrosion of various metals that could be used to contain nitric acid solutions of Pu-238 has been studied. Tantalum and tantalum/2.5% tungsten resisted the test solvent better than 304L stainless steel and several INCONEL alloys. The solvent used to imitate nitric acid solutions of Pu-238 contained 70% nitric acid, hydrofluoric acid, and ammonium hexanitratocerate

  13. Dosimetry of 239Pu in dogs that inhaled monodisperse aerosols of 239PuO2

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Muggenburg, B.A.; Hahn, F.F.; Mewhinney, J.A.; Seiler, F.A.; Boecker, B.B.; McClellan, R.O.

    1987-01-01

    Existing data from human exposure cases and experimental animal studies on the fate and dosimetry of inhaled insoluble Pu particles are inadequate to provide a comprehensive description and evaluation of the tissues at risk from the alpha radiations of Pu. To improve our knowledge of the dosimetry of inhaled insoluble 239 PuO 2 , this paper describes the uptake and retention of 239 Pu in the tissues of dogs that received single inhalation exposures to monodisperse aerosols of 239 PuO 2 . These data include times through 3 years after exposure. Using analytical functions fitted to each tissue data set, 1100-day radiation doses were calculated for lung, liver, skeleton, kidney, spleen, and tracheobronchial, mediastinal, sternal, hepatic, mandibular, and retropharyngeal lymph nodes. The dosimetry results suggest that the lung and lymph nodes associated with lymphatic drainage of the respiratory tract are the principal sites of alpha irradiation. However, the doses for the different respiratory tract lymph nodes vary by a factor of 2000, suggesting that assuming equivalent doses to respiratory tract lymph nodes is not appropriate. Other tissues receive radiation doses also but at levels one to three orders of magnitude less than the lung. Particle size dependence on uptake and retention was noted for the skeleton, mediastinal lymph nodes, hepatic lymph nodes, retropharyngeal lymph nodes, and mandibular lymph nodes

  14. Post-irradiation examination of CANDU fuel bundles fuelled with (Th, Pu)O2

    International Nuclear Information System (INIS)

    Karam, M.; Dimayuga, F.C.; Montin, J.

    2010-01-01

    AECL has extensive experience with thoria-based fuel irradiations as part of an ongoing R&D program on thorium within the Advanced Fuel Cycles Program. The BDL-422 experiment was one component of the thorium program that involved the fabrication and irradiation testing of six Bruce-type bundles fuelled with (Th, Pu)O 2 pellets. The fuel was manufactured in the Recycle Fuel Fabrication Laboratories (RFFL) at Chalk River allowing AECL to gain valuable experience in fabrication and handling of thoria fuel. The fuel pellets contained 86.05 wt.% Th and 1.53 wt.% Pu in (Th, Pu)O 2 . The objectives of the BDL-422 experiment were to demonstrate the ability of 37-element geometry (Th, Pu)O 2 fuel bundles to operate to high burnups up to 1000 MWh/kgHE (42 MWd/kgHE), and to examine the (Th, Pu)O 2 fuel performance. This paper describes the post-irradiation examination (PIE) results of BDL-422 fuel bundles irradiated to burnups up to 856 MWh/kgHE (36 MWd/kgHE), with power ratings ranging from 52 to 67 kW/m. PIE results for the high burnup bundles (>1000 MWh/kgHE) are being analyzed and will be reported at a later date. The (Th, Pu)O 2 fuel performance characteristics were superior to UO 2 fuel irradiated under similar conditions. Minimal grain growth was observed and was accompanied by benign fission gas release and sheath strain. Other fuel performance parameters, such as sheath oxidation and hydrogen distribution, are also discussed. (author)

  15. {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am levels in the terrestrial and aquatic environment of the Loire and Garonne rivers basins (France)

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, G.; Mokili, M.B.; Le Roy, C.; Pagano, V. [SUBATECH/IN2P3 (France); Gontier, G.; Boyer, C. [EDF-DPI-DIN-CIDEN (France); Chardon, P. [CNRS/IN2P3 (France); Hemidy, P.Y. [EDF-DPN-UNIE-GPRE-IEV (France)

    2014-07-01

    Plutonium and americium long-lived alpha emitter isotopes can be found in the environment because of atmospheric global fallout due to thermonuclear tests performed between 1945 and 1980, to the American SNAP 9A satellite explosion in 1964, to the Chernobyl nuclear power plant accident,... In France, the nuclear safety authority does not allow the release of artificial alpha emitters from nuclear power plants. Thus, monitoring is performed to verify the absence of these alpha emitters in liquid discharges to respect the limits set by the regulations. These thresholds ensure a very low dosimetric impact to the population compared to other radionuclides. With the objective of environmental monitoring around nuclear facilities, activity measurements of long-lived alpha emitters are carried out to detect the traces of these radionuclides. Analysis of low activity by alpha spectrometry after chemical steps were performed and used to determine the {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am activities on a large set of environmental solid samples likely to be encountered in environmental monitoring as soils, sediments, terrestrial and aquatic bio-indicators. The samples collected in the terrestrial and aquatic environment of the Loire and Garonne rivers basins (France) was investigated for the 2009-2014 period. It was found that the mean activity concentration of the most frequently detected was for the radionuclide {sup 238}Pu: from <0.00031 to 0.0061 Bq/kg dry in terrestrial samples and from <0.00086 to 0.011 Bq/kg dry in aquatic samples; for the radionuclide {sup 239+240}Pu: from 0.00041 to 0.150 Bq/kg dry in terrestrial samples and from 0.0023 to 0.240 Bq/kg dry in aquatic samples and for the radionuclide {sup 241}Am: from <0.00086 to 0.087 Bq/kg dry in terrestrial samples and from 0.0022 to 0.120 Bq/kg dry in aquatic samples. {sup 238}Pu/{sup 239+240}Pu and {sup 241}Am/{sup 239+240}Pu ratios determined are in accordance with an environmental contamination due to

  16. A multi-radionuclide approach to evaluate the suitability of {sup 239+240}Pu as soil erosion tracer

    Energy Technology Data Exchange (ETDEWEB)

    Meusburger, Katrin, E-mail: Katrin.Meusburger@unibas.ch [Environmental Geosciences, University of Basel, Bernoullistrasse 30, CH-4056 Basel (Switzerland); Mabit, Lionel, E-mail: L.Mabit@iaea.org [Soil and Water Management and Crop Nutrition Laboratory, FAO/IAEA Agriculture & Biotechnology Laboratory, IAEA Laboratories, Seibersdorf (Austria); Ketterer, Michael, E-mail: mkettere@msudenver.edu [Chemistry Department, Metropolitan State University of Denver, CO (United States); Park, Ji-Hyung, E-mail: jhp@ewha.ac.kr [Department of Environmental Science & Engineering, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Sandor, Tarjan [Radioanalytical Reference Laboratory, Central Agricultural Office Food and Feed Safety Directorate (Hungary); Porto, Paolo, E-mail: paolo.porto@unirc.it [Dipartimento di AGRARIA, Università degli Studi “Mediterranea” di Reggio Calabria (Italy); Alewell, Christine, E-mail: Christine.Alewell@unibas.ch [Environmental Geosciences, University of Basel, Bernoullistrasse 30, CH-4056 Basel (Switzerland)

    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 {sup 239}Pu and {sup 240}Pu as a method to assess soil erosion magnitude by comparison to more established fallout radionuclides such as {sup 137}Cs and {sup 210}Pb{sub ex}. 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 (> 25 t ha{sup −1} yr{sup −1}). Pu isotopes further allowed determining the origin of the fallout. Both {sup 240}Pu/{sup 239}Pu atomic ratios and {sup 239+240}Pu/{sup 137}Cs activity ratios were close to the global fallout ratio. However, the depth profile of the {sup 239+240}Pu/{sup 137}Cs activity ratios in undisturbed sites showed lower ratios in the top soil increments, which might be due to higher migration rates of {sup 239+240}Pu. The activity ratios further indicated preferential transport of {sup 137}Cs from eroded sites (higher ratio compared to the global fallout) to the depositional sites (smaller ratio). As such the {sup 239+240}Pu/{sup 137}Cs activity ratio offered a new approach to parameterize a particle size correction factor that can be applied when both {sup 137}Cs and {sup 239+240}Pu have the same fallout source. Implementing this particle size correction factor in the conversion of {sup 137}Cs inventories resulted in comparable estimates of soil loss for {sup 137}Cs and {sup 239+240}Pu. The comparison among the different fallout radionuclides highlights the suitability of {sup 239+240}Pu through less preferential transport compared to {sup 137}Cs and the possibility to gain information regarding the origin of the fallout. In conclusion, {sup 239+240}Pu is a promising soil erosion tracer, however, since the behaviour i.e. vertical migration in the

  17. 242Pu: Preliminary evaluation with consideration of 240Pu, and some sensitivity results

    International Nuclear Information System (INIS)

    Jary, J.; Lagrange, C.; Philis, C.

    1978-01-01

    A preliminary evaluation of 242 Pu nuclear data is presented for the neutron energy range from 10 keV to 20 MeV. The fission cross section is based upon recent experimental measurements on 242 Pu. The remaining cross sections have been calculated using various nuclear models with parameters obtained mainly by both fits on 240 Pu experimental data and general reflexions on the actinides. Particular care has been taken of the direct interactions. The laws of secondary neutron energy spectra and the average number of neutrons produced per fission have been evaluated. The results have been placed in ENDF/BIV format and combined with the low energy region of ENDF/BIV MAT = 1161 data to make complete the evaluation over the whole energy range 10 -5 eV - 20 MeV. Finally, the sensitivities of some of these nuclear data available for reactor calculations are given in terms of the variation of the calculated critical masses

  18. Natural Pu-traces within the continental crust

    International Nuclear Information System (INIS)

    Ganz, M.; Barth, H.; Fuest, M.; Molzahn, D.; Brandt, R.

    1991-01-01

    Pu-traces are observed in the environmental all over the world, 'man made'-Pu as well as 'natural' Pu ( 239 Pu). 239 Pu occurs within a range of about 10 -12 g Pu/g sample in pitchblende. In the FRG, the deep-drilling project 'KTB, Kontinentales Tiefbohrprogramm', was started with the aim to obtain a very deep hole (14 km). We wanted to establish upper concentration limits for plutonium in samples from KTB. For a first investigation, we obtained a 400 g sample of granite from a pre-drill of KTB. Its Pu-concentration was ≤ (4.5 ± 2.5)x10 -16 g 239 Pu/g sample. To compare this result to the Pu-content in geological brines, we obtained a sample from a borehole at the Salton Sea Geothermal field (Southeastern California). In this sample we found an upper concentration limit of (2.1 ± 1.0)x10 -16 g 239 Pu/g sample. (orig.)

  19. Studies of U-Pu-C-Ti compounds

    International Nuclear Information System (INIS)

    Milet, C.

    1967-01-01

    The U-Pu-C-Ti compounds (5 to 20 atoms per cent Ti) have been studied in order to improve some properties of U-Pu-C carbides and to extend the existence field of the (U, Pu) C phase. The Pu/(U+Pu) ratio has been fixed to 15 per cent. All the alloys were elaborated and cast in an arc furnace. A two-phases field (U, Pu) C + Ti C exists which permits to avoid di- and sesqui-carbides and the (U, Pu) phase. An eutectic between (U, Pu) C and Ti C was found around 15 atoms per cent Ti. Practically the whole of the titanium is in Ti C form, titanium solubility in (U, Pu) C being inferior to 1 atom per cent. The most promising alloy are those containing two phases: (U, Pu) C+ Ti C. In comparison with the (U, Pu) C phase, titanium addition does not change very much the thermal expansion coefficients nor the thermal cycling behaviour between 160 and 1000 Celsius degrees which is excellent. On the other hand atmospheric corrosion behaviour is improved; compatibility with stainless steel is better; thermal conductivity, calculated from electrical resistivity K is enhanced: for U(0.85)-Pu(0.15)-C alloy we have K 0.179 W/cm.C at 1000 C and K = 0.187 W/cm.C at 1500 C, for U-Pu-C-Ti (10 atoms % Ti) alloy we have K = 0.193 W/cm.C at 1000 C and K = 0.205 W/cm.C at 1500 C. (author) [fr

  20. Direct reduction of 238PuO2 and 239PuO2 to metal

    International Nuclear Information System (INIS)

    Mullins, L.J.; Foxx, C.L.

    1982-02-01

    The process for reducing 700 g 239 PuO 2 to metal is a standard procedure at Los Alamos National Laboratory. This process is based on research for reducing 200 g 238 PuO 2 to metal. This report describes in detail the experiments and development of the 200-g process. The procedure uses calcium metal as the reducing agent in a molten CaCl 2 solvent system. The process to convert impure plutonia to high-purity metal by oxide reduction followed by electrorefining is also described

  1. On the fission probability for 235U, 239Pu and 241Pu

    International Nuclear Information System (INIS)

    Benzi, V.; Maino, G.; Menapace, E.

    1978-01-01

    An evaluation of the GAMMAsub(n)/GAMMAsub(f) ratio for the 236 U, 240 Pu and 242 Pu compound nuclei is carried out. First chance and second chance fission cross sections are estimated from the ''evaporation'' model; particularly, a largely increasing trend was found for the first chance fission cross section above the (n,n'f) process threshold. The GAMMAsub(n)/GAMMAsub(f) ratios for the analyzed nuclei show a bump-like structure, that seems to be in agreement with the theoretical predictions reported in literature

  2. Electrocatalytic performance of Pu(IV)/Pu(III) redox reaction at graphene modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Gupta, Ruma; Gamare, J.S.; Kamat, J.V.; Aggarwal, S.K.

    2014-01-01

    In this paper we explore the analytical perspectives of graphene modified electrode utilising commercially available graphene, which is well characterised, completely free from surfactants and has not been purposely oxidised or treated. We compare and critically contrast the electro-analytical performance of graphene modified glassy carbon electrodes (Gr/GC) with that of unmodified GC electrode towards Pu(IV)/Pu(III) redox reaction, monitoring of which has considerable importance in a plethora of areas where electrochemistry is conveniently and beneficially utilised for determination of nuclear fuels

  3. Acceptable knowledge summary report for combustible/noncombustible, metallic, and HEPA filter waste resulting from 238Pu fabrication activities

    International Nuclear Information System (INIS)

    Rogers, P.S.Z.; Foxx, C.L.

    1998-01-01

    All transuranic (TRU) waste must be sufficiently characterized and certified before it is shipped to the Waste Isolation Pilot Plant (WIPP). The US Environmental Protection Agency (EPA) allows use of acceptable knowledge (AK) for waste characterization. EPA uses the term AK in its guidance document and defines AK and provides guidelines on how acceptable knowledge should be obtained and documented. This AK package has been prepared in accordance with Acceptable Knowledge Documentation (TWCP-QP-1.1-021,R.2). This report covers acceptable knowledge information for five waste streams generated at TA-55 during operations to fabricate various heat sources using feedstock 238 Pu supplied by the Savannah River Site (SRS). The 238 Pu feedstock itself does not contain quantities of RCRA-regulated constituents above regulatory threshold limits, as known from process knowledge at SRS and as confirmed by chemical analysis. No RCRA-regulated chemicals were used during 238 Pu fabrication activities at TA-55, and all 238 Pu activities were physically separated from other plutonium processing activities. Most of the waste generated from the 238 Pu fabrication activities is thus nonmixed waste, including waste streams TA-55-43, 45, and 47. The exceptions are waste streams TA-55-44, which contains discarded lead-lined rubber gloves used in the gloveboxes that contained the 238 Pu material, and TA-55-46, which may contain pieces of discarded lead. These waste streams have been denoted as mixed because of the presence of the lead-containing material

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

    International Nuclear Information System (INIS)

    Hernandez-Mendoza, H.; Chamizo, E.; Yllera, A.; Garcia-Leon, M.; Delgado, A.

    2010-01-01

    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 239 Pu activity concentrations in urine of, at least, 30 μBq (13 fg 239 Pu). 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.

  5. Uncertainty propagation for the coulometric measurement of the plutonium concentration in MOX-PU4.

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2017-11-07

    This GUM WorkbenchTM propagation of uncertainty is for the coulometric measurement of the plutonium concentration in a Pu standard material (C126) supplied as individual aliquots that were prepared by mass. The C126 solution had been prepared and as aliquoted as standard material. Samples are aliquoted into glass vials and heated to dryness for distribution as dried nitrate. The individual plutonium aliquots were not separated chemically or otherwise purified prior to measurement by coulometry in the F/H Laboratory. Hydrogen peroxide was used for valence adjustment. The Pu assay measurement results were corrected for the interference from trace iron in the solution measured for assay. Aliquot mass measurements were corrected for air buoyancy. The relative atomic mass (atomic weight) of the plutonium from X126 certoficate was used. The isotopic composition was determined by thermal ionization mass spectrometry (TIMS) for comparison but not used in calculations.

  6. Efforts to save 244Pu in Mark 18A targets for use in international safeguards measurements

    International Nuclear Information System (INIS)

    Goldberg, Steven A.; Cappis, John; Clarke, Stephanie; Whitesel, Robert

    2001-01-01

    Full text: The Office of Arms Control and Nonproliferation and the Office of Security and Emergency Operations are working collaboratively to evaluate the disposition of a large quantity of the 244 Pu isotope contained in 65 Mark ISA targets at the Savannah River Site (SRS). 244 Pu is used as a standard reference material for plutonium analytical measurements required for both domestic and international safeguards. 244 Pu is particularly valuable for high accuracy measurements of plutonium in small samples containing trace quantities of plutonium (environmental analysis) and for measurements of material through-put in bulk processing facilities handling large volumes of plutonium and plutonium-bearing materials. In October 2000, an assessment team was tasked by the U.S. Department of Energy (DOE) Under Secretary to evaluate pathways and costs for the chemical separation and isotopic enrichment of the 244 Pu identified in the targets. Even though the target materials have recently been designated as a National Resource, they are scheduled for waste disposal unless funds can be identified and assigned to the project. Background information on the Mark ISA targets and a review of the assessment process are presented below to inform other organizations and governments of current efforts to examine potential disposition options and to solicit international cooperation for the extraction of the 244 Pu. Background - The United States possesses the bulk of the world's supply of the rare isotope 244 Pu. This isotope was produced by extremely long neutron irradiation of 242 Pu in a high-flux reactor during experiments used primarily to create isotopes of medical interest. In its separated enriched form, 244 Pu is regarded as the most accurate and desirable spike for safeguards, forensics, and environmental analysis of plutonium, allowing the simultaneous measurement of a sample for isotopic abundances and elemental concentration. Such measurements are a critical component of

  7. Electrochemical studies of plutonium(IV) complexes in aqueous nitrate solutions

    International Nuclear Information System (INIS)

    Kim, Seong-Yun; Asakura, Toshihide; Morita, Yasuji

    2005-01-01

    Electrochemistry has been used to investigate the behavior of plutonium (IV) in 1-7 M HNO 3 solutions. These Pu(IV) complexes were found to be reduced quasi-reversibly to Pu(III) species. The formal redox potentials (E 0 ) for Pu(IV)/Pu(III) couples were determined to be +0.721, +0.712, +0.706, +0.705, +0.704, 0.694, and +0.696 V (vs. Ag/AgCl(SSE)) for Pu(IV) complexes in 1, 2, 3, 4, 5, 6, 7 M HNO 3 solutions, respectively. These results indicate that the reduction product of Pu(IV) is Pu(III), which is considerably stable in HNO 3 solution. (author)

  8. Development of an U and Pu recovery process by molten salt electrorefining. Behavior of U and Pu at simultaneous recoveries into liquid cadmium cathodes

    International Nuclear Information System (INIS)

    Uozumi, Koichi; Kato, Tetsuya; Iizuka, Masatoshi; Inoue, Tadashi; Iwai, Takashi; Shirai, Osamu; Arai, Yasuo

    2003-01-01

    In order to study behaviors of U and Pu at simultaneous recoveries into liquid cadmium cathodes (LCCs) in the electrorefining of pyrometallurgical reprocessing, several experiments were conducted to recover U and Pu into LCCs at different U/Pu ratios in the salt phase. The major results were as follows: (1) The weight ratios of U and Pu in 120 g LCCs reached 10 wt.% (the tentative target), with current efficiencies higher than 80 %. (2) Under the conditions of U/Pu ratios in the initial salt phase less than 1/4.3, the amounts of recovered U and Pu were proportional to the passed electric charges, with the separation factors of U to Pu (= (U/Pu ration in the recovered product)/(U/Pu ratio in the salt)) between 1.2 and 2.0. (3) On the other hand, under the condition of U/Pu ratio in the initial salt phase at 1/1.73, only U was recovered into the LCC after the saturation of LCC with U and Pu. Accordingly, there will be a threshold in the U/Pu ratio of the salt phase for the simultaneous recovery of U and Pu. (4) Am showed a similar behavior to Pu. The separation factors of Am to Pu (=(AM/Pu ratio in the recovered product)/(Am/Pu ratio in the salt)) was 0.78, which means that Am is co-recovered with Pu into LCC. (author)

  9. Characterization of a Pu-bearing zirconolite-rich synroc

    International Nuclear Information System (INIS)

    Buck, E.C.; Ebbinghaus, B.; Bakel, A.J.; Bates, J.K.

    1996-01-01

    A titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi 2 O 7 ), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium- loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO 2- x . The Pu oxidation state in the zirconolite was determined to be mainly Pu 4+ , although some Pu 3+ was believed to be present

  10. Unsafe Coulomb excitation of $^{240-244}Pu$

    CERN Document Server

    Wiedenhöver, I; Hackman, L; Ahmad, I; Greene, J P; Amro, H; Carpenter, M P; Nisius, D T; Reiter, P; Lauritsen, T; Lister, C J; Khoo, T L; Siem, S; Cizewski, J A; Seweryniak, D; Uusitalo, J; Macchiavelli, A O; Chowdhury, P; Seabury, E H; Cline, D; Wu, C Y

    1999-01-01

    The high spin states of /sup 240/Pu and /sup 244/Pu have been investigated with GAMMASPHERE at ATLAS, using Coulomb excitation with a /sup 208/Pb beam at energies above the Coulomb barrier. Data on a transfer channel leading to /sup 242/Pu were obtained as well. In the case of /sup 244/Pu, the yrast band was extended to 34h(cross), revealing the completed pi i/sub 13/2/ alignment, a "first" for actinide nuclei. The yrast sequence of /sup 242/Pu was also extended to higher spin and a similar backbend was delineated. In contrast, while the ground state band of /sup 240/Pu was measured up to the highest rotational frequencies ever reported in the actinide region (~300 keV), no sign of particle alignment was observed. (11 refs).

  11. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    International Nuclear Information System (INIS)

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W.

    2013-01-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10 4 . This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20

  12. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W. [China Institute of Atomic Energy, P.O.Box 275(26), Beijing 102413 (China)

    2013-07-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10{sup 4}. This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20.

  13. Anomalous atomic volume of alpha-Pu

    DEFF Research Database (Denmark)

    Kollar, J.; Vitos, Levente; Skriver, Hans Lomholt

    1997-01-01

    We have performed full charge-density calculations for the equilibrium atomic volumes of the alpha-phase light actinide metals using the local density approximation (LDA) and the generalized gradient approximation (GGA). The average deviation between the experimental and the GGA atomic radii is 1.......3%. The comparison between the LDA and GGA results show that the anomalously large atomic volume of alpha-Pu relative to alpha-Np can be ascribed to exchange-correlation effects connected with the presence of low coordinated sites in the structure where the f electrons are close to the onset of localization...

  14. Study of U - Pu - Fe alloys (Masurca critical experiment)

    International Nuclear Information System (INIS)

    Barthelemy, P.; Boucher, R.

    1965-01-01

    Three compositions have been studied: 73.5 U - 25 Pu - 1.5 Fe (weight %) 74 U - 25 Pu - 1 Fe 74.5 U - 25 Pu - 0.5 Fe Elaboration and Casting are easy. After two weeks in air 74.5 U - 25 Pu - 0.5 Fe alloys are reduced in powder. As-cast alloys containing 1 and 1,5% Fe are kept undamaged during several months. A rapid oxidisation of the alloys is however observed when the samples undergo the phase transformation (at 595 deg. C and 590 deg. C respectively). Ignition tests in the presence of air show that the oxidisation starts at about 250 deg. C and that the reaction does not spread. Ignition is not observed during heating from 20 to 660 deg. C. The transformation temperature, the melting temperature and the thermal expansion coefficients have been determined by dilatometry. Below the transformation temperature, the principal phases are U-Pu zeta and (U, Pu) 6 Fe. Thermal conductibility, Young modulus, density and heat of fusion have been measured. Compatibility tests show that between U-Pu-Fe and stainless steel a phase of (U, Pu) 6 Fe type is formed. The 74 U - 25 Pu - 1% Fe alloy seems to behave better than 73.5 U - 25 Pu - 1.5% Fe alloy because the (U, Pu) 6 Fe layer is two or three times smaller. Finally, the thermal stability has been studied with the 74 U - 25 Pu - 1% Fe alloy. A dilatometric anomaly (very weak expansion) occurs when the sample is heated above transformation temperature and cooled. But there is no anomaly by thermal cycling from 50 deg. C to 400 deg. C and there is no deterioration of alloys by heat treatments at 100 deg. C, 200 deg. C, 300 deg. C during 5 months under vacuum. (authors) [fr

  15. Metal-carbide multilayers for molten Pu containment

    International Nuclear Information System (INIS)

    Summers, T.S.E.; Curtis, P.G.; Juntz, R.S.; Krueger, R.L.

    1991-12-01

    Multilayers composed of nine or ten alternating layers of Ta or W and TaC were studied for the feasibility of their use in containing molten plutonium (Pu) at 1200 degrees C. Single layers of W and TaC were also investigated. A two-source electron beam evaporation process was developed to deposit these coatings onto the inside surface of hemispherical Ta cups about 38 mm in diameter. Pu testing was done by melting Pu in the coated hemispherical cups and holding them under vacuum at 1200 degrees C for two hours. Metallographic examination and microprobe analysis of cross sections showed that Pu had penetrated to the Ta substrate in all cases to some extent. Full penetration to the outer surface of the Ta substrate, however, occurred in only a few of the samples. The fact that full penetration occurred in any of the samples suggests that it would have occurred in uncoated Ta under these testing conditions which in turn suggests that the multilayer coatings do afford some protection against Pu attack. The TaC used for these specimens was wet by Pu under these testing conditions, and following testing, Pu was found uniformly distributed throughout the carbide layers which appeared to be rather porous. Pu was seen in the W and Ta layers only when exposed directly to molten Pu during testing or near defects suggesting that Pu penetrated the multilayers at defects in the coating and traveled parallel to the layers along the carbide layers. These results indicate that the use of alternating metal and ceramic layers for Pu containment should be possible through the use of nonporous ceramic that is not wet by molten Pu and defect-free films

  16. Pu and Am determination in the environment method development

    International Nuclear Information System (INIS)

    Afonin, M.; Simonoff, M.; Donard, O.; Michel, H.; Ardisson, G.

    2002-01-01

    A few articles were published in the recent years regarding the application of ICP MS HR to the determination of ultratrace Pu in the environment. Si removal was not applied in recent publications. It is well known from marine biology that some microorganisms use Si derivatives in their metabolism. This implies that important amounts of Pu will not be dissolved and instead will rest in the solid residue. In our work we chose a combination of methods from EML-300 Handbook: Pu-02-RC Plutonium in Soil Samples, Pu-03-RC Plutonium in Soil Residue - Total Dissolution Method, Pu-11-RC Plutonium Purification - Ion Exchange Technique, Pu-12-RC Plutonium and/or Americium in Soil or Sediments. A high resolution inductively coupled plasma mass spectrometric method was developed for the determination of Am and the 240 Pu/ 239 Pu isotope ratio. The total plutonium concentrations ( 239+240 Pu) measured in environmental samples by this method were in good agreement with recommended data obtained from alpha-spectrometry. A reduction in the time of analysis over 33% was achieved

  17. Analytical description of transfer of Pu-239 in undisturbed soil

    Energy Technology Data Exchange (ETDEWEB)

    Tianshan, Ren; Linsalata, P; Cohen, N

    1986-04-01

    The paper reports on an analytical model for describing the horizontal and down-ward transfer of /sup 239/Pu in undisturbed soil based on observed data. The model has been developed to predict how the depth distribution of /sup 239/Pu in soil would change with time. This information is essential for estimation of the quantities of /sup 239/Pu that have entered surface water body via erosion and runoff processes and for estimation of the long-term impact of /sup 239/Pu isice the commencement of nuclear fallout deposition.

  18. Effect of equilibration time on Pu desorption from goethite

    International Nuclear Information System (INIS)

    Wong, Jennifer C.; Powell, Brian A.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.

    2015-01-01

    It has been suggested that strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time which has implications for near- and far-field transport of Pu. Batch adsorption-desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethite was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.

  19. Evaluation of containment failure and cleanup time for Pu shots on the Z machine.

    Energy Technology Data Exchange (ETDEWEB)

    Darby, John L.

    2010-02-01

    Between November 30 and December 11, 2009 an evaluation was performed of the probability of containment failure and the time for cleanup of contamination of the Z machine given failure, for plutonium (Pu) experiments on the Z machine at Sandia National Laboratories (SNL). Due to the unique nature of the problem, there is little quantitative information available for the likelihood of failure of containment components or for the time to cleanup. Information for the evaluation was obtained from Subject Matter Experts (SMEs) at the Z machine facility. The SMEs provided the State of Knowledge (SOK) for the evaluation. There is significant epistemic- or state of knowledge- uncertainty associated with the events that comprise both failure of containment and cleanup. To capture epistemic uncertainty and to allow the SMEs to reason at the fidelity of the SOK, we used the belief/plausibility measure of uncertainty for this evaluation. We quantified two variables: the probability that the Pu containment system fails given a shot on the Z machine, and the time to cleanup Pu contamination in the Z machine given failure of containment. We identified dominant contributors for both the time to cleanup and the probability of containment failure. These results will be used by SNL management to decide the course of action for conducting the Pu experiments on the Z machine.

  20. /sup 238/Pu fuel-form processes. Quarterly report, October-December 1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    Progress in the Savannah River /sup 238/Pu Fuel Form Program is summarized. Work during this period concentrated on the extensive cracking of the /sup 238/PuO/sub 2/ fuel form prior to encapsulation in the iridium containment shell for heat sources. This cracking results in increased recycle cost and decreased production efficiency. To better understand this cracking, Savannah River Laboratory (SRL) has made an extensive review of the development of /sup 238/PuO/sub 2/ fuel forms from small-scale Multi-hundred Watt (MHW) pellets through the current GPHS full-scale pellet production. Historically, /sup 238/PuO/sub 2/ fuel has almost always been uncracked after hot pressing in a graphite die, but has emerged cracked and fragile from the final heat-treatment furnace. The cracking tendency depends on the microstructure of the fuel form and on the hot pressing conditions used to fabricate it. In general, a microstructure of large intershard porosity is more desirable because it allows internal gas to escape more readily and it can absorb more reoxidation strain. Studies of the GPHS microstructure showed that the internal structures of typical GPHS Pellets fabricated at LANL and in the PEF differed significantly. The LANL pellets had severe density gradients and were extensively cracked.

  1. Determination of 241Pu by low level β-proportional counting

    International Nuclear Information System (INIS)

    Rosner, G.; Hoetzl, H.; Winkler, R.

    1992-01-01

    A chemical separation procedure is described which allows the direct determination of low 241 Pu activities in environmental samples with a windowless gas-flow proportional counter. While current separation schemes based on anion exchange yield counting sources of sufficient purity for subsequent α-spectrometry, for β-counting of 241 Pu additional purification steps are required. A combination of anion exchange from 9 mol/1 HCl, LaF 3 precipitation and TTA extraction was found to be suitable even for analysis of long-range Chernobyl fallout samples which contained interfering radionuclides with β-activities at least 3 to 4 orders of magnitude higher than usually encountered. No difference is detectable between the results of the present, direct procedure and the results of the conventional indirect method based on the build-up of 241 Am. Average 241 Pu/ 239+241 Pu ratios in air and deposition samples taken at Neuherberg near Munich were 70±6 with the present procedure and 66±9 from 241 Am build-up. (author) 29 refs.; 3 tabs

  2. Electrolysis of plutonium in neutral and basic solutions

    International Nuclear Information System (INIS)

    1978-01-01

    Experiments were conducted on electrolysis of Pu in waste streams. Removal of Pu by this process is maximum at pH 11. Runs on an actual waste stream showed that: Pu can be electrolyzed from neutral or basic solutions down to 10 -10 g/l. Am can also be removed. The removal efficiency is pH dependent. The deposits can be removed by acid leaching

  3. HANFORD Pu-238 DRUM INTEGRITY ASSESSMENT

    International Nuclear Information System (INIS)

    CANNELL, G.R.

    2004-01-01

    Hanford is presently retrieving contact-handled, transuranic (CH-TRU) waste drums from the site's Low-Level Burial Grounds (LLBG) for processing and disposition. A subgroup of these drums (12 total), referred to as Pu-238 drums, has some unique characteristics that may impact the current drum handling and processing activities. These characteristics include content, shielding, thermal, pressurization and criticality issues. An effort to evaluate these characteristics, for the purpose of developing a specific plan for safe retrieval of the Pu-238 drums, is underway. In addition to the above evaluation, the following integrity assessment of the inner container material and/or confinement properties, with primary emphasis on the Source Capsule (primary confinement barrier) and Shipping Container has been performed. Assessment included review of the inner container materials and the potential impact the service history may have had on material and/or confinement properties. Several environmental degradation mechanisms were considered with the objective of answering the following question: Is it likely the container material and/or confinement properties have been significantly altered as a result of service history?

  4. Detailed spectroscopy in the superdeformed second minimum of 240Pu

    International Nuclear Information System (INIS)

    Thirolf, P.G.; Gassmann, D.; Habs, D.; Chromik, M.J.; Eisermann, Y.; Graw, G.; Hertenberger, R.; Maier, H.J.; Metz, A.; Reiter, P.

    2000-01-01

    Complete text of publication follows. Superdeformed prolate nuclei, having an axis ratio of about 2:1, have first been discovered in fission isomers in the actinide region almost 40 years ago by Polikanov et al.. Their interpretation of being the result of microscopic shell corrections on top of the macroscopic liquid drop potential leading to a second minimum in the nuclear potential energy surface is well established. 240 Pu with its 3.7 ns fission isomer may be regarded as the prototype nucleus for spectroscopic studies of superdeformed actinide nuclei since the identification of the ground state rotational band in conversion electron measurements [1]. Though from the knowledge on excited states in the first minimum and previous measurements in the second minimum low-lying collective excitations in the second minimum low-lying collective excitations in the second well of 240 Pu can be expected, none of them has been experimentally identified so far. Quite surprisingly, no low-lying collective quadrupole excitations could be observed in a recent detailed high-resolution and high-efficiency γ-spectroscopy experiment [2]. Complementary information could be obtained in conversion electron measurements in coincidence with isomeric fission performed at the Garching Accelerator Laboratory, resulting in the first identification of the lowest β-vibrational band [3]. In a combined analysis of the γ-spectroscopic and conversion electron data conversion coefficients α K or limits on α K could be deduced, thus allowing to determine the multipolarities of the transitions. A predominant population of negative parity states in the second well could be observed that can be explained by the filtering function of the inner and outer fission barrier. Complementary transmission resonance measurements have been performed, yielding new information on the fine structure of (β-)vibrational multi-phonon states. A new method could be established to determine the excitation energy of

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

    DEFF Research Database (Denmark)

    Eriksson, Mats; Lindahl, Patric; Roos, Per

    2008-01-01

    ). In the five hot particles examined, the measured uranium atomic ratio was U-235/U-238 = 1.02 +/- 0.16 and the Pu-isotopic ratios were as follows: Pu-240/Pu-239 0.0551 +/- 0.0008 (atom ratio), Pu-238/Pu239+240 = 0.0161 +/- 0.0005 (activity ratio), Pu-241/Pu239+240 = 0.87 +/- 0.12 (activity ratio), and Am-241...... than one Pu source involved in the accident, confirming earlier studies. The Pu-238/Pu239+240 activity ratio and the Pu-240/Pu-239 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 (Pu-238/Pu239+240 activity ratio similar to 0.01 and the Pu-240/Pu-239 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...

  6. Solubility of reactor fuels in the mouse lung with respect to their U/Pu and 238Pu/239Pu ratios

    International Nuclear Information System (INIS)

    Talbot, R.J.; Baker, S.T.

    1989-01-01

    The studies reported were designed to assess the comparative in vivo solubilities of a range of plutonium containing reactor fuels. To simulate these fuels, mixed U/Pu oxides were prepared and calcined at 1600 0 C. A plutonium content of 3% w/w was chosen as typical of water-cooled reactor fuel. Higher concentrations of plutonium (10, 20 and 30%) were included to simulate fast reactor fuel. As it is known that 238 PuO 2 , with high specific activity, is translocated more rapidly from lung than 239 PuO 2 , the effect of isotopic composition of plutonium in simulated reactor fuels was also investigated. For this purpose, both the water-cooled and fast-reactor fuels were prepared with plutonium containing 2% of 238 Pu by weight. The resulting oxides had about 6 times the specific activity of those prepared with 239 Pu. Groups of mice were killed at 1, 3, 6, 12 and 18 months after inhaling aerosols of the simulated reactor fuels. After 3 months, measurements of Pu retention in the lung showed no marked differences between materials. After 6 months, measurements of plutonium deposited in the liver and skeleton showed that mixed U/Pu oxides were more soluble in vivo than 239 PuO 2 . Their solubility was inversely related to their plutonium content. The addition of 238 Pu to the plutonium resulted in enhanced translocation of plutonium from the lung, in the cases of water-cooled reactor fuel by a factor of two. (author)

  7. Kinetics of the high temperature oxygen exchange reaction on {sup 238}PuO{sub 2} powder

    Energy Technology Data Exchange (ETDEWEB)

    Whiting, Christofer E., E-mail: chris.whiting@udri.udayton.edu [University of Dayton – Research Institute, 300 College Park, Dayton, OH 45469-0172 (United States); Du, Miting; Felker, L. Kevin; Wham, Robert M. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Barklay, Chadwick D.; Kramer, Daniel P. [University of Dayton – Research Institute, 300 College Park, Dayton, OH 45469-0172 (United States)

    2015-12-15

    Oxygen exchange reactions performed on PuO{sub 2} suggest the reaction is influenced by at least three mechanisms: an internal chemical reaction, surface mobility of active species/defects, and surface exchange of gaseous oxygen with lattice oxygen. Activation energies for the surface mobility and internal chemical reaction are presented. Determining which mechanism is dominant appears to be a complex function including at least specific surface area and temperature. Thermal exposure may also impact the oxygen exchange reaction by causing reductions in the specific surface area of PuO{sub 2}. Previous CeO{sub 2} surrogate studies exhibit similar behavior, confirming that CeO{sub 2} is a good qualitative surrogate for PuO{sub 2}, in regards to the oxygen exchange reaction. Comparison of results presented here with previous work on the PuO{sub 2} oxygen exchange reaction allows complexities in the previous work to be explained. These explanations allowed new conclusions to be drawn, many of which confirm the conclusions presented here. - Highlights: • PuO{sub 2} Oxygen exchange kinetics can be influenced by at least 3 different mechanisms. • An internal chemical reaction controls the rate at high temperature and large SSA. • Surface mobility and surface exchange influence rate at lower temperatures and SSA. • Exchange temperatures may alter SSA and make data difficult to interpret.

  8. 242Pu as tracer for simultaneous determination of 237Np and 239,240Pu in environmental samples

    DEFF Research Database (Denmark)

    Chen, Q.J.; Dahlgaard, H.; Nielsen, S.P.

    2002-01-01

    A procedure has been developed using Pu-242 as tracer for simultaneous determination of Np-237 and Pu-239,Pu-240 in environmental samples. The validity of the method has been demonstrated by ICPMS and alpha-spectroscopy for up to 10 gram soil and sediment, seawater up to 200 litres. The paper...... from Np and Pu) R-before/R-after = 1.004 +/- 3.3% (S.D n = 20) and 1 litre seawater R-before/R-after = 1.019+/-1.9% (S.D., n = 12). Results from the intercomparison samples LAEA-135, LAEA-381 and from environmental samples are presented....... describes a suitable chemical procedure for Np and Pu including a quantitative pre-concentration of neptunium and plutonium, preparation of Np4+ and Pu4+, NP(NO3)(6)(2-) and Pu(NO3)(6)(2-), The ratio of Np-237/Pu-242 (or Np-237/Pu-239) before and after the procedure has been determined using 10 g soil (free...

  9. Review of the thermodynamics of the U--C, Pu--C, and U--Pu--C systems

    International Nuclear Information System (INIS)

    Tetenbaum, M.; Sheth, A.; Olson, W.

    1975-06-01

    Thermodynamic properties such as enthalpy, heat capacity, entropy, heat and free energy of formation, and vaporization behavior are presented for the U--C, Pu--C, and U--Pu--C systems. These properties are of interest to scientists and engineers involved in the expanding field of advanced fuel LMFBR systems. The information on these systems has been derived largely from the discussions of the IAEA Panel on the assessment of thermodynamic properties of the U--C, Pu--C, and U--Pu--C systems. (U.S.)

  10. Trading sulfur dioxide allowances

    International Nuclear Information System (INIS)

    Goldburg, C.B.; Lave, L.B.

    1992-01-01

    The 1990 Clean Air Act is aimed at generators larger than 25 MW, as these are the largest polluters. Market incentives give each source an emissions allocation but also flexibility. If a plant has lower emissions than the target, it can sell the 'surplus' emissions as allowances to plants that fail to meet the target. Only a few trades have occurred to date. Market-based incentives should lower the costs of improving environmental quality significantly. However, currently institutional dificulties hamper implementation

  11. Evaluation of fission cross sections and covariances for {sup 233}U, {sup 235}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Matsunobu, Hiroyuki [Data Engineering, Inc. (Japan); Murata, Toru [AITEL Corporation, Tokyo (JP)] [and others

    2000-02-01

    A simultaneous evaluation code SOK (Simultaneous evaluation on KALMAN) has been developed, which is a least-squares fitting program to absolute and relative measurements. The SOK code was employed to evaluate the fission cross sections of {sup 233}U, {sup 235}U, {sup 238}U, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu for the evaluated nuclear data library JENDL-3.3. Procedures of the simultaneous evaluation and the experimental database of the fission cross sections are described. The fission cross sections obtained were compared with evaluated values given in JENDL-3.2 and ENDF/B-VI. (author)

  12. Evaluation of fission cross sections and covariances for 233U, 235U, 238U, 239Pu, 240Pu, and 241Pu

    International Nuclear Information System (INIS)

    Kawano, Toshihiko; Matsunobu, Hiroyuki; Murata, Toru

    2000-02-01

    A simultaneous evaluation code SOK (Simultaneous evaluation on KALMAN) has been developed, which is a least-squares fitting program to absolute and relative measurements. The SOK code was employed to evaluate the fission cross sections of 233 U, 235 U, 238 U, 239 Pu, 240 Pu, and 241 Pu for the evaluated nuclear data library JENDL-3.3. Procedures of the simultaneous evaluation and the experimental database of the fission cross sections are described. The fission cross sections obtained were compared with evaluated values given in JENDL-3.2 and ENDF/B-VI. (author)

  13. Data Evaluation of Actinide Cross Sections: 238Pu, 237Pu, and 236Pu

    Energy Technology Data Exchange (ETDEWEB)

    Guaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jurgenson, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, I. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ormand, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mattoon, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Beck, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bailey, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-04

    This report documents the recent evaluation of the 236Pu, 237Pu, and 238Pu cross section sets. Nuclear data evaluation is the fundamental interface that takes measured nuclear cross section data and turns them into a continuous curve that 1) is consistent with other measurements and nuclear reaction theory/models, and 2) is required by down-stream users. All experiments that generate nuclear data need to include an evaluation step for their data to be broadly useful to the end users.

  14. Analysis of the 239Pu neutron cross sections from 300 to 2000 eV

    International Nuclear Information System (INIS)

    Derrien, H.; de Saussure, G.

    1990-01-01

    A recent high-resolution measurement of the neutron fission cross section of 239 Pu has allowed the extension from 1 to 2 keV of a previously reported resonance analysis of the neutron cross sections, and an improvement of the previous analysis in the range 0.3 to 1 keV. This report analyzes this region. 8 refs., 1 fig., 2 tabs

  15. α spectrometry on thick sources. Application to Pu dosing in U-Pu alloys with a low Pu content

    International Nuclear Information System (INIS)

    Guery, Marcel

    1969-06-01

    After having noticed that alpha spectrometry of thick sources has been not much studied, the author reports the application of this type of alpha spectrometry to a problem of plutonium dosing in uranium-plutonium alloys with low plutonium content. Four measurement and test campaigns, each being few month long, have been performed. During the first three ones, the best measurement conditions have been determined, the necessary apparatus has been acquired, and data compilation has been elaborated. This report addresses the last campaign during which exploitable results have been obtained. After some generalities about alpha rays from thick sources, the author reports a detailed examination of measurements made on U-Pu alloys, and of corrections to be made, notably those due to the Am-241 content, to stacking and to oxidation. The method appears to be very sensitive, with a precision better than 1 per cent. Improvements seem possible [fr

  16. Transfer of 241Am and 237Pu from euphausiid moults to a carbonate-rich marine sediment

    International Nuclear Information System (INIS)

    Hargrave, B.T.

    1986-01-01

    Concentrations of 241 Am and 237 Pu adsorbed onto moulted exoskeletons from the euphausiid Meganyctiphanes norvegica decreased exponentially with 50% retention times of 3-7 d when moults were incubated in filtered seawater with small amounts of carbonate-rich sediment. Over 95% of sediment weight was present as -2 ) was greatest in the medium-fine sand fraction which had the highest carbonate content. These particles constituted -2 surface: atoms μm -3 in solution) was 10 3 -10 4 times higher than similar quotients for 241 Am and 237 Pu sorbed to surfaces of organic particles are transferred to sediments. (author)

  17. Photometric estimation of plutonium in product solutions and acid waste solutions using flow injection analysis technique

    International Nuclear Information System (INIS)

    Dhas, A.J.A.; Dharmapurikar, G.R.; Kumaraguru, K.; Vijayan, K.; Kapoor, S.C.; Ramanujam, A.

    1995-01-01

    Flow injection analysis technique is employed for the measurement of plutonium concentrations in product nitrate solutions by measuring the absorbance of Pu(III) at 565 nm and of Pu(IV) at 470 nm, using a Metrohm 662 photometer, with a pyrex glass tube of 2 nm (ID) inserted in the light path of the detector serving as a flow cell. The photometer detector never comes in contact with radioactive solution. In the case of acid waste solutions Pu is first purified by extraction chromatography with 2-ethyl hexyl hydrogen 2 ethyl hexyl phosphonate (KSM 17)- chromosorb and the Pu in the eluate in complexed with Arsenazo III followed by the measured of absorbance at 665 nm. Absorbance of reference solutions in the desired concentration ranges are measured to calibrate the system. The results obtained agree with the reference values within ±2.0%. (author). 3 refs., 1 tab

  18. PU.1 silencing leads to terminal differentiation of erythroleukemia cells

    International Nuclear Information System (INIS)

    Atar, Orna; Levi, Ben-Zion

    2005-01-01

    The transcription factor PU.1 plays a central role in development and differentiation of hematopoietic cells. Evidence from PU.1 knockout mice indicates a pivotal role for PU.1 in myeloid lineage and B-lymphocyte development. In addition, PU.1 is a key player in the development of Friend erythroleukemia disease, which is characterized by proliferation and differentiation arrest of proerythrocytes. To study the role of PU.1 in erythroleukemia, we have used murine erythroleukemia cells, isolated from Friend virus-infected mice. Expression of PU.1 small interfering RNA in these cells led to significant inhibition of PU.1 levels. This was accompanied by inhibition of proliferation and restoration in the ability of the proerythroblastic cells to produce hemoglobin, i.e., reversion of the leukemic phenotype. The data suggest that overexpression of PU.1 gene is the immediate cause for maintaining the leukemic phenotype of the disease by retaining the self-renewal capacity of transformed erythroblastic cells and by blocking the terminal differentiation program towards erythrocytes

  19. Structure and potential energy function for Pu22+ ion

    International Nuclear Information System (INIS)

    Li Quan; Huang Hui; Li Daohua

    2003-01-01

    The theoretical study on Pu 2 2+ using density functional method shows that the molecular ion is metastable. Ground electronic state is 13 Σ g for Pu 2 2+ , the analytic potential energy function is in well agreement with the Z-W function, and the force constants and spectroscopic data have been worked out for the first time

  20. Np Analysis in IAT-Samples Containing <10 Microgram Pu

    International Nuclear Information System (INIS)

    Ludwig, R.; Raab, W.; Dashdondog, J.; Balsley, S.

    2008-01-01

    A method for the determination of neptunium to plutonium in safeguards samples containing less than 10 microgram Pu is presented. The chemical treatment and the optimized measurement conditions for gamma spectrometry are reported. This method is based on thermal ionization mass spectrometry (TIMS) after chemical treatment and separation and was validated with mixtures of U, Pu and Np certified reference materials and using the 237 Np standard addition method, followed by separation of the waste fraction and gamma spectrometric analysis. The highest sensitivity, precision and accuracy in the determination of the Np:Pu ratio at microgram levels of Pu is achieved by evaluating 241 Pu and 233 Pa after measuring the adsorbent with a well-type gamma detector 3 weeks after chemical treatment. The repeatability of determining the Np:Pu ratio is estimated to be 5%, the maximum uncertainty as determined from comparing the 4 measurement modes is within ± 10% for samples containing 3 μg Pu, while being within ± 20% for 0.4 μg Pu. (authors)

  1. Savannah River Laboratory monthly report: 238Pu fuel form processes

    International Nuclear Information System (INIS)

    1976-01-01

    Progress in the Savannah River 238 Pu Fuel Form Program is discussed. Goals of the Savannah River Laboratory (SRL) program are to provide technical support for the transfer of the 238 Pu fuel form fabrication operations from Mound Laboratory to new facilities being built at the Savannah River Plant (SRP), to provide the technical basis for 238 Pu scrap recovery at SRP, and to assist in sustaining plant operations. During the period it was found that the density of hot-pressed 238 PuO 2 pellets decreased as the particle size of ball-milled powder decreased;the surface area of calcined 238 PuO 2 powder increased with increasing precipitation temperature and may be related to the variation in ball-milling response observed among different H Area B-Line batches; calcined PuO 2 produced by Pu(III) reverse-strike precipitation was directly fabricated into a pellet without ball milling, slugging, or sharding. The pellet had good appearance with acceptable density and dimensional stability, and heat transfer measurements and calculations showed that the use of hollow aluminum sleeves in the plutonium fuel fabrication (PuFF) storage vault reduced the temperature of shipping cans to 170 0 C and will reduce the temperature at the center of pure plutonium oxide (PPO) spheres to 580 0 C

  2. Np Analysis in IAT-Samples Containing <10 Microgram Pu

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, R.; Raab, W.; Dashdondog, J.; Balsley, S. [IAEA, Safeguards Analytical Laboratory, Wagramer Str. 5, P.O. Box 100, A-1400 Vienna (Austria)

    2008-07-01

    A method for the determination of neptunium to plutonium in safeguards samples containing less than 10 microgram Pu is presented. The chemical treatment and the optimized measurement conditions for gamma spectrometry are reported. This method is based on thermal ionization mass spectrometry (TIMS) after chemical treatment and separation and was validated with mixtures of U, Pu and Np certified reference materials and using the {sup 237}Np standard addition method, followed by separation of the waste fraction and gamma spectrometric analysis. The highest sensitivity, precision and accuracy in the determination of the Np:Pu ratio at microgram levels of Pu is achieved by evaluating {sup 241}Pu and {sup 233}Pa after measuring the adsorbent with a well-type gamma detector 3 weeks after chemical treatment. The repeatability of determining the Np:Pu ratio is estimated to be 5%, the maximum uncertainty as determined from comparing the 4 measurement modes is within {+-} 10% for samples containing 3 {mu}g Pu, while being within {+-} 20% for 0.4 {mu}g Pu. (authors)

  3. Preparation, microstructures, and properties of PuO2

    International Nuclear Information System (INIS)

    Bickford, D.F.; Rankin, D.T.; Smith, P.K.

    1976-01-01

    PuO 2 pellets with controlled microstructures were fabricated to meet operational requirements for packaged heat sources. Size distributions, morphologies (forms and structures), and packing densities were measured on calcined and milled powders, slugged compacts, and presintered granules. These variables influence microstructure, porosity distribution, and fracture behavior of hot-pressed and sintered PuO 2

  4. Nuclear characteristics of Pu fueled LWR and cross section sensitivities

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Toshikazu [Osaka Univ., Suita (Japan). Faculty of Engineering

    1998-03-01

    The present status of Pu utilization to thermal reactors in Japan, nuclear characteristics and topics and cross section sensitivities for analysis of Pu fueled thermal reactors are described. As topics we will discuss the spatial self-shielding effect on the Doppler reactivity effect and the cross section sensitivities with the JENDL-3.1 and 3.2 libraries. (author)

  5. Complexation studies of actinides (U, Pu, Am) with linear polyamino-carboxylate ligands and sidero-chelates

    International Nuclear Information System (INIS)

    Nguyen, L.V.

    2010-01-01

    As part of our research endeavour aimed at developing and improving decontamination processes of wastewater containing alpha emitters, physico-chemical complexation studies of actinides (U, Pu, Am) with organic open-chain ligands such as poly-aminocarboxylic acids (H 4 EDTA) and sidero-chelates (di-hydroxamic acids and desferrioxamine B) have been carried out. Gaining a clear understanding of the coordination properties of the targeted actinides is an essential step towards the selection of the most appropriate chelating agents that will exhibit high uptake efficiencies. EXAFS (Extended X-ray Absorption Fine Structure) measurements at the ESRF synchrotron enabled to elucidate the coordination scheme of uranium and plutonium complexes. Solution thermodynamic investigations were intended to provide valuable information about the nature and the stability of the uranium(VI) and americium(III) complexes prevailing at a given pH in solution. The set of stability constants determined from potentiometric and UV-visible spectrophotometric titrations, allowed to predict the speciation of the selected actinides in presence of the aforementioned ligands and to determine the pH range required for achieving 'ultimate' decontamination. (author) [fr

  6. Modification of analytical method for measurement of 239Pu, 240Pu and 241Am in sediment and sea water

    International Nuclear Information System (INIS)

    Syarbaini; Tarigan, C.; Rustam, M.F.

    1997-01-01

    Modification of analytical method for measurement of 239 Pu, 240 Pu and 241 Am in sediment and sea water have been conducted. This study is to develop a method for separation of 239 Pu, 240 Pu and 241 Am from 100-300 g of sediment and 100-200 l of sea water samples. Most of the methods described in the literature are to separation of '2 39 Pu, '2 40 Pu and 241 Am from 20-50 g of sediment and 30-100 l of sea water samples. By this method, 239,240 Pu and 241 Am were concentrated using the coprecipitation of CaC 2 O 4 and Fe (OH) 3 . Plutonium-242 and Curium-244 were used as tracer to determine chemical recovery. The result of analysis of some sediment samples showed that the chemical recoveries were respectively obtained in the range of 59.7 to 72.6% with average of 66.2 % for 242 Pu and 72.0 % to 85.5 % with average 78.8 % for 244 Cm. Analysis of some sea water samples were obtained in the range of 67 % to 78 % with average 73.9 % for 242 Pu and 74.0 % to 90.0 % with average 84.2 % for '2 42 Cm. This method was tested by the IAEA marine sediment, the result was excellent agreement with the IAEA certified sediment. It could be suggested that the developed analytical method is suitable to analyze the low level 239 Pu, 240 Pu and 241 Am in sediment and sea water samples (author)

  7. Sorption of Pu onto some kinds of clay

    International Nuclear Information System (INIS)

    Jia Haihong; Si Gaohua; Liu Wei; Yu Jing

    2010-01-01

    There are rich clay mines holding in one area, so it's necessary to know about these clays' sorption capacity to Pu, for building radioactive waste repository in the area. Distribution coefficients of Pu onto different clays were acquired in static method, with the result about 104. The size of clay is different, but the result of Kds is near. In addition, it's estimated how far Pu moves in the most rapid speed in the clay based on these Kids', disregarding the influence of Pu-colloid. In a word, as a kind of backfilling material clays in the area can effectively prevent Pu from moving to environment, and when designing the backfilling layer, it's not necessary to catch clays through NO.200 sieve, if only considering the influence of Kd. (authors)

  8. 239Pu standards for quantitative neutron-induced autoradiography

    International Nuclear Information System (INIS)

    Smith, J.M.; Atherton, D.R.; Wronski, T.J.; Jee, W.S.S.

    1977-01-01

    The present study deals with the preparation of 239 Pu standards for neutron bone tissue autoradiography and the calibration of these standards with respect to uranium reference standards. Known concentrations of 239 Pu were prepared in methyl methacrylate and Bioplastic casting resin bars. Wafers sawed from these bars served as standards. Solid state nuclear tract detectors (Lexan polycarbonate) were used to record fission fragment tracks after the standards were exposed to a thermal neutron flux. The original bars were found to contain a uniform distribution of 239 Pu. To confirm the concentration of 239 Pu in the wafers, the induced track density from the 239 Pu standards was compared with that from uranium reference standards. The average fission fragment detection efficiency for all of the standards was 0.51

  9. Deposition of 239Pu in the skeleton and soft tissues of beagles: effect of age at time of injection

    International Nuclear Information System (INIS)

    Stevens, W.; Atherton, D.R.; Bates, D.; Bruenger, F.W.

    1976-01-01

    Previous reports from the laboratory have clearly defined the whole body deposition of 239 Pu in beagles injected as young adults (18 mo.). However, deposition has not been evaluated as a function of skeletal maturity at the time of injection. Juvenile beagles 3 months of age were injected with 0.1 μCi 239 Pu/kg in 0.08 M citrate buffer, pH 3.5. Six of these beagles have been sacrificed at short times after injection for distribution data. Another group receiving 3.0 μCi 239 Pu/kg was allowed to live until osteosarcoma developed and they were autopsied (1228 days average). Finally an aged beagle (81 mo.) was injected with 0.1 μCi/kg plutonium (P 2.0) and sacrificed 2 weeks later. Selected soft tissues, 1/2 of the symmetrical skeleton, and a known fraction of the asymmetrical skeleton were collected and analyzed for Pu content. Independent of the age at injection, a total of approximately 80 percent of the Pu was initially deposited in liver plus skeleton, however the age of the animal at time of injection altered the relative proportion in liver and skeleton in a reciprocal manner. The percent of the injected Pu found in the liver at 14 days P.I. increased with the increase in age at time of injection (13.2 percent at 3 months, 30.9 percent at 18 months and 36.9 percent at 81 months). The lower the age at injection, the larger was the fraction of 239 Pu deposited in the skeleton. The amounts ranged from an average of 69 percent in animals injected at 3 months to 49 percent in dogs injected at 18 months and 40 percent in the dog injected at 81 months of age. The difference in skeletal deposition reflects the different rates of bone growth and remodeling in juveniles, young adults and aged beagles

  10. The Kuwano peculiar object (PU Vulpeculae)

    International Nuclear Information System (INIS)

    Belyakina, T.S.; Gershberg, R.E.; Efimov, Yu.S.; Krasnobabtsev, V.I.; Pavlenko, E.P.; Petrov, P.P.; Chuvaev, K.K.; Shenavrin, V.I.

    1982-01-01

    U, B, V, J, H, K photometry, polarimetry and spectroscopy of this peculiar object was made from August 1979 to December 1980 and the observations are briefly discussed. The authors consider PU Vul to be binary with a late M giant and a component of probably low luminosity. The latter flared in 1979, and the former also changed a little. From the photometric, spectroscopic and polarimetric data they estimate E(B-V) <= 0.4 and locate the star at 5-7 kpc from the sun and 0.7-1.0 kpc from the galactic plane. The photometric behaviour, duplicity, and nature of the components are similar to those of novae and symbiotic stars, but no evidence for an ejected envelope is seen. (Auth.)

  11. Photonuclear data evaluation of 239Pu

    International Nuclear Information System (INIS)

    Raskinyte, I.; Dupont, E.; Ridikas, D.

    2006-01-01

    This document presents cross-section calculations up to 130 MeV for Pu 239 using the Talys-0.64 code. The photoabsorption process is described by the giant dipole resonance and quasi-deuteron mechanisms. Preequilibrium particle emission is treated with the classical exciton model. At equilibrium, the compound nucleus decay channels are handled within the Hauser-Feshbach statistical model. Neutron transmission coefficients are calculated with a double humped parabolic model. A few sensitive nuclear parameters were fine-tuned to better reproduce the experimental data available for (γ,n), (γ,2n) and (γ,f) partial cross-sections. In addition, the nuclear models provide predictions of the emitted neutron energy and angular distributions. (A.C.)

  12. A Composite Light Curve Model of the Symbiotic Nova PU Vul (1979

    Directory of Open Access Journals (Sweden)

    Kato M.

    2012-06-01

    Full Text Available PU Vul (1979 is a symbiotic nova that shows a long-lasting flat optical peak followed by a slow decline. We made a quasi-evolution model for outbursts on a 0.6 M⊙ white dwarf consisting of a series of static solutions with optically-thin winds. Our theoretical models reproduce well the observed visual/UV light curves as well as the new estimates of the temperature and radius of the hot component. We also modeled the light curve of the 1980 and 1994 eclipses as the total eclipse occulted by a pulsating M-giant companion star. In the second eclipse, the visual magnitude is dominated by nebular emission which is possibly ejected from the hot component between 1990 to 2000. We have quantitatively estimated three components of emission, i.e., the white dwarf, companion and nebular, and made a composite light curve that represents well the evolution of the PU Vul outburst.

  13. Chemical speciation of 239240Pu and 137Cs in Lake Michigan waters

    International Nuclear Information System (INIS)

    Alberts, J.J.; Wahlgren, M.A.; Jehn, P.J.; Nelson, D.M.; Orlandini, K.A.

    1974-01-01

    Studies of the submicron size distribution and charge characteristics of naturally occurring levels of 239 Pu, 240 Pu, and 137 Cs were conducted to help define the physico-chemical state of these fallout derived nuclides in Lake Michigan waters and in precipitation samples taken in the Argonne Laboratory area. Procedures are described for sample collection, size distribution determination, analysis of ion exchange resins, and plutonium determination by evaporation. Results indicated that the radioisotopes exist in several different fractions within the water column and that the total charge of these fractions is different from what would be predicted by simple solution chemistry. The distribution of the isotopes in snow appears to be different from that in the water column, indicating that considerable chemical or physical transformations must take place after the atomospheric input has reached the lake surface

  14. The moisture content monitoring device for PuO2 using self neutron radiation

    International Nuclear Information System (INIS)

    Bulanenko, Valeriy I.; Sviridov, Victor; Frolov, Vladimir V.; Ryazanov, Boris G.; Talanov, Vladimir V.

    2003-01-01

    Solutions technology of plutonium dioxide powders production inevitably leads to free or chemically bound hydrogen to be present in these powders. This work is devoted to the nondestructive method of PuO 2 powder moisture measurement based on application of the effect of neutron moderation caused by water. Plutonium dioxide is fast neutron source, while 3 He counters located in the nickel and polyethylene annular reflectors surrounding PuO 2 serve as detectors. In the work wide range of issues are considered related to practical implementation of the moisture measurement method by detecting inherent neutron radiation of plutonium dioxide powder. The most practical design of the detector has been chosen, which include two 3 He detectors having different reflectors mounted to the device. The absolute error of measurement does not exceed 0.2wt% with confidence coefficient of 0.95. Duration of analysis ∼5 minutes. (author)

  15. Evaluations of Mechanisms for Pu Uptake and Retention within Spherical Resorcinol-Formaldehyde Resin Columns

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Levitskaia, Tatiana G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-15

    The unexpected uptake and retention of plutonium (Pu) onto columns containing spherical resorcinol-formaldehyde (sRF) resin during ion exchange testing of Cs (Cs) removal from alkaline tank waste was observed in experiments at both the Pacific Northwest National Laboratory (PNNL) and the Savannah River National Laboratory (SRNL). These observations have raised concern regarding the criticality safety of the Cs removal unit operation within the low-activity waste pretreatment system (LAWPS). Accordingly, studies have been initiated at Washington River Protection Solutions (WRPS), who manages the operations of the Hanford Site tank farms, including the LAWPS, PNNL, and elsewhere to investigate these findings. As part of these efforts, PNNL has prepared the present report to summarize the laboratory testing observations, evaluate these phenomena in light of published and unpublished technical information, and outline future laboratory testing, as deemed appropriate based on the literature studies, with the goal to elucidate the mechanisms for the observed Pu uptake and retention.

  16. The evaluation of the mass distribution data for 238U, 239Pu and 242Pu fission

    International Nuclear Information System (INIS)

    Liu Tingjin

    2002-01-01

    The mass distribution data for 238 U at E n =1.5, 5.5, 8.3, 11.3, 14.9, 22.0, 27.5, 50.0, 99.5, 160.0 MeV, E p =20.0, 60.0 MeV 239 Pu at E n =0.17, 7.9, 14.5 MeV and 242 Pu at E n =15.1 MeV were evaluated and recommended based on the main available experimental data up to now. The experimental data were make necessary corrections and their errors were also made necessary adjustments. The problems concerned were discussed

  17. Distinguishing Pu Metal from Pu Oxide and Determining alpha-ratio using Fast Neutron Counting

    Energy Technology Data Exchange (ETDEWEB)

    Verbeke, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chapline, G. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nakae, L. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Prasad, M. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheets, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, N. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-07

    We describe a new method for determining the ratio of the rate of (α, n) source neutrons to the rate of spontaneous fission neutrons, the so called α-ratio. This method is made possible by fast neutron counting with liquid scintillator detectors, which can determine the shape of the fast neutron spectrum. The method utilizes the spectral difference between fission spectrum neutrons from Pu metal and the spectrum of (α, n) neutrons from PuO2. Our method is a generalization of the Cifarelli-Hage method for determining keff for fissile assemblies, and also simultaneously determines keff along with the α-ratio.

  18. Pu-238 Supply Program Project Execution Plan

    International Nuclear Information System (INIS)

    Wham, Robert M.; Martin, Sherman

    2012-01-01

    This Pu-238 Supply Program Project Execution Plan (PEP) summarizes critical information and processes necessary to manage the program. The PEP is the primary agreement regarding planning and objectives between The Department of Energy Office of Nuclear Energy (DOE NE-75), Oak Ridge National Laboratory Site Office (OSO) and the Oak Ridge National Laboratory (ORNL). The acquisition executive (AE) will approve the PEP. The PEP is a living document that will be reviewed and revised periodically until the project is complete. The purpose of the project is to reestablish the capability to produce plutonium-238 (Pu-238) domestically. This capability consists primarily of procedures, processes, and design information, not capital assets. As such, the project is not subject to the requirements of DOE O 413.3B, but it will be managed using the project management principles and best practices defined there. It is likely that some capital asset will need to be acquired to complete tasks within the project. As these are identified, project controls and related processes will be updated as necessary. Because the project at its initiation was envisioned to require significant capital assets, Critical Decision 0 (CD-0) was conducted in accordance with DOE O 413.3B, and the mission need was approved on December 9, 2003, by William Magwood IV, director of the Office of Nuclear Energy (NE), Science and Technology, DOE. No date was provided for project start-up at that time. This PEP is consistent with the strategy described in the June 2010 report to Congress, Start-up Plan for Plutonium-238 Production for Radioisotope Power Systems.

  19. Base case Pu-nitrate to Pu-oxide conversion plant

    International Nuclear Information System (INIS)

    1978-10-01

    This paper explains that the plutonium recovered in the course of reprocessing spent fuel is obtained in the form of plutonium nitrate, whereas PuO 2 is required for the fabrication of fuel rods. The reference conversion plant described in the paper converts plutonium nitrate into plutonium dioxide powder by precipitation with oxalic acid followed by calcination. The paper also describes the main features of the safety, maintenance and safeguards philosophy used in its design

  20. Internal Corrosion Analysis of Model 9975 Packaging Containing Pu or PuO2 During Shipping and Storage

    International Nuclear Information System (INIS)

    Vormelker, P.

    1999-01-01

    The Materials Consultation Group of SRTC has completed an internal corrosion analysis of the Model 9975 packaging assembly containing either Pu or PuO2 for storage in K Reactor under ambient conditions for a period of 12 years. The 12-year storage period includes two years for shipping and up to ten years for storage

  1. Extraction of plutonium and uranium from oxalate bearing solutions using phosphonic acid

    International Nuclear Information System (INIS)

    Godbole, A.G.; Mapara, P.M.; Swarup, Rajendra

    1995-01-01

    A feasibility study on the solvent extraction of plutonium and uranium from solutions containing oxalic and nitric acids using a phosphonic acid extractant (PC88A) was made to explore the possibility of recovering Pu from these solutions. Batch experiments on the extraction of Pu(IV) and U(VI) under different parameters were carried out using PC88A in dodecane. The results indicated that Pu could be extracted quantitatively by PC88A from these solutions. A good separation of Pu from U could be achieved at higher temperatures. (author). 6 refs., 3 tabs

  2. Removal of plutonium from nitric acid-oxalic acid solutions using anion exchange method

    International Nuclear Information System (INIS)

    Kasar, U.M.; Pawar, S.M.; Joshi, A.R.

    1999-01-01

    An anion exchange method using Amberlyst A-26 (MP) resin was developed for removal of Pu from nitric acid-oxalic acid solutions without destroying oxalate. The method consists of sorption of Pu(IV) on Amberlyst A-26, a macroporous anion exchange resin, from nitric acid-oxalic acid medium in the presence of Al(NO 3 ) 3 . Pu(IV) breakthrough capacity of Amberlyst A-26 using synthetic feed solution was determined. (author)

  3. Safety analysis report: packages. Pu oxide and Am oxide shipping cask (Packaging of fissile and other radioactive materials). Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1980-05-01

    The PuO 2 cask or SP 5320-2 and 3 cask is designed for surface shipment of americium or plutonium. The cask design was physically tested to demonstrate that it met the criteria specified in US ERDA Manual Chapter 0529, and Chapter I, Interstate Commerce Commission. The package has been assessed for transport of up to 357 grams of plutonium (403 grams PuO 2 powder) and up to 176 grams of americium (200 grams AmO 2 powder), having a maximum decay heat of 203 watts. Criticality evaluation alone would allow the shipment as Fissile Class II but the radiation level of the cask, measured at the time of shipment, may exceed 50 mrem/h at the surface and require shipment as Fissile Class III. Sample calculations address only the more restrictive of the two materials, which in most cases is 238 PuO 2

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

    International Nuclear Information System (INIS)

    Vega-Carrillo, H.R.; Manzanares-Acuna, Eduardo; Becerra-Ferreiro, A.M.; Carrillo-Nunez, Aureliano

    2002-01-01

    Neutron and gamma-ray spectra of 239 PuBe and 241 AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6 LiI(Eu) scintillator. The 239 PuBe neutron spectrum was measured in an open environment, while the 241 AmBe 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 241 AmBe 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

  5. Interception and retention of 238Pu deposition by orange trees

    International Nuclear Information System (INIS)

    Pinder, J.E. III; Adriano, D.C.; Ciravolo, T.G.; Doswell, A.C.; Yehling, D.M.

    1987-01-01

    Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of 238 Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse 238 Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of 238 Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of 238 Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the 238 Pu deposited onto an orange grove would be harvested in the year following deposition

  6. Optimal Bidding and Operation of a Power Plant with Solvent-Based Carbon Capture under a CO2 Allowance Market: A Solution with a Reinforcement Learning-Based Sarsa Temporal-Difference Algorithm

    Directory of Open Access Journals (Sweden)

    Ziang Li

    2017-04-01

    Full Text Available In this paper, a reinforcement learning (RL-based Sarsa temporal-difference (TD algorithm is applied to search for a unified bidding and operation strategy for a coal-fired power plant with monoethanolamine (MEA-based post-combustion carbon capture under different carbon dioxide (CO2 allowance market conditions. The objective of the decision maker for the power plant is to maximize the discounted cumulative profit during the power plant lifetime. Two constraints are considered for the objective formulation. Firstly, the tradeoff between the energy-intensive carbon capture and the electricity generation should be made under presumed fixed fuel consumption. Secondly, the CO2 allowances purchased from the CO2 allowance market should be approximately equal to the quantity of CO2 emission from power generation. Three case studies are demonstrated thereafter. In the first case, we show the convergence of the Sarsa TD algorithm and find a deterministic optimal bidding and operation strategy. In the second case, compared with the independently designed operation and bidding strategies discussed in most of the relevant literature, the Sarsa TD-based unified bidding and operation strategy with time-varying flexible market-oriented CO2 capture levels is demonstrated to help the power plant decision maker gain a higher discounted cumulative profit. In the third case, a competitor operating another power plant identical to the preceding plant is considered under the same CO2 allowance market. The competitor also has carbon capture facilities but applies a different strategy to earn profits. The discounted cumulative profits of the two power plants are then compared, thus exhibiting the competitiveness of the power plant that is using the unified bidding and operation strategy explored by the Sarsa TD algorithm.

  7. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Migliori, Albert [Los Alamos National Laboratory; Betts, J [Los Alamos National Laboratory; Trugman, A [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Mitchell, J N [Los Alamos National Laboratory; Ramos, M [Los Alamos National Laboratory; Stroe, I [WORXESTER, MA

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  8. 40 CFR 35.2025 - Allowance and advance of allowance.

    Science.gov (United States)

    2010-07-01

    ... advance of allowance. (a) Allowance. Step 2+3 and Step 3 grant agreements will include an allowance for facilities planning and design of the project and Step 7 agreements will include an allowance for facility... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allowance and advance of allowance. 35...

  9. Chemical behaviour of plutonium in aqueous chloride solutions

    International Nuclear Information System (INIS)

    Bueppelmann, K.; Kim, J.I.

    1988-06-01

    The chemical behaviour of Plutonium has been investigated in concentrated NaCl solutions in the neutral pH range. The α-radiation induced radiolysis reactions oxidize the Cl - -ion to Cl 2 , HClO, ClO - and other species, which produce a strongly oxidizing medium. Under these conditions the Pu ions of lower oxidation states are readily oxidized to Pu(VI), which then undergo depending on the pH of the solution, various chemical reactions to produce PuO 2 Cl n , PuO 2 (ClO) m or PuO 2 (OH) x species. In addition to primary radiolysis reactions taking place in NaCl solutions, the reactions leading to the PuO 2 (Cl) n and PuO 2 (ClO) m species have been characterized and quantified systematically by spectroscopic and thermodynamic evaluation. The redox and complexation reactions of Pu ions under varying NaCl concentration, specific α-activity and pH are discussed. (orig.) [de

  10. Bioaccumulation, distribution, and dose of 241Am, 244Cm, and 238Pu in developing fish embryos

    International Nuclear Information System (INIS)

    Till, J.E.; Frank, M.L.

    1977-01-01

    The dose from several actinide elements to a sensitive stage in the development of one type of aquatic biota, the fish egg, was assessed. An investigation was made of the uptake and distribution of 241 Am, 244 Cm and 238 Pu by developing embryos of fish. Eggs from ripe carp, Cyprinos carpio, that had been spawned in the laboratory were placed in dishes containing 241 Am(III)- 244 Cm(III)-, or 238 Pu(IV)-citrate in solution at an activity concentration of approximately 10 -3 μCi/ml. Samples of eggs were taken at seven intervals during the 72-hour period of embryogenesis. Egg contents were separated from the membrane prior to analysis to quantify the activity that penetrated the chorion. Autoradiographs of 16-μm thick egg sections confirmed that alpha radioactivity was present in the egg contents and permitted the distribution of activity to be determined. Concentration factors were calculated based on activity ratios for the egg contents (excluding the chorion) over the development period. Maximum concentration factors occurred at hatching and were found to be 25, 40 and 3 for 241 Am, 244 Cm and 238 Pu, respectively. Collectively, these data were used to estimate the dose from americium, curium and plutonium in natural ecosystems to developing fish eggs which have similar embryological characteristics as carp

  11. Trace determination of Pu by LIF in an inductively coupled plasma

    International Nuclear Information System (INIS)

    Mauchien, P.; Briand, A.; Moulin, C.

    1989-01-01

    Inductively Coupled Plasma/Emission Spectrometry (ICP/ES) technique is largely used in the nuclear industry as an elementary analytical technique. Nevertheless, when the sample to analyse presents elements with a lot of emission spectral lines, spectral interferences lead to limited sensitivity. This is the case for Pu determination in presence of large U concentration. In pure aqueous solution, the limit of detection (LOD) for Pu is 10 μg/1. In presence of U, the LOD is determined by a ratio U/Pu = 1000. Pulsed Laser Induced Fluorescence (LIF) spectrometry is known to be a very selective technique when associated with an Inductively Coupled Plasma source. The absolute sensitivity is better by 2 or 3 orders of magnitude; its principle is based on selective excitation of the ionic species in the plasma followed by fluorescence radiation detection of these species; this radiation being practically free from spectral interferences, it is possible to improve the relative LOD. In this presentation, experimental results performed at Cogema/Marcoule laboratory are presented. After the experimental set-up description, first results of LIF are shown: - very good selectivity is effectively obtained, - a series of analytical results obtained with excitation scanning from the visible to the U.V. show that sensitivity of LIF technique is strictly related to the spectroscopic scheme

  12. Chlorine determination in (U, Pu)C fuel by total reflection X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Misra, Nand Lal; Dhara, Sangita; Mudher, Khush Dev Singh; Aggarwal, Suresh K.; Thakur, Uday Kumar; Shah, Dipti; Sawant, R.M.; Ramakumar, K.L.

    2007-01-01

    A Total Reflection X-ray Fluorescence (TXRF) method for the determination of chlorine in (U,Pu)C has been developed. The method involves calibration of the instrument with standard solutions and validation of TXRF determination of chlorine using synthetic standard solutions. Cl K α line excited with W L α source was used for TXRF determinations of chlorine. Chlorine present in trace amounts in (U,Pu)C samples was first separated by pyro hydrolysis. The evolved chlorine, in form of HCl, was collected in 5 mM NaOH solution. This solution was analyzed for chlorine by Total Reflection X-ray Fluorescence Spectrometry using cobalt as an internal standard. The TXRF detection limit of chlorine was found to be 3.6 pg with sample size of 30 μL. In order to assess the applicability of TXRF method for chlorine determinations in other nuclear materials, one U 3 O 8 trace element standard was also analyzed for chlorine in similar way. The precision of the method was found to be 25% (1 σ) at ng level in most of the cases. (author)

  13. Risk estimates for lung tumours from inhaled 239PuO2, 238PuO2, and 239Pu(NO3)4 in beagle dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.; Park, J.F.; Gilbert, E.S.; Weller, R.E.

    1989-01-01

    Lung cancer risks are being studied in beagle dogs given single exposures to aerosols of 239 PuO 2 , 238 PuO 2 , or 239 Pu(NO 3 ) 4 . A major objective of these studies is to examine the risk of lung cancer relative to the specific activity of the radionuclide, rate of dose accumulation due to differences in solubilities of the radionuclides, and the presence of competing risk from extrapulmonary lesions. Dose-response relationships were studied for the three groups of dogs, with analyses specifically designed to evaluate differences in response. Based on estimated cumulative dose to the lung, risks were found to differ significantly among the radionuclides; they were highest for 239 Pu(NO 3 ) 4 and lowest for 238 PuO 2 . A model in which the risk was assumed to be a pure quadratic function of dose fitted the data much better than a pure linear model. Currently, all three groups of dogs can be compared only to 10 years after exposure. However, it is apparent that the average cumulative dose to the lung may not be an adequate predictor of lung cancer risk for different isotopic and physicochemical forms of plutonium. (author)

  14. Bronchopulmonary lavage and DTPA treatment for the removal of inhaled 239Pu of varied solubility in beagle dogs. II

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Miglio, J.J.; Slauson, D.O.; McClellan, R.O.

    1974-01-01

    The efficacy of bronchopulmonary lavage and chelation therapy was determined for removing 239 Pu from Beagle dogs after inhalation of 239 Pu aerosols of differing in vivo solubility. The four aerosols used were nebulized from a solution of 239 PuCl 4 and heat treated at temperatures of 325, 600, 900, and 1150 0 C, respectively. Six dogs were exposed to each of the four aerosols and three dogs in each group were treated subsequently by lavage and intravenous diethylenetriaminepentaacetic acid (DTPA); three dogs served as untreated controls. Tissue accumulation of 239 Pu in the untreated control dogs at sacrifice 56 days post-exposure, expressed as a percentage of the initial lung burden (ILB), was 6 percent in liver and 9 percent in skeleton for the 325 0 C aerosol group, 1 percent in liver and 2 percent in the skeleton for the 600 0 C group, and less than 0.6 percent in these tissues for the 900 0 and 1150 0 C aerosol groups. Tissue accumulation was 1.0 percent or less of the ILB for all organs in the treated groups of dogs. The urinary excretion of 239 Pu was increased in the treated dogs compared to the control dogs that inhaled the 325 0 C and 600 0 C aerosols and was low in all dogs exposed to the 900 0 and 1150 0 C treated aerosol particles. Ten bronchopulmonary lavage procedures removed a mean of 44 percent of the ILB of 239 Pu from the lungs. The aerosol temperature and resulting differences in solubility of the particles did not influence the efficacy of the lavage procedure. An in vitro solubility test predicted the relative in vivo solubility of the four aerosols. These results are discussed in relation to the choice of therapy and its timing. (U.S.)

  15. Top-MOX fuel solution: strategies, challenges, opportunities

    International Nuclear Information System (INIS)

    Breitenstein, P.; Vo Van, V.

    2014-01-01

    TOP-MOX is a nuclear fuel solution and product developed by AREVA and successfully implemented in Europe. It allows utilities burning plutonium (instead of enriched uranium) even when this plutonium is not stemming from own reprocessed used fuel - that is third party plutonium. The important challenges for utilities along with TOP-MOX implementation are legal/patrimonial Pu-ownership issues and general economical aspects. Available sponsorship of such plutonium permits UO2 competitive market prices. For new MOX customers licensing and technical aspects come along. Further AREVA proposes a flexible solution which is called 'TOP-MOX pre-cycling'. This involves making available third party plutonium for fuel fabrication and reactor use pending the utilities' final strategic fuel cycle decision. The paper gives insight into and analyses the impacts of allowing customers the implementation of a TOP-MOX program with focus on Pu-ownership, economics, technical and legal aspects as well as the impact on used MOX management and final waste management. (authors)

  16. A COMPARISON OF (PuU)C AND (PuU)O$sub 2$ FUELED FAST BREEDER REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, A. Halim; Rosen, Stanley

    1963-11-15

    BS>A conceptual evaluation is presented of a (PuU)C 500Mw(e) reactor which uses a moderate power generation of 40 kw/ft and a maximum fuel temperature of 2900 deg F, well below the 4500 deg F melting point of Pu/sub 0.2/U/sub 0.8/C. The principal design characteristics and fuel cycle costs are tabulated together with those of a (PuU)O/sub 2/ design of equal power. The comparison shows that the carbide core has significant economic and safety advantages over the oxide core. (D.L.C.)

  17. Plutonium determination in solution with excess hydrofluoric acid

    International Nuclear Information System (INIS)

    Krtil, J.; Kuvik, V.; Spevackova, V.

    1975-01-01

    The determination is described of plutonium in solutions in the presence of fluoride ions resulting from the hydrolysis of PuF 6 . The method is based on reduction of Pu(VI) by excess of Fe(II) and on re-titration of Fe(II) with ceric salt. The effect of fluoride ions on plutonium determination was studied. It was found that a 3 mole excess of HF with respect to Pu decreased the results of Pu determination. The interference of fluoride ions was eliminated by a two-fold evaporation of the solution to be titrated with HNO 3 to dryness or by complex formation with boric arid. The amount of 20.50 mg Pu in the presence of a 10 mole excess of fluoride ions (17 mg HF) was determined with an error of +- 0.09 mg ). (author)

  18. Decontamination of soils and materials containing medium-fired PuO{sub 2} using inhibited fluorides with polymer filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Temer, D.J.; Villarreal, R.; Smith, B.F. [Los Alamos National Lab., NM (United States)

    1997-10-01

    The decontamination of soils and/or materials from medium-fired plutonium oxide (PuO{sub 2}) with an effective and efficient decontamination agent that will not significantly dissolve the matrix requires a new and innovative technology. After testing several decontamination agents and solutions for dissolution of medium-fired PuO{sub 2}, the most successful decontamination solutions were fluoride compounds, which were effective in breaking the Pu-oxide bond but would not extensively dissolve soil constituents and other materials. The fluoride compounds, tetra fluoboric acid (HBF{sub 4}) and hydrofluorosilicic acid (H{sub 2}F{sub 6}Si), were effective in dissolving medium-fired PuO{sub 2}, and did not seem to have the potential to dissolve the matrix. In both compounds, the fluoride atom is attached to a boron or silicon atom that inhibits the reactivity of the fluoride towards other compounds or materials containing atoms less attracted to the fluoride atom in an acid solution. Because of this inhibition of the reactivity of the fluoride ion, these compounds are termed inhibited fluoride compounds or agents. Both inhibited fluorides studied effectively dissolved medium-fired PuO{sub 2} but exhibited a tendency to not attack stainless steel or soil. The basis for selecting inhibited fluorides was confirmed during leaching tests of medium-fired PuO{sub 2} spiked into soil taken from the Idaho National Engineering Laboratory (INEL). When dissolved in dilute HNO{sub 3}, HCl, or HBr, both inhibited fluoride compounds were effective at solubilizing the medium-fired PuO{sub 2} from spiked INEL soil.

  19. Biosorption of 239Pu by immobilized sargassum fusiforme

    International Nuclear Information System (INIS)

    Liang Zhirong; Chen Qi; Wu Yusheng

    2009-01-01

    Sargassum fusiforme was immobilized with calcium alginates and its biosorption property to 239 Pu was studied by batch and column methods. Biosorption equilibrium time of immobilized Sargassum fusiforme biosorbent to 239 Pu is 120 min and biosorption efficiency is over 99.2% when the initial concentration of 239 Pu is 21.5 kBq/L and pH is 2.5-5.0. After five times repetition biosorption-desorption cycles biosorption efficiency is still over 98.0% when the velocity of flow is 2 ml/min in column experiment. Immobilized Sargassum fusiforme biosorbent is better to 239 Pu due to its better chemical stability, mechanical strength, lower cost, high biosorption efficiency and repeated biosorption-desorption cycles. (authors)

  20. Relative 238Pu content of bone and bone marrow

    International Nuclear Information System (INIS)

    McClanahan, B.J.

    1979-01-01

    Selected bones from a dog that inhaled 238 PuO 2 were subjected to ultrasonic cell disruption to separate the marrow elements from bone, in order to determine the plutonium content of the two components of the skeleton

  1. Irradiation of blood by 238Pu alpha particles

    International Nuclear Information System (INIS)

    Hungate, F.P.; Riemath, W.F.; Culver, G.G.; Gillis, M.F.; Ragan, H.A.

    1976-01-01

    A developmental 238 Pu blood irradiator produced no evidence of lymphopenia in a dog. Irradiation continued for a year at an estimated rate of about 100 rads/day, but this dosimetry is highly uncertain

  2. Determination of Pu and U by ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Y.; Yoshida, S. [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-06-01

    In order to understand the distribution and behaviour of long-lived radionuclides in the terrestrial environment, we have developed analytical methods for {sup 238}U, {sup 232}Th and {sup 239},{sup 240}Pu and determined them in several environmental samples. ICP-MS was applied to the analyses. Concentrations of {sup 238}U and {sup 232}Th were determined in variety of soils, plants and environmental waters. The mean concentration of U and Th in 77 soils, collected several parts of Japan, were 2.3 and 7.0 ppm (dry wt). Red and yellow soils, which are mainly found in western Japan, have high concentrations of Th, suggesting the contribution from granitic rocks. Higher concentration of U in agricultural soils than forest soils suggested the possible accumulation of this element from phosphate fertilizer. The soil-to-plant transfer factors (concentration ratios between plants and soils) of U and Th were estimated from the analytical results of these nuclides in soils and in several crops. The factors for U were about 0.0005 in leaf vegetables, 0.0002 in root vegetables, 0.0001 in potatoes and 0.00001 in rice (polished). For Th, the factors were about 0.0005 in leaf vegetables, 0.0008 in root vegetables, 0.0005 in potatoes and 0.00003 in rice (polished). For the analysis of plutonium, chromatographic resin, Dowex 1x8, was examined for their applicability in the separation of Pu from the matrix elements. Sufficient decontamination factors (10{sup 4}-10{sup 5}) for many matrix elements including U, which interferes in the detection of mass 239, were obtained in both resins. Analytical results of {sup 239+240}Pu in standard reference materials (IAEA-135, -SOIL-6, -368 and -134) indicated that the accuracy of this method was satisfactory. Data on the {sup 240}Pu/{sup 239}Pu atom ratios in these reference materials, which are rare in the literature, were also obtained. Soil samples from the Marshall Islands showed a large variation of the {sup 240}Pu/{sup 239}Pu atom ratios

  3. CONCENTRATION OF Pu USING AN IODATE PRECIPITATE

    Science.gov (United States)

    Fries, B.A.

    1960-02-23

    A method is given for separating plutonium from lanthanum in a lanthanum fluoride carrier precipitation process for the recovery of plutonium values from an aqueous solution. The carrier precipitation process includes the steps of forming a lanthanum fluoride precipi- . tate, thereby carrying plutonium out of solution, metathesizing the fluoride precipitate to a hydroxide precipitate, and then dissolving the hydroxide precipitate in nitric acid. In accordance with the invention, the nitric acid solution, which contains plutonium and lanthanum, is made 0.05 to 0.15 molar in potassium iodate. thereby precipitating plutonium as plutonous iodate and the plutonous iodate is separated from the lanthanum- containing supernatant solution.

  4. Decomposition of metal nitrate solutions

    International Nuclear Information System (INIS)

    Haas, P.A.; Stines, W.B.

    1982-01-01

    Oxides in powder form are obtained from aqueous solutions of one or more heavy metal nitrates (e.g. U, Pu, Th, Ce) by thermal decomposition at 300 to 800 deg C in the presence of about 50 to 500% molar concentration of ammonium nitrate to total metal. (author)

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

    Science.gov (United States)

    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. PuLSE: Quality control and quantification of peptide sequences explored by phage display libraries.

    Science.gov (United States)

    Shave, Steven; Mann, Stefan; Koszela, Joanna; Kerr, Alastair; Auer, Manfred

    2018-01-01

    The design of highly diverse phage display libraries is based on assumption that DNA bases are incorporated at similar rates within the randomized sequence. As library complexity increases and expected copy numbers of unique sequences decrease, the exploration of library space becomes sparser and the presence of truly random sequences becomes critical. We present the program PuLSE (Phage Library Sequence Evaluation) as a tool for assessing randomness and therefore diversity of phage display libraries. PuLSE runs on a collection of sequence reads in the fastq file format and generates tables profiling the library in terms of unique DNA sequence counts and positions, translated peptide sequences, and normalized 'expected' occurrences from base to residue codon frequencies. The output allows at-a-glance quantitative quality control of a phage library in terms of sequence coverage both at the DNA base and translated protein residue level, which has been missing from toolsets and literature. The open source program PuLSE is available in two formats, a C++ source code package for compilation and integration into existing bioinformatics pipelines and precompiled binaries for ease of use.

  7. Transfer of 239Pu to mouse fetoplacental tissues

    International Nuclear Information System (INIS)

    Kubota, Yoshihisa; Sato, Hiroshi; Koshimoto, Chihiro; Takahashi, Sentaro

    1993-01-01

    Cross-placental transfer of 239 Pu from the mother to fetus was studied in C3H mice. The activity of 239 Pu in the conceptus was measured 24 hrs after the intravenous injection of 239 Pu citrate on days 10.5 to 16.5 of gestation. More 239 Pu was transferred to the conceptus when the plutonium was administered in the later stages of gestation; 0.12% of the injected dose per conceptus on day 10.5 and 1.3% on day 16.5. In all the gestational stages examined, the yolk sac and decidua contained more than 89% of the total activity distributed in the conceptus. The concentration of 239 Pu in the yolk sac was about two orders of magnitude greater than that in the fetus. The 239 Pu concentration in the maternal liver decreased with the gestational stage. In the early gestational stages the concentration in the maternal liver was greater than that in the yolk sac; but, this relationship was reversed in the later stages. (author)

  8. Unsafe Coulomb excitation of 240-244Pu

    International Nuclear Information System (INIS)

    Ahmad, I.; Amro, H.; Carpenter, M. P.; Chowdhury, P.; Cizewski, J.; Cline, D.; Greene, J. P.; Hackman, G.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Macchiavelli, A. O.; Nisius, D. T.; Reiter, P.; Seabury, E. H.; Seweryniak, D.; Siem, S.; Uusitalo, J.; Wiedenhoever, I.; Wu, C. Y.

    1999-01-01

    The high spin states of 240 Pu and 244 Pu have been investigated with GAMMASPHERE at ATLAS, using Coulomb excitation with a 208 Pb beam at energies above the Coulomb barrier. Data on a transfer channel leading to 242 Pu were obtained as well. In the case of 244 Pu, the yrast band was extended to 34h b ar revealing the completed πi 13/2 alignment, a ''first'' for actinide nuclei. The yrast sequence of 242 Pu was also extended to higher spin and a similar backbend was delineated. In contrast, while the ground state band of 240 Pu was measured up to the highest rotational frequencies ever reported in the actinide region (approximately300 keV), no sign of particle alignment was observed. In this case, several observable such as the large B(E1)/B(E2) branching ratios in the negative parity band, and the vanishing energy staggering between the negative and positive parity bands suggest that the strength of octupole correlations increases with rotational frequency. These stronger correlations may well be responsible for delaying or suppressing the πi 13/2 particle alignment

  9. Contributions of nonextracting Pu reductants (ferrous sulphamate and hydroxylamine nitrate) and holding reductant (hydrazine nitrate) to the aqueous density in U-Pu partitioning system

    International Nuclear Information System (INIS)

    Shekhar Kumar; Rajnish Kumar; Koganti, S.B.

    2005-08-01

    As nonextracting Pu reductants and holding reductants contribute to the density of aqueous phase sub-system considerably, to account their contributions in aqueous phase in solvent extraction simulation code is essential. In this regard, in-house generated precise density data on aqueous ferrous sulphamate solutions as well as aqueous density data, reported in the literature, for HAN, hydrazine nitrate and HAN-HNO 3 systems were analyzed and density equation earlier proposed by authors was extended to it. It was observed that the equation earlier proposed by the authors were simple and were easy to extend for multicomponent system. The contributions of ferrous sulphamate, HAN and hydrazine nitrate to the aqueous density were quantified. It was also observed that the classical value of contribution for nonextractible solute to the aqueous density was quite different from the results reported in this work. (author)

  10. APA: U free Pu pin in a heterogeneous assembly to improve Pu loading in a PWR - neutronic, thermo-hydraulic and manufacturing studies

    International Nuclear Information System (INIS)

    Porta, J.; Puill, A.; Bauer, M.; Matheron, P.

    1999-01-01

    After having presented the specific context of France with respect to the fuel cycle and reprocessing, the problem of plutonium fuel utilization is posed. If one of the solutions, a pressurized water reactor (PWR) with an increased moderation ratio seems possible, it entails making excessive changes to the reactor, the control systems, and the general architecture of the steam supply system. Another solution consists in modifying the fuel itself so as to eliminate conversion on 238 U by using plutonium (Pu) in a neutronically inert matrix. However, the disadvantage of this type of fuel is that it has very low Doppler and draining coefficients and a very small delayed neutron fraction. To enable using these fuels, a heterogeneous assembly has to be defined, in which standard UO 2 rods provide the physical properties required to ensure acceptable safety coefficients. (author)

  11. Effect of long-term storage of LWR spent fuel on Pu-thermal fuel cycle

    International Nuclear Information System (INIS)

    Kurosawa, Masayoshi; Naito, Yoshitaka; Suyama, Kenya; Itahara, Kuniyuki; Suzuki, Katsuo; Hamada, Koji

    1998-01-01

    According to the Long-term Program for Research, Development and Utilization of Nuclear Energy (June, 1994) in Japan, the Rokkasho Reprocessing Plant will be operated shortly after the year 2000, and the planning of the construction of the second commercial plant will be decided around 2010. Also, it is described that spent fuel storage has a positive meaning as an energy resource for the future utilization of Pu. Considering the balance between the increase of spent fuels and the domestic reprocessing capacity in Japan, it can be expected that the long-term storage of UO 2 spent fuels will be required. Then, we studied the effect of long-term storage of spent fuels on Pu-thermal fuel cycle. The burnup calculation were performed on the typical Japanese PWR fuel, and the burnup and criticality calculations were carried out on the Pu-thermal cores with MOX fuel. Based on the results, we evaluate the influence of extending the spent fuel storage term on the criticality safety, shielding design of the reprocessing plant and the core life time of the MOX core, etc. As the result of this work on long-term storage of LWR spent fuels, it becomes clear that there are few demerits regarding the lifetime of a MOX reactor core, and that there are many merits regarding the safety aspects of the fuel cycle facilities. Furthermore, long-term storage is meaningful as energy storage for effective utilization of Pu to be improved by technological innovation in future, and it will allow for sufficient time for the important policymaking of nuclear fuel cycle establishment in Japan. (author)

  12. Performance of cladding on MOX fuel with low 240Pu/239Pu ratio

    International Nuclear Information System (INIS)

    McCoy, K.; Blanpain, P.; Morris, R.

    2015-01-01

    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 240 Pu/ 239 Pu 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. (authors)

  13. Assessment of 238Pu and 239+240Pu, in marine sediments of the oceans Atlantic and Pacific of Guatemala

    International Nuclear Information System (INIS)

    Mendez Ochaita, L.

    2000-01-01

    In this investigation samples of marine sediments were taken from 14 places representatives of the oceans coast of Guatemala. For the assesment of 238 Pu and 239+240 Pu in sediments a radiochemical method was used to mineralize sediments and by ionic interchange it was separated from other elements, after that an electrodeposition of plutonium was made in metallic discs. The radioactivity of plutonium was measured by alpha spectrometry system and the alpha spectrums were obtained. The levels of plutonium are not higher than other countries that shown contamination. The contamination of isotope of 239+240 Pu is higher than 238 Pu and the contamination by two isotopes of plutonium is higher in the Atlantic than the Pacific ocean

  14. Aspects of 238Pu production in the experimental fast reactor JOYO

    International Nuclear Information System (INIS)

    Osaka, Masahiko; Koyama, Shin-ichi; Tanaka, Kenya; Itoh, Masahiko; Saito, Masaki

    2005-01-01

    Experimental determination of 238 Pu in 237 Np samples irradiated in the experimental fast reactor JOYO was done as part of the demonstration of 238 Pu production from 237 Np in fast reactors within the framework of the protected Pu production project, which aims at reinforcement of proliferation resistance of Pu by increasing the 238 Pu isotopic ratio. 238 Pu production amount in the irradiated 237 Np samples was determined by a radioanalytical technique. Aspects of 238 Pu production were examined on the basis of the present radioanalysis. The 238 Pu production amount depends on the neutron spectrum which can range from that of a typical fast reactor to a nearly epi-thermal spectrum. It is concluded that the fast reactor has not only high potential for use in protected Pu production, but also as an incinerator for excess Pu

  15. Physical and economical aspects of Pu multiple recycling on the basis of REMIX reprocessing technology in thermal reactors

    International Nuclear Information System (INIS)

    Teplov, P.S.; Alekseev, P.N.; Bobrov, E.A.; Chibinyaev, A.V.

    2016-01-01

    The basic strategy of Russian nuclear energy is propagation of a closed fuel cycle on the basis of fast breeder and thermal reactors, as well as the solution of the spent nuclear fuel accumulation and resource problems. The 3 variants of multiple Pu and U recycling in Russian pressurized water reactor concept reactors on the basis of Regenerated Mixture of U, Pu oxides (REMIX) reprocessing technology are considered in this work. The REMIX fuel is fabricated from an un-separated mixture of uranium and plutonium obtained during spent fuel reprocessing with further makeup by enriched natural U or reactor grade Pu. This makes it possible to recycle several times the total amount of Pu obtained from the spent fuel. The main difference in Pu recycling is the concept of 100% or partial fuel loading of the core. The third variant is heterogeneous composition of enriched uranium and uranium-plutonium mixed oxide fuel pins in one fuel assembly. It should be noted that all fuel assemblies with Pu require the involvement of expensive technologies during manufacturing. These 3 variants of the full core loadings can be balanced on zero Pu accumulation in the cycle. The various physical and economical aspects of Pu and U multiple recycling in selected variants are presented in the given work. The better results in natural uranium savings can be achieved for the standard REMIX(UOX) approach. The usage of regenerated materials in thermal power reactors gives not more than 30% saving of natural uranium consumption. It is important to note that the use of REMIX technology in the closed fuel cycle is more expensive than the open fuel cycle with direct spent fuel disposal. It is also important to see that uranium multiple recycling in the REMIX fuel form or using the re-enrichment process leads to the degradation of the uranium isotope composition. The "2"3"6U and "2"3"2U concentrations in the fuel are increasing and the regenerated uranium treatment becomes more complicated

  16. Estimation of uncertainties in resonance parameters of {sup 56}Fe, {sup 239}Pu, {sup 240}Pu and {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tsuneo; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    Uncertainties have been estimated for the resonance parameters of {sup 56}Fe, {sup 239}Pu, {sup 240}Pu and {sup 238}U contained in JENDL-3.2. Errors of the parameters were determined from the measurements which the evaluation was based on. The estimated errors have been compiled in the MF32 of the ENDF format. The numerical results are given in tables. (author)

  17. Cation interdiffusion in the UO2 - (U, Pu)O2 and UO2 - PuO2 systems

    International Nuclear Information System (INIS)

    Leme, D.G.

    1985-01-01

    The interdiffusion of U and Pu ions in UO sub(2 +- x) - (U sub(0,83) Pu sub(0,17))O sub(2 + - x) and UO sub(2 + - x) -PuO sub(2 - x) sintered pellets and UO sub(2 +- x) -(U sub(0,82) Pu sub(0,18))O sub(2 + - x) single crystals has been studied as a function of the oxygen potential ΔG sup(-) (O 2 ) or the stoichiometric ratio O/M. The diffusion profiles of UO 2 /(U,Pu)O 2 and UO 2 /PuO 2 couples of different O/M ratios have been measured using high resolution α-spectrometer and microprobe. Thermal annealing of the specimens was performed in controlled atmospheres using either CO-CO 2 gas mixtures for constant O/M ratios or purified argon. The interdiffusion profiles have been analysed by means of the Boltzmann-Matano and Hall methods. The interdiffusion coefficient D sus(approx.) increases with increasing Pu content in sintered pellets (up to 17 wt. %PuO 2 ) showing a strong dependence of D sup(approx.) on the O/M ratio. The micropobe results show that the interdiffusion along grain boundaries is the main diffusion mechanism in the pellets. Experiments have also been carried out in single cristals to measure just the bulk-interdiffusion and avoiding effects due to grain boundaries. A marked dependence of D sup(approx.) on O/M ratio or on oxygen potential ΔG sup(-) (O 2 ), similar to the dependence already reported for self diffusion by means of radioactive tracers, has also been observed. (Author) [pt

  18. Chemical properties of the predicted 32-electron systems PuSn{sub 12} and PuPb{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Dognon, J.P. [CEA Saclay, UMR 3299 CEA/CNRS SIS2M, laboratoire de chimie de coordination des elements f, 91 - Gif-sur-Yvette (France); Clavaguera, C. [Laboratoire des mecanismes reactionnels, departement de chimie, Ecole polytechnique, CNRS, 91 - Palaiseau (France); Pyykko, P. [Department of Chemistry, University of Helsinki (Finland)

    2010-06-15

    The electronic structures, as well as spectroscopic and thermodynamic properties of the title PuM{sub 12} clusters, are considered at the density functional theory level. In both cases, a Pu{sup 2+} ion is encapsulated in an icosahedral, stanna- or plumbaspherene M{sub 12}{sup 2-} cage. As suggested before for M=Pb, both systems are reported to follow a 32-electron principle for the central atom. (authors)

  19. Vertical profiles of 239(240)Pu, 238Pu and 241Am in some peculiar Italian mosses

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Guerra, F.; Meli, M.A.; Roselli, C.; Jia, G.; Degetto, S.

    2000-01-01

    During the last two years the Urbino University and the Padua ICTIMA CNR were working on a special radioecological program having the aim to study the Pu and Am retention behaviour in different species of mosses growing in two Italian regions (Urbino, Central Italy, 450 m a.s.l. and Alps region, Northern Italy, 1500 m a.s.l.). 239,240 Pu, 238 Pu and 241 Am were separated and determined by extraction chromatography, electroplating and alpha spectrometry; 242 Pu and 243 Am were used as the yield tracers. The paper summarizes the results dealing with the vertical profiles of the radionuclides in three different species of mosses. Several 1-2 cm high sections were obtained and dated by 210 Pb determination. Typical concentration peaks for Pu and Am were found for very old moss species ('Sphagnum Compactum' and 'Sphagnum Nemoreum') at a depth corresponding to the early 1960's which is the period characterized by the maximum nuclear weapon tests. In more recent moss species ('Neckeria Crispa') no peak was observed and the regression curves showed that Am is more mobile than Pu. (author)

  20. Reaction of plutonium with water kinetic and equilibrium behavior of binary and ternary phases in the Pu + O + H system

    International Nuclear Information System (INIS)

    Haschke, J.M.; Hodges, A.E. III; Bixby, G.E.; Lucas, R.L.

    1983-01-01

    The kinetic and equilibrium behavior of the Pu + O + H system has been studied by measuring the production of hydrogen gas formed by a sequence of hydrolysis reactions. The kinetic dependence of the Pu + H 2 O reaction on salt concentration and temperature has been defined. The metal is quantitatively converted to a fine black powder which has been identified as plutonium monoxide monohydride, PuOH. Other hydrolysis products formed in aqueous media include a second oxide hydride, Pu 7 O 9 H 3 , and the oxides Pu 2 O 3 , Pu 7 O 12 , Pu 9 O 16 , Pu 10 O 18 , Pu 12 O 22 , and PuO 2 . Thermal decomposition products of PuOH include Pu 2 O 2 H and PuO. A tentative phase diagram for Pu + O + H is presented and structural relationships of the oxide hydrides and oxides are discussed. 10 figures, 5 tables

  1. Geochemical association of Pu and Am in selected host-phases of contaminated soils from the UK and their susceptibility to chemical and microbiological leaching

    International Nuclear Information System (INIS)

    Kimber, Richard L.; Corkhill, Claire L.; Amos, Sean; Livens, Francis R.; Lloyd, Jonathan R.

    2015-01-01

    Understanding the biogeochemical behaviour and potential mobility of actinides in soils and groundwater is vital for developing remediation and management strategies for radionuclide-contaminated land. Pu is known to have a high Kd in soils and sediments, however remobilization of low concentrations of Pu remains a concern. Here, some of the physicochemical properties of Pu and the co-contaminant, Am, are investigated in contaminated soils from Aldermaston, Berkshire, UK, and the Esk Estuary, Cumbria, UK, to determine their potential mobility. Sequential extraction techniques were used to examine the host-phases of the actinides in these soils and their susceptibility to microbiological leaching was investigated using acidophilic sulphur-oxidising bacteria. Sequential extractions found the majority of 239,240 Pu associated with the highly refractory residual phase in both the Aldermaston (63.8–85.5 %) and Esk Estuary (91.9–94.5%) soils. The 241 Am was distributed across multiple phases including the reducible oxide (26.1–40.0%), organic (45.6–63.6%) and residual fractions (1.9–11.1%). Plutonium proved largely resistant to leaching from microbially-produced sulphuric acid, with a maximum 0.18% leached into solution, although up to 12.5% of the 241 Am was leached under the same conditions. If Pu was present as distinct oxide particles in the soil, then 241 Am, a decay product of Pu, would be expected to be physically retained in the particle. The differences in geochemical association and bioleachability of the two actinides suggest that this is not the case and hence, that significant Pu is not present as distinct particles. These data suggest the majority of Pu in the contaminated soils studied is highly recalcitrant to geochemical changes and is likely to remain immobile over significant time periods, even when challenged with aggressive “bioleaching” bacteria. - Highlights: • Pu in the contaminated soils is associated with the recalcitrant

  2. Fission track analysis of Pu in small specimens of biological material: Technical progress report, August 1, 1987--July 31, 1988

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1988-01-01

    The objective of this research is to develop a highly specific and ultrasensitive method capable of detecting 100 aCi/liter of 239 Pu in human urine. The method using neutron induced fission track analysis is to be made free of interference from uranium, the only naturally occurring element with an isotope which fissions with thermal neutrons. A simplified flow diagram for the method is shown in Figure 1. Briefly 239 Pu is coprecipitated quantitatively from urine with rhodozonic acid. The precipitate containing the 239 Pu is dissolved in HCl and is sequentially passed through two ion exchange columns and reduced in volume. The element is then deposited in a circular area on a thick polycarbonate detector and a thinner detector is placed over the circular deposit. The plastic detectors are then irradiated to a high thermal neutron fluence in a research reactor. The detectors are etched in a caustic solution for controlled times and temperatures in order to develop the fission tracks. Images of tracks are formed both on the thin and thick plastic detectors. Total tracks in the thinner detector are measured with a locally developed spark counter and in the thick plastic are measured by counting with a microscope. The results will be made quantitative by constructing a calibration curve for 239 Pu. 3 refs., 9 figs., 3 tabs

  3. The Transport of Close-In Fallout Plutonium in the Northwest Pacific Ocean: Tracing the Water Mass Movement Using {sup 240}Pu/{sup 239}Pu Atom Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Han [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Hong, Gi-Hoon; Suk, Moon-Sik [Korea Ocean Research and Development Institute, Seoul (Korea, Republic of); Gastaud, J. [International Atomic Energy Agency, Marine Environment Laboratory (Monaco); La Rosa, J. [National Institute of Standards and Technology, Ionizing Radiation Division, Gaithersburg, Maryland (United States); Kim, Chul-Soo [Environmental Laboratories, International Atomic Energy Agency, Seibersdorf (Austria); Wyse, E. [New Brunswick Laboratory Argonne, IL (United States); Povinec, P. P. [Comenius University, Faculty of Mathematics and Physics, Bratislava (Slovakia)

    2013-07-15

    {sup 240}Pu/{sup 239}Pu atom ratios in seawater and surface sediment collected from the northwest (NW) Pacific Ocean from 1992 to 1997 were determined using ICP-sector field mass spectrometry (ICP-MS). In whole water columns, the atom ratios of {sup 240}Pu/{sup 239}Pu were higher than the global fallout ratio (0.18). It is noted that the atom ratios of {sup 240}Pu/2{sup 39}Pu in the seawater increase with depth. Such elevated {sup 240}Pu/{sup 239}Pu atom ratios indicate that the close-in fallout plutonium isotopes originating from the Pacific Proving Grounds (PPGs) due to the U.S. tests are prevailing in the seawater in the NW Pacific Ocean. However, the {sup 240}Pu/{sup 239}Pu atom ratios in the surface sediment from the NW Pacific Ocean varied with the sampling locations. As a consequence, this study will provide the information that the water mass along with the current plays a key role in driving the distribution of Pu and in transporting Pu from the PPGs to the far eastern marginal sea in the NW Pacific Ocean. (author)

  4. Archiver ce qui aurait pu avoir lieu

    Directory of Open Access Journals (Sweden)

    Stefanie Baumann

    2009-12-01

    Full Text Available L’Atlas Group, un projet de l’artiste libanais Walid Raad, est « dédié à la recherche et la compilation de documents sur l’histoire contemporaine libanaise. L’Atlas Group produit, localise, conserve et étudie des documents visuels, sonores, textuels et autres, qui mettent en lumière l’histoire actuelle du Liban. »Ce projet est ainsi présenté comme une fondation qui génère des archives historiques et qui collecte des traces relevant de la guerre au Liban afin de les mettre à disposition aux chercheurs. Mais, les matériaux sont produits par l’artiste : l’archive est imaginaire, les documents et récits sont inventés, ainsi que le Docteur Fakhouhi, le personnage principal, présenté comme étant « le plus renommé des historiens au Liban ». Le spectateur se trouve alors devant un scénario très étrange dans lequel sont détournées les notions de document (qui peut désormais être aussi bien trouvé que produit et d’histoire (car les situations décrites sont considérées comme « ayant très bien pu avoir eu lieu », l’Atlas Group  les traite comme de véritables événement historiques et qui déplace, mine de rien, tout un dispositif. Au sein de ce projet, la frontière entre fiction et documentaire est complètement estompée : le geste de l’artiste (qui, lui, se présente comme une institution, un « Groupe », interroge ainsi le statut même d’auteur vise à la déplacer pour poser des questions relatives aux représentations possibles de l’histoire, aux personnes aptes à se charger de son écriture et à l’opération historiographique.

  5. USTUR WHOLE BODY CASE 0269: DEMONSTRATING EFFECTIVENESS OF I.V. CA-DTPA FOR PU

    Energy Technology Data Exchange (ETDEWEB)

    James, Anthony C.; Sasser , Lyle B.; Stuit, Dorothy B.; Glover, Samuel E.; Carbaugh, Eugene H.

    2008-01-28

    This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO3)4 solution in the form of an aerosol ‘mist.’ Chelation treatment with i.v. Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2½ years with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of 239+240Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation), and continuing for 37 years. This sampling included all intervals of chelation. In addition, 91 measurements of 239+240Pu-in-feces were recorded over this whole period. The Registrant died about 38 years after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their 238Pu, 239+240Pu and 241Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive dataset has been applied to derive ‘chelation-enhanced’ transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are approximately 40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys, and 50% for the skeleton. Essentially all of the substantial reduction in skeletal burden occurred in trabecular bone. This modeling exercise demonstrated that 3-y-delayed Ca-DTPA therapy was as

  6. Ustur whole body case 0269: demonstrating effectiveness of i.v. CA-DTPA for Pu

    Energy Technology Data Exchange (ETDEWEB)

    James, A.C.; Sasser, L.B.; Stuit, D.B. [US Transuranium and Uranium Registries, College of Pharmacy, Washington State University, 1845 Terminal Drive, Suite 201, Richland, WA 99354 (United States); Glover, S.E. [Department of Mechanical, Industrial and Nuclear Engineering, University of Cincinnati, 598 Rhodes Hall, Cincinnati, OH 45221 (United States); Carbaugh, E.H. [Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99354 (United States)

    2007-07-01

    This whole body donation case (USTUR Registrant) involved a single acute inhalation of an acidic Pu(NO{sub 3}){sub 4} solution in the form of an aerosol 'mist'. Chelation treatment with intravenously (i.v.) Ca-EDTA was initiated on the day of the intake, and continued intermittently over 6 months. After 2.5 y with no further treatment, a course of i.v. Ca-DTPA was administered. A total of 400 measurements of {sup 239+240}Pu excreted in urine were recorded; starting on the first day (both before and during the initial Ca-EDTA chelation) and continuing for 37 y. This sampling included all intervals of chelation. In addition, 91 measurements of {sup 239+240}Pu-in-feces were recorded over this whole period. The Registrant died about 38 y after the intake, at age 79 y, with extensive carcinomatosis secondary to adenocarcinoma of the prostate gland. At autopsy, all major soft tissue organs were harvested for radiochemical analyses of their {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am content. Also, all types of bone (comprising about half the skeleton) were harvested for radiochemical analyses, as well as samples of skin, subcutaneous fat and muscle. This comprehensive data set has been applied to derive 'chelation-enhanced' transfer rates in the ICRP Publication 67 plutonium biokinetic model, representing the behaviour of blood-borne and tissue-incorporated plutonium during intervals of therapy. The resulting model of the separate effects of i.v. Ca-EDTA and Ca-DTPA chelation shows that the therapy administered in this case succeeded in reducing substantially the long-term burden of plutonium in all body organs, except for the lungs. The calculated reductions in organ content at the time of death are {approx}40% for the liver, 60% for other soft tissues (muscle, skin, glands, etc.), 50% for the kidneys and 50% for the skeleton. Essentially, all of the substantial reduction in skeletal burden occurred in trabecular bone. This modelling exercise

  7. Isotope dilution alpha spectrometry for the determination of plutonium concentration in irradiated fuel dissolver solution : IDAS and R-IDAS

    International Nuclear Information System (INIS)

    Ramaniah, M.V.; Jain, H.C.; Aggarwal, S.K.; Chitambar, S.A.; Kavimandan, V.D.; Almaula, A.I.; Shah, P.M.; Parab, A.R.; Sant, V.L.

    1980-01-01

    The report presents a new technique, Isotope Dilution Alpha Spectrometry (IDAS) and Reverse Isotope Dilution Alpha Spectrometry (R-IDAS) for determining the concentration of plutonium in the irradiated fuel dissolver solution. The method exploits sup(238)Pu in IDAS and sup(239)Pu in R-IDAS as a spike and provides an alternative method to Isotope Dilution Mass Spectrometry (IDMS) which requires enriched sup(242)Pu as a spike. Depending upon the burn-up of the fuel, sup(238)Pu or sup(239)Pu is used as a spike to change the sup(238)Pu/(sup(239)Pu+sup(240)Pu)α activity ratio in the sample by a factor of 10. This change is determined by α-spectrometry on electrodeposited sources using a solid state silicon surface barrier detector coupled to a multichannel analyser. The validity of a simple method based on the geometric progression (G.P.) decrease for the far tail of the spectrum to correct for the tail contribution of sup(238)Pu peak (5.50 MeV) to the low energy sup(239)Pu + sup(240)Pu peak (5.17 MeV) is established. Results for the plutonium concentration on different irradiated fuel dissolver solutions with burn-uo ranging from J,000 to 100,000 MWD/TU are presented and compared with those obtained by IDMS. The values obtained by IDAS or R-IDAS and IDMS agree within 0.5%. (auth.)

  8. The geometric structures, vibrational frequencies and redox properties of the actinyl coordination complexes ([AnO2(L)n](m); An = U, Pu, Np; L = H2O, Cl-, CO3(2-), CH3CO2(-), OH-) in aqueous solution, studied by density functional theory methods.

    Science.gov (United States)

    Austin, Jonathan P; Sundararajan, Mahesh; Vincent, Mark A; Hillier, Ian H

    2009-08-14

    The geometric and electronic structures of the aqua, chloro, acetato, hydroxo and carbonato complexes of U, Np and Pu in both their (VI) and (V) oxidation states, and in an aqueous environment, have been studied using density functional theory methods. We have obtained micro-solvated structures derived from molecular dynamics simulations and included the bulk solvent using a continuum model. We find that two different hydrogen bonding patterns involving the axial actinyl oxygen atoms are sometimes possible, and may give rise to different An-O bond lengths and vibrational frequencies. These alternative structures are reflected in the experimental An-O bond lengths of the aqua and carbonato complexes. The variation of the redox potential of the uranyl complexes with the different ligands has been studied using both BP86 and B3LYP functionals. The relative values for the four uranium complexes having anionic ligands are in surprisingly good agreement with experiment, although the absolute values are in error by approximately 1 eV. The absolute error for the aqua species is much less, leading to an incorrect order of the redox potentials of the aqua and chloro species.

  9. Estimation of Ni63, Pu241, Pu242 and Am243 from Co60, Pu239, and Cm244 activities in groundwater samples

    International Nuclear Information System (INIS)

    Holcomb, H.P.

    1993-01-01

    The Part B Permit for F ampersand H Seepage Basins calls for analysis of several constituents of concern in groundwater monitoring wells. Four of these analytes are the radionuclides Ni 63 , Pu 241 , Pu 242 , and Am 243 . These are currently not being analyzed due to their very difficult, tedious analytical schemes coupled with their relatively low activity values. This report demonstrates how the activity value for Ni 63 , a week beta emitter, can be estimated from that of Co 60 , an easily detectable, high-energy gamma emitter. Similarly, estimates of Pu 241 , a beta emitter, and the alpha-emitting Pu 242 can be made from the activity value of the more easily detected Pu 239 . Am 243 can be estimated from the activity of Cm 244 , which is easier to detect because of a shorter half-life (higher specific activity) and the emission of higher energy alpha particles. These correlations are made under very specific parameters in order to ensure the validity of this approach. Therefore, assumptions must be established setting ground rules for establishing these activity relationships. Bases for these assumptions are explained and/or referenced. Their degree of uncertainty limits the accuracy of the data so that the term ''estimate'' is used. Such soundly-based, conservative estimates for these four rads can provide a tool for evaluating any hazards from their presence over the next several years. Hopefully, during this time, sufficient advances will be made in their radiochemical analyses and in counting techniques so that in the future, their activities may be quantitatively determined more easily and also more cost effectively

  10. Finite element analysis of local overheating within plutonium enriched UO2 fuel rods caused by PuO2 islands

    International Nuclear Information System (INIS)

    Sarmiento, G.S.

    1980-01-01

    Within natural UO 2 fuel elements enriched with plutonium, this last material should form PuO 2 solid solutions inside the UO 2 pellets, in a wide range of concentrations. If the solutions are obtained by mechanical mixing of the oxides, PuO 2 islands are formed in the UO 2 matrix. These islands may be the source of several problems in the fuel behaviour, the most important being the overheating of the matrix in the neighbourhood of the particles. It is caused by the large fission cross section of plutonium compared with that of uranium. A detailed study of the thermal effects produced by PuO 2 particles in the UO 2 matrix and the cladding is then important for the specification of their permissible size. A portion of the fuel rods with spherical particles in the most significant places was studied. In order to obtain the dimensionless overheating of the fuel and cladding produced by the presence of those particles, the spatial distribution of temperature was calculated, solving the stationary and linear bidimensional equation of heat conducting using a finite element code. Several geometrical variables and material properties have been taken as dimensionless parameters. A satisfactory convergence of the numerical results to an asymptotic limit with a well-known exact solution, has been obtained. (orig.)

  11. Recovery of plutonium from solvent wash solutions

    International Nuclear Information System (INIS)

    Kyser, E.A.

    1992-01-01

    A number of potential alternatives to the acid hydrolysis recovery of Pu were investigated. The most promising alternative for short-term use appears to be an anion exchange process that would eliminate the long boiling times and the multiple-pass concentration steps needed with the solvent extraction process because it separates the Pu from the dibutyl phosphate (DBP) while at the same time concentrating the Pu. However, restart of the Primary Recovery Column (PRC) to process this solution would require significant administrative effort. The original boiling recovery by acid hydrolysis followed by solvent extraction is probably the most expedient way to process the Pu-DBP-carbonate solution currently stored in tank 13.5 even with its long processing times and dilute product concentration. Anion exchange of a heat stabilized acidified solution is a more efficient process, but requires restart of the PRC. Extended-boiling acid hydrolysis or anion exchange of a heat stabilized acidified solution provide two well developed alternatives for recovery of the Pu from the tank 13.5 carbonate. Further work defining additional recovery processes is not planned at this time

  12. Fractionation of 137Cs and Pu in natural peatland

    International Nuclear Information System (INIS)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-01-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  13. Measurements Conducted on an Unknown Object Labeled Pu-239

    International Nuclear Information System (INIS)

    Hoteling, Nathan

    2013-01-01

    Measurements were carried out on 12 November 2013 to determine whether Pu-239 was present on an object discovered in a plastic bag with label ''Pu-239 6 uCi''. Following initial survey measurements to verify that the object was not leaking or contaminated, spectra were collected with a High Purity Germanium (HPGe) detector with object positioned in two different configurations. Analysis of the spectra did not yield any direct evidence of Pu-239. From the measured spectra, minimum detectable activity (MDA) was determined to be approximately 2 uCi for the gamma ray measurements. Although there was no direct evidence of Pu-239, a peak at 60 keV characteristic of Am-241 decay was observed. Since it is very likely that Am-241 would be present in aged plutonium samples, this was interpreted as indirect evidence for the presence of plutonium on the object. Analysis of this peak led to an estimated Pu-239 activity of 0.02-0.04 uCi, or <1x10 -6 grams.

  14. Vertical distribution of 241Pu in the southern Baltic Sea sediments

    International Nuclear Information System (INIS)

    Strumińska-Parulska, Dagmara I.

    2014-01-01

    Highlights: • The unique study on 241 Pu in sediments from the southern Baltic Sea was presented. • 241 Pu was determined using alpha spectrometry by indirect method. • The biggest amount of 241 Pu existed in the surface layers of all analyzed sediments. • The highest 241 Pu amount comes from the Chernobyl accident. - Abstract: The vertical distribution of plutonium 241 Pu in marine sediments can assist in determining the deposition history and sedimentation process of analyzed regions. In addition, 241 Pu/ 239+240 Pu activity ratio could be used as a sensitive fingerprint for radioactive source identification. The present preliminary studies on vertical distribution of 241 Pu in sediments from four regions of the southern Baltic Sea are presented. The distribution of 241 Pu was not uniform and depended on sediment geomorphology and depth as well as location. The highest concentrations of plutonium were found in the surface layers of all analyzed sediments and originated from the Chernobyl accident

  15. ZZ WPPR-FR-MOX/BNCMK, Benchmark on Pu Burner Fast Reactor

    International Nuclear Information System (INIS)

    Garnier, J.C.; Ikegami, T.

    1993-01-01

    Description of program or function: In order to intercompare the characteristics of the different reactors considered for Pu recycling, in terms of neutron economy, minor actinide production, uranium content versus Pu burning, the NSC Working Party on Physics of Plutonium Recycling (WPPR) is setting up several benchmark studies. They cover in particular the case of the evolution of the Pu quality and Pu fissile content for Pu recycling in PWRs; the void coefficient in PWRs partly fuelled with MOX versus Pu content; the physics characteristics of non-standard fast reactors with breeding ratios around 0.5. The following benchmarks are considered here: - Fast reactors: Pu Burner MOX fuel, Pu Burner metal fuel; - PWRs: MOX recycling (bad quality Pu), Multiple MOX recycling

  16. Pu Denaturing by Transmutation of MA in FBR Multi-cycle

    Energy Technology Data Exchange (ETDEWEB)

    Meiliza, Yoshitalia; Saito, Masaki; Sagara, Hiroshi [Tokyo Institute of Technology, 2-12-1-N1-1 Ookayama, Meguro-ku, Tokyo, 1528550 (Japan)

    2009-06-15

    Pu accumulation and its recycling is important in the term of energy resources, however one of the most sensitive issues is non-proliferation in the future fuel cycle based on fast breeder reactor (FBR). The present paper utilizes Protected Pu Production (P{sup 3}) concept for the production of {sup 238}Pu and {sup 242}Pu by Minor Actinides (MA) transmutation to enhance the proliferation resistance of Pu in the fuel. Increase in the {sup 238}Pu and {sup 242}Pu isotopic fraction creates a high rate of internal heat generation by alpha decay (DH) and/or a high neutron source of spontaneous fission (SFN) in Pu that would be encountered during manufacturing and maintaining of nuclear explosive device. The feasibility of denaturing of Pu by MA transmutation in medium size FBR has been studied from the viewpoint of even-mass number Pu accumulation during multi-cycle of Pu and MA. The proliferation resistance property of Pu is also evaluated based on the specific decay heat and spontaneous fission neutron, compared with the reference criteria. In present paper, the P{sup 3} technology based on multi-recycled Pu and MA is compared with the conventional technology based on multi-recycled Pu only. The detail of mass balance behavior is, however, beyond the scope of the present paper. (authors)

  17. Pu and 137Cs in the Yangtze River estuary sediments: distribution and source identification.

    Science.gov (United States)

    Liu, Zhiyong; Zheng, Jian; Pan, Shaoming; Dong, Wei; Yamada, Masatoshi; Aono, Tatsuo; Guo, Qiuju

    2011-03-01

    Pu isotopes and (137)Cs were analyzed using sector field ICP-MS and γ spectrometry, respectively, in surface sediment and core sediment samples from the Yangtze River estuary. (239+240)Pu activity and (240)Pu/(239)Pu atom ratios (>0.18) shows a generally increasing trend from land to sea and from north to south in the estuary. This spatial distribution pattern indicates that the Pacific Proving Grounds (PPG) source Pu transported by ocean currents was intensively scavenged into the suspended sediment under favorable conditions, and mixed with riverine sediment as the water circulated in the estuary. This process is the main control for the distribution of Pu in the estuary. Moreover, Pu is also an important indicator for monitoring the changes of environmental radioactivity in the estuary as the river basin is currently the site of extensive human activities and the sea level is rising because of global climate changes. For core sediment samples the maximum peak of (239+240)Pu activity was observed at a depth of 172 cm. The sedimentation rate was estimated on the basis of the Pu maximum deposition peak in 1963-1964 to be 4.1 cm/a. The contributions of the PPG close-in fallout Pu (44%) and the riverine Pu (45%) in Yangtze River estuary sediments are equally important for the total Pu deposition in the estuary, which challenges the current hypothesis that the riverine Pu input was the major source of Pu budget in this area.

  18. Characterization of a neutron source of {sup 239}PuBe; Caracterizacion de una fuente de neutrones de {sup 239}PuBe

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez V, R.; Chacon R, A.; Hernandez D, V. M.; Mercado, G. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico)], e-mail: ruben_zac@yahoo.com

    2009-10-15

    The spectrum equivalent dose and environmental equivalent dose f a {sup 239}PuBe source have been determined. The appropriate handling of a neutron source depends on the knowledge of its characteristics, such as its energy distribution, total rate of flowing and dosimetric magnitudes. In many facilities have not spectrometer that allows to determine the spectrum and then area monitors are used that give a dosimetric magnitude starting from measuring the flowing rate and the use of conversion factors, however this procedure has many limitations and it is preferable to measure the spectra and starting from this information the interest dosimetric magnitudes are calculated. In this work a Bonner sphere spectrometer has been used with a {sup 6}LiI(Eu) scintillator obtaining the count rates that produce, to a distance of 100 cm, a {sup 239}PuBe source of 1.85E(11) Bq. The spectrum was reconstructed starting from the count rates using BUNKIUT code and response matrix UTA4. With the spectrum information was calculated the source intensity, total flow, energy average, equivalent dose rate, environmental equivalent dose rate, equivalent dose coefficient and environmental equivalent dose coefficient. By means of two area monitors for neutrons, Eberline ASP-1 and LB 6411 of Berthold the equivalent dose and environmental equivalent dose were measured. The determinate values were compared with those reported in literature and it found that are coincident inside 17%. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

    A technique to determine the isotopics of a mixed actinide sample has been proposed by measuring the coincidence of the alpha particle during radioactive decay with the conversion electron (or Auger) emitted during the relaxation of the daughter isotope. This presents a unique signature to allow the deconvolution of isotopes that possess overlapping alpha particle energy. 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. A passivated ion implanted planar silicon detector provided measurements of alpha spectroscopy. 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 to aid in the coincident measurement approach.

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

    DEFF Research Database (Denmark)

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin

    2014-01-01

    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 7.5×105 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......Pu. However, it is impossible to measure 238Pu using ICP-MS in environmental samples even a decontamination factor as high as 106 for uranium was obtained by chemical separation....

  1. First principles study of α and δ-Pu

    International Nuclear Information System (INIS)

    Chattaraj, Debabrata; Dash, Smruti

    2017-01-01

    The structural and electronic properties of α-and δ-Pu has been investigated using state of the art first principles method. All the calculations have been performed using a plane wave based pseudopotential method under the framework of spin polarized density functional theory. The effect of relativistic spin-orbit interactions on these properties has been investigated. The calculated lattice parameters are found to be within ±1% of the experimental data. The cohesive energy of α-and δ-Pu are calculated to be -3.125 and -3.126 eV/atom. The nature of chemical bonding present in those phases of Pu is depicted by calculated density of states spectra. (author)

  2. Critical mass variation of 239Pu with water dilution

    International Nuclear Information System (INIS)

    Pearlstein, S.

    1996-01-01

    The critical mass of an unreflected solid sphere of 239 Pu is ∼ 10 kg. The increase in critical mass observed for small water dilutions of unreflected 239 Pu spheres is paradoxical. Introducing small amounts of water uniformly throughout the sphere increases the spherical volume containing the same amount of 239 Pu as the critical solid sphere. The increase in radius decreases the surface-to-volume ratio of the sphere, which has the effect to first order of decreasing the neutron leakage, which is proportional to the surface, relative to the fissions, which are proportional to the volume. The reduction in neutron leakage is expected to reduce the critical mass, but instead, the critical mass is observed to increase. It is discussed how changes in the fast neutron spectrum with corresponding changes in the nuclear parameters result in an increase in critical mass for small water dilutions

  3. PU Vulpeculae at the time of spectral change in 1987

    Science.gov (United States)

    Gochermann, J.

    1991-10-01

    A flux-calibrated, low-resolution spectrum of the symbiotic variable PU Vul was obtained when it was changing from an absorption to an emission spectrum in August 1987. The spectral type of the hot component was derived from the Balmer discontinuity, the temperature derived by a Planck curve and by synthetic photometry deduced from the spectrum. A B6 Ia-Iab shell star with a temperature of 13,500 +/-300 K and reddened by interstellar extinction E(B-V) = 0.50 m was found, which harmonizes well with the expectations of Kenyon (1986) about the evolution of PU Vul. An upper limit for the distance of PU Vul was estimated as r = 5.6 +1.5/-1.1 kpc.

  4. Study of U - Pu - Fe alloys (Masurca critical experiment); Etudes d'alliages U-Pu-Fe (experience critique MASURCA)

    Energy Technology Data Exchange (ETDEWEB)

    Barthelemy, P; Boucher, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    Three compositions have been studied: 73.5 U - 25 Pu - 1.5 Fe (weight %) 74 U - 25 Pu - 1 Fe 74.5 U - 25 Pu - 0.5 Fe Elaboration and Casting are easy. After two weeks in air 74.5 U - 25 Pu - 0.5 Fe alloys are reduced in powder. As-cast alloys containing 1 and 1,5% Fe are kept undamaged during several months. A rapid oxidisation of the alloys is however observed when the samples undergo the phase transformation (at 595 deg. C and 590 deg. C respectively). Ignition tests in the presence of air show that the oxidisation starts at about 250 deg. C and that the reaction does not spread. Ignition is not observed during heating from 20 to 660 deg. C. The transformation temperature, the melting temperature and the thermal expansion coefficients have been determined by dilatometry. Below the transformation temperature, the principal phases are U-Pu zeta and (U, Pu){sub 6}Fe. Thermal conductibility, Young modulus, density and heat of fusion have been measured. Compatibility tests show that between U-Pu-Fe and stainless steel a phase of (U, Pu){sub 6}Fe type is formed. The 74 U - 25 Pu - 1% Fe alloy seems to behave better than 73.5 U - 25 Pu - 1.5% Fe alloy because the (U, Pu){sub 6}Fe layer is two or three times smaller. Finally, the thermal stability has been studied with the 74 U - 25 Pu - 1% Fe alloy. A dilatometric anomaly (very weak expansion) occurs when the sample is heated above transformation temperature and cooled. But there is no anomaly by thermal cycling from 50 deg. C to 400 deg. C and there is no deterioration of alloys by heat treatments at 100 deg. C, 200 deg. C, 300 deg. C during 5 months under vacuum. (authors) [French] Trois compositions ont ete etudiees: 73,5 U - 25 Pu - 1,5 Fe (% ponderaux) 74 U - 25 Pu - 1 Fe 74,5 U - 25 Pu - 0,5 Fe Les elaborations et mises en forme sont-faciles. Les alliages a 0,5% de fer tombent en poudre apres 15 jours d'exposition a l'air. Les alliages a 1 et 1,5% de fer, bruts de coulee, se conservent plusieurs mois. Cependant

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Toxicity of inhaled 238PuO2 II

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Merickel, B.S.; Boecker, B.B.; Hahn, F.F.; Guilmette, R.A.; Mauderly, J.L.; McClellan, R.O.

    1980-01-01

    Studies are in progress to determine dose-response relationships for inhaled 238 PuO 2 . Beagle dogs were given a single, brief, nose-only inhalation exposure to aerosols of monodisperse particles of 238 PuO 2 . Aerosols of two sizes were used, 1.5 μm aerodynamic diameter (AD) and 3.0 μm AD. Dogs were exposed to achieve initial lung burdens of 0.56, 0.28, 0.14, 0.07, 0.03 or 0.01 μCi 238 PuO 2 /kg body weight. Twelve dogs were exposed at each activity level to each aerosol particle size. The local dose around each 3.0 μm AD particle was 10 times higher than the local dose around 1.5 μm AD particles, but the dose averaged over the whole lung was the same at each activity level for both particle sizes. The lung retention of 238 Pu was divided into two phases of clearance. During the first 100 days after exposure, the average retention half-time for 238 Pu in the lung was 310 days. When the solubility changed due to particle breakup, the retention half-time decreased to 180 days during the period from 1OO to 1,500 days after exposure. The first biological effects observed were lymphopenia and neutropenia in peripheral blood. To date, 28 Beagle dogs have died at times from 536 to 1683 days after exposure. Initial lung burdens for the dead dogs ranged from 0.18 to 2.2 μCi 238 Pu/kg body weight. Nine died with radiation pneumonitis and pulmonary fibrosis, 10 died with lung tumors and 19 dogs died with bone tumors. There are 116 exposed and 22 control dogs surviving and under observation. Current patterns of dose versus response are discussed. (author)

  7. Distribution of 238Pu in tissues of fish from the canal in Miamisburg, Oho

    International Nuclear Information System (INIS)

    Kennedy, C.W.; Bartelt, G.E.

    1978-01-01

    The 238 Pu concentrations of varous tissues were measured for seven species of freshwater fish from an ecosystem containing elevated levels of 238 Pu. The highest levels of 238 Pu were found in the gastrointestinal tracts and gills, while the lowest levels were found in muscle tissue. A rapid uptake of 238 Pu was observed for hatchery bluegills introduced into this system. High plutonium concentrations in the gastrointestinal tracts and gills suggest that these organs are potential uptake sites. The presence of 238 Pu in certain tissues (liver, gonads, bone, and muscle) indicates that there is a translocation of 238 Pu from the uptake sites

  8. pH-dependent Pu interaction of one bacterial isolate from Mont Terri Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Biogeochemistry

    2016-07-01

    Sporomusa sp. MT-2.99 cells displayed a strong pH dependent affinity for Pu. Relatively high maximal Pu loadings as for instance 230 mgPu/g{sub dry} {sub biomass} for Sporomusa sp. at pH 6.1 were achieved. A much slower abiotic reduction of Pu(VI) was observed at pH 4 compared to pH 6.1. Independent on pH an enrichment of Pu(V) in the supernatant and of Pu(IV)- polymers on the biomass was discovered.

  9. Selection of bone samples for 239Pu analyses in man

    International Nuclear Information System (INIS)

    Jee, W.S.S.; Wronski, T.J.; Smith, J.M.; Kimmel, D.B.; Miller, S.C.; Stover, B.J.

    1981-01-01

    Studies on the skeletal macrodistribution, microdistribution, and toxicity of 239 Pu and studies on bone turnover rates show that trabecular bone sites with high turnover rates have the greatest affinity for 239 Pu. In the adult beagle, these high-turnover, trabecular bone sites also show a higher occurrence of osteosarcomas. Correspondingly, high-turnover bone sites in the human would include the ilium (pelvis) and lumbar vertebrae (LVB), sites that are readily obtainable at autopsy. We recommend that the trabecular bone of the ilium and of the LVB be sampled to determine the skeletal radionuclide content of humans

  10. Estimation of 239Pu in urine, influence of Sulkowich reagent

    International Nuclear Information System (INIS)

    Kalaiselvan, S.; Prasad, M.V.R.; Jeevanram, R.K.

    1988-01-01

    Plutonium is known to be co-precipitated with Sulkowich reagent as calcium ammonium oxalate. In adopting this technique for bio-assay of plutonium, its accuracy depends on the self-absorption of the resulting precipitate in each urine sample. Pu recovery experiments were carried out with varying concentration of Ca and Mg, using different volumes of Sulkowich reagent. When the sample volume is 500 ml, Pu in urine can be estimated with an accuracy and precision of 74.38%+-7.4%, with a detection limit of 0.06 Bq (1.6 pCi) per dm 3 . (author) 3 refs.; 2 figs.; 2 tabs

  11. Pu241 cross-sections below 1 keV

    International Nuclear Information System (INIS)

    Doherty, G.

    1966-12-01

    Early in 1965 a new data file (DFN 40) for Pu241 covering the energy range 10 - 4 eV to 15 MeV was prepared for the UKAEA Nuclear Data Library. The data above 1 keV are described by Douglas (AWRE 0-101/64) and the data below 1 keV are set out in this report. During the past year a number of additional measurements have been reported for Pu241 and a brief summary of these measurements and their implications for the data on the file are given. (author)

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

    International Nuclear Information System (INIS)

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

    2005-01-01

    Plutonium-239 ( 239 Pu) and plutonium-240 ( 240 Pu) activity concentrations and 240 Pu/ 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 240 Pu/ 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 240 Pu/ 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 240 Pu/ 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 240 Pu/ 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 240 Pu/ 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)

  13. Separation of U and Pu be the method of liquid chromatography with free stationary phase in TBP - white spirit - nitric acid system

    International Nuclear Information System (INIS)

    Litvina, M.N.; Malikov, D.A.; Maryutina, T.A.; Kulyako, Yu.M.; Myasoedov, B.F.

    2006-01-01

    Possibility is studied of the use of liquid chromatography with free stationary phase for U and Pu separation from organic extract obtained by direct dissolution of MOX-fuel in supercritical CO 2 containing TBP·nHNO 3 complex. As stationary phase solutions of TBP in white-spirit of different concentrations are used. Effect of composition of stationary and mobile phases on separation efficiency is investigated. It is shown that use of liquid chromatography with free stationary phase permits to separate U and Pu in conditions of TBP concentration gradient in stationary phase and HNO 3 concentration gradient in mobile one [ru

  14. FY12 Final Report for PL10-Mod Separations-PD12: Electrochemically Modulated Separation of Plutonium from Dilute and Concentrated Dissolver Solutions for Analysis by Gamma Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Sandra H.; Arrigo, Leah M.; Duckworth, Douglas C.; Cloutier, Janet M.; Breshears, Andrew T.; Schwantes, Jon M.

    2013-05-01

    Accurate and timely analysis of plutonium in spent nuclear fuel is critical in nuclear safeguards for detection of both protracted and rapid plutonium diversions. Gamma spectroscopy is a viable method for accurate and timely measurements of plutonium provided that the plutonium is well separated from the interfering fission and activation products present in spent nuclear fuel. Electrochemically modulated separation (EMS) is a method that has been used successfully to isolate picogram amounts of Pu from nitric acid matrices. With EMS, Pu adsorption may be turned “on” and “off” depending on the applied voltage, allowing for collection and stripping of Pu without the addition of chemical reagents. In this work, we have scaled up the EMS process to isolate microgram quantities of Pu from matrices encountered in spent nuclear fuel during reprocessing. Several challenges have been addressed including surface area limitations, radiolysis effects, electrochemical cell performance stability, and chemical interferences. After these challenges were resolved, 6 µg Pu was deposited in the electrochemical cell with approximately an 800-fold reduction of fission and activation product levels from a spent nuclear fuel sample. Modeling showed that these levels of Pu collection and interference reduction may not be sufficient for Pu detection by gamma spectroscopy. The main remaining challenges are to achieve a more complete Pu isolation and to deposit larger quantities of Pu for successful gamma analysis of Pu. If gamma analyses of Pu are successful, EMS will allow for accurate and timely on-site analysis for enhanced Pu safeguards.

  15. Measurement of the fission cross-section of $^{240}$Pu and $^{242}$Pu at CERN's n_TOF Facility

    CERN Multimedia

    Pavlik, A F; Gonzalez romero, E M

    The n_TOF Collaboration proposes to continue the fission program, already started in 2002-2004, taking advantage of the newly constructed Work Sector Type A, with the measurement of the two isotopes : $^{240}$ Pu and $^{242}$ Pu. They are both of major importance for reactor physics applications and are included in the Nuclear Energy Agency (NEA) High Priority List [1], in the NEA WPEC Subgroup 26 Report on the accuracy of nuclear data for advanced reactor designe [2] and in the EU 6$^{th}$ Framework Programme IP-EUROTRANS/NUDATRA reports [3]. Based on those requests, the measurement of the fission cross-section of the two Pu isotopes is one of the objectives of the project ANDES of the FP7 EURATOM program [4].

  16. Radiative neutron capture on 242Pu in the resonance region at the CERN n_TOF-EAR1 facility

    Science.gov (United States)

    Lerendegui-Marco, J.; Guerrero, C.; Mendoza, E.; Quesada, J. M.; Eberhardt, K.; Junghans, A. R.; Krtička, M.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bécares, V.; Bacak, M.; Balibrea, J.; Barbagallo, M.; Barros, S.; Bečvář, F.; Beinrucker, C.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Castelluccio, D. M.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Damone, L. A.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Furman, V.; Göbel, K.; García, A. R.; Gawlik, A.; Glodariu, T.; Gonçalves, I. F.; González-Romero, E.; Goverdovski, A.; Griesmayer, E.; Gunsing, F.; Harada, H.; Heftrich, T.; Heinitz, S.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Katabuchi, T.; Kavrigin, P.; Ketlerov, V.; Khryachkov, V.; Kimura, A.; Kivel, N.; Kokkoris, M.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lo Meo, S.; Lonsdale, S. J.; Losito, R.; Macina, D.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Matteucci, F.; Maugeri, E. A.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Montesano, S.; Musumarra, A.; Nolte, R.; Oprea, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Porras, J. I.; Praena, J.; Rajeev, K.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Rout, P. C.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Smith, A. G.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Weigand, M.; Weiss, C.; Wolf, C.; Woods, P. J.; Wright, T.; Žugec, P.; n TOF Collaboration

    2018-02-01

    The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of 242Pu there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, postirradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on 242Pu carried out at n_TOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The 242Pu(n ,γ ) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of n_TOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.

  17. Speciation of Pu(4) complexes with weak ligands from visible spectra

    International Nuclear Information System (INIS)

    Berg, J.M.; Veirs, D.K.

    2001-01-01

    Stoichiometries of early actinide metal ion complexes in solution equilibrium can sometimes be determined by modelling the dependence of a species-sensitive measurement on ligand concentration. Weak ligands present the additional problem that these measurements cannot be made in the simplifying limiting case of low ligand concentration relative to the background electrolyte. At high ligand concentrations, constant ionic strength no longer implies constant activity coefficients. Additional parameters must be included in the equilibrium model to account for the variation of activity coefficients with ligand concentration as well as with overall ionic strength. We present the formalism of such a model based on SIT theory and its implementation for simultaneous fitting of spectra over a wide range of ionic strengths. As a test case, we analyse a subset of the spectra we have collected on complexation of Pu(IV) by nitrate in aqueous acid solutions. (authors)

  18. Control of Urania Crystallite Size by HMTA-Urea Reactions in the Internal Gelation Process for Preparing (U, Pu)O2Fuel Kernels

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.

    2005-04-26

    In the development of (U,Pu)O{sub 2} kernels by the internal gelation process for the Direct Press Spheroidized process at Oak Ridge National Laboratory, a novel crystal growth step was discovered that made it possible to prepare calcined porous kernels that could be used as direct-press feed for Fast Breeder Reactor pellet fabrication. High-quality pellets were prepared that were near theoretical density and that (upon examination) revealed no evidence of sphere remnants. The controlled crystal growth step involved using hexamethylenetetramine (HMTA)-urea stock solutions that were boiled for 60 min or less. Before this discovery, all the other crystal growth steps (when utilized) could reduce the tap density to only {approx}1.3 g/cm{sup 3}, which was not sufficiently low for use in ideal pellet pressing. The use of the boiled HMTA-urea solution allowed the tap density to be lowered to 0.93 g/cm{sup 3}, with the ideal density being about 1.0 g/cm{sup 3}. This report describes the development of this technology and its scaleup.

  19. Surrogate 239Pu(n, fxn) and 241Pu(n, fxn) average fission-neutron-multiplicity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alan, B. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Akindele, O. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fisher, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-26

    We have constructed a new neutron-charged-particle detector array called NeutronSTARS. It has been described extensively in LLNL-TR-703909 [1] and Akindele et al [2]. We have used this new neutron-charged-particle array to measure the 241Pu and 239Pu fissionneutron multiplicity as a function of equivalent incident-neutron energy from 100 keV to 20 MeV. The experimental approach, detector array, data analysis, and results are summarized in the following sections.

  20. Measurements of the neutron-induced fission cross sections of 240Pu and 242Pu relative to 235U

    International Nuclear Information System (INIS)

    Behrens, J.W.; Browne, J.C.; Carlson, G.W.

    1976-01-01

    A continuation is given of the fission-cross-section ratio measurements in progress at the Lawrence Livermore Laboratory. Preliminary results are provided for the 240 Pu/ 235 U and 242 Pu/ 235 U ratios from 0.02 to 30 MeV and 0.1 to 30 MeV, respectively. Using the threshold-cross-section method, the ratios were normalized to the values 1.368 +- 0.030 and 1.116 +- 0.025, respectively, from 1.75 to 4.00 MeV

  1. Monte Carlo simulations of the stability of delta-Pu

    DEFF Research Database (Denmark)

    Landa, A.; Soderlind, P.; Ruban, Andrei

    2003-01-01

    The transition temperature (T-c) for delta-Pu has been calculated for the first time. A Monte Carlo method is employed for this purpose and the effective cluster interactions are obtained from first-principles calculations incorporated with the Connolly-Williams and generalized perturbation methods...

  2. Fractionation of (137)Cs and Pu in natural peatland.

    Science.gov (United States)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-08-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. 239,240Pu distribution in the Japanese

    International Nuclear Information System (INIS)

    Hisamatsu, Shun-ichi

    1996-01-01

    Distribution of 239,240 Pu and 241 Am in the Japanese were reviewed, and compared with those estimated with ICRP metabolic models. Inhalation and ingestion amount of these nuclides were calculated from simple models, and used as input to the ICRP metabolic models. ICRP-30 model or the combination of ICRP-66 lung model and ICRP-67 metabolic model were used for the calculation. The estimated 239,240 Pu concentrations in lung, liver, skeleton, kidney and muscle by using of the combination of ICRP-66 and 67 models agreed well with the measured data in most cases. The contribution of ingestion intake to body burden of 239,240 Pu was estimated to be 12% with 5 x 10 -4 as f 1 value. The combination of ICRP-66 and 67 model could described fairly well the organ burden of 241 Am measured in Akita and Niigata district. The 241 Am grown from 241 Pu in the human body was calculated to contribute 90% of the burden. (author)

  4. Analysis of safety margins for PuO2 containers

    International Nuclear Information System (INIS)

    Hubert, P.; Tomachevsky, E.

    1987-11-01

    In the regular manner the containers for PuO 2 transport are type B(U) and give satisfaction to the AIEA proofs. However the vigour of this conception's containers and the analysis of other radioactive containers permit to think that large safety margins exist. In this paper, the importance and the kind of these margins are studied [fr

  5. Wood fibre density measurement with 238 Pu radiation

    International Nuclear Information System (INIS)

    Barry, B.J.; Baker, D.B.

    1996-01-01

    The form of the curve of attenuation by wood fibre of the X radiation from 238 Pu has been determined. An exponential function containing a term second order in the areal density of the fibre described the curve accurately. The effect of scatter is negligible, even with an uncollimated radiation beam. (author). 18 refs., 1 tab., 6 figs

  6. Evaluation of the neutron cross sections for Pu-240

    International Nuclear Information System (INIS)

    Weston, L.W.; Arthur, E.D.

    1987-04-01

    The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for 240 Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs

  7. Mechanical properties of 238PuO2

    International Nuclear Information System (INIS)

    Petrovic, J.J.; Hecker, S.S.; Land, C.C.; Rohr, D.L.

    1977-04-01

    The mechanical properties of 238 PuO 2 have been examined in the Los Alamos Scientific Laboratory mechanical test facility built to handle α-radioactive materials. Compression tests were conducted as a function of temperature, strain rate, grain size, density, and storage time. At temperatures less than or equal to 1400 0 C, test specimens of 238 PuO 2 exhibit pseudobrittle behavior due to internal cracks. Plastic deformation is ''localized'' at the crack tips. Generalized plastic deformation is observed at 1500 0 C. Ultimate stress values decrease markedly with increasing temperature and decreasing strain rate, and decrease less with decreasing density, increasing storage time, and increasing grain size. Room temperature fracture is transgranular, whereas intergranular fracture predominates at elevated temperatures. Crack-free specimens of 239 PuO 2 exhibit extensive plastic deformation at 1000 0 C and above. The relationship of these test results to the impact properties of 238 PuO 2 fuel in radioisotope thermoelectric generators is discussed

  8. PuMA: the Porous Microstructure Analysis software

    Science.gov (United States)

    Ferguson, Joseph C.; Panerai, Francesco; Borner, Arnaud; Mansour, Nagi N.

    2018-01-01

    The Porous Microstructure Analysis (PuMA) software has been developed in order to compute effective material properties and perform material response simulations on digitized microstructures of porous media. PuMA is able to import digital three-dimensional images obtained from X-ray microtomography or to generate artificial microstructures. PuMA also provides a module for interactive 3D visualizations. Version 2.1 includes modules to compute porosity, volume fractions, and surface area. Two finite difference Laplace solvers have been implemented to compute the continuum tortuosity factor, effective thermal conductivity, and effective electrical conductivity. A random method has been developed to compute tortuosity factors from the continuum to rarefied regimes. Representative elementary volume analysis can be performed on each property. The software also includes a time-dependent, particle-based model for the oxidation of fibrous materials. PuMA was developed for Linux operating systems and is available as a NASA software under a US & Foreign release.

  9. PDF analysis of PuAl alloys local structure

    Energy Technology Data Exchange (ETDEWEB)

    Platteau, C. [CEA Valduc, 21120 Is-sur-Tille (France)], E-mail: platteau.cyril@yahoo.fr; Bruckel, P.; Ravat, B.; Delaunay, F. [CEA Valduc, 21120 Is-sur-Tille (France)

    2009-03-15

    For understanding singular properties of plutonium, there is a need in studying the average and local atomic structure in Pu alloys. To study the local structure of the {delta} phase, a pair distribution function (PDF) analysis was done and has shown some significant differences with the average structure.

  10. Second Generation Dutch Pulsar Machine - PuMa-II

    NARCIS (Netherlands)

    Karuppusamy, Ramesh; Stappers, Ben; Slump, Cornelis H.; van der Klis, Michiel

    2004-01-01

    The Second Generation Pulsar Machine (PuMa- II) is under development for the Westerbork Synthesis Radio Telescope. This is a summary of th e system design and architecture. We show that state of the art pulsar research is possible with commercially available hardware components. This approach

  11. Stabilizing And Packaging Pu Materials Per 3013 At SRS

    International Nuclear Information System (INIS)

    STEVE, HENSEL

    2005-01-01

    The Savannah River Site (SRS) began packaging Pu metals into 3013 containers in April, 2003 and oxides in October, 2003. A total of 919 outer 3013 containers were made in the FB-Line at SRS when stabilization and packaging was completed in January, 2005. Experiences, lessons learned, and an overview of packaging activities are presented

  12. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Honeyman, Bruce D.

    2006-06-01

    The overall objective of this proposed research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation to immobilization) is the role of microorganisms. The hypothesis underlying this proposal is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases, and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  13. Biogeochemical Cycling and Environmental Stability of Pu Relevant to Long-Term Stewardship of DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Arokiasamy J.; Santschi, Peter H.; Honeyman, Bruce D.

    2005-06-01

    The overall objective of this proposed research is to understand the biogeochemical cycling of Pu in environments of interest to long-term DOE stewardship issues. Central to Pu cycling (transport initiation to immobilization) is the role of microorganisms. The hypothesis underlying this proposal is that microbial activity is the causative agent in initiating the mobilization of Pu in near-surface environments: through the transformation of Pu associated with solid phases, production of extracellular polymeric substances (EPS) carrier phases, and the creation of microenvironments. Also, microbial processes are central to the immobilization of Pu species, through the metabolism of organically complexed Pu species and Pu associated with extracellular carrier phases and the creation of environments favorable for Pu transport retardation.

  14. Late effects of 239Pu administered at representative stages of gestation

    International Nuclear Information System (INIS)

    Andrew, F.D.; Sikov, M.R.

    1979-01-01

    Evaluation of effects on postnatal growth and survival times up to about 21 months following 239 Pu administration support our working hypothesis that prenatal 239 Pu exposures may adversely affect the growth and survival of the offspring

  15. 239Pu(n, 2n) and 241Pu(n, 2n) surrogate cross section measurements using NeutronSTARS

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alan, B. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Akindele, O. A. [Univ. of California, Berkeley, CA (United States); Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Koglin, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tamashiro, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oregon State Univ., Corvallis, OR (United States); Kolos, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Norman, E. B. [Univ. of California, Berkeley, CA (United States); Saastamoinen, A. [Univ. of California, Los Angeles, CA (United States); Padilla, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of California, Los Angeles, CA (United States); Fisher, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-12-08

    The goal of this project was to develop a new approach to measuring (n,2n) reactions for isotopes of interest. We set out to measure the 239Pu(n,2n) and 241Pu(n,2n) cross sections by directly detecting the 2n neutrons that are emitted. With the goal of improving the 239Pu(n,2n) cross section and to measure the 241Pu(n,2n) cross section for the first time. To that end, we have constructed a new neutron-charged-particle detector array called NeutronSTARS. It has been described extensively in Casperson et al. [1] and in Akindele et al. [2]. We have used this new neutron-charged-particle array to measure the 241Pu and 239Pu fission neutron multiplicity as a function of equivalent incident-neutron energy from 100 keV to 20 MeV. We have made a preliminary determination of the 239Pu(n,2n) and 241Pu(n,2n) cross sections from the surrogate 240Pu(α,α’2n) and 242Pu(α,α’2n) reactions respectively. The experimental approach, detector array, data analysis, and results to date are summarized in the following sections.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, Patric, E-mail: patriclindahl@yahoo.com [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Worsfold, Paul; Keith-Roach, Miranda [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Andersen, Morten B. [Bristol Isotope Group, School of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol BS8 1RJ (United Kingdom); Kershaw, Peter; Leonard, Kins [The Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Pakefield Road, Suffolk NR33 0HT (United Kingdom); Choi, Min-Seok [Division of Earth and Environmental Science, Korea Basic Science Institute, 113 Gwahangno, Yusung-gu, Daejon 305-333 (Korea, Republic of); Boust, Dominique [Laboratoire de Radioecologie, Institut de Radioprotection et de Surete Nucleaire, BP 10, 50130 Cherbourg-Octeville (France); Lesueur, Patrick [University of Caen Basse Normandie, M2C UMR CNRS 6143, 14000 Caen (France)

    2011-11-01

    A depth profile of {sup 239}Pu and {sup 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 {approx} 10 kBq kg{sup -1} was observed for {sup 239+240}Pu, corresponding to the peak in Pu discharge from Sellafield in 1973, with a decreasing trend with depth down to {approx} 0.04 kBq kg{sup -1} in the deeper layers. The depth profile of {sup 239+240}Pu specific activities together with results from gamma-ray spectrometry for {sup 137}Cs and {sup 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 {sup 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 {sup 240}Pu/{sup 239}Pu atom ratios ranged from {approx} 0.03 in the deepest layers to > 0.20 in the sub-surface layers with an activity-weighted average of 0.181. The decreasing {sup 240}Pu/{sup 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 {sup 240}Pu/{sup 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. - Highlights: {yields} Depth profiles of {sup 239}Pu and {sup 240}Pu determined in a northeastern Irish Sea sediment. {yields

  17. Study of the Effect of (U0.8Pu0.2O2 Uranium–Plutonium Mixed Fuel Fission Products on a Living Organism

    Directory of Open Access Journals (Sweden)

    Ayagoz Baimukhanova

    2016-08-01

    Full Text Available The article describes the results of experiments conducted on pigs to determine the effect of plutonium, which is the most radiotoxic and highly active element in the range of mixed fuel (U0.8Pu0.2O2 fission products, on living organisms. The results will allow empirical prediction of the emergency plutonium radiation dose for various organs and tissues of humans in case of an accident in a reactor running on mixed fuel (U0.8Pu0.2O2.

  18. Adjustment of a direct method for the determination of man body burden in Pu-239 on by X-ray detection of U-235

    International Nuclear Information System (INIS)

    Boulay, P.

    1968-04-01

    The use of Pu-239 on a larger scale sets a problem about the contamination measurement by aerosol at lung level. A method of direct measurement of Pu-239 lung burden is possible, thanks to the use of a large area window proportional counter. A counter of such pattern, has been especially carried out for this purpose. The adjustment of the apparatus allows an adequate sensibility to detect a contamination at the maximum permissible body burden level. Besides, a method for individual 'internal calibration', with a plutonium mock: the protactinium-233, is reported. (author) [fr

  19. Toxicity of 239Pu and 226Ra in young adult beagles: risk estimate in man

    International Nuclear Information System (INIS)

    Miller, S.C.

    1985-01-01

    The overall objective of this research program is to predict the risk to humans following exposure to 239 Pu. The beagle was originally selected for this program because it is relatively long-lived and has skeletal functions and structure analogous to young adults humans, simulating that of a young adult radium dial painter or occupationally exposed person. Young adult (17 month-old) beagles from the moderately inbred colony at the University of Utah were administered one intravenous injection of 239 Pu (0.0007-2.88 μCi/kg in 238 dogs) or 226 Ra (0.007-10.4 μCi/kg in 119 dogs), and compared to appropriate age-matched control beagles. All beagles have been and are being observed clinically throughout their expected 12 to 15 year post-injection lifespan. A thorough clinical and post-mortem survey is conducted to determine causes of death or lesions at death. The clinical findings are being encoded using SNOMED terminology and entered into a computerized database. All beagles in the 226 Ra study are dead and the data are being analyzed and published. The shape of the curve for dose vs. bone tumor incidence is highly linear up to average skeletal doses of 2200 rads. In higher dose groups, the time to tumor appearance is decreased and skeletal tumors occur in almost all animals. The 226 Ra response is being compared with the 239 Pu response in beagles. This toxicity ratio will allow use of the bone tumor response in the radium dial painters to predict the toxicity of plutonium for bone tumor induction in man

  20. Reduction of Pu(V) and Np(V) by leonardite humic acids and their quinonoid-enriched derivatives

    International Nuclear Information System (INIS)

    Shcherbina, N.S.; Kalmykov, St.N.; Perminova, I.V.; Kovalenko, A.N.

    2005-01-01

    Full text of publication follows: Humic substances (HS) are natural poly-electrolytes ubiquitous in aquatic environment responsible for complexation of metal ions. The presence of phenolic and quinonoid moieties in the structure of HS provide for their ability to take part in redox interactions. Capability of HS to reduce plutonium from higher oxidation states (Pu(V) and Pu(VI)) to tetravalent state was reported in several studies. However, the disparate results were reported for Np(V). The contradicting results on the redox behavior of HS could originate from the structural differences of the humic materials tested, in particular, from varying content of the redox-active quinonoid moieties. To test this hypothesis, the goal of this research was to evaluate reducing performance of leonardite humic acids and of their quinonoid-enriched derivatives with respect to Pu(V) and Np(V). The quinonoid-enriched humic derivatives were obtained using the reaction of formaldehyde co-poly-condensation between parent humic material - leonardite humic acid - and model dihydroxybenzenes - hydroquinone, catechol and 1,4-benzoquinone. The humic material: quinonoid monomer ration of 1 g per 250 mg was used. The reduction of Np(V) was studied at micro- and macro-concentration level: 10 -7 M and 10 -4 M, respectively. In case of Pu(V) the concentration was about 10 -10 M. The HS concentrations varied from 1 to 100 ppm, while ionic strength was zero. All experiments were conducted in anaerobic conditions and in the darkness. The kinetics of Pu(V) reduction was studied using solvent extraction (TTA in toluene); to monitor Np(V) reduction two independent techniques were used: solvent extraction and VIS-NIR spectrophotometry. The latter allows measuring absorbance of NpO 2 + and Np-humate complexes at 981.3 and 987.4 nm, respectively. Fast reduction of Pu(V) by the parent humic material was observed and the reduction rate increased with a decrease in pH. In case of Np(V), there was no

  1. Extraction of metals such as Pu, U and Sr with an organic solvent or a solid phase containing a cis-syn-cis isomer of the crown ether DCH18C6

    International Nuclear Information System (INIS)

    Guy, A.; Foos, J.; Lemaire, M.; Guyon, V.; Chomel, R.; Doutreluigne, P.; Le Roy, H.

    1991-01-01

    The cis-syn-cis isomer of the crown ether DCH18C6 is used in solution in an organic diluent such as benzonitrile or dichlorethane, or on a solid phase such as silica. The use of this isomer increases the extraction ratio of plutonium and strontium of solution from spent fuel reprocessing or from aqueous effluents containing Sr or Pu [fr

  2. Spatial and temporal variations of plutonium isotopes (238Pu and 239,240Pu) in sediments off the Rhone River mouth (NW Mediterranean)

    International Nuclear Information System (INIS)

    Lansard, B.; Charmasson, S.; Gasco, C.; Anton, M.P.; Grenz, C.; Arnaud, M.

    2007-01-01

    The dispersion and fate of the Rhone River inputs to the Gulf of Lions (Northwestern Mediterranean Sea) have been studied through the spatial and temporal distributions of plutonium isotopes in continental shelf sediments. Plutonium isotopes ( 238 Pu and 239,240 Pu) are appropriate tracers to follow the dispersion of particulate matter due both to their high affinity for particles and their long half-lives. In the Rhone River valley, plutonium isotopes originate from both the weathering of the catchment basin contaminated by global atmospheric fallout, and the liquid effluents released from the Marcoule reprocessing plant since 1961. This work presents a first detailed study on 238 Pu and 239,240 Pu distributions in sediments from the Rhone prodelta to the adjacent continental shelf, since the decommissioning of Marcoule in 1997. The vertical distribution of Pu isotopes has been analysed in a 4.75 m long core sampled in 2001 at the Rhone mouth. Despite this length, plutonium is found at the last 10 cm, manifesting the high sedimentation rate of the prodeltaic area and its ability for trapping fine-grained sediments and associated contaminants. The highest 238 Pu and 239,240 Pu concentrations reached 1.26 and 5.97 Bq kg -1 respectively and were found within the layer 280-290 cm. The 238 Pu/ 239,240 Pu activity ratios (AR) demonstrated an efficient and huge trapping of the Pu isotopes derived from Marcoule. The fresh sediments, located on the top of the core, show lower plutonium activity concentrations and lower 238 Pu/ 239,240 Pu ratios. This decrease is in close relation with the shut down of the Marcoule reprocessing plant in 1997. In 2001, plutonium isotopes were also analysed in 21 surface sediments located offshore and concentrations ranged from 0.03 to 0.17 Bq kg -1 for 238 Pu and from 0.33 to 1.72 Bq kg -1 for 239,240 Pu. The 238 Pu/ 239,240 Pu AR ranged from 0.24 close to the river mouth to 0.06 southwards, indicating the decreasing influence of the

  3. Disposition of 238Pu(NO3)4 following inhalation by beagle dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.; Cannon, W.C.; Schirmer, R.E.; Stevens, D.L. Jr.

    1979-01-01

    Twelve dogs were given a single inhalation exposure to 238 Pu(NO 3 ) 4 to study deposition and translocation up to 1 yr. Preliminary data suggest a greater and more rapid translocation of 238 Pu(NO 3 ) 4 to bone and liver than was observed for 239 Pu(NO 3 ) 4

  4. Subcellular binding of 239Pu in the liver of selected species of rodents

    International Nuclear Information System (INIS)

    Winter, R.

    1980-01-01

    The subcellular distribution of 239 Pu in the liver of selected rodent species was investigated as well as the relation between 239 Pu and the iron metabolism. The goal of the investigation was to find out why the liver discharge of 239 Pu from the liver varies so much between species. (orig.) [de

  5. 238Pu fuel form processes. Final report, January-September 1983

    International Nuclear Information System (INIS)

    Mosley, W.C.; Taylor, D.H.

    1983-01-01

    Progress is reported on the following: analytical studies of weld-quench cracking in DOP-26 iridium alloy, iridium/ 238 PuO 2 compatibility test, surface area measurements of 238 PuO 2 using the Blaine air permeability apparatus, and helium release from 238 PuO 2

  6. Detection of Pu in Pacific Ocean water with AMS related to the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Guzman, Jose Manuel; Korschinek, Gunther; Kortmann, Florian; Lierse v Gostomski, Christoph; Ludwig, Peter [TUM (Germany); Golser, Robin; Steier, Peter [Universitaet Wien (Austria); Yamada, Masatoshi [Hirosaki University (Japan)

    2016-07-01

    The concentration of plutonium (Pu) and its isotopic ratios were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples. The isotopic ratios {sup 240}Pu/{sup 239}Pu and {sup 241}Pu/{sup 239}Pu can be used to identify a possible release of Pu into the ocean by the Fukushima accident. {sup 241}Pu from fallout of nuclear weapon testings has already significantly decayed. {sup 241}Am, the daughter nuclide of {sup 241}Pu, causes isobaric background on {sup 241}Pu in mass-spectrometric measurements. Therefore, Am and Pu had to be separated chemically using extraction chromatography. The method was verified by analyzing certified reference material. 12 sea water samples, collected at different depths, were prepared at the Radiochemie Muenchen. The concentration of Pu was measured with AMS at the Maier-Leibnitz-Laboratory in Munich and the Vienna Environmental Research Laboratory (VERA). After a short motivation related to the Fukushima accident, the chemical separation method will be presented. Preliminary results of the distribution of Pu in ocean water will be discussed.

  7. Composite fuels. Defining a strategy for better Pu utilization in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Porta, Jacques; Baldi, Stefano [DRN/DER/SIS CE Cadarache Bat. 211, 13108 St. Paul lez Durance CEDEX (France); Puill, Andre; Aillaud, Cecile

    1999-07-01

    After a description of the French context dominated by the accumulation of plutonium, and the international context in which the tendency is towards the disappearance of plutonium reserves and the destruction of minor actinides, a few solutions selected in the framework of the Innovating Fuels programme are presented. The aim is to burn the surplus Pu by means of fuel in inert matrices since, in addition to the increased burnup, the absence of plutonium generating conversion must be considered. The experiments intended to qualify selected CERCERs and CERMETs are presented and discussed, the feasibility of CERMET UO2 and MOX cores is established. Things are more complicated for PuO2 CERMET and we show that, in order to optimize loading, a dedicated heterogeneous assembly has to be defined. The Advanced Plutonium Assembly (APA) is presented. The last part of this article is devoted to the first fabrication tests on these very particular fuels and to the definition of reference accidents liable to affect 'cold' fuels such as CERMETs. (author)

  8. Composite fuels. Defining a strategy for better Pu utilization in PWRs

    International Nuclear Information System (INIS)

    Porta, Jacques; Baldi, Stefano; Puill, Andre; Aillaud, Cecile

    1999-01-01

    After a description of the French context dominated by the accumulation of plutonium, and the international context in which the tendency is towards the disappearance of plutonium reserves and the destruction of minor actinides, a few solutions selected in the framework of the Innovating Fuels programme are presented. The aim is to burn the surplus Pu by means of fuel in inert matrices since, in addition to the increased burnup, the absence of plutonium generating conversion must be considered. The experiments intended to qualify selected CERCERs and CERMETs are presented and discussed, the feasibility of CERMET UO2 and MOX cores is established. Things are more complicated for PuO2 CERMET and we show that, in order to optimize loading, a dedicated heterogeneous assembly has to be defined. The Advanced Plutonium Assembly (APA) is presented. The last part of this article is devoted to the first fabrication tests on these very particular fuels and to the definition of reference accidents liable to affect 'cold' fuels such as CERMETs. (author)

  9. Thermodynamic stabilities of MO2+x(s) (M = U, Np, Pu and Am), pourbaix diagrams

    International Nuclear Information System (INIS)

    Vitorge, Pierre; Faure, Marie-Helene; Vercouter, Thomas; Capdevila, Helene; Maillard, Serge

    2002-01-01

    The experimental solubilities of the hydrated amorphous freshly precipitated M(OH) z (am) and MO 2 (OH) z (am) compounds are often used as an upper limit for the safety assessments of deep waste repositories, since these compounds slowly transform to less soluble ones, as typically M(OH) 4 (am) to MO 2 (cr). Solubility (vs. redox potential) at pH=8, and E-pH predominance diagrams are plotted in aqueous solutions at 25degC by using thermodynamic data recently selected by the NEA-TDB review, or estimated by using classical chemical analogies for the non-redox reactions. The solubilities and relative stabilities are also calculated for the MO 2+x (s) crystalline compounds of known stabilities: U 4 O 9 (s), U 3 O 7 (s), U 3 O 8 (s) and Np 2 O 5 (s) where 2+x = 2.25, 2.33, 2.67 and 2.5 respectively. The stabilities of the other MO 2+x (s) compounds are estimated by analogy: M 4 O 9 (s) (M=U, Np, Pu), M 3 O 7 (s) and M 3 O 8 (s) (M=U, Pu), and M 2 O 5 (s) (M=Np, Am) are predicted to be more stable (i.e. less soluble), than the amorphous hydroxides. However their precipitation have never been observed at room temperature possibly for kinetic reasons or difficulties in interpreting solubility experiments. (author)

  10. Radiolysis of aqueous solution of plutonium; Radiolyse des solutions aqueuses de plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Pages nee Flon, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-07-01

    This study is concerned first with the effects of gamma rays on plutonium aqueous solutions at various valency states, in presence of sulfuric, perchloric, nitric and hydrochloric acids. The main feature is the reduction of Pu VI into Pu V, followed by dismutation from V to IV and VI. For sulfuric and perchloric acid solutions (0,2 N) the following process is given: radiolysis of water produces OH, H{sub 2}O{sub 2}, H and H{sub 2}. H and H{sub 2}O{sub 2} reduce Pu VI while Pu V is oxidised by OH radicals. However the reaction of hydrogen peroxide is slow and leads to an after effect. A parallel study of the action of H{sub 2}O{sub 2} has given a confirmation. Spectrophotometric measurements were carried out on disappearance of Pu VI and formation of Pu IV and it was possible to make determination of G{sub H{sub 2}}{sub O{sub 2}} = 0,8 and G{sub H} - G{sub OH} = 0,8. G{sub H{sub 2}} = 0,41 was measured by gas analysis. The calculation of G{sub {sup -}}{sub H{sub 2}}{sub O} gave 4,35. The re-oxidation of Pu V is dependant on the concentration of sulfate ions. In perchloric acid solution reduction goes on to Pu Ill. Cl{sup -} and NO{sub 3}{sup -} ions inhibit the reduction and even suppress it. The effect of alpha particles both from plutonium and from polonium is very similar to the effect of hydrogen peroxyde. Induction time were observed mainly in presence of HSO{sub 4}{sup -}, depending on the accumulation of H{sub 2}O{sub 2} and (or) of plutonium peroxide. At low acidities, Pu IV peroxide seems to lead to polymer forms. In the more simple cases (H{sub 2}SO{sub 4} and HClO{sub 4} 0,2N), the following yields were found: G (equivalent reduced) = 3.2, G{sub H{sub 2}}{sub O{sub 2}} = 1.35, G{sub H{sub 2}} = 1.6 and G{sub H} - G{sub OH} = 0.1, assuming G{sub HO{sub 2}} = 0.2; and the usual hypothesis on radiolysis of water by alpha particles. Radiation induced oxidation of Pu III into Pu IV was also observed in H{sub 2}SO{sub 4} and HNO{sub 3} aqueous solutions, and

  11. Optimization and validation of Folin-Ciocalteu method for the determination of total polyphenol content of Pu-erh tea.

    Science.gov (United States)

    Musci, Marilena; Yao, Shicong

    2017-12-01

    Pu-erh tea is a post-fermented tea that has recently gained popularity worldwide, due to potential health benefits related to the antioxidant activity resulting from its high polyphenolic content. The Folin-Ciocalteu method is a simple, rapid, and inexpensive assay widely applied for the determination of total polyphenol content. Over the past years, it has been subjected to many modifications, often without any systematic optimization or validation. In our study, we sought to optimize the Folin-Ciocalteu method, evaluate quality parameters including linearity, precision and stability, and then apply the optimized model to determine the total polyphenol content of 57 Chinese teas, including green tea, aged and ripened Pu-erh tea. Our optimized Folin-Ciocalteu method reduced analysis time, allowed for the analysis of a large number of samples, to discriminate among the different teas, and to assess the effect of the post-fermentation process on polyphenol content.

  12. Historical changes in 239Pu and 240Pu sources in sedimentary records in the East China Sea: Implications for provenance and transportation

    DEFF Research Database (Denmark)

    Wang, Jinlong; Baskaran, Mark; Hou, Xiaolin

    2017-01-01

    from 0.158 to 0.297 and were mostly higher than the mean global fallout value of 0.18. The 239,240Pu inventories in the ECS varied widely, from 2 to 807 Bqm−2, with the highest values commonly found in the coastal areas. In the Yangtze Estuary, the mean 239+240Pu activity concentration is close...... to the estimated value of the suspended material from the Yangtze River catchment (0.18 Bqkg−1), and the 240Pu/239Pu atom ratio was found to be ∼0.18, which indicates that the Yangtze River input is the dominant source of Pu for this area. The total annual Yangtze River input of 239+240Pu was estimated to be 2...

  13. Effect of TiO2 additive on the sintering of nuclear fuel (U,Pu)O2. Contribution of surface diffusion to plutonium distribution

    International Nuclear Information System (INIS)

    Bremier, Stephane

    1997-01-01

    concentration in order to obtain a homogeneous (U,Pu)O 2 solid solution independently of the degree of heterogeneity of the initial oxide mixtures

  14. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  15. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2009-01-01

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10 -10 nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  16. {sup 137}Cs, {sup 239+240}Pu concentrations and the {sup 240}Pu/{sup 239}Pu atom ratio in a sediment core from the sub-aqueous delta of Yangtze River estuary

    Energy Technology Data Exchange (ETDEWEB)

    Pan, S.M., E-mail: span@nju.edu.cn [Key Lab of Ministry of Education of Coast and Island Development, Nanjing University, Nanjing 210093 (China); Tims, S.G. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Liu, X.Y. [Key Lab of Ministry of Education of Coast and Island Development, Nanjing University, Nanjing 210093 (China); Fifield, L.K. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2011-10-15

    A sediment core collected from the sub-aqueous delta of the Yangtze River estuary was subjected to analyses of {sup 137}Cs and plutonium (Pu) isotopes. The {sup 137}Cs was measured using {gamma}-spectrometry at the laboratories at the Nanjing University and Pu isotopes were determined with Accelerator Mass Spectrometry (AMS), measurements made at the Australian National University. The results show considerable structure in the depth concentration profiles of the {sup 137}Cs and {sup 239+240}Pu. The shape of the vertical {sup 137}Cs distribution in the sediment core was similar to that of the Pu. The maximum {sup 137}Cs and {sup 239+240}Pu concentrations were 16.21 {+-} 0.95 mBq/g and 0.716 {+-} 0.030 mBq/g, respectively, and appear at same depth. The average {sup 240}Pu/{sup 239}Pu atom ratio was 0.238 {+-} 0.007 in the sediment core, slightly higher than the average global fallout value. The changes in the {sup 240}Pu/{sup 239}Pu atom ratios in the sediment core indicate the presence of at least two different Pu sources, i.e., global fallout and another source, most likely close-in fallout from the Pacific Proving Grounds (PPG) in the Marshall Islands, and suggest the possibility that Pu isotopes are useful as a geochronological tool for coastal sediment studies. The {sup 137}Cs and {sup 239+240}Pu inventories were estimated to be 7100 {+-} 1200 Bq/m{sup 2} and 407 {+-} 27 Bq/m{sup 2}, respectively. Approximately 40% of the {sup 239+240}Pu inventory originated from the PPG close-in fallout and about 50% has derived from land-origin global fallout transported to the estuary by the river. This study confirms that AMS is a useful tool to measure {sup 240}Pu/{sup 239}Pu atom ratio and can provide valuable information on sedimentary processes in the coastal environment.

  17. Quantitative dissolution of (U, Pu)O2 MOX (0.4% to 44% PuO2) using microwave heating technique

    International Nuclear Information System (INIS)

    Malav, R.K.; Fulzele, Ajit K.; Prakash, Amrit; Afzal, Md.; Panakkal, J.P.

    2011-01-01

    AFFF has fabricated the (U, Pu)O 2 mixed oxide fuels for PHWRs, BWRs, PFBRs and FBTRs. The quantitative dissolution of the fuel samples are required within time for accurate determination of uranium-plutonium in chemical quality control laboratory. This paper describes the use of microwave heating technique in quantitative dissolution of (U, Pu)O 2 MOX (from 0.4% to 44% PuO 2 ). (author)

  18. Measurement of acidity and density of plutonium solutions

    International Nuclear Information System (INIS)

    Hofstetter, K.J.; Bowers, D.L.; Kemmerlin, R.P.

    1978-01-01

    The solutions were analyzed for acidity and total Pu concentration at ambient temperature while the density was determined at 25, 35, 45, and 60 0 C. From least squares fitting, it was found that the density could be computed to within 1% of the experimental value using the equation D = 1 + 0.0477[H + ] - 4.25 x 10 -3 [H + ] 2 + 1.477 x 10 -3 [Pu] - (T - 25)/1000

  19. Nondestructive assay instrument for measurement of plutonium in solutions

    International Nuclear Information System (INIS)

    Shirk, D.G.; Hsue, F.; Li, T.K.; Canada, T.R.

    1979-01-01

    A nondestructive assay (NDA) instrument that measures the 239 Pu content in solutions, using a passive gamma-ray spectroscopy technique, has been developed and installed in the LASL Plutonium Processing Facility. A detailed evaluation of this instrument has been performed. The results show that the instrument can routinely determine 239 Pu concentrations of 1 to 500 g/l with accuracies of 1 to 5% and assay times of 1 to 2 x 10 3 s

  20. Identification of Nilsson orbitals in the superdeformed minimum of {sup 237}Pu

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Thomas James

    2008-03-31

    -particle calculations, Nilsson model and Woods-Saxon potential calculations. This comparison allowed for the first time an assignment of the Nilsson quantum numbers. In the course of this thesis the 5/2{sup +}[862] and 9/2{sup +}[624] Nilsson single-particle states were identified for the ground states of the two isomers in {sup 237f}Pu as well as 3/2{sup -}[512] and 7/2{sup -}[514] for excited rotational bands, for the first time based on calculations reproducing the deformed magic neutron number N=146. The identification of Nilsson orbitals will provide an important input for the validation and improvement of theoretical nuclear models and will lead to improved predictions for fission barriers and their extrapolations to neutron-rich heavy elements in the mass region of the r-process path of the astrophysical nucleosynthesis. (orig.)

  1. Identification of Nilsson orbitals in the superdeformed minimum of 237Pu

    International Nuclear Information System (INIS)

    Morgan, Thomas James

    2008-01-01

    comparison allowed for the first time an assignment of the Nilsson quantum numbers. In the course of this thesis the 5/2 + [862] and 9/2 + [624] Nilsson single-particle states were identified for the ground states of the two isomers in 237f Pu as well as 3/2 - [512] and 7/2 - [514] for excited rotational bands, for the first time based on calculations reproducing the deformed magic neutron number N=146. The identification of Nilsson orbitals will provide an important input for the validation and improvement of theoretical nuclear models and will lead to improved predictions for fission barriers and their extrapolations to neutron-rich heavy elements in the mass region of the r-process path of the astrophysical nucleosynthesis. (orig.)

  2. Estimation of human gonadal Pu and Ce concentrations from animal data

    International Nuclear Information System (INIS)

    Thomas, R.G.; Durbin, P.W.; McInroy, J.F.; Healy, J.W.

    1989-01-01

    Data were obtained from the literature for gonad and body weights and for the Pu or Ce content of the gonads and body at death for several laboratory animal species, five human Pu injection cases, and 731 human adults exposed environmentally to Pu in fallout. Data for Pu concentration in gonads, liver, and bone samples of 59 male and five female occupational Pu cases (including four completely analyzed whole bodies) were obtained from the U.S. Transuranium Registry. A logarithmic function was used to relate fractional Pu or Ce concentration in testes and ovaries to body weight of the animals and to predict fractional Pu or Ce concentrations in human gonads, [Pu]G . PuB-1 = aBWb, where [Pu]G or [Ce]G is the nuclide concentration in gonads (Bq g-1 of wet weight), PuB or CeB is the nuclide content of the body at death, and BW is body weight (kg). The fractional Pu and Ce concentrations in both the testes and ovaries are inverse and nearly linear functions of body weight. The regression lines of fractional Pu or Ce concentration in testes and ovaries have similar slopes (b = -1.07 +/- 0.14); however, the nuclide concentrations (coefficient a) in ovaries are six times greater than in testes. Extrapolation of the animal data yielded fractional Pu concentrations in human testes and ovaries that agree with those calculated for the occupational cases and those recommended by the International Commission on Radiological Protection. The good agreement between the fractional concentrations of Pu and Ce in the testes and in the ovaries suggests that these data can be substituted in metabolic models of chemically similar elements for which gonadal data are scarce

  3. Structural, magnetic, electronic and optical properties of PuC and PuC{sub 0.75}: A hybrid density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rong [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); College of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Tang, Bin [School of Business Administration, Chongqing City Management College, Chongqing 401331 (China); Gao, Tao, E-mail: gaotao@scu.edu.cn [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Ao, BingYun, E-mail: aobingyun@caep.cn [Science and Technology on Surface Physics and Chemistry Laboratory, P.O. Box 718-35, Mianyang 621907 (China)

    2016-05-15

    We perform first principles calculations to investigate the structural, magnetic, electronic and optical properties of PuC and PuC{sub 0.75}. Furthermore, we examine the influence of carbon non-stoichiometry on plutonium monocarbide. For the treatment of strongly correlated electrons, the hybrid density functionals like PBE0, Fock-0.25 are used and we compare the results with the generalized gradient approximation (GGA), local density approximation (LDA), LDA + U and experimental ones. The optimized lattice constant a{sub 0} = 4.961 Å for PuC in the Fock-0.25 scheme is the most close to the experimental data. The ground states of PuC and PuC{sub 0.75} are found to be anti-ferromagnetic. Our results indicate that additional removal of a C atom make lattice contract and new DOS peak appear in the near-Fermi region. We also compute and compare the optical properties of PuC and PuC{sub 0.75}. The difference in optical properties between PuC and PuC{sub 0.75} should also be the influence of carbon vacancies.

  4. Transport process of Pu isotope in marginal seas of the western North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, 036-8564, Aomori (Japan); Zheng, Jian [Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, 263-8555, Chiba (Japan)

    2014-07-01

    Significant quantities of Pu isotopes have been released into the marine environment as the result of atmospheric nuclear weapons testing. Most radionuclides globally dispersed in atmospheric nuclear weapons testing were released into the environment during the 1950's and 1960's. In the western North Pacific Ocean, the principal source can be further distinguished as two distinct sources of Pu: close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds (PPG) in the Marshall Islands and global stratospheric fallout. Since the {sup 240}Pu/{sup 239}Pu atom ratio is characteristic for the Pu emission source, information on Pu isotopic signature is very useful to better understand the transport process in the oceans and to identify the sources of Pu. The mean atom ratio of {sup 240}Pu/{sup 239}Pu from the global stratospheric fallout is 0.180 ±0.014 based on soil sample data, whereas that from close-in tropospheric fallout from the PPG is 0.33 - 0.36. The {sup 240}Pu/{sup 239}Pu atom ratios in seawater samples collected in marginal seas of the western North Pacific Ocean will provide important and useful data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The objectives of this study were to measure the {sup 239+240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios in seawater from the Sea of Okhotsk, Japan Sea, South China Sea and Sulu Sea and to discuss the transport process of Pu. Large-volume seawater samples (250 L each) were collected from the surface to the bottom in marginal seas of the western North Pacific Ocean with acoustically triggered quadruple PVC sampling bottles during the R/V Hakuho-Maru cruise. The {sup 239}Pu and {sup 240}Pu concentrations and {sup 240}Pu/{sup 239}Pu atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. In

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

    International Nuclear Information System (INIS)

    Palmiottti, G.; Hiruta, H.; Salvatores, M.

    2011-01-01

    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 235 U, 238 U, and 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: 235 U and 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 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.

  6. Transuranic advanced disposal systems: preliminary 239Pu waste-disposal criteria for Hanford

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Napier, B.A.; Soldat, J.K.

    1982-08-01

    An evaluation of the feasibility and potential application of advanced disposal systems is being conducted for defense transuranic (TRU) wastes at the Hanford Site. The advanced waste disposal options include those developed to provide greater confinement than provided by shallow-land burial. An example systems analysis is discussed with assumed performance objectives and various Hanford-specific disposal conditions, waste forms, site characteristics, and engineered barriers. Preliminary waste disposal criteria for 239 Pu are determined by applying the Allowable Residual Contamination Level (ARCL) method. This method is based on compliance with a radiation dose rate limit through a site-specific analysis of the potential for radiation exposure to individuals. A 10,000 year environmental performance period is assumed, and the dose rate limit for human intrusion is assumed to be 500 mrem/y to any exposed individual. Preliminary waste disposal criteria derived by this method for 239 Pu in soils at the Hanford Site are: 0.5 nCi/g in soils between the surface and a depth of 1 m, 2200 nCi/g of soil at a depth of 5 m, and 10,000 nCi/g of soil at depths 10 m and below. These waste disposal criteria are based on exposure scenarios that reflect the dependence of exposure versus burial depth. 2 figures, 5 tables

  7. Performance of U-Pu-Zr fuel cast into zirconium molds

    International Nuclear Information System (INIS)

    Crawford, D.C.; Lahm, C.E.; Tsai, H.

    1992-10-01

    U-3Zr and U-20.5Pu-3Zr were injection cast into Zr tubes, or sheaths, rather than into quartz molds and clad in 316SS. These elements and standard-cast U-l0Zr and U-IgPu-l0Zr elements were irradiated in EBR-II to 2 at.% and removed for interim examination. Measurements of axial growth at indicate that the Zr-sheathed elements exhibited significantly less axial elongation than the standard-cast elements (1.3 to 1.8% versus 4.9 to 8.1%). Fuel material extruded through the ends of the Zr sheaths. allowing the low-Zr fuel to contact the cladding in some cases. Transverse metallographic sections reveal cracks in the Zr sheath through which fuel extruded and contacted cladding. The sheath is not a sufficient barrier between fuel and cladding to reduce FCCI. and any adverse effects due to increased FCCI will be evident as the elements attain higher burnup

  8. The European experience in safeguarding nuclear fuel recycle processes and Pu stores

    International Nuclear Information System (INIS)

    Synetos, Sotiris

    2013-01-01

    Civil nuclear programs in the European Union member states have from their onset included fuel recycling as an option. The EURATOM Treaty gives to the European Commission the obligation to apply safeguards controls to all civil Nuclear Material in the European Union, and to facilitate the implementation of IAEA safeguards. The European Commission (EURATOM) has thus gained years of experience in safeguarding reprocessing plants, Pu storages, and MOX fuel fabrication plants and is currently participating in the development of approaches and measures for safeguarding long term repositories. The aim of this paper is to present the regulator's views and experience on safeguarding nuclear fuel recycle processes and Pu stores, which is based on the following principles: -) Early involvement of the control organizations in the design of the safeguards measures to be developed for a plant (currently referred to as Safeguards by Design); -) Early definition of a safeguards strategy including key measurement points; -) The design and development of plant specific Safeguards equipment, including an on site laboratory for sample analysis; -) The development by the operator of an appropriate Nuclear Material accountancy system to facilitate their declaration obligations; -) The introduction of an inspection regime allowing comprehensive controls under the restrictions imposed by financial and Human Resources limitations; -) Optimization of the inspection effort by using unattended measuring stations, containment and surveillance systems and secure remote transmission of data to the regulator's headquarters. The paper is followed by the slides of the presentation. (authors)

  9. Variations in Pu isotopic composition in soils from the Spitsbergen (Norway): Three potential pollution sources of the Arctic region.

    Science.gov (United States)

    Łokas, E; Anczkiewicz, R; Kierepko, R; Mietelski, J W

    2017-07-01

    Although the polar regions have not been industrialised, numerous contaminants originating from human activity are detectable in the Arctic environment. This study reports evidence of 240 Pu/ 239 Pu atomic ratios in the tundra and initial soils from different parts of west and central Spitsbergen and recognizes possible environmental inputs of non-global fallout Pu. The average atomic ratio of 240 Pu/ 239 Pu equal to 0.179 (ranging between 0.129 and 0.201) in tundra soils are comparable to the characteristic ratio for global fallout (0.180). However, the 240 Pu/ 239 Pu atomic ratios in the initial soils from proglacial zone of glaciers change within wide range between 0.1281 and 0.234 with the mean value of 0.169. By combining alpha and mass spectrometry, the three-sources model was used to identify the Pu sources in initial soils. Our study indicated that the main source of Pu is nuclear tests and that a second source with lower Pu ratio may come from weapons grade Pu (unexploded weapons grade Pu ie. material from bomb which didn't undergo nuclear explosions for example for security tests). Additionally, we found samples with high 238 Pu/ 239+240 Pu activity ratios and with typical global fallout 240 Pu/ 239 Pu atomic ratios, which are associated with separate sources of pure 238 Pu from the SNAP-9A satellite burn up in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Inhaled 239PuO2 in rats with pulmonary emphysema

    International Nuclear Information System (INIS)

    Lundgren, D.L.; Mauderly, J.L.; Hahn, F.F.

    1984-01-01

    The modifying effects of a pre-existing lung disease (emphysema) on the deposition, distribution, retention, and effects of inhaled 239 PuO 2 in the rat are being investigated. Preliminary observations indicated that the deposition and retention patterns for 239 Pu particles inhaled by rats with emphysema and control rats were similar, but the distribution of inhaled 239 Pu immediately after exposure was different. Respiratory function measured through one year after exposure to 239 Pu was consistent with emphysema and was not altered by the 239 Pu lung burden. Long-term observations are continuing. 4 references, 2 tables

  11. Effect of Pu-rich agglomerate in MOX fuel on a lattice calculation

    International Nuclear Information System (INIS)

    Kawashima, Katsuyuki; Yamamoto, Toru; Namekawa, Masakazu

    2007-01-01

    The effect of Pu-rich agglomerates in U-Pu mixed oxide (MOX) fuel on a lattice calculation has been demonstrated. The Pu-rich agglomerate parameters are defined based on the measurement data of MIMAS-MOX and the focus is on the highly enriched MOX fuel in accordance with increased burnup resulting in a higher volume fraction of the Pu-rich agglomerates. The lattice calculations with a heterogeneous fuel model and a homogeneous fuel model are performed simulating the PWR 17x17 fuel assembly. The heterogeneous model individually treats the Pu-rich agglomerate and U-Pu matrix, whereas the homogeneous model homogenizes the compositions within the fuel pellet. A continuous-energy Monte Carlo burnup code, MVP-BURN, is used for burnup calculations up to 70 GWd/t. A statistical geometry model is applied in modeling a large number of Pu-rich agglomerates assuming that they are distributed randomly within the MOX fuel pellet. The calculated nuclear characteristics include k-inf, Pu isotopic compositions, power density and burnup of the Pu-rich agglomerates, as well as the pellet-averaged Pu compositions as a function of burnup. It is shown that the effect of Pu-rich agglomerates on the lattice calculation is negligibly small. (author)

  12. Electronic structure of α- and δ-Pu from photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Arko, A. J.; Joyce, J. J.; Morales, L.; Wills, J.; Lashley, J.; Wastin, F.; Rebizant, J.

    2000-01-01

    We report photoemission results on α- and δ-Pu using a laser plasma light source (LPLS) as well as He light as the exciting radiation. The LPLS is a pseudocontinuum tunable light source with intensities rivaling some second-generation synchrotrons. Both phases of Pu display a narrow, temperature-independent, 5f-related feature at the Fermi energy, which is narrower in δ-Pu than in α-Pu, suggestive of possible heavy-fermion-like behavior. In both α-Pu and δ-Pu the photon-energy dependence of this feature suggests some 6d admixture, albeit somewhat smaller in δ-Pu. In this respect it differs qualitatively from Ce and U heavy fermions. (c) 2000 The American Physical Society

  13. Determination of Pu, Am and Cm in Environmental Samples

    Energy Technology Data Exchange (ETDEWEB)

    Lujaniene, G. [SRI Centre for Physical Sciences and Technology, Vilnius (Lithuania)

    2013-07-15

    The determination of actinides in the environmental samples at a lower detection limit is required for monitoring purposes and for environmental research. The method for Pu, Am and Cm measurements in soil and sediment samples provides high recoveries and good decontamination from interfering radionuclides. The main steps of the method involve digestion of the samples, separation of radionuclides from matrix using the TOPO /cyclohexane extraction and final purification using extraction Eichrom resins (TEVA, TRU). The accuracy and precision of Pu, Am and Cm analyses were tested using IAEA RM No 135, NIST SRM No 4350b, No 4357 and in intercomparison runs organized by the Riso National Laboratory, Denmark, and in the proficiency tests organized by National Physical Laboratory, UK. The method was applied for measurement of radionuclides in aerosol samples (ashes {approx}30 g), bottom sediments (50-80 g dr. wt) and soil (including Chernobyl soil) samples. (author)

  14. Antioxidant Phenolic Compounds from Pu-erh Tea

    Directory of Open Access Journals (Sweden)

    Shu Shan Du

    2012-11-01

    Full Text Available Eight compounds were isolated from the water extract of Pu-erh tea and their structures were elucidated by NMR and MS as gallic acid (1, (+-catechin (2, (−-epicatechin (3, (−-epicatechin-3-O-gallate (4, (−-epigallocatechin-3-O-gallate (5, (−-epiafzelechin- 3-O-gallate (6, kaempferol (7, and quercetin (8. Their in vitro antioxidant activities were assessed by the DPPH and ABTS scavenging methods with microplate assays. The relative order of DPPH scavenging capacity for these compounds was compound 8 > compound 7 > compound 1 > compound 6 > compound 4 ≈ compound 5 > compound 2 > VC (reference > compound 3, and that of ABTS scavenging capacity was compound 1 > compound 2 > compound 7 ≈ compound 8 > compound 6 > compound 5 > compound 4 > VC (reference > compound 3. The results showed that these phenolic compounds contributed to the antioxidant activity of Pu-erh tea.

  15. Thermodynamic database development: Al-Am-Ga-Pu-U

    Energy Technology Data Exchange (ETDEWEB)

    Perron, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences; Turchi, P. E. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences; Landa, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences; Soderlind, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences

    2014-03-17

    The goal of this study is about the thermodynamic re-assessment of the Plutonium- Uranium (Pu-U) system as a first step leading to the development of a plutonium-based thermodynamic database (i.e., Pu with Al, Am, Ga, Mo, U…) with resulting phase diagrams and associated thermodynamic data. Indeed, phase stability trends and phase diagrams of multi-component nuclear materials are crucial for predicting properties and performance under normal, hypothetical or even accidental conditions. This work is based on a coupling between ab initio energetics, phenomenological thermodynamics models - based on the CALPHAD (CALculation of PHAse Diagrams) approach - and the use of the Thermo-Calc software, together with experimental data (whenever available). The present report summarizes results obtained (quarter period: 10/07/2013-01/07/2014) under the auspices of an agreement between CEA/DAM and NNSA/DP on cooperation in fundamental science supporting stockpile stewardship (P182).

  16. Design of a Pu-238 waste incineration process

    International Nuclear Information System (INIS)

    Charlesworth, D.L.; McCampbell, R.B.

    1985-01-01

    Combustible 238 Pu waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant and is being retrievably stored at the Plant. As part of the long-term plan to process the stored waste and current waste in preparation for future disposition, a 238 Pu incinceration process is being cold-tested at SRL. The incineration process consists of a continuous-feed preparation system, a two-stage, electrically fired incinerator, and a filtration off-gas system. Process equipment has been designed, fabricated, and installed for nonradioactive testing and cold run-in. Design features to maximize the ability to remotely maintain the equipment were incorporated into the process. Interlock, alarm, and control functions are provided by a programmable controller. Cold testing is scheduled to be completed in 1986

  17. 238Pu - Comments on Evaluation of Decay Data

    International Nuclear Information System (INIS)

    Chechev, V. P.

    2013-01-01

    This evaluation was done originally in March 2003, corrected in June 2004, and then updated in June 2009 with a literature cut-off by the same date. Decay Scheme: The decay scheme is based on 2007Br04. Some expected weak gamma-ray transitions were not observed directly in 238 Pu α-decay but have been adopted from decay of 234 Pa and 234 Np

  18. Time-sensitive Customer Churn Prediction based on PU Learning

    OpenAIRE

    Wang, Li; Chen, Chaochao; Zhou, Jun; Li, Xiaolong

    2018-01-01

    With the fast development of Internet companies throughout the world, customer churn has become a serious concern. To better help the companies retain their customers, it is important to build a customer churn prediction model to identify the customers who are most likely to churn ahead of time. In this paper, we propose a Time-sensitive Customer Churn Prediction (TCCP) framework based on Positive and Unlabeled (PU) learning technique. Specifically, we obtain the recent data by shortening the...

  19. Process for the production of 238Pu16O2

    International Nuclear Information System (INIS)

    Lins, W.

    1976-01-01

    For use as a power source in heart pacers, plutonium dioxide having a naturally occurring oxygen isotope composition is converted into solid phase PuCl 3 which is subsequently oxidized to form plutonium dioxide of the desired isotope composition by means of water vapor, the oxygen component of which consists essentially of the isotope 16 O. Apparatus suited for this purpose is also described

  20. Method of recovery of U, Pu and their compounds

    International Nuclear Information System (INIS)

    Cech, B.; Kaderabek, E.; Hanslik, T.

    1977-01-01

    A method is proposed of removing metal sheaths consisting of either Zr or Nb or Ti or an alloy of at least two of the metals from ceramic nuclear fuel based on U or Pu compounds. The system is exposed to hydrogen, preferably at temperatures of 250 to 460 degC and pressures of 20 to 50 at. The resulting zirconium hydride or hydrides of other metals is separated, eg., mechanically. (M.K.)

  1. Dynamic effect analysis in 240Pu fission at low energy

    International Nuclear Information System (INIS)

    Patin, Y.; Lachkar, J.; Sigaud, J.

    1975-01-01

    The variations of kinetic and excitation energies and fragment masses have been analyzed as a function of the fissioning nucleus excitation energy. Most interest has been taken in the fission of 240 Pu where many experimental data have been reported. The results tend, in the whole, to illustrate the existence of two modes of fission; the first one is superfluid, the other is strongly damped in the last stage of the fission process [fr

  2. Plutonium activities and 240Pu/ 239Pu atom ratios in sediment cores from the east China sea and Okinawa Trough: Sources and inventories

    Science.gov (United States)

    Wang, Zhong-liang; Yamada, Masatoshi

    2005-05-01

    Plutonium concentrations and 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry after separation using ion-exchange chromatography. The results showed that 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediments, ranging from 0.21 to 0.33, were much higher than the reported value of global fallout (0.18). The highest 240Pu/ 239Pu ratios (0.32-0.33) were observed in the deepest Okinawa Trough sediment samples. These ratios suggested the US nuclear weapons tests in the early 1950s at the Pacific Proving Grounds in the Marshall Islands were a major source of plutonium in the East China Sea and Okinawa Trough sediments, in addition to the global fallout source. It was proposed that close-in fallout plutonium was delivered from the Pacific Proving Grounds test sites via early direct tropospheric fallout and transportation by the North Pacific Equatorial Circulation system and Kuroshio Current into the Okinawa Trough and East China Sea. The total 239 + 240 Pu inventories in the cores were about 150-200% of that expected from direct global fallout; about 46-67% of the total inventories were delivered from the Pacific Proving Grounds. Much higher 239 + 240 Pu inventories were observed in the East China Sea sediments than in sediments of the Okinawa Trough, because in the open oceans, part of the 239 + 240 Pu was still retained in the water column, and continued Pu scavenging was higher over the margin than the trough. According to the vertical distributions of 239 + 240 Pu activities and 240Pu/ 239Pu atom ratios in these cores, it was concluded that sediment mixing was the dominant process in controlling profiles of plutonium in this area. Faster mixing in the coastal samples has homogenized the entire 240Pu/ 239Pu ratio record today; slightly slower mixing and less scavenging in the Okinawa Trough have left the surface sediment ratios closer

  3. Study of phase equilibria in function of temperature in UO2-PuO2-Pu2O3 system for nuclear ceramics with high plutonium contents

    International Nuclear Information System (INIS)

    Truphemus, Thibaut

    2013-01-01

    In the UO 2 -PuO 2 -Pu 2 O 3 section, a monophasic (U 1-y ,Pu y )O 2-x domain is stable for y≤0,20 at 25 C and up to solid-liquid equilibrium. At higher Pu content, phase equilibria are more unclear with a phase separation process. The main objective of this work consisted in upgrading the representation of this system for 0,15≤y≤0,65 and 25≤T(C)≤1500. At 25 C, a miscibility gap composed by two different (U 1-y ,Pu y )O 2-x phases has been observed for y≤0,45, with one very closed to stoichiometric state (Oxygen/Metal=2) and one other very reduced. For the first time, a triphasic domain has been characterized at higher Pu contents, with two (U 1-y ,Pu y )O 2-x phases near y=0,45 and one (U 1-y ,Pu y ) 2 O 3 phase with a low U content inside. Concerning the study in function of temperature, we have demonstrated that phase separation temperature increase when Pu content grows. Several representations have been established. At 200 C, the representation is closed to that at 25 C. At 400 C, the phase separation have been specified at a lower Pu content than that of literature: y=0,35. At 600 C, our results have clarified the section, until then very unclear, with a phase separation appearing at y=0,60.The microstructural analysis has clearly demonstrated the significant impact of the phase separation on the material. Indeed many cracks have been observed in our samples, and quantity of these defects increases when Pu content grows. (author) [fr

  4. Pu-238 assay performance with the Canberra IQ3 system

    Energy Technology Data Exchange (ETDEWEB)

    Booth, L.; Gillespie, B.; Seaman, G.

    1997-11-01

    Canberra Industries has recently completed a demonstration project at the Westinghouse Savannah River Site (WSRC) to characterize 55-gallon drums containing Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 contaminated waste. The goal of this project was to detect and quantify Pu-238 waste to detection limits of less than 50 nCi/g using gamma assay techniques. This would permit reclassification of these drums from transuranic (TRU) waste to low-level waste (LLW). The instrument used for this assay was a Canberra IQ3 high sensitivity gamma assay system, mounted in a trailer. The results of the measurements demonstrate achievement of detection levels as low as 1 nCi/g for low density waste drums, and good correlation with known concentrations in several test drums. In addition, the data demonstrates significant advantages for using large area low-energy germanium detectors for achieving the lowest possible MDAs for gamma rays in the 80-250 keV range. 1 fig., 2 tabs.

  5. Uso de contraceptivos por puérperas adolescentes

    Directory of Open Access Journals (Sweden)

    Fernanda Schulz da Rosa

    2014-07-01

    Full Text Available Objetivo: Indagar el uso de métodos contraceptivos por las puérperas adolescentes a fin de relacionar su (desuso con el embarazo en la adolescencia. Método: Estudio transversal, descriptivo, realizado por medio de un instrumento estructurado con 181 puérperas adolescentes que tuvieron sus partos en el hospital participante de la investigación. Los datos fueron recolectados en el período de diciembre de 2008 a diciembre de 2009. Resultados: El 64,1% de las puérperas usaba algún método contraceptivo antes del embarazo; los métodos más utilizados fueron el anticoncepcional oral (51% y el preservativo masculino (29%. Para el 75% de las adolescentes el embarazo fue planeado y justificado por el deseo y la voluntad propia de experimentar la maternidad. Conclusión: Considerando que casi la mitad de las adolescentes entrevistadas deseaba el embarazo, se deduce que investigar y discutir apenas el uso o no de los métodos contraceptivos no es adecuado. Es necesario profundizar las investigaciones acerca de los significados de ser madre en la adolescencia.

  6. Direct fabrication of 238PuO2 fuel forms

    International Nuclear Information System (INIS)

    Burney, G.A.; Congdon, J.W.

    1982-07-01

    The current process for the fabrication of 238 PuO 2 heat sources includes precipitation of small particle plutonium oxalate crystals (4 to 6 μm diameter), a calcination to PuO 2 , ball milling, cold pressing, granulation (60 to 125 μm), and granule sintering prior to hot pressing the fuel pellet. A new two-step direct-strike Pu(III) oxalate precipitation method which yields mainly large well-developed rosettes (50 to 100 μm diameter) has been demonstrated in the laboratory and in the plant. These large rosettes are formed by agglomeration of small (2 to 4 μm) crystals, and after calcining and sintering, were directly hot pressed into fuel forms, thus eliminating several of the powder conditioning steps. Conditions for direct hot pressing of the large heat-treated rosettes were determined and a full-scale General Purpose Heat Source pellet was fabricated. The pellet had the desired granule-type microstructure to provide dimensional stability at high temperature. 27 figures

  7. Soil components that influence the chemical behavior of 239Pu

    International Nuclear Information System (INIS)

    Nishita, H.; Hamilton, M.

    1978-08-01

    Soil components that influence the extractability of 239 Pu from an artificially contaminated kaolinitic soil in relation to pH have been examined. This was done by using an equilibrium batch technique with CH 3 COOH--NH 4 OH and HNO 3 --NaOH extracting systems. Soil organic matter and free iron oxides had an appreciable effect depending on the pH and the extracting system. The free silica and alumina and amorphous alumino-silicates had lesser influence. With the untreated soil (control), the CH 3 COOH--NH 4 OH system generally extracted more 239 Pu than did the HNO 3 --NaOH system in the acidic pH range, whereas the latter system extracted markedly greater amounts of it in the alkaline pH range. With the soil from which the organic matter was removed, the CH 3 COOH--NH 4 OH system extracted appreciably greater amounts of 239 Pu than the HNO 3 --NaOH system in the acidic pH range, but there was only little, if any, difference between the two extracting systems in the alkaline pH range. The causes and the implications of these results are discussed

  8. Analysis and composition of the first U-Pu charge (0,043 per cent of Pu); Analyse et constitution du 1. jeu U-Pu (0,043 pour cent de Pu)

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, J P; Lapparent, D de; Lourme, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Checking the homogeneity in the content of plutonium of 0,043 per cent Pu-natural uranium alloy slugs has been made by Pu 240 and U 238 spontaneous fissions neutrons counting. The purpose of the test was to select groups of slugs to be correctly associated into fuel rods for critical experiments. General technic for spontaneous fissions counting, then elaboration of data in view of ranking the slugs are described. Results are given for this particular case. (authors) [French] On a effectue un controle d'homogeneite de teneur en plutonium sur des billettes d'alliage 0,043 pour cent Pu-uranium naturel, par comptage des fissions spontanees du plutonium 240 et de l'uranium 238. Le but du controle etait de permettre une association correcte de ces billettes a l'interieur des elements combustibles destines a servir dans des experiences critiques. On indique la methode generale de comptage des fissions spontanees, puis le depouillement des donnees en vue du classement des barreaux. Les resultats pour ce cas particulier sont donnes dans le rapport. (auteurs)

  9. Irradiated uranium reprocessing, Final report I-VI, Part V - report on development of laboratory extraction procedure for separation of U, Pu, and FP on the tracer level; Prerada ozracenog urana. Zavrani izvestaj - I-VI, V Deo - Izvestaj o razradi laboratorijskog procesa ekstrakcije za odvajanje U, Pu i FP na nivou obelezavaca

    Energy Technology Data Exchange (ETDEWEB)

    Gal, I [Institute of Nuclear Sciences Boris Kidric, Odeljenje za eksploataciju nuklearnog goriva, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    A laboratory extraction procedure was developed for separation of uranium, plutonium and fission products from the nitric solution. The procedure would be applied for uranium and spent fuel from the RA reactor in Vinca. This is a Purex type of procedure adapted for laboratory purposes. Experimental data are obtained by using syntetic nitric uranium solutions with Pu and fission products additions as tracers. A device for completing the process was constructed.

  10. 76 FR 70883 - Clothing Allowance

    Science.gov (United States)

    2011-11-16

    ... prescription skin cream for the ``face, neck, hands, arms, or any area not covered by clothing may come into... the clothing or outergarment due to a second appliance or medication.'' This language will clarify that a second clothing allowance may be paid when a second appliance and/or medication increases the...

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Y.; Uchida, S.; Tagami, K.; Yoshida, S. [Environmental and Toxicological Researches Group, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, 263-8555 Chiba (Japan); Hamilton, T.; Robison, W. [Health and Ecological Assessment Division, Lawrence Livermore National Laboratory, P.O. Box 808, L-453, 94551-0808 Livermore, CA (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    2001-01-01

    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

  14. The removal of inhaled 239Pu and 238Pu from beagle dogs by lung lavage and chelation treatment

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Miglio, J.J.; Slauson, D.O.; McClellan, R.O.

    1976-01-01

    Studies were conducted in beagle dogs to determine the efficiency of treatment by lung lavage and injections of chelating agents in removing inhaled plutonium of varied chemical forms and particle sizes. Polydisperse aerosols of 239 Pu were produced at different temperatures from 325 0 C to 1150 0 C to evaluate the effect of the chemical form of the particles. Aerosols of 238 Pu were produced at 1150 0 C only but were of different particle size or size distributions. Three dogs that inhaled each different plutonium aerosol were treated by lung lavages starting two days after the exposure. Subsequent lavages were performed on days 7, 10, 14, 21, 28, 35, 42, and 49 after exposure. Intravenous injections of 100 mg of diethylenetriaminepentaacetic acid (DTPA) as the calcium salt were given on days 1, 2, 3 and 4 after exposure and twice weekly thereafter to the time of sacrifice, 56 days after exposure. The 10 lung lavages removed from 18 to 49% of the initial lung burden of plutonium. The recovery of plutonium by lavage was similar irrespective of the temperature at which the aerosol was produced, however, lavage recovery decreased somewhat with increasing particle size. The efficacy of DTPA treatment increased with decreasing production temperature of the 239 Pu. Treatment with DTPA was not affected by particle size of the 0.8- and 1.9-μm monodisperse 239 Pu aerosol. The effectiveness of lung lavage decreased as the solubility of the aerosol particles increased whereas the effectiveness of the DTPA treatment increased as the solubility of the inhaled aerosol increased as shown by the lowest temperature aerosol and the aerosol-containing soluble fraction. These findings correlated qualitatively with a 2-hour in-vitro solubility test on the exposure aerosols. (author)

  15. Complexation studies of actinides (U, Pu, Am) with linear polyamino-carboxylate ligands and sidero-chelates; Etudes de la chelation d'actinides (U, Pu, Am) par des ligands polyaminocarboxylate lineaires et des siderochelates d'interet environnemental

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, L.V.

    2010-11-25

    As part of our research endeavour aimed at developing and improving decontamination processes of wastewater containing alpha emitters, physico-chemical complexation studies of actinides (U, Pu, Am) with organic open-chain ligands such as poly-aminocarboxylic acids (H{sub 4}EDTA) and sidero-chelates (di-hydroxamic acids and desferrioxamine B) have been carried out. Gaining a clear understanding of the coordination properties of the targeted actinides is an essential step towards the selection of the most appropriate chelating agents that will exhibit high uptake efficiencies. EXAFS (Extended X-ray Absorption Fine Structure) measurements at the ESRF synchrotron enabled to elucidate the coordination scheme of uranium and plutonium complexes. Solution thermodynamic investigations were intended to provide valuable information about the nature and the stability of the uranium(VI) and americium(III) complexes prevailing at a given pH in solution. The set of stability constants determined from potentiometric and UV-visible spectrophotometric titrations, allowed to predict the speciation of the selected actinides in presence of the aforementioned ligands and to determine the pH range required for achieving 'ultimate' decontamination. (author) [French] Dans le cadre du developpement et de l'amelioration des procedes de decontamination d'effluents aqueux contamines par des radioelements emetteurs alpha, des etudes physico-chimiques sur la complexation des actinides (U, Pu, Am) avec des ligands organiques tels que des acides polyaminocarboxyliques lineaires (H{sub 4}EDTA) et des siderochelates (acides dihydroxamiques et desferrioxamine B) ont ete effectuees. La comprehension des proprietes de coordination est une etape essentielle pour selectionner les meilleurs agents chelatants qui se montreront efficaces dans le traitement des effluents. Les schemas de coordination des complexes d'uranium et de plutonium avec ces ligands ont ete determines a l

  16. Influence of the allotropic beta to alpha transformation and of oxygen on the distribution of plutonium in Zr-Pu and Ti-Pu dilute alloys

    CERN Document Server

    Languille, A; Remy, C

    1972-01-01

    Ti-Pu, Zr-Pu and Ti-U alloys, annealed above the transformation point, can show major segregation after cooling. The segregations increase with oxygen content. Annealing at high temperatures followed by severe quenching can cause them to disappear. (7 refs).

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

    International Nuclear Information System (INIS)

    Mitchell, P.I.; Vintro, L.L.; Gasco, C.; Sanchez-Cabeza, J.A.

    1995-01-01

    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 240 Pu/ 239 Pu atom ratio of ∼0.18. Measurements of perturbations in this ratio at various sites which had been subjected to close-in fallout, mainly from surface-based testing, has confirmed the feasibility of using this ratio to distinguish plutonium from different fallout sources. In the present study, the 240 Pu/ 239 Pu ratio has been examined in samples of sediment 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 240 Pu/ 239 Pu ratio was measured by high-resolution alpha spectrometry and spectral deconvolution. The analytical results showed that at Thule the mean 240 Pu/ 239 Pu atom ratio was 0.033±0.004, while at Palomares the equivalent ratio appeared to be significantly higher at 0.056±0.003. Both ratios are consistent with those reported for soils samples at the Nevada site and Nagasaki, and are clearly indicative of weapons-grade plutonium. 27 refs., 1 fig., 2 tabs

  18. Synthesis and evaluation of complexing and extracting properties of diamides for the U(VI)/Pu(IV) partitioning

    International Nuclear Information System (INIS)

    Wahu, S.

    2012-01-01

    This work concerns the synthesis and evaluation of new diamides for co-extraction of U(VI) and Pu(IV) from spent nuclear fuels in concentrated nitric acid medium and the subsequent selective back-extraction of Pu(IV) at lower nitric acidity. Thus, three diamides series, namely R 2 NOC(CH 2 ) n CONR 2 , RR'NOC(CH 2 ) n CONRR' and R 2 NOC(CH 2 CHR')CONR 2 (series 1, 2 and 3, respectively) were synthesized and studied in the expectation to establish a structure-activity relationship regarding the extraction properties of such compounds towards actinides. Extraction tests showed that these diamides can effectively and selectively extract U(VI) and Pu(IV) from Am(III) at high acidity. In addition, it was found that the selective back-extraction of Pu(IV) from U(VI) can be achieved, as expected, merely by changing the acidity, when the nitrogen atoms of these diamides are substituted by branched alkyl chains. The mode of coordination of actinides by the above diamides has also been studied through the use of short chain diamides model compounds, allowing the crystallization of the actinide complexes and, thus, their characterization by X-ray diffraction. EXAFS investigation suggested that the uranium coordination sphere in the complexes formed with long chain diamides and extracted into the organic phase is identical to the one observed in U(VI) complexes obtained with short chain diamides model compounds. However, the stoichiometry of model complexes is 1:1, UO 2 (NO 3 ) 2 TEDA, whereas extracted U(VI) complexes exhibit 1:2 stoichiometry, UO 2 (NO 3 ) 2 (TEHDA) 2 . Finally, Th (IV) complexes were also prepared and characterized and further compared to U(VI) complexes. (author) [fr

  19. An ab initio study of plutonium oxides surfaces; Etude ab initio des surfaces d'oxydes de Pu

    Energy Technology Data Exchange (ETDEWEB)

    Jomard, G.; Bottin, F.; Amadon, B

    2007-07-01

    By means of first-principles calculations, we have studied the atomic structure as well as the thermodynamic stability of various plutonium dioxide surfaces in function of their environment (in terms of oxygen partial pressure and temperature). All these simulations have been performed with the ABINIT code. It is well known that DFT fails to describe correctly plutonium-based materials since 5f electrons in such systems are strongly correlated. In order to go beyond DFT, we have treated PuO{sub 2} and {beta}-Pu{sub 2}O{sub 3} in a DFT+U framework. We show that the couple of parameters (U,J) that works well for pure Pu is also well designed for describing ground state (GS) properties of these two oxides. The major improvement with respect with DFT is that we are able to predict an insulating GS in agreement with experiments. The presence of a gap in the DOS (Density of States) of plutonium oxides should play a significant role in the predicted surface reactivity. However, performing DFT+U calculations on surfaces of plutonium oxide from scratch was too ambitious. That is why we decided, as a first step, to study the stability of the (100), (110) and (111) surfaces of PuO{sub 2} in a DFT-GGA framework. For each of these orientations, we considered various terminations. These ab initio results have been introduced in a thermodynamic model which allows us to predict the relative stability of the different terminations as a function of temperature and oxygen partial pressure (p{sub O{sub 2}}). We conclude that at room temperature and for p{sub O{sub 2}}{approx}10 atm., the polar O{sub 2}-(100) termination is favoured. The stabilization of such a polar stoichiometric surface is surprising and should be confirmed by DFT+U calculations before any final conclusion. (authors)

  20. Integral data evaluation of stainless steel, 239Pu, 240Pu, and H2O for homogeneous plutonium systems

    International Nuclear Information System (INIS)

    Jenquin, U.P.; Thompson, J.K.; Trapp, T.J.; Kottwitz, D.A.

    1979-08-01

    Theory-experiment correlations of plutonium-fueled systems using ENDF/B cross-section data have discrepancies which could be due to cross-section data, theoretical methods, and/or interpretation of the experiment. Analyses of homogeneous plutonium critical experiments were performed to determine where cross section deficiencies may exist. New thermal cross-section data (0.3 eV) were generated for 239 Pu and 240 Pu capture, fission, and neutrons per fission. Two scattering kernels for hydrogen bound in water were also generated. Calculated values of k/sub eff/ using these new data were compared with corresponding values using ENDF/B-IV data. The results indicate that the 240 Pu resonance data are sufficiently well known for hydrogen-moderated plutonium systems. In systems using stainless steel as structural and/or neutron control, a large fraction of the neutron absorptions occur in the stainless steel. Analyses of several systems containing stainless steel indicate that the uncertainty in calculated values of k/sub eff/ is small using current estimates of the uncertainties in the cross sections. 20 figures, 30 tables

  1. Comparison of Pu metabolism and pulmonary tumors in dogs and rats exposed to 239PuO2

    International Nuclear Information System (INIS)

    Mahaffey, J.A.; Sanders, C.L.; Dagle, G.E.; Park, J.F.

    The dose-effect relationships of dogs and rats exposed by inhalation to 239 PuO 2 were compared to evaluate parameters that may provide a better understanding for extrapolating these laboratory animal results to humans. Comparisons were made on animals with lifetime lung doses between 1400 and 11,000 rad. Parameters compared included survival; Pu clearance and translocation; and time of occurrence, incidence and histopathology of pulmonary tumors. The group means for lifetime dose to lung were not significantly different between dogs and rats, but when survival time was expressed as the percentage of maximum life expectancy (MLE), the mean survival time of dogs was 40% of MLE and of rats was 56% of MLE. Lung tumors were the causes of death in 84% of the dogs and 54% of the rats; the mean survival time to lung tumor was 44% of MLE for dogs, compared to 57% of MLE for rats. Whole-body clearance of plutonium was slower in dogs. More Pu translocated to the thoracic lymph nodes, liver, and skeleton in the dogs than in rats. Estimates of species differences in lung clearance were dependent on the methods of estimating initial lung burden. There were parameters with qualitative and quantitative similarities in dogs and rats. Quantitative differences between species, generally within a factor of two, suggested that more reliable dosimetry estimates are needed to make quantitative extrapolation between species

  2. Surfaces allowing for fractional statistics

    International Nuclear Information System (INIS)

    Aneziris, Charilaos.

    1992-07-01

    In this paper we give a necessary condition in order for a geometrical surface to allow for Abelian fractional statistics. In particular, we show that such statistics is possible only for two-dimentional oriented surfaces of genus zero, namely the sphere S 2 , the plane R 2 and the cylindrical surface R 1 *S 1 , and in general the connected sum of n planes R 2 -R 2 -R 2 -...-R 2 . (Author)

  3. Influence of process parameters on the fabrication of UO2-PuO2 pellets using the granulation technique

    International Nuclear Information System (INIS)

    Vollath, D.; Wedemeyer, H.

    1982-01-01

    The preparation of UO 2 -PuO 2 fuel pellets from ground and granulated powders results in the formation of mixed oxide solid solutions which is decisive for the solubility of the fuel. Compared with granulated powders made from sintered and ground material, the compaction of green powders leads to much lower compaction densities at the same compaction pressure. Discontinuities of the porosity of sintered pellets made from long-time ground powders probably reflect the rupture of the granulate structure during compaction. Unusual high values of contact numbers obtained by gas effusion measurements indicate a network of cracks in the sintered material. (orig.)

  4. Apparent formation constants of Pu(IV) and Th(IV) with humic acids determined by solvent extraction method

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, T.; Aoyama, S.; Yoshida, H.; Kobayashi, T.; Takagi, I. [Tokyo Univ. (Japan). Dept. of Nuclear Engineering; Kulyako, Y.; Samsonov, M.; Miyasoedov, B. [Russian Academy of Sciences, Moscow (Russian Federation). V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI); Moriyama, H. [Kyoto Univ. (Japan). Research Reactor Inst.

    2012-07-01

    Apparent formation constants of Pu(IV) and Th(IV) with two kinds of humic acids were determined in 0.1 M NaClO{sub 4} at 25 C using a solvent extraction method with thenoyltrifluoroacetone in xylene. The acid dissociation constants of humic acids were also measured by potentiometric titration and used as the degree of dissociation for calculating the formation constants. The effect of solution conditions, such as the pH, the initial metal and humic acid concentrations, and the ionic strength, on the formation constants was examined. The obtained data were compared with the ones in the literature. (orig.)

  5. Comparison of rats and dogs exposed to 239PuO2

    International Nuclear Information System (INIS)

    Mahaffey, J.A.; Sanders, C.L.; Park, J.F.; Dagle, G.E.

    1979-01-01

    Rats and dogs inhaled aerosols of 239 PuO 2 at comparable ages relative to their lifespan. Both received a single exposure. The estimated lung doses at death in dogs were between 1100 and 11,000 rad. From two inhalation experiments, rats receiving doses in this range were chosen from the high-level exposed animals for comparison. Based on this data base, several comparisons were investigated. Metabolism of the material was compared for all animals and for animals which developed lung tumors. The differences in histopathology and tumor incidence in the lung were also reviewed. Although there were several differences between species, there were also many similarities. On-going research in dogs should produce data which will allow clarification of these relationships

  6. Effect of TiO{sub 2} additive on the sintering of nuclear fuel (U,Pu)O{sub 2}. Contribution of surface diffusion to plutonium distribution; Influence de l`ajout de TiO{sub 2} sur l`aptitude au frittage du combustible nucleaire (U,Pu)O{sub 2}. Contribution de la diffusion de surface a la repartition du plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Bremier, Stephane [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France)

    1997-12-19

    the optimizing the temperature conditions, the oxygen potential as sintering gas and the additive concentration in order to obtain a homogeneous (U,Pu)O{sub 2} solid solution independently of the degree of heterogeneity of the initial oxide mixtures 98 refs., 60 figs., 25 tabs.

  7. Contribution to the study of U-Ti and U-Pu-Ti carbides

    International Nuclear Information System (INIS)

    Milet, C.A.

    1968-01-01

    After having discussed the reasons to use (U,Pu) carbides as fast reactor fuel, we examine the influence of the addition of titanium to these carbides. A preliminary study has been done on the system of U-C-Ti and some properties have been measured such as: density, thermal expansion, electrical resistivity, atmospheric corrosion and compatibility with stainless steel. The systems U-Pu-C-Ti (Pu/U + Pu equal to 15 per cent) and U-C-Ti have been found to be very similar. There exists a two phases region (U,Pu)C + TiC, an eutectic between (U,Pu)C and TiC for approximately 15 at %. The solubilities of U + Pu in TiC and of Ti in (U,Pu)C is less than 1 % at. The addition of titanium does not markedly change thermal expansion coefficients of (U,Pu)C. However the resistance to atmospheric corrosion and compatibility with stainless steel is improved. Thermal conductivity, calculated from electrical resistivity, has increased. On the other side, the density of fissile material is lowered. The combination of (U,Pu)C + TiC seems to be the most promising alloy for application as nuclear fuel. (author) [fr

  8. The hematopoietic transcription factor PU.1 regulates RANK gene expression in myeloid progenitors

    International Nuclear Information System (INIS)

    Kwon, Oh Hyung; Lee, Chong-Kil; Lee, Young Ik; Paik, Sang-Gi; Lee, Hyun-Jun

    2005-01-01

    Osteoclasts are bone resorbing cells of hematopoietic origin. The hematopoietic transcription factor PU.1 is critical for osteoclastogenesis; however, the molecular mechanisms of PU.1-regulated osteoclastogenesis have not been explored. Here, we present evidence that the receptor activator of nuclear factor κB (RANK) gene that has been shown to be crucial for osteoclastogenesis is a transcriptional target of PU.1. The PU.1 -/- progenitor cells failed to express the RANK gene and reconstitution of PU.1 in these cells induced RANK expression. Treatment of the PU.1 reconstituted cells with M-CSF and RANKL further augmented the RANK gene expression. To explore the regulatory mechanism of the RANK gene expression by PU.1, we have cloned the human RANK promoter. Transient transfection assays have revealed that the 2.2-kb RANK promoter was functional in a monocyte line RAW264.7, whereas co-transfection of PU.1 transactivated the RANK promoter in HeLa cells. Taken together, these results suggest that PU.1 regulates the RANK gene transcription and this may represent one of the key roles of PU.1 in osteoclast differentiation

  9. Electrochemical investigations of Pu(IV)/Pu(III) redox reaction using graphene modified glassy carbon electrodes and a comparison to the performance of SWCNTs modified glassy carbon electrodes

    International Nuclear Information System (INIS)

    Gupta, Ruma; Gamare, Jayashree; Sharma, Manoj K.; Kamat, J.V.

    2016-01-01

    Highlights: • First report of aqueous electrochemistry of Plutonium on graphene modified electrode. • Graphene is best electrocatalytic material for Pu(IV)/Pu(III) redox couple among the reported modifiers viz. reduced graphene oxide (rGO) and SWCNT’s. • The electrochemical reversibility of Pu(IV)/Pu(III) redox couple improves significantly on graphene modified electrode compared to previously reported rGO & SWCNTs modified electrodes • Donnan interaction between plutonium species and graphene surface offers a possibility for designing a highly sensitive sensor for plutonium • Graphene modified electrode shows higher sensitivity for the determination of plutonium compared to glassy carbon and single walled carbon nanotube modified electrode - Abstract: The work reported in this paper demonstrates for the first time that graphene modified glassy carbon electrode (Gr/GC) show remarkable electrocatalysis towards Pu(IV)/Pu(III) redox reaction and the results were compared with that of single-walled carbon nanotubes modified GC (SWCNTs/GC) and glassy carbon (GC) electrodes. Graphene catalyzes the exchange of current of the Pu(IV)/Pu(III) couple by reducing both the anodic and cathodic overpotentials. The Gr/GC electrode shows higher peak currents (i p ) and smaller peak potential separation (ΔE p ) values than the SWCNTs/GC and GC electrodes. The heterogeneous electron transfer rate constants (k s ), charge transfer coefficients (α) and the diffusion coefficients (D) involved in the electrocatalytic redox reaction were determined. Our observations show that graphene is best electrocatalytic material among both the SWCNTs and GC to study Pu(IV)/Pu(III) redox reaction.

  10. Consistent calculation of the screening and exchange effects in allowed β- transitions

    Science.gov (United States)

    Mougeot, X.; Bisch, C.

    2014-07-01

    The atomic exchange effect has previously been demonstrated to have a great influence at low energy on the Pu241 β- transition. The screening effect has been given as a possible explanation for a remaining discrepancy. Improved calculations have been made to consistently evaluate these two atomic effects, compared here to the recent high-precision measurements of Pu241 and Ni63 β spectra. In this paper a screening correction has been defined to account for the spatial extension of the electron wave functions. Excellent overall agreement of about 1% from 500 eV to the end-point energy has been obtained for both β spectra, which demonstrates that a rather simple β decay model for allowed transitions, including atomic effects within an independent-particle model, is sufficient to describe well the current most precise measurements.

  11. Emission allowances stall in marketplace

    International Nuclear Information System (INIS)

    Malec, W.F.

    1993-01-01

    Misinformation and public misunderstanding have given emissions trading a bad reputation in the public marketplace, says William F. Malec, executive vice president of the Tennessee Valley Authority (TVA), in Knoxville, Tennessee. Media coverage of a May 1992 emissions-allowance trade between TVA and Wisconsin Power and Light open-quotes focused on the agreement's pollution-trading aspects, not its overall potential economic and environmental benefits,close quotes Malec says. Such negative portrayal of TVA's transaction sparked severe public criticism and charges that emissions trading gives utilities the right to pollute. open-quotes The fact is that TVA sought the emissions-trading agreement as a means to reduce overall emissions in the most cost-effective way,close quotes Malec explains. Emissions trading allows a company with emission levels lower than clean-air standards to earn open-quotes credits.close quotes These credits then may be purchased by a company with emission levels that exceed federal standards. Under this arrangement, the environment is protected and companies that buy credits save money because they do not have to purchase expensive emissions-control devices or reduce their production levels. Malec says TVA decided to enter into the emissions-allowance market, not only to cut costs, but also to publicize the existence and benefits of emissions trading. However, TVA's experience proves that open-quotes people will not accept what they do not understand,close quotes concludes Malec, open-quotes especially when complex environmental issues are involved.close quotes

  12. Liquid–liquid extraction of Pu(IV), U(VI) and Am(III) using malonamide in room temperature ionic liquid as diluent

    International Nuclear Information System (INIS)

    Rout, Alok; Venkatesan, K.A.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2012-01-01

    Highlights: ► Extraction of actinides using malonamide in room temperature ionic liquid. ► High distribution ratios of actinides in room temperature ionic liquid. ► Ion exchange mechanism. ► Stoichiometry of extraction. ► High separation factors of U(VI) and Pu(IV) over Am(III) and fission products. - Abstract: The extraction behavior of U(VI), Pu(IV) and Am(III) from nitric acid medium by a solution of N,N-dimethyl-N,N-dioctyl-2-(2-hexyloxyethyl)malonamide (DMDOHEMA) in the room temperature ionic liquid, 1–butyl–3–methylimidazolium bis(trifluoromethanesulfonyl)imide (C 4 mimNTf 2 ), was studied. The distribution ratio of these actinides in DMDOHEMA/C 4 mimNTf 2 was measured as a function of various parameters such as the concentration of nitric acid, DMDOHEMA, NTf 2 − , alkyl chain length of ionic liquid. The extraction of actinides in the absence of DMDOHEMA was insignificant and the distribution ratio achieved in conjunction with C 4 mimNTf 2 , was remarkable. The separation factor of U(VI) and Pu(IV) achieved with the use of DMDOHEMA, ionic liquid was compared with Am(III) and other fission products. The stoichiometry of the metal-solvate was determined to be 1:2 for U(VI) and Pu(IV) and 1:3 for Am(III).

  13. Phosphate functionalized graphene oxide for selective preconcentration of Pu(IV)

    International Nuclear Information System (INIS)

    Chappa, Shankararao; Pandey, Ashok K.

    2015-01-01

    Selective preconcentration of the target ions is a subject of continuous research due to the fact that functional groups are selective to a group of ions/species, and not to a specific ion. Various strategies being explored to make functional group selective to a target ion are based on chemical architecture of functional groups, co-assembly of ligand molecules, synergistic combination of two ligands, formation of size selective cavity, and imprinting using ions as template. Graphene oxide (GO) can be used for removal of radionuclides from aqueous solution having acidity in pH range. As such, GO cannot be used as a sorbent for metal ions from solution having high acidity. GO has epoxy and carboxylic groups that can be used for anchoring functional groups. In the present work, ethylene glycol methacrylate phosphate (EGMP) has been anchored on GO that act as chemical platform. Typically, GO was dispersed in ethanol by sonication for 15 min. In this solution, the EGMP was added and equilibrated for overnight in a shaker at room temp. After equilibrated, GO at the rate EGMP was separated by centrifuge and washed 4-5 times with methanol, EGMP was anchored via C-O-P bonds as confirmed by XPS studies. The sorption studies were carried out using 233 U and 238,239,240 Pu at 3 M HNO 3 using 15 mg of GO at the rate EGMP

  14. Roles of PU.1 in monocyte- and mast cell-specific gene regulation: PU.1 transactivates CIITA pIV in cooperation with IFN-gamma.

    Science.gov (United States)

    Ito, Tomonobu; Nishiyama, Chiharu; Nakano, Nobuhiro; Nishiyama, Makoto; Usui, Yoshihiko; Takeda, Kazuyoshi; Kanada, Shunsuke; Fukuyama, Kanako; Akiba, Hisaya; Tokura, Tomoko; Hara, Mutsuko; Tsuboi, Ryoji; Ogawa, Hideoki; Okumura, Ko

    2009-07-01

    Over-expression of PU.1, a myeloid- and lymphoid-specific transcription factor belonging to the Ets family, induces monocyte-specific gene expression in mast cells. However, the effects of PU.1 on each target gene and the involvement of cytokine signaling in PU.1-mediated gene expression are largely unknown. In the present study, PU.1 was over-expressed in two different types of bone marrow-derived cultured mast cells (BMMCs): BMMCs cultured with IL-3 plus stem cell factor (SCF) and BMMCs cultured with pokeweed mitogen-stimulated spleen-conditioned medium (PWM-SCM). PU.1 over-expression induced expression of MHC class II, CD11b, CD11c and F4/80 on PWM-SCM-cultured BMMCs, whereas IL-3/SCF-cultured BMMCs expressed CD11b and F4/80, but not MHC class II or CD11c. When IFN-gamma was added to the IL-3/SCF-based medium, PU.1 transfectant acquired MHC class II expression, which was abolished by antibody neutralization or in Ifngr(-/-) BMMCs, through the induction of expression of the MHC class II transactivator, CIITA. Real-time PCR detected CIITA mRNA driven by the fourth promoter, pIV, and chromatin immunoprecipitation indicated direct binding of PU.1 to pIV in PU.1-over-expressing BMMCs. PU.1-over-expressing cells showed a marked increase in IL-6 production in response to LPS stimulation in both IL-3/SCF and PWM-SCM cultures. These results suggest that PU.1 overproduction alone is sufficient for both expression of CD11b and F4/80 and for amplification of LPS-induced IL-6 production. However, IFN-gamma stimulation is essential for PU.1-mediated transactivation of CIITA pIV. Reduced expression of mast cell-related molecules and transcription factors GATA-1/2 and up-regulation of C/EBPalpha in PU.1 transfectants indicate that enforced PU.1 suppresses mast cell-specific gene expression through these transcription factors.

  15. Post-Irradiation Examination of 237Np Targets for 238Pu Production

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Robert Noel [ORNL; Baldwin, Charles A [ORNL; Hobbs, Randy W [ORNL; Schmidlin, Joshua E [ORNL

    2015-01-01

    Oak Ridge National Laboratory is recovering the US 238Pu production capability and the first step in the process has been to evaluate the performance of a 237Np target cermet pellet encased in an aluminum clad. The process proceeded in 3 steps; the first step was to irradiate capsules of single pellets composed of NpO2 and aluminum power to examine their shrinkage and gas release. These pellets were formed by compressing sintered NpO2 and aluminum powder in a die at high pressure followed by sintering in a vacuum furnace. Three temperatures were chosen for sintering the solution precipitated NpO2 power used for pellet fabrication. The second step was to irradiate partial targets composed of 8 pellets in a semi-prototypical arrangement at the two best performing sintering temperatures to determine which temperature gave a pellet that performed the best under the actual planned irradiation conditions. The third step was to irradiate ~50 pellets in an actual target configuration at design irradiation conditions to assess pellet shrinkage and gas release, target heat transfer, and dimensional stability. The higher sintering temperature appeared to offer the best performance after one cycle of irradiation by having the least shrinkage, thus keeping the heat transfer gap between the pellets and clad small minimizing the pellet operating temperature. The final result of the testing was a target that can meet the initial production goals, satisfy the reactor safety requirements, and can be fabricated in production quantities. The current focus of the program is to verify that the target can be remotely dissembled, the pellets dissolved, and the 238Pu recovered. Tests are being conducted to examine these concerns and to compare results to code predictions. Once the performance of the full length targets has been quantified, the pellet 237Np loading will be revisited to determine if it can be

  16. Determination of trace Np and Pu by ICP-MS with extraction chromatography in emergency situations

    International Nuclear Information System (INIS)

    Yanqin, Ji; Qing, Tian; Baoming, Shen; Xianzhang, Shao

    2008-01-01

    Full text: An accurate determination of radioculides from various sources in the environmental samples is essential for assessment of the potential hazards and suitable countermeasures both in case of accidents, authorised release and routine surveillance. However, the concentrationof neptunium and plutonium is extremely low in environmental samples, and such samples have a complex matrix composition, which is to be taken into account for a proper analysis. Conventional radiochemical methods such as alpha spectrometry, neutron activation analysis, liquid, liquid scintillation system, fission track and gamma spectrometry for the quantitative determination of neptunium and plutonium often require complicated and time-consuming sample preparation and separation procedures. Due to the large amount of the complex and often unknown matrix, the analysis may also be covered by naturally occurring radionuclides. With the development of new analysis techniques, non-radioactive methods are increasingly used for the determination of trace or ultra-trace radionuclides in environmental samples. Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most suitable analysis techniques for the measurement of the long-lived radionuclides with its high sensitivity, low detection limits, short analysis time, less chemical interferences and multi-elemental capability. The throughput is therefore very high (approx.100 samples a day). The main objective of the present study was to set up of a simple, fast separation procedure to measure Np and Pu in the environmental samples ICP-MS. An unique extraction chromatographic column (TOA: tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M HNO 3 medium on the column and easiy eluted with 0.02 M oxalic acid 0.16 M HNO 3 at 95 C degree. The separated solutions were free from most of the matrix elements and were

  17. Reaction kinetics of irradiation prepolymerized MMA-PU IPN by 5DXC FTIR

    International Nuclear Information System (INIS)

    Wu Yiming; Zhang Zhiping; Luo Ning

    2000-01-01

    The reaction kinetics of irradiation-prepolymerized MMA-PU (polyether) IPNs have been studied by FTIR. The results indicate that the polymerization of each component in the IPN follows its normal distinct reaction mechanism with no mutual interference. Increasing the concentration of TMPTAM (crosslinking agent of PMMA) increased the formation rate of PMMA, while the formation rate of PU networks remained almost the same. Increasing the concentration of TMP (crosslinking agent of PU) increased the formation rate of PU, while the formation rate of PMMA networks decreased. The formation rate of PU was obviously faster than that of PMMA. A theory for the cage effect of the PU network has been proposed. (author)

  18. Chemical thermodynamic representation of (U, Pu, Am)O2-x

    International Nuclear Information System (INIS)

    Osaka, Masahiko; Namekawa, Takashi; Kurosaki, Ken; Yamanaka, Shinsuke

    2005-01-01

    The oxygen potential isotherms of (U, Pu, Am)O 2-x were represented by a chemical thermodynamic model proposed by Lindemer et al. It was assumed in the present model that (U, Pu, Am)O 2-x consisted of the chemical species [UO 2 ], [PuO 2 ], [Pu 4/3 O 2 ], [AmO 2 ] and [Am 5/4 O 2 ] in a pseudo-quaternary system by treating the reduction rates of Pu and Am as identical; furthermore an interaction between [Am 5/4 O 2 ] and [UO 2 ] was introduced. The agreement between analytical and experimental isotherms was good, but the analytical values slightly overestimated the experimental values especially in the case of lower Am content. Adding an interaction between [Am 5/4 O 2 ] and [PuO 2 ] to the model resulted in a better representation

  19. Interatomic potentials for PuC by Chen–Möbius multiple lattice inversion

    International Nuclear Information System (INIS)

    Huang, H.; Meng, D.Q.; Lai, X.C.; Li, G.; Long, Y.

    2013-01-01

    The atomic interactions of PuC with B1 structure were described by Chen–Möbius lattice inversion combined with first-principle calculations. In order to obtain the inversion potential parameters of PuC, three different structures including two virtual crystals were built and the Morse function plus a modified term was adopted to fit the pair-potential curves. The reliability of the inversion potential was tested by checking the stability of the transition of PuC from disordered to ordered state and comparing the calculated and experimental physical and thermal properties of PuC. All the results show that the inversion potential could give a stable and accurate description of the atomic interactions in PuC and the physical and thermal properties of PuC are well reproduced by the potential

  20. Hematological responses after inhaling 238PuO2: An extrapolation from beagle dogs to humans

    International Nuclear Information System (INIS)

    Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

    1994-01-01

    The alpha emitter plutonium-238 ( 238 Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to 238 PuO 2 have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of 238 Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled 238 PuO 2 on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting 238 PuO 2 particles and to extrapolate results to humans